Increasing number of mobile portable devices in use creates a great opportunity for development of a wide spectrum of mobile information services. The main advantage of these services is their high availability to customers anytime and everywhere [1,2]. In particular, development of such technology as WAP [11,17,19] (and other novel mobile communication technology) makes it possible to provide users of cellular phones with access to the Internet and, as a consequence, to use services which earlier were available only via PCs connected to the Internet (see Figure 1).
Figure 1. Mobile information services
However mobile devices, like cellular phones and PDAs, have severe restrictions that might complicate practical use of information services. These restrictions related to the limitations of wireless data networks compare to wired networks (less bandwidth, more latency, less connection stability, less predictability and less standardized protocols) and to the limitations of mobile handsets compared to personal computers (small screen size, complicated text input, limited memory, slow CPU and more constrained energy supply).
Additional problems with wide application of mobile information services are related to higher cost of wireless communications (compared with wired communications), and to the assumption that most of customers using mobile devices are non-experienced Internet or PC users. This puts forward requirements to simplicity and expressiveness of the services. It is possible that some of the limitations will be relaxed in the future by development of hardware or telecommunication networks technology [14,15] but at the moment we should take them all into consideration when implementing mobile services.
As a basic way for relaxing the above-mentioned limitations and problems we see the following solutions:
precision of the information delivered to a mobile device should be very high - its amount should be as small as possible but sufficient enough to be useful to the user.
services should be personalized - they should take into account changing customer preferences
services should be able to adopt both to changes in the customers preferences and in the context of communication
The way of how, for example, WAP-based services are now supported by some service providers [21,22] is to propose some fixed set of services and to make them available on-line via WAP-handset menu. However dynamic personalization and adaptation of services to customer and communication context is not enough addressed yet.
We think that a novel solution to mobile service provision should be based on assumption that as much as possible work for service customization and provision should be done off-line without direct participation of the user of mobile device.