A statistical receiver-based approach for improved throughput of multimedia communications over wireless LANs
Delay-sensitivity of real-time applications stipulates resilience against errors and losses in multimedia content. Such resilience is particularly important for bandwidth-constrained and error-prone wireless networks. Recent wireless studies have highlighted that significant improvements in bandwidth utilization and multimedia quality can be achieved if the decision to retain or drop "corrupted" packets is made at the application layer instead of medium access, network or transport layers. Such a strategy, however, necessitates that the maximum number of (good and bad) packets are relayed to the application layer while minimizing any modifications (if any) to the widely-deployed UDP/IP protocol stack. Previous studies have proposed that, while ignoring corruptions in packet payload, only packets with errors in the headers should be dropped. We introduce a receiver-based scheme which uses the history of a multimedia session to correct packet header errors, thereby improving the throughput of real-time applications over wireless local area networks (LANs). The proposed scheme is truly receiver-based and, therefore, does not require any modifications to the source or any intermediate network node. Only minor modifications are required to the protocol stack of the multimedia receiver. Specifically, the proposed scheme generates statistics based on the history of "critical" protocol header fields for active multimedia sessions. These statistics are in turn employed to (a) correct errors in the critical fields and (b) determine if the relevant packets belong to the receiver's session of interest.