Monitoring of the TasTel, a subsidiary of electricity distributor Aurora Energy in Australia, BPL trial by a local amateur radio operator has revealed that the system is radiating signals on the 2, 6, 8, 12 and 16 MHz radio-telephone and DSC (digital selective calling) distress and safety channels.
These channels are used by ships to send and receive distress alerts, said Glenn Dunstan, director of the WIA.
"If the BPL enabled power lines pass by a marine radio station (they don't at the moment), the interference from the BPL signals will block reception of distress messages from ships.
"The point is that it appears Aurora are in breach of the ACMA BPL trial guidelines, which specifically prohibit BPL from radiating signals on marine distress and safety channels."
Aurora Energy business development manager, Piero Peroni, dismissed the latest findings as "rubbish".
"Unless a boat sailed under the power lines there won't be interference."
He said the trial was able to "notch out" certain frequencies used by emergency services. This allowed TasTel to avoid transmitting over certain frequencies.
Peroni said the only independent voice in the trial was the regulator, Australian Communications and Media Authority (ACMA), who are monitoring the trial closely.
"A handful of operators will continue to be against the product. But the important thing is we all have an open relationship with the ACMA."
Dunstan said the ramifications could be serious.
"If the signals are not supposed to be radiated now, how can BPL providers guarantee that they will not be radiated from a system which does pass by a coast radio station?
"It will be too late to address this problem when a distress signal is blocked by BPL...."
Despite these concerns the TasTel trial, which delivers broadband speeds up to 200Mbps, is moving at pace with commercialization possible before the year is out.
"We are in the process of developing a plan of where we may take it. There will be an announcement in the next four to five months," said Peroni.
The BPL trial was launched by TasTel in September last year in the suburb of Tolmans Hill, at the foothills of Mt Wellington, near Hobart in Tasmania. In December, it was extended to selected areas of the regional city of Burnie.
"The penetration [subscribers] rate is outstanding. We are more than happy with it. It is more than we expected," Peroni said.
Because the trial has used "bleeding edge" technology from its partner Mitsubishi, it has not been without its glitches. "It has been painful at times. We have changed a lot of our techniques, but we have constantly been progressing."
Pricing for the plans starts from A$14.95 (US$11) right up to A$79.95. All trial customers get a free modem and no contract.