4G VoLTE landline replacement communicator

With the Public Switch Telephone Network (PSTN) switch-off scheduled for 31 January 2027, lift owners and facilities managers need a reliable path to digital communications. ControlFreq’s 4G landline replacement ensures existing analogue devices — including lift emergency phones and critical voice systems — remain fully operational. It provides a secure, compliant, and future-proof solution for uninterrupted connectivity.

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What is Landline Replacement

ControlFreq’s 4G landline replacement converts analogue PSTN calls to 4G VoLTE, keeping legacy systems connected as the PSTN is phased out and avoiding costly equipment replacements. A built-in battery backup keeps lift phones and emergency lines operational during power outages, while VoLTE’s HD audio ensures crystal-clear communication when it matters most.

Addressing critical connectivity with ControlFreq

Lift alarms

Over 300,000 lifts in the UK rely on PSTN-connected emergency phones, all of which face compliance and safety risks when the network is switched off. ControlFreq provides a simple, low-disruption upgrade that can be installed during routine maintenance visits. The solution ensures lift alarms remain connected, reliable, and fully compliant with the latest safety standards.

Emergency lines

From motorway SOS points to petrol forecourts and national grid sites, emergency lines play a vital role in public safety and demand continuous uptime. ControlFreq’s 4G landline replacement keeps these systems live through the PSTN transition, delivering secure, resilient connectivity that meets the highest compliance requirements.

Real-time visibility with WebAlarm™

ControlFreq devices connect real-time data & analytics to WebAlarm™, giving on-site maintenance, lift engineers and building management teams complete visibility of lift status, power and connectivity, across their entire portfolio. Real-time voice, SMS, push or email notifications speed up resolution and cloud dashboards simplify compliance. ControlFreq offer 7-day technical support to ensure remote assistance is always available when it really counts.

ControlFreq digital communicator

Delivers resilient, high-quality voice connectivity over 4G VoLTE, keeping critical systems online and operational at all times.

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Instant PSTN Replacement

Works with any standard landline device.

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Reliable 4G Connectivity

Eliminates reliance on fixed-line networks.

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Crystal-Clear Voice Calls

VoLTE support for HD audio.

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Critical System Ready

Ideal for lifts, intercoms, and emergency phones.

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Quick & Easy Setup

Plug-and-play installation, no configuration required.

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Optional IoT SIM

Multi-network SIM ensures uninterrupted service.

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Resilience

Equipped with a ControlFreq roaming SIM, supporting 2G, 3G and 4G with automatic failover to keep services connected if one network fails.

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4G VoLTE

Converts analogue PSTN calls from devices like autodiallers and PBX systems into 4G VoLTE, delivering HD voice and reliable data transfer.

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Battery Backup

Provides up to 8 hours standby or 2 hours of talk time during power cuts, ensuring critical services remain online when needed most.

The Landline Replacement 4G-VoLTE digital audio communicator

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Installed in a lift motor control room
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Installed in a control cabinet in an MRL environment
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Our LANDLINE-4G digital audio communicator replaces a BT landline for monitored communications

Upgrade any new or existing lift phone auto-dialler with a universally-compatible 4G-VoLTE voice call communicator. LANDLINE-4G provides a seamless replacement for traditional BT phone lines in emergency lift phone installations without the need to replace the existing auto-dialler. Paired with WebAlarm cloud monitoring ensures full compliance with current lift safety standards BS EN81-28:2022.

Multi-network roaming with built-in redundancy

Feature Details
Instant PSTN Replacement Works with any standard landline device, making upgrades seamless.
Reliable 4G Connectivity Eliminates reliance on fixed-line networks with resilient 4G LTE.
Crystal-Clear Voice Calls Delivers HD audio with VoLTE support for clear and reliable communication.
Critical System Ready Optimised for lifts, intercoms, emergency phones and safety-critical systems.
Quick & Easy Setup Plug-and-play installation with no additional configuration required.
Optional IoT SIM Multi-network SIM ensures uninterrupted service with automatic failover.
Battery Backup Up to 8 hours standby or 2 hours talk-time, BS EN81-28 compliant.
Housing Industrial-grade enclosure for reliability in mission-critical environments.
Remote Management Optional WebAlarm integration for monitoring network and power status online.
Event Log Tracking Access call history, test logs, and alerts remotely for compliance and reporting.
Multi-Site Management Manage multiple devices easily from one centralised platform.

