For those of you who don't want your mobile operator to keep track of your whereabouts and flood you with unsolicited information, new software from Bell Laboratories gives you greater control over your privacy.

The technology allows mobile phone users to specify what location information they wish to share, when, with whom and under what criteria. It is the focus of a paper that Bell researchers plan to deliver at an international conference on mobile data management sponsored by the IEEE (Institute of Electrical and Electronics Engineers) in Berkeley, California.

The Bell Labs software aims to help real-time wireless communication providers and their customers cope with the conflicting demands of accessibility, personalisation and privacy. Numerous Europe and the US operators already offer a range of so-called location-based services, enabling them to track customers and feed them relevant local information about, for example, restaurants, movie theatres and retail stores. While some users appreciate such services, others prefer not to expose themselves to constant surveillance.

The Bell Labs system is analogous to someone querying a database. The request is checked against the user's preferences and filtered through a rules engine, known internally as "Houdini," before any action is taken. Because location-based services operate in near real-time, this entire process takes only a few milliseconds or less.

The technology, according to Bell, could appeal to numerous users, particularly in the corporate sector. Equipment vendors, for instance, may want to know the location of their technicians during regular working hours. In the evening, however, the technicians may prefer to disable location sharing with their boss, while others may see a need to enable important customers to see their location at anytime but within a limited area, say, of 10 miles.

The rules-driven approach of the Bell Labs system is designed to allow users to set their own preferences either on their computers or directly on their mobile phones.