Spatiotemporal Multicast in Sensor Networks

Qingfeng Huang
Chenyang Lu
Gruia-Catalin Roman

Sensor networks often involve the monitoring of mobile phenomena, which can
be facilitated by a spatiotemporal multicast protocol we call "mobicast".
Mobicast is a novel spatiotemporal multicast protocol featuring a delivery
zone that evolves over time.  Mobicast can in theory provide absolute
spatiotemporal delivery guarnatees by limiting communication to a mobile
forwarding zone whose size is determined by the global worst-case value
associated with a compactness metric defined over the geometry of the
network.  In this work, we first studied the compactness properties of
sensor networks with uniform distribution.  The results of this study
motivate three approaches for improving the efficiency of spatiotemproal
multicast in such networks.  First, one may achieve high savings on
communication overhead by slightly relaxing spatiotemporal delivery
guarantees.  Second, spatiotemporal multicast may exploit local compactness
values for higher efficiency for networks with non uniform spatial
distribution of compactness.  Third, for random uniformly distributed sensor
network deployment, one may choose a deployment density to best support
spatiotemporal communication.  We also explored all these directions via
mobicast simulation and results are presented in this paper.