Comparative analysis of contention oriented power saving based medium access control Protocols for wireless sensor networks

Wireless sensor networks are an emerging technology for low-cost that are becoming involved in almost every field of life, due to the advancement in wireless technologies and reductions in size. Idle listening is disastrous in WSNs based on the fact that nodes in this mode consume the same magnitude of power as in receiving. Overhearing means that nodes decode packets are destined to others. Collisions result in corrupted packets and the following MAC layer retransmissions consume extra energy. From the network perspective, channel contention is a serious problem in WSNs resulting in collisions, re-transmissions. In this paper, we focus on the MAC layer problem with contention protocols oriented saving energy and latency. We have compared the existing contention-based protocols: IEEE802.11/802.15.4, S-MAC, T-MAC and OB-MAC protocols. We simulated and evaluated the performance of existing protocols using the NS-2 simulator. Evaluations show that the optimized OB-MAC achieved considerable improvement in energy and latency.