A Study on Energy-Balanced Transmission policies for Maximize Network Lifetime in Wireless Sensor Networks

Unbalanced energy consumption is an inherent problem in wireless sensor networks characterized by multihop routing and many-to-one traffic pattern, and this uneven energy dissipation can significantly reduce network lifetime. Existing transmission policies, however, cause an extremely unbalanced energy usage that contributes to early demise of some sensors reducing overall network’s lifetime drastically. In this paper, we study the problem of maximizing network lifetime through balancing energy consumption for uniformly deployed data-gathering sensor networks. Considering cocentric rings around the sink, we decompose the transmission distance of traditional multihop scheme into two parts: ring thickness and hop size, analyze the traffic and energy usage distribution among sensors and determine how energy usage varies and critical ring shifts with hop size. we use three transmission policies, namely, fixed hop size (FHS), synchronous variable hop size (SVHS), and asynchronous variable hop size (AVHS) transmissions. These transmission policies differ in terms of their degree of flexibility in using variable transmission ranges and their associated duty cycles among sensor nodes. Moreover, we presented distributed heuristics for SVHS and AVHS transmissions, namely, heuristic-SVHS (H-SVHS) and heuristic-AVHS (H-AVHS), respectively, by exploiting the inherent energy usage distribution pattern among sensors for varying hop sizes. Performance analysis shows substantial improvement of network lifetime over the existing SH, MH, and their hybrid transmission policies irrespective of network parameters. Energy usage is more uniformly distributed over the rings and critical energy per data cycle is reduced significantly in our policies.