A Child Tracking Watch That Uses GSM
By Eric Lin, Thu Jul 01 23:15:00 GMT 2004

Cambridge Positioning Systems has developed a method to more accurately determine handset location on GSM networks. Soon you'll use it to track your kid, but what about tracking your own location?


Using wireless technology to track children is all the rage these days. Companies have tried just about wireless standard to help parents keep track of their precious cargo: GPS, Wi-Fi, Bluetooth, RFID. Now Cambridge Positioning Systems and Xion have developed a watch that uses GSM technology to track children.

The watch, called Sentinel, uses an advanced GSM location engine that delivers more accurate results in urban areas than traditional cell tower identification systems. According to the makers, the new technology increases accuracy from 500 meters down to 100 meters. In dense cities where GPS often fails outdoors, let alone inside buildings, cellular based location makes sense. It's less accurate than GPS when out in the suburbs or rural areas, but often city parents are the ones who worry most for their child's safety.

Because the watch uses cellular technology, CPS and Xion were able to easily add additional safety features that haven't been feasible on other systems. The watch isn't just a locator, it's also a communication tool. While it isn't capable of voice calls, parents and children can communicate via SMS or MMS. Children can send a panic SMS from the watch to a parent's phone, or the watch can send an automated message in case of unauthorized removal. The watch can also warn parents if their child moves outside of a specific area. Parents can send messages to the watch as well. These kids won't have to teach ur mum 2 txt, they'll be keying in "Cindy, come bak 2 the playgrnd," before their child gets his first phone number.

The Sentinal is a tri-band device, so it should work in major cities around the world. Xion and Cambridge Positioning Systems have researched this product well, and it should be a boon to parents willing to augment their own senses with some wireless help. Even this new technology works as well as its makers claim, child locators should only be the tip of the iceberg. Why isn't CPS signing licensing agreements with the major mobile manufacturers to get this into handsets? Carriers and users are drooling over location based services, but the operators are finding it difficult to build out accurate positioning networks. A technology like would allow them to quickly implement reasonably accurate LBS with minimum costs.