There is a simple high-level view of the environment in which LBMS are delivered and consumed. A mobile terminal (phone, PDA, or in-car device) is able to communicate wirelessly with other network nodes. It is also able to determine its physical location on the earth s surface. The connectivity enables interaction with a mobile or navigation service provider and most of the navigation services are controlled in some way by the position of the mobile terminal.
Coherence between the modeled world and the real (physical) world
The essential capability needed to deliver useful and accurate location-based services is to link the location of the person in the real world to a position within a model of the real world, which is used to compute responses to requests for information about mobility in the real world. Computing happens on the model. The person carries out the activity in the real world. Positioning via some locations technology allows the person and the computation to be coordinated or to be coherent. Coherence is the hallmark of location-based services that seem natural, useful, and correct to mobile users. Let s take a look at the components and see how world-model coherence can be achieved with technology in the field today.
Simple model: Mobile person with connected device
First, what part of the population of mobile devices has the potential to participate in LBMS? Let s look at the overall population of connected mobile devices such as phones, pagers, PDAs, and in-car systems. There are now more than ten million in-car navigation and telematics systems worldwide. More than half are in Japan and the bulk of the remainder is in Western Europe. There are a similar number of wirelessly connected PDAs and two-way pagers, with a more even distribution around the world. There are about a billion mobile phones, and these are also distributed more evenly geographically.
Only phones have reached the mass-market. And because the number of phones is so much larger than the combined total of other connected mobile devices, there is little reason to consider PDAs and two-way pagers except as delivery points for a few niche and high-value applications. In-car systems are even more specialized and expensive, although there are around 600 million personal vehicles in the world and almost 60 million new (replacement) vehicles produced worldwide each year. Many analysts believe that phones will absorb the PDA and two-way pager market, as costs come down and miniaturization combined with economies of scale make specialized devices ever less attractive.
Many car manufacturers are building at least rudimentary connectivity into all new car models, and it is likely that at least half of the personal vehicle population will be connected in the next ten years. In short, there are two large populations of connected mobile devices about a billion mobile telephone handsets and a few hundred million connected automobiles in the near future.
LBMS requires a data communications capability
Connectivity is not enough, however. You also need a data communications capability. Ideally, this should be a packet-switched networking capability identical with, or at least similar to, the IP networking possible on the Internet. A shorthand way to express this requirement is to use the term "wireless Internet", although there are other kinds of data capable networks that meet the needs of LBMS. Today there is a patchwork of different incompatible technologies for data communications between the fixed Internet and the mobile terminal. Hopefully, standard networking and internetworking will evolve just as in the case with the fixed IP-based Internet, but today different environments exist in the major markets: Japan, North America, and Western Europe.