SK Telecom and Nokia have announced joint development of “Mission-Critical Push-To-Talk (MCPTT) solution, which is a next-generation push-to-talk communications technology over VoLTE, and demonstrated the solution at Nokia's Research and Development Center in Kraków, Poland.

SK Telecom plans to utilize the MCPTT solution for Public Safety-LTE (PS-LTE) and LTE-Railroad (LTE-R) in Korea and also expects to expand its reach to countries that are currently promoting the public safety network projects such as the United States and Great Britain.

As the standard for mission-critical-voice functionality over LTE adopted by the 3GPP standards body, MCPTT enables efficient communication among hundreds of rescue workers by using a dedicated channel at times of massive disasters.

Unlike the existing IP-based push-to-talk, which is heavily affected by the number of users on the same network, MCPTT ensures high-quality communications as it uses the VoLTE network and supports a stable group communications service - even when there is a surge in users - through the application of Group Communication System Enabler (GCSE) based on evolved Multimedia Broadcast Multicast Service (eMBMS).  GCSE is an eMBMS-based group communication technology adopted by 3GPP. eMBMS is a technology that can transmit large-volume multimedia content to massive users at once over wireless LTE network.

For this reason, emergency service organizations such as police and fire fighting agencies in countries like Korea, the United States and Great Britain called for the development of MCPTT, and as the result the technology has been standardized in March 2016 by the 3GPP standard body through close cooperation and active participation of these relevant organizations.