Prepare for the PSTN Switch-Off with ControlFreq

With the PSTN switch-off fast approaching, critical systems need a reliable path to digital communications to remain operational and compliant. Whether you manage lifts, security, or essential infrastructure, ControlFreq provides the expertise and solutions to ensure a smooth transition, safeguard compliance, and future-proof your communications.

WebAlarm™ is our proprietary ‘OEM white-label’ cloud-based platform that adds real-time monitoring, communication and global visibility to your lift phone systems with virtually no effort whatsoever. It provides monitored battery back up to ensure lift safety compliance and provides realtime insight into an estate of any size.

WebAlarm™ | Real-time cloud monitoring, communication & control for lift phones

Emergency Lift phones
Mains power
Battery back up
Mobile network connectivity
Lift faults
Event logging
BS EN81-28:2022 compliance

Instant alerts

Receive immediate notifications via voice call, email, SMS, or push alerts whenever an issue occurs, ensuring rapid response maintenance teams before critical failures escalate for maximised operational continuity.

Real-time visbility

Monitor your lifts effortlessly with a real-time overview from a central online dashboard. Gain full visibility and control to maintain operational reliability, optimise performance and compliance at all times.

Upgrade your lifts to digital communications – speak to an expert today.

Send us a message to arrange a call with a digital communications speacialist and take the hassle out of upgrading your estate with our full solution and support.

Frequently asked questions

  • The Public Switched Telephone Network (PSTN) is being phased out in the UK. Older lift emergency phones that rely on analogue PSTN lines will stop functioning. To avoid service interruption, these systems must be upgraded to a digital alternative, such as GSM ie: ControlFreq LANDLINE-4G or IP-based communication. Non-compliant lift phone systems may result in the lift being taken out of service.

  • To comply with EN81-28:2022, an emergency lift communication system must include:

    • Two-way voice communication between the lift car and a rescue service.

    • Remote dial-in communication for the monitoring service to dial back into the lift if cut off

    • Physical testing of the lift alarm every 3 days, using a method equivalent to a user raising a genuine emergency call alarm

    • Monitored battery backup for both the autodialler and, if used, the GSM gateway with 1 hour standby and 15 mins talk time.

    • Automated alarm transmission with confirmation from the rescue service, with no user input required once an alarm is triggered.

    • Automatic identification of the lift’s location and ID to the rescue service.

    • Visual and audible indicators inside the lift car, including green and yellow pictograms and an adjustable tone to indicate call progress and status.

  • Upgrading to a ControlFreq LANDLINE-4G ensures compliance with the BS EN81-28:2022 standard. Upgrading to a GSM gateway that does not meet the standard would not the issue of PSTN shutdown. The upgraded system must also meet the standard’s requirements for monitored battery backup, 15-min talk time on battery, self-testing, alarm verification, and passenger indicators. A GSM upgrade must be part of a wider compliance strategy.

  • Yes. The LANDLINE-4G meets and exceeds the requirments with 8 hours standby and 1 hour talk time on battery back up. All other GSM gateway requirements are also met or exceeded.

  • The building or lift owner is ultimately responsible for ensuring that lift communication systems are compliant with BS EN81-28:2022. LANDLINE-4G ensures saftey compliance by meeting all the requirements of the standard. Installation is a simple plug&play process without the need to replace existing lift auto-dialler hardware. By fitting the LANDLINE-4G, compliance is met. Simply power the device locally to the lift auto-dialler and connect the BT connection to the LANDLINE-4G. Job done!

  • Since February 2025 the lift alarm safety standard BS EN81-28:2022, states the system must be tested every 3 days using the same method as. areal alarm call to simulate a real world scenario.

  • Yes. We offer digital upgrades which replace legacy PSTN lines that allows you to leave existing lift phone equipment in place and simply upgrade the communication path from analogue to digital. We offer a managed service including an initial consultation, detailed proposal, pilot trial and measured results prior to a controlled phased rollout.

  • Yes. Pilot trials are offered to prove functionality and suitability for the application before committing to a phased rollout.