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You can’t kill BPL if it’s already dead

January 13th, 2012 by · 3 Comments

This article was authored by John C. Tanner, and was originally posted on telecomasia.net.

Broadband over powerline is dead. Again.

At least it is in the US, where BPL service provider International Broadband Electric Communications (IBEC) – backed by IBM – announced this week it was shutting down services in the rural markets where it operates, according to FierceTelecom.

IBEC blamed the closure on the financial burden sustained from damage caused by tornadoes in April last year, but as FierceTelecom’s Sean Buckley observed:

While the tornadoes are indeed a valid reason for IBEC’s troubles, BPL was plagued with two key problems from the start: It was known to cause interference, and utilities weren’t exactly interested in competing with their pole-attached neighbors–the telcos and cable operators that already enjoy a duopoly on the broadband market.

Indeed, the US market is littered with the corpses of BPL services, some of which never got out of the trial stage. And of those that did, the most successful of the lot – a BPL network in Manassas, Virginia, initially run by COMTek – turned out its lights in April 2010, at which point tech sites like GigaOM and TechDirt declared BPL technology dead and gone and good riddance. It wasn’t quite dead, but IBEC was effectively the last man standing in the BPL sweepstakes.

And now it’s done.

Yet somehow – despite years lagging in development hell, being sidelined by the evolution of fiber and fixed/mobile wireless broadband technologies, and having never really gone anywhere despite dozens and dozens of trials in the US, Europe, Asia-Pacific and Africa – BPL still lives.

Granted, it lives in mutated form thanks to powerline technology still being developed and incorporated into things like home networking and smart grids. (Indeed, the HomePlug Alliance and the IEEE issued new specification announcements for both this week.)

But BPL also still survives as a residential access technology right here in Asia – Philippines incumbent PLDT and Manila Electric Co (Meralco) are currently testing BPL for a planned broadband access service for the 4.5 million customers connected to the Meralco grid.

What is it about BPL that keeps it going?

Possibly the original concept of BPL (electricity cables connecting homes to the power grid can be used as broadband access pipes to compete against the copper loop DSL monopolies!) is just one of those things that sounds so good on paper and works well enough in demos that some companies are still willing to give it a shot.

On the other hand, PLDT and Meralco been planning their BPL service since 2009, and despite plans to finish testing at the end of 2011, they’ve reportedly extended the test period into this year due to (wait for it) interference concerns. Even if the service goes commercial … well, see above.

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3 Comments So Far


  • Ed Hare, W1RFI says:

    I agree with your assessment that BPL will have its applications within buildings, but for the most part, the smart-grid companies are avoiding BPL. Companies like Ambient and Current Technologies, initially access BPL manufacturers, are now concentrating on designing smart-grid control applications, not BPL equipment. Every single aspect of BPL that plagued those companies that tried to use overhead and underground distribution lines to carry data signals to provide Internet access will experience the same problems trying to use that medium to carry data signals for grid control.

    To understand why this is so, go buy the best Ethernet conductor you can buy. Now, untwist it. Then separate the wires by 10 feet or more. Next, put them 30 feet in the air, outdoors in the rain. Then, connect those wires to all sorts of other wires and noisy loads that change on a minute-to-minute basis. That should work as well as the original wire, right? Not by any stretch. Although access BPL does provide some redundancy through multiple carriers and error correction, that can only go so far in overcoming the extreme constraints placed on the ability of those wires to carry data.

    What was not economical for access BPL will not be any more economical for smart-grid applications. What did not function well for access BPL will not function any better for smart-grid BPL — at least not on the distribution wiring. The reliability and latency needed by the utilities to control vital utility-equipment functions cannot be done with an interference prone mechanism like distribution access BPL.

    I have personally conducted tests of access BPL systems where we saw as little as 5 watts of nearby transmitter take it down, to the point where the BPL system had to reboot itself to function again. This cannot be used for utility purposes.

    Will BPL play a role in the development of the smart grid? I believe it will, but on the 240-volt side, not on the distribution side. As *reliable* signals are conducted around the grid using other more reliable means, those signals will have to get from the overhead and underground distribution system into homes and buildings. This will, in my opinion, be done with a combination of wireless and power-line communications.

    Will that be BPL? Maybe, maybe not, because to read meters, or accomplish demand-side management of power consumption, to name a couple of examples, one does not need to move a lot of data. This *can* be done reliably with slower-speed PLC, operating below 500 kHz on power lines. It can be done reliably at higher speeds using BPL on the 240 volt lines, although more attention needs to be paid to placement of modems, cross-phase coupling, etc.

    Don’t be too quick to think that changing the purpose of broadband data communication over power lines is somehow “reinventing” the technology. The bits are still the same bits whether used for Internet access or for smart grid applications and the limitations of the power grid as a conductor of high-speed, radio-frequency signals are still present.

    Albert Einstein said it best, when he warned that one does not solve problems by using the same thinking that created those problems in the first place.

    Ed Hare, W1RFI@arrl.org

    • fingers says:

      I guess you haven’t tested the right BPL modems. We all know ambient, current, corinex and even siemens are doomed to their BPL development.

      Try testing MainNet and PPC AG and see how reliable their systems are. You may also check their deployments.

      • Actually, “fingers,” I have tested Main.net modems for susceptibility to nearby transmitters. In the Main.net system that used to be deployed in Manassas, VA, similar effects to what I described in my posts were seen, albeit indirectly. When a nearby transmitter was activated, the system stopped sending data and when the transmitter was turned off, there were a few seconds of radio silence, followed by a cacaphony of noise as the system re-sent the data that had been lost.

        This is not as scientific as the more controlled tests that ARRL did with the operator of the Amperion deployment in Bowling Green, OH, but I have little doubt that the Main.net modems that were deployed in Manassas were just as susceptible as other systems tested.

        Newer Main.net modems may be improved, as it is technically feasible to design any electronic equipment with good immunity from interference. I have also participated in testing of other power-line systems, such as the Motorola BPL and Maxim PLC systems that were remarkably immune. I would welcome working with Main.net to test both the interference from and/or to their modems.

        As to being reliable, every Main.net system deployed in the US has been dismantled by the utility that tried to make it work out for them. No one can say for sure what balance of reliability, economics and radio interference issues caused the utility to abandon its foray into BPL.

        The bottom line to my post is that every factor that caused BPL to be an unviable approach for providing Internet access to end users also exists if that same technology is used to send the same bits to control utility equipment. There will be some application of power-line communications on the premise wiring inside buildings, but that will, overall, be a relatively small part of the smart-grid technology.

        Ed Hare, W1RFI@arrl.org

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