Roaming for Voice over LTE

[cellular news] The NGMN Alliance has announced an agreed recommendation to ensure roaming for "Voice over LTE". The agreement was reached based on an outcome of the NGMN Task-Force on Voice over LTE.

NGMN stated that the Alliance and its members are firmly committed to IMS Voice as the target solution for Voice over LTE. Furthermore, NGMN recognises the benefits of recommending a migratory non IMS voice solution that guarantees voice roaming with LTE handsets whilst allowing use of LTE data roaming in the same device.

The NGMN is recommending that in all LTE devices that support GSM or UMTS and that provide the voice service, Circuit Switched Fall Back (CSFB) shall be implemented as a minimum requirement for supporting voice . The CSFB implementation shall be compliant to the 3GPP specifications. In addition, if a Mobile Network Operator operates a network comprising LTE plus GSM or UMTS and if this MNO aims to provide a non-IMS voice service as well as an LTE data service to visiting subscribers utilising an LTE device, then it shall, as a minimum, support CSFB for voice. The implementation shall be compliant to 3GPP specifications.

The agreement on voice roaming is already the second achievement of the NGMN Alliance in the area of voice and SMS roaming for LTE.

"Roaming for voice from day one of the next generation mobile networks operations was a key requirement stated by the NGMN Alliance from the beginning. It is one of the major challenges to be addressed on the way to successful next generation services launch." said Dr. Peter Meissner, Operating Officer of the NGMN Alliance. "The proposal agreed is an excellent achievement and avoids fragmentation of solutions on our way towards the ultimate IMS-based Voice over LTE solution."

"Roaming is an essential part of the customer experience and needs to be maintained with every new generation of technology," said Alex Sinclair, CTO of the GSMA. "The agreement on migratory solutions achieved by the NGMN Alliance will ensure a smooth transition for those operators deploying LTE in a non-IMS environment, and complements the work of the GSMA VoLTE initiative on the IMS-based voice implementation."

Roaming for Voice over LTE