Advances in Software-Defined Technologies for Underwater Acoustic Sensor Networks: A Survey
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paper_title: Autonomous deployment of sensors for maximized coverage and guaranteed connectivity in Underwater Acoustic Sensor Networks

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Self-deployment of sensors with maximized coverage in Underwater Acoustic Sensor Networks (UWASNs) is challenging due to difficulty of access to 3-D underwater environments. The problem is further compounded if the connectivity of the final network is required. One possible approach is to drop the sensors on the surface and then move them to certain depths in the water to maximize the 3-D coverage while maintaining the connectivity. In this paper, we propose a purely distributed node deployment scheme for UWASNs which only requires random dropping of sensors on the water surface. The goal is to expand the initial network to 3-D with maximized coverage and guaranteed connectivity with a surface station. The idea is based on determining the connected dominating set of the initial network and then adjust the depths of all dominatee and dominator neighbors of a particular dominator node for minimizing the coverage overlaps among them while still keeping the connectivity with the dominator. The process starts with a leader node and spans all the dominators in the network for repositioning. Simulations results indicate that connectivity can be guaranteed regardless of the transmission and sensing range ratio with a coverage very close to a coverage-aware deployment approach.
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paper_title: A Survey on Software-Defined Wireless Sensor Networks: Challenges and Design Requirements

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Software defined networking (SDN) brings about innovation, simplicity in network management, and configuration in network computing. Traditional networks often lack the flexibility to bring into effect instant changes because of the rigidity of the network and also the over dependence on proprietary services. SDN decouples the control plane from the data plane, thus moving the control logic from the node to a central controller. A wireless sensor network (WSN) is a great platform for low-rate wireless personal area networks with little resources and short communication ranges. However, as the scale of WSN expands, it faces several challenges, such as network management and heterogeneous-node networks. The SDN approach to WSNs seeks to alleviate most of the challenges and ultimately foster efficiency and sustainability in WSNs. The fusion of these two models gives rise to a new paradigm: Software defined wireless sensor networks (SDWSN). The SDWSN model is also envisioned to play a critical role in the looming Internet of Things paradigm. This paper presents a comprehensive review of the SDWSN literature. Moreover, it delves into some of the challenges facing this paradigm, as well as the major SDWSN design requirements that need to be considered to address these challenges.
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paper_title: Impacts of Deployment Strategies on Localization Performance in Underwater Acoustic Sensor Networks

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When setting up an underwater acoustic sensor network (UASN), node deployment is the first and foremost task, upon which many fundamental network services, such as network topology control, routing, and boundary detection, will be built. While node deployment in 2-D terrestrial wireless sensor networks has been extensively studied, little attention has been received by their 3-D counterparts. This paper aims at analyzing the impacts of node deployment strategies on localization performances in a 3-D environment. More specifically, the simulations conducted in this paper reveal that the regular tetrahedron deployment scheme outperforms the random deployment scheme and the cube deployment scheme in terms of reducing localization error and increasing localization ratio while maintaining the average number of neighboring anchor nodes and network connectivity. Given the fact that random deployment is the primary choice for most of practical applications to date, our results are expected to shed some light on the design of UASNs in the near future.
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paper_title: Ocean current measurement using acoustic sensor network: ‘Challenges, simulation, deployement’

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Underwater Acoustic Sensor Networks (UASNs) are increasingly attracting researchers' attention as they have a wide range of applications among which we can name oceanography and disaster prevention being the main focus of our research. In connection with the principal topics, in this paper, we review the most challenging issues of UASNs that have been discussed in recent publications. These include simulating the underwater environment and networks as well as practical issues and deployment concerns. After investigating the main subjects, we address open areas for research in this field.
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paper_title: On the design of green protocols for underwater sensor networks

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Underwater sensor networks have enabled a new era in scientific and industrial underwater monitoring and exploration applications. However, these networks are energy-constrained and, more problematically, energy-hungry, as a consequence of the use of underwater acoustic links. In this work, we thoroughly review potential techniques for greening underwater sensor networks. In a top-down approach, we discuss the principal design and challenges of the appealing highlighted techniques. We also exemplify their use by surveying recent proposals in underwater sensor networks. Finally, we describe potential future research directions for energy conservation in underwater networks.
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paper_title: Simulation of underwater sensor networks

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This paper highlights some of the key areas of investigation in the network design and analysis of the Deployable Autonomous Distributed System (DADS). DADS is an exploratory research program sponsored by the Office of Naval Research. Simulation was essential in providing system trade-offs and parametric studies of critical system functions. The study of network operations in the DADS environment has resulted in a variety of requirements and lessons learned that are beyond the scope of traditional terrestrial wireless communications systems. This paper also discusses the results of a simulation study of DADS deployment in a typical operational scenario.
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paper_title: Software Defined Wireless Sensor Networks: A Review

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Wireless sensor networks (WSNs) have well known limitations such as battery energy, computing power and bandwidth resources that sometimes limit their widespread use. Current researches are mainly concentrated to propose solutions for nodes energy optimization, network load balancing and the improvement of WSN robustness; however, the software defined network (SDN) paradigm uses the theory of forwarding phase separating from control, simplifying management and configuration of the network to improve network extension and flexibility. It could further optimize WSNs deployment and improve their transmission performance. In this paper, we firstly describe the general architecture and the main features of software defined networks; then, we analyze the current integrated SD-WSN scheme and summarize these results in detail.
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paper_title: Software-Defined Architectures and Technologies for Underwater Wireless Sensor Networks: A Survey

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The ocean covers nearly two-thirds of the surface on the Earth, and there has been great interest in developing underwater wireless sensor networks (UWSNs) to help us explore the ocean realm. A great deal of efforts have been devoted to it, and significant progress has been made since the beginning of 2000s. However, most of the networks are isolatedly developed currently, inherently hardware-based and application-oriented with inflexible closed-form architectures, which are difficult to reconfigure, reprogram and evolve. They also lack the capability in sharing resources, and are far from service-oriented networks. These limitations impair their capacity for wide range of applications. To further propel the development of UWSNs, next-generation UWSNs have been proposed recently, which are robust, flexible, adaptive, programmable, support resource-sharing feature and are easy to manage and evolve. Moreover, a number of novel software-defined techniques and paradigms, such as software-defined radio, cognitive acoustic radio, network function virtualization, software-defined networking, Internet of Underwater Things, and sensor-cloud, have been emerging. These software-defined technologies have the capability of softwarizing network resources, and then redefining them to satisfy diverse application requirements, improve resource utilization efficiency and simplify network management. Consequently, these evolving technologies are envisioned as critical building blocks and major driving forces, which will transform conventional UWSNs toward software-based, programmable, user-customizable, and service-oriented next-generation UWSNs. In this paper, we provide a comprehensive review of existing works on implementing these techniques, and also present discussions for future research. We hope to inspire more active research on these areas and take a step further toward realizing next-generation UWSNs.
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paper_title: Development of software-defined acoustic communication platform and its evaluations

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In recent years, researches of underwater sensor networks have continued to investigate environment and resources of the sea. Acoustic waves are used instead of radio waves for wireless communication in underwater. However, dedicated hardware is very expensive, experiments on the sea are very time-consuming, and huge water spaces are necessary to study the underwater acoustic communication. In this paper, we present a cheap and tractable software-defined acoustic communication platform running on PCs using MATLAB, and evaluate its characteristics in a variety of communication methods by changing modulation schemes, error correction codes, transmission power and frequency by using commercial speaker and microphone devices. Our current implementation achieves data rate of up to 4.5 Kbps.
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paper_title: Challenges and issues in underwater acoustics sensor networks: A review

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The Underwater Acoustic Sensor Networks (UWASN) consists of sensors that are deployed underwater for gathering information for the unexplored parts of oceans or rivers. UWASN consists of variable number of floating and anchored sensors, sink and vehicles that are deployed over an area to be explored. The characteristics of UWASN are mainly node mobility for floating, capacity for data collection and recording and autonomous vehicles which are battery operable. The communication is possible among underwater devices through optical waves, radio waves, electromagnetic and acoustics. Out of these, acoustics communication is best suited as it can carry digital information through underwater channel and can travel to longer distances. The communication can be classified in two parts: Single and multi hoping. But in underwater we use multi-hop communication for sending data from end nodes to sink nodes. The various challenges to UWASN are limited bandwidth, multipath fading, limited battery, limited data capacity and delay in propagation. Hence, in this paper we have focussed on various issues and challenges in underwater wireless sensor networks for acoustic communications.
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paper_title: Key technology and experimental research of underwater acoustic networks

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In recent years, whether autonomous monitoring of ocean environment, deep seabed resources surveying, underwater sensor networks, or military underwater detection networks, etc, there are widespread needs of underwater acoustic networks (UANs). This paper provides a brief overview of the characteristics and advances of UANs, and the main research contents and key technologies of UANs are analyzed, including physical layer technologies, media access control (MAC) protocols and routing protocols. Underwater acoustic communication (UWAC) in the physical layer is the basis for UANs, and its research covers multi-frequency shift keying (MFSK), multi-phase shift keying (MPSK), direct-sequence spread spectrum (DSSS), and orthogonal frequency division multiplexing (OFDM). Common MAC protocols include Time Division Multiple Access (TDMA), ALOHA and MACAW (MACA for Wireless), and are all used in UANs. Routing protocols involve static routing, hybrid routing, and self-organizing routing. The experimental research on underwater acoustic network in the Sanya area is introduced in detail. The network was composed of 15 nodes developed by three institutes. The modems of the nodes deployed used UWAC technology, such as MFSK, MPSK and OFDM. Each network node installed TD, CTD, acoustic Doppler current profiler (ADCP) or other ocean monitoring equipment, gateway was connected with the shore station via radio, and the server of the shore station was connected to the Internet. The network was running for 43 days, and online monitoring of the ocean environment was realized. This paper gives analysis on packet loss ratio, transmission delay and network energy efficiency of the nodes developed by the Hangzhou Applied Acoustics Research Institute. The node packet loss ratio was 2.9%, the average delay was 0.947 minute per hop, when the packet size was 404 bits, and the energy efficiency was 0.7831 bit / J.
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paper_title: Controllers in SDN: A Review Report

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Software-defined networking (SDN) is a networking scenario which changes the traditional network architecture by bringing all control functionalities to a single location and making centralized decisions. Controllers are the brain of SDN architecture, which perform the control decision tasks while routing the packets. Centralized decision capability for routing enhances the network performance. Through this paper, we presented a review report on various available SDN controllers. Along with the SDN introduction, we discuss the prior work in the field. The review states how the centralized decision capability of the controller changes the network architecture with network flexibility and programmability. We also discuss the two categories of the controller along with some popular available controller. For each controller, we discuss the architectural overview, design aspects, and so on. We also evaluate the performance characteristics by using various metrics, such as throughput, response time, and so on. This paper points to the major state-of-the-art controllers used in industry and academia. Our review work covers major popular controllers used in SDN paradigm.
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paper_title: A literature review on Software-Defined Networking (SDN) research topics, challenges and solutions

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Cloud computing data centers are becoming increasingly popular for the provisioning of computing resources. In the past, most of the research works focused on the effective use of the computational and storage resources by employing the Virtualization technology. Network automation and virtualization of data center LAN and WAN were not the primary focus. Recently, a key emerging trend in Cloud computing is that the core systems infrastructure, including compute resources, storage and networking, is increasingly becoming Software-Defined. In particular, instead of being limited by the physical infrastructure, applications and platforms will be able to specify their fine-grained needs, thus precisely defining the virtual environment in which they wish to run. Software-Defined Networking (SDN) plays an important role in paving the way for effectively virtualizing and managing the network resources in an on demand manner. Still, many research challenges remain: how to achieve network Quality of Service (QoS), optimal load balancing, scalability, and security. Hence, it is the main objective of this article to survey the current research work and describes the ongoing efforts to address these challenging issues.
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paper_title: Localization, routing and its security in UWSN — A survey

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Underwater sensor networks are promising apparatus for the discovery of the ocean. For localization and networking protocol, this sensor network requires new robust solution. For terrestrial sensor network various localization algorithms and routing protocols have been proposed, there are very few localization and routing techniques for UWSN. Compare to terrestrial sensor network the features of underwater sensor network are basically different. Underwater acoustic communication is described by stringent physical layer condition with severe bandwidth restrictions. In underwater the uneven rate of sound and the long propagation delay create a distinct set of challenges for localization and routing in UWSN. This paper surveyed the different localization and routing schemes that are applicable to underwater sensor networks, the dispute in meeting the condition created by rising function for such network, attacks, security requirement in UWSN and localization and routing security in UWSN.
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paper_title: A Split Architecture Approach to Terabyte-Scale Caching in a Protocol-Oblivious Forwarding Switch

