Ordinary telephone lines can now carry signals from household and business alarms without interrupting voice transmissions--thus saving the cost of installing and maintaining a special telephone line dedicated to the security service.
The Public Utilities Commission last week approved tariffs enabling Pacific Bell to expand the new service, which has been limited to San Francisco and parts of Los Angeles.
By the end of next month, the company expects to be able to offer the service, called Pacific Bell Poll Star, throughout the Los Angeles metropolitan area and in metropolitan San Diego.
Poll Star service is sold to dealers offering burglary, fire, smoke and flood alarms and other monitoring functions--not to individual residential or business telephone customers, said Tatiana Fassieux, product manager.
Customers will be offered a package that includes purchase, installation and monitoring of the alarm-service equipment.
It is not necessary under this technology to add the cost of installing and maintaining an additional telephone line.
Until now, installing a special private line from a home to a security-monitoring service would cost $358, plus $75 a month, assuming that the distance between home and service was 10 miles; the monthly charge would increase as the distance increased.
Under a revised Poll Star tariff that Pacific Bell expects to offer starting Tuesday, installation will cost $92, plus $5.75 a month, according to Pacific Bell spokesman Larry Mobbs.
"While businesses have been the predominate users of alarm services because of the cost, we think Pacific Bell Poll Star will make such services affordable to a large segment of homeowners," Fassieux said.
Poll Star uses a technology known as "derived local channel" to superimpose alarm signals on standard telephone lines at a frequency below the rates used for voice conversations, according to the company.
This allows both types of signals to travel over the same lines simultaneously without interfererence. Alarm signals are received by scanners at Pacific Bell's central switching offices, where a computer alerts the alarm company.
If the phone line is cut, the equipment tampered with or power lost, the system automatically alerts the alarm company, according to Pacific Bell, a unit of San Francisco-based Pacific Telesis Group.
Within a month, Pacific Bell expects to have "at least a dozen" security companies offering Poll Star in their alarm packages in the Los Angeles area, with another seven serving Orange County and San Diego, Mobbs said.
Among those offering it now are ElectroSecurity and Western Pacific Monitoring in Van Nuys and National Alarm Computer Center in Santa Ana.