Grid based routing in cognitive radio networks for concurrent communication

摘要

Cognitive Radio Network (CRN) exploits the spectrum hole in licensed bands by allowing co located cognitive users to communicate among themselves when licensed users are idle. In such opportunistic communication, the cognitive users need to vacate the channel as and when the licensed user becomes active. Most of the time such sudden termination of ongoing sessions of cognitive devices leads to unacceptable overhead and degrades service quality. So, in this paper a new routing protocol is proposed which emphasizes on concurrent communication of cognitive users rather than opportunistic communication. In concurrent communication cognitive devices are allowed to communicate even in the presence of licensed users activity by controlling the transmission power of cognitive devices such that they do not interfere with the ongoing conversation of licensed users. The algorithm is based on the full location information with the assumption that each of the cognitive device can detect the location information of its own and any other cognitive device in the network. All cognitive devices are arranged into grid cells and every grid selects a grid Head (gH) based on some predefined criteria who takes care of routing. Further, the protocol also suggests a routing zone and forwarding region based on the location of the destination in order to reduce routing overhead and faster route establishment. The simulated results of the protocol is compared with CAODV protocol and observed an improvement in packet delivery ratio and routing overhead.