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Research has proven that in-network caching is an effective way of eliminating redundant network traffic. For a larger cache that scales up to terabytes, a network element must utilize block storage devices. Nevertheless, accessing block devices in packet forwarding paths could be a major performance bottleneck because storage devices are prone to be much slower than memory devices concerning bandwidth and latency. Software-defined networking (SDN) has entered into all aspects of network architecture by separating the control and forwarding plane to make it more programmable and application-aware. Protocol-oblivious forwarding (POF), which is an enhancement to current OpenFlow-based SDN forwarding architecture, enhances the network programmability further. In this paper, we proposed a novel split architecture to cope with the problem of speed mismatch between high-speed packet forwarding and low-speed block I/O operation over POF switches. The issues raised by this split architecture were first explored and could be summarized as packet dependency and protocol conversion. Then, we focused on solving these two problems and proposed an efficient and scalable design. Finally, we conducted extensive experiments to evaluate the split architecture along with the proposed approaches for packet dependency and protocol conversion.
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paper_title: Research on water surface gateway deployment in underwater acoustic sensor networks

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In the underwater sensor network, the deployment of multiple water surface gateway can effectively improve the network capacity, reduce the network delay and save the energy of underwater sensor nodes. Due to the underwater sensor nodes is easily affected by ocean currents affect which occurred in the position drift, surface gateway deployment locations need regular dynamic optimization and update. This paper designs an improved cuckoo optimization algorithm, to achieve a fair and efficient surface gateway layout optimization. At the same time, the influence of different gateway quantity on network capacity and network delay is simulated, which provides scientific decision support for the overall optimization of underwater sensor networks.
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paper_title: Software defined networks for multitenant, multiplatform applications

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Network management in virtualized computing domains is a challenging task in the ever-increasing dimensions of user's interaction, network size, and types of applications. Internet of Things (IoT), smart sensing and communicating devices over the IP domain and strong demand of QoS pose multitude of new challenges. The traditional network management is simply unable to keep up with dynamically varying data management and transport requirements in large-scale multitenant networks. The switches and routers in conventional networks have to be reconfigured for changes in flow requirements, often manually. The Software Defined Networks (SDN) decouples the complexity of state distribution from network specifications. The ‘control plane’ manages data flows, routing and forwarding states through vendor neutral interfaces to the switches. The ‘data plane’ uses the underlying systems that forward traffic to the destinations. Multi-platform, multitenant management support for virtualized domains and cloud computing under SDN architecture has been reviewed in this paper. The scalability, controllability, dependability and security issues in SDN have been discussed along with an overview of core-technologies of SDN, like OpenFlow. A model SDN for distributed flow management in an enterprise environment has also been presented. The challenges and future directions of research are also briefly discussed.
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paper_title: Application identification system for SDN QoS based on machine learning and DNS responses

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In recent years, the demand for application-specific qualify of service (QoS) management has grown. To effectively do application-specific QoS, a system albe to do flow classification at the application level is required. This paper presents an application identification system that can be integrated with a QoS management system in a software defined network (SDN). This paper describes the method to obtain ground truth (label) of the flow from four mainstream operating systems (OS), and the method to classify flow based on supervised machine learning and DNS responses. In our experiment, average F-measure of all applications reached 93.48%. The testing data set contained 294 applications, given that each platform version or execution file of an application was one application. The testing data set included Skype, Facebook, and other popular applications. Results showed that this system can identify application traffic on different platforms with high accuracy.
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paper_title: Evolving trends and challenges in applied underwater acoustic modeling

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Prominent trends and challenges in applied underwater acoustic modeling have been motivated largely by marine-mammal protection research focused on the mitigation of naval-sonar, seismic-source, and pile-driving noise. Channel modeling, underwater-acoustic networks, and communications technologies have evolved to support the increased bandwidths needed for undersea data collection. Energy-flux models, not traditionally used in naval sonar applications, have proved useful for assessing marine-mammal impacts. Developments in inverse sensing include seismic oceanography, which employs low-frequency marine seismic reflection data to image ocean dynamics. Interest in the polar regions has increased due to the well-publicized effects of global warming. Collectively, these trends have added new analytical tools to the existing inventory of propagation, noise, reverberation, and sonar performance models.
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paper_title: Review on Clustering, Coverage and Connectivity in Underwater Wireless Sensor Networks: A Communication Techniques Perspective

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With a wide scope to explore and harness the oceanic sources of interest, the field of underwater wireless sensor networks (UWSNs) is attracting a growing interest of researchers. Owing to the real-time remote data monitoring requirements, underwater acoustic sensor networks (UASNs) emerged as a preferred network to a great extent. In UASN, the limited availability and non-rechargeability of energy resources along with the relative inaccessibility of deployed sensor nodes for energy replenishments necessitated the evolution of several energy optimization techniques. Clustering is one such technique that increases system scalability and reduces energy consumption. Besides clustering, coverage and connectivity are two significant properties that decide the proper detection and communication of events of interest in UWSN due to unstable underwater environment. Underwater communication is also possible with non-acoustic communication techniques like radio frequency, magnetic induction, and underwater free-space optics. In this paper, we surveyed clustering, coverage, and connectivity issues of UASN and qualitatively compared their performance. Particularly, the impact of these non-conventional communication techniques on clustering, coverage, and connectivity aspects is demonstrated. Additionally, we highlighted some key open issues related to the UWSN. This paper provides a broad view of existing algorithms of clustering, coverage, and connectivity based on acoustic communication. It also provides a useful guidance to the researchers in UWSN from various other communication techniques’ perspective.
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paper_title: Software-defined open-architecture modems: Historical review and the NILUS approach

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Flexible/adaptive modems that are reprogramma-ble/reconfigurable at all layers of the communication stack, either by a user or by means of autonomous decisions, are considered as an important enabler for interoperability and cognitive networking in the underwater domain. This paper reviews existing literature on software-defined open-architecture modems (SDOAMs) for underwater communications and networking, and zooms in on relevant R&D efforts currently taking place in a Netherlands-Norway defense cooperation.
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paper_title: Software-Defined Wireless Networking Opportunities and Challenges for Internet-of-Things: A Review

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With the emergence of Internet-of-Things (IoT), there is now growing interest to simplify wireless network controls. This is a very challenging task, comprising information acquisition, information analysis, decision-making, and action implementation on large scale IoT networks. Resulting in research to explore the integration of software-defined networking (SDN) and IoT for a simpler, easier, and strain less network control. SDN is a promising novel paradigm shift which has the capability to enable a simplified and robust programmable wireless network serving an array of physical objects and applications. This paper starts with the emergence of SDN and then highlights recent significant developments in the wireless and optical domains with the aim of integrating SDN and IoT. Challenges in SDN and IoT integration are also discussed from both security and scalability perspectives.
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paper_title: Secure underwater acoustic networks: Current and future research directions

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Underwater Acoustic Networks (UANs) are widely used in various applications such as climate change monitoring, pollution control and tracking, tactical surveillance and offshore exploration. However, limited consideration is given to the security of such networks, despite the fact that the unique characteristics of UANs make these networks vulnerable to various malicious attacks. In this paper, we address future aspects of how to improve security in UANs. We start by reviewing and discussing the state-of-the-art security threats for underwater networks along with their existing solutions. We then identify the open research issues and challenges in the design of secure protocols for communication in UANs. We propose innovative approaches based on node cooperation, cross-layering, software-defined cognitive networking and context-aware communication in order to effectively provision new or strengthen existing security frameworks in UANs. By using these approaches, we address the problem of detecting malicious behaviours and rogue nodes in order to address the major security issues in UANs. We also investigate the use of a covert channel based detection mechanism which needs to be considered when monitoring or deploying UANs at sea. We believe that the issues raised and future possible solution approaches proposed in this paper will greatly help the researchers contributing towards fortifying security in an inherently in-secure UAN.
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paper_title: Joint Routing and Energy Management in UnderWater Acoustic Sensor Networks

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Interest in underwater acoustic sensor networks (UW-ASNs) has rapidly increased with the desire to control the large portion of the world covered by oceans. Fundamental differences between underwater acoustic propagation and terrestrial radio propagation may impose the design of new networking protocols and management schemes. In this paper, we focus on these fundamental differences in order to conceive a balanced routing strategy that overcomes the energy holes problem. Indeed, energy management is one of the major concerns in UW-ASNs due to the limited energy budget of the underwater sensor nodes. In this paper, we tackle the problem of energy holes in UW-ASNs while taking into consideration the unique characteristics of the underwater channel. The main contribution of this study is an in-depth analysis of the impact of these unique underwater characteristics on balancing the energy consumption among all underwater sensors. We prove that we can evenly distribute the transmission load among sensor nodes provided that sensors adjust their communication power when they send or forward the periodically generated data. In particular, we propose a balanced routing strategy along with the associated deployment pattern that meticulously determines the load weight for each possible next hop, that leads to fair energy consumption among all underwater sensors. Consequently, the energy holes problem is overcome and hence the network lifetime is improved.
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paper_title: Efficient Use of Space-Time Clustering for Underwater Acoustic Communications

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Underwater acoustical communication channels are characterized by the spreading of received signals in space (direction of arrival) and in time (delay). The spread is often limited to a small number of space-time clusters. In this paper, the space-time clustering is exploited in a proposed receiver designed for guard-free orthogonal frequency-division multiplexing with superimposed data and pilot signals. For separation of space clusters, the receiver utilizes a vertical linear array (VLA) of hydrophones, whereas for combining delay-spread signals within a space cluster, a time-domain equalizer is used. We compare a number of space-time processing techniques, including a proposed reduced-complexity spatial filter, and show that techniques exploiting the space-time clustering demonstrate an improved detection performance. The comparison is done using signals transmitted by a moving transducer, and recorded on a 14-element nonuniform VLA in sea trials at distances of 46 and 105 km.
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paper_title: An Underwater Sensor Network Deployment Algorithm Based on Submarine Depth

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For three-dimensional underwater wireless sensor networks in anti-submarine,a kind of deployment method based on the prior probability model of submarine depth information is proposed.According to the depth information of the submarine,fewer nodes will go to sleep in order to increase the density of active nodes for the area with larger submarine emergence probability.For the other regions,more nodes will be sleep,to decrease the active node density and reduce coverage ratio.The simulation results show that the algorithm can ensure higher coverage quality,reduce the overall energy consumption of the network,and extend the lifetime of underwater wireless sensor networks.
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paper_title: Underwater Acoustic Networks - Survey on Communication Challenges with Transmission Simulations

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Underwater sensor networks may be used in many underwater applications and some of these applications may transmit large amounts of data. Underwater acoustic communication is limited by several physical factors affecting communication. Time spread caused by multipath effects and frequency selective fading are major concerns.The choice of modulation technique is important. Due to the high data rate required in network applications coherent modulation techniques should be considered. In the choice of multiple access method Code Division Multiple Access is considered the most promising technique because of its robustness and resistance against frequency selective fading. Also by using a Rake receiver multipath arrivals can coherently be combined.To get an idea of multipath effects for different propagation conditions the acoustic modeling program EasyPLR is used. Sound speed profiles from different seasons of 2005 are implemented to display the seasonal variations. The results indicate multipath effects and time spread for all seasons at short range. For ranges up to 3 km time spread is kept at tens of micro seconds.
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paper_title: A Novel SDN Scheme for QoS Path Allocation in Wide Area Networks

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The massive adoption of Cloud services has led to the explosion of traffic transiting over the Cloud infrastructure. Such an impressive evolution of data demand will inevitably be the catalyst of Operator infrastructure transformation. In this context, Software Defined Networking (SDN) is the technology that is shaping the future of carriers' networks. SDN considerably reduces the complexity of managing the network infrastructure while providing tremendous computational power compared to legacy devices. In this paper, we address the resource allocation issue in Wide Area Networks (WAN) while considering the requested QoS. To do so, we design an SD-WAN architecture to enhance the network resources allocation and hence improve the QoS of distributed applications. We formulate first the path computation problem as an Integer Linear Program while taking into consideration both network application requirements and the network occupation status. The problem is then resolved in a polynomial time leveraging the Branch-and-Cut algorithm. Results obtained with our experimental platform, show that the proposed SD-WAN framework outperforms the most prominent related solutions in terms of applications' satisfaction level and consumption of network's resources.
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paper_title: Wireless Software Defined Networking: A Survey and Taxonomy

