Generators

[The Natural Philosopher]

[tony sayer]

In article , John Walliker scribeth thus

I've been in Orange and Voda base stations and some have rather f*ck off sized batteries. I think you'll now find that as BT move to Fibre from the roadside cabinet they will have to power that gear by whatever means they choose to and if thats the local mains or streetlight feed then if thats cut of then they will need either backup power from batteries and or their own cabling network....

[dennis]

The current telephony cabinets are just connection points and do not need extra power.

The 21cn cabinets are effectively a part of the exchange and need power and backup.. they can terminate the phone lines and the various broad bands.

[tony sayer]

Do bear in mind that Dave as many will know, lives in a rather remote area and that his experience of mobile networks may not be the same as those in more populated areas;).

The few times I've lost mobile coverage has been what they have a wide area whoopsie with their switching centres and areas that have no coverage as they deem it too expensive to go there...

[Andy Burns]

Why do you keep insisting that the PSTN part of an FTTC line terminates in the cab? It doesn't, it merely passes through it and continues over copper all the way back to the exchange ...

[polygonum]

Thanks - that was what I was trying to get answered. So the PSTN side is, in practical terms, the same as ever? (Albeit with some splitter mechanism to separate/merge the data.)

[Andy Burns]

Yes, with ADSL looking from your house back toward the exchange, your line is jumpered straight through the old cab.

+--------+ | | | | | | |exchange| | | | | +-------+ +-----+ | |

[charles]

the demo one in the OpenReach van certainly had back up batteries installed. At the presentation I attended last week, a speaker was talking about 4 hours worth.

[charles]

Then it needs some way of getting the DSL signal off the fibre and adding them to the PSTN feed to the house. So, it needs power.

[Jules Richardson]

Over here, our cable company fitted a UPS for the gubbins that provides connectivity - I think because it provides our phone service too, and there's a legal requirement that their equipment won't prevent emergency calls from being made during a power cut.

Of course they put the kit in five years ago, and the UPS battery is probably snafu by now because they've never been back to test/exchange it, implying that the law perhaps only applies at the point of installation :-)

cheers

Jules

[polygonum]

Thanks - that is as I had imagined it. But there was a doubt in my mind

- allowing the possibility that the copper-pstn link from old cab to exchange was being replaced by an ADC/DAC and then carried over fibre to the exchange.

[Andy Burns]

Yes, the cabinet does need power to keep the DSL part of your line working, but not the PSTN part which is what was under discussion.

[Grimly Curmudgeon]

I was still dealing with them 20 years later as some parts of the southern Highlands didn't yet have mains power or the owners weren't prepared to be stiffed for £K*many for the supply. The economics of running one were frightening compared to a pole supply and it amazed me that the REC didn't offer subsidies or loans to potential customers, for it would have been sensible long-term.

[Dave Liquorice]

True but this is FTTP ie the fibre comes into the building not a street box half a mile away... The ONT does need power but as that comes from a wall wart in the premises that can be feed from the UPS that is keeping everything else up. Or not if there is no need for the connection during a black out...

You can also get power supplies for ONTs that have battery back up. In some places FTTP is replacing copper as the primary connection so to maintain the abilty to make emergency calls during a blackout backup power has to be provided. They can signal battery status back to the network operator so it can be replaced when it starts to die, as in reaches end of life not flat due to blackout. B-)

[Dave Liquorice]

Assuming you have enough time to recharge them safely/sensibly when you do have power.

IIRC is was 3 hrs off at least once a day if not twice.

[Dave Liquorice]

Doesn't make any difference with a load shedding blackout that takes a whole area (town, city suburb) off grid. Load shedding is very different to a local distribution fault that affects just few hundred customers and a cell or two.

Maybe I do have a skewed perception of mobiles, 2G and 3G are present provided you are upstairs on the right side of the house (2G one side, 3G the other) and near a window, but even then they aren't really useable, there is no DAB, only 3 Freeview multiplexes, cable TV nope, LLU nope, FTTC nope. FTTP yes going in now in the town but it's a self help community system.

I meet enough people who live in more populated areas who take all of the above for granted, almost a right. They will be in for a bit of shock if load shedding is required... Indeed the first time the power to the local cell went off here after mobiles started to become popular and people dropped their land lines, (no ADSL available then, community ISP uses wireless), many people found themselves incommunicado for several days. One network came back with the power, two others fairly quickly (hours), but one was off for >48hrs after the power was restored.

[tony sayer]

Well as a sound man your not missing that much, give your ears a rest;!...

Dab sounds s**te apart from BBC R3 and thats not that wonderful..

Don't you have freesat at all?. Its fine here and I'd expect it'd be good up there too;!...

Well if needs must, can't they do that by microwave distribution up there which is being done in some areas down here?..

Well thats long enough to get to bed early which ISTR is Homo Sapiens standard response;?>..

[dennis]

Why don't you understand that BT is moving away from centralised exchanges and the technology is being installed to allow it?

I have worked on DSLAM cards that terminate POTS. They had 2m lines in and looked like a concentrator or ethernet and they terminated as VoIP and worked with a softswitch.

And BTW I never said FTTC is anything to do with PSTN. FTTC is just an interim step.

[Andy Burns]

I'm sure that is the way they *will* go, eventually either the FTTC cabs will include the equivalent of line cards for delivering PSTN to the home, or they'll allow SIP presentation for home users the same way they now offer it for businesses.

But what they have been doing for the past 3 years and probably will for the next 5 or more is not that!

So you've said, but BT didn't buy from "you" and they aren't installing equivalents from anyone else.

OK, so in what way are the 21cn cabinets effectively a part of the exchange and [...] they can terminate the phone lines ?

[Andy Champ]

The bit that muxes the DSL signal into the line, and carefully doesn't send it the wrong way to the exchange - it will allow POTS through without power won't it?

Andy