Impact of bit errors on the performance of DCF for wireless LAN

The IEEE 802.11 standard for wireless LAN employs a CSMA/CA (carrier sense multiple access with collision avoidance) MAC protocol with binary exponential backoff, called distributed coordination function (DCF). DCF describes two techniques for packet transmission, the default two-way handshaking technique called basic access mechanism and an optional four-way handshaking technique known as request-to-send/clear-to-send (RTS/CTS) mechanism. We present an analytical model to evaluate the performance of the DCF in the case of bit errors appearing on the transmitting channel. The impacts of bit errors on the performances of both basic and RTS/CTS access mechanisms are analyzed and compared. It is shown that the performance of the basic access scheme is significantly affected by bit errors in the wireless channels.