Congestion Control Techniques in WSNs: A Review
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paper_title: A Light-Weight Opportunistic Forwarding Protocol with Optimized Preamble Length for Low-Duty-Cycle Wireless Sensor Networks

paper_content:

In wireless sensor networks, sensed information is expected to be reliably and timely delivered to a sink in an ad-hoc way. However, it is challenging to achieve this goal because of the highly dynamic topology induced from asynchronous duty cycles and temporally and spatially varying link quality among nodes. Currently some opportunistic forwarding protocols have been proposed to address the challenge. However, they involve complicated mechanisms to determine the best forwarder at each hop, which incurs heavy overheads for the resource-constrained nodes. In this paper, we propose a light-weight opportunistic forwarding (LWOF) scheme. Different from other recently proposed opportunistic forwarding schemes, LWOF employs neither historical network information nor a contention process to select a forwarder prior to data transmissions. It confines forwarding candidates to an optimized area, and takes advantage of the preamble in low-power-listening (LPL) MAC protocols and dual-channel communication to forward a packet to a unique downstream node towards the sink with a high probability, without making a forwarding decision prior to data transmission. Under LWOF, we optimize LPL MAC protocol to have a shortened preamble (LWMAC), based on a theoretical analysis on the relationship among preamble length, delivery probability at each hop, node density and sleep duration. Simulation results show that LWOF, along with LWMAC, can achieve relatively good performance in terms of delivery reliability and latency, as a receiver-based opportunistic forwarding protocol, while reducing energy consumption per packet by at least twice.
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paper_title: Secure Data Aggregation In Wireless Sensor Networks

paper_content:

Wireless sensor networks (WSNs) usually consists of a large number of sensors which have limited capability in terms of communication, computation and memory [1] (Akyildiz et al. IEEE Commun. Mag. 40 (8), 102–114, 2002), [2] (Yick et al. Comput. Networks, 52 (12), 2292–2330, 2008). These sensors are deployed in a remote and unsurveillant field and they autonomously form before they engage in a predefined sensing task. WSNs renders possible solutions to many problems in both civilian and military applications, including temperature monitoring, wildfire detection, animal tracking, and battlefield surveillance. Therefore, it is challenging to come up with efficient ways to collect desired data, given the sensors only have simple hardware and software resources. For instance, most of the sensors only have a short lifetime due to the non-rechargeable battery which is a bottleneck for designing WSNs protocols.
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paper_title: A Congestion-Aware Routing Algorithms Based on Traffic Priority in Wireless Sensor Networks

paper_content:

Wireless sensor network allow the network manager to measure the observed events in a short radio range and give them an appropriate response. In many applications of wireless sensor network, due to the high volume of traffic, probability of congestion and packet loss increases. Congestion in sensor networks has a direct effect on energy efficiency and quality of service applications. Congestion may cause a buffer overflow, longer queuing time and higher packet loss. Packet loss not only reduces the reliability and quality of service application but also wastes energy. In this paper, a scheme for controlling congestion in wireless sensor network is proposed. The aim of the proposed method is to reduce congestion by considering the priority of data. In the proposed algorithm, according to the data priority, the packets will be classified. According to type of packet, traffic is redirected to control congestion in the network. Finally, the proposed algorithm is simulated and the result shows that the proposed algorithm improves the number of packet loss, energy consumption and average buffer size rather than the similar algorithm.
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paper_title: Hop‐by‐Hop Congestion Avoidance in wireless sensor networks based on genetic support vector machine

paper_content:

Abstract Congestion in wireless sensor networks causes packet loss, throughput reduction and low energy efficiency. To address this challenge, a transmission rate control method is presented in this article. The strategy calculates buffer occupancy ratio and estimates the congestion degree of the downstream node. Then, it sends this information to the current node. The current node adjusts the transmission rate to tackle the problem of congestion, improving the network throughput by using multi-classification obtained via Support Vector Machines (SVMs). SVM parameters are tuned, using genetic algorithm. Simulations showed that in most cases, the results of the SVM network match the actual data in training and testing phases. Also, simulation results demonstrated that the proposed method not only decreases energy consumption, packet loss and end to end delay in networks, but it also significantly improves throughput and network lifetime under different traffic conditions, especially in heavy traffic areas.
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paper_title: Quality of Information for Wireless Body Area Networks

paper_content:

The Wireless Body Area Networks (WBANs) are a specific group of Wireless Sensor Networks (WSNs) that are used to establish patient monitoring systems which facilitate remote sensing of patients over a long period of time. In this type of system, there is possibility that the information accessible to the health expert at the end point may divert from the original information generated. In some cases, these variations may cause an expert to make a diverse decision from what would have been made specified to the original data. The proposed work contributes toward overcoming this foremost difficulty by defining a quality of information (QoI) metric that helps to preserve the required information. In this paper, we analytically model the QoI as reliability of data generation and reliability of data transfer in WBAN.
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paper_title: Data Aggregation in Wireless Sensor Networks: Previous Research, Current Status and Future Directions

paper_content:

