The Chained Mesh-Under Routing (C-MUR) for Improving IPv6 Packet Arrival Rate over Wireless Sensor Networks

The 6LoWPAN protocol is used in delivering IPv6 packet over IEEE 802.15.4 based wireless sensor networks (WSNs). In 6LoWPAN, adaptation layer is introduced in the protocol stack so that routing can be performed either in the adaptation layer, called mesh-under routing (MUR), or in the network layer, called route-over routing (ROR). To deliver an IPv6 packet over a WSN, the packet has to be divided into multiple fragments, with each being carried in an IEEE 802.15.4 frame, due to the small payload of an 802.15.4 frame. Thus, MUR exhibits the drawback of low packet arrival rate (PAR) when delivering an IPv6 packet over a route consisting of multiple unreliable links in the WSN because the destination node cannot assemble the original IPv6 packet if any fragment of the packet is lost over any link. This drawback is remedied by the proposed chained MUR (C-MUR) scheme, in which some intermediate nodes between the source and the destination are chosen as temporary assembling nodes (TANs), where the received fragments are assembled into the original IP packet and the assembled packet is fragmented again and delivered to the next TAN or the destination node. Experiments show that C-MUR outperforms both MUR and ROR in terms of PAR.