A Study On TCP Performance Over Wireless In-band Full-Duplex Networks

In-band Full-duplex(IBFD)is one of the key technologies for wireless communications since it can improve the spectrum efficiency and channel capacity.IBFD enables wireless terminals to transmit and receive at the same time over the same frequency band.The realization of IBFD is based on advanced self-interference cancellation techniques and the influence of IBFD realization on the transport layer is significant.This thesis mainly studies the performance of TCP in IBFD system,based on the analysis of the technical features of IBFD,the channel characteristics of WLAN and the transmission process of TCP.Firstly,different conflict domains are discussed and different TCP performances under different traffic loads are compared between IBFD system and half duplex system.Besides,the influence of self-collision is also studied in different wireless environments.We found that the TCP performance under high traffic loads is better in IBFD systems than in half-duplex systems.Secondly,this thesis compares the change rates of TCP window size in different communication systems in order to analyze the impact of IBFD on window fluctuation.The simulation results show that the growth rate of TCP window size in IBFD wireless is more rapid than that in half-duplex wireless.However,too fast growth of TCP send window size will lead to packet loss,thus more serious window fluctuation.Thirdly,different RTTs in IBFD wireless and half-duplex wireless are compared.The simulation results show that the RTT in IBFD systems is much shorter than that in half-duplex systems.Therefore,the end-to-end latency has been reduced drastically in IBFD systems.