On April 6, Syniverse hosted its third webinar on one of the most rapidly growing areas of LTE – Voice over LTE, or VoLTE. The sessions, titled “Making VoLTE Interconnect Work” followed the first webinar we held last December, “Lessons Learned: Implementing VoLTE Roaming,” and included me along with four other Syniverse VoLTE specialists: Brian Beach, Senior Technology Manager, Next-Generation Solutions; Faron Achziger, Senior Product Manager, Advanced IPX Services; Les Goldman, Senior Product Marketing Manager; and Mike Carnes, Senior Product Manager.
We were delighted to draw a large number of attendees and receive a lot of questions during the sessions. To give a sample of some of the webinar highlights, in this post I’ve selected a few questions that I think are of the most interest and featured them below. These only represent some of the highlights, however, and I invite you to listen to the full webinar recording and check out all our slides.
We hope you find this continuing discussion on VoLTE stimulating, and we look forward to building on it with more webinars this year. If you have any suggestions for VoLTE topics, I would love to get them in the comments section below.
Questions from “Making VoLTE Interconnect Work”
Are there any operators doing VoLTE interconnect trials, and are there any commercial deployments?
Faron Achziger: Over the past few years, we’ve been fully immersed with VoLTE trials, and they’ve primarily been roaming trials. As operators have deployed their IMS cores, they have really been focused on getting the service to work in their home market first. Once they have done that, their next priority has been ensuring that their subscribers have the same quality of experience when they roam outside their home network. As a result, a lot of the trials that we’ve been involved with so far have pertained to roaming. However, we’re currently involved with a number of interconnect trials in North America as well as other regions, and this number is starting to accelerate as operators are increasingly making it a priority to provide IMS services like VoLTE, ViLTE and RCS. Many of them want to deploy these services this year and get their trials underway. So, although we’ve had a number of commercial launches for VoLTE roaming, I expect to see a launch for VoLTE interconnect here in the near future.
A challenge for VoLTE Interconnect is number portability management. How is this handled?
Mike Carnes: The GSMA is considering some options for number portability resolution and working on an industrywide solution for this now. I think where we’re heading is that we’ll see independent IPX providers implement a variety of number portability resolution methods. For instance, we could rely on local number portability data local within a network or home country to provide number portability resolution. Or we could rely on third-party number portability sources on a per transaction basis. These options aren’t fully defined yet from an industry perspective, but at Syniverse we have developed our own views internally and our own solutions for addressing this problem.
How does the Syniverse IMS core work with a mobile operator’s IMS core?
Faron Achziger: The Syniverse platform or IMS exchange platform interoperates with mobile operators’ networks through the SIP Protocol typically. Using this protocol, we gather requirements from the operator as well as the partner network that the operator is testing with or deploying commercially with. So, initially the process consists of a lot of information gathering from the operator. We then apply this with the mechanics and the rules within our platform, for both the SIP Protocol and the media streams.
What impact does VoWiFi have for IMS?
Brian Beach: This is an extremely timely question because we’ve been seeing a lot of movement with VoWiFi. It’s a technology that’s been around for a long time. