Understanding and mitigating TCP starvation in 802.11 wireless mesh networks

It is well known that the pervasive IEEE 802.11 MAC is intrinsically unfair. In particular, in the topology shown in Fig. 1(a), when links AB and CD both carry backlogged transmissions, the packets from sender A experience persistent collisions at node B while sender C enjoys collision-free transmission to D. Node A can transmit successfully only if it is able to "insert" its packets into the small inter-packet gaps of C's packets. Thus, we refer to the topology in Fig. 1(a) as the unfair topology and to C and A as the superior and inferior nodes respectively.

I. Introduction

It is well known that the pervasive IEEE 802.11 MAC is intrinsically unfair [1], [3]. In particular, in the topology shown in Fig.1(a), when links AB and CD both carry backlogged transmissions, the packets from sender A experience persistent collisions at node B while sender C enjoys collision-free transmission to D. Node A can transmit successfully only if it is able to “insert” its packets into the small inter-packet gaps of C's packets. Thus, we refer to the topology in Fig. 1(a) as the unfair topology and to C and A as the superior and inferior nodes respectively.