Current Trends in Wireless Mesh Sensor Networks: A Review of Competing Approaches
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paper_title: Wireless mesh networks: a survey

paper_content:

Wireless mesh networks (WMNs) consist of mesh routers and mesh clients, where mesh routers have minimal mobility and form the backbone of WMNs. They provide network access for both mesh and conventional clients. The integration of WMNs with other networks such as the Internet, cellular, IEEE 802.11, IEEE 802.15, IEEE 802.16, sensor networks, etc., can be accomplished through the gateway and bridging functions in the mesh routers. Mesh clients can be either stationary or mobile, and can form a client mesh network among themselves and with mesh routers. WMNs are anticipated to resolve the limitations and to significantly improve the performance of ad hoc networks, wireless local area networks (WLANs), wireless personal area networks (WPANs), and wireless metropolitan area networks (WMANs). They are undergoing rapid progress and inspiring numerous deployments. WMNs will deliver wireless services for a large variety of applications in personal, local, campus, and metropolitan areas. Despite recent advances in wireless mesh networking, many research challenges remain in all protocol layers. This paper presents a detailed study on recent advances and open research issues in WMNs. System architectures and applications of WMNs are described, followed by discussing the critical factors influencing protocol design. Theoretical network capacity and the state-of-the-art protocols for WMNs are explored with an objective to point out a number of open research issues. Finally, testbeds, industrial practice, and current standard activities related to WMNs are highlighted.
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paper_title: Performance analysis of IEEE 802.15.4 non-beacon mode with the unslotted CSMA/CA

paper_content:

We provide a simple mathematical model of IEEE 802.15.4 unslotted CSMA/CA by busy cycle of M/G/l queueing system to obtain several performance measures. Our performance measures can be used for determining the optimal number of devices while supporting the required QoS constraints on the average packet delay and the packet loss probability, and also for calculating battery lifetime.
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paper_title: Low - rate wireless personal area networks

paper_content:

A buoyant body is carried by one or more stationary shafts that extend obliquely and freely, from securement adjacent to an end or ends thereof, in a body of water whose surface level varies with time. Each shaft extends through at least that depth portion of such body of water which comprehends the variations in surface level, and is interconnected with the buoyant body by means encircling the shaft for movement longitudinally therealong. Means are provided for converting into rotational energy the longitudinal travel of the buoyant body along the shaft as such buoyant body rises and falls with variations in water level.
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paper_title: A comprehensive simulation study of slotted CSMA/CA for IEEE 802.15.4 wireless sensor networks

paper_content:

In this paper, we analyze the performance limits of the slotted CSMA/CA mechanism of IEEE 802.15.4 in the beacon-enabled mode for broadcast transmissions in WSNs. The motivation for evaluating the beacon-enabled mode is due to its flexibility for WSN applications as compared to the non-beacon enabled mode. Our analysis is based on an accurate simulation model of the slotted CSMA/CA mechanism on top of a realistic physical layer, with respect to the IEEE 802.15.4 standard specification. The performance of the slotted CSMA/CA is evaluated and analyzed for different network settings to understand the impact of the protocol attributes (superframe order, beacon order and backoff exponent) on the network performance, namely in terms of throughput (S), average delay (D) and probability of success (Ps). We introduce the concept of utility (U) as a combination of two or more metrics, to determine the best offered load range for an optimal behavior of the network. We show that the optimal network performance using slotted CSMA/CA occurs in the range of 35% to 60% with respect to an utility function proportional to the network throughput (S) divided by the average delay (D).
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paper_title: IPv6 in Low-Power Wireless Networks

paper_content:

With deeply embedded wireless sensors, a new tier of the Internet is emerging that will extend into the physical world. These wireless sensor nodes are expected to vastly outnumber conventional computer hosts as we see them today, but their strict resource constraints are unlike other technologies already common to the Internet. As wireless sensor network research took off, many in the field eschewed the use of IP as inadequate and in contradiction to the needs of wireless sensor networking. Since then, the field has matured and IP has evolved. In this paper, we show that the convergence of Internet Protocol Version 6 (IPv6) and low-power multihop wireless networking is possible, pragmatic, and efficient-especially in regard to the metrics that matter most for embedded applications, low memory footprint, high reliability, and low energy usage. Using real commercial deployments, we show that it is possible to simultaneously achieve an average duty cycle of 99.9%, and average per-hop latency of <; 125 ms over 12 months in different environments.
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paper_title: Reliability and Energy-Efficiency in IEEE 802.15.4/ZigBee Sensor Networks: An Adaptive and Cross-Layer Approach

paper_content:

A major concern in wireless sensor networks (WSNs) is energy conservation, since battery-powered sensor nodes are expected to operate autonomously for a long time, e.g., for months or even years. Another critical aspect of WSNs is reliability, which is highly application-dependent. In most cases it is possible to trade-off energy consumption and reliability in order to prolong the network lifetime, while satisfying the application requirements. In this paper we propose an adaptive and cross-layer framework for reliable and energy-efficient data collection in WSNs based on the IEEE 802.15.4/ZigBee standards. The framework involves an energy-aware adaptation module that captures the application's reliability requirements, and autonomously configures the MAC layer based on the network topology and the traffic conditions in order to minimize the power consumption. Specifically, we propose a low-complexity distributed algorithm, called ADaptive Access Parameters Tuning (ADAPT), that can effectively meet the application-specific reliability under a wide range of operating conditions, for both single-hop and multi-hop networking scenarios. Our solution can be integrated into WSNs based on IEEE 802.15.4/ZigBee without requiring any modification to the standards. Simulation results show that ADAPT is very energy-efficient, with near-optimal performance.
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paper_title: A Non-beaconing ZigBee Network Implementation and Performance Study

paper_content:

