Summary: | In recent years there has been a growing trend in optical wireless convergence.
One particular aspect of this is 60 GHz radio-over-fiber technology. It is intended for use
in wireless personal area networks. However, we think that the same technology could be
used for monitoring applications in the indoor environment. It could be used to detect
emergency situations or to detect intruders. We shall examine reasons why this choice
might be a suitable one. We shall then propose a MAC layer protocol to accomplish this
task. Since in case of emergency we might require to obtain data from only one node for
an extended duration, flexibility in implementation is required. We shall develop an
adaptive MAC protocol where this would be possible. We accomplish this by including
two protocol modes called the Icarus mode, which is to be used in case of an emergency
and the Resync mode which is used when normality is restored. A significant problem at
high frequencies is that the beam becomes increasingly narrow and behaves more in a ray
like condition. This implies that particularly in an indoor environment it is possible that
the beam may be accidentally blocked. In this case the node must be able shift the beam
in order to enable communication. We demonstrate three such strategies and offer a
comparative analysis.
|