Performance evaluation of QoS control scheme that uses back pressure traffic control

The spread of the Internet has given rise to strong demands for real-time services such as voice and streaming video. Since these services require guarantees that may include transmission rate, delay, and delay variance, the network, including the wireless access networks, must offer QoS (quality of service) guarantees. However, no radio access system fully supports QoS controls. IEEE 802.11e is one scheme that uses an access control mechanism for QoS support. The scheme is based on a distributed access control method, CSMA (carrier sense multiple access). Since it employs EDCA (enhanced distributed channel access) for priority differentiation, terminals with large traffic loads can throttle the throughput of priority terminals because EDCA is essentially decentralized control. This paper proposes a back pressure traffic control method that avoids this problem and supports QoS guarantees as well as describe its characteristics.