A method of communicating information from first and second transponders (or
multiple
transponders) to a central monitoring device, and a communications apparatus, are
disclosed. The method includes receiving a starting indication at the transponders,
determining start times for the transponders in response to that indication, and
transmitting first and second sets of bursts from the first and second transponders,
respectively. The bursts of the first set occur at at least some of a first set
of potential transmission times within an interrogation period, and the bursts
of the second set occur at at least some of a second set of potential transmission
times during that period. Each of the potential transmission times of the burst
sets are respectively determined in relation to the start times of the respective
transponders. The potential transmission times of the respective burst sets are
separated from one another by one of a bit-cell period and a multiple thereof.