A German Web site enables users to check whether mobile phones are switched on and within reception range, without informing the phone subscribers who are being checked on.
The service, called SMS Gateway Ping, is offered as a Web demonstration by the Berlin startup company gate5 AG, which specializes in location-based wireless and Web applications.
The service is named for the ping (Packet Internet Groper) network utility, which determines whether a particular IP (Internet protocol) address is online by sending out a packet of information and waiting for a reply.
In gate5's version, the user enters a mobile phone number in a field and clicks a button marked "Ping," upon which the system responds, after a brief delay, with the message "The telephone is switched on," or "The telephone is switched off or has no reception." The window promises an automatic update every ten seconds, and indeed, a test showed that it quickly registered when a mobile phone which had been previously off was switched on.
The system works via the SMS (Short Message Service) protocol supported by GSM (Global System for Mobile communications) networks widely in use in Europe. A test showed the system works, at least, for numbers in Germany, the U.K., France, and the Netherlands.
Users are not informed that their phone is being "pinged," though a signal that can be picked up as a disturbance by nearby radio receivers indicates network activity on the part of the handset.
Staff at gate5 were not immediately available for comment.