A Synchronous Channel Hopping Sequence for Self Organized Cognitive Radio Networks
Widist Bekulu Tessema, Murad Khan, Byeongung Kim and Kijun Han
Cognitive Radio (CR) technology solves the problems of the inefficiency in the limited spectrum usage by self-organized wireless network in an opportunistic manner. In cognitive radio networks, a pair of CR users wishing to communicate should ﬁrst agree on a specific channel called control channel. In this paper, a particular emphasis is given to distributed coordination between CR users to establish a control channel between CR users. Channel Hopping (CH) protocol is a sequence-based approach that provides an effective method for implementing rendezvous without relying on a Common Control Channel (CCC). In this approach, all CR users hop to the same rendezvous channel; hence, this channel will serve as a control channel between them. In this paper, we propose a Synchronous Channel Hopping Sequences (S-CHS) to establish a link in CR networks with the assumption of global clock synchronization. Our scheme provides successful communication rendezvous within a bounded time interval. The proposed scheme is compared with existing schemes in context of Time To Rendezvous (TTR), effect of Primary User (PU) appearance, average channel load, channel utilization ratio, and degree of overlap. The simulation results showed that the proposed scheme outperforms existing scheme (Synchronous Efficient Channel Hopping (SYNC-ETCH)) in context of average TTR, maximum TTR and channel utilization ratio. Similarly, the proposed scheme shows better performance than the Maximum Quorum-Based Channel Hopping (M-QCH) technique in context of channel utilization ratio and degree of overlap.
Keywords: Cognitive radio; self organizing; synchronous rendezvous; channel hopping sequences.