2024-08-19

Power on the line

Who ensures you can call 999 in a power cut?

This blog does not have all the answers, it has a lot of questions, opinion, and some history. I am trying to address the issue and explain some of the technical, financial, and regulatory challenges. It is not simple, and some will undoubtably have a different opinion. I hope it helps address the very understandable knee jerk responses though.

I also have personal views on 999 service moving to the 21st century, but this blog covers just power for 999 calls.

A bit of history

Telephones have been around well over 100 years now. Surprisingly the basic working of the old fashioned analogue phone still works today, but that is changing.

They way an analogue phone works happens to need a small amount of power. There needs to be a voltage (no power really) to detect you lift the receiver. There needs to be enough power to allow the microphone and earpiece to work. There needs to be a bit more power to make a bell ring. This was done using batteries at the telephone exchange.

This meant a telephone would work without the home having power. Indeed, mains power was less common and less reliable over a century ago when phones started. It is also worth remembering that consumer electronics did not exist either - these days we see DC USB power on wall sockets and are used to a small switch mode power supply working some electronic gadget - the idea of a telephone handset being powered from you home is not daft. But a century ago the very power supply itself would be complicated, to say the least, and the phone handset had no electronics anyway - it would not make any sense for a telephone handset to be power from your home mains electricity. So they were line powered, simple as that.

The telephone handset was also part of the service, even wired in, for a very long time.

Catch up to today

Today, analogue telephone lines do the same. Yes we have DTMF now, and the handset itself has electronics that do that, but a simple handset is powered by the line still. Of course we have also moved to the telephone being the customer's responsibility and not part of the service itself, something you can choose, and plug in.

It is an issue for the telcos as the electronics in a handset could expect more power than the original telephone lines were every designed to deliver and there are current limits defined as a result.

But also we have a lot more complex telephones now, even simple cordless phones, DECT base stations. phone with answering machine, PABX, and so on. These work using local mains power, and in some cases DO NOT work when no local mains power. In a lot of cases there are special work arounds - a phone system in an office will typically have at least one old school phone, and maybe a relay that switches that directly to the line when power fails. But not all consumer equipment has any means to work in a power failure.

But also, mains power is way more reliable in almost all places.

However, if you have a simple old school telephone handset somewhere in the house, you can still use it during a power cut - yay!

20th Century

For a long time it was expected that ISDN was the future. Indeed, in some countries it really did take off, and a basic ISDN2 telephone could plug in to a socket and work. My understanding is that ISDN2 was design to power a basic ISDN telephone.

I am not sure if BT did power ISDN2 sockets - I have a feeling they did not. They did a consumer ISDN2 (Home Highway) which did have an analogue phone fallback, which was good. But for anyone using ISDN2, an actual ISDN2 handset was unheard of - people used and ISDN2 card in a computer (mainly for data) or a small ISDN2 PABX which needed power to work.

ISDN30 is a large scale service, and that definitely did not power a handset. It was often using fibre. It did not have power fail working, even though 999 should work just as much for such cases as a home phone line.

Somehow BT were legally able to provide a proper telephone service on a line in such cases with no power fail backup! (Do correct me if I have that wrong).

21st Century

The problem is that times are changing, the old school telephone service (landlines) are going away. These days telephony is an over the top service, working over IP, VoIP, that is Internet Protocol. This changes things.

So how does this work in a power cut and who is responsible for it?

Broadband/Internet

A broadband/internet service never had any requirement to be 24/7 100% reliable, or to work in a power failure. OFCOM are pushing more and more for this, and even talking of power failure requirements (for at risk customers, at least). This is a change, and has a cost.

The internet itself is a large interconnected network - an ISP cannot guarantee that even Google works 24/7, that is down to Google, and even they had an outage the other day. An ISP cannot guarantee they have connectivity to some VoIP telephone service provider 100% of the time, as a lot of that connectivity is outside the ISPs control, as is the operation of the VoIP provider themselves. Yes, an ISP may also be a VoIP provider, but there is not reason to make more onerous obligations in such a case, especially as such a company could simply split its operations in two if that was the case, so assume they are separate.

The elephant in the room here is actually where and what a broadband/internet service is - it is provided at the Network Termination Point. For DSL this is the master socket. It is a clear demarkation for where service is provider.

If OFCOM insist that an ISP has to have a broadband service that works during a power failure (even if only for an hour), that is the point at which it has to work. That is no different to the landline provider providing service at the master socket.

The problem is, unlike a landline, having a service working at a master socket is not a lot of help to a consumer in a power cut. Unlike a landline telephone service, broadband service never provided power (for a router). It provides connectivity - the ability to DSL sync on the line using a modem. You need a modem, and that needs power.

Interestingly, BT are talking of battery backup for optical network termination points (ONTs), where the network termination point is an Ethernet socket. That could be useful to a customer if they have a laptop with an Ethernet port and a PPPoE stack. That would allow them internet access in a power cut. But that is an edge case. In almost all cases the consumer has a modem/router/switch/access point, and they have to power that to make it work. Just as they would have to power a DECT base station if they had one plugged in to a landline master socket.

From a regulatory point of view the whole concept of a network termination point is important, it defines where the service is provide and who is responsible each side. The ISP is simply not responsible for what is plugged in.

From a technical point of view the ISP could not sensibly power arbitrary customer equipment. Here, for my laptop to work, I have a router, and modem, and large PoE switch, and 6 access points. Powering all of those for an hour is a big undersaking, but not doing that means I don't have internet at all. I don't have a system to fall back to just a modem and one access point, but powering even one AP is a lot.

Should companies making and selling network routers, switches, and access points, have to ensure battery back up, just because they could be used to carry VoIP traffic for a 999 calls?

So yes, I suspect a service still working at the network termination point, and hence powered ONT, might happen. It happens for DSL lines, we think (BT have batteries in street cabinets, but not sure if all, or for how long). But it will be not help for 999 calls.

VoIP provider

The other side of the coin is a telephone service provider using VoIP.

The very nature of the service is that it is oIP, i.e. over IP. It depends on working internet access.

Does it make sense to expect the VoIP provider to somehow make it work when no internet access, well no, it does not.

Does it make sense for the VoIP provider to provide battery backup? Well, for what? If the provider rented a SIP handset, maybe they could power that for you, but that does not help in a power cut if nobody is powering your modem, router, and network switch, all of which are very much out of the scope of the VoIP provider. And if they are not renting a SIP handset, or providing as part of the service, even that handset is out of scope.

I VoIP provider should ensure their equipment has power backup and redundancy to allow 999 calls, but that is actually pretty easy in a data centre. Data centres have lots of power backup and redundancies.

The key issue here is that making the broadband work at home is down to a lot of equipment for which the consumer is totally responsible, and not the broadband provider, and not the VoIP provider.

Should companies making/selling SIP handset have to ensure battery backup? And would it help? Maybe if modem and switch manufactures had to do the same. But none of that sounds sensible.

Landline replacement

There is a middle ground here, a landline replacement service. This is something we see, and likely to be something BT has to do as the incumbent operator with a Universal Service Obligation.

Being a replacement it IS REASONABLE for the customer to expect it to work like the service it replaces. This means a provide providing not just internet access to a network termination point, but modem and router with an old school analogue telephone socket. The termination point for that overall service is the analogue phone socket on the router, and so it is reasonable to expect that to work in a power cut, with an old school analogue phone. So likely that will have battery backup as an option.

So, at least for now, due to jet more legacy it is likely BT will still provide this, at least for at risk customers.

Should someone else do this anyway

The big issue at hand is power cut. Would it not simply be sensible to regulate that power companies have to do something.

They already have a priority service register and already roll out generators to vulnerable users (e.g. those with powered medical equipment at home). I'm on the register as I have insulin in the fridge, which was one of the criteria - I also (now) have Tesla batteries so won't need a generator for even a very long power cut.

Having to provide a small USP enough to cover a broadband modem, and router, and SIP ATA to work a handset, is not a big step, and not a huge cost if only for at risk customers.

It makes a lot more sense that insisting telcos provide power. Just like it makes sense that power companies are not expected to provide telephony.

Maybe this is the real way forward here?

17 comments:

  1. We have customers who take their phones (sometimes physical devices, but mainly softphones) all over the country who have, on occasion, needed to make 999 calls. Then they have had to explain to the operator that they're actually on the North coast of Scotland and not in their office in Penzance, for example. I understand that they have had to be transferred to other response centres because of this.
    Speaking to various suppliers and providers, the unofficial official (!) advice is "If you want to make a 999 call, use your mobile".
    But this in itself has problems - what if you're in a not-spot or ... what if there's a power cut and the mobile network has gone down?
    From experience, there's one mast that covers our house. When we have a power cut, so does that mast. When there's a power cut, we have absolutely no way of making a 999 call.
    So with the death of landlines and the rise of the mobile, perhaps Ofcom should move the USO to mobile networks - ensure 100% (or as near as practical) coverage for 999 calls and install UPSs and generators at all appropriate masts!

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  2. Worth checking that the Tesla power bank works in a power cut. As in understand it, most as standard only work when there is a grid connection for safety reasons (avoids back feeding an otherwise dead line). I think it'd need a changeover switch to isolate it from the mains in a power cut

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    1. It takes a few seconds to change over, but yes, all works in power cut. When electric meters was changed recently I was able to switch over house seamlessly, which impressed the guy changing the meter!

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  3. Where a customer has a wired Internet connection, the service provider should be required to offer a reliable but limited service in a power cut. It could be limited to a single, special port on their termination point, should be optional, and could be at an extra charge.

    Urban users wouldn't bother. They have mobile service, neighbours, internet cafes, nearby emergency services and nearby businesses. But for rural users it might be critical, and worth paying for.

    I would probably say the service it provides should be separate from the normal service: very limited, probably using an IP address separate from the normal service, restricted to providing VoIP and some low speed web browsing (for example to look up your electricity company's fault reporting number). But defining that would be up to a standardisation group.

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    Replies
    1. What I am saying is that they do, at least on DSL. They offer working ADSL or VDSL on the master socket in a power cut. Normal service. You just need (a suitably powered) set of customer equipment to use that service at the termination point.

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    2. Why should rural users pay more? They already have higher transport costs (no public transport), higher fuel costs (not connected to gas mains), lower connection speeds (no Virgin/CityFibre/FTTP/whatever) and longer response times from the emergency services (further from hospitals/police stations/fire stations) - why punish them for this as well as their not having a mobile service, neighbours internet cafes and nearby businesses?

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    3. I don't think anyone is "punishing" anyone.
      Also, rural areas often involve more costs supplying a service.
      Should everyone else pay to subsidise those that choose to live in a rural area (playing devil's advocate there).
      But for VoIP, and 999 access, I don't see why rural areas should cost more - it works over DSL in rural area, so what are you suggesting will cost more in a rural area?

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    4. "working ADSL or VDSL on the master socket" is not enough. They should also be required to provide power (how much? for how long? etc - that needs more work) and equipment that can use it (what equipment? who pays? - again, that needs more work). The point is that the user should be able to stay in contact with family, friends, health services and emergency services.
      I have in mind my 90yo mother-in-law. She has always been able to lift the receiver and dial us, or dial 999, even in a power cut. That (plus, in the modern world, email and simple web browsing) is the **service** that needs to be provided, for as long as the power cut lasts.
      Don't start with thinking about the technology - start with thinking about the service that needs to be available.

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    5. But broadband/internet is not “telephone” service so nothing to do with calling 999. And broadband, unlike telephone, has never been expected to power customer equipment. And if it did provide as much power as a phone line used to, that would not run a router (just as it would not run a DECT base station).

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  4. The first DSL modem I had was usb powered and, I guess, could have worked from a battery powered laptop. Not exactly convenient for calling though. I'm not sure you can get such a thing any more anyway.

    The problem with a UPS is, how do you decide how long it should last?
    Although if course, the batteries at the CO would also run out eventually in a power cut.

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    Replies
    1. Exactly, so working DSL at master socket is viable *if* you have the right CPE, no different to old school telephone which only worked with the right CPE.

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    2. Remember UPS batteries need maintenance - even on float, they don't last forever. A one-time activation power supply for emergency use - which the user was then responsible for replacing, perhaps based on dry cells, might be one answer?

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  5. Whilst the venerable RevK started this post about power issues, this isn't the only problem. Our non-AAISP uses BT Wholesale for backhaul and there was a hardware upgrade this morning at 4am - unfortunately the hardware failed at 6am and replacements aren't due on site until 8am and working until 11am. That's nearly 5 hours we are expected to be without usable internet (mobile access is extremely unreliable jere) and so would have no telephone access to emergency services even if we did have backup power.

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    1. Faults have always happened, what is different is a broadband fault is something you spot immediately. A telephone fault you may never know of, especially if over night. This is not new. However, broadband provision is not 999 provision and so does not have the same (legacy) 24/7 obligations as telephone (for 999).

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  6. I don't suppose anyone will care, but my recollection is that Home Highway could power an ISDN2 phone direct, I certainly owned an ISDN2 phone which worked without an additional power supply and without a PBX, connected direct to the HH wall box. I can't remember if the HH wall box itself needed mains power or not though - I *think* not, but I can't be 100% on that. Patrick

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    Replies
    1. I know the ISDN lines themselves carried 90 volts or so, and I'm pretty sure my own HH box had no mains adaptor because it was in a room with no mains sockets (in an old hallway)
      Gord

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  7. All the original telephone exchanges back in the early days of the telephone were 'local battery' exchanges where the line was powered by batteries at the customer. Graham.

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