  Due to the large size of wireless networks, it is often impractical for nodes
to track changes in the complete network state. As a result, nodes have to make
distributed decisions about their transmission and reception parameters based
on their local view of the network. In this paper, we characterize the impact
of distributed decisions on the global network performance in terms of
achievable sum-rates. We first formalize the concept of local view by proposing
a protocol abstraction using the concept of local message passing. In the
proposed protocol, nodes forward information about the network state to other
neighboring nodes, thereby allowing network state information to trickle to all
the nodes. The protocol proceeds in rounds, where all transmitters send a
message followed by a message by all receivers. The number of rounds then
provides a natural metric to quantify the extent of local information at each
node.
  We next study three network connectivities, Z-channel, a three-user double
Z-channel and a reduced-parametrization $K$-user stacked Z-channel. In each
case, we characterize achievable sum-rate with partial message passing leading
to three main results. First, in many cases, nodes can make distributed
decisions with only local information about the network and can still achieve
the same sum-capacity as can be attained with global information irrespective
of the actual channel gains. Second, for the case of three-user double
Z-channel, we show that universal optimality is not achievable if the per node
information is below a threshold. Third, using reduced parametrization $K$-user
channel, we show that very few protocol rounds are needed for the case of very
weak or very strong interference.
