Biomedical Engineering Reference
In-Depth Information
provides guaranteed delivery mechanism for high priority traffic. This MAC
algorithm is a good MAC design example that has incorporated the physical layer
properties of IR-UWB, such as number of pulses per data bit, and burst trans-
mission period, which can be considered as a unique feature of this design. A
scalable data rate of up to 5 Mbps can be achieved using this MAC protocol
depending on the number of pulses per bit and pulse transmission interval. Also it
is possible to operate the sensor nodes at the maximum allowable transmit power
by selecting the burst transmission slot as mentioned in
Sect. 3.3
. The maximum
total delay demonstrated in the simulations is in the range of 8-12 ms for this
design. The power consumption for a sensor node employing a UWB transmitter
and a narrow band receiver ranges from 2 to 4 nJ/bit. This value is obtained by
considering the power consumption of transmitter and receiver without any
additional interface electronics required for the operation of the sensor node (e.g.
micro-controllers, ADC and front-end amplifiers.
3.6 Conclusion
In this chapter a number of unique techniques have been presented for UWB based
WBAN systems. First of all, a dual band (UWB transmit and narrow band receive)
physical layer is discussed for WBAN sensor nodes to achieve a power con-
sumption lower than the current state of art technologies while maintaining a good
QoS. The technique has been evaluated for a WBAN scheme that is formed by two
networks to enable remote monitoring of a multi-human body environment.
Details of a MAC protocol is discussed and studied for real-time implementation
of WBAN systems. Furthermore, the MAC protocol is designed to dynamically
vary the number of pulses per bit in the UWB transmission according to the
received signal condition. Performance is analyzed by comparing network metrics
presented in the results. From the results it can be observed that using a router as
an intermediate node improves the data transmission within a WBAN. It is also
shown that we can minimize the power consumption and packet delays for a
UWB-based WBAN sensor node using a narrow band receiver. Hardware
implementation of sensor nodes considering the MAC protocol given in this
References
1. K.M. Thotahewa, J.Y. Khan, M.R. Yuce, Power efficient ultra wide band based wireless body
area networks with narrowband feedback path. IEEE Trans. Mobile Commun. (to appear)
2. M.R. Yuce, T.N. Dissanayake, H.C. Keong, in Wideband Technology for Medical Detection
and Monitoring, Recent Advances in Biomedical Engineering, ed. by G.R Naik (InTech,
Florida, 2009). ISBN: 978-953-307-004-9
