An Analysis of Different TCP Variants in Cognitive Radio Networks

Cognitive Radio Networks can use scarce spectrum efficiently and envision as emerging technologies that can fulfill the future demands. In Cognitive Radio Networks, users (or secondary users/ unlicensed users) sense channels and use the idle channels and vacate the channel on being use by primary licensed users so that cognitive users do not interfere with the license users. End-to-end performance of cognitive radio networks plays an important role for applications such as audio-video, infotainment etc. Researches have reported that channel sensing and channel switching overheads lead to large variations in latency and bandwidth parameters. In this paper, we have studied the impact of these variations on transport layer protocols (TCP New Reno, TCP Reno, TCP Tahoe, TCP Sack and TCP Vegas) for Cognitive Radio Ad-Hoc Networks (CRAHN) through simulation on ns-2. On comparing the performance of different TCP variants, we found that TCP New Reno performs better among other TCP variants but remains to adopt environment changes quickly.