MAC Layer Label Switching for Wireless Sensor Networks

Energy efficiency is a critical issue for a MAC protocol in sensor networks. Thus much effort has been paid on research about the sleeping mode of MAC protocol. However, we found out that significant amount of energy is wasted when a data packet received by MAC is transferred to the network layer to get the next hop address by searching the routing table and then the packet is transferred back to the same MAC interface again. We present a new MAC layer label switching(MLLS) protocol based on IEEE 802.11 with minimum modification to it. The protocol is built over hierarchical sensor networks. By this protocol, data forwarding in networks is basically performed over MAC layer and routes are carried by the four address fields in IEEE 802.11 so that we can save significant processing time in terms of route table search time and data moving time. Our simulation results show that MLLS achieves a significant processing delay and thus end-to-end delay improvement. This protocol can also adopt sleep mode scheme such as duty-cycle approach to be more power efficient.