A channel condition dependent QoS enabling scheme for IEEE802.11 Wireless LAN and its Linux based implementation

This paper presents a distributed adaptive bandwidth allocation scheme, designed to provide quality of service support in IEEE 802.11 wireless LANs. A centralized bandwidth manager that runs at the access point performs the dynamic bandwidth allocation based on the realtime wireless channel condition and the service policy of downlink and uplink traffic. A set of distributed bandwidth agents, which are located on the mobile hosts, perform uplink traffic scheduling according to the quality of service requirement of different applications that are running at the devices. At the same time, real-time wireless channel monitors provide information regarding the condition of the wireless channel to the centralized bandwidth manager. In this paper, we discuss the design of the distributed adaptive bandwidth allocation scheme and the interactive signaling mechanism between the centralized manager and the distributed agents. Furthermore, we set up and provide results from our experimental IEEE 802.11b wireless LAN test environment, where we have implemented the designed technology. A thorough test and performance analysis are also presented in this paper.