Finding an Immuned Path against Single Primary User Activity in Cognitive Radio Networks
Dec 31, 2017
Publisher: Praise Worthy Prize
Due to recent crowdedness in unlicensed spectrum, a new technology is introduced which allows unlicensed users, known as Secondary Users (SUs), to dynamically access licensed spectrum whenever they are not used by their licensed users, known as Primary Users (PUs). Routing in Cognitive Radio Networks (CRNs) is different from traditional routing in wireless networks, since it requires SUs to periodically sense licensed spectrum, channels availability changes over time, knowledge of tolerated interference by PUs. In this paper, a novel routing discovery technique is proposed to find a primary path, if exist, which is immuned to one PU, such that at most one SU fails (must back off transmission) when a PU becomes active again. Also, a backup path can be discovered using the same technique with the condition that it is channel-link disjoint from the primary path. The problem is modeled using a multi-layer graph where each layer corresponds to a channel in a network. The proposed strategy reduces number of required channel-links maintenance to two, if failed due to one PU activity.