The following article (copy enclosed) reports on the application of pervasive
computing to healthcare.
Varshney, U. (2007) Pervasive Healthcare and Wireless Health Monitoring. Mobile
Network and Applications. 12(2-3). p. 113-127.
Critically review this article and answer the questions A1 to A3.
A1: Give a summary of the contributions of this article (not more than 500 words).
A2: Evaluate the technologies used in the application presented in this paper and argue
whether there are better technologies available today that can improve the quality of
A3: Discuss the properties of this application with respect to the five key properties of
pervasive systems. (10%)
Section B: Design your own pervasive system (40%)
Learning outcomes assessed: LO1, LO2 & LO4
B1: Propose your own pervasive computing system for a specific application. Give a
detailed description of the functionalities of your system. (10%)
B2: Give a detailed critical review of existing related systems and demonstrate the
novelty of your proposed system (900 words). (10%)
B3: Identify and justify the technologies needed for the implementation of the
proposed pervasive computing system . (5%)
B4: Design the architecture of your proposed pervasive system and explain the role of
each component. (10%)
B5: Discuss the properties of your proposed system with respect to the five key
properties of pervasive systems. (5%)
Section C: Modelling and Analysis (35%)
Learning outcomes assessed: LO1 & LO3
A Simple Infostation-based Communication System
An infostation system is an infrastructural system concept that provides many-time,
many-where wireless data services. This case study is a simple context-aware
infostation-based system which allows users to exchanges text messages using mobile
devices such as laptops, smart phones or tablet computers. Typically, an infostation
system comprises one central infostation centre (ISC) and many wireless access
points, called infostations (ISs), deployed at key positions to maximise coverage. The
ISs are physically connected to the ISC via network cables.
In this example we consider a university that has 3 campuses A, B and C. Each
campus has its own infostation system (with one ISC and many ISs). The ISCs of the 3
campuses are physically connected by cables to a network hub to enable users located
at different campuses to exchange messages, as depicted in Figure 1.
An infostation is aware of any mobile device within its range and is able to interact
with the device, e.g. by exchanging messages. A user within the range of an
infostation can send or receive text messages using a mobile device. For the sake of
simplicity, we assume that a text message contains the following information:
Once an infostation receives a text message, it checks if the recipient is within range in
which case it forwards the message to the recipient. If the recipient is not within the
range of that infostation, the infostation forwards the message to the infostation centre
it is connected to.
An infostation centre is aware of all the infostations connected to it and subsequently
of all the devices within the ranges of these infostations. However, an infostation
Figure 1: An infostation-based communication system
centre has direct communications only with the infostations and the network hub
connected to it. When an infostation centre receives a text message from an
infostation, it looks for the infostation where the recipient is located and forwards the
message to this infostation. The infostation where the recipient is located then
forwards the request to the recipient mobile device. If the recipient is not found in one
campus, the message is forwarded via the network hub to the infostation centres of the
other campuses for delivery.
When the network hub receives a message from one ISC, it sends the message to the
What to Do
You are required to model the Simple Infostation-based Communication System in the
Calculus of Context-aware Ambients (CCA) and to analyse this model using the CCA
simulator ccaPL. We assume there are four ISs and one ISC in each campus, named as
in Figure 1 (IS1a, IS1b, …) and two user mobile devices (Bob’s and Alice’s). Each of
these entities and the network hub can be modelled as an ambient in CCA. We say that
a user’s mobile device is in the range of an infostation IS if the ambient modelling that
mobile device is a child ambient of the ambient representing the infostation IS.
Answer the questions C1 to C7.
C1: Give the CCA specification of the ambient modelling the infostation IS1a. (5%)
C2: Give the CCA specification of the ambient modelling the infostation centre ISC1.
C3: Give the CCA specification of the ambient modelling the network hub. (5%)
C4: Deduce from C1-C3 the specification of the whole system (without Bob’s and
Alice’s mobile devices). (8%)
Assume Bob is willing to send the message hello to Alice. For this communication to
take place, their respective mobile devices can be modelled in CCA as follows:
Give the simulation results of the system for the following scenarios. These results
must include the listings of the execution output and the interpretation (explanation) of
the execution output.
C5: Scenario 1: Bob and Alice are both in range with the same infostation, IS1b say.
C6: Scenario 2: Bob and Alice are both in Campus B, say; Bob in range with the
infostation IS2a and Alice in range with the infostation IS2d. (4%)
C7: Scenario 3: Bob is in range with the infostation IS1a in Campus A while Alice is
in range with the infostation IS3a in Campus C. (4%)