Squeezing Blood From A Rock…

or, How to Stretch Your Radio Spectrum

Theoretically, radio spectrum is an infinite resource. Practically, however, current technology restricts the amount of usable spectrum to a very finite and, as the recent FCC auction in the United States shows, very expensive range. Wireless manufacturers and operators therefore expend great effort to squeeze the maximum utility from each kilohertz of frequency.

One approach is a new trial service called Cellemetry. Offered by BellSouth, Cellemetry promises to provide a cost efficient way to perform telemetry functions such as reading utility meters and monitoring vending machines including copiers, soda machines, and alarms.

Cellemetry works by using existing capacity of the control channel found in all cellular networks. The control channel in an analog cellular system is there to register mobile phones that are roaming. When the customer roams and wishes to place a call, the cellular phone transmits a short message that includes a mobile identification number and electronic serial number over this control channel.

Cellemetry inserts its messages on this control channel. The system requires that a small radio be inserted into the target equipment that will be monitored. At preset times, the device can place a call to transmit the reading or, alternatively, it can be activated remotely to request a reading be sent.

BellSouth is initially testing Cellemetry in Indianapolis and expects it to be widely available as a commercial service in early 1996. Early testers include power and utility companies.

BellSouth Wireless
1100 Peachtree Street N.E.
Atlanta, GA 30309-4599
(404) 713-0585
(404)-249-0304 (fax)
http://www.bellsouth.com