Speaker: Matt Davies, Head of Strategic Marketing at AVIRE

[00:00:00] Hello, my name is Matt Davies and, in this webinar, we will be looking at the impact that the digital switch of the UK telephone network is having on lift emergency alarms. We’ll also be looking at solutions that you can put in place to ensure that lift emergency communication remains operational and in compliance with the latest standards.

We’ll start off with a quick summary of the key takeaways. Firstly, analogue telephone lines are being removed now and the pace of that change will only accelerate over the course of the rest of 2021 and into 2022. By the end of December 2025, all analogue support will have been removed from the UK telephone network.

The main impact we’re going to see is that power backup options for landlines will no longer be good enough for emergency communication. In which case, existing analogue emergency telephone installations should be switched across the GSM to ensure that they remain [00:01:00] operational and compliant. We would also suggest that you consider a full replacement with a digital system.

The agenda that we’ll follow today is:

  • What is the digital switch and how will it impact lifts?
  • Commonly used terms that will occur throughout the presentation.
  • The public switch telephone network (PSTN), also known as the landline network in the UK, and a little bit of background as to how that operates today.
  • The effect that BT Openreach’s fibre first campaign will have.
  • Lastly, we will review the impact on various different installations and the solutions that you can put in place.


So what is the digital switch? The digital switch is the deployment of fibre optic cables to replace the existing copper cabling in the network. Today that copper infrastructure supports some key analogue signalling technologies. [00:02:00] First of all, there’s a dial tone on the line. This is how units check that the line is operational before placing a call. Telephone lines also supply 48 volts of what we call line voltage. Some equipment which is currently installed in the UK uses that line voltage to power the emergency telephone itself. Lastly, you have dual-tone, multi-frequency signalling, or DTMF. You would probably know this as touch-tone, and it’s the tones that are generated when you press the various keys on the telephone keypad. DTMF is also used for a lot of legacy machine to machine communication (M2M), which takes place over the landline network.

The reason fibre is being deployed in place of copper is due to our ever-growing demand for data services. Copper is a poor medium for carrying data whereas fibre optic allows much greater speeds. This is being done both for domestic demand and commercial demand [00:03:00] as we see a change in the telephone network from voice being the most important layer to data being the most important layer. There is also another thing that is worth mentioning in that some areas are no longer able to physically deploy copper cables due to a lack of actual space in the ductwork.

What’s the impact on lift emergency telephones? First of all, as we transition from copper to fibre there’s the loss of the dial tone, lots of dial tones on the line will be interpreted by many units as if the telephone line is failing. This may well lead to them not dialling out in the event of the alarm button being pressed.

Next are the three-day test calls that emergency telephones are obliged to place under the EN81-28 standard. This is a standard call that they make every three days and is essentially a proof of life that the telephone is in place and working correctly. All of that information exchanged during that three-day test call is done through DTMF tones. [00:04:00] The loss of DTMF on the fibre network means that those calls will not be able to be placed so you will not have a compliance record of your telephone being in service.

We also have what we call operator commands. These are various commands that an emergency operator can use while they’re talking to a trapped passenger through a lift emergency telephone. This includes:

  • the ability to playback the location message of the lift if the trapped passenger isn’t able to identify exactly where the lift is
  • the end of the alarm signal, which is a signal that’s required to be sent to remove the emergency telephone from an alarm state after a trapping incident
  • and also, the ability to mute the speaker or microphone during the call. That’s quite important if you’re dealing with a trapped passenger who is panicking, and you need to control the flow of voice communication.

Again, the loss of DTMF means that in older equipment those commands will no longer be possible.

Also, fibre cannot carry the line voltage that copper [00:05:00] had, and line voltage will be removed from the existing copper. That means that what we would call a line-powered emergency telephone (a telephone which draws its voltage from the line) will stop working and there’ll be a requirement to put in an additional power supply and backup solution (probably a battery) to keep these working. The main point here is that the event in the event of a mains power failure, telephone lines will now fail.

Based on all of this, our estimate, working with the Lift and Escalator Industry Association (LEIA) in the UK is that there are around 180,000 lifts out of the roughly 300,000 installed in the UK, which will require some form of intervention for the emergency communication to continue to function correctly.