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One of the primary architectural principles behind the Internet is the use of distributed protocols, which facilitates fault tolerance and distributed management. Unfortunately, having nodes (i.e., switches and routers) perform control decisions independently makes it difficult to control the network or even understand or debug its overall emergent behavior. As a result, networks are often inefficient, unstable, and fragile. This Internet architecture also poses a significant, often insurmountable, challenge to the deployment of new protocols and evolution of existing ones. Software defined networking (SDN) is a recent networking architecture with promising properties relative to these weaknesses in traditional networks. SDN decouples the control plane, which makes the network forwarding decisions, from the data plane, which mainly forwards the data. This decoupling enables more centralized control where coordinated decisions directly guide the network to desired operating conditions. Moreover, decoupling the control enables graceful evolution of protocols, and the deployment of new protocols without having to replace the data plane switches. In this survey, we review recent work that leverages SDN in wireless network settings, where they are not currently widely adopted or well understood. More specifically, we evaluate the use of SDN in four classes of popular wireless networks: cellular, sensor, mesh, and home networks. We classify the different advantages that can be obtained by using SDN across this range of networks, and hope that this classification identifies unexplored opportunities for using SDN to improve the operation and performance of wireless networks.
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paper_title: 47 Evolutionary Control of an Autonomous Field

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An autonomous field of sensor nodes needs to acquire and track targets of interest traversing the field. Small detection ranges limit the detectability of the field. As detections occur in the field detections are transmitted acoustically to a master node. Both detection processing and acoustic communication drain a node's power source. In order to maximize field life, an approach must be developed to control processes carried out in the field. In this paper we develop an adaptive threshold control scheme. This technique will minimize the power consumption while still maintaining the field-level probability of detection. The power consumption of the field of sensor nodes is driven by the false alarm rate and target detection rate at the individual sensor nodes in this problem formulation. The control law to be developed is based upon a stochastic optimization technique known as evolutionary programming. At the end of the paper, a set of results are presented that will show that by dynamically adjusting sensor thresholds and routing structures, the controlled field will have twice the life of the fixed field.
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paper_title: Underwater Acoustic Communications and Networks for the US Navy's Seaweb Program

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At present, the realities of acoustic communications and undersea networks differ substantially from the expectations arising from academic theory and investigation. The issue is not that the fundamentals of communications theory do not apply, but rather the fact that the difficulties of the acoustic channel do not necessarily fit the assumptions underlying conventional applications of that theory. In this paper we describe many of the practical problems that have been addressed over the past ten years of modem development. Some of the issues addressed have an RF analog, but the severity of the channel and the combination of channel constraints and modem-platform operations makes acoustic communications a very different problem. In particular, we address these issues via their impact on physically small, battery powered, DSP-based, omni-directional modems. Next we describe progress toward using commercial acoustic modems as the basis for underwater networks. We discuss design choices at the physical, link, and network layers that are consistent with the compound constraints of the transmission channel and modem.
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paper_title: OpenFlow: a radical new idea in networking

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An open standard that enables software-defined networking.
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paper_title: Firewall application for Floodlight SDN controller

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In this article the authors give a general idea of software-defined networking (SDN). The paper contains a description of Floodlight SDN controller and an issue of network security management. The authors present a set of techniques that provide more security in the controller. They are implemented as a network application and describe the basic mechanism.
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paper_title: Mode decomposition using compressive sensing applied to the SW06 data

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A method for mode decomposition is presented using compressive sensing. Simulated data are used to demonstrate its pro and con compared with conventional methods using eigenvector decomposition. Mode cross-correlation and mode coherence time are studied using narrowband signals collected on a vertical line array during the SW06 experiment, that were transmitted from a moving source with different speeds and along paths with different bottom bathymetry. It is found that the coherence time of the dominant modes is longer than the matched-field coherence time and more sensitive to the source speed than the bathymetry. The decomposed modes can be divided into groups where members of each group are more coherent with each other than with members outside of the group.
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paper_title: The DESERT underwater framework v2: Improved capabilities and extension tools

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The DESERT Underwater emulation system (http://nautilus.dei.unipd.it/desert-underwater), originally designed for testing underwater acoustic networks, has been recently extended. The new framework now includes multi-modal communication functionalities encompassing low rate and high rate acoustics as well as optics, the capability of testing wireless telemetry for underwater equipment, a connection to the most recent version of the World Ocean Simulation System (WOSS), a modification to the RECORDS system for sea trial remote control, and an interface between external tools, e.g., Matlab, and the EvoLogics modem. In addition, experimental activities are now supported by an accurate real-time event scheduler which has been shown to support, among others, long experiments involving time-division multiple-access (TDMA)-based MAC protocols. These additional protocol schemes from the MAC to the application layer (most of which have been tested in controlled environments and sea trials) now make DESERT Underwater a comprehensive tool for underwater network simulation and experimentation. In this paper, we present the new functionalities developed over the last two years.
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paper_title: A preliminary examination of the low-frequency ambient noise field in the South China Sea during the 2001 ASIAEX experiment

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This correspondence presents a preliminary examination of the low frequency ambient noise field measured in the South China Sea component of the Asian Seas International Acoustics Experiment (ASIAEX), concentrating on the frequencies of 50, 100, 200, 400, 800, and 1200 Hz. A two-week-long time series of the noise at these frequencies is examined for structure in both the time and frequency domains. Three features of particular interest in these series are: 1) the noise due to a typhoon, which passed near the experimental site, 2) the weak tidal frequency variability of the noise field, which is probably due to internal tide induced variability in the propagation conditions, and 3) the vertical angle dependence of the noise, particularly as regards the shallow water "noise notch" phenomenon. The acoustic frequency dependence and the vertical dependence of the noise field are also examined over the course of the time series. A simple look at the noise variability statistics is presented. Finally, directions for further analysis are discussed.
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paper_title: Auto-Configuration of ACL Policy in Case of Topology Change in Hybrid SDN

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Software-defined networking (SDN) has emerged as a new network architecture, which decouples both the control and management planes from data plane at forwarding devices. However, SDN deployment is not widely adopted due to the budget constraints of organizations. This is because organizations are always reluctant to invest too much budget to establish a new network infrastructure from scratch. One feasible solution is to deploy a limited number of SDN-enabled devices along with traditional (legacy) network devices in the network of an organization by incrementally replacing traditional network by SDN, which is called hybrid SDN (Hybrid SDN) architecture. Network management and control in Hybrid SDN are vital tasks that require significant effort and resources. Manual handling of these tasks is error prone. Whenever network topology changes, network policies (e.g., access control list) configured at the interfaces of forwarding devices (switches/routers) may be violated. That creates severe security threats for the whole network and degrades the network performance. In this paper, we propose a new approach for Hybrid SDN that auto-detects the interfaces of forwarding devices and network policies that are affected due to change in network topology. In the proposed approach, we model network-wide policy and local policy at forwarding device using a three-tuple and a six-tuple, respectively. We compute graph to represent the topology of the network. By using graph difference technique, we detect a possible change in topology. In the case of topology change, we verify policy for updated topology by traversing tree using six-tuple. If there is any violation in policy implementation, then affected interfaces are indicated and policies that need to be configured are also indicated. Then, policies are configured on the updated topology according to specification in an improved way. Simulation results show that our proposed approach enhances the network efficiency in term of successful packet delivery ratio, the ratio of packets that violated the policy and normalized overhead.
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paper_title: OpenRoads: empowering research in mobile networks

paper_content:

We present OpenRoads, an open-source platform for innovation in mobile networks. OpenRoads enable researchers to innovate using their own production networks, through providing an wireless extension OpenFlow. Therefore, you can think of OpenRoads as "OpenFlow Wireless". The OpenRoads' architecture consists of three layers: flow, slicing and controller. These layers provide flexible control, virtualization and high-level abstraction. This allows researchers to implement wildly different algorithms and run them concurrently in one network. OpenRoads also incorporates multiple wireless technologies, specifically WiFi and WiMAX. We have deployed OpenRoads, and used it as our production network. Our goal here is for those to deploy OpenRoads and build their own experiments on it.
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paper_title: A QoS Framework for SDN-Based Networks

paper_content:

Nowadays, traditional networks are suffering from lack of information, easy management, and hard QoS guarantee. Recently, SDNs overcome these limitations. They provide network agility, programmability, and centralized network control. These features facilitate solving many of the security, performance, management and QoS issues. In this paper, we propose an SDN framework that leverages programmability and centralized control to provide a level of QoS. Knowing the state of the whole network helps optimizing the decision towards enhancing the network efficiency. The presented framework basically contains modules that provide monitoring, route determination, rule preparation, and configuration functionalities. The monitoring module analyzes ports utilization and probs the links delay. The route determination module relies on the shortest path algorithm, with or without QoS guarantee. Two QoS parameters, namely, port utilization and delay are considered in the monitoring and the route determination. The proposed framework is tested in a fat-tree topology with an OpenDayLight (ODL) controller. Experiments are conducted to prove the efficiency of the presented framework over the traditional standalone controller with the built-in features. Results showed that using the presented framework, with or without QoS reduces the overall average delay by 57%, jitter by 25% and packet loss by 67%. Moreover, the monitored port utilization was reduced by 30% on average.
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paper_title: A survey on software defined network approaches for achieving energy efficiency in wireless sensor network

paper_content:

The proliferation of sensor technology in many areas have gained more attention on Wireless Sensor Network (WSN) from both research community and actual user. However, energy consumption continues to be a constrained resource and remains a crucial issue of this technology. Since data transmission and communication in the network consumed a lot of energy in WSN, the activity of the sensor nodes should be altered to prolong the lifetime of the network. To this end, this paper provides the survey on how Software-Defined Networks (SDN) approach has been used to reduce the energy consumption in WSN. Software-defined network is developed with the purpose to facilitate the emergence of the centralized control of the network data-path in which resulted in compliance by decoupling the control and forwarding planes. With this paper, readers can be more understanding better of how software-defined network works and the effectiveness of using software-defined network in handling the shortcomings in WSN.
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paper_title: Open source suites for underwater networking: WOSS and DESERT underwater

paper_content:

Simulation and experimentation of underwater networks entail many challenges, which for the former are mainly related to the accurate modeling of the channel behavior, while they are typically logistic in nature for the latter. In this article, we present our experience with WOSS and DESERT Underwater, two open source suites address both classes of challenges. The suites build on and extend the capa- bilities of ns2 and NS-MIRACLE, two widely known software packages for network simulation. WOSS endows NS-MIRACLE with the capability to generate realistic channel patterns by automatically retrieving and processing the environmental boundary conditions that influence such patterns; DESERT Underwater makes it pos- sible to evolve toward at-sea experiments by reusing the same code written for sim- ulations, thereby minimizing the effort required for network deployment and control. Both suites have been widely tested and used in several projects: some examples are provided in this respect, including an account of some experiments carried out in collaboration with the NATO STO Centre for Maritime Research and Experimentation.
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paper_title: Towards programmable enterprise WLANS with Odin

paper_content:

We present Odin, an SDN framework to introduce programmability in enterprise wireless local area networks (WLANs). Enterprise WLANs need to support a wide range of services and functionalities. This includes authentication, authorization and accounting, policy, mobility and interference management, and load balancing. WLANs also exhibit unique challenges. In particular, access point (AP) association decisions are not made by the infrastructure, but by clients. In addition, the association state machine combined with the broadcast nature of the wireless medium requires keeping track of a large amount of state changes. To this end, Odin builds on a light virtual AP abstraction that greatly simplifies client management. Odin does not require any client side modifications and its design supports WPA2 Enterprise. With Odin, a network operator can implement enterprise WLAN services as network applications. A prototype implementation demonstrates Odin's feasibility.
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paper_title: SEANet G2: toward a high-data-rate software-defined underwater acoustic networking platform

paper_content:

Existing underwater acoustic networking platforms are for the most part based on inflexible hardware and software architectures that can support mostly point-to-point, low-data-rate, delay-tolerant applications. Most commercial devices do not provide neither the sufficient data rates nor the necessary flexibility to support future underwater networking applications and systems. This article discusses a new high-data rate software-defined underwater acoustic networking platform, SEANet G2, able to support higher data rates (megabit/s data rates are foreseen over short range links), spectrum agility, and hardware/software flexibility in support of distributed networked monitoring operations. The article reports on the main architectural choices of the new platform, as well as some preliminary performance evaluation results. Data rates in the order of megabit/s were demonstrated in a controlled lab environment, and, for the first time to the best of our knowledge, data rates of 522kbit/s where obtained in sea trials over short horizontal links (e.g., 10 m) for a BER lower than 10−3.
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paper_title: Revisiting traffic anomaly detection using software defined networking

paper_content:

Despite their exponential growth, home and small office/home office networks continue to be poorly managed. Consequently, security of hosts in most home networks is easily compromised and these hosts are in turn used for largescale malicious activities without the home users' knowledge. We argue that the advent of Software Defined Networking (SDN) provides a unique opportunity to effectively detect and contain network security problems in home and home office networks. We show how four prominent traffic anomaly detection algorithms can be implemented in an SDN context using Openflow compliant switches and NOX as a controller. Our experiments indicate that these algorithms are significantly more accurate in identifying malicious activities in the home networks as compared to the ISP. Furthermore, the efficiency analysis of our SDN implementations on a programmable home network router indicates that the anomaly detectors can operate at line rates without introducing any performance penalties for the home network traffic.
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paper_title: Performance optimisation of control channel in ForCES-based software defined network

paper_content:

The traditional network architecture cannot meet the growing needs of increasingly diverse network applications. The new generation network architectures, software defined network (SDN) which have features of high openness, flexibility, scalability and high controllability have widely been studied. However, a series of new problems are also produced in this new architecture, such as security problem resulted from the high openness, and performance problem resulted from the high flexibility. Currently, the researchers are mainly concentrated in the implementation and standardisation of SDN. There is no good approach to evaluate and optimise the system performance. This studies the performance problems unresolved in SDN research area, and proposed an idea and method to analyse the control channel of ForCES (Forwarding and Control Element Separation)-based SDN by using the stochastic network calculus theory. First, the architecture of ForCES-based SDN is introduced. Then, the performance model of the channel is given. Based on the model, an optimisation method to performance is detailed. This study also gives a simulation by using NS-2 (Network Simulator, Version 2) to verify the correctness and reliability of the performance model.
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paper_title: Network Innovation using OpenFlow: A Survey

paper_content:

OpenFlow is currently the most commonly deployed Software Defined Networking (SDN) technology. SDN consists of decoupling the control and data planes of a network. A software-based controller is responsible for managing the forwarding information of one or more switches; the hardware only handles the forwarding of traffic according to the rules set by the controller. OpenFlow is an SDN technology proposed to standardize the way that a controller communicates with network devices in an SDN architecture. It was proposed to enable researchers to test new ideas in a production environment. OpenFlow provides a specification to migrate the control logic from a switch into the controller. It also defines a protocol for the communication between the controller and the switches. As discussed in this survey paper, OpenFlow-based architectures have specific capabilities that can be exploited by researchers to experiment with new ideas and test novel applications. These capabilities include software-based traffic analysis, centralized control, dynamic updating of forwarding rules and flow abstraction. OpenFlow-based applications have been proposed to ease the configuration of a network, to simplify network management and to add security features, to virtualize networks and data centers and to deploy mobile systems. These applications run on top of networking operating systems such as Nox, Beacon, Maestro, Floodlight, Trema or Node.Flow. Larger scale OpenFlow infrastructures have been deployed to allow the research community to run experiments and test their applications in more realistic scenarios. Also, studies have measured the performance of OpenFlow networks through modelling and experimentation. We describe the challenges facing the large scale deployment of OpenFlow-based networks and we discuss future research directions of this technology.
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paper_title: ElasticTree: Saving Energy in Data Center Networks

paper_content:

Networks are a shared resource connecting critical IT infrastructure, and the general practice is to always leave them on. Yet, meaningful energy savings can result from improving a network's ability to scale up and down, as traffic demands ebb and flow. We present ElasticTree, a network-wide power1 manager, which dynamically adjusts the set of active network elements -- links and switches--to satisfy changing data center traffic loads. ::: ::: We first compare multiple strategies for finding minimum-power network subsets across a range of traffic patterns. We implement and analyze ElasticTree on a prototype testbed built with production OpenFlow switches from three network vendors. Further, we examine the trade-offs between energy efficiency, performance and robustness, with real traces from a production e-commerce website. Our results demonstrate that for data center workloads, ElasticTree can save up to 50% of network energy, while maintaining the ability to handle traffic surges. Our fast heuristic for computing network subsets enables ElasticTree to scale to data centers containing thousands of nodes. We finish by showing how a network admin might configure ElasticTree to satisfy their needs for performance and fault tolerance, while minimizing their network power bill.
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paper_title: Distributed SDN Control: Survey, Taxonomy, and Challenges

paper_content:

As opposed to the decentralized control logic underpinning the devising of the Internet as a complex bundle of box-centric protocols and vertically integrated solutions, the software-defined networking (SDN) paradigm advocates the separation of the control logic from hardware and its centralization in software-based controllers. These key tenets offer new opportunities to introduce innovative applications and incorporate automatic and adaptive control aspects, thereby, easing network management and guaranteeing the user’s quality of experience. Despite the excitement, SDN adoption raises many challenges including the scalability and reliability issues of centralized designs that can be addressed with the physical decentralization of the control plane. However, such physically distributed, but logically centralized systems bring an additional set of challenges. This paper presents a survey on SDN with a special focus on the distributed SDN control. Besides reviewing the SDN concept and studying the SDN architecture as compared to the classical one, the main contribution of this survey is a detailed analysis of state-of-the-art distributed SDN controller platforms which assesses their advantages and drawbacks and classifies them in novel ways (physical and logical classifications) in order to provide useful guidelines for SDN research and deployment initiatives. A thorough discussion on the major challenges of distributed SDN control is also provided along with some insights into emerging and future trends in that area.
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paper_title: OpenFlow: enabling innovation in campus networks

paper_content:

This whitepaper proposes OpenFlow: a way for researchers to run experimental protocols in the networks they use every day. OpenFlow is based on an Ethernet switch, with an internal flow-table, and a standardized interface to add and remove flow entries. Our goal is to encourage networking vendors to add OpenFlow to their switch products for deployment in college campus backbones and wiring closets. We believe that OpenFlow is a pragmatic compromise: on one hand, it allows researchers to run experiments on heterogeneous switches in a uniform way at line-rate and with high port-density; while on the other hand, vendors do not need to expose the internal workings of their switches. In addition to allowing researchers to evaluate their ideas in real-world traffic settings, OpenFlow could serve as a useful campus component in proposed large-scale testbeds like GENI. Two buildings at Stanford University will soon run OpenFlow networks, using commercial Ethernet switches and routers. We will work to encourage deployment at other schools; and We encourage you to consider deploying OpenFlow in your university network too
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paper_title: ForSA — A New Software Defined Network Architecture Based on ForCES

paper_content:

In recent years, SDN (Software Defined Network) as a new network architecture has become the hot research point. Meanwhile, the well-known OpenFlow-based SDN got a lot of attention. But it can't provide a flexible and effective network resource description method. As an open programmable technology, ForCES (Forwarding and Control Element Separation) has also been concerned. However, ForCES is confined within a single network node and cannot be applied to the entire network. This paper proposes a new architecture - ForSA (ForCESbased SDN architecture). The architecture is added a configuration layer based on the traditional SDN architecture, which solves the problem that the northbound interface is not clear between the application layer and the control layer in the SDN architecture. ForSA also implements the compatibility within various forwarding devices in the forwarding layer.
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paper_title: OptoCOMM and SUNSET to enable large data offloading in Underwater Wireless Sensor Networks

paper_content:

In this paper we present the initial implementation of an integrated optical and acoustic system that can enable large data transfer between mobile and static nodes in Underwater Wireless Sensor Networks (UWSNs). The proposed system is based on the OptoCOMM optical modem and on the SUNSET Software Defined Communication Stack (S-SDCS) framework. The OptoCOMM modem allows to overcome the limits of maximum data rate and bandwidth imposed by the use of acoustic communication by providing a data rate of 10Mbps. SUNSET SDCS instead has been used to provide networking and fragmentation capabilities to efficiently offload large data in UWSNs. The performance of the proposed approach has been evaluated through in lab experiments where large files with arbitrary sizes have been optically transferred. The results achieved show that our system is able to transfer up to 1.5 GBytes of data in short time.
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paper_title: Experimental demonstration of OpenFlow control of packet and circuit switches

paper_content:

OpenFlow is presented as a unified control plane and architecture for packet and circuit switched networks. We demonstrate a simple proof-of-concept testbed, where a bidirectional wavelength circuit is dynamically created to transport a TCP flow.
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paper_title: Control and understanding: Owning your home network

paper_content:

Wireless home networks are increasingly deployed in people's homes worldwide. Unfortunately, home networks have evolved using protocols designed for backbone and enterprise networks, which are quite different in scale and character to home networks. We believe this evolution is at the heart of widely observed problems experienced by users managing and using their home networks. In this paper we investigate redesign of the home router to exploit the distinct social and physical characteristics of the home. We extract two key requirements from a range of ethnographic studies: users desire greater understanding of and control over their networks' behaviour. We present our design for a home router that focuses on monitoring and controlling network traffic flows, and so provides a platform for building user interfaces that satisfy these two user requirements. We describe and evaluate our prototype which uses NOX and OpenFlow to provide per-flow control, and a custom DHCP implementation to enable traffic isolation and accurate measurement from the IP layer. It also provides finer-grained per-flow control through interception of wireless association and DNS resolution. We evaluate the impact of these modifications, and thus the applicability of flow-based network management in the home.
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paper_title: Software defined optical networks technology and infrastructure: Enabling software-defined optical network operations

paper_content:

Software-defined networking (SDN) enables programmable SDN control and management functions at a number of layers, allowing applications to control network resources or information across different technology domains, e.g., Ethernet, wireless, and optical. Current cloud-based services are pushing networks to new boundaries by deploying cutting edge optical technologies to provide scalable and flexible services. SDN combined with the latest optical transport technologies, such as elastic optical networks, enables network operators and cloud service providers to customize their infrastructure dynamically to user/application requirements and therefore minimize the extra capital and operational costs required for hosting new services. In this paper a unified control plane architecture based on OpenFlow for optical SDN tailored to cloud services is introduced. Requirements for its implementation are discussed considering emerging optical transport technologies. Implementations of the architecture are proposed and demonstrated across heterogeneous state-of-the-art optical, packet, and IT resource integrated cloud infrastructure. Finally, its performance is evaluated using cloud use cases and its results are discussed.
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paper_title: B4: experience with a globally-deployed software defined wan

paper_content:

We present the design, implementation, and evaluation of B4, a private WAN connecting Google's data centers across the planet. B4 has a number of unique characteristics: i) massive bandwidth requirements deployed to a modest number of sites, ii) elastic traffic demand that seeks to maximize average bandwidth, and iii) full control over the edge servers and network, which enables rate limiting and demand measurement at the edge. These characteristics led to a Software Defined Networking architecture using OpenFlow to control relatively simple switches built from merchant silicon. B4's centralized traffic engineering service drives links to near 100% utilization, while splitting application flows among multiple paths to balance capacity against application priority/demands. We describe experience with three years of B4 production deployment, lessons learned, and areas for future work.
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paper_title: A Survey on Software-Defined Network and OpenFlow: From Concept to Implementation

paper_content:

Software-defined network (SDN) has become one of the most important architectures for the management of largescale complex networks, which may require repolicing or reconfigurations from time to time. SDN achieves easy repolicing by decoupling the control plane from data plane. Thus, the network routers/switches just simply forward packets by following the flow table rules set by the control plane. Currently, OpenFlow is the most popular SDN protocol/standard and has a set of design specifications. Although SDN/OpenFlow is a relatively new area, it has attracted much attention from both academia and industry. In this paper, we will conduct a comprehensive survey of the important topics in SDN/OpenFlow implementation, including the basic concept, applications, language abstraction, controller, virtualization, quality of service, security, and its integration with wireless and optical networks. We will compare the pros and cons of different schemes and discuss the future research trends in this exciting area. This survey can help both industry and academia R&D people to understand the latest progress of SDN/OpenFlow designs.
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paper_title: Towards QoS-enabled SDN networks

paper_content:

SDN networks have become increasingly popular, especially for real time systems. Optimizing the self-defined network cost and performance is thereby primordial. This requires the network to meet real-time requirements and provide guarantees related to bandwidth and packet loss, and associated with the end-to-end delay and jitter which are essential indicators of QoS. This paper is an effort towards QoS-enabled SDN networks that allows establishing the formulation for both delay and jitter. Furthermore, we evaluate the effect of end-to-end delay and jitter in SDN networks as QoS metrics to finally establish their respective behavior.
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paper_title: Extension of OpenFlow protocol to support optical transport network, and its implementation

paper_content:

By having the OpenFlow protocol support Optical Transport Networks (OTN) and work as the unified control interface for multilayer (L0-L4) networks, a simple and cost-effective multilayer Software Defined Networking (SDN) controller can be created. Our aim is to propose and standardize the extended OpenFlow protocol to support OTN in Open Networking Foundation (ONF). We describe the approved specification, and the process from proposal to standard. We applied this extension to our OpenFlow controller and OpenFlow agent and succeeded in demonstrating that the extension works as desired in single- and multi-vendor environments. Future directions for OpenFlow extension and modeling of multilayer integrated nodes are also discussed.
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paper_title: An SDN based fully distributed NAT traversal scheme for IoT global connectivity

paper_content:

Existing NAT solves to IP address exhaustion problem binding private IP address and public IP address, and NAT traversal such as hole punching scheme enables to communicate End-to-End devices located in different private networks. However, such technologies are centralized the workload at NAT gateway and increase transmission delay caused by packet modification per packet. In this paper, we propose an SDN based fully distributed NAT traversal scheme, which can distribute the workload of NAT processing to devices and reduce transmission delay by packet switching instead of packet modification. Furthermore, we describe SDN based IoT connectivity management architecture for supporting IoT global connectivity and enhanced real-time and security.
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paper_title: Design and evaluation of a low-cost, DIY-inspired, underwater platform to promote experimental research in UWSN

paper_content:

Underwater Acoustic Sensor Networks (UWSN) is challenging research area due to limited bandwidth, low data rate, severe multipath, and high variability in the channel conditions. These complicated and non-linear channel characteristics render incorrect most simplifying assumptions used in simulations. We believe that, while researchers have proposed several novel protocols, their use of models and simulations as the only form of validation and intra-protocol comparison remains removed from reality. We argue that research experimentation is hindered by two fundamental constraints: high cost of underwater networking experiments, and lack of a single, easily-replicable platform for evaluation. We present here Underwater Platform to Promote Experimental Research (UPPER): a low-cost and flexible underwater platform designed to enable cost-effective and repeatable experimentation. We utilize commercial off-the-shelf (COTS) components to provide a HW/SW integrated solution that interfaces to two version of our custom hydrophones, from laptops that act as an Software-Defined Radio (SDR)-based physical layer, while allowing higher layer protocols to interact via a flexible API. With a total cost of $25 and $65 for each version of our underwater communication platform, we evaluate the platforms to demonstrate their data rates (50-600bps) and range (5-10m for v1, 30-50m for v2), thus indicating a cost-range tradeoff. We believe our platform removes the barrier to validating simulation results in underwater environments while also allowing a fair comparison between protocols.
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paper_title: Coralcon: An open source low-cost modem for underwater IoT applications

paper_content:

Most underwater deployments rely on acoustics for enabling communication. The equipment for underwater communication is usually very expensive. Simulations of underwater systems are insufficient for many researchers. An open source platform built with commercially available hardware at low rates along with customizable software modules may prove to be very useful for researcher. This paper particularly focuses on the details of Coralcon, a low-cost, open-sources based modem designed to be integrated with underwater Internet of Things (IoT). We implemented Coralcon with a customizable minimal software defined radio (SDR). Coralcon can be interfaced with other equipment to send and receive data reliably at rates up to 1000 bits per sec with one antenna.
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paper_title: Real-time video transmission over different underwater wireless optical channels using a directly modulated 520 nm laser diode

paper_content:

We experimentally demonstrate high-quality real-time video streaming over an underwater wireless optical communication (UWOC) link up to 5 m distance using phase-shift keying (PSK) modulation and quadrature amplitude modulation (QAM) schemes. The communication system uses software defined platforms connected to a commercial TO-9 packaged pigtailed 520 nm directly modulated laser diode (LD) with 1.2 GHz bandwidth as the optical transmitter and an avalanche photodiode (APD) module as the receiver. To simulate various underwater channels, we perform laboratory experiments on clear, coastal, harbor I, and harbor II ocean water types. The measured bit error rates of the received video streams are 1.0 × 10-9 for QPSK, 4-QAM, and 8-QAM and 9.9 × 10-9 for 8-PSK. We further evaluate the quality of the received live video images using structural similarity and achieve values of about 0.9 for the first three water types, and about 0.7 for harbor II. To the best of our knowledge, these results present the highest quality video streaming ever achieved in UWOC systems that resemble communication channels in real ocean water environments.
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paper_title: Software Defined Open Architecture Modem development at CMRE

paper_content:

This paper covers the first steps in creating a Software Defined Open Architecture Modem (SDOAM). Potentially useful operating environments, platforms and approaches are reviewed as well as relevant work on underwater digital communications at CMRE, including JANUS. A high-level architectural structure, based on a generalisation of the classic OSI communications stack, is proposed, identifying the modules that will make up the system and taking care to include all the features that the major stakeholders will want to see while minimising the investment that will need to be made to migrate from existing systems to SDOAMs. A key new element is the provision of policy engines that will negotiate the switching between different modules in the OSI-like layers. We also propose to formalise the cross-layer linking that is typically found in practical implementations by providing a fully-connected cross-layer framework for all processes to access. Finally, future developments and research directions are identified. The exact definitions of the interfaces between these modules remain to be specified, as is the software support environment on which they will operate.
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paper_title: Internet of underwater things: Challenges and routing protocols

paper_content:

The Internet of Underwater Things (IoUT) is a novel class of Internet of Things (IoT) that enables practical applications toward developing smart cities. Underwater Wireless Sensor Network (UWSN) shows great potential for the future but also poses new challenges for IoUT. In addition, routing protocol will play a major role in handling how to forward data among the substantial number of things“. In this paper, we call attention to the challenges for IoUT, provide an exhaustive investigation of cutting-edge routing protocol and find the connection between the challenges and routing protocols for IoUT.
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paper_title: Software-defined underwater acoustic networks: toward a high-rate real-time reconfigurable modem

paper_content:

We review and discuss the challenges of adopting software-defined radio principles in underwater acoustic networks, and propose a software-defined acoustic modem prototype based on commercial off-the-shelf components. We first review current SDR-based architectures for underwater acoustic communications. Then we describe the architecture of a new software-defined acoustic modem prototype, and provide performance evaluation results in both indoor (water tank) and outdoor (lake) environments. We present three experimental testbed scenarios that demonstrate the real-time reconfigurable capabilities of the proposed prototype and show that it exhibits favorable characteristics toward spectrally efficient cognitive underwater networks, and high data rate underwater acoustic links. Finally, we discuss open research challenges for the implementation of next-generation software-defined underwater acoustic networks.
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paper_title: Bitwise ranging through underwater acoustic communication with frequency hopped FSK utilizing the Goertzel algorithm

paper_content:

Acoustic communication is the most common technique to communicate with an autonomous underwater vehicle (AUV) during its mission. Furthermore, this communication channel is often used for ranging, to support the navigation of the vehicle and localize it in world coordinates, whereas the vehicles dead reckoning only gives a relative position to a starting point. Due to the severe multipath propagation under water, frequency hopped frequency shift keying (FH-FSK) is often used underwater to communicate over long ranges, whereas it can be otherwise deemed bandwidth inefficient. In this work, a version of FH-FSK is realized as a software defined radio (SDR) on a system on chip, that is connected to the peripherals necessary to transmit and receive signals via acoustic transducers. Besides the communication capabilities, we demonstrate the application of this modulation scheme to ranging for each transmitted data bit.
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paper_title: Software-defined underwater acoustic networking platform and its applications

paper_content:

As underwater communications adopt acoustics as the primary modality, we are confronting several unique challenges such as highly limited bandwidth, severe fading, and long propagation delay. To cope with these, many MAC protocols and PHY layer techniques have been proposed. In this paper, we present a research platform that allows developers to easily implement and compare their protocols in an underwater network and configure them at runtime. We have built our platform using widely supported software that has been successfully used in terrestrial radio and network development. The flexibility of development tools such as software defined radio, TinyOS, and Linux have provided the ability for rapid growth in the community. Our platform adapts some of these tools to work well with the underwater environment while maintaining flexibility, ultimately providing an end-to-end networking approach for underwater acoustic development. To show its applicability, we further implement and evaluate channel allocation and time synchronization protocols on our platform.
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paper_title: The design and experiment of a software-defined acoustic modem for underwater sensor network

paper_content:

In this paper, the design scheme and system implementation of a compact, low-cost, energy-efficient, real-time, software-defined acoustic (SDA) modem for underwater sensor network are described. The hardware and software performance of the SDA modem are presented by the underwater experiment results of different underwater communication and networking method using the same modem.
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paper_title: Software defined radio (SDR) foundations, technology tradeoffs: A survey

paper_content:

Software radio has emerged as a focus of both academic research and commercial development for future wireless systems. This paper briefly reviews the foundation concepts of the Software Radio. It then characterizes the tradeoffs among core software-radio technologies. Object oriented analysis leads to the definition of the radio reference platform and the related layered object-oriented architecture supporting simultaneous hardware and software evolution. Research issues include layering, tunneling, virtual machines and intelligent agents.
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paper_title: Methods of Hybrid Cognitive Radio Network: A Survey

paper_content:

In advanced radio communication systems, most of the radio spectrum remains underutilized. To fully utilize the radio spectrum, an efficient allocation of the scarce and expensive radio resources is most important and challenging. As a solution of this problem, cognitive radio network (CRN) can make better use of the radio spectrum by allowing the secondary users (SU) to opportunistically access and share the licensed spectrum using dynamic spectrum access (DSA) technology. There are two main sharing techniques in CRN based on the access technology: 1) over-lay; 2) under-lay. In over-lay mode, secondary user can access only vacant spectrum in the absence of primary user (PU) but in underlay mode, the SUs can coexist with the PUs in the same channel under the SINR (signal to interference plus noise ratio) constraints. To further improve the spectrum scarcity, both over-lay and under-lay approaches gets combined under SINR constraints to make a hybrid cognitive radio. In this paper, we provide a survey for different methods of hybrid cognitive radio in which under-lay and over-lay modes are merged using different techniques to efficiently utilize the scarce radio spectrum.
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paper_title: Dolphins First: Dolphin-Aware Communications in Multi-Hop Underwater Cognitive Acoustic Networks

paper_content:

Acoustic communication is the most versatile and widely used technology for underwater wireless networks. However, the frequencies used by current acoustic modems are heavily overlapped with the cetacean communication frequencies, where the man-made noise of underwater acoustic communications may have harmful or even fatal impact on those lovely marine mammals, e.g., dolphins. To pursue the environmental friendly design for sustainable underwater monitoring and exploration, specifically, to avoid the man-made interference to dolphins, in this paper, we propose a cognitive acoustic transmission scheme, called dolphin-aware data transmission (DAD-Tx), in multi-hop underwater acoustic networks. Different from the collaborative sensing approach and the simplified modeling of dolphins’ activities in existing literature, we employ a probabilistic method to capture the stochastic characteristics of dolphins’ communications, and mathematically describe the dolphin-aware constraint. Under dolphin-awareness and wireless acoustic transmission constraints, we further formulate the DAD-Tx optimization problem aiming to maximize the end-to-end throughput. Since the formulated problem contains probabilistic constraint and is NP-hard, we leverage Bernstein approximation and develop a three-phase solution procedure with heuristic algorithms for feasible solutions. Simulation results show the effectiveness of the proposed scheme in terms of both network performance and dolphin awareness.
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paper_title: Frequency offset estimation for index modulation-based cognitive underwater acoustic communications

paper_content:

As a manner of communications with the high spectral and energy efficiency, cognitive underwater acoustic communications based on index modulation (CUAC-IM) have been investigating by us in more recent years. Like other communication system, estimation algorithm on frequency offset (FO) caused by the relative motion of mobile station is crucial to CUAC-IM system. In this paper, system model, especially for applications of index modulation in cognitive underwater acoustic communications, will be presented firstly. Then, an estimation method on the FO over the above model will be proposed, which employs the high order statistics. Finally, computer simulation will be performed to verify the aforementioned solution of the FO. Simulation results demonstrate that the suggested algorithm is accurate and efficient.
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paper_title: Research on Dynamic Spectrum Allocation Using Cognitive Radio Technologies

paper_content:

With the fast development of wireless communication technologies and the amazing increasing of user numbers in Internet of Things,the limited spectrum resources have become more and more scarce.However,today's spectrum resources are regulated by a fixed assignment policy and they are in inefficient usage.How to satisfy users' high mobility and mass date transmission requirements are new challenges.Cognitive Radio is one of these technologies that can offer users a seamless accessing environment,and solves the current spectrum inefficiency problems.It represents a great potential for the development of Internet of Things.In this paper,using Cognitive Radio technologies,we propose a cognitive radio users and networks cooperative spectrum allocation framework,then propose a dynamic spectrum allocation solution.This solution consists of two algorithms: One is a Spectrum Ranking Selecting algorithm(SRS) implemented at cognitive radio users,to meet their QoS and mobility requirements;and the other is a Joint Optimization Matching algorithm(JOM) implemented at the networks,by achieving the co-optimization between spectrum utilization and handoff rate to satisfy the mass data transmission requirement.With the cooperation between cognitive radio users and networks,our solution can construct an efficient dynamic spectrum allocation.Simulation results show that,compared with the traditional mapping algorithm,our solution can significantly improve the performance of networks in terms of throughput by 70% and spectrum handoff rate by 56%.
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paper_title: OFDM-based spectrum-aware routing in underwater cognitive acoustic networks

paper_content:

