Wired reports that customers will want to control exactly who knows where they are and when now that wireless companies can track a mobile phone's location.

Bell Labs says it has developed a network software engine that can let cell users be as picky as they choose about disclosing their whereabouts, a step that may help wireless companies introduce location-based services in a way customers will find handy rather than intrusive.

Under a federal mandate requiring that cell carriers be able to pinpoint the whereabouts of any customer who calls 911 during an emergency, expensive network upgrades have made wireless companies more anxious to deploy services that can exploit these new capabilities for a profit. Examples of such services would typically include the ability for restaurants and other businesses to send a solicitation by text message to a cell phone when its owner wanders within range of those merchants. Other applications might include the ability to locate co-workers and customers.

While many cell-phone users might like to be notified of a nearby eatery or find it helpful to let others keep track of their movements, most would rather not expose themselves to round-the-clock, everywhere-they-go surveillance. However, given the real-time requirements of transmitting information over a telephone network, it can be difficult to program a wide range of options for individuals to personalize preferences such as when, where and with whom to share location information. One solution is to hard-code a network database with an "on-off" switch that activates or deactivates a service, for instance, during a window of time with set hours such as peak and off-peak.

Bell Labs said it used a "rules-driven" approach to programming that can take personalization to a less-rigid level without bogging down the computing power of a network.