Wireless Sensor Networks (WSNs) are among the most emerging technologies, thanks to their great capabilities and their ever growing range of applications. However, the lifetime of WSNs is extremely restricted due to the delimited energy capacity of their sensor nodes. This is why energy conservation is considered as the most important research concern for WSNs. Radio communication is the utmost energy consuming function in a WSN. Thus, energy efficient routing is necessitated to save energy and thus prolong the lifetime of WSNs. For this reason, numerous protocols for energy efficient routing in WSNs have been proposed. This article offers an analytical and up to date survey on the protocols of this kind. The classic and modern protocols presented are categorized, depending on i) how the network is structured, ii) how data are exchanged, iii) whether location information is or not used, and iv) whether Quality of Service (QoS) or multiple paths are or not supported. In each distinct category, protocols are both described and compared in terms of specific performance metrics, while their advantages and disadvantages are discussed. Finally, the study findings are discussed, concluding remarks are drawn, and open research issues are indicated.

https://www.mdpi.com/1999-4893/13/3/72/pdf

Energy Efficient Routing in Wireless Sensor Networks: A Comprehensive Survey

Connectivity preserving localized coverage algorithm for area monitoring using wireless sensor networks

Reputation-based role assignment for role-based access control in wireless sensor networks

Resource limited networks have various applications in our daily life. However, a challenging issue associated with these networks is a uniform load balancing strategy to prolong their lifespan. In literature, various schemes try to improve the scalability and reliability of the networks, but majority of these approaches assume homogeneous networks. Moreover, most of the technique uses distance, residual energy and hop count values to balance the energy consumption of participating nodes and prolong the network lifetime. Therefore, an energy efficient load balancing scheme for heterogeneous wireless sensor networks (WSNs) need to be developed. In this article, an energy gauge node (EGN) based communication infrastructure is presented to develop a uniform load balancing strategy for resource-limited networks. EGN measures the residual energy of the participating nodes i.e., C
 i
 ∈ Network. Moreover, EGN nodes advertise hop selection information in the network which is used by ordinary nodes to update their routing tables. Likewise, ordinary nodes use this information to uni-cast its collected data to the destination. EGN nodes work on built-in configuration to categorize their neighboring nodes such as powerful, normal and critical energy categories. EGN uses the strength of packet reply (SPR) and round trip time (RTT) values to measure the neighboring node's residual energy (E
 r
) and those node(s) which have a maximum E
 r
 values are advertised as reliable paths for communication. Furthermore, EGN transmits a route request (RREQ) in the network and receives route reply (RREP) from every node reside in its closed proximity which is used to compute the E
 r
 energy values of the neighboring node(s). If E
 r
 value of a neighboring node is less than the defined category threshold value then this node is advertised as non-available for communication as a relaying node. The simulation results show that our proposed scheme surpasses the existing schemes in terms of lifespan of individual nodes, throughput, packet loss ratio (PLR), latency, communication costs and computation costs, etc,. Moreover, our proposed scheme prolongs the lifespan of WSNs and as well as an individual node against exiting schemes in the operational environment.

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An Efficient Load Balancing Scheme of Energy Gauge Nodes to Maximize the Lifespan of Constraint Oriented Networks

A cyber-physical system (CPS) consists of a group of interlinked networked objects. CPSs are characteristically different from the traditional internetworked systems (e.g., Internet) due to the operating environment and their applications, which impose high reliability constraints on them. One of the fundamental considerations for enabling this technology is the medium access control (MAC). The traditional IEEE 802.11-based MAC layer solutions need to be revamped. In order to increase the efficiency of data transmission, we introduce a new approach, which argues the replacement of the traditional backoff algorithm of 802.11. The proposed approach attempts to address some of the obligations posed by CPS networks. At the core of the proposed solution is the introduction of the adaptability factor to the traditional backoff procedure, which can help CPS networks operate under diverse environmental conditions. In order to survive the high degrees of dynamism of these networks, each of the nodes is equipped with a learning automaton, which adapts to the changing environment and provides the node with the most optimized value. The consistent outperformance of the proposed approach when compared with similar existing approaches under different simulation scenarios exhibits its efficacy. The critical parameters, such as packet delivery ratio and delay, are improved by up to 40% and 27%, respectively, over the traditional protocols.

Efficient Medium Access Control for Cyber–Physical Systems With Heterogeneous Networks

Wireless Sensor Networks (WSN) have nodes that are small in size and are powered by small batteries having very limited amount of energy. In most applications of WSN, the nodes in the network remain inactive for long periods of time, and intermittently they become active on sensing any change in the environment. The data sensed by the different nodes are sent to the sink node. In contrast to other infrastructure-based wireless networks, higher throughput, lower latency and per-node fairness in WSN are imperative, but their importance is subdued when compared to energy consumption. In this work, we have regarded the amount of energy consumption in the nodes to be of primary concern, while throughput and latency in the network to be secondary. We have proposed a protocol for energy-efficient adaptive listen for medium access control in WSN. Our protocol adaptively changes the slot-time, which is the time of each slot in the contention window. This correspondingly changes the cycle-time, which is the sum of the listen-time and the sleep-time of the sensors, while keeping the duty-cycle, which is the ratio between the listen-time and the cycle-time, constant. Using simulation experiments, we evaluated the performance of the proposed protocol, compared with the popular Sensor Medium Access Control (SMAC) (Ye et al. IEEE/ACM Trans Netw 12(3):493---506, 39) protocol. The results we obtained show a prominent decrease in the energy consumption at the nodes in the proposed protocol over the existing SMAC protocol, at the cost of decreasing the throughput and increasing the latency in the network. Although such an observation is not perfectly what is ideally desired, given the very limited amount of energy with which the nodes in a WSN operate, we advocate that increasing the energy efficiency of the nodes, thereby increasing the network lifetime in WSN, is a more important concern compared to throughput and latency. Additionally, similar observations relating energy efficiency, network lifetime, throughput and latency exist in many other existing protocols, including the popular SMAC protocol (Ye et al. IEEE/ACM Trans Netw 12(3):493---506, 39).

Adaptive listen for energy-efficient medium access control in wireless sensor networks

The sensor nodes in a Wireless Sensor Network (WSN) are typically characterized by limited power supply, low bandwidth, small memory sizes and limited energy, leading to a very demanding environment to provide security. In this paper, we propose a protocol named Fuzzy Logic-based Energy Efficient Packet Loss Preventive Routing Protocol (FEEPRP) that adopts a routing algorithm which imparts security in terms of avoiding malicious nodes and prevent data loss as well as constrains the utilization of excess energy. FEEPRP does not absorb the idea of any kind of digital signatures or Message Authentication Code (MAC) for authentication, as the latter produce high communication overhead. It exploits the fuzzy decision making model to avail an energy-efficient secure route to the destination. Simulation analysis shows that the FEEPRP helps to impart effective security to the network while maintaining an improved network performance level.

Debashish Mohanta

Papers

Adaptive listen for energy-efficient medium access control in wireless sensor networks

A Fuzzy logic-based Energy Efficient Packet Loss Preventive Routing Protocol