LPEDAP: Localized Power Efficient Data Aggregation Tree Protocol for Wireless Sensor Networks
I K. M. Ramya, P. Shanthi · 2014
I. Introduction The design of wireless sensor networks depends on the application requirements. Environmental monitoring is an application where a region is sensed by sensor nodes and the sensed data are gathered at a base station (a sink) where further processing can be performed. The sensor nodes for such applications are usually designed to work in conditions where it may not be possible to recharge or replace the batteries of the nodes. This means that energy is a very precious resource for sensor nodes, and communication overhead is to be minimized. In order to reduce the communication overhead and energy consumption of sensors while gathering, the received data can be combined to reduce message size. A simple way of doing that is aggregating the data. An important problem studied here is finding an energyefficient routing scheme for gathering all data at the sinkperiodically so that the lifetime of the network is prolonged as much as possible. The lifetime can be expressed in terms of rounds where a round is the time period between two sensing activities of sensor nodes. There are several requirements for a routing scheme to be designed for this scenario. First, the algorithm should be distributed since it is extremely energy consuming to calculate the optimum paths in a dynamic network and inform others about the computed paths in a centralized manner. The algorithm must also be scalable. The message and time complexity of computing the routing paths must scale well with increasing number of nodes. Another desirable property is robustness, which means that the routing scheme should be resilient to node and link failures. The scheme should also support new node additions to the network, since not all nodes fail at the same time, and some nodes may need to be replaced. In other words, the routing scheme should be self-healing. The final and possibly the most important requirement for a routing scheme for wireless sensor networks is energy efficiency.