Wireless sensor networks (WSNs) are composed of many homogeneous or heterogeneous sensor nodes with limited resources. A sensor node is comprised of three components: a sensor, a processor and a wireless communication device. A sensor of nodes detect a change in surroundings, a processor processes sensing data collected from neighbour nodes or own environmental information, and a wireless commu...

A secure scheme for heterogeneous wireless sensor networks is presented. The wireless sensor networks have some sensor nodes and heterogeneous sensor nodes that have greater power and transmission capability than other nodes have. All kinds of sensor nodes are evenly distributed respectively in entire sensing area that is divided into a number of same cells and logical groups evenly. The pairwi...

Provision of energy to wireless sensor networks is crucial for their sustainable operation. Sensor nodes are typically equipped with batteries as their operating energy sources. However, when the sensor nodes are sited in almost inaccessible locations, replacing their batteries incurs high maintenance cost. Under such conditions, wireless charging of sensor nodes by a mobile charger with an ant...

The limited resource of sensor nodes requires lightweight and efficient schemes to synchronize clocks on different nodes. Network-wide time synchronization is an even more challenging problem because a sensor network usually has a large number of sensor nodes. In this paper, we consider the problem of synchronizing the clocks of all nodes in large scale sensor networks. Making all sensor nodes ...

Location information of sensor nodes in wireless sensor networks (WSNs) is very important, for it makes information that is collected and reported by the sensor nodes spatially meaningful for applications. Since most current sensor localization schemes rely on location information that is provided by beacon nodes for the regular sensor nodes to locate themselves, the accuracy of localization de...

A wireless sensor network consists of small sensor nodes each of which comprises of a processing device, small amount of memory, battery and radio transceiver for communication. The sensor nodes are autonomous and spatially distributed in an area of investigation. Certain applications and protocols of wireless sensor networks require that the sensor nodes should be aware of their position relat...

Sensor technology has matured enough to be used in any type of environment. The appearance of new physical sensors has increased the range of environmental parameters for gathering data. Because of the huge amount of unexploited resources in the ocean environment, there is a need of new research in the field of sensors and sensor networks. This special issue is focused on collecting recent adva...

Wireless sensor networks have become a hot research area due to their numerous applications in monitoring inaccessible areas, which are difficult to be monitored by conventional methods. A large number of wireless sensor network based applications are location dependent, where the sensed data is meaningless without accurate location of its origin. Some of these applications require highly accur...

Wireless sensor networks are event-based systems based on the collaboration of several micro sensor nodes. Due to the limited supply of power at sensor nodes, power efficient configuration of wireless sensor network has become a major design goal to improve the lifetime of the network. The cluster-based wireless sensor network can enhance the whole network lifetime by aggregating the collected ...

Localization in an ad hoc mobile sensor network is an important requirement as most of the applications that use sensor data require sensor location information to complete the processing. A typical sensor network has over hundred to thousand sensor nodes, and considering the size and cost of a sensor, using only GPS for localization is not very attractive. The mobility of sensor nodes could le...