User Requirements for ‘Future’ Technology

Software Radio: The User Dimension

Kate Cook

QinetiQ Ltd

New technology development is frequently undertaken on a technology-led basis, at least in its early stages. Increasingly, however, and particularly with respect to technologies which promise to impact major existing markets, new approaches are being employed to validate implicit assumptions and thence more effectively direct future technology research. This chapter describes one such approach, which has been applied to understand consumer perspectives and implications of software defined radio technology within the context of the mobile telecommunications market. Bringing together techniques from human factors research and marketing, we describe a methodology of potentially wider relevance, as well as providing scenarios and storyboards for some illustrative end user applications.

5.1 User Requirements for ‘Future’ Technology

Software radio (or software defined radio, SDR) is anticipated to be the next major leap forward in mobile and wireless communications [1] and is seen as an essential compo-nent of future third- (3G) and fourth-generation (4G) mobile communication systems.

This technology will provide an even greater degree of flexibility to the end user and other stakeholders involved in its deployment. For example, it has been suggested that clear benefits can be derived from the application of reconfigurable radio techniques in handset design, particularly in the potential to support multiple air interface standards.

There are a number of proposed advantages for the end user, including enhanced roam-ing capabilities and selection of the most attractive network to meet the user’s prefer-ences [2]. However, hand in hand with this flexibility comes increased complexity and choice. There are likely to be many unique challenges for the designers of the user interaction and user interfaces for future software radio devices. Given that the enabling technologies required for software radio are developing rapidly, it is crucial that detailed user requirements work is carried out while the technology is still being developed.

Users’ requirements need to be understood very early on, not just the immediate

require-ments of end users themselves, but also those of all system stakeholders such as manu-facturers, network operators, and service providers.

5.1.1 Benefits of User-centered Design

The value of a user-centered design process, together with supporting tools and techniques (broadly illustrated in Figure 5.1), is well recognized in the development of computer-based systems. Such a design process analyzes user needs by eliciting requirements directly from users, and considers the impact of emerging designs upon those needs. Prototype systems can be developed and evaluated with real users, in an iterative fashion throughout the design life cycle, providing a means of refining and validating the initial user requirements. To some extent, this approach has been adopted for the development of today’s communication tech-nologies, see, e.g. Refs. [3–6]. Human Factors researchers have developed numerous user-centered design methods and tools to support this process, e.g. Participatory Design [7], Contextual Design [8], and Scenario-based Design [9]. A user-centered approach can thus add significant value to the research and development of products embodying software radio by reducing the risk of developing technology-driven products and systems that may not meet the real needs of the users, or for which there are no appropriate business models or feasible stakeholder relationships.

To date, there has been little work specifically addressing what software reconfigurable radio systems will mean for end users. However, given that the enabling technologies required for reconfiguration are developing rapidly, it is vital that the technologists working

Figure 5.1 User-centered design

on this topic are provided with real insights into the key areas that need to be addressed if such systems are to meet the needs of future users. These insights will also help to avoid the potential risk of overwhelming users with unnecessary complexity. One of the first research initiatives to adopt such a user-centered approach was the European IST research project TRUST – Transparently Reconfigurable UbiquitouS Terminals – [10], which aimed to iden-tify user requirements not just for the end user, but for network operators as well.¹

5.1.2 The ‘Non-existence’ Problem

Whilst a user-centered approach within the design cycle of a computer-based system is fairly well prescribed, the use of such techniques within a research project aiming to define a future technology is prone to the ‘non-existence’ problem; that is, it is hard to get users to provide requirements for theoretical systems and functionalities. Coupled with this problem is the challenge of gathering user requirements for a system not to be used by a fairly homogenous user group, but for devices that could in fact be used by anyone, for a myriad of different purposes. These users are likely to vary immensely in their technical skills and comfort with technology. In a more typical example of user-centered design, say, of a new computerized system for a distribution company, it would be possible to observe users in their current activities, interview them, conduct task analyses, propose possible design solutions, and evaluate early prototypes with the future users of the new system. In this way, early user requirements can be formulated and refined, and passed to the system developers. Future skill requirements of the work force can also be described, and the training required for using the new system effectively can be formulated. Contrast this with the situation in which research-ers of software radio find themselves:

† there are no comparable systems today: this is not incremental design;

† the technology is potentially extremely complex, and difficult to describe;

† there are no prototype implementations;

† software radio may impact all mobile communication users; it is not intended for use just by highly skilled specialists;

† the technology is not being designed for use in discrete well-defined professional applica-tions, but rather for widespread everyday use by consumers.

We are trying to establish user requirements for a technology that will follow the introduc-tion of 3G systems, yet those systems themselves are only just entering the mass market at the current time. Users’ current and future needs will impact on the acceptability of 3G systems, which in turn will create new needs and expectations. This is known as the ‘task-artefact’

cycle [11].

A good example of this is the wired and mobile Internet. How could it be possible to explain to future mobile users of the Internet how these devices might work, and ask them to describe their requirements for such systems if they did not already have experience of both mobile phones and wired Internet access? Indeed, user experience with the wired Internet in no small way contributed to the disappointments experienced with the launch of wireless application protocol (WAP) mobile phones – user expectations had been based upon their much richer experience of the wired Internet. Early adopters of WAP technology thus

1The impact of software radio upon network operators is discussed in Chapter 6.

expected the same performance and ease of access to the Internet to be coupled with the convenience of their mobile phone. Unfortunately early WAP systems (pre-general packet radio services (pre-GPRS)) failed to live up to such high expectations.

To consider a contrasting example, the overwhelming success of the global system for mobile communications (GSM) short messaging service has created a new need for tools to enable fast textual input for instant messaging. Undoubtedly future multimedia messaging applications enabled by 3G technology will create needs for alternative new ways of inter-acting with devices.

Table 5.1 gives examples of today’s mobile and wireless usage, showing relationships between users, technology and activities.