  In distributed communication, each transmitter prepares an ensemble of
channel codes. To encode a message, a transmitter chooses a channel code
individually without sharing the coding choice with other transmitters or with
the receiver. Upon receiving the block of channel output symbols, the receiver
either decodes the messages of interest if a pre-determined reliability
requirement can be met, or reports collision otherwise. Revised from the
distributed channel coding theorems in the literature, distributed capacity of
a discrete-time memoryless multiple access channel is defined and derived under
the assumption that codeword length can be taken to infinity. An improved
achievable error performance bound is presented for the case when codeword
length is finite.
