Routing in wireless multimedia sensor networks

Due to distributed nature, dynamic topology and resources constraints of tiny sensing nodes in wireless sensor networks (WSNs), the quality of service (QoS) support is a challenging issue. However, satisfying the stringent QoS requirements is an open problem. QoS aware protocols for WSNs have gained recently considerable attention of the researchers. In this paper, we focus on the QoS satisfaction in WSNs, basics of QoS support in WSNs, and more importantly challenge, requirements of QoS at each layer. Furthermore, we review the QoS protocols and categorize the QoS aware protocols and elaborate their pros and cons. We also discuss the QoS parameters with respect to each protocol performance parameters. A survey and comprehensive discussion on the QoS aware protocols of WSNs are presented, including their strengths and limitations. Finally, we also survey some computational intelligence (CI) techniques and find the basic requirements of such techniques. Moreover, we study these CI techniques in the light of QoS management and tabulate the level of each CI technique for QoS management. The paper is concluded with open research issues.

Quality of Service of Routing Protocols in Wireless Sensor Networks: A Review

Many routing protocols have been proposed for wireless sensor networks. These routing protocols are almost always based on energy efficiency. However, recent advances in complementary metal-oxide semiconductor (CMOS) cameras and small microphones have led to the development of Wireless Multimedia Sensor Networks (WMSN) as a class of wireless sensor networks which pose additional challenges. The transmission of imaging and video data needs routing protocols with both energy efficiency and Quality of Service (QoS) characteristics in order to guarantee the efficient use of the sensor nodes and effective access to the collected data. Also, with integration of real time applications in Wireless Senor Networks (WSNs), the use of QoS routing protocols is not only becoming a significant topic, but is also gaining the attention of researchers. In designing an efficient QoS routing protocol, the reliability and guarantee of end-to-end delay are critical events while conserving energy. Thus, considerable research has been focused on designing energy efficient and robust QoS routing protocols. In this paper, we present a state of the art research work based on real-time QoS routing protocols for WMSNs that have already been proposed. This paper categorizes the real-time QoS routing protocols into probabilistic and deterministic protocols. In addition, both categories are classified into soft and hard real time protocols by highlighting the QoS issues including the limitations and features of each protocol. Furthermore, we have compared the performance of mobility-aware query based real-time QoS routing protocols from each category using Network Simulator-2 (NS2). This paper also focuses on the design challenges and future research directions as well as highlights the characteristics of each QoS routing protocol.

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Real-Time QoS Routing Protocols in Wireless Multimedia Sensor Networks: Study and Analysis

Wireless sensor networks (WSNs) are resource-constrained networks with limited battery power, computation abilities and communication capabilities at the sensor node level. A long-standing need in the area is to reduce energy consumption of the WSN nodes and to extend the network lifetime, along with improving the network reliability and the network quality. Energy-efficient routing protocols can improve the WSN performance, and the algorithms have been explored widely by the researchers. In the majority of the work, sensor nodes have been considered homogeneous in their configuration and capabilities. However, in practical scenarios and with the advent of an era of connected devices, called "Internet of Things," consideration of node heterogeneity in WSN has become inevitable. Nodes' heterogeneity can be exploited constructively in WSN routing algorithms. In the literature, many different heterogeneous WSN scenarios (e.g., energy, computation, link heterogeneities) have been considered and the routing algorithms have been proposed for performance improvement in such scenarios. This paper focuses on the routing concepts for diverse heterogeneous WSNs scenarios and covers the state of the art in the area. The clustering-based approaches for routing decisions are extensively covered under different heterogeneous WSN scenarios. Along with presenting a comprehensive review of the routing algorithms under different varieties of heterogeneous WSNs, the paper also discusses the effects and interdependencies of different heterogeneities in routing decisions and unveils new research directions in the area.

Heterogeneity consideration in wireless sensor networks routing algorithms: a review

In this paper, we propose adaptive multi-objective optimization framework based on non-dominated sorting genetic algorithm-II and learning automata (LA) for coverage and topology control in heterogeneous wireless sensor networks. The multi-objective optimization approach of the proposed framework, called MOOCTC (multi-objective optimization coverage and topology control), can simultaneously optimize several conflicting issues such as number of active sensor nodes, coverage rate of the monitoring area and balanced energy consumption while maintaining the network connectivity. This approach incorporates problem-specific knowledge in its operators to find high-quality solutions. In addition, this approach uses LA to dynamically adapt the crossover and mutation rates without any external control to improve the behavior of the optimization algorithm. Simulation results demonstrate the efficiency of the proposed multi-objective optimization approach in terms of lifetime, coverage and connectivity.

AMOF: adaptive multi-objective optimization framework for coverage and topology control in heterogeneous wireless sensor networks

Due to different requirements in applications, sensors with different capacities are deployed. How to design efficient, reliable and scalable routing protocols in such wireless heterogeneous sensor networks (WHSNs) with intermittent asymmetric links is a challenging task. In this paper, we propose ProHet: a distributed probabilistic routing protocol for WHSNs that utilizes asymmetric links to reach assured delivery rate with low overhead. The ProHet protocol first produces a bidirectional routing abstraction by finding a reverse path for every asymmetric link. Then, it uses a probabilistic strategy to choose forwarding nodes based on historical statistics using local information. Analysis shows that ProHet can achieve assured delivery rate ρ if ρ is set within its upper-bound. Extensive simulations are conducted to verify its efficiency.

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ProHet: A Probabilistic Routing Protocol with Assured Delivery Rate in Wireless Heterogeneous Sensor Networks

In this paper, we propose performance guaranteed routing protocols in asymmetric sensor networks (ASNs) where two end nodes may not use the same path to communicate with each other. ASNs can be caused by hardware devices or environment. Different from most of the existing routing protocols in symmetric sensor networks, because of asymmetry, achieving desired routing performance in ASNs poses significant research challenges. To address these challenges, we first propose a general framework protocol called reverse path (RP) to deal with asymmetric links and then present two efficient routing algorithms LayHet and EgyHet built on RP to satisfy performance requirements. LayHet is a performance guaranteed layer-based routing protocol that embeds the shortest path information and saves energy by minimizing the number of broadcasts and the probability of forwarding. EgyHet is its energy-upgraded version that considers nodes' remaining energy. Simulation results comparing the proposed and existing protocols show that LayHet and EgyHet can reach the desired delivery rate earlier than the existing one and outperform it in terms of average hops, average packet replication overhead, and average control message overhead. In addition, as sensor energy reduces, the performance of LayHet and EgyHet eventually degrades more slowly than that of the existing one.

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Performance Guaranteed Routing Protocols for Asymmetric Sensor Networks

Due to requirements in different applications, sensors with various capacities are deployed. Data routing in such heterogeneous wireless sensor networks (HWSNs) poses challenges. First, the heterogeneous features create asymmetric links in the communication graphs which are not dealt with by conventional routing algorithms using undirected graphs. Second, it is important to provide an assured delivery rate for mission critical applications since sensors communicate with each other through lossy asymmetric links. In this paper, we propose LayHet: a layer-based routing protocol for HWSNs, which takes advantage of the asymmetric links to deliver messages to the sink with an assured delivery rate. Simulation results show that LayHet outperforms previous routing methods in terms of average delivery ratio, average hops, average packet replication and average control message overhead.

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A layer-based routing protocol for heterogeneous wireless sensor networks

Due to different requirements in application environment, wireless heterogeneous sensor networks (WHSNs) formed by sensors with various capacities are built. Data routing in WHSNs poses special challenges: First, it should be redesigned because the existing ones may not be directly used due to asymmetric links caused by diverse sensor transmission ranges. Second, it should guarantee an assured delivery rate because data is routed through lossy links. Third, it should be energy-efficient due to the limitation of sensor batteries and the difficulty of replacing them after deployment. To address these issues, we propose EgyHet: an Energy-saving routing protocol for Heterogeneous sensor networks. EgyHat deals with asymmetric links by establishing reverse paths. It saves energy by taking the shortest path, considering the remaining energy in sensors and reducing the number of forwarding nodes while guarantees an assured delivery rate. Simulation results show that EgyHat can save more energy yet keep the similar delivery ratio and latency to those of the existing routing protocol for WHSNs.

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Zanxun Dai

Papers

ProHet: A Probabilistic Routing Protocol with Assured Delivery Rate in Wireless Heterogeneous Sensor Networks

Performance Guaranteed Routing Protocols for Asymmetric Sensor Networks

A layer-based routing protocol for heterogeneous wireless sensor networks

EgyHet: An energy-saving routing protocol for wireless heterogeneous sensor networks