A framework of radio channel allocation strategy for WLANs with multimedia traffic support

For IEEE 802.11 wireless LANs (WLAN) with multiple access points (AP), it is critical to allocate the limited number of radio channels dynamically and efficiently. This paper proposes a new framework for radio channel allocation (RCA) strategy for WLANs to support multimedia traffic. Two techniques are introduced for this purpose: service differentiation in the MAC layer, and link adaptation in the physical layer. First, we formulate the RCA as a min-max optimization problem regarding channel utilization with constraints of transmitting power and data rates. Second, we derive an expression to evaluate the channel utilization, which incorporates the condition of a wireless channel, such as signal-to-noise (SNR) ratio and transmitting power, in addition to the transmitting probability of a station. It also incorporates the differentiations among the stations within an AP on behalf the traffic flows carried by the links between a station and its AP. Third, we propose a new RCA algorithm that considers both link adaptation and service differentiation mechanisms, which have not been considered by the existing RCA schemes. Simulation results have demonstrated the effectiveness of the proposed strategy.