MAC与TCP跨层的认知无线网络传输性能增强

认知无线网络中,认知用户需要具备频谱感知的功能,在主用户到来时,可以实现动态频谱切换,从而不影响主用户的通信.但是频谱感知和切换带来的时延可能使认知用户TCP频繁的启动慢启动,而影响传输性能.提出的TCP-CWN(TCP for cognitive wireless network认知无线网络TCP)算法,通过TCP-MAC跨层可以消除由于频谱感知和切换带来的慢启动问题.本方案在NS2上进行仿真,实验结果显示在认知环境下TCP-CWN能很好的缓解由于频谱感知对传输的影响,提高认知用户的传输吞吐量.

TCP Enhancement For Cognitive Wireless Network Based on MAC and TCP Cross-Layer

In order to have a little affect on primary users＇ transition, the second users have to be switched to another channel by the time the primary users come, therefore, the function of sensing should be attached to cognitive code in cognitive wireless network. The slow-start in TCP of cognitive code, however, is caused by the sensing and switching delay, which slow down transit-rate sharply. In this paper, TCP-CWN was proposed to get rid of the frequently slow-start. The algorithm was simulated in NS2, the experimental result illustrated that the TCP-CWN has better performance improvemerrt than TCP when comes to transition in terms of reducing the influence of spectrum handoff in cognitive wireless network.