  Several channels with asynchronous side information are introduced. We first
consider single-user state-dependent channels with asynchronous side
information at the transmitter. It is assumed that the state information
sequence is a possibly delayed version of the state sequence, and that the
encoder and the decoder are aware of the fact that the state information might
be delayed. It is additionally assumed that an upper bound on the delay is
known to both encoder and decoder, but other than that, they are ignorant of
the actual delay. We consider both the causal and the noncausal cases and
present achievable rates for these channels, and the corresponding coding
schemes. We find the capacity of the asynchronous Gel'fand-Pinsker channel with
feedback. Finally, we consider a memoryless state dependent channel with
asynchronous side information at both the transmitter and receiver, and
establish a single-letter expression for its capacity.
