Max Stevens CSL Group - Head of Telecare IoT
2 min read

The recent announcement by Openreach, a part of the BT Group, to extend the final switch-off of the Public Switched Telephone Network (PSTN) to January 31, 2027, has significant implications for various critical service sectors and devices like emergency phone lines, security alarms, and lift alarms. This additional 13-month extension from the original deadline of December 31, 2025, is a strategic move to ensure services used by vulnerable individuals undergo rigorous testing before migration. However, despite the extension, the urgency for migrating PSTN-dependent systems remains critical.

The importance of maintaining momentum

Despite the extended deadline, it's crucial to maintain the momentum of the migration efforts. The additional time should not be perceived as a pause but rather as a strategic extension to ensure the migration process is thorough and minimally disruptive. Here are the key points to consider:

Proactive Planning: The extension provides a realistic framework for completing the migration tasks, reflecting the complexities involved in such a vast national transition. However, it is essential to use this time wisely for planning and implementing necessary upgrades.

Continued Efforts: Momentum for non-vulnerable connections will continue, with the aim of completing an additional 7 million line upgrades to match the 7 million already completed.

Avoiding Future Disruptions: Industry experts emphasize that proactive planning and timely upgrades are essential to prevent future disruptions, ensuring that all critical services continue to operate smoothly.

Addressing concerns in the Telecare sector

The delay in the PSTN switch-off primarily addresses concerns centred around telecare products used by vulnerable individuals. Telecare systems, which include emergency alarms and health monitoring devices, are crucial for the safety and well-being of approximately 1.8 million vulnerable people in the UK. Recent incidents have underscored the importance of a seamless transition:

There have been cases where the failure of telecare devices following the switch-off of analogue phone lines has had severe consequences, including the deaths of two vulnerable individuals. Although these incidents have not been formally linked to the non-functioning devices, they have highlighted the critical nature of this transition.

The extension allows for more rigorous testing procedures to ensure that all critical systems are fully functional and reliable post-migration. This is crucial to prevent any disruptions in emergency services that vulnerable individuals depend on.

Recent incidents have underscored the critical nature of the PSTN to digital transition, particularly in the telecare sector, where ensuring the reliability of emergency alarms is paramount. The extension aims to address the following key issues:

First-time call failures due to analogue and digital compatibility issues

One of the major challenges during this transition is the compatibility between analogue telecare devices and the new digital networks. Analogue devices are designed to send data over the PSTN, and they often face issues when interfacing with digital networks. Here’s a breakdown of the problems and their implications:

Data transmission issues

Analogue telecare devices send data formatted for the analogue telephone network as tones. When this data is converted for transmission over a digital network, the timing between tones can be altered. This error, also known as round trip delay, causes significant communication problems.

Handshae failure

The altered timing can lead to handshake failure, where the monitoring centre (Alarm Receiving Centre or ARC) fails to recognise the alarm call and rejects it.

Repeated call attempts

The telecare device will then repeatedly attempt to resend the alarm call, resulting in lengthy connection times. This issue, known as first-time call failure, can escalate to total call failure if the call continues to be rejected.

From the perspective of the person making the telecare alarm call, it appears as though it takes an unusually long time to connect to an operator. Unfortunately, operators at the monitoring centre cannot see these failed call attempts, compounding the problem.

Estimates suggest that first-time call failures, where a telecare system cannot communicate correctly over the newer digital network, are as high as 30%. This high failure rate highlights the critical need for thorough testing and seamless integration of telecare systems with the digital network to ensure that vulnerable individuals receive timely and reliable emergency assistance.

Impact on other critical services: Security, Fire, and Lift Alarms

While the telecare sector has been a key talking point, other critical services such as security systems, fire alarms, and lift alarms are also significantly impacted by the PSTN switch-off:

Security Systems

Many security systems rely on PSTN for communication. The transition to digital is crucial to ensure continued functionality and enhanced features such as clearer call quality and modern capabilities like placing incoming calls in a queue.

Fire Alarms

Fire alarm systems that rely on PSTN need to be upgraded to digital to ensure they can continue to provide early warnings and ensure the safety of buildings and their occupants.

Lift Alarms

Lift alarms, essential for the safety of individuals in case of elevator malfunctions, must also be upgraded to ensure they can reliably communicate emergency situations post-PSTN switch-off.

As the PSTN switch-off deadline approached, many businesses expressed concerns about the programme. Research indicates that 54% of businesses feel the switch-off has not been well-publicised, highlighting the need for continued education and support to ensure all sectors are adequately prepared. Initiatives like "Fit to Switch" aim to educate end-users and businesses across various sectors about the potential risks and the importance of being prepared for the switch-off.

The extension of the PSTN switch-off deadline to January 31, 2027, provides a valuable opportunity for all stakeholders in critical services sectors to thoroughly prepare for the transition. However, it is vital to maintain the momentum and continue proactive planning and upgrades. By doing so, we can ensure that telecare systems, security systems, fire alarms, and lift alarms are fully functional and reliable post-migration, safeguarding the well-being of vulnerable individuals and the general public.

For more information, and to ensure your systems are fit to switch, download our FREE guide to Voice communications for critical solutions in a post-PSTN world. Our experts in Critical Connectivity and solutions are here to help you navigate this transition seamlessly and ensure continued operational excellence.

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