On the throughput of multicasting with incremental forward error correction

In this paper, we consider a multicasting model that uses incremental forward error correction (FEC). In this model, there is one sender and rⁿ receivers. The sender uses an ideal (n,n(1-p),np) FEC code to code a group of n(1-p) data packets with additional np redundant packets so that any set of n(1-p) packets received by a receiver can be used to recover the original n(1-p) data packets. Packets to the receivers are lost independently with probability q. For this model, we prove several strong laws of large numbers for the asymptotic throughput as n → ∞. The asymptotic throughput is characterized by the unique solution of an equation in terms of p, q, and r. These strong laws not only provide theoretical justification for several important observations made in the literature, but also provide insights that might have impact on future design of multicasting protocols.