With the long propagation delay of an acoustic signal in underwater communications systems, relay node selection is one of the key design factors, because it significantly improves end-to-end delay, thereby improving overall network performance. To this end, the authors propose orthogonal frequency division multiplexing-based spectrum-aware routing (OSAR), a scheme in which spectrum sensing is done by an energy detector, and each sensor node broadcasts its local sensing results to all one-hop nodes via an extended beacon message. Each sensor node then selects nodes that agree on an idle channel, consequentially forming a set of neighbouring nodes. The selection of a relay node is determined by calculating the transmission delay – the source/relay node selected is the one that has the minimum transmission delay from among all nodes in the neighbouring set. To evaluate OSAR, the authors perform extensive simulations via ns-MIRACLE for different numbers of channels using a BELLHOP model, and evaluate the average delay for different sensor nodes within the considered network. The results show a substantial decrease in delay as the number of sensor nodes increases in the network. In addition, the authors verify that the packet delivery ratio increases with increases in the number of sensor nodes, and prove better performance in the overhead ratio. The authors' simulation results verify that OSAR outperforms existing solutions.
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paper_title: On Rethinking Cognitive Access for Underwater Acoustic Communications

paper_content:

In this paper, we investigate how to reformulate the concepts of cognitive access, originally developed for radio communications, in the framework of underwater acoustic communications. A straightforward application of the classical energy-detection-based cognitive approach, such as the one employed for radio communications, would result in a reduced spectrum utilization in an acoustic scenario. Actually, in the underwater scenario, acoustic signals sensed by a network node are likely to be due to communication sources as well as natural/artificial acoustic sources (e.g., mammals, ship engines, and so forth), differently from classical cognitive radio access, where each signal at the receiver is generated by a communication source. To maximize the access probability for cognitive acoustic nodes, we focus on understanding the nature of sensed interference. Toward this aim, we try to discriminate among natural and communications sources by classifying the images representing the time and frequency features of the received signals, obtained by means of the Wigner–Ville transform. Two different classifiers are considered here. The first one is targeted on finding natural interference while the second one looks for communication. Simulation results show how the herein described approach drastically enhances the access probability in an acoustic scenario with respect to a direct rephrasing of classical cognitive access. A possible protocol for implementing cognitive access is also described and its performance evaluated.
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paper_title: Localization, routing and its security in UWSN — A survey

paper_content:

Underwater sensor networks are promising apparatus for the discovery of the ocean. For localization and networking protocol, this sensor network requires new robust solution. For terrestrial sensor network various localization algorithms and routing protocols have been proposed, there are very few localization and routing techniques for UWSN. Compare to terrestrial sensor network the features of underwater sensor network are basically different. Underwater acoustic communication is described by stringent physical layer condition with severe bandwidth restrictions. In underwater the uneven rate of sound and the long propagation delay create a distinct set of challenges for localization and routing in UWSN. This paper surveyed the different localization and routing schemes that are applicable to underwater sensor networks, the dispute in meeting the condition created by rising function for such network, attacks, security requirement in UWSN and localization and routing security in UWSN.
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paper_title: A review on recent advances in spectrum sensing, energy efficiency and security threats in cognitive radio network

paper_content:

In the last decade there is a vast development in the wireless communication and new wireless devices so the demand of the radio spectrum is increasing, There is a need of efficient spectrum utilization because due to fixed assignment policy a huge portion of licensed spectrum is underutilized. To exploit the radio spectrum in a more intelligent and flexible way, regulatory bodies are reviewing their policies by adopting innovative communication technology. Cognitive Radio is a revolutionary technology which enables access to underutilized spectrum efficiently and dynamically without causing interference to the licensed users. In the last few years there has been significant development in cognitive radio technology. This paper reviews recent development and advances in three key areas of cognitive radio network — spectrum sensing, security and energy efficiency. In this paper the fundamentals of cognitive radio is first discussed and than existing work is reviewed.
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paper_title: Joint Relay Selection and Power Allocation in Underwater Cognitive Acoustic Cooperative System with Limited Feedback

paper_content:

We study the problem of joint relay selection and power allocation in a underwater cooperative system with multiple users assisted by multiple relays. Due to the harsh underwater environments, the channel state information (CSI) at the transmitter is imperfect, which leads to the performance degrading in the underwater cooperative acoustic system. Therefore, we analyze the cooperative underwater acoustic channel with limited feedback to increase the sum-rate of the system. Meanwhile, different from other researches, we do not only focus on the single system scenario, but also consider the presence of nearby acoustic activities and the problem of joint relay selection and power allocation is solved in a cognitive acoustic (CA) scenario. Thus the codebook of interference CSI and the codebook of quantized relay selection and power allocation strategy are designed, respectively. Simulation results show that a few bits feedback can significantly improve the performance of the CA cooperative acoustic system.
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paper_title: Receiver-Initiated Spectrum Management for Underwater Cognitive Acoustic Network

paper_content:

Cognitive acoustic (CA) is emerging as a promising technique for environment-friendly and spectrum-efficient underwater communications. Due to the unique features of underwater acoustic networks (UANs), traditional spectrum management systems designed for cognitive radio (CR) need an overhaul to work efficiently in underwater environments. In this paper, we propose a receiver-initiated spectrum management (RISM) system for underwater cognitive acoustic networks (UCANs). RISM seeks to improve the performance of UCANs through a collaboration of physical layer and medium access control (MAC) layer. It aims to provide efficient spectrum utilization and data transmissions with a small collision probability for CA nodes, while avoiding harmful interference with both “natural acoustic systems”, such as marine mammals, and “artificial acoustic systems”, like sonars and other UCANs. In addition, to solve the unique challenge of deciding when receivers start to retrieve data from their neighbors, we propose to use a traffic predictor on each receiver to forecast the traffic loads on surrounding nodes. This allows each receiver to dynamically adjust its polling frequency according to the variation of a network traffic. Simulation results show that the performance of RISM with smart polling scheme outperforms the conventional sender-initiated approach in terms of throughput, hop-by-hop delay, and energy efficiency.
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paper_title: Full Spectrum Sharing in Cognitive Radio Networks Toward 5G: A Survey

paper_content:

With the development of wireless communication technology, the need for bandwidth is increasing continuously, and the growing need makes wireless spectrum resources more and more scarce. Cognitive radio (CR) has been identified as a promising solution for the spectrum scarcity, and its core idea is the dynamic spectrum access. It can dynamically utilize the idle spectrum without affecting the rights of primary users, so that multiple services or users can share a part of the spectrum, thus achieving the goal of avoiding the high cost of spectrum resetting and improving the utilization of spectrum resources. In order to meet the critical requirements of the fifth generation (5G) mobile network, especially the Wider-Coverage , Massive-Capacity , Massive-Connectivity , and Low-Latency four application scenarios, the spectrum range used in 5G will be further expanded into the full spectrum era, possibly from 1 GHz to 100 GHz. In this paper, we conduct a comprehensive survey of CR technology and focus on the current significant research progress in the full spectrum sharing towards the four scenarios. In addition, the key enabling technologies that may be closely related to the study of 5G in the near future are presented in terms of full-duplex spectrum sensing, spectrum-database based spectrum sensing, auction based spectrum allocation, carrier aggregation based spectrum access. Subsequently, other issues that play a positive role for the development research and practical application of CR, such as common control channel, energy harvesting, non-orthogonal multiple access, and CR based aeronautical communication are discussed. The comprehensive overview provided by this survey is expected to help researchers develop CR technology in the field of 5G further.
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paper_title: Cognitive Routing in Software-Defined Underwater Acoustic Networks

paper_content:

There are two different types of primary users (natural acoustic and artificial acoustic), and there is a long propagation delay for acoustic links in underwater cognitive acoustic networks (UCANs). Thus, the selection of a stable route is one of the key design factors for improving overall network stability, thereby reducing end-to-end delay. Software-defined networking (SDN) is a novel approach that improves network intelligence. To this end, we propose a novel SDN-based routing protocol for UCANs in order to find a stable route between source and destination. A main controller is placed in a surface buoy that is responsible for the global view of the network, whereas local controllers are placed in different autonomous underwater vehicles (AUVs) that are responsible for a localized view of the network. The AUVs have fixed trajectories, and sensor nodes within transmission range of the AUVs serve as gateways to relay the gathered information to the controllers. This is an SDN-based underwater communications scheme whereby two nodes can only communicate when they have a consensus about a common idle channel. To evaluate our proposed scheme, we perform extensive simulations and improve network performance in terms of end-to-end delay, delivery ratio, and overhead.
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paper_title: Design of underwater acoustic sensor communication systems based on software-defined networks in big data

paper_content:

The application based on big data is an important development trend of underwater acoustic sensor networks. However, traditional underwater acoustic sensor networks rely on the hardware infrastructure. The flexibility and scalability cannot be satisfied greatly. Due to the low performance of underwater acoustic sensor networks, it creates significant barriers to the implementation of big data. Software-defined network is regarded as a new infrastructure of next-generation network. It offers a novel solution for designing underwater acoustic sensor networks of high performance. In this article, a software-defined network–based solution is proposed to build the architecture of underwater acoustic sensor networks in big data. The design procedures of the data plane and control plane are described in detail. In the data plane, the works include the hardware design of OpenFlow-based virtual switch and the design of the physical layer based on software-defined radio. The hierarchical clustering technology and t...
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paper_title: An SDN architecture for under water search and surveillance

paper_content:

Underwater Wireless Networking (UWN) schemes and applications have been attracting considerable interest with both industry and the research community. The nature of water, as a carrier medium, imposes very significant constraints on the both the characteristics and information carrying capacity of underwater communication channels. Currently, acoustic and optical are the two main physical platform/channel choices. Acoustics offers relative simplicity but low data rates. Optical has a considerable bandwidth advantage, but is much more complex to implement, exploit and manage. Leveraging both technologies enables exploitation of their complementarities and synergies. A Software Defined Networking architecture, which separates the control and data planes, enables full exploitation of this acousto-optic combination. In this configuration, the longer-ranged acoustic channel serves as the control plane, allowing the controller to issue mobility and network related commands to distant AUVs, whilst the shorter range (but higher throughput) optical channel serves as the data plane, thereby allowing for fast transfer of data. This paper presents such a system, employing the NATO approved JANUS underwater communications standard for the control channel.
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paper_title: SoftWater: Software-defined networking for next-generation underwater communication systems

paper_content:

Abstract Underwater communication systems have drawn the attention of the research community in the last 15 years. This growing interest can largely be attributed to new civil and military applications enabled by large-scale networks of underwater devices (e.g., underwater static sensors, unmanned autonomous vehicles (AUVs), and autonomous robots), which can retrieve information from the aquatic and marine environment, perform in-network processing on the extracted data, and transmit the collected information to remote locations. Currently underwater communication systems are inherently hardware-based and rely on closed and inflexible architectural design. This imposes significant challenges into adopting new underwater communication and networking technologies, prevent the provision of truly-differentiated services to highly diverse underwater applications, and induce great barriers to integrate heterogeneous underwater devices. Software-defined networking (SDN), recognized as the next-generation networking paradigm, relies on the highly flexible, programmable, and virtualizable network architecture to dramatically improve network resource utilization, simplify network management, reduce operating cost, and promote innovation and evolution. In this paper, a software-defined architecture, namely SoftWater, is first introduced to facilitate the development of the next-generation underwater communication systems. More specifically, by exploiting the network function virtualization (NFV) and network virtualization concepts, SoftWater architecture can easily incorporate new underwater communication solutions, accordingly maximize the network capacity, can achieve the network robustness and energy efficiency, as well as can provide truly differentiated and scalable networking services. Consequently, the SoftWater architecture can simultaneously support a variety of different underwater applications, and can enable the interoperability of underwater devices from different manufacturers that operate on different underwater communication technologies based on acoustic, optical, or radio waves. Moreover, the essential network management tools of SoftWater are discussed, including reconfigurable multi-controller placement, hybrid in-band and out-of-band control traffic balancing, and utility-optimal network virtualization. Furthermore, the major benefits of SoftWater architecture are demonstrated by introducing software-defined underwater networking solutions, including the throughput-optimal underwater routing, SDN-enhanced fault recovery, and software-defined underwater mobility management. The research challenges to realize the SoftWater are also discussed in detail.
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paper_title: Design and Implementation of SDN-Based Underwater Acoustic Sensor Networks With Multi-Controllers

paper_content:

Underwater acoustic sensor networks (UASNs) provide new opportunities for exploring oceans and consequently improving our understanding of the underwater world. UASNs usually rely on hardware infrastructure with poor flexibility and versatility. Compared with wireless sensor networks, UASNs are quite expensive to manufacture and deploy. Due to the unique data format, protocols, and service constraints of various applications, UASNs are typically deployed in a redundant manner, which not only leads to waste but also causes serious interference due to the presence of multiple signals in the same underwater region. Software-defined networking (SDN) provides an innovative means of improving the flexibility of underwater systems. In this paper, we present an SDN-based UASN framework, followed by the design of a clustering method in which learning automata and degree-constrained connected dominating sets are employed. We then propose a load balancing mechanism involving multiple controllers, based on the consistent hashing algorithm. Finally, we describe a simulation program (called UASNs hypervisor) that we developed and implemented to assess the network survival time, bit-error rate, and computational complexity. The experimental results show that the UASN was improved significantly. This work provides important theoretical and technical support for the implementation of SDN-based UASNs.
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paper_title: Convex optimization–based multi-user detection in underwater acoustic sensor networks

paper_content:

Multi-carrier code-division multiple access is an important technical means for high-performance underwater acoustic sensor networks. Nevertheless, severe multiple access interference is a huge cha...
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paper_title: Toward the Development of Secure Underwater Acoustic Networks

paper_content:

Underwater acoustic networks (UANs) have been recognized as an enabling technology for various applications in the maritime domain. The wireless nature of the acoustic medium makes UANs vulnerable to various malicious attacks, yet, limited consideration has been given to security challenges. In this paper, we outline a hybrid architecture that incorporates aspects of physical layer security, software defined networking, node cooperation, cross-layering, context-awareness, and cognition. The proposed architecture envisions strategies at the node as well as at the network level that adapt to environmental changes, the status of the network and the possible array of attacks. Several examples of attacks and countermeasures are discussed while deployment and functionality issues of the proposed architecture are taken into consideration. This work is not intended to represent a whatsoever proven solution but mainly to suggest future research directions to the scientific community working in the area of UANs.
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paper_title: WaterCOM: An Architecture Model of Context-Oriented Middleware

paper_content:

Integrating physical and information space into applications increases application's complexity and development difficulty. In Ubiquitous environment, context collection, aggregation and notification raise complex scientific problems and new challenges. In this paper we address these challenges by proposing a conceptual context-oriented middleware architecture. We first discuss the reason to use context in ubiquitous computing, and context-oriented middleware requirements. Then we present our approach by describing a service-oriented architecture model. It provides a dynamic adaptation ability, supports multiple context models and multi-domain context consumer. Finally, we discuss the benefit of our conceptual approach by describing and comparing current context middlewares.
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paper_title: Improving energy efficiency performance of ALOHA based underwater acoustic sensor networks

paper_content:

The goal of this paper is to explore the throughput and energy efficiency of ALOHA based underwater acoustic sensor networks (UASNs). Primarily, we frame analytical expressions for the throughput and energy efficiency of UW-ALOHA for single hop UASN. We then procure closed form expression for the optimal channel attempt rates that maximize energy efficiency and throughput Independently. In this case, we notice that the attempt rate that maximizes the energy efficiency leads to drop in the network throughput and vice versa. We then consider a cross layer energy optimization problem with the objective of maximizing the energy efficiency of the network while meeting an SNR constraint at the PHY layer and a throughput constraint at the MAC layer. We also consider underwater acoustic channel specific parameters like distance dependent bandwidth and spreading losses for the analysis. Using Karush-Kuhn Tucker conditions, we derive closed form solution for the optimal channel attempt rates that meet the desired objectives. Extensive performance evaluation results show that sensible selection of the attempt rates by the sensor nodes can improve the energy efficiency of the network significantly.
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paper_title: A SDN-controlled underwater MAC and routing testbed

paper_content:

Efficient data communication among autonomous under-water vehicles (AUVs) is difficult. Challenges include the long propagation delays arising with acoustic communication solutions, and line-of-sight requirements for optical transceivers. Existing multi-hop routing approaches are not always appropriate due to node mobility. This work presents a centralized approach to network control, exploiting the observation that AUV networks will have a bounded number of nodes. The paper describes a SDN realization of AUV networking, and documents the implementation of a small-scale replica of the system in our testbed, which can be accessed remotely via a web page and SSH. We then demonstrate the functionality of our implementation by evaluating the performances of two existing MAC protocols namely Slotted FAMA [11] and UW-Aloha [13], in a multi-hop, underwater scenario.
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paper_title: C-MAC: A TDMA-Based MAC Protocol for Underwater Acoustic Sensor Networks

paper_content:

Different from terrestrial wireless networks that use radio channel, underwater networks utilize acoustic channel, which poses great research challenges in medium access control (MAC) protocol design due to its low available bandwidth and high propagation delay characteristics. In addition, the high bit-error, high transmission energy cost, and complex multi-path effects in underwater environment make it even harder. In this paper, a suitable MAC protocol, named C-MAC (cellular MAC) for underwater acoustic sensor networks (UWANs) is proposed. C-MAC is a TDMA-based MAC protocol, which divides networks into many cells. Each cell is distributed a time slot; nodes in a cell, can only transmit packets in the cell’s time slot. Experiments show the protocol can avoid collision, minimize the energy consumption, and increase the throughput efficiency.
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paper_title: Software-defined underwater acoustic networking platform

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Currently acoustics is the primary modality for underwater communication even though it presents a difficult channel. To try and cope with the challenges of the channel many MAC protocols and PHY layer techniques have been proposed. In this paper we present a research platform that allows developers to easily implement and compare their protocols in an underwater network and configure them at runtime. We have built our platform using widely supported software that has been successfully used in terrestrial radio and network development. The flexibility of development tools such as software defined radio have provided the ability for rapid growth in the community. Our platform adapts some of these tools to work well with the underwater environment while maintaining flexibility, ultimately providing an end-to-end networking approach for underwater acoustic development.
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paper_title: Shallow water acoustic channel modeling and MIMO-OFDM simulations

paper_content:

The uniqueness of underwater acoustic (UWA) channel and features like limited bandwidth, multipath spread, severe Doppler Effect and transmission loss make the UWA communication more challenging and intricate. The use of multiple inputs multiple outputs (MIMO) increases the spatial diversity of the system and the bandwidth limitation issue is solved by Orthogonal Frequency Division Multiplexing (OFDM) due to its high spectral efficiency, whereas attenuation coefficient plays a key role in determining the transmission loss. UWA Channel capacity is highly influenced by the transducer spacing and the delay spread. A simple and brief MIMO UWA communication model is presented here to measure the transmission loss by analyzing different models, the spatial coherence by analyzing the effect of spacing between transducers, ambient noise effect, multipath effect and consequently increase the spatial diversity and spectral efficiency by using MIMO and OFDM for shallow water communication. The ambient noise effects are found using Wenz' model whereas three different models; Thorp's, Fisher & Simmons'(F&S) and Francois & Garrison's (F&G) models are analyzed and compared to find the attenuation coefficient of the acoustic signal. Multipath propagation of the signal is considered following the Ray Theory and a model proposed by Bouvet & Loussert is used to find multipath effect. Finally, the modeled underwater channels are used to simulate and analyze the performance of MIMO-OFDM communication.
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paper_title: Remotely operated underwater vehicle with surveillance system

paper_content:

Remotely operated underwater vehicles or ROVs are underwater robots that are used in science, entertainment, military and offshore oil industries. Their main function is to interact with the environment under the water in various ways. It is a very complicated system and uncommon in the developing or the underdeveloped countries around the world. Countries consisting many water bodies and prone to maritime incidents ROVs can be very useful in rescue missions. In this research work we built a ROV and equipped it with a surveillance system. Our ROV will be quite useful beside rescuers by monitoring the underwater and sending the video. It can also be used in military, scientific research, film making under the water and monitoring underwater industrial structures and underwater network devices.
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paper_title: Network Function Virtualization: State-of-the-art and Research Challenges

paper_content:

Network function virtualization (NFV) has drawn significant attention from both industry and academia as an important shift in telecommunication service provisioning. By decoupling network functions (NFs) from the physical devices on which they run, NFV has the potential to lead to significant reductions in operating expenses (OPEX) and capital expenses (CAPEX) and facilitate the deployment of new services with increased agility and faster time-to-value. The NFV paradigm is still in its infancy and there is a large spectrum of opportunities for the research community to develop new architectures, systems and applications, and to evaluate alternatives and trade-offs in developing technologies for its successful deployment. In this paper, after discussing NFV and its relationship with complementary fields of software defined networking (SDN) and cloud computing, we survey the state-of-the-art in NFV, and identify promising research directions in this area. We also overview key NFV projects, standardization efforts, early implementations, use cases, and commercial products.
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paper_title: Multiple-Input Multiple-Output Technique for Underwater Acoustic Communication System

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The performance of an underwater acoustic communication (UAC) system is limited due to tough propagation conditions in the UAC channel. Multiple-Input Multiple-Output (MIMO) technique can improve the reliability of the data transmission system, increase its speed, increase its range, and reduce the energy consumption. The paper presents an implementation method of MIMO technique in the form of coding the Space-Time Block Code and its optimal case in the form of Alamouti coding. The results of simulation tests in a channel with flat Rayleigh fading were included, which were compared with the quality of the SISO system.
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paper_title: GENI with a Network Processing Unit: Enriching SDN Application Experiments

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This paper reports the integration of Dell's specialized split data plane (SDP) OpenFlow switch into the GENI testbed. In addition, the paper outlines the research directions in network science and engineering that such a switch may enable together with a new perspective on education in network programming. An SDP switch can be used to perform some specialized processing on flows with special hardware accelerators in addition to hosting any application (running on a Linux OS) that a user may insert on the path of a flow. The SDP switch is composed of a Dell switch (PowerConnect 7024) with an internal physical connection to a sub-unit, Network Processor Unit (NPU), by Cavium Networks. Hosting an OpenvSwitch on the NPU with open hosting of Linux applications enables software-defined networking experiments. The integration challenges/process associated with this unit is presented as a future reference to other such foreign box integrations.
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paper_title: Adaptive combining multi-branch frequency-domain detector for underwater acoustic cooperative communication

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In this paper, we propose an adaptive combining multi-branch frequency-domain detector (ACMFD) for amplify-and-forward (AF) underwater acoustic cooperative communication. In contrast to the existing methods, the proposed detector can adaptively combine the received signals from different nodes at destination, and don't need the assumption that full and perfect channel state information (CSI) of all the relayed paths at the receiver is known. Simulation results show that the proposed ACMFD has better performance than existing counterparts.
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paper_title: Minimization of flow table for TCAM based openflow switches by virtual compression approach

paper_content:

Forwarding lookup in the open flow switch can be done for each arriving packet by every switch in path. Every switch maintains a set of IP prefix value in its lookup table. For a given IP address it finds a longest prefix match in the forwarding table that matches first fewer bits of destination address. Earlier, there are several technique that has been proposed to optimize the table space and to reduce the number of entries in the forwarding table. In TCAM prefix values needs to be stored in descending order of its length, it require more number of entries needs to be shifted. In this paper we propose a method to reduce the length of the prefix value up to 50 to 60% horizontally as well as vertically which will be stored in the forwarding table. It involves significant prefix methods to reduce number of entries in the forwarding table.
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paper_title: TCAM-based flow lookup design on FPGA and its applications

paper_content:

TCAM is now emulated using FPGAs and based on memory known as RAM or register. Most of them are made just using register- or RAM-based resource individually when mapped to FPGA hardware. This paper presents a 4×4 flexible Basic-TCAM architecture that can be flexibly designed based selectively on memory-based or register-based FPGA resource or both of them in combined manner. In addition, it can also allow a scalable architecture. A wider and deeper TCAM of size 512×36 built based on it seizes only 73,728 bits and 1,503 logic utilization and supports competitive search latency of 1 clock cycle over Altera Cyclone V FPGA. A typical flow lookup design based on this Basic-TCAM architecture uses a TCAM of size 4×16 and a simple parser to do a flow lookup. This design application is then taken place in a simple VLAN-based switch system for further feasible application of the TCAM in this work.
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paper_title: BER performance of underwater multiuser cooperative communication based on MMSE-DFD algorithm

paper_content:

An underwater multiuser cooperative communication system based on minimum mean-square error decision feedback detection (MMSE-DFD) algorithm is proposed, where communication between two source nodes and one destination node is assumed. In this paper, underwater acoustic (UWA) channel is modeled as a sparse multipath channel experiencing Rayleigh fading. Compared with the traditional multiuser cooperative communication, the proposed communication system is able to increase the throughput of the communication system, when the half-duplex mode is assumed. Furthermore, computer simulations and analyses show that through the time diversity obtained by the cooperative system, the spatial diversity provided by the transducer array at the destination node and the MMSE-DFD algorithm, the proposed communication system exhibits better BER performance than the traditional cooperative system.
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paper_title: Coordinated anti-collision transmission with parity grouping for multi-hop underwater acoustic cooperative networks

paper_content:

Due to the low speed of underwater acoustic propagation and the adverse energy supply of underwater facility, it is a challenging task to reduce the end-to-end delay and the system energy consumption. In this paper, an improved scheme is proposed based on multi-hop coordinated transmission for underwater acoustic cooperative networks. The data packets are divided into parity groups and then transferred, where the odd-numbered node transfers the odd-numbered packet and the even-numbered node transfers the even-numbered packet accordingly. Arbitrary node can be a cooperative relay for the adjacent two nodes. In the meanwhile, adopting a proper transfer power, arbitrary two nodes separated by four nodes can deliver data packets to the next node without collision. The simulation results show that the proposed scheme can effectively reduce the average end-to-end delay and energy consumption with the acceptable outage probability.
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paper_title: Software-Defined Network Function Virtualization: A Survey

paper_content:

Diverse proprietary network appliances increase both the capital and operational expense of service providers, meanwhile causing problems of network ossification. Network function virtualization (NFV) is proposed to address these issues by implementing network functions as pure software on commodity and general hardware. NFV allows flexible provisioning, deployment, and centralized management of virtual network functions. Integrated with SDN, the software-defined NFV architecture further offers agile traffic steering and joint optimization of network functions and resources. This architecture benefits a wide range of applications (e.g., service chaining) and is becoming the dominant form of NFV. In this survey, we present a thorough investigation of the development of NFV under the software-defined NFV architecture, with an emphasis on service chaining as its application. We first introduce the software-defined NFV architecture as the state of the art of NFV and present relationships between NFV and SDN. Then, we provide a historic view of the involvement from middlebox to NFV. Finally, we introduce significant challenges and relevant solutions of NFV, and discuss its future research directions by different application domains.
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paper_title: A study of applications, challenges, and channel models on the Internet of Underwater Things

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The Internet of Underwater Things (IoUT) is a novel class of Internet of Things (IoT), and one of the emerging technologies toward smart city. To support the concept of IoUT, Underwater Wireless Sensor Networks (UWSNs) have emerged as a promising system. In this paper, we survey the potential IoUT applications, point out the challenges and differences between UWSNs and traditional sensor networks, and investigate the channel models. We validated the models by simulations.
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paper_title: Development of advanced Lithium-ion battery for underwater vehicle

paper_content:

Electric power storage is an important technology for all equipments of underwater vehicles however environmental pressure is high, the temperature is 5 degrees Celsius or less, and conditions are unsuitable for many chemical reactions in the deep sea. Battery capacity is mainly dependent on its mass; this means that the cruising range of underwater vehicles is proportional to the mass of the battery. To solve this problem, a high energy density battery and its enclosures are being developed. Concretely, batteries are enclosed with oil, to equate environmental pressure and to be insulated in seawater. This is called the oil compensated method, and is applied to various batteries. The oil-filled 29Ah Lithium-Ion battery for the vehicle was developed in 2010. And sea trial was carried out equipped autonomous underwater vehicle “MR-X1”. The paper introduces Lithium-Ion secondary battery and result of sea trail.
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paper_title: An Acoustic Positioning Buoy

paper_content:

Real-time positioning for autonomous underwater vehicles (AUVs) is an important but very complex problem. This article documents the overall process of creating a buoy system for AUV positioning. Similar to Global Positioning System (GPS) electromagnetic signals, the buoys were designed to transmit acoustic signals. These signals would be received and processed by the AUV, allowing the AUV to position itself in real time. This is a system-level report and does not go into any great detail on advanced topics. This project was led by Dr. Harold (Bud) Vincent, a professor at the University of Rhode Island and an expert in underwater acoustics.
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paper_title: Performance analysis of self interference cancellation in bidirectional relaying underwater acoustic communication(BiRUAC) system

paper_content:

Due to the underwater acoustic channel is more complexity than the wireless communication channel. It has more multipath interference and larger attenuation, so the rate of transmission in the underwater acoustic channel is lower and the probability of error is larger. Aim to those problems, we proposed a bidirectional relaying underwater acoustic communication system and analysis the performance of this algorithm. The algorithm utilized the self interference cancellation model to remove the self interference. In the performance analysis part, we set the different size of self interference cancellation model. The simulations show that our proposed algorithm has lower SER and higher rate of transmission.
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paper_title: Research of EBAP algorithm for ad Hoc underwater acoustic network

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Ad Hoc underwater acoustic network have become a hot field in wireless sensor networks. Researches involving in sensor placement, network organization, localization, tracking and routing protocols, etc. Among these, routing protocol not only determines the monitoring quality of sensor network, but also acts as the foundation of network organization, sensor deployment and other applications. A fairly detailed description of the Ad Hoc underwater acoustic network protocol present in this paper. A good coverage, energy balancing and high connectivity routing algorithm (Energy Balancing based on AODV Protocol, EBAP) is designed according to the dynamic environment. A simulation program and performed field measurement is also developed. The result shows that EBAP can provide wireless communication in an Ad Hoc underwater acoustic network environment with low-latency and high-connectivity.
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paper_title: Underwater Acoustic Communication Using MIMO Hydrophone

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Hydrophone is a type of microphone that are used in underwater for recording and also for listening to the underwater sound. Generally, Hydrophones are based upon the transducer named Piezo electric that can convert the sound signals into an electrical signals. Here the frequencies associated with the underwater acoustic communications are 10Hz-IMHz. Frequencies above 1 MHz is rarely used but they can be easily absorbed in underwater. In Underwater wireless communication the information is transmitted through the channel named as UAC channel. This paper deals with the gain brought by using the underwater MIMO channel techniques.
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paper_title: Cross-Layer Balanced Relay Node Selection Algorithm for Opportunistic Routing in Underwater Ad-Hoc Networks

paper_content:

Due to the different transmission media, the underwater environment poses a more severe situation for routing algorithm design than that of the terrestrial environment. In this paper, we propose a weight based fuzzy logic (WBFL) relay node selection algorithm for the underwater Ad-hoc network, which can get the most balanced result than the previous algorithms without increasing the computation complexity. In this algorithm, the parameter scatters instead of the parameter values are inputted into the fuzzy logic inference system. By this innovation, the algorithm can take as much cross-layer parameters into account as possible during the relay node selection. Moreover, taking the node mobility into account, we propose a geographic based link lifetime prediction algorithm for underwater Ad-hoc network. The simulation results show that the WBFL algorithm can improve the network throughput at most 50% compare with the ExOR algorithm; moreover, the WBFL is effective and accurate on selecting relay nodes and the computation complexity is less than the previous algorithms.
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paper_title: Cross-Layer Design for Network Lifetime Maximization in Underwater Wireless Sensor Networks

paper_content:

This paper investigates the cross-layer design problem with the goal of maximizing the network lifetime for energy-constrained underwater wireless sensor networks (UWSNs). We first jointly consider link scheduling, transmission power and transmission rate in a proposed optimization problem with the adoption of time division multiple access (TDMA) schedules. Then, we propose an iterative algorithm to solve the optimization problem. It alternates between (1) link scheduling and (2) computation of transmission powers and transmission rates. In fact, the convergence of such iterative algorithm can be mathematically and empirically supported. We evaluate our algorithm for several network topologies. Extensive simulation results demonstrate the superiority of the proposed approach.
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paper_title: Cross-Layer Energy Minimization for Underwater ALOHA Networks

paper_content:

Underwater networks suffer from energy efficiency challenges due to difficulties in recharging underwater nodes. In addition, underwater acoustic networks show unique transmission characteristics such as frequency-dependent attenuation, which causes the transmission power to significantly depend on the bandwidth and the distance. We here investigate the cross-layer energy minimization problem in underwater ALOHA networks considering the unique transmission properties of the underwater medium. We first analyze the separate optimization of the physical (PHY) and multiple access control (MAC) layers to minimize energy consumption. We analytically obtain the energy-optimum channel access rate for the ALOHA MAC layer, which minimizes the energy consumption per successfully transmitted bit. We then formulate a cross-layer optimization problem, which jointly optimizes PHY and MAC layers to minimize energy consumption. We show that such cross-layer optimization reduces the energy consumption per bit as much as 66% in comparison with separate optimization of both layers. Cross-layer optimization achieves this energy efficiency by assigning higher MAC-layer resources to the nodes that have a longer distance to the base station, i.e., which experience a less efficient PHY layer. Moreover, cross-layer optimization significantly increases the amount data transferred until first node failure since it results in a more homogeneous energy consumption distribution among the nodes.
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paper_title: Fast Content Updating Algorithm for an SRAM-Based TCAM on FPGA

paper_content:

Static random-access memory (SRAM)-based ternary content-addressable memory (TCAM), an alternative to traditional TCAM, where inclusion of SRAM improves the memory access speed, scalability, cost, and storage density compared to conventional TCAM. In order to confidently use the SRAM-based TCAMs in application, an update module (UM) is essential. The UM replaces the old TCAM contents with fresh contents. This letter proposes a fast update mechanism for an SRAM-based TCAM and implements it on Xilinx Virtex-6 field-programmable gate array. To the best of authors’ knowledge, this is the first ever proposal on content-update-module in an SRAM-based TCAM, which consumes least possible clock cycles to update a TCAM word.
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paper_title: Load Balancing Mechanisms in the Software Defined Networks: A Systematic and Comprehensive Review of the Literature

paper_content:

With the expansion of the network and increasing their users, as well as emerging new technologies, such as cloud computing and big data, managing traditional networks is difficult. Therefore, it is necessary to change the traditional network architecture. Lately, to address this issue, a notion named software-defined network (SDN) has been proposed, which makes network management more conformable. Due to limited network resources and to meet the requirements of quality of service, one of the points that must be considered is load balancing issue that serves to distribute data traffic among multiple resources in order to maximize the efficiency and reliability of network resources. Load balancing is established based on the local information of the network in the conventional network. Hence, it is not very precise. However, SDN controllers have a global view of the network and can produce more optimized load balances. Although load balancing mechanisms are important in the SDN, to the best of our knowledge, there exists no precise and systematic review or survey on investigating these issues. Hence, this paper reviews the load balancing mechanisms which have been used in the SDN systematically based on two categories, deterministic and non-deterministic. Also, this paper represents benefits and some weakness regarded of the selected load balancing algorithms and investigates the metrics of their algorithms. In addition, the important challenges of these algorithms have been reviewed, so better load balancing techniques can be applied by the researchers in the future.
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paper_title: The Controller Placement Problem in Software Defined Networking: A Survey

paper_content:

Recently, a variety of solutions have been proposed to tackle the controller placement problem in SDN. The objectives include minimizing the latency between controllers and their associated switches, enhancing reliability and resilience of the network, and minimizing deployment cost and energy consumption. In this article, we first survey the state-of-the-art solutions and draw a taxonomy based on their objectives, and then propose a new approach to minimize the packet propagation latency between controllers and switches. In order to encourage future research, we also identify the ongoing research challenges and open issues relevant to this problem.
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Title: Advances in Software-Defined Technologies for Underwater Acoustic Sensor Networks: A Survey

Section 1: Introduction
Description 1: Provide an overview of the motivation, significance, and the main contributions of the survey in the context of underwater acoustic sensor networks (UASNs) and Software-Defined Networking (SDN).

Section 2: Preliminaries and Background
Description 2: Present fundamental concepts and previous studies related to Underwater Acoustic Sensor Networks (UASNs) and Software-Defined Networks (SDN).

Section 3: Progress on Software-Defined Underwater Acoustic Sensor Networks
Description 3: Detail the developments and innovations in Software-Defined Radio (SDR), Cognitive Radio (CR), and SDN as applied to UASNs.

Section 4: Current Issues and Potential Research Areas for SDN-Based UASNs
Description 4: Discuss the inherent challenges, existing issues, and opportunities for future research in the integration of SDN with UASNs.

Section 5: Conclusion
Description 5: Summarize the findings of the survey, highlighting the benefits of SDN for UASNs and the primary areas requiring further development.