Title: Optimal transmit power and packet size in wireless sensor networks in lognormal shadowed environment
Authors: Arnab Nandi; Sumit Kundu
Addresses: Department of Electronics and Communication Engineering, National Institute of Technology Durgapur, Durgapur 713209, India. ' Department of Electronics and Communication Engineering, National Institute of Technology Durgapur, Durgapur 713209, India
Abstract: In this paper, an optimum packet based transmission scheme for WSN (Wireless Sensor Network) where packet size is varied depending on the node density and channel condition is discussed. A WSN based on a square grid topology is investigated. This optimum size packet yields highest energy efficiency for a particular network condition. Optimum packet length is evaluated under several network conditions in presence of shadowing. Impact of severity of shadowing on optimal packet size is also investigated. Energy expenditure for optimum packet based scheme is compared with that of an arbitrary fixed packet size based transmission. Further impact of severity of fading on energy consumption is also studied. An infinite ARQ (Automatic Repeat reQuest) scheme between adjacent nodes has been considered to successfully deliver a file. Optimal transmit power is also derived for the above network. Optimal transmit power is the minimum transmit power used by all nodes to guarantee network connectivity with a prefixed BER (Bit Error Rate) threshold. Further impacts of lognormal shadowing on optimal transmit power, route BER and energy efficiency are studied for such WSN.
Keywords: WSNs; wireless sensor networks; BER; bit error rate; optimal transmit power; optimal packet size; ARQ; automatic repeat request; shadowing; energy efficiency.
International Journal of Sensor Networks, 2012 Vol.11 No.2, pp.81 - 89
Received: 11 Nov 2010
Accepted: 13 Jul 2011
Published online: 19 Mar 2012 *