  Recent work for single-relay channels shows that quantize-forward (QF) with
long-message encoding achieves the same reliable rates as compress-forward (CF)
with short-message encoding. It is shown that short-message QF with backward or
pipelined (sliding-window) decoding also achieves the same rates. Similarly,
for many relays and sources, short-message QF with backward decoding achieves
the same rates as long-message QF. Several practical advantages of
short-message encoding are pointed out, e.g., reduced delay and simpler
modulation. Furthermore, short-message encoding lets relays use decode-forward
(DF) if their channel quality is good, thereby enabling multiinput,
multi-output (MIMO) gains that are not possible with long-message encoding.
Finally, one may combine the advantages of long- and short-message encoding by
hashing a long message to short messages.
