On 7 November, Jim had the opportunity to host a GSMA Webinar on SMS for IoT after 2G/3G shutdown, with guests from Deutsche Telekom (Ronan Lacroix) and KDDI (Keita Kowaguchi).
As global mobile networks accelerate the shutdown of 2G and 3G technologies, the implications extend far beyond legacy voice and data services. One critical area affected is the Short Message Service (SMS) that underpins a wide range of Internet of Things (IoT) applications. The webinar (and associated white paper: Ensuring SMS Continuity for IoT After 2G/3G Shutdown) underlined the importance of preserving SMS functionality over LTE networks and beyond to ensure continuity for millions of connected devices worldwide and described how this can be achieved.
The following paragraphs provide a more detailed summary of the topics covered in the webinar.
Despite its age, SMS remains a cornerstone of cellular network support for machine-to-machine (or IoT) connections. It is primarily used in two ways: as a “shoulder-tap” mechanism that triggers actions in remote devices, and as an over-the-air (OTA) channel for updating SIM or eUICC profiles. From connected cars and smart meters to remote SIM management systems, IoT solution functions can rely on SMS to maintain seamless and secure communication between devices, network operators and end-users.
In automotive applications, for example, SMS is often used to trigger essential functions such as remote locking, remote climate control, and over-the-air software updates. Many vehicles currently in operation depend on SMS over 2G or 3G connectivity and given the average lifespan of cars, often exceeding a decade, these vehicles will remain active long after those networks are decommissioned and with them 2G/3G native support for SMS. Similarly, millions of smart meters in Europe still depend on SMS for control and data reporting, making SMS continuity vital for national energy infrastructure.
The shutdown of 2G and 3G networks threatens to disrupt established SMS-enabled communication channels since many IoT devices cannot use IP-based alternatives to SMS due to hardware limitations. Without SMS, connected vehicles could lose access to remote control services, potentially compromising safety and likely significantly impacting customer satisfaction. In a utilities context, energy operators could lose the ability to collect smart meter readings, leading to inefficiencies in energy distribution. Additionally, the inability to deliver OTA SIM updates could prevent operators from managing network access, roaming profiles, and security settings across millions of deployed devices.
For industries like automotive and utilities, and beyond, replacing or retrofitting existing IoT modules to support new protocols is often prohibitively expensive, with costs estimated to be in the region of EUR800-1,000 per vehicle in the case of automotive vehicle head end connectivity. It is clear that without coordinated action between operators, manufacturers, and roaming partners, service interruptions could affect tens of millions of connected devices globally.
During the webinar, three primary technical mechanisms were discussed for maintaining SMS services on LTE networks:
The GSMA identifies SMS over Diameter as the most future-proof and cost-effective solution for ensuring SMS service continuity across LTE and 5G networks, with SMS over SGs as an appropriate interim solution.
Mobile operators planning 2G/3G shutdowns were urged to take proactive measures to preserve SMS functionality for IoT devices, including:
By following these guidelines, operators can minimise operational risks, ensure global interoperability, and safeguard critical IoT functions through the LTE transition and into the 5G era.
