A TCP Enhancement Technique Based on MAC and TCP Cross-Layer Cooperation in Cognitive Radio Networks
Li Zhao, Changping Huang, Chen Tiejun - · International Conference on Electronics, Communications and Control · 2012
For the problem of frequent slow-start in cognitive radio networks (CRN) due to spectrum sensing and handoff, an enhancement technique of Transmission Control Protocol (TCP) will be studied in this paper. The cognitive users are different from ordinary users, which do not have spectrum sensing and handoff delay. The cognitive users have to cope with the extra delay otherwise, one or more packets probably would be retransmitted during the spectrum sensing and handoff process. Due to the periodically spectrum sensing, the slow-start in the TCP of cognitive users appear frequently, which slow down sending-rate sharply. Given the problem, a cross-layer cooperation scheme, called as TMCC (TCP and MAC Cross-layer Cooperation), is proposed to get rid of the frequent slow-start in this paper. It is simulated to verify its feasibility by using NS2, and its results show that the retransmission ratio and RTT jitter can be improved substantially compared with the standard TCP.