Wireless sensor networks (WSNs) consist of large number of small sized sensor nodes, whose main task is to sense the desired phenomena in a particular region of interest. These networks have large number of applications such as habitat monitoring, disaster management, security and military etc. Sensor nodes are very small in size and have limited processing capability as these nodes have very low battery power. WSNs are also prone to failure, due to low battery power constraint. Data aggregation is an energy efficient technique in WSNs. Due to high node density in sensor networks same data is sensed by many nodes, which results in redundancy. This redundancy can be eliminated by using data aggregation approach while routing packets from source nodes to base station. Researchers still face trouble to select an efficient and appropriate data aggregation technique from the existing literature of WSNs. This research work depicts a broad methodical literature analysis of data aggregation in the area of WSNs in specific. In this survey, standard methodical literature analysis technique is used based on a complete collection of 123 research papers out of large collection of 932 research papers published in 20 foremost workshops, symposiums, conferences and 17 prominent journals. The current status of data aggregation in WSNs is distributed into various categories. Methodical analysis of data aggregation in WSNs is presented which includes techniques, tools, methodology and challenges in data aggregation. The literature covered fifteen types of data aggregation techniques in WSNs. Detailed analysis of this research work will help researchers to find the important characteristics of data aggregation techniques and will also help to select the most suitable technique for data aggregation. Research issues and future research directions have also been suggested in this research literature.
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paper_title: A Survey on Reliability Protocols in Wireless Sensor Networks

paper_content:

Wireless Sensor Network (WSN) applications have become more and more attractive with the miniaturization of circuits and the large variety of sensors. The different application domains, especially critical fields of WSN use, make the reliability of data acquisition and communication a hot research field that must be tackled efficiently. Indeed, the quality of largely used, cheap-cost wireless sensors and their scarce energy supply support these reliability challenges that lead to data loss or corruption. For solving this problem, the conception of a reliability mechanism that detects these shortcomings and recovers to them becomes necessary. In this article, we present a survey on existing reliability protocols conceived especially for WSNs due to their special features. The deep classification and discussion in this study allow for understanding the pros and cons of state-of-the-art works in order to enhance the existing schemes and fill the gaps. We have classified the works according to the required level of reliability, the manner to identify the origins of the lack of reliability, and the control to recover this lack of reliability. Across the discussion along this study, we deduce that the cross-layer design between MAC, routing, and transport layers presents a good concept to efficiently overcome the different reliability holes.
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paper_title: A Survey on Reliability Protocols in Wireless Sensor Networks

paper_content:

Wireless Sensor Network (WSN) applications have become more and more attractive with the miniaturization of circuits and the large variety of sensors. The different application domains, especially critical fields of WSN use, make the reliability of data acquisition and communication a hot research field that must be tackled efficiently. Indeed, the quality of largely used, cheap-cost wireless sensors and their scarce energy supply support these reliability challenges that lead to data loss or corruption. For solving this problem, the conception of a reliability mechanism that detects these shortcomings and recovers to them becomes necessary. In this article, we present a survey on existing reliability protocols conceived especially for WSNs due to their special features. The deep classification and discussion in this study allow for understanding the pros and cons of state-of-the-art works in order to enhance the existing schemes and fill the gaps. We have classified the works according to the required level of reliability, the manner to identify the origins of the lack of reliability, and the control to recover this lack of reliability. Across the discussion along this study, we deduce that the cross-layer design between MAC, routing, and transport layers presents a good concept to efficiently overcome the different reliability holes.
---
paper_title: Quality of Information for Wireless Body Area Networks

paper_content:

The Wireless Body Area Networks (WBANs) are a specific group of Wireless Sensor Networks (WSNs) that are used to establish patient monitoring systems which facilitate remote sensing of patients over a long period of time. In this type of system, there is possibility that the information accessible to the health expert at the end point may divert from the original information generated. In some cases, these variations may cause an expert to make a diverse decision from what would have been made specified to the original data. The proposed work contributes toward overcoming this foremost difficulty by defining a quality of information (QoI) metric that helps to preserve the required information. In this paper, we analytically model the QoI as reliability of data generation and reliability of data transfer in WBAN.
---
paper_title: A Survey on Reliability Protocols in Wireless Sensor Networks

paper_content:

