In heterogeneous networks sending messages may incur different delays on different links, and each node may have a different switching time between messages. The well studied Telephone model is obtained when all link delays and switching times are equal to one unit.
We investigate the problem of finding the minimum time required to multicast a message form one source to a subset of the nodes of size k. The problem is NP-hard even in the basic Telephone model. We present a polynomial time algorithm that approximated the minimum multicast time within a factor of O(log k). Our algorithm improves on the best known approximation factor for the Telephone model by a factor of o (log n/log log k). No approximation algorithms where known for the general model considered in this paper.
By: Brauch Schieber, Joseph (Seffi) Naor, Sudipto Guha, Amotz Bar-Noy
Published in: RC21343 in 1998
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