A new MAC protocol is proposed for the reachback operation in a
wireless sensor network deployed for reconstructing a random field.
Referred to as QUality-of-service specific Information REtrieval
(QUIRE), the proposed protocol optimizes the network performance
under the metric of information rate per slot per Joule while ensuring
a given QoS requirement. Based on the density of deployment and the
QoS requirement specified by the maximum distortion for reconstructing
the random field, QUIRE partitions the sensor network into disjoint
and equal-sized cells. It completely eliminates redundant transmissions
by ensuring, via carrier sensing, that only one sensor in each cell
transmits.
It fully explores the diversity of a fading environment by incorporating
the channel state information into carrier sensing so that the sensor
with
the best channel transmits. Simulation results demonstrate that
QUIRE
achieves orders of magnitude of improvement in system latency and energy
expenditure over fixed allocation schemes such as TDMA and random
access protocols such as slotted ALOHA.