Security Issues in Monitoring Medical Disease Through Vehicular Ad hoc Network - Proceedings of All India Seminar on Biomedical Engineering 2012 (AISOBE-2012) - page 141

Introduction
Ad hoc networks are a new paradigm of wireless communication for mobile hosts
(which we call nodes). In an ad hoc network [ 1 ], there is no fixed infrastructure
such as base stations or mobile switching centers. Mobile nodes that are within
each other's radio range communicate directly via wireless links, while those that
are far apart rely on other nodes to relay messages as routers (Fig. 1 ).
The embedded architecture can be seen in a variety of applications such as
invasive sensing, urban sensing, automotive, air and space, and the health care
industry. Different platforms have been introduced which can be used to monitor
medical data while the patient is out of hospital. These architectures can be used
for two classes of applications, some are life critical (ECG Monitoring) and some
are not (monitoring the pressure on the feet or the way people are walking after
post-knee surgery). Some of the applications that are life critical must have the
capability of reporting medical data to physicians with fixed schedules periodi-
cally. In addition, these classes of applications must be able to notify the para-
medics in case of any emergency to get immediate response. In all the cases when
an application intends to transfer data to its appropriate destination, the patient
must either be under coverage of a Wi-Fi wireless access point or its on-body
terminal must have the capability of using the cellular network. However, in some
cases (emergencies, attacks, etc.), neither the Wi-Fi nor the cellular network is
available. This fact introduces a major reliability issue regarding the extension of
these applications to mobile patients. Vehicles collect data from patients and
transfer them to their final destination using ad hoc networks, where each mobile
node is a vehicle. The vehicles communicate with each other and with nearby
local roadside base stations. Vehicles move in an organized fashion and their
range of motion is somehow restricted. For example, they mostly drive in the
streets and highways. Moreover, a commuter drives everyday at almost about the
same time to work and returns home almost following the same path. Security is
an important issue for ad hoc networks, especially for those security-sensitive
applications.
Mobile nodes that are within each other's radio range communicate directly via
wireless links, while those that are far apart rely on other nodes to relay messages
as routers. Node mobility in an ad hoc network causes frequent changes of the
network topology. Figure 2 shows such an example: initially, nodes 1 and 4 have
a direct link between them. When 4 moves out of 1's radio range, the link is
broken. However, the network is still connected, because 1 can reach 4 through 3,
5, and 6.
Ad hoc networks can also be used for emergency, law enforcement, and rescue
missions. Since an ad hoc network can be deployed rapidly at relatively low cost, it
becomes an attractive option for commercial uses such as sensor networks or
virtual classrooms [ 2 , 3 ].