Creating successful pervasive computing applications is always a possibility, however, special attention needs to be paid on how such applications might adapt and be effective in a particular pervasive computing environment [9]. One can argue with the notion that mobile devices will always be one order of magnitude weaker than their desktop counterparts. As a result, any application expected to run on pervasive computing devices has to account for smaller screen sizes, lower processing power, smaller storage and memory capacity and lower network bandwidth [9].
Clearly, there is a need for alternative thinking how applications can be architected to provide reasonable levels of responsiveness despite the device hardware limitations.
In the previous chapter, we discussed the aspects of pervasive computing environments and how they differed compared to traditional computing environments. What is important to note at this stage is that while pervasive computing devices will almost never achieve the power of their desktop counterparts, they cannot be compared directly because their environment of use, purpose of use, and approach is altogether different. We approach our problem by exploiting these limitations and taking advantage of alternatives to achieve the reasonable results from a pervasive computing perspective.
There have already been several successful commercially deployed pervasive computing applications, such as at National Express [26], The Waterbury Police Department [27], Lotte Sam Kang [28], Kudos Restaurant [29] and Enning GmbH [30]. In the previous chapter, we identified three specific criteria that we identified as necessary for the development of successful pervasive computing applications within a particular computing environment; a successful pervasive computing application is considered as one that:
z Addresses specific application challenges found relevant to the purpose of the application, supports the vision of pervasive computing and enhances the user experience
z Identifies the characteristics of users that will use such an application and take these into account in the development of the application; and
z Considers device limitations by working around them to achieve desired outcomes
In the following sub-sections we attempt to discuss the relevant properties of successful pervasive computing applications and define the scope of the proposed system.
2.4.1 The Pervasive Computing Environment
The pervasive computing environment extends beyond the traditional networked environment to utilize wireless technologies such as IEEE 802.11, CDMA, GPRS, GSM and so forth. Such an environment addresses the goal of providing “anytime, anywhere” information access by decoupling users from devices and viewing applications as entities that perform tasks on behalf of users. There are a number of ongoing projects in this area that focus on holistic pervasive computing environments, including PIMA [2], Carnegie-Mellon University’s Aura project [31], The University of Washington’s Portolano project [32], HP’s CoolTown project [33], MIT’s Project Oxygen [34], The University of California at Berkeley’s Endeavour project [35] and IBM’s Websphere Anyplace project [36].
Most of these projects focus their efforts on creating a platform or environment in which pervasive computing applications might adapt and excel. Other efforts include infrastructure issues, dynamic service discovery, device independent models and so forth.
Due to the extensive and complicated process of setting up a pervasive computing environment, the proposed system will not focus on the network or hardware infrastructure, but rather, as mentioned in the previous chapter, approach the problem from an application-centric perspective and assume such an environment.
2.4.2 Specific Application Challenges
In Section 2.3.5, we identified the application challenges that we found necessary to the development and deployment of successful pervasive computing applications. We focus our efforts on these challenges:
z Automation;
z Content aggregation;
z Customization and personalization;
z Multi-device capability;
z Web content and custom applications; and
z Integration of services.
The proposed system will address each of these application challenges in an attempt to support the vision of pervasive computing from an application-centric perspective. Each of these challenges will be discussed in greater detail in the concluding chapters and will be critically evaluated to identify particular contributions and limitations.
2.4.3 Mobile Users’ Characteristics
Usability is an expansive topic in pervasive computing. While it is a research topic on its own, it does not exist in isolation and needs to be considered when developing and deploying pervasive computing applications. In the previous chapter, we identified the characteristics of mobile users and earlier discussed the usability challenges. In a pervasive computing environment, great importance is placed on the user, how users perform tasks [2] and how results are achieved. We define our target users have the following characteristics:
z They are constantly on the move;
z They have little time and resources at their disposal to perform tasks; and
z They need to perform tasks with the least amount of time, effort and skill.
While there are several usability aspects concerned with the development of such applications, the
proposed system is particularly focused on how the users perform tasks and enhance the user experience rather than on other aspects associated with usability. In the development of the proposed system, we hope to address these characteristics.
2.4.4 Pervasive Computing Device Constraints and Limitations
In addition to considering how users perform tasks, we also need to consider the devices they use and how we can exploit each device constraints and limitations to maximize user efficiency while maintaining a reasonable computing performance. We address the following device limitations:
z Screen size, resolution and color depth
z Processing power and battery power
z Other unique device capabilities