Intra-Session Fairness in Multicast Communications

Multicast communication achieves scalability by sending data to multiple receivers at the same time. Receivers in a multicast session usually share the fate with each other, even though their processing speed and the capacity of the path they use can be quite different. A conventional multicast session usually consists of a single multicast group and the problem is how to set the group rate so that it is fair to both fast and slow receivers, to some extent. In a replicated multicast service, receivers are divided into groups based on their capacities and a multicast session can consist of multiple multicast groups. The question is how to divide receivers into groups exactly and set appropriate group rates so that it is fair to all the receivers. Most of current work focuses on optimizing the social welfare represented as a sum of some performance measures of receivers [Kar et al., 2002; Stoenescu et al., 2003]. In this paper, we define a new concept called intra-session fairness and give an optimal solution that can achieve fairness among receivers in the same session.