Busy Tone based Prioritized Access for distributed wireless networks

Although the physical transmission rate increases rapidly, the quality of service (QoS) support for real-time traffic remains a challenge. 802.11 EDCA can only provide service differentiation, but not ensure the QoS as expected because of the restrained real-time traffic capacity and the uncertainty of prioritized access. This paper proposes a distributed MAC protocol called the Prioritized Access based on Busy Tone (PABT), which utilizes the in-band busy tone reservation, preemptive scheduling and adaptive CW tuning simultaneously to resolve the problems. Simulation results demonstrate that the proposed protocol provides a remarkable improvement in terms of the real-time traffic capacity, throughput and packet loss rate.