Abstract
In 6LoWPAN, IPv6 packet's fragments are forwarded using multi-hops route-over routing protocols. Although conventional route-over achieves high packet delivery ratio, it has high delay due to the hop-by-hop fragmentation and reassembly. Conversely, enhanced route-over reduces the delay through avoiding the hop-by-hop fragmentation and reassembly. However, it hurts back the packet delivery ratio especially when the number of packet's fragments is high. This paper presents route-over with end-to-end fragmentation and reassembly using adaptive backoff exponent (ROE2E-ABE). In this protocol, MAC and adaptation cross-layer integration is exploited to adapt the backoff process based on number of fragments. Initially, the relationship between the backoff exponent and the number of fragments is derived. The number of fragments is calculated and embedded within the adaptation layer header. When the MAC layer receives the fragment from upper adaptation layer, it retrieves the number of fragments from the header, calculates the backoff parameters and performs the backoff process accordingly. The simulation shows that ROE2E-ABE outperforms both conventional and enhanced route-over routing protocols in terms of packet delivery ratio, average end-to-end delay, average throughput and average energy consumption. The simulation results are validated using testbed implementation. The ABE in ROE2E-ABE manages interferences and improves the route-over routing performance.