Cable and phone companies voiced worry about BPL interfering with...

poles is to other broadband equipment. The Canadian Cable & Telecom Assn. (CCTA) said BPL operating in the 2-80 MHz band could harm cable upstream broadband data services, including Internet access, telephony and interactive set-top boxes’ return channel. Cable is designed as a closed system immune to outside RF interference, but it doesn’t work that way, CCTA said, warning that if BPL emissions aren’t curbed, cable phone and even 911 service could suffer. And the problem won’t be confined to cable, but will affect all VoIP subscribers, it said. CCTA wants BPL under rules akin to Industry Canada-imposed cable leakage controls that require periodic testing and reporting. Citing bans by some govts. on BPL systems and conditions imposed by others on BPL trials and deployments, CCTA urged a “cautious approach” by Canada in setting BPL deployment rules. Bell Canada said BPL interference could degrade DSL quality. Since power lines aren’t shielded, RF energy radiations can cause interference with authorized radio and nonradio services, the Bell Wireless Alliance said. Of particular concern, it said: Interference with phone networks carrying DSL and VDSL services. About 240 TV transmitters operate in the 54-80 MHz band, a frequency in which BPL may radiate signals, said the Canadian Assn. of Bcstrs. (CAB). Industry Canada needs a new interference- causing equipment standard (ICES) for BPL and should require makers to demonstrate compliance through certification, CAB said. It also wants to require BPL operators to ensure their systems will comply “in all places and at all times” with radiation limits.