Priority-based separate backoff scheme for service differentiation in IEEE 802.11 WLAN

The IEEE 802.11 standard specifies a distributed coordination function (DCF) service for best-effort data transfer like FTP or telnet, and a point coordination function (PCF) service for delay-sensitive data transfer like audio and video. DCF is not suitable for real-time applications whereas PCF is complex and expensive to implement. So it is important to enhance DCF to support differentiated services among various applications. We propose a new and simple priority-based backoff scheme to provide service differentiation while maintaining overall system performance. We model our proposed scheme using a Markov chain and analyze its performance.