However, in order to account for the fact that traf-
fic generated by sensor nodes is highly correlated, a random delay (where the
node keeps its radio o?®) followed by a constant listen period are added before
starting the data transmission. This will lead to e?±cient energy usage and
will alleviate the collision problem. Simulation results show that backo?® with
104 Ali Abu-el Humos et al.
work shows considerable energy savings in single-hop and multi-hop scenarios,
The work in [7] uses the two-radio architecture introduced by PAMAS, but
maintaining efficient energy consumption and bandwidth utilization. It
sender and receiver try to adapt their wakeup times depending on the network
follows the same data transmission sequence as the IEEE 802.11 protocol
latency is not improved in multi-hop scenarios due to the lack of coordinated
Chapter 4 Medium Access Control Protocols for Wireless Sensor Networks
a fixed window size or binary exponential decrease in window size are more
suitable to achieve proportional fairness.
In order to control packet injection into the network, to prevent congestion,
and to maintain acceptable bandwidth utilization level, an adaptive rate
control (ARC) scheme is proposed. Each node determines to increase or decrease
its tra?±c injection into the network independently, without the need
to exchange any tra?±c control packets with other nodes in the network. ARC
is computationally simple and gives preference to route-through tra?±c over
the tra?±c generated from the sensor node application.
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