Customer DSL Lines May Impede Alarm Signals Transmissions

According to Security Sales, alarm customers who subscribe to DSL service through their lo-cal telephone company may not be able to get an alarm signal through.

Security Sales learned about the possible problem during a meeting of the Security Industry Association's (SIA) Digital Communications Standards Subcommittee.

During the meeting, Dr. Jimmy Salinas of Southwestern Bell Telephone told representatives from alarm panel manufacturers -- including Ademco, DSC and Radionics -that DSL service may put noise on the line and effectively disable the alarm system from reporting.

For new panels, a possible solution involves placing a low-pass filter inside the unit. How-ever, such a task could take more than a year because Underwriters Laboratories (UL) may insist on testing the modified panels.

For locations with existing installs, a possible solution entails splitting the telephone line be-fore it reaches the residence and then running it to the panel. This approach would require countless service calls and could be extremely problematic when it comes to multiple-dwelling buildings.

SIA's subcommittee moderator L. Virginia Williams indicated that SIA is writing an official in-depth release on the topic. In addition, SIA is working with the Telecommunications Indus-try Association (TIA) to develop new standards for DSL.

We will keep you posted as we get more information on this subject.