Energy utilization of HTAP under specific node placements in Wireless Sensor Networks

Energy utilization is a challenging task that is being encountered in low-powered Wireless Sensor Networks (WSNs) when designing an algorithm, protocol or hardware. Congestion is a factor that can affect a network´s lifetime (and energy utilization), since it usually leads to packet drops or collisions in the medium followed by possible retransmissions. Forwarding data packets through alternative paths is a way to counter congestion in WSNs. Proper node placement is essential to ensure good sensing coverage and communication connectivity. Node placement could also be affected by the need to create multiple routes to the sink; therefore, it can be proven vital for the improvement of energy utilization performance of this type of congestion control algorithms. In this paper we evaluate the energy utilization performance of HTAP (Hierarchical Tree Alternative Path) a congestion control and avoidance algorithm whose operation is based on a multipath routing scheme. HTAP energy utilization is evaluated under specific node placements and in correlation with a comparable routing scheme (Directed Diffusion). Through simulations, conclusions are extracted, suggesting node placements that assist in uniform and efficient energy utilization in WSNs.