Voice and SMS Transformation Following 2G/3G Sunset

4G and 5G have enabled CSPs to gain access to new frequency bands and to re-farm the 2G/3G spectrum, allowing it to be used in a more efficient way. This results in more capacity and lower costs for mobile broadband. Energy efficiency and security are also improving as the transition from 2G/3G to 4G/5G is progressing.The transition from 2G/3G networks to 4G/5G is globally progressing with more than 50 percent of all mobile voice subscriptions moved to VoLTE or Voice over New Radio (VoNR) by now according to the latest Ericsson Mobility Report.

Some CSPs have already closed their 2G and/or 3G networks but most of these legacy networks are still in operation. This white paper covers important areas to be considered during the evolution from CS voice networks to VoLTE and VoNR. This includes recommendations on how to prepare in the Circuit Switching (CS) and IP Multimedia Subsystem (IMS) domains to close a 2G and/or 3G network and how to adapt to 2G/3G sunsets in roaming scenarios.