OARE: Overhearing-Aided Redundancy Elimination in Multirate WLANs

In general, an access point (AP) in wireless local area networks (WLANs) can be easily congested since all related data traffic goes through it. To satisfy the quality-of-service (QoS) requirement for its customers, a protocol-independent redundancy elimination (RE) technique can effectively mitigate the congestion at the AP by reducing redundant data traffic. In this paper, we propose an overhearing-aided RE (OARE) scheme for multirate WLANs by leveraging the broadcast nature of a wireless medium. In OARE, the AP estimates overhearing probabilities of partially sliced chunks from an incoming packet for a destination mobile terminal by considering an adaptive modulation and coding technique. Then, the original packet is encoded by means of RE to minimize its transfer time to the destination, depending on the estimated overhearing probabilities. Extensive simulation results demonstrate that OARE can reduce the packet transfer time by 7.8%-23.2%, compared with non-RE (or nonencoded) transmissions.