Wireless Sensor Network (WSN) applications have become more and more attractive with the miniaturization of circuits and the large variety of sensors. The different application domains, especially critical fields of WSN use, make the reliability of data acquisition and communication a hot research field that must be tackled efficiently. Indeed, the quality of largely used, cheap-cost wireless sensors and their scarce energy supply support these reliability challenges that lead to data loss or corruption. For solving this problem, the conception of a reliability mechanism that detects these shortcomings and recovers to them becomes necessary. In this article, we present a survey on existing reliability protocols conceived especially for WSNs due to their special features. The deep classification and discussion in this study allow for understanding the pros and cons of state-of-the-art works in order to enhance the existing schemes and fill the gaps. We have classified the works according to the required level of reliability, the manner to identify the origins of the lack of reliability, and the control to recover this lack of reliability. Across the discussion along this study, we deduce that the cross-layer design between MAC, routing, and transport layers presents a good concept to efficiently overcome the different reliability holes.
---
paper_title: A Light-Weight Opportunistic Forwarding Protocol with Optimized Preamble Length for Low-Duty-Cycle Wireless Sensor Networks

paper_content:

In wireless sensor networks, sensed information is expected to be reliably and timely delivered to a sink in an ad-hoc way. However, it is challenging to achieve this goal because of the highly dynamic topology induced from asynchronous duty cycles and temporally and spatially varying link quality among nodes. Currently some opportunistic forwarding protocols have been proposed to address the challenge. However, they involve complicated mechanisms to determine the best forwarder at each hop, which incurs heavy overheads for the resource-constrained nodes. In this paper, we propose a light-weight opportunistic forwarding (LWOF) scheme. Different from other recently proposed opportunistic forwarding schemes, LWOF employs neither historical network information nor a contention process to select a forwarder prior to data transmissions. It confines forwarding candidates to an optimized area, and takes advantage of the preamble in low-power-listening (LPL) MAC protocols and dual-channel communication to forward a packet to a unique downstream node towards the sink with a high probability, without making a forwarding decision prior to data transmission. Under LWOF, we optimize LPL MAC protocol to have a shortened preamble (LWMAC), based on a theoretical analysis on the relationship among preamble length, delivery probability at each hop, node density and sleep duration. Simulation results show that LWOF, along with LWMAC, can achieve relatively good performance in terms of delivery reliability and latency, as a receiver-based opportunistic forwarding protocol, while reducing energy consumption per packet by at least twice.
---
paper_title: A Survey on Reliability Protocols in Wireless Sensor Networks

paper_content:

Wireless Sensor Network (WSN) applications have become more and more attractive with the miniaturization of circuits and the large variety of sensors. The different application domains, especially critical fields of WSN use, make the reliability of data acquisition and communication a hot research field that must be tackled efficiently. Indeed, the quality of largely used, cheap-cost wireless sensors and their scarce energy supply support these reliability challenges that lead to data loss or corruption. For solving this problem, the conception of a reliability mechanism that detects these shortcomings and recovers to them becomes necessary. In this article, we present a survey on existing reliability protocols conceived especially for WSNs due to their special features. The deep classification and discussion in this study allow for understanding the pros and cons of state-of-the-art works in order to enhance the existing schemes and fill the gaps. We have classified the works according to the required level of reliability, the manner to identify the origins of the lack of reliability, and the control to recover this lack of reliability. Across the discussion along this study, we deduce that the cross-layer design between MAC, routing, and transport layers presents a good concept to efficiently overcome the different reliability holes.
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paper_title: RCRT: rate-controlled reliable transport for wireless sensor networks

paper_content:

Emerging high-rate applications (imaging, structural monitoring, acoustic localization) will need to transport large volumes of data concurrently from several sensors. These applications are also loss-intolerant. A key requirement for such applications, then, is a protocol that reliably transport sensor data from many sources to one or more sinks without incurring congestion collapse. In this paper, we discuss RCRT, a rate-controlled reliable transport protocol suitable for constrained sensor nodes. RCRT uses end-to-end explicit loss recovery, but places all the congestion detection and rate adaptation functionality in the sinks. This has two important advantages: efficiency and flexibility. Because sinks make rate allocation decisions, they are able to achieve greater efficiency since they have a more comprehensive view of network behavior. For the same reason, it is possible to alter the rate allocation decisions (for example, from one that ensures that all nodes get the same rate, to one that ensures that nodes get rates in proportion to their demands), without modifying sensor code at all. We evaluate RCRT extensively on a 40-node wireless sensor network testbed and show that RCRT achieves more than twice the rate achieved by a recently proposed interference-aware distributed rate-control protocol, IFRC [23].
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paper_title: Traffic-- -Aware Dynamic Routing to Alleviate Aware Dynamic Routing to Alleviate Aware Dynamic Routing to Alleviate Aware Dynamic Routing to Alleviate Congestion in

paper_content:

Congestion is one of the problems encountered in Wireless Sensor Networks (WSNs). Many algorithms came into existence. They all focused on the solution by reducing the number of packets to be sent by the sender node. This solution is not ideal as it cause decrease in overall throughput in the WSN. This paper focuses on a dynamic aware routing algorithm which is aware of network traffic and probability of congestion. This solves problem of congestion in WSNs through optimal use of idle nodes in the network. Though congestion areas, the algorithm sends less packets while it sends more packets through many paths that contains idle nodes or the nodes that have less load. The proposed algorithm can overcome obstacles created by congestion and provide best throughput performance in WSNs.
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paper_title: Congestion Avoidance Based on Lightweight Buffer Management in Sensor Networks

paper_content:

A wireless sensor network is constrained by computation capability, memory space, communication bandwidth, and above all, energy supply. When a critical event triggers a surge of data generated by the sensors, congestion may occur as data packets converge toward a sink. Congestion causes energy waste, throughput reduction, and information loss. However, the important problem of congestion avoidance in sensor networks is largely open. This paper proposes a congestion-avoidance scheme based on lightweight buffer management. We describe simple yet effective approaches that prevent data packets from overflowing the buffer space of the intermediate sensors. These approaches automatically adapt the sensors' forwarding rates to nearly optimal without causing congestion. We discuss how to implement buffer-based congestion avoidance with different MAC protocols. In particular, for CSMA with implicit ACK, our 1/k-buffer solution prevents hidden terminals from causing congestion. We demonstrate how to maintain near-optimal throughput with a small buffer at each sensor and how to achieve congestion-free load balancing when there are multiple routing paths toward multiple sinks
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paper_title: Explicit and precise rate control for wireless sensor networks

paper_content:

The state of the art congestion control algorithms for wireless sensor networks respond to coarse-grained feedback regarding available capacity in the network with an additive increase multiplicative decrease mechanism to set source rates. Providing precise feedback is challenging in wireless networks because link capacities vary with traffic on interfering links. We address this challenge by applying a receiver capacity model that associates capacities with nodes instead of links, and use it to develop and implement the first explicit and precise distributed rate-based congestion control protocol for wireless sensor networks --- the wireless rate control protocol (WRCP). Apart from congestion control, WRCP has been designed to achieve lexicographic max-min fairness. Through extensive experimental evaluation on the USC Tutornet wireless sensor network testbed, we show that WRCP offers substantial improvements over the state of the art in flow completion times as well as in end-to-end packet delays.
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Title: Congestion Control Techniques in WSNs: A Review

Section 1: INTRODUCTION
Description 1: This section provides a detailed background on wireless sensor networks (WSNs), the significance of congestion control, and the phases involved in congestion control.

Section 2: LITERATURE REVIEW
Description 2: This section discusses various congestion control algorithms for WSNs, their types, and their operational procedures.

Section 3: RCRT
Description 3: This section describes the RCRT (Rate-Controlled Reliable Transport) protocol and its mechanism for resolving congestion.

Section 4: I2MR
Description 4: This section covers the I2MR (Interference and Interdependency Mitigated Routing) protocol, how it controls congestion, and its limitations.

Section 5: TADR
Description 5: This section elaborates on the TADR (Traffic-Aware Dynamic Routing) protocol, including its congestion control mechanism and drawbacks.

Section 6: Buffer-Based Congestion Avoidance Scheme
Description 6: This section outlines the buffer-based congestion avoidance scheme and its effectiveness in load balancing and buffer access.

Section 7: DAIPaS
Description 7: This section explains the DAIPaS (Dynamic Alternative Interference-aware Path Selection) protocol and its strategy for congestion control.

Section 8: Fusion
Description 8: This section describes the Fusion method for congestion control, including its reliance on queue length and hop-by-hop flow control.

Section 9: WRCP (Wireless Rate Control Protocol)
Description 9: This section details the WRCP protocol and its use of a receiver capacity model for fast convergence and fair rate allocation.

Section 10: TRCCIT (Tunable Reliability with Congestion Control for Information Transport)
Description 10: This section discusses the TRCCIT protocol, its hybrid acknowledgment approach, and multipath forwarding for congestion control.

Section 11: DPCC (Decentralized Predictive Congestion Control)
Description 11: This section focuses on the DPCC protocol, including its adaptive flow and back-off interval selection approaches.

Section 12: GMCAR (Grid-based Multipath with Congestion Avoidance Routing)
Description 12: This section introduces the GMCAR protocol, its grid-based methodology, and its effectiveness in reducing delay and increasing network output.

Section 13: TASA (Traffic Aware Scheduling Algorithm)
Description 13: This section elaborates on the TASA protocol, its scheduling approach, and its use of graph theory methods for traffic management.

Section 14: OTF (On-the-Fly Scheduling)
Description 14: This section describes the OTF scheduling approach, including its slot-based interference prevention and traffic load adaptation.

Section 15: PERFORMANCE COMPARISON
Description 15: This section presents a performance comparison of the discussed congestion control schemes, highlighting their operational strategies, strengths, and weaknesses.