Abstract Wireless Sensor Networks (WSNs) is an emerging area belonging to the wireless technologies that has recently developed interest among the industry and academic researchers. It consists of small battery powered sensors, where failures of sensor nodes and disruption of connectivity are regular phenomena. Therefore, energy consumption and network lifetime are important issues. Clustering is one of the most efficient algorithms... Wireless Sensor Networks (WSNs) is an emerging area belonging to the wireless technologies that has recently developed interest among the industry and academic researchers. It consists of small battery powered sensors, where failures of sensor nodes and disruption of connectivity are regular phenomena. Therefore, energy consumption and network lifetime are important issues. Clustering is one of the most efficient algorithms for selforganization. The most important point in this algorithm is cluster head selection because a good clustering guarantees stability, energy efficiency and load balancing in the network. In this paper we propose a new approach called EPC (Enhanced passive clustering algorithm), which evenly distributes the energy dissipation among the sensor nodes to maximize the network lifetime. This is achieved by using residual energy, number of neighbors and distance between nodes in the selection of nodes clusterheads and election of clusterhead backup. The simulation analysis of the EPC over the existing system shows the improvement in performance attained through the proposed passive clustering protocol. It reveals that the approach proposed algorithm improves significantly and particularly the network lifetime. Read More Read Less

Abstract The Wireless Mesh Network (WMN) is a highly capable technology that can offer low-cost and easydeployable network connectivity to both small-size community networks and large-scale metropolitan networks. As a key emerging technology to provide the next generation broadband networking, WMN combines the advantages of both mobile ad hoc network (MANET) and traditional fixed network, attracting significant industrial and academic attentions.... The Wireless Mesh Network (WMN) is a highly capable technology that can offer low-cost and easydeployable network connectivity to both small-size community networks and large-scale metropolitan networks. As a key emerging technology to provide the next generation broadband networking, WMN combines the advantages of both mobile ad hoc network (MANET) and traditional fixed network, attracting significant industrial and academic attentions. We present a new metric for routing in multi-radio, multihop wireless networks. We focus on wireless networks with stationary nodes, such as community wireless networks. The goal of the metric is to choose a high-throughput path between a source and a destination. Our metric assigns weights to individual links based on the Expected Transmission Time (ETT) of a packet over the link. The ETT is a function of the loss rate and the bandwidth of the link. Read More Read Less

Abstract Next generation networks will combine various access technologies to enable users to roam freely from one access network to another which is referred as Vertical handovers. Vertical handovers mobility management in next generation all-IP networks is the key factor that determines vertical handovers (HO) performance. Mobility management is generally based on mobility protocols that perform the handovers either horizontally (within... Next generation networks will combine various access technologies to enable users to roam freely from one access network to another which is referred as Vertical handovers. Vertical handovers mobility management in next generation all-IP networks is the key factor that determines vertical handovers (HO) performance. Mobility management is generally based on mobility protocols that perform the handovers either horizontally (within the same access network) or vertically (between different access technologies). In this context, many solutions were proposed to provide seamless vertical handovers between WLAN and WiMax networks. These solutions aimed to perform the HO with minimum QoS degradation based on either the coupling architecture method, the mobility management protocol or the handover decision process. Our solution is based on the handover decision process that will make use of the emerging WiMax technology in order to guide the vertical handover to the suitable destination network in terms of network availability and service provisioning. As users in WLAN networks may initiate handovers for better connectivity, WiMax network will be considered as the default destination network that will guide the handover according to the HO context requirements. Our approach consists of adding a context Adjustment Unit CAU to the WiMax Connectivity Service Network CSN to guide the handover, according to the HO context requirements, either horizontally or vertically. Read More Read Less

Abstract In recent years there has been a paradigm shift from voice centric to data centric wireless communication with data transmission greatly exceeding voice transmission in most developed markets. This phenomenon has caused anxiety in the operators worldwide to enhance the capacity of their wireless networks. Coupled with the demand for high data rate wireless transmission, the increased capacity requirement has... In recent years there has been a paradigm shift from voice centric to data centric wireless communication with data transmission greatly exceeding voice transmission in most developed markets. This phenomenon has caused anxiety in the operators worldwide to enhance the capacity of their wireless networks. Coupled with the demand for high data rate wireless transmission, the increased capacity requirement has prompted the operators and researchers to explore various options to achieve this end. The transition from 3G (Third generation) to 4G (Fourth generation) is defined by the need for increased data rate. Multiple -input multiple-output (MIMO) wireless technology in combination with orthogonal frequency division multiplexing (OFDM) is an attractive air-interface solution to meet the demands of 4G networks. MIMO provides a capacity advantage over multi-path channel while OFDM is particularly suited for high data rate wireless transmission which is also resistant to multipath fading. This paper provides an overview of the basics of MIMO-OFDM technology and focuses on performance in Fourth generation (4G) standard like Long Term Evolution (LTE). The challenges and potential research areas are proposed. Read More Read Less

Abstract In Wireless Sensor Networks (WSNs) where nodes are energy constrained, power conservation is an important issue. This paper proposes a novel approach for energy efficient clustering technique using the fuzzy logic method. The clustering technique has been proven effective to optimize the energy consumed by the nodes of a wirelesssensor network during data routing. The establishment of clusters, the cluster-heads... In Wireless Sensor Networks (WSNs) where nodes are energy constrained, power conservation is an important issue. This paper proposes a novel approach for energy efficient clustering technique using the fuzzy logic method. The clustering technique has been proven effective to optimize the energy consumed by the nodes of a wirelesssensor network during data routing. The establishment of clusters, the cluster-heads choice, and the manner in which the clusters evolve over time are difficult tasks that greatly affect the quality of the routing protocol. The objective of this protocol is increasing the lifetime of sensor nodes by re-clustering the whole network repeatedly using on a fuzzy re-clustering system model. Read More Read Less