We present capacity results of the binary-symmetric parallel-relay network,
where there is one source, one destination, and K relays in parallel. We show
that forwarding relays, where the relays merely transmit their received
signals, achieve the capacity in two ways: with coded transmission at the
source and a finite number of relays, or uncoded transmission at the source and
a sufficiently large number of relays. On the other hand, decoding relays,
where the relays decode the source message, re-encode, and forward it to the
destination, achieve the capacity when the number of relays is small.Comment: accepted and to be presented at ISIT 201