In this paper we present our implementation of a layered ZigBee network and the performance test results using non-beaconing networks. Adding the implemented network layer to an existing IEEE 802.15.4 stack did not affect the throughput in the network. It is also concluded that with knowledge of the network structure an extra added delay between sending packets can reduce the number of packets lost due to channel access failure without decrease in throughput.
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paper_title: Performance evaluation of priority CSMA-CA mechanism on ISA100.11a wireless network

paper_content:

The International Society of Automation recently released ISA100.11a as an open standard for reliable wireless networks for industrial automation. ISA100.11a uses the TDMA scheme in the medium access layer to provide deterministic services. However, ISA100.11a adopts the CSMA-CA mechanism with priorities for retransmission from failure on dedicated links, sporadic data, and network configuration.This paper evaluates ISA100.11a CSMA-CA by simulation, considering the effects of backoff procedures and priority settings to probability of collision and successful use of slots. It's demonstrated that a high number of priority classes enable better network utilization resulting in less number of packets exceeding their lifetime. Research highlights Performance of CSMA-CA at ISA100.11a is evaluated with OPNET. ISA100.11a CSMA is for retransmission, sporadic data, and network configuration. Without priority setting, ISA100.11a CSMA uses bandwidth up to 35% as slotted ALOHA. Priority setting leads to higher bandwidth using, lower average end-to-end delay.
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paper_title: Performance comparison of wireless sensor network standard protocols in an aerospace environment: ISA100.11a and ZigBee Pro

paper_content:

Standards-based wireless sensor network (WSN) protocols are promising candidates for spacecraft avionic systems, offering unprecedented instrumentation flexibility and expandability. However, when migrating from wired to wireless data gathering systems, ensuring reliable data transport is a key consideration. In this paper, we conduct a rigorous laboratory analysis of the relative performance of the ZigBee Pro and ISA100.11a protocols in a representative crewed aerospace environment. Since both operate in the 2.4 GHz radio frequency (RF) band shared by systems such as Wi-Fi, they are subject at times to potentially debilitating RF interference. We compare message delivery rates achievable by both under varying levels of 802.11g Wi-Fi traffic. We conclude that while the simpler, more inexpensive ZigBee Pro protocol performs well under moderate levels of interference, the more complex and costly ISA100.11a protocol is needed to ensure reliable data delivery under heavier interference. This paper represents the first published, rigorous analysis of WSN protocols in an aerospace analog environment of which we are aware and the first published head-to-head comparison of ZigBee Pro and ISA100.11a.
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paper_title: Performance analysis of IEEE 802.15.4 and ZigBee for large-scale wireless sensor network applications

paper_content:

This paper analyses the performance of IEEE 802.15.4 Low-Rate Wireless Personal Area Network (LR-WPAN) in a large-scale Wireless Sensor Network (WSN) application. To minimize the energy consumption of the entire network and to allow adequate network coverage, IEEE 802.15.4 peer-to-peer topology is selected, and configured to a beacon-enabled cluster-tree structure. The analysis consists of models for CSMA-CA mechanism and MAC operations specified by IEEE 802.15.4. Network layer operations in a cluster-tree network specified by ZigBee are included in the analysis. For realistic results, power consumption measurements on an IEEE 802.15.4 evaluation board are also included. The performances of a device and a coordinator are analyzed in terms of power consumption and goodput. The results are verified with simulations using WIreless SEnsor NEtwork Simulator (WISENES). The results depict that the minimum device power consumption is as low as 73 μW, when beacon interval is 3.93 s, and data are transmitted at 4 min intervals. Coordinator power consumption and goodput with 15.36 ms CAP duration and 3.93 s beacon interval are around 370 μW and 34 bits/s
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paper_title: TSMP: Time Synchronized Mesh Protocol

paper_content:

The Time Synchronized Mesh Protocol (TSMP) enables reliable, low power, secure communication in a managed wireless mesh network. TSMP is a medium access and networking protocol designed for the recently ratified Wireless HART standard in industrial automation. TSMP benefits from synchronization of nodes in a multi-hop network to within a few hundred microseconds, allowing scheduling of collision-free pair-wise and broadcast communication to meet the traffic needs of all nodes while cycling through all available channels. Latency and reliability guarantees can be traded off for energy use, though our focus has been on providing high reliability (>99.9%) networks at the lowest power possible. TSMP has been demonstrated in multi-hop networks exceeding 250 nodes per access point, thousands of nodes with multiple access points, radio duty cycles of 0.01%, and with devices at radically different temperatures and traffic levels. With the 802.15.4 physical layer and 10 ms time slots, TSMP can theoretically achieve a secure payload throughput of 76 kbps at a single egress point.
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paper_title: Performance evaluation of WirelessHART for factory automation

paper_content:

The WirelessHART specification has given the industry access to their first open standard specifically aimed at wireless instrumentation for factory automation. For WirelessHART to be a viable solution for the process and automation industry, it has to provide a robust and reliable alternative to today's wired networks.
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paper_title: IP is dead, long live IP for wireless sensor networks

paper_content:

