Information Technology Reference
In-Depth Information
extends towards the source, each intermediate node
invalidates routes to any unreachable destinations.
When the source of the data receives the RERR,
it invalidates the route or routes in question and
performs route discovery if necessary.
significantly reducing congestion. The potential
impact within health care remote system applica-
tions could be important for the following two
reasons. First, with the increase in POC (Point
Of Care) technologies, future healthcare devices
will require more bandwidth for communication
purposes. Secondly, during large scale disasters
and/or medical emergencies, it is quite likely
that the sensors placed in the different patients
will sense and transmit vital patient information
very frequently and simultaneously, leading to
the increased likelihood of congestion (examples
include natural calamities such as earthquakes
or epidemic diseases). In all the aforementioned
scenarios, congestion can lead to the dropping of
packets, increased consumption and a reduction of
the throughput. Next, the present work impacts on
the management and reliability of the healthcare
system. Moreover, it improves the management
of vital signs in life-critical applications in which
the packets carrying information from a dying pa-
tient need to reach their destinations on time. Our
proposed QBAR (Queue Based Ad hoc Routing)
protocol is built on the top of AODV and performs
a routing strategy based on the hop-by-hop queue
level in order to mitigate dynamic congestion.
From the technological point of view, the algo-
rithm is implemented in the transport layer of the
traditional network stack model and is designed
to work with any MAC protocol in the data-link
layer with only minor modifications.
In the simulation validation, we have con-
sidered the IEEE 802.15.4 standard protocol
and ZigBee technology (this will be referred to
hereinafter as ZigBee). ZigBee meets the needs
of sensors and control devices: they do not need
a high bandwidth but do need a low latency and
very low energy consumption for long battery
lives and for large device arrays. So, ZigBee is a
promising standard that specifically addresses the
needs of wireless control and monitoring applica-
tions. ZigBee uses the TDMA standard modulation
with time slots of 10 ms (ZigBee, 2004).
MAIN FOCUS OF THE CHAPTER
The wide diffusion of healthcare monitoring sys-
tems allows continuous remote patient monitoring
and diagnosis by doctors. The problem of conges-
tion is due to the uncontrolled increase of traffic
with respect to the network capacity and it affects
the reliability of transmission of information and
the loss of packets in any network. In addition,
in wireless sensor networks congestion increases
the dissipated energy at the sensor node. In many
health care applications (e.g. electrocardiogram
monitoring and tele-cardiology), communication
links carry vital information between the patient
and the monitoring devices that needs to be
transmitted in short ”bursts” requiring a reliable
connection. It is a fundamental issue for health
care systems to design an appropriate protocol
solution addressing reliability, energy efficiency,
scalability, reduced packet losses and a timely
delivery without failure.
Although applications of congestion control
based on the AODV protocol modification have
been investigated for many types of communica-
tion networks, they cannot deal with a dynamic
environment as pointed out in the above paragraph.
Moreover, the benefits of adopting a cooperative
strategy in health care systems have not been suf-
ficiently exploited. To achieve this aim, we first
present a cooperative control strategy at each node
to reduce the congestion in specific acute care,
clinical disease and outbreak/disaster situations.
Finally, we highlight how the cooperative strategy
could be promising for future health care system
management. We use a realistic simulation envi-
ronment to show the feasibility of our approach in
Search WWH ::
Custom Search