Very quickly, some commonly used terms that you’ll hear throughout the presentation (and in fact, I’ve already used some of these):

  • Analogue signals. This is a signal whereby the behaviour is in the form [00:06:00] of a wave with respect to the amplitude of the wave, the time period or the phase signal. In the context of what we will be talking about today, analogue signalling primarily signals which are sent over the voice channel on the telephone line. It’s things like the DTMF tones we mentioned, which leads me nicely onto…
  • DTMF (dual tone, multi frequency signalling). This is a technology introduced in the 1960s and it refers to the audio tones, between the equipment and other devices to transfer information. The easiest example of this is when you dial a telephone number on a handset, the sequence of keys you are pressing generates a sequence of tones and that is how the switching centres know how to direct your call.
  • Digital signals. We move away from the wave and amplitude world into the world of the bit rate. What we have here is a digital signal, a series of ones and zeros, and this has [00:07:00] some inherent strengths against analogue signals and it’s a big part of why this is being moved across.
  • This is the public switch telephone network. It’s the domestic telephone communications network in a given country. If I say PSTN think landline because that’s what we’re talking about.
  • We’re talking about optical fibre or rather fibre optic to use the more common term. This is a flexible, transparent fibre, which is either made from drawing glass or plastic. Typically, the diameter is slightly thicker than human hair. It is used instead of metal wires because signals can travel a lot further without any loss. Additionally, fibre is less immune to electromagnetic interference, which is a common problem with signals being carried over metal wires.

Just a little bit more on dual-tone, multi-frequency, because there is a complexity here that we need to highlight. We would typically understand there to be 12 tones on a telephone [00:08:00] keypad, 0-9 plus *, and #. In the context of the presentation today, we’re talking about DTMF as it’s used for machine to machine (M2M) communication. For M2M, there are an additional four tones, which are ABCD. We don’t see those on a traditional keypad because traditional keypads aren’t used for this type of information transfer. A point to note with DTMF: any interference with the tone (so that can be the frequency being changed or the sequences of the tones being out of order) will render any data that you’re trying to transfer unreadable. This is a system which is inherently very susceptible to any kind of interference.

PSTN also known as landlines. The network in the UK, like all others, was originally built on copper and analogue technology. This means you have the dial tone and you have the 48 volts supplied on the line. [00:09:00]

Touch-tone technology was invented in the 1960s and introduced in the 1970s. Digitalisation of the network really begins in the 1980s, but most of that work is at the exchange level where older analogue equipment in exchanges was being removed and replaced with digital microprocessor driven equipment. The switch from copper fibres to fibre optic cables really begins in the 1990s with the growth of the internet and the demand for data services on the network. Now that very brief history I’ve given you there hasn’t really affected the lift industry because analogue support has always been maintained. And that’s going to be the BIG change we’re going to see, the removal of that analogue support.

Also, to bear in mind, EN81 28, which is the European standard covering lift emergency telephones, was only introduced in 2003. At the time that was introduced, all the major changes on the network had already happened. However, what we are now entering is a period of sustained and [00:10:00] major change.

We’ll talk about a couple of terms here, which are going to become important later.

Fibre To The Cabinet (FTTC). You can see on the right-hand side of your screen a picture of a typical telephone cabinet in the UK. You will see these at the end of the streets or at the entrance to industrial estates and so on. And what you’ve got there is a telephone line coming from the exchange meeting this cabinet and then being distributed out as separate lines to individual premises. Fibre is run from the exchange to the cabinet and 96% of the UK network 10 years ago was already working like that. But the last mile (as it’s called – from the cabinet to a given building) is copper. The copper carries the low voltage we said and there’ll be a dial tone and so on.

What we are now moving to is Fibre To The Premises (FTTP). This is where we have an end-to-end fibre run from the exchange all the way to the building. Now Openreach has been [00:11:00] deploying that since 2012 in parallel with copper, but this will be the big change that we will see Fibre To The Cabinet will be replaced with fibre straight through to the premises. As we sit today, both currently support a dial tone on the line and DTMF signalling, but that will change.

The digital switch is backed by Openreach’s Fibre First Programme. Openreach is the telephone infrastructure provider in the UK – these are the people who are laying the physical lines and they’ve been deploying fibre for some time.

We begin all the way back in November 2016 at that point 99% of all new construction in the UK, new buildings being built where there were 30 or more units, were built as Fibre To The Premises. That can be 30 individual buildings, or it could be one block of flats with 30 individual flats. [00:12:00] By the beginning of January 2018, there were half a million premises in the UK serviced by Fibre To The Premises. We move on to April of that year and copper lines were no longer automatically installed for any new construction. A new building being built from then on automatically receives Fibre To The Premises.

At the beginning of 2019, Salisbury was announced as the first full-fibre city. Salisbury was the first testbed for a complete fibre network. This is where Openreach tried out a lot of what they’re now deploying across the whole country. By the middle of 2019 Milburn Hall in Suffolk was then added as the second full-fibre city. By the end of December 2019, 2 million premises were now served by Fibre To The Premises. By December 2020, Salisbury entered what’s called stop sell, and we’ll talk about what stops selling means later because it’s very important to this story. [00:13:00]

With stop sell, or copper stop sell as it’s called, we see the removal of analogue support in a given area. When an exchange area reaches 75% as Fibre To The Premises, what’s called a stop sell will be announced. What this means is no new analogue lines or services will be provided in that exchange area: no dial tone, no DTMF and no 48 volts of line voltage.