A decade ago as wireless sensor network research took off many researchers in the field denounced the use of IP as inadequate and in contradiction to the needs of wireless sensor networking. Since then the field has matured, standard links have emerged, and IP has evolved. In this paper, we present the design of a complete IPv6-based network architecture for wireless sensor networks. We validate the architecture with a production-quality implementation that incorporates many techniques pioneered in the sensor network community, including duty-cycled link protocols, header compression, hop-by-hop forwarding, and efficient routing with effective link estimation. In addition to providing interoperability with existing IP devices, this implementation was able to achieve an average duty-cycle of 0.65%, average per-hop latency of 62ms, and a data reception rate of 99.98% over a period of 4 weeks in a real-world home-monitoring application where each node generates one application packet per minute. Our results outperform existing systems that do not adhere to any particular standard or architecture. In light of this demonstration of full IPv6 capability, we review the central arguments that led the field away from IP. We believe that the presence of an architecture, specifically an IPv6-based one, provides a strong foundation for wireless sensor networks going forward.
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paper_title: Performance evaluation of the 6LoWPAN protocol on MICAz and TelosB motes

paper_content:

For wireless sensor networks to reach their full potential they need to be able to interoperate with external IPv6 based networks. This can be achieved using the light-weight 6LoWPAN (IPv6 over Low power Wireless Personal Area Networks) communications protocol that has been designed to operate within the limited processing, memory and energy power constraints associated with Wireless Sensor Networks. In this paper the TinyOS Berkeley 6LoWPAN implementation is configured, deployed and tested on both the MICAz and the TelosB sensor architectures. A performance evaluation of point-to-point communications from a computer to a sensor mote is then carried out over an IPv6/6LoWPAN network.
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paper_title: IPv6 in Low-Power Wireless Networks

paper_content:

With deeply embedded wireless sensors, a new tier of the Internet is emerging that will extend into the physical world. These wireless sensor nodes are expected to vastly outnumber conventional computer hosts as we see them today, but their strict resource constraints are unlike other technologies already common to the Internet. As wireless sensor network research took off, many in the field eschewed the use of IP as inadequate and in contradiction to the needs of wireless sensor networking. Since then, the field has matured and IP has evolved. In this paper, we show that the convergence of Internet Protocol Version 6 (IPv6) and low-power multihop wireless networking is possible, pragmatic, and efficient-especially in regard to the metrics that matter most for embedded applications, low memory footprint, high reliability, and low energy usage. Using real commercial deployments, we show that it is possible to simultaneously achieve an average duty cycle of 99.9%, and average per-hop latency of <; 125 ms over 12 months in different environments.
---
paper_title: Low - rate wireless personal area networks

paper_content:

A buoyant body is carried by one or more stationary shafts that extend obliquely and freely, from securement adjacent to an end or ends thereof, in a body of water whose surface level varies with time. Each shaft extends through at least that depth portion of such body of water which comprehends the variations in surface level, and is interconnected with the buoyant body by means encircling the shaft for movement longitudinally therealong. Means are provided for converting into rotational energy the longitudinal travel of the buoyant body along the shaft as such buoyant body rises and falls with variations in water level.
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paper_title: Traffic Aware Scheduling Algorithm for reliable low-power multi-hop IEEE 802.15.4e networks

paper_content:

The Time Synchronized Channel Hopping (TSCH) protocol is part of the newly defined IEEE 802.15.4e standard and represents the latest generation of highly reliable low-power MAC protocols. With implementation details left open, we conceive here a novel Traffic Aware Scheduling Algorithm (TASA) by extending the theoretically well-established graph theory methods of matching and coloring by means of an innovative approach based on network topology and traffic load. TASA is able to support emerging industrial applications requiring low latency at low duty cycle and power consumption. Preliminary simulation results have also been reported to highlight the effectiveness of the proposed algorithm.
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paper_title: Adaptive Synchronization in IEEE802.15.4e Networks

paper_content:

Industrial low-power wireless mesh networks are shifting towards time-synchronized medium access control (MAC) protocols which are able to yield over 99.9% end-to-end reliability and radio duty cycles well below 1%. In these networks, motes use time slots to communicate, and neighbor motes maintain their clocks' alignment, typically within 1 ms. Temperature, supply voltage, and fabrication differences cause the motes' clocks to drift with respect to one another. Neighbor motes need to re-synchronize periodically through pairwise communication. This period is typically determined a priori, based on the worst case drift. In this paper, we propose a novel technique which measures and models the relative clock drift between neighbor motes, thereby reducing the effective drift rate. Instead of resynchronizing at a preset rate, neighbor motes resynchronize only when needed. This reduces the minimum achievable duty cycle of an idle network by a factor of 10, which in turn lowers the mote power consumption and extends the network lifetime. This Adaptive Synchronization is implemented as part of IEEE802.15.4e in the OpenWSN protocol stack and is validated through extensive experimentation.
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paper_title: Realistic and Efficient Multi-Channel Communications in Wireless Sensor Networks

paper_content:

This paper demonstrates how to use multiple channels to improve communication performance in Wireless Sensor Networks (WSNs). We first investigate multi-channel realities in WSNs through intensive empirical experiments with Micaz motes. Our study shows that current multi-channel protocols are not suitable for WSNs, because of the small number of available channels and unavoidable time errors found in real networks. With these observations, we propose a novel tree-based multichannel scheme for data collection applications, which allocates channels to disjoint trees and exploits parallel transmissions among trees. In order to minimize interference within trees, we define a new channel assignment problem which is proven NP- complete. Then we propose a greedy channel allocation algorithm which outperforms other schemes in dense networks with a small number of channels.We implement our protocol, called TMCP, in a real testbed. Through both simulation and real experiments, we show that TMCP can significantly improve network throughput and reduce packet losses. More importantly, evaluation results show that TMCP better accommodates multi-channel realities found in WSNs than other multi-channel protocols.
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paper_title: Towards IEEE 802.15.4e: A study of performance aspects

paper_content:

