  In this paper, we consider the problem of exchanging channel state
information in a wireless network such that a subset of the clients can obtain
the complete channel state information of all the links in the network. We
first derive the minimum number of required transmissions for such partial
third-party information exchange problem. We then design an optimal
transmission scheme by determining the number of packets that each client
should send, and designing a deterministic encoding strategy such that the
subset of clients can acquire complete channel state information of the network
with minimal number of transmissions. Numerical results show that network
coding can efficiently reduce the number of transmissions, even with only
pairwise encoding.