Any changes to existing analogue lines will see those services restricted. By changing communication provider (your communication provider is who you pay your phone bill to) or if you move from communication provider A to communication provider B, because it’s cheaper or there’s some other reason as you move across, you will lose the analogue support on the line.

There is also a working line takeover. [00:14:00] This is where lines are moving between end customers. When a company vacates the premises and a new company moves in and they take over the lines, then they will again see the loss of the analogue support if that change is made. There’ll be a national stop sell in September 2023, but local stop sells, like the one I mentioned on the previous slide in Salisbury, started in 2020. Exchange areas are given 12 months and then the local stop sell comes into effect and you’ll start to see analogue support going away.

By March 2021, there were four and a half million premises served by FTTP. You can see that’s a massive increase from the 2 million that we saw in 2019. In June of 2021, 117 exchange [00:15:00] areas entered local stop sell. That’s now 1.2 million premises where they were at risk of losing their analogue support based on what I outlined on the previous slide. As I said, by September 2023 we will see the national stop sell. And by December 2025, all analogue support is going to be removed.

A little bit more on Fibre To The Cabinet, just so it’s clear. We have the exchange building to the cabinet, and the green you see is all copper. We have dial tone, we have DTMF signalling and we have the 48 volts of line voltage. There’s a selection of emergency telephones down the side. The Avire Memcom is at the top and then two other units. We introduced Fibre To The Cabinet (that’s the fibre between the exchange and the cabinet) and nothing changes. However, when we enter copper stop sell, we lose our analogue support, [00:16:00] which means all these telephones will potentially be compromised in their operation.

With Fibre To The Premises, as you can see, we have fibre end to end and this includes any new construction which is being built. Here we have no dial tone, no DTMF, and no 48 volts.

Let’s talk about what that actually looks like in a building. Below there you can see the typical master socket, which you’ll receive from Openreach. That’s got at the bottom the connection for an analogue phone and at the top a data connection. That is going to be replaced (it’s already being replaced) by what’s called an optical network termination point or an ONT. This is what ONT’s look like: a much bigger box with a lot more going on. If you look on the right-hand side of the slide you can see that arrow which shows you’ve still got that analogue port there.

Now what’s interesting about these ONTs is they’re not receiving any line voltage because they’re [00:17:00] connected directly to fibre therefore, you’ll see them plugged into a wall socket (you can see the power supply at the top there). As they’re reliant on power from that wall socket, they currently also have a battery fitted. Now the battery status is flagged by these three LEDs, which are on the front of the unit. As you can see, this is actually my ONT in my home and my battery status is good. I don’t have any faults and it’s not charging because I haven’t had a power cut. However, if we do have a power cut, we’re going to see some problems.

Moving forward: battery backups are no longer going to be provided on the ONTs. OFCOM, which is the UK telephone regulator, only requires that vulnerable customers are provided with a battery backup, and even then the battery only needs to support 999 calls. This is a big change from where OFCOM has been in the past, but essentially what OFCOM was saying is they believe that enough people have mobile phones [00:18:00] now, that it’s no longer an essential requirement for your landline to be working in the event of a power failure. Obviously, that gives us a critical problem with lifts because the lift is inherently hostile to mobile phone signals and the Standards require that a separate emergency telephone be in place.

Communication providers may provide an optional battery backup, but of the 650 different communication providers in the UK, we’re not seeing any indication that they’re going to provide these as standard and instead, they’ll be looking at vulnerable customers (people who have a specific reason that they’re unable to use a mobile phone – it can be people with disabilities, elderly people, etc.). It’s been made quite clear they do not judge a lift line to be a vulnerable customer.

Can we rely on a landline in the event of a mains power failure? We don’t believe so. The battery backup will either [00:19:00] not be in place or may be a slightly questionable supply that’s been brought in after the fact.

We saw this change in Australia and Switzerland previously in 2016 and 2017. They underwent very much the same process of moving from fibre to copper and no one was willing to take on the liability of guaranteeing a fibre line in the event of a power failure.

What will the PSTN look like moving forward? Just to clarify, the PSTN infrastructure is provided by Openreach. Communication providers are who your clients will be engaging with. There will be the option for battery backups, but provisioning will vary by communication provider and will in most cases be optional – your client would need to specify to their communication provider that they want a battery backup. Maintenance for that battery backup (ensuring that it’s in place and ensuring that the batteries are working) would sit with the client [00:20:00] as it is the client who is effectively the owner of the telephone.

