BT's Final 3G Tower Closure: Marking the 3G Conclusion

Key things to know:

• End of an Era: BT's final shutdown of 3G in Belfast marks the conclusion of over two decades of 3G technology, paving the way for more advanced 4G and 5G networks.
• Environmental Benefits: The transition away from 3G has led to significant energy savings, highlighting the move towards more sustainable and efficient technologies.
• Global Movement: The UK's phase-out of 3G is part of a worldwide trend towards discontinuing older technologies in favour of enhancing global connectivity and network reliability.
• Continued 2G Support: Despite the 3G shutdown, 2G networks remain operational to support low-power applications, essential services, and IoT devices.

What started out as the latest offering in high-speed mobile cellular technology has now finally been put to rest by BT in the UK, signifying the end of an era. But as these older services are switched off, hardware systems dependent on such services need to either be shut down, upgraded, or replaced. Why has 3G finally been discontinued, what challenges does this present to hardware, and what solutions are engineers turning towards?

Why has 3G finally been discontinued?

When it was first released to the world, 3G was seen as a revolutionary add-on to the cellular market due to its ability to provide substantial download speeds to devices, empower remote computing and internet-related tasks, and eventually allow for video streaming. Furthermore, as 3G was easily integrated into existing hardware, it didn’t take long for its rollout, and coverage has always been sufficient. 

But, just like with all technology, the times moved on, better concepts were introduced, and the demands from consumers only continued to grow. Thus, it didn’t take long for its successor, 4G, to become the preferred network technology. 

Of course, despite having been released in 1998, it has continued to provide services across the globe for the better part of 20 years. Due to the lower data rates, it is often easier to get a 3G signal over 4G, especially in remote areas, meaning that cell reception is rarely an issue. 

The Environmental and Technological Impact of 3G's Closure

However, now that 5G is being heavily rolled out, cellular network operators are recognising the numerous challenges that 3G faces and are actively shutting it down. In fact, it was only recently that BT shut down their last 3G tower in Belfast, finally putting the 3G network to rest. 

The closure of the 3G network by BT marks a significant shift towards more advanced and energy-efficient technologies. As detailed in BT's announcement, this move is not just about enhancing network performance but also about contributing positively to environmental sustainability. The transition has already resulted in substantial energy savings, equivalent to the power needed to charge nearly one billion smartphones. This strategic shift underscores the importance of adopting newer technologies that are not only more capable but also more environmentally friendly.

While other mobile providers in the UK continue to offer 3G, they are also expected to shut these services down by 2025. By doing so, portions of the radio spectrum can be freed, allowing for more efficient applications to utilise these frequencies. 

Global Transition: Beyond the UK's 3G Shutdown

The phasing out of 3G is a global trend, not just limited to the UK. As BT highlights, this transition is part of a worldwide movement to retire older, less efficient technologies in favour of more advanced 4G and 5G networks. This global shift ensures that users worldwide can enjoy faster speeds, better reliability, and a more secure communication infrastructure. The UK's proactive approach in this transition sets a precedent for other countries to follow, ensuring that the global community moves together towards a more connected and efficient future.

Interestingly, with 3G being phased out, 2G is still in active use due to its ability to act as a low-power network option, meaning that 3G has the disadvantage of being too high power for the data bandwidth offered. Such low-energy networks are also increasingly being supported by smart cities and IoT applications that only need to send bytes of data once every hour or so.

The ongoing support for 2G networks, despite the shutdown of 3G, highlights a strategic approach to network management. As BT's 3G sunset page explains, 2G continues to serve as a reliable low-power option, particularly beneficial for critical applications such as emergency services and IoT devices that require minimal data transmission. This careful consideration ensures that while the industry moves towards more advanced technologies, essential services and low-bandwidth applications remain uninterrupted, demonstrating a balanced approach to technological advancement and service continuity.

What challenges does this shutdown present to hardware?

Shutting down the 3G network makes complete sense when considering that it helps free up radio bands (which themselves are incredibly valuable) and encourages engineers to move to next-generation cellular offerings. However, for designs that are currently in the field, the eventual elimination of 3G presents numerous challenges that may be extremely difficult to address.

The first major challenge is that there will likely be plenty of devices installed across numerous environments that rely on the 3G network. It is also likely that these devices are located in hard-to-reach locations, such as on the sides of buildings, inside loft spaces, or in remote areas. As such, trying to locate these devices so that they can either be upgraded or replaced will incur a large manual labour cost. 

Secondly, it is also likely that there exists systems and equipment essential for safety that are vulnerable to the network switch-off. For example, some hospital systems (such as remote monitors) may have been designed around 3G, which, if disconnected from the network, could result in catastrophe. The same could also apply to critical infrastructure, including power stations, refineries, and other essential systems.

Thirdly, even if devices can be accessed, applying upgrades may simply not be an option. For many low-cost devices installed in remote locations, modular designs are not common, and it is very likely that the radio circuitry used to communicate with cellular networks is soldered directly onto the base board. 

This means that existing designs will likely need to be scrapped entirely and replaced with new electronic systems. Not only does this incur large costs with regard to new designs, prototyping, and manufacturing, but it also adds to the growing e-waste problem that plagues the electronics industry.

What solutions can engineers consider moving forward?

There is no chance that 3G will ever be brought back, and sadly, any existing 3G hardware that is in deployment needs to be recalled. Considering that most of this hardware will have to be scrapped, engineers may be left wondering how they should move forward when creating new cellular-based devices.

Undoubtedly, engineers may be worried about whether cellular providers will decide to drop 4G and 5G when newer versions become available, and this is always possible (albeit more unlikely). However, because of this, it may be sensible for new designs going forward to be more modular, allowing for network connectivity circuits to be removed and replaced.

For example, cellular communication boards built onto M.2 Key cards could be highly beneficial in a design, allowing for in-field upgrades to be made should a network technology no longer be available. This also helps to reduce the hardware cost should devices need to be upgraded, as only the comms board needs to be pulled out and replaced. 

Embracing Modular Design for Future-Proofing

Furthermore, this modular design concept also helps to reduce e-waste by only needing to scrap the comms board. However, engineers who want to avoid a modular design should consider programmable hardware, such as FPGAs. 

While these may not be able to handle various comm frequencies, any hardware that supports reconfiguration out in the field will be far more likely to withstand future changes. For example, software-defined radios can be potentially used with cellular systems, allowing for a device to change the frequency at which it operates. From there, if an FPGA is used to handle digital data streams, it becomes possible to not only adjust the frequency used but the digital decoding of that data.  

Overall, the removal of 3G has been a long time coming, but its removal also introduces questions regarding the reliability of networks and how engineers are always at the whim of service providers. Fundamentally, designs that need to operate for extended periods of time need to seriously consider these factors and be designed to accommodate for future changes.