Adaptive Packet Level Redundancy Mechanisms for Reliable Mobile Multicast: Proposed Architecture and Performance Analysis

In this paper, we investigate how packet level redundancy mechanisms could be combined with ARQ (Automatic Repeat reQuest) to achieve scalable reliable mobile multicast transmissions. We consider three redundancy mechanisms. The first one called FEC-based mechanism is that redundant packets are achieved by FEC (Forward Error Correction) encoding. The second type called Replicate-based mechanism is that redundant packets are achieved by replication. Combination of FECbased and replicate-based is used in the last mechanism called FEC-Replicate-based mechanism. We also propose a novel adaptive packet level redundancy mechanism based on FEC-Replicate-based mechanism. To design a novel packet level redundancy mechanism, we start with analyzing comparative performance of four reliable multicast mechanisms, which are Pure NAK-based mechanism, NAK-FEC-based mechanism, NAK-Replicatebased mechanism, and NAK-FEC-Replicate-based mechanism. In addition, simulation is provided to evaluate the four mechanisms when both data packets and feed back packets might be lost. The simulation and analysis show that FEC-Replicate-based mechanism could be the best for using in reliable mobile multicast applications, which have different packet priorities.