We discuss the applicability of IEEE 802.15.4 for application in industrial automation. Based on the specific requirements in this field, especially w.r.t. real-time operation, we analyzed the weaknesses of the standard protocol and proposed a novel MAC protocol that keeps the original PHY definition in order to work using available IEEE 802.15.4 chipsets. In earlier work, we analytically derived the worst case latency for using the improved protocol version in typical industrial setups. We now also implemented this protocol version in a simulation environment in order to show the typical behavior in the network taking into account typical channel conditions. We performed extensive simulation experiments that show the limitations of the standard protocol and that demonstrate the capabilities of the new protocol in a selected automation scenario. Our protocol variant is going to become the forthcoming IEEE 802.15.4e standard.
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paper_title: Low - rate wireless personal area networks

paper_content:

A buoyant body is carried by one or more stationary shafts that extend obliquely and freely, from securement adjacent to an end or ends thereof, in a body of water whose surface level varies with time. Each shaft extends through at least that depth portion of such body of water which comprehends the variations in surface level, and is interconnected with the buoyant body by means encircling the shaft for movement longitudinally therealong. Means are provided for converting into rotational energy the longitudinal travel of the buoyant body along the shaft as such buoyant body rises and falls with variations in water level.
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paper_title: Performance evaluation of IEEE 802.15.4e DSME MAC protocol for wireless sensor networks

paper_content:

In this paper, we evaluate performance of time synchronized multi-channel MAC protocol called DSME for wireless sensor networks. DSME MAC enhances IEEE 802.15.4 MAC specification, which provides backward compatibility and adds new features such as multichannel extension to the current single channel based superframe structure; enhancing peer-to-peer communications. Our numerical results show that throughput of DSME MAC protocol is 12 times higher against IEEE802.15.4-2006 slotted CSMA/CA in a multi-hop network with a 5×5 square grid device deployment. Energy consumption of DSME MAC protocol remains constant as the number of endpoint devices increases, while that of slotted CSMA/CA increases exponentially in star device deployment, thus, life span of a device can be increased substantially by employing DSME MAC protocol for the applications with large number of endpoint devices such as smart metering and infrastructure monitoring.
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paper_title: Experimental Evaluation of Beacon Scheduling Mechanisms for Multihop IEEE 802.15.4 Wireless Sensor Networks

paper_content:

Recently, several scheduling techniques to enable multihop communications in the beacon enabled mode of the IEEE 802.15.4 standard have been proposed. Using the beacon enabled mode allows node synchronization and hence energy savings which is an important concern in wireless sensor networks (WSNs). However, and to the best of our knowledge, current available scheduling techniques have not been formally compared. This makes it difficult to decide which technique gives a better performance with regard to different WSN scenarios or applications. In this paper, we compare the two most popular methods for beacon enabled multihop IEEE 802.15.4 WSNs for different scenarios and performance parameters. Based on our findings, we propose recommendations for the use of each scheduling technique.
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paper_title: Performance analysis of IEEE 802.15.4e DSME MAC protocol under WLAN interference

paper_content:

In this paper, we analyze the performance of IEEE 802.15.4e DSME-enabled wireless sensor network (WSN) and IEEE 802.15.4 beacon-enabled WSN employing slotted CSMA/CA in terms of frame error rate and aggregate throughput under the influence of IEEE 802.11b wireless LAN (WLAN) interference. The main purpose of this paper is to provide helpful information in the design of DSME-enabled WSNs in the presence of WLAN interference. Our numerical results show that DSME MAC protocol is resilient to large variance of traffic load conditions (Λ wlan ) and interference power level of WLAN. It is observed that the dominant interference source is homogeneous WSN devices in IEEE 802.15.4 WSN employing slotted CSMA/CA for small value of Λ wlan , while WLAN devices are always the dominant interference sources in DSME-enabled WSNs regardless of Λ wlan . Meanwhile, it is observed that DSME-enabled WSN retains high aggregate throughput value for large range of interference power level, while the aggregate throughput of IEEE 802.15.4 WSN employing slotted CSMA/CA degrades severely as the WLAN device approaches to WSN devices.
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paper_title: BOP (Beacon-Only Period) and Beacon Scheduling for MEU (Mesh-Enabled USN) Devices

paper_content:

In this paper, we proposed a new concept of BOP (beacon-only period) and relevant beacon scheduling mechanism that will avoid beacon conflicts between MEU (mesh-enabled USN) devices all of whom are transmitting their beacons. The beacon scheduling for the MEU devices makes all the devices of the overall network completely synchronized and operate in a stable manner. Moreover, the synchronization of the MEU devices of the network based on the beacon scheduling allows the network to save power consumptions drastically.
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paper_title: IEEE 802.15.5 WPAN mesh standard-low rate part: Meshing the wireless sensor networks

paper_content:

This paper introduces a new IEEE standard, IEEE 802.15.5,which provides mesh capability for wireless personal area network (WPAN) devices. The standard provides an architectural framework enabling WPAN devices to promote interoperable, stable, and scalable wireless mesh topologies. It is composed of two parts: low-rate WPAN mesh and high-rate WPAN mesh. In this paper, we present only low-rate WPAN mesh because it is designed to support wireless sensor networks. IEEE 802.15.5 low-rate part is a light-weight scalable mesh routing protocol that caters well to the requirements of resource-constrained wireless sensor networks. By binding logical addresses to the network topology, IEEE 802.15.5 obviates the need for route discovery. This eliminates the initial route discovery latency, saves storage space and reduces the communication overhead and energy consumption. A distributed link state scheme is further built atop the block addressing scheme to improve the quality of routes, robustness, and load balancing. The routing scheme scales well with regard to various performance metrics. The standard also provides enhanced functions such as multicast, reliable broadcast, power saving, time synchronization, route tracing and portability. We also present the performance evaluation of major functions performed with a 50-nodes tested deployed over a whole floor (100 × 140 ft2) at CUNY Engineering building. The results testify that the IEEE 802.15.5 will serve well for wireless personal area networks and wireless sensor networks.
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paper_title: On the synchronization of IEEE 802.15.5 wireless mesh sensor networks: Shortcomings and improvements

paper_content:

As part of the recent IEEE 802.15.5 wireless mesh sensor networks (WMSN) standard, Synchronous Energy Saving (SES) is planned to provide energy savings to scheduled communications with strict temporal requirements that, a priori, facilitate the development of delay-sensitive applications. It is accomplished by means of different mechanisms, among which we highlight a straightforward synchronization process. However, the SES synchronization scheme introduces variable delays in the dissemination of information and reduces the lifetime of the nodes and the entire network significantly, thus limiting the full exploitation of SES. This article presents a new synchronization approach, that we call Hi gh- Pe rformance Syn chronization Algorithm for wireless mesh sensor networks (HIPESYN), which is adapted to the IEEE 802.15.5 standard for synchronous communications. HIPESYN supports intensive bandwidth applications in a much better way than with the original design. The proposed algorithm is also thoroughly evaluated and its results carefully discussed.
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paper_title: Sensing the world: Challenges on WSNs

paper_content:

Wireless sensor network (WSNs) is a demanding multidisciplinary field that has been target of research in the last decade. The increasing demand for security and automated monitoring of things and places makes WSNs a promising technology although there are still many open research contributions needed to make this the standard of environmental sensing. The goal of this article is to identify the research challenges on WSNs by dividing them into functional groups, building on previous work. We followed a structured approach based on a simplified yet complete vision of a design space for WSNs. Moreover, this work aims to identify research gaps and investigation fields yet unexplored or hardly explored by researchers in order to plot paths for future research. Several challenges and research areas were identified, like Models for Sensor Networks, Benchmarking Methodologies, Distributed Processing, Interface WSNs and Network Reprogramming. Some of these challenges will become even clearer as increasingly WSNs become Wireless Sensor and Actuator Networks (WSANs).
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paper_title: Improved mesh WSN support for a realistic mobility model

paper_content:

This paper considers a realistic mobility model for a military application scenario using a wireless mesh sensor network. Within this model, the sink moves at the network boundary joining and leaving the network for different periods of time. Although the IEEE 802.15.5 standard has portability support for peripheral nodes (leaf devices) and is officially recommended for use in wireless mesh sensor networks, it is shown here that it can't support the new mobility model proposed in this paper. Two solutions are suggested and discussed, the waiting for the destination and following the destination concepts.
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paper_title: Testbed Experimentation of a Meshed Tree Routing with Local Link State for Wireless PAN Mesh

paper_content:

This paper focus on the testbed experimentation of a meshed tree routing algorithm with local link state for wireless personal area networks (WPANs) based on current IEEE 802.15.4 MAC and PHY. The meshed tree uses a block addressing scheme based on tree structure and local link state information for mesh routing. Our approach exploits the information from the global tree structure for the direction of packet forwarding and local link state for choosing the next hop toward the destination. It has two prominent features: scalability and fault tolerance. Each node maintains a local link state of k-hop(usually 2-hop) information regardless of network size, which makes the approach scalable. Being a mesh, our approach shows good fault tolerance and load balancing. Testbed experiments show that the meshed tree displays superior performance when compared with AODV and a tree based algorithm. Comparisons were made with respect to packet deliver ratio, energy consumption and memory usage. The proposed algorithm is being considered as the routing algorithm for IEEE 802.15.5 WPANMesh standard.
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paper_title: IPv6 in Low-Power Wireless Networks

paper_content:

With deeply embedded wireless sensors, a new tier of the Internet is emerging that will extend into the physical world. These wireless sensor nodes are expected to vastly outnumber conventional computer hosts as we see them today, but their strict resource constraints are unlike other technologies already common to the Internet. As wireless sensor network research took off, many in the field eschewed the use of IP as inadequate and in contradiction to the needs of wireless sensor networking. Since then, the field has matured and IP has evolved. In this paper, we show that the convergence of Internet Protocol Version 6 (IPv6) and low-power multihop wireless networking is possible, pragmatic, and efficient-especially in regard to the metrics that matter most for embedded applications, low memory footprint, high reliability, and low energy usage. Using real commercial deployments, we show that it is possible to simultaneously achieve an average duty cycle of 99.9%, and average per-hop latency of <; 125 ms over 12 months in different environments.
---
paper_title: Performance analysis of IEEE 802.15.4 non-beacon mode with the unslotted CSMA/CA

paper_content:

