Fibre & Copper Service Availability Phone Lines

In the "olden days" we were told that in the event of a mains power supply our phone lines should remain working for at least 2-3 days powered by the backup power source at the exchange (usually lead acid batteries). That meant that we were able to make emergency calls and (for a while) keep in touch with friends and relatives.

Currently (December 2021) there are a very large number of communities in the north of the UK who have been without mains power for many days following wind and snow storms. They are also unable to get mobile signals due to that infrastructure being down as well. Assuming their landline phone apparatus is not cordless or mains powered should they be able to at least make basic phone calls as in the "olden days" or have exchanges lost their short term backup supplies due to technology improvements?

Do fibre circuits maintain at least a dial service, subject of course to a standby supply to power any handheld phone sets?

The phone network is in transition. By the end of 2025, all traditional exchange-based telephony will be gone. That is, there will be no dial-tone generated from the exchange.

At that point, people will have digital broadband connections only, which could be either:
* FTTP (fibre, driven from larger "head end" exchanges)
* FTTC (copper, served by DSLAMs in cabinets)

"Land line" voice service will be done as voice-over-IP over the broadband. "Dial tone" will originate from your local ISP-supplied router. The smaller exchanges will be shut down completely.

Both cases depend on power being available at the customer premise, to power their router (and ONT for FTTP). The customer can protect themselves with a UPS, as you are already aware. Maybe in the long term, people will use the batteries in their electric cars.

Apart from that, people served by FTTP will be in a good position. The head-end exchanges are well protected with generators that can last for many days, so service will be reliable. The entire fibre network between the head-end exchange and the customer is passive, i.e. nothing in between is powered.

Those who remain on FTTC will be less-well served. The cabinets do have battery backup, but maybe only for 12-24 hours.

Of course, if the power lines are down, there's a pretty good chance that overhead comms lines will be down too.

Edited by candlerb (Mon 06-Dec-21 16:39:28)

I wonder if a lot of these rural homes are served by overhead lines. In which case they will have gone the same way as the power lines - downed by a tree.
I also think there's been more outages of power and phone lines as its unusual for a storm of this strength to hit the east. Over in the west, weak trees don't stand so long!

Back at the start of FTTP the ONT supplied had a battery back up. Naturally a sensible idea like that was soon knocked on the head, no doubt they cost OR 50p extra.

I don't think it's the 50p for the battery backup which was the issue. I think it's because Openreach didn't want to be in the business of providing a national voice network, with declining traffic and revenue, and costing a bomb to run.

Like it or not - most people don't even use their land line these days.

In reply to a post by candlerb:

I think it's because Openreach didn't want to be in the business of providing a national voice network, with declining traffic and revenue, and costing a bomb to run.

Ah, hadn't seen it that way.

But rural folk, and some older people do need and or want a landline. There needs to be more information and options for these people to stay connected during a [normal] power cut.

I live in a rural area, and we do get power cuts. I use 4G broadband and VoIP, and also have mobile phones of course.
I have UPS which lasts about an hour - however I've discovered that the nearby cell tower (which provides our 4G as well as phone signal) only lasts 35-45 minutes when we have a power cut - then we don't even have emergency mobile coverage unless we go some distance along the road.

Thank you both Woolwich and Candlerb for good explanations. Certainly for me in deepest Sussex(!) there are several friends who are in mobile blackspots (with 2 on emergency callout services) and have to rely on their copper links to keep in touch.

For me it's good to know VoIP is likely to maintain at least a voice service, subject of course for me providing a UPS. I have been studying the BT press releases/documentation to try and get to the bottom of this whole technical area and it's woefully lacking. It is also necessary for the digital wireless/mobile services to consider how to link messages (at least emergency ones) into the fibre carriers too to overcome black spots/blackouts.

In reply to a post by Woolwich:

In reply to a post by candlerb:

I think it's because Openreach didn't want to be in the business of providing a national voice network, with declining traffic and revenue, and costing a bomb to run.

Ah, hadn't seen it that way.

But rural folk, and some older people do need and or want a landline. There needs to be more information and options for these people to stay connected during a [normal] power cut.

I jacked in our physical landline (rural Suffolk) after it became so unreliable it was past a joke.

The last straw was when Openreach 'fixed' the line for the campsite down the road except they they re-jumpered everything out by one or two - so my inbound calls went to the campsite, I got calls for my 95 year old neighbour up the road (who's family was distraught because they couldn't call her back)....absolute 'mare. Took about a week to sort....

From then on in my "landline" (actually VoIP) was very reliably carried by mobile broadband (external antenna on the chimney, Huawei router in the loft) via newly upgraded local EE mast serving 4G, ironically barely a fee hundred metres from the BT research HQ at Adastral Park...

FTTP came after that. But we still have lots of trees and 34-odd poles spans of aerial fibre, so we have backup comms and backup power.

You're only ever one storm away from no power and/or no phone so best make alternative arrangements if it matters.

I guess in the next "few weeks" when EVERYBODY has real fibre to every property we'll all feel that we really are world beaters! 😆😆😆