Improving Common Control Channel Capacity and Performance for Cognitive Radio Networks

Abstract

Cognitive radio (CR) is a promising solution to cope with the inefficient usage of the frequency spectrum. CR lets its users leverage empty or idle parts of spectrum opportunistically. The medium access control (MAC) sub-layer in CR based networks is playing a crucial role in controlling user’s access to the shared medium and their interaction with Primary Users as well. Coordination and controlling users’ access to common control channel (CCC) at MAC sublayer can be a challenging issue in this type of networks. High availability of this channel is very important and crucial, so designing a mechanism which contributes to this, is of great importance. The CCC’s limited capacity alongside a large number of contending nodes for it causes channel saturation and consequently, leads to its unavailability. The paper introduces a useful method to compute supported saturation capacity of the CCC. It also introduces a new access mode for CCC called “Channelization”, to improve saturation capacity for it. The effect of “Channelization” scheme is also investigated on average packet delay, and according to it desirable parameters for channelization is calculated. Analytical analysis alongside simulation result shows that the channelization method can have a great impact on the increasing saturation capacity, and lower average packet transmission delay.