We provide a simple mathematical model of IEEE 802.15.4 unslotted CSMA/CA by busy cycle of M/G/l queueing system to obtain several performance measures. Our performance measures can be used for determining the optimal number of devices while supporting the required QoS constraints on the average packet delay and the packet loss probability, and also for calculating battery lifetime.
---
paper_title: On the synchronization of IEEE 802.15.5 wireless mesh sensor networks: Shortcomings and improvements

paper_content:

As part of the recent IEEE 802.15.5 wireless mesh sensor networks (WMSN) standard, Synchronous Energy Saving (SES) is planned to provide energy savings to scheduled communications with strict temporal requirements that, a priori, facilitate the development of delay-sensitive applications. It is accomplished by means of different mechanisms, among which we highlight a straightforward synchronization process. However, the SES synchronization scheme introduces variable delays in the dissemination of information and reduces the lifetime of the nodes and the entire network significantly, thus limiting the full exploitation of SES. This article presents a new synchronization approach, that we call Hi gh- Pe rformance Syn chronization Algorithm for wireless mesh sensor networks (HIPESYN), which is adapted to the IEEE 802.15.5 standard for synchronous communications. HIPESYN supports intensive bandwidth applications in a much better way than with the original design. The proposed algorithm is also thoroughly evaluated and its results carefully discussed.
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paper_title: W-MAC: Supporting Ultra Low Duty Cycle in Wireless Sensor Networks

paper_content:

The duty cycle of a wireless sensor node is a key factor that determines the life time of a wireless sensor network. In general, sensor medium access control protocols reduce the duty cycle to achieve longer lifetime. However, we found out that their performance improvements substantially decrease under extremely low duty cycles ( 0.1%). It is with estimation of the relative clock speed between the sender and the receiver, and uses it to minimize energy consumption. It saves energy significantly well compared to the existing schemes in an order of ten times, and the performance gap increases with lowering the duty cycle.
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paper_title: IEEE 802.15.5 WPAN mesh standard-low rate part: Meshing the wireless sensor networks

paper_content:

This paper introduces a new IEEE standard, IEEE 802.15.5,which provides mesh capability for wireless personal area network (WPAN) devices. The standard provides an architectural framework enabling WPAN devices to promote interoperable, stable, and scalable wireless mesh topologies. It is composed of two parts: low-rate WPAN mesh and high-rate WPAN mesh. In this paper, we present only low-rate WPAN mesh because it is designed to support wireless sensor networks. IEEE 802.15.5 low-rate part is a light-weight scalable mesh routing protocol that caters well to the requirements of resource-constrained wireless sensor networks. By binding logical addresses to the network topology, IEEE 802.15.5 obviates the need for route discovery. This eliminates the initial route discovery latency, saves storage space and reduces the communication overhead and energy consumption. A distributed link state scheme is further built atop the block addressing scheme to improve the quality of routes, robustness, and load balancing. The routing scheme scales well with regard to various performance metrics. The standard also provides enhanced functions such as multicast, reliable broadcast, power saving, time synchronization, route tracing and portability. We also present the performance evaluation of major functions performed with a 50-nodes tested deployed over a whole floor (100 × 140 ft2) at CUNY Engineering building. The results testify that the IEEE 802.15.5 will serve well for wireless personal area networks and wireless sensor networks.
---
paper_title: Low - rate wireless personal area networks

paper_content:

A buoyant body is carried by one or more stationary shafts that extend obliquely and freely, from securement adjacent to an end or ends thereof, in a body of water whose surface level varies with time. Each shaft extends through at least that depth portion of such body of water which comprehends the variations in surface level, and is interconnected with the buoyant body by means encircling the shaft for movement longitudinally therealong. Means are provided for converting into rotational energy the longitudinal travel of the buoyant body along the shaft as such buoyant body rises and falls with variations in water level.
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paper_title: Low-power wireless IPv6 routing with ContikiRPL

paper_content:

RPL is the IETF candidate standard for IPv6 routing in low-power wireless sensor networks. We present the first experimental results of RPL which we have obtained with our ContikiRPL implementation. Our results show that Tmote Sky motes running IPv6 with RPL routing have a battery lifetime of years, while delivering 0.6 packets per second to a sink node.
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paper_title: On the synchronization of IEEE 802.15.5 wireless mesh sensor networks: Shortcomings and improvements

paper_content:

As part of the recent IEEE 802.15.5 wireless mesh sensor networks (WMSN) standard, Synchronous Energy Saving (SES) is planned to provide energy savings to scheduled communications with strict temporal requirements that, a priori, facilitate the development of delay-sensitive applications. It is accomplished by means of different mechanisms, among which we highlight a straightforward synchronization process. However, the SES synchronization scheme introduces variable delays in the dissemination of information and reduces the lifetime of the nodes and the entire network significantly, thus limiting the full exploitation of SES. This article presents a new synchronization approach, that we call Hi gh- Pe rformance Syn chronization Algorithm for wireless mesh sensor networks (HIPESYN), which is adapted to the IEEE 802.15.5 standard for synchronous communications. HIPESYN supports intensive bandwidth applications in a much better way than with the original design. The proposed algorithm is also thoroughly evaluated and its results carefully discussed.
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paper_title: Low-Rate WPAN Mesh Network - An Enabling Technology for Ubiquitous Networks

paper_content:

This article presents an in-depth introduction and analysis of the low-data-rate portion of the IEEE standard 802.15.5 that targets on providing mesh capabilities to low-rate Wireless Personal Area Networks. As major contributors of this standard, we seek to share our insights and motivations of the approaches adopted in the major components of the standard instead of presenting a la carte items drawn in the specification. We wish this article helps readers of the 802.15.5 standard to better understand the rationale and intent of the protocol design. This article also compares 802.15.5 to ZigBee™ and 6LoWPAN, for users to select the best mesh network technology for their applications.
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paper_title: Versatile low power media access for wireless sensor networks

paper_content:

We propose B-MAC, a carrier sense media access protocol for wireless sensor networks that provides a flexible interface to obtain ultra low power operation, effective collision avoidance, and high channel utilization. To achieve low power operation, B-MAC employs an adaptive preamble sampling scheme to reduce duty cycle and minimize idle listening. B-MAC supports on-the-fly reconfiguration and provides bidirectional interfaces for system services to optimize performance, whether it be for throughput, latency, or power conservation. We build an analytical model of a class of sensor network applications. We use the model to show the effect of changing B-MAC's parameters and predict the behavior of sensor network applications. By comparing B-MAC to conventional 802.11-inspired protocols, specifically SMAC, we develop an experimental characterization of B-MAC over a wide range of network conditions. We show that B-MAC's flexibility results in better packet delivery rates, throughput, latency, and energy consumption than S-MAC. By deploying a real world monitoring application with multihop networking, we validate our protocol design and model. Our results illustrate the need for flexible protocols to effectively realize energy efficient sensor network applications.
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paper_title: X-MAC: a short preamble MAC protocol for duty-cycled wireless sensor networks

paper_content:

In this paper we present X-MAC, a low power MAC protocol for wireless sensor networks (WSNs). Standard MAC protocols developed for duty-cycled WSNs such as BMAC, which is the default MAC protocol for TinyOS, employ an extended preamble and preamble sampling. While this “low power listening” approach is simple, asynchronous, and energy-efficient, the long preamble introduces excess latency at each hop, is suboptimal in terms of energy consumption, and suffers from excess energy consumption at nontarget receivers. X-MAC proposes solutions to each of these problems by employing a shortened preamble approach that retains the advantages of low power listening, namely low power communication, simplicity and a decoupling of transmitter and receiver sleep schedules. We demonstrate through implementation and evaluation in a wireless sensor testbed that X-MAC’s shortened preamble approach significantly reduces energy usage at both the transmitter and receiver, reduces per-hop latency, and offers additional advantages such as flexible adaptation to both bursty and periodic sensor data sources.
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paper_title: IEEE 802.15.5 WPAN mesh standard-low rate part: Meshing the wireless sensor networks

paper_content:

This paper introduces a new IEEE standard, IEEE 802.15.5,which provides mesh capability for wireless personal area network (WPAN) devices. The standard provides an architectural framework enabling WPAN devices to promote interoperable, stable, and scalable wireless mesh topologies. It is composed of two parts: low-rate WPAN mesh and high-rate WPAN mesh. In this paper, we present only low-rate WPAN mesh because it is designed to support wireless sensor networks. IEEE 802.15.5 low-rate part is a light-weight scalable mesh routing protocol that caters well to the requirements of resource-constrained wireless sensor networks. By binding logical addresses to the network topology, IEEE 802.15.5 obviates the need for route discovery. This eliminates the initial route discovery latency, saves storage space and reduces the communication overhead and energy consumption. A distributed link state scheme is further built atop the block addressing scheme to improve the quality of routes, robustness, and load balancing. The routing scheme scales well with regard to various performance metrics. The standard also provides enhanced functions such as multicast, reliable broadcast, power saving, time synchronization, route tracing and portability. We also present the performance evaluation of major functions performed with a 50-nodes tested deployed over a whole floor (100 × 140 ft2) at CUNY Engineering building. The results testify that the IEEE 802.15.5 will serve well for wireless personal area networks and wireless sensor networks.
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paper_title: An efficient multicast routing in IEEE 802.15.5 networks

paper_content:

The IEEE 802.15.5 standard for WPAN mesh adds mesh links to a tree structure for efficient communications for unicast routing. However, for multicasting, the basic tree routing scheme which does not exploit mesh links is adopted, which leads to inefficient multicasting. In this paper, we propose ‘MTM (Multicast Tree with Mesh)’ routing scheme which leverages mesh links for multicast routing. The proposed scheme shows better performance than the basic tree routing of IEEE 802.15.5 standard in terms of the number of participating nodes in multicast trees, control message overhead, and the number of data transmissions.
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paper_title: On the synchronization of IEEE 802.15.5 wireless mesh sensor networks: Shortcomings and improvements

paper_content:

As part of the recent IEEE 802.15.5 wireless mesh sensor networks (WMSN) standard, Synchronous Energy Saving (SES) is planned to provide energy savings to scheduled communications with strict temporal requirements that, a priori, facilitate the development of delay-sensitive applications. It is accomplished by means of different mechanisms, among which we highlight a straightforward synchronization process. However, the SES synchronization scheme introduces variable delays in the dissemination of information and reduces the lifetime of the nodes and the entire network significantly, thus limiting the full exploitation of SES. This article presents a new synchronization approach, that we call Hi gh- Pe rformance Syn chronization Algorithm for wireless mesh sensor networks (HIPESYN), which is adapted to the IEEE 802.15.5 standard for synchronous communications. HIPESYN supports intensive bandwidth applications in a much better way than with the original design. The proposed algorithm is also thoroughly evaluated and its results carefully discussed.
---
paper_title: Low-Rate WPAN Mesh Network - An Enabling Technology for Ubiquitous Networks

paper_content:

This article presents an in-depth introduction and analysis of the low-data-rate portion of the IEEE standard 802.15.5 that targets on providing mesh capabilities to low-rate Wireless Personal Area Networks. As major contributors of this standard, we seek to share our insights and motivations of the approaches adopted in the major components of the standard instead of presenting a la carte items drawn in the specification. We wish this article helps readers of the 802.15.5 standard to better understand the rationale and intent of the protocol design. This article also compares 802.15.5 to ZigBee™ and 6LoWPAN, for users to select the best mesh network technology for their applications.
---
paper_title: Improved mesh WSN support for a realistic mobility model

paper_content:

This paper considers a realistic mobility model for a military application scenario using a wireless mesh sensor network. Within this model, the sink moves at the network boundary joining and leaving the network for different periods of time. Although the IEEE 802.15.5 standard has portability support for peripheral nodes (leaf devices) and is officially recommended for use in wireless mesh sensor networks, it is shown here that it can't support the new mobility model proposed in this paper. Two solutions are suggested and discussed, the waiting for the destination and following the destination concepts.
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paper_title: Wireless Multimedia Sensor Networks: Current Trends and Future Directions

paper_content:

Wireless Multimedia Sensor Networks (WMSNs) have emerged and shifted the focus from the typical scalar wireless sensor networks to networks with multimedia devices that are capable to retrieve video, audio, images, as well as scalar sensor data. WMSNs are able to deliver multimedia content due to the availability of inexpensive CMOS cameras and microphones coupled with the significant progress in distributed signal processing and multimedia source coding techniques. In this paper, we outline the design challenges of WMSNs, give a comprehensive discussion of the proposed architectures, algorithms and protocols for the different layers of the communication protocol stack for WMSNs, and evaluate the existing WMSN hardware and testbeds. The paper will give the reader a clear view of the state of the art at all aspects of this research area, and shed the light on its main current challenges and future trends. We also hope it will foster discussions and new research ideas among its researchers.
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paper_title: Testbed Experimentation of a Meshed Tree Routing with Local Link State for Wireless PAN Mesh

paper_content:

This paper focus on the testbed experimentation of a meshed tree routing algorithm with local link state for wireless personal area networks (WPANs) based on current IEEE 802.15.4 MAC and PHY. The meshed tree uses a block addressing scheme based on tree structure and local link state information for mesh routing. Our approach exploits the information from the global tree structure for the direction of packet forwarding and local link state for choosing the next hop toward the destination. It has two prominent features: scalability and fault tolerance. Each node maintains a local link state of k-hop(usually 2-hop) information regardless of network size, which makes the approach scalable. Being a mesh, our approach shows good fault tolerance and load balancing. Testbed experiments show that the meshed tree displays superior performance when compared with AODV and a tree based algorithm. Comparisons were made with respect to packet deliver ratio, energy consumption and memory usage. The proposed algorithm is being considered as the routing algorithm for IEEE 802.15.5 WPANMesh standard.
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Title: Current Trends in Wireless Mesh Sensor Networks: A Review of Competing Approaches

Section 1: Introduction
Description 1: Introduce the basic concept of Wireless Mesh Sensor Networks (WMSNs) and their foundational aspects.

Section 2: Recent Advances on IEEE 802.15.4-Based WMSN Approaches
Description 2: Summarize the current state of the art focusing on the most relevant approaches providing conventional LR-WPAN with mesh capability.

Section 3: WMSN Solutions Developed on SP100.11a
Description 3: Discuss the WMSN standards WirelessHART and ISA SP100.11a, focusing on their implementation and use in the industrial sector.

Section 4: IETF: 6LoWPAN and ROLL
Description 4: Explain the contributions of the Internet Engineering Task Force (IETF) in adapting the IPv6 Internet protocol onto the IEEE 802.15.4 standard MAC and PHY layers.

Section 5: IP500 ® Alliance
Description 5: Detail the mesh solutions provided by the IP500 ® Alliance, emphasizing their objectives and implementations.

Section 6: IEEE 802.15.4e: The TSCH Protocol
Description 6: Describe the TSCH protocol included in the IEEE 802.15.4e specification, its advantages, and drawbacks.

Section 7: WMSN Solutions Developed on Top of the IEEE 802.15.4 PHY and MAC (Beacon Mode) Layers: IEEE 802.15.4e (DSME)
Description 7: Highlight the DSME mechanism from the IEEE 802.15.4e-2012 standard and its scheduling techniques to mitigate message collisions in mesh networks.

Section 8: Overview of Current WMSNs Approaches
Description 8: Provide an overall evaluation of the discussed WMSN proposals, their limitations, and potential solutions.

Section 9: The IEEE 802.15.5 WPAN Mesh Standard
Description 9: Focus on the IEEE 802.15.5 WPAN mesh standard, its benefits, functionalities, and comparison with other proposals.

Section 10: Synchronous Communications: SES
Description 10: Explain the Synchronous Energy Saving (SES) mechanism and its role in supporting delay-sensitive applications.

Section 11: Asynchronous Communications: ASES
Description 11: Describe the Asynchronous Energy Saving (ASES) mechanism for applications without strict time requirements.

Section 12: Comparative Analysis based on the Design Guidelines
Description 12: Provide a comparative analysis of different WMSN proposals based on various design guidelines and main requirements identified.

Section 13: IEEE 802.15.5 Discussion and Future Trends
Description 13: Discuss the current state, future challenges, and potential improvements for the IEEE 802.15.5 standard.

Section 14: Conclusions
Description 14: Summarize the findings of the review, highlighting key points, and suggesting directions for future research in WMSN technology.