On network coding advantage for multiple unicast networks

In this paper, by studying the feasible fractional routing solution under the so-called full reachability condition, we give bounds on the network coding advantage for undirected multiple unicast networks. More precisely, we prove that, for certain class of fully reachable networks, the network coding advantage is upper bounded by 9/8, improving the previous bound 3 by M. Langberg and M. Médard.