Group-based Any-Path Routing in Cognitive Radio Networks

Abstract

Cognitive radio (CR) technology uses vacant spectrum opportunistically when and where the licensed user of the spectrum is not using it. Specifically, cognitive radio ad hoc networks (CRAHNs) are self-configuring networks of CR devices, which can communicate with each other without infrastructure or fixed spectrum. Routing in CRAHNs must address different spectrum availability among nodes, which is caused by spatial and temporal variation of the licensed user’s activity. Once a routing path has been established, nodes along the route should switch channels to maintain communication because of variable licensed user’s activity. Since channel switching introduces a significant delay, frequent channel switching degrades the performance. In order to reduce the number of channel switching, existing approaches attempt to use spectrum that is expected to remain available for the longest time based on history. However, utilization history is not always available.In this paper, I propose a group-based any-path routing protocol, which is less amenable to the dynamic spectrum usage of the licensed users. The proposed scheme forwards data to any device in the next group instead of a predefined device, which makes use of spatial diversity to reduce channel switching. Simulation results show that the proposed scheme reduces the end-to-end delay and increases route life time when compared to the existing schemes.