Abstract:
In medical body area network small sized medical sensors are attached to a
patient's body for continuous and real-time monitoring of biomedical vital
signs. These nodes collect data from patient's body and send it to base sta-
tion via intermediate node so that doctors/caregivers can access the patient's
data or can be timely informed if any patient's condition goes critical. But
due to the small size, these sensor nodes have low data rates, small transmis-
sion ranges, limited battery power and processing capabilities etc. On the
other hand reliability is most important issue in medical body area network
because of critical nature of patient's data. Any wrong or missing or delayed
data can create a situation in which doctors or caregivers may take wrong
decisions about patient's health which can have fatal results. Reliability of
data transmission can be ensured on the cost of power consumption in net-
work by using di erent methods such as retransmissions, acknowledgments
and guaranteed time slot mechanism etc. We propose an e cient MAC to
achieve both reliability and energy e ciency in medical body area network
at acceptable trade-o levels. The Proposed MAC not only overcomes the
limitations of existing ZigBee MAC such as ine cient CSMA/CA mechanism
and underutilization of guaranteed time slots but also it adapts di erent traf-
c types such as emergency tra c and normal tra c. The proposed MAC
is implemented in Castalia simulator and simulations results show that the
application level throughput and packet delivery ratio of network increase
and packet loss rate decreases at MAC level. We also optimize the energy
utilization of network by reducing the number of retransmissions and also
by tuning the parameters of ZigBee MAC i.e. macMaxCSMABacko s and
macMinBE.
