An Achievable Region for the Double Unicast Problem Based on a Minimum Cut Analysis

作者:Huang Shurui*; Ramamoorthy Aditya
来源:IEEE Transactions on Communications, 2013, 61(7): 2890-2899.
DOI:10.1109/TCOMM.2013.053013.120542

摘要

We consider the multiple unicast problem under network coding over directed acyclic networks when there are two source-terminal pairs, s(1) - t(1) and s(2) - t(2). The capacity region for this problem is not known; furthermore, the outer bounds on the region have a large number of inequalities which makes them hard to explicitly evaluate. In this work we consider a related problem. We assume that we only know certain minimum cut values for the network, e.g., mincut (S-i, T-j),where S-i subset of {s(1), s(2)} and T-j subset of {t(1), t(2)} for different subsets S-i and T-j. Based on these values, we propose an achievable rate region for this problem using linear network codes. Towards this end, we begin by defining a multicast region where both sources are multicast to both the terminals. Following this we enlarge the region by appropriately encoding the information at the source nodes, such that terminal t(i) is only guaranteed to decode information from the intended source s(i), while decoding a linear function of the other source. The rate region depends upon the relationship of the different cut values in the network.

  • 出版日期2013-7