MSF: Progress in Voice-over-LTE

Voice over LTE (VoLTE) is making progress with multiple vendors now demonstrating interoperable platforms and major carriers demonstrating successful interconnects.


Last month, the MSF (MultiService Forum), backed by the GSMA, hosted a VoLTE Interoperability Event held simultaneously in Dusseldorf, Germany and Beijing, China. VoLTE calls were successfully completed within each host site (including MMTel services) as well as between the host sites to demonstrate network inter-connect. LTE Roaming between host sites was successfully demonstrated, utilizing dynamic policy control between home and visited networks employing DRA's (Diameter Routing Agents). Multi-vendor testing, a key component of all MSF IOT events, was conducted at each site, incorporating interworking between different vendors' UE, eNodeB, SeGW, EPC, IMS/MMTEL, DRA and PCC technology.


The MSF VoLTE interoperability event focused on validating the GSMA VoLTE recommendations for UE to Core Network interoperability, incorporating LTE, EPC, PCC, DRA and IMS core elements in a multi-vendor deployment. Test scenarios included VoLTE basic interoperability, global Roaming and Interconnection as specified by the GSMA.


Vodafone hosted the European event at its Test and Innovation Centre in Dusseldorf, Germany and China Mobile hosted the Asian event at its Research Institute Laboratory in Beijing, China. The Event was sponsored by GENBAND, Huawei, ZTE, Alepo, Bridgewater Systems, Cisco and WiChorus, a Tellabs Company, with participation from Acme Packet, Alcatel-Lucent, Codenomicon, D2 Technologies, EXFO, IPneo, JDSU, Metaswitch, Samsung, Stoke, Traffix Systems and VSS Monitoring. Observers included ETRI, ETSI, NCS, NTT, Verizon and Videotron.


"The MSF VoLTE event successfully validated the GSMA VoLTE initiative by demonstrating that an IMS-based solution for Voice over LTE can provide global roaming and interconnect solutions for Operators. We are very pleased to see so many global participants coming together for such an important multi-vendor event. The latest in the series of MSF LTE Testing has surpassed our expectations," said Kyu-Ouk Lee, MSF President, ETRI.


“The completion of successful interoperability testing should give the industry, and in particular GSMA member organisations, the confidence to progress their work on VoLTE deployments as they move forward with their LTE deployment plans. The GSMA thanks the MSF for organizing and administering such a comprehensive event, and we will continue to work together to implement improvements and extend the level of interoperability of VoLTE implementations in the future,�? said Dan Warren, Senior Director of Technology, GSMA.


For its part, GENBAND noted that its A2 Communications Application Server was tested in the role of VoLTE Telephony Application Server (TAS), where it provided Multimedia Telephony (MMTel) services with IMS to LTE mobile devices through 3GPP standard ISC and Ut interfaces. Through the A2, GENBAND tested TAS functions using the ISC interface and successfully executed MMTel services to LTE devices via a third party IMS core. GENBAND also tested the Ut interface directly with the LTE devices for MMTel service configuration.


STOKE, which supplied its high performance Security eXchange gateway, contributed in building and validating practical LTE network use cases such as secure association and encryption of VoLTE traffic from the radio access network to the evolved packet core. Stoke's Security eXchange encrypts user and control plane traffic between LTE base station (eNodeB) devices and the core network at line rate. This allows operators to mitigate the strategic risks inherent in deploying all-IP LTE networks and improves their ability to scale their networks to accommodate growth in traffic and eNodeBs. http://www.msforum.org/interoperability/VoLTE.shtml