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Conclusions and Future Directions

In document Software define radio CRN.pdf (Page 184-188)

Kate Cook

5.6 Conclusions and Future Directions

A user-centered approach can add significant value to the research, design, and development of future generations of mobile communication systems enabled by technologies such as software radio. User needs must be identified and understood if the full potential of such technologies is to be realized – successful products will be those that are useful (they apply the technology to enable users to achieve their goals) and are usable (easy to use). There are many user-related questions relating to software radio yet to be answered; this chapter has sought to present one approach to developing an understanding of the user’s perspective of software radio.

The first phase of this approach focused upon eliciting initial requirements for software radio from Lead Users of analogous mobile devices. This approach was adopted in order that some of the difficulties in describing a complex and ubiquitous technology such as software radio to users could be overcome. A summary of these initial requirements was provided in this chapter; a complete description of the process and resulting requirements analysis can be found in Ref. [2], which also reviewed a number of secondary data sources. The following conclusions were drawn from these studies:

† SDR-supported mobile devices and services will only be attractive to users if they fulfill a need which cannot be satisfied by other means;

† SDR will succeed as an enabling technology if it supports the key wireless advantages of global portability and user intimacy;

† services supported by SDR must be designed in such a way that the key barriers to mobile uptake are addressed, namely: absolute simplicity, reliability, affordability, personal rele-vance;

† quality of service needs will be task- rather than application-dependent;

† the user sees the terminal and network as one interface; deficiencies in one will impact the perception of the other;

† care must be taken in the design of products and services such that they integrate with social activities in the home environment;

† requirements for SDR are highly contextualized by the technology and the usage environ-ments; this makes the requirements capture process difficult.

The initial requirements were drawn from the Lead User group; even within this group, however, the results showed a diversity of needs and attitudes. These initial requirements can be summarized into two broad categories of business and personal requirements for software radio.

Business requirements:

† cost is not important

† high-quality images (frame rate and resolution, high data rate) will be important

† will need coverage and immediate access to services

† business services required will include local information and translation

† productivity applications and time-fillers (e.g. games) are likely candidates for software download

Personal requirements:

† best cost and quality (voice, image, bit rate) combination is important

† user has time to play around with the device, particularly for personalization

† user is willing to compromise quality for cost

† service purchasing decisions are ad hoc

† user is conscious of network provider brand image

† simple messaging services and location-aware services are important

The Lead User approach was extremely useful in the first phase of this user-centered research as it provided a recruitment template for participants for the questionnaire, inter-view, and focus group studies. It was considered that only this type of user would be likely to understand the flexibility of use that software radio will enable, by considering and describing their current activities with analogous devices. However, after this initial phase of research and the identification of initial requirements, the focus of study was expanded beyond this narrowly defined user group. One of the risks of investigating only Lead Users is that the results and conclusions are based upon only a small section of the population, whereas software radio will become a ubiquitous technology ultimately used across the whole spec-trum of users with varying skills and comfort with technology. It is therefore important to consider a wider range of users in the next phase of this research.

The second phase of the research thus focused upon developing a small number of core user scenarios that were explored in greater detail. The main advantage of using scenarios is that context can be provided to the end user, which enhances their understanding of the concepts involved. We have found that the scenarios have proved to be useful not just for exploring user requirements with end users, but also for considering the implications of software radio for the network operator (see Chapter 6). The scenarios have also enabled researchers to discuss assumptions that were being made, and to clarify a number of technical issues with regard to the overall system architecture.

To some extent, more questions have been generated than answers. It is hoped that some of these questions will be answered in the final phase of user research within TRUST, and that other research will answer yet more of these. The research described herein has been a useful first step in demonstrating how a user-centered approach can provide a focus for the research and development of future technologies such as software radio. The full benefits of such an approach will only become evident much later on.

One of the challenges for user-centered research in this field is the fact that mobile communications technologies are evolving rapidly. We are asking end users and network operators to consider future products enabled by SDR when their understanding of emerging 3G technologies is not yet mature or in many cases even existent – users’ perspective of SDR is likely to evolve as and when they gain more experience with these new 3G systems. Users’

expectations are shaped by their current experience with today’s technologies, and so our requirements will need to be revisited once these technologies become more mature and are in widespread use. In practice, many of the user issues that have been identified through the research to date may prove equally relevant to the 3G systems now being deployed, and are likely to be of value to 3G developers even in the shorter term.

Acknowledgements

This work has been performed within the framework of the IST project IST-1999-12070 TRUST, which is partly funded by the European Union. The author would like to acknowledge the fruitful discussions on technology issues, and other contributions from

her colleagues from Siemens AG, France Te´le´com – CNET, Centre Suisse d’Electronique et de Microtechnique S.A., King’s College London, Motorola Ltd, Panasonic European Laboratories GmbH, Telefonica Investigacion Y Desarrollo S.A. Unipersonal, Toshiba Research Europe Ltd, TTI Norte S.L., University of Bristol, University of Southampton.

The author would also like to acknowledge the contribution of Dr David Williams, formerly of Motorola UK Research Laboratory, who conducted the first phase of the user research described herein.

References

[1] Beach, M.A., Pereira, J., Swain, R.S. and Munro, A.T., ‘Reconfigurable radio systems and networks’, IEE 3G Conference, London, 2000.

[2] Williams, D., Ballesteros, E., Martı´nez, C. and Morata, E., ‘User assessment: reconfiguration scenarios and requirements’, Public Deliverable D2.1 from the TRUST Project (IST-1999-12070), 2000.

[3] Vaananen, K., Mattila, V. and Ruuska, S., ‘User needs for mobile communications devices: requirements gathering and analysis through contextual inquiry’, in Johnson, C. (Ed.)Proceedings of the First Workshop on Human Computer Interaction with Mobile Devices, GIST Technical Report G98-1, May 21–23, 1988, Dept.

of Computing Science, University of Glasgow, Scotland.

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[5] Kaikkonon, A. and Williams, D., ‘Designing usable mobile services’, Tutorial at ACM SIGCHI 2000, Amster-dam, The Netherlands, 2000.

[6] Marturano, L. and Wheatley, D.J., ‘User-centred research in Motorola’,Adjunct Proceedings to ACM SIGCHI 2000, ACM Press, New York, 2000, pp. 221–222.

[7] Schuler, D. and Namioka, A.,Participatory Design: Principles and Practices, Lawrence Erlbaum Associates, New Jersey, 1993.

[8] Holzblatt, K. and Beyer, H.,Contextual Design: Defining Customer Centred Needs, Morgan Kaufman, San Francisco, CA, 1998.

[9] Carroll, J.M., Making Use. Scenario-based Design of Human–Computer Interactions, MIT, Cambridge, Massa-chusetts, 2000.

[10] TRUST (Transparently Reconfigurable UbiquitouS Terminals) – IST-1999-12070.

[11] Norman, D., ‘Cognitive engineering’, in Norman, D. and Draper, S.W. (Eds)User Centred System Design, Lawrence Erlbaum, New Jersey, 1986.

[12] 3GPP, ‘Technical Specification Group (TSG) terminals; multimode UE issues’, TR21.910 V1.3.2, 1999.

[13] Williams, D., Cook, K., Ballesteros, E., Martı´nez, C. and Morata, E., ‘‘‘Anything you want it to be’’: end-user and operator requirements for Reconfigurable Mobile Communications,Proceedings of IST Summit 2000, 2000.

[14] UMTS Forum, ‘The future mobile market: global trends and developments with a focus on Western Europe’, UMTS Forum Report 8, March 2000.

[15] Ovum, ‘Third generation mobile: market strategies’, Ovum Research Report, 1999.

[16] ISO FDIS 13407, ‘Human centred design for interactive systems’.

[17] Urban, G.L. and Hippel, E., ‘Lead user analyses for the development of new industrial products’,Management Science, Vol. 34, No. 5, 1988, pp. 569–582.

[18] Olaziregi, N., Niedermeier, C., Schmid, R., Bourse, D., Farnham, T., Haines, R. and Berzosa, F., ‘Overall system architecture for reconfigurable terminals’, IST Mobile Summit 2001, Barcelona, Spain, September 2001.

6

Software Radio: The Mobile

In document Software define radio CRN.pdf (Page 184-188)