Proportional Fair Coding for 802.11 WLANs

We consider an 802.11 WLAN with lossy links and flow delay deadlines and we derive the joint allocation of coding rate and airtime that achieves the proportionally fair throughput allocation. The noisy wireless links are modelled as bit-level binary symmetric channels (BSCs). We show that the joint optimisation decomposes into decoupled allocation tasks, i.e. partitioning into layers is optimal, and the optimal allocation assigns equal total air-times to flows.