VoLTE (Voice over LTE) is a powerful alternative to the current 2G/3G voice service, delivering superior voice clarity, faster data speeds, and extended battery life for IoT devices. With the full launch of VoLTE now complete, this means Tele2 IoT can globally support VoLTE on any SIM provided by us.  

With the transition from 2G/3G to 4G/5G networks ongoing, the need to shift your IoT devices to VoLTE (Voice over LTE) is increasingly urgent. Most operators are already in the process of shutting down 3G, with 2G closure not far behind. For Tele2, in Sweden 2G/3G will be fully sunsetted by December 2025, which means it is crucial that you ensure your devices are ready in good time, particularly if you work with mission critical applications that rely on voice, such as telecare.  

So, what is VoLTE? 

VoLTE is an IP-based voice service that gives you the possibility to make voice calls in higher quality with faster set-up times over IP-based networks. We have an IMS (IP Multimedia Subsystem) platform dedicated to IoT that will cater for all the voice services that we need as we move away from 2G/3G and to 4G/5G. VoLTE enables operators to migrate their circuit switched infrastructure (e.g. 2G/3G) to a fully IP-centric network. 

Why is VoLTE important? 

Previously, 2G/3G networks used another technology, called circuit switch, which will not be available following sunsetting. So, customers need to move to VoLTE by the end of 2025, when 2G will be shut down (3G is already ongoing). So, to have the voice service up and running, customers need to move to this new technology as quickly as possible. 

What are the main benefits of VoLTE? 

VoLTE offers higher voice quality and faster data speeds. The quality of VoLTE is a big improvement over 2G/3G voice, and for mission critical applications, there is one very important difference: the network can differentiate VoLTE traffic from normal data and prioritize it in the event of network congestion. This will be crucial in the event of an issue or high usage.  

What are the challenges? 

VoLTE quite straightforward. We are talking about calls, of course, so the devices must support this, so that that might be a struggle to address before December 2025 if you haven’t already started. It is crucial that companies address the switch from 2G/3G (and thus to VoLTE) sooner, rather than later, because VoLTE must be enabled on all devices deployed. This may mean switching out devices that are only enabled for 2G or 3G. 

LTE vs VoLTE – what’s the difference?

The 4G network, known as Long Term evolution (LTE), only supports data transfers, webpages, data downloads, and streaming, etc.

Voice over long-term evolution (VoLTE) is an addition to LTE and gives the possibility to make IP-based phone calls over LTE. With VoLTE, we can now also transfer sound in IP-based data package. This gives us high-quality sound, faster call connections, simultaneous voice and data usage, lower battery consumption to mention some of the benefits.

What to consider when switching from 2G/3G to VoLTE?

The time to start planning for this technology change is now. Most IoT devices deployed earlier don’t support VoLTE, and enabling it is a challenge for many IoT-enabled industries because of the costs associated with migration.

• Audit your existing IoT deployment and assess its compatibility with VoLTE. Your IoT connectivity provider can “see” if your devices use voice or data SMS, but doesn’t have information on whether your hardware supports specific technologies
• Identify what kind of new IoT devices you may need for the future
• Pay attention to the location of devices as the availability of 2G/3G in different regions will change over time. Keep track of the planned sunsetting dates in the countries where you deploy IoT devices, and make sure you address markets with the earliest networks shutdowns first
• Devices with 4G/LTE support may not be able to use VoLTE. 4G/LTE devices must be VoLTE-enabled to use this voice service
• Depending on the service needs, in the worst case, the device will need to be replaced to not experience service gaps.

What if VoLTE is not yet available in my area?

The entire telecom industry is incentivized to roll out VoLTE for roaming, and the roaming footprint is constantly expanding. In the meantime, some network operators implement interim solutions.

For example, in the Tele2 Sweden network, we support Single Radio-Voice Call Continuity (SRVCC) for our SIM-cards. SRVCC is the ability to start a call over VoLTE and if needed could be continued in 2G/3G due to devices moving out of 4G/LTE/VoLTE coverage. This will only be available until end of 2025 due to sunsetting of the 2G/3G networks. SRVCC is not supported in roaming scenarios as it depends on the visited operator’s network which only supports SRVCC on their own SIM-cards.

If you would like to learn more or need assistance in addressing 2G/3G sunsetting, please get in touch.