Recent, advances in wireless networks and electronics have led to the emergence of Wireless Sensor networks (WSNs). WSNs have been considered as one of the most important technologies that can change the future. These networks consist of small battery–powered motes with limited computation and radio communication capabilities. Each sensor in a sensor network consists of three subsystems: the se...

Cognitive radio wireless sensor networks (CR-WSNs) have attracted a great deal of attention recently due to the emerging spectrum scarcity issue. This work attempts to provide a detailed analysis of the role of node clustering in CR-WSNs. We outline the objectives, requirements, and advantages of node clustering in CR-WSNs. We describe how a CR-WSN with node clustering differs from conventional...

IEEE 802.15.4 is a new standard uniquely designed for low rate wireless sensor networks(WSNs). It targets low data rate, low power consumption and low cost wireless networking, and offers device level wireless connectivity. In this paper, the general coordinated sleeping algorithm and the traffic-adaptive algorithm are combined in IEEE 802.15.4 MAC protocol to achieve high energy efficiency and...

in recent years wireless sensor networks have attracted researchers' attention due to vast applications. one of the most prominent issues regarding these networks is coverage which is considered as a quality of service parameter. in this study, we try to address energy shortage in wsns through finding a set of optimal coverage nodes in a specific environment. this is performed utilizing effecti...

Due to wireless nature and hostile environment, providing of security is a critical and vital task in wireless sensor networks (WSNs). It is known that key management is an integral part of a secure network. Unfortunately, in most of the previous methods, security is compromised in favor of reducing energy consumption. Consequently, they lack perfect resilience and are not fit for applications ...

Wireless sensor network is a collection of large number of low cost resource constraint sensor nodes that communicates using wireless medium. Sensor nodes are resource constrained in memory, sensing, communication capability, and battery power. Data communication between nodes consumes a large portion of the total energy consumption of the WSNs. One of the solutions to reduce number of bits tra...

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. Energy conservation is one of the major important issues in wireless sensor networks. In WSN communication is based on battery...

Wireless sensor networks (WSNs) consist of sensor nodes. These networks have huge application in habitat monitoring, disaster management, security and military, etc. Wireless sensor nodes are very small in size and have limited processing capability and very low battery power. This restriction of low battery power makes the sensor network prone to failure. Data aggregation is a very crucial tec...

In Wireless Sensor Networks (WSNs) and Wireless Personal Area Networks (WPANs), IEEE802.15.4 [1] has emerged as one of the most promising radio specifications for physical layer and medium access control, guaranteeing low rate and low power communication independent of infrastructure. To utilize the collected information under WSNs, the data typically pass through gateways or sinks. Simultaneou...

In recent years, energy efficiency and data aggregation is a major concern in many applications of Wireless Sensor Networks (WSNs).WSNs, consists of a large number of sensor nodes. Each sensor node senses environmental phenomenon and sends the report to a sink node. Since the sensor nodes are powered by limited power batteries, so energy efficiency is a major challenge in WSNs applications. For...