Then the other thing, we may see are analogue telephone adaptors (ATA). I get a lot of questions about these. These may be provided by some communication providers, but we’ve seen no plans announced. An ATA simulates DTMF tones to an analogue device and then translates those into a digital signal that can then be passed over fibre. We have extensive experience with these when we’ve been dealing with in-building IP phone systems. Our experience has been that they are very difficult to set up and most providers don’t see them as a priority. It does exist as a technology. The issue with these is the type of ATA will vary depending on how the communication provider has implemented the line.

What are the options for existing emergency telephones? Top left of the screen you can see that we have the [00:21:00] master socket with its 48 volts and power plugged into an emergency telephone. That’s going away. What is it going to look like? We’re going to have the optical network termination (ONT) that’s supplied by the mains power, and it will require a battery backup. Let’s say we could then find an analogue telephone adapter, that ATA will also require a backup supply because every piece of this chain needs to work in the event of a power failure for an emergency call to be placed. If the emergency telephone is line powered today you will also need a power supply that’s capable of providing 48 volts which you’ve lost on the line and again, a battery backup to ensure that that telephone can keep working. Now we’ve got a lot of extra parts here and a lot of battery backups, which are going to be difficult to maintain and difficult to understand the status of at any given time.

Something that is important to note when we talk about the [00:22:00] EN81-28, the lift emergency telephone standard is that it clearly places the transmitter outside of its scope. Today, all of the alarm equipment (the emergency telephone itself and any battery backup that’s built into that emergency telephone) is within the scope of the Standard. Everything else is outside. Everything we’ve got in the box there, the ONT, ATA, the battery backups and the mains power), that’s all classed as the transmitter so it’s outside of the scope of the Standard and therefore, outside of the scope of responsibility of the lift maintenance provider.

Our recommendation would be to move to a GSM link, and our suggestion would be the Avire Digital Communication Platform (DCP). The DCP includes a battery backup and runs over the mobile network so we’re no longer reliant on the landline network to work, and in the event [00:23:00] of a mains power failure, the DCP has its own battery backup which is monitored – it can flag to you if it has any problems with that backup.

We then have a SIM card that we can provide, which has some important functions. First of all, it’s a machine to machine (M2M) SIM card so it identifies itself to the mobile network as not being a consumer SIM, therefore there’s no danger of it being deregistered from the network for low usage. It’s also a non-steered roaming SIM card. This means it will connect to any network and it always searches for the strongest signal, so you’re not tied to a single provider and what their signal strength may be on a given day. You’ve got a system here which will always be seeking out the strongest signal.

We also have the ability in the DCP to do what’s called DTMF digital conversion: a telephone that is capable of running the P100 protocol can be switched into the P100 protocol and then the [00:24:00] DCP is able to take the DTMF signal from the emergency telephone, convert that to data and pass that over to the mobile network to the receiver. There is still a risk of interference here because you do still have an analogue line connecting the emergency telephone and the DCP itself.

A fully digital system however, (this would be the Avire DCP and the digital audio unit or DAU) has a number of advantages. Firstly, we’ve removed all of the analogue signal here. All of those issues with signal interference and problems are removed and you now have an end-to-end digital solution. You have a single battery backup in the DCP. The DCP is also able to distribute power to the digital audio unit. The DAU also has its own battery, which is monitored so it can send alerts out if it has a problem. [00:25:00]

A note on VoIP systems. A lot of clients have VoIP systems installed in their buildings. We have VoIP devices on our roadmap, but our concern today is again around power backup. For a VoIP system to function in the event of a power failure, both the server that supports the system and all of the VoIP routers in the call chain between the emergency telephone and the outside world will need to have some form of backup. Typically, the standard backups only provide a few minutes of power to allow the server to safely power down, and then the whole system shuts down.

A lift trapping during a power failure is a very common event. You don’t want the telephone line, the communication connection to the outside world to fail, leaving a trapped passenger without any ability to communicate.

In summary, the lift industry needs to be made aware of this and needs to start to act. Your clients also need [00:26:00] to be aware that things are changing now: analogue lines are being removed and that pace will continue. As we’ve said, the power backup on landlines will really not be good enough for emergency communication. Existing analogue emergency telephone installations should be moving off landlines and over to GSMs, and we would strongly suggest you consider a fully digital replacement.

As I said, my name is Matt Davies, I am the Head of Strategic Marketing at Avire. Should you have any further questions, my contact details are there. Feel free to reach out to me or if you’re an existing customer please feel free to contact your current Avire Sales Manager, they’ll also be happy to help.

There will be more of these webinars coming along. I hope you’ve enjoyed this one today. We would welcome any feedback on this and hopefully, I will see you on the next one. Goodbye.


Resources: Webinar Presentation PDF

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