PERVASIVE SYSTEM

Paper, Order, or Assignment Requirements

Section A: Critical review (25%)

Learning outcomes assessed: LO1 & LO4

Assessment indicators:

  • Clarity
  • Conciseness

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).

(7%)

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

this application.(8%)

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

Assessment indicators:

  • Originality
  • Creativity
  • Clarity
  • References

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

Assessment indicators:

  • Clarity
  • Conciseness
  • Correctness

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:

  • the sender’s username
  • the recipient’s username
  • the message content.

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

other ISCs.

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.

Modelling

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.

(5%)

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%)