Minimum Connected Dominating Set based Virtual Backbone Construction in OLSR Protocol

In ad hoc wireless networks, nodes have limited energy and short transmission range. There are no pre-designated routers in these networks and hence routing cannot be done in the conventional way as done in wired networks. To facilitate routing in ad hoc wireless networks, some sort of backbone like structure needs to be built. One of the widely used routing protocols in ad hoc wireless networks is Optimized Link State Routing Protocol (OLSR), which makes use of Multipoint Relay sets (MPRs) to construct the virtual backbone. Various improvements have been proposed in the literature for the MPR selection scheme used in OLSR to improve its efficiency. In this paper, with the aim of enhancing the performance of OLSR, we propose an Improved OLSR (IOLSR) protocol, wherein Minimum Connected Dominating Set (MCDS) is used, instead of multipoint relay sets, to construct the virtual backbone. The performance of IOLSR is compared with that of OLSR in terms of the performance metrics – throughput, packet delivery ratio, end-to-end delay and size of the backbone. From the results, it is found that IOLSR protocol performs better than OLSR with respect to all these metrics.