Dimitrios D. Vergados

Energy-Efficient Routing Protocols in Wireless Sensor Networks: A Survey

The distributed nature and dynamic topology of Wireless Sensor Networks (WSNs) introduces very special requirements in routing protocols that should be met. The most important feature of a routing protocol, in order to be efficient for WSNs, is the energy consumption and the extension of the networks lifetime. During the recent years, many energy efficient routing protocols have been proposed for WSNs. In this paper, energy efficient routing protocols are classified into four main schemes: Network Structure, Communication Model, Topology Based and Reliable Routing. The routing protocols belonging to the first category can be further classified as flat or hierarchical. The routing protocols belonging to the second category can be further classified as Query-based or Coherent and non-coherent-based or Negotiation-based. The routing protocols belonging to the third category can be further classified as Location-based or Mobile Agent-based. The routing protocols belonging to the fourth category can be further classified as QoS-based or Multipath-based. Then, an analytical survey on energy efficient routing protocols for WSNs is provided. In this paper, the classification initially proposed by Al-Karaki, is expanded, in order to enhance all the proposed papers since 2004 and to better describe which issues/operations in each protocol illustrate/enhance the energy-efficiency issues.

A survey on power control issues in wireless sensor networks

ith the proliferation in sensor nodes and the development in wireless communication technologies, Wireless Sensor Networks (WSNs) have gained worldwide attention in recent years. They facilitate monitoring and controlling of physical environments from remote locations with great accuracy and represent a significant improvement over wired sensor networks. WSNs are employed in a vast variety of fields, such as: environmental monitoring (e.g., temperature, humidity), monitoring disaster areas providing relief, file exchange, conferencing, home, health (monitoring patients and assisting disabled patients), commercial applications including managing inventory and monitoring product quality and military purposes. Their function is to collect and disseminate critical data, while their position does need to be engineered or predetermined, in contrast to the wired ones. This allows random deployment in inaccessible terrains or disaster relief operations. On the other hand, this also means that WSN protocols and algorithms must possess self-organizing capabilities [1]. Realization of the wireless sensor network applications requires wireless ad-hoc networking techniques. Although a great number of protocols and algorithms have been proposed for wireless ad-hoc networks, they are not well-suited to the unique features and application requirements of WSNs for the following reasons: • The topology of a WSN changes very frequently. • The number of sensor nodes in a WSN can be several orders of magnitude higher than the number of sensor nodes in a wireless ad-hoc network. • Sensor nodes are densely deployed in a sensor field • Sensor nodes mainly use a broadcast communication paradigm, whereas most wireless ad-hoc networks are based on point-to-point communications. • Sensor nodes may not have global identification due to their large amount of overhead and large number of sensors in the WSN. • Sensor nodes are limited in power, computational capacity and memory. This last requirement is the primary limitation of the WSNs. Their survivability, as it has already been mentioned, depends on power control and power management of the consumed energy, as well as on network connectivity. Considerable research has been focused at overcoming the deficiencies of energy consumption of the sensor nodes, guaranteeing the sensor networks existence and increasing the sensor networks lifetime in such energy-constrained environments through more power control schemes regarding resource allocation, routing and low-energy consumption. This survey attempts to provide an overview of these issues as well as the solutions proposed in recent literature. ABSTRACT A Wireless Sensor Network (WSN) is actually composed of a large number of very small …

Energy efficiency in wireless sensor networks using sleep mode TDMA scheduling

Power saving is a very critical issue in energy-constrained wireless sensor networks. Many schemes can be found in the literature, which have significant contributions in energy conservation. However, these schemes do not concentrate on reducing the end-to-end packet delay while at the same time retaining the energy-saving capability. Since a long delay can be harmful for either large or small wireless sensor networks, this paper proposes a TDMA-based scheduling scheme that balances energy-saving and end-to-end delay. This balance is achieved by an appropriate scheduling of the wakeup intervals, to allow data packets to be delayed by only one sleep interval for the end-to-end transmission from the sensors to the gateway. The proposed scheme achieves the reduction of the end-to-end delay caused by the sleep mode operation while at the same time it maximizes the energy savings.

Energy Efficient Routing in Wireless Sensor Networks Through Balanced Clustering

The wide utilization of Wireless Sensor Networks (WSNs) is obstructed by the severely limited energy constraints of the individual sensor nodes. This is the reason why a large part of the research in WSNs focuses on the development of energy efficient routing protocols. In this paper, a new protocol called Equalized Cluster Head Election Routing Protocol (ECHERP), which pursues energy conservation through balanced clustering, is proposed. ECHERP models the network as a linear system and, using the Gaussian elimination algorithm, calculates the combinations of nodes that can be chosen as cluster heads in order to extend the network lifetime. The performance evaluation of ECHERP is carried out through simulation tests, which evince the effectiveness of this protocol in terms of network energy efficiency when compared against other well-known protocols.

A Survey on the Successive Interference Cancellation Performance for Single-Antenna and Multiple-Antenna OFDM Systems

Interference plays a crucial role for performance degradation in communication networks nowadays. An appealing approach to interference avoidance is the Interference Cancellation (IC) methodology. Particularly, the Successive IC (SIC) method represents the most effective IC-based reception technique in terms of Bit-Error-Rate (BER) performance and, thus, yielding to the overall system robustness. Moreover, SIC in conjunction with Orthogonal Frequency Division Multiplexing (OFDM), in the context of SIC-OFDM, is shown to approach the Shannon capacity when single-antenna infrastructures are applied while this capacity limit can be further extended with the aid of multiple antennas. Recently, SIC-based reception has studied for Orthogonal Frequency and Code Division Multiplexing or (spread-OFDM systems), namely OFCDM. Such systems provide extremely high error resilience and robustness, especially in multi-user environments. In this paper, we present a comprehensive survey on the performance of SIC for single- and multiple-antenna OFDM and spread OFDM (OFCDM) systems. Thereby, we focus on all the possible OFDM formats that have been developed so far. We study the performance of SIC by examining closely two major aspects, namely the BER performance and the computational complexity of the reception process, thus striving for the provision and optimization of SIC. Our main objective is to point out the state-of-the-art on research activity for SIC-OF(C)DM systems, applied on a variety of well-known network implementations, such as cellular, ad hoc and infrastructure-based platforms. Furthermore, we introduce a Performance-Complexity Tradeoff (PCT) in order to indicate the contribution of the approaches studied in this paper. Finally, we provide analytical performance comparison tables regarding to the surveyed techniques with respect to the PCT level.

A Survey of Pricing Schemes in Wireless Networks

The expansion of new technologies is expected to offer economic growth in the wired and wireless technological networking environment, while at the same time, it will offer a wide variety of services and give the possibility for utilizing technologies for the benefit of many subscribers. The Pricing Schemes are designed to offer profitable business to the Wireless Service Providers (WSPs), as well as, to create favorable services for the mobile subscribers and eventually to get charged according to their services usage. In this paper, the Pricing Schemes are classified, based on their ability to adapt to the needs of the WSPs and their subscribers during the entire service period, into Static-based Pricing and Dynamic-based Pricing Schemes. The Pricing Schemes are also analyzed in detail and are further classified according to the factors involved in the price calculation of a service, i.e. the Service Level Agreement (SLA), the subscription type, the negotiation capabilities between WSPs and their subscribers, the network capacity, the available bandwidth and frequency spectrum, the network hops, and the Base Stations (BSs). The affected elements by the pricing network are also discussed, together with the performance evaluation of the presented pricing schemes.

Power Conservation through Energy Efficient Routing in Wireless Sensor Networks

The power awareness issue is the primary concern within the domain of Wireless Sensor Networks (WSNs). Most power dissipation ocurrs during communication, thus routing protocols in WSNs mainly aim at power conservation. Moreover, a routing protocol should be scalable, so that its effectiveness does not degrade as the network size increases. In response to these issues, this work describes the development of an efficient routing protocol, named SHPER (Scaling Hierarchical Power Efficient Routing).

An access network selection algorithm for heterogeneous wireless environments

Ubiquitous service delivery requires the selection of the optimal access network in a heterogeneous wireless environment. However, since the selection of an access network in such an environment depends on several parameters with different relative importance (such as the network and the application characteristics, the user preferences, the service cost), it is a difficult task to be achieved. In this paper, an effective access network selection algorithm for heterogeneous wireless networks is proposed that combines two Multi Attribute Decision Making (MADM) methods, the Analytic Hierarchy Process (AHP) method and the Total Order Preference by Similarity to the Ideal Solution (TOPSIS) method. More specifically, the AHP method is used to determine weights of the criteria and the TOPSIS method is used to obtain the final access network ranking.

Network selection in a WiMAX–WiFi environment

Abstract The tremendous growth of wireless technologies has introduced the potential of continuous service adaptation to the users’ needs by giving them the ability to be able to select and access the proper network based on different criteria. Moreover, next generation wireless networks have been designed to provide support for multimedia services, with different traffic characteristics and different Quality of Service (QoS) guarantees. However, the expansion of Wireless Local Area Networks (WLANs) and Worldwide Interoperability for Microwave Access (WiMAX) networks poses new research era in the decision of the access network selection. In this paper, the existing access network selection schemes are classified into three categories: the network-centric, the user-centric and the collaborative schemes, and are analyzed respectively. Moreover, we propose a multicriteria access network selection algorithm applied in a WiMAX–WLAN environment, in order to facilitate the provision of high quality services and at the same time to satisfy different types of user Service Level Agreements (SLAs).

QoS-aware TDMA for end-to-end traffic scheduling in ad hoc networks

The proliferation of low-cost broadband air interfaces has paved the way to the introduction of high-definition multimedia services in mobile and wireless networks. The cost for network resources utilization, when provisioning such services, will play a prominent role in their commercial success, since the more spare resources that can be used, the more cheaply the services can be delivered to the end users. In the context of promoting the role of ad hoc networks as service platforms for high quality multimedia applications, this article first discusses and classifies a set of issues involved in quality of service (QoS) provisioning in ad hoc networks and then presents a congestion-free TDMA algorithm for end-to-end network resources assignment via an optimized mechanism that relies on capacity requests and grants. The article also illustrates a method for invoking this algorithm to achieve efficient end-to-end QoS provisioning and concludes by showing the superiority of the proposed algorithm, as compared to other recently proposed TDMA scheduling algorithms