Performance analysis of implicit acknowledgement coordination scheme for opportunistic routing in wireless sensor networks

The Opportunistic Routing (OR) protocol provides an alternative and efficient method for exploiting the spatial and temporal characteristics of wireless networks. In addition to prioritisation and selection of relay nodes, another important aspects of the OR protocol is its ability to coordinate between potential relays node. A common approach for coordination is based on a mechanism known as the slotted time and priority-based acknowledgement scheme which relies on the use of control packets. In resource-constrained wireless sensor networks (WSN) with limited amount of energy, an excessive number of transmissions involved in the scheme may not be favourable. In addition, the coordination time overhead for this scheme can also potentially increase the end-to-end delay which can be critical for the WSN applications with delay-constraint requirement. In this paper, we propose a coordination scheme that achieves better energy efficiency with shorter end-to-end delay for WSNs. Through simulation analysis, we show the advantage of the proposed scheme in terms of the average packet's end-to-end delay and energy efficiency.