Saturday, 6 February 2016

Future of BT?

Some has asked about splitting BT and the like, but I did have some thoughts.

I do think that the technology has moved on and a heck of a lot of the lines in the country are capable of getting VDSL from the cabinet now. (Fibre To The Cabinet, Infinity, etc)

It seems odd that we even have a copper pair to the exchange - makes more sense to be the cabinet with an MSAN but sold by the likes of Openreach to any CP connection at the exchange with SIP for voice and ethernet port/VLAN for data. Why have a copper part to the exchange at all. Do an "outside the exchange" cab for direct exchange lines even.

In some ways new SOGEA will get close, but not offering the voice on the pair. And to some extent the idea of data only connectivity is sensible in the long term. However, there are silly people wanting old fashioned copper pairs to something I guess for a while.

I think the problem may have been regulatory - what you need there is OR to be operating this as a non-profit maybe. Though you have to work out where the capital investment comes in.

This seems more sensible than sub-loop unbundling to me. And could move on to FTTP or DP based DSL in the same way - hand over at the exchange as ethernet with SIP and all sorted.

Sorry if too technical - just a bit if techy rant this time.

30 comments:

  1. I think the pair back to the exchange is needed for automated loop testing and diagnostics. It's also a much more reliable voice service for 999 calls.

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    1. Loop testing could be a feature of the cab kit. 999 is very old concept and need massively updating including 999 being an API/XML standard not a a copper pair thing...

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    2. What I think David meant regarding 999 calls is that the Exchanges have UPS/generators so if there is a power failure near the exchange or near the end user, people can still call 999. Switching to a "no-copper" solution means either each cabinet would need its own UPS solution and then somehow getting that to the end users equipment to ensure 999 is available all the time.

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    3. I think power is a tad more reliable than it used to be.

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    4. I'd need to check the most recent Ofcom figures to know whether we are in a minority of quite what size, but we haven't had a phone connected to our copper pair for almost 10 years now - just mobile service and, more recently, SIP. The protection offered by power-down-the-line is increasingly scarce.

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    5. Indeed, the whole way 999 works is out of date in my opinion.

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    6. The question is -- in an emergency situation, is power likely to be down? I suspect the answer is often yes. In particular, there are some people for whom the loss of mains power *is* an emergency. These people are supposed to notify the emergency services in advance, but they don't, always: calls do come in from such people when there are large-scale power outages. Thus, problems up to and including deaths really are are plausible and I might even say likely if power is required to make emergency calls.

      999 should remain as simple as possible, with as few requirements as possible on the caller side.

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    7. Yes, but 999 only comes with a service offering voice calls, and then only can offer power backup where it is not an "over the top" one using some other service.

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    8. "I think power is a tad more reliable than it used to be."

      Speaking as a BT power planner, you'd be surprised :)

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  2. Do you think that, if a company had to operate the access network on a not for profit basis, there would be sufficient incentive to invent in trying new technologies? I wonder if there is a risk that doing this might have the opposite effect than the one which you want, and actually impede progress?

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  3. Didn't we once have a not-for-profit telephone company called the GPO?

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    1. And it was the failings of that which led us to where we are today :)

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    2. Well, how do you make an organisation with interests in investing in infrastructure, providing impartial services to all CPs, and not ripping people off? I hate to say it, but sounds like nationalising the raw infrastructure is the answer. Hmmm

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    3. Balanced against this is the risk that the structure does not incentivise infrastructure investment and quickly leaves everything lagging. I don't think that there's an easy answer here!

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    4. > sounds like nationalising the raw infrastructure is the answer

      Yup. Sanity regained.

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  4. The power cut case needs to be seriouly considered. With the copper pair all you need is a basic wired phone and the exchange takes care of everything else in a power cut. Mobiles, batteries (in the phone and the cell tower), voip etc all need a lot more things to have working battery backup power. I don't know of anyone who's home broadband stays up in a power cut.

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    1. Well, maybe. There is no absolute requirement to have 999 access in your home, or to have it 100% of the time. It is perfectly valid to have no phone service at all. Yes, it is useful, but these days in most places mobiles do work, power does work, and the cases where you could not actually call 999 would be very rare anyway.

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    2. Cabinets do have batteries as well as I understand it - so if they did do an old fashioned phone service on the pair it would work for a short period in a power cut. When not using old fashioned copper pairs, as SoGEA will not be, there is no requirement for 999 service to be available (though technically ensuring "access" to 116000 is a requirement?!?) so it is not a problem. 999 over VoIP is an over the top service where VoIP provider is not responsible for the underlying transport means.

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    3. There is indeed no requirement to have 999 in your home, but the people for whom power cuts are in and of themselves an emergency situation will have 999 in their home. (I work with such a person. They're not as rare as all that. A major case is that a great many medical devices require power at least intermittently for charging, and some of these are both essential for life and meant to be used for a very long time. My co-worker can at least drive to a hospital when needed, but at least once in the past the streets were impassable due to ridiculous amounts of snow: IIRC the 911 call -- this being in the States -- led to a helicopter being dispatched, or something like that...)

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    4. What do readers think will happen to cellular network coverage and capacity in an area where there's a wide area power failure? Especially given that the powercut would likely tend to increase the number of folks trying to make phone calls.

      In a great many densely populated places, small local cells hidden in street furniture and what have you are used to provide extra capacity and better coverage. Do they (and their connectivity) have worthwhile power backup?

      Are modern exchanges still capable of running off 48vDC for a decent length of time when the mains fails? Cable and LLU as well as BT Classic?

      Getting rid altogether of line-powered phone capability would seem, to me, a bit premature, IF the supporting infrastructure is still there.

      Once there's a properly enforced USO for cellular coverage and reliability (and for pigs flying), then maybe we can talk about phasing out the landline USO, and the need for 999 calls can go to mobiles rather than landlines. And then there's all the fun of reliable number-to-location mechanisms for the emergency services (E911?) - is that sorted yet?

      "I don't know of anyone who's home broadband stays up in a power cut."

      Mine does. UPS for various low-power gubbins including router/AP, DECT basestation, and other bits. Laptop runs on battery anyway. Not sure what happens if the power cut wasn't just local to the house. Didn't spend any money on it, just repurposed a UPS that had become outdated.

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    5. In my experience, you lose 3G but not 2G or 4G in a big power cut.

      VoLTE is capable of handling a huge number of calls per cell; note that 21CN Voice and other such high capacity solutions for the copper network are VoLTE repurposed to have ATAs instead of an LTE network.

      Plus, the last time I lost power at work, the local exchange refused to handle calls, but my mobile still worked.

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  5. I'd rather like to see a reversion to the old Surftime approach actually - we pay BT (or some other copper-rental operator) for a connection to an exchange somewhere. Then we pay somebody with a connection to that exchange to take my traffic between there and the Internet.

    We have that now, except bundled by the ISP; splitting it would simplify responsibility and make pricing more transparent IMO. If I pay BT £20/month for "80/20 VDSL to the exchange" and A&A another £20/month for the Internet transit, and my VDSL link fails, that's a BT problem for BT to fix, nothing to do with the ISP. (Plus we get options like having a second ISP available, or a direct connection to the work network, etc.)

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    1. Absolutely - the technical mechanisms are mostly there already - on VDSL it could be VLAN attached to more than one ISP. Via BTW it is realm based on PPP. I think ADSL and VDSL should both be Ethernet services (i.e. include modem, perhaps in larger face plate) and connected at Ethernet to ISP in exchange. Very clear responsibility for faults and no middlemen in fixing them.

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  6. ISDN2 (for fax) and redcare are two reasons that come to mind for keeping copper to the exchange.

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  7. > Do an "outside the exchange" cab for direct exchange lines even.

    Living across the road from an exchange, I would kill for this. Sadly I can't see anyone ever paying for it, so it's 24mbps "up to 18mbps" ADSL or Virgin until BT decide to mainstream FTTP. Even then, I think it's likely they'll go for a cab-based approach leaving direct exchange lines with the future equivalent of dialup.

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  8. Actually BT have already been installing precisely that - the exchange near work now has four brand new FTTC cabinets right outside it. FTTP is almost cab based (there's a fibre distribution point, usually right under an FTTC cabinet) - but the limitation with EO lines is an RF spectrum one that prevents BT putting VDSL kit inside the exchange buildings, and that wouldn't apply to FTTP optical kit anyway.

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    1. From what I can tell, BT will do it in areas with 100s of EO lines, or out in the sticks where they get government money to implement that in rural areas. If you're one of about 30 EO lines in a town otherwise covered by FTTC, there's no economic reason for them to do anything, so I'm not hopeful in any way

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  9. One thing to remember is the reliability of power depends on spare capacity - we are getting dangerously close to demand exceeding capacity on the power generation side of things nationally with power station closures and no replacements on stream yet.

    http://uk.reuters.com/article/column-kemp-britain-blackouts-idUKL5N0F42P120130628

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