Energy Level Performance of Packet Delivery Schemes in Wireless Sensor Networks over Fading Channels

Energy level performance of three packet delivery schemes in a Wireless Sensor Networks (WSNs) over fading channels is evaluated. Effects of two short term fading such as Rayleigh and Rician on packet delivery schemes are evaluated. Three different information delivery mechanisms are considered using regenerative relays with or without error correction capability. In all the three schemes, message packet is sent on hop-by-hop basis. In scheme I, message is corrected for error at every hop while in the other two schemes; message is corrected at the destination. Energy consumption for successful delivery of a data packet for each mechanism is evaluated and compared under several conditions of node density, bit rate and transmit power. Energy efficiencies of different retransmission schemes are evaluated. Further an optimal packet length based on energy efficiency is derived in each transmission scheme. Effects of different level of severity of Rician fading on energy efficiency and energy consumption are also investigated. Impact of optimal packet size on total energy expenditure is analyzed. KeywordsWireless Sensor Networks (WSNs); Rician Fading; Rayleigh Fading; Bit Error Rate (BER); ARQ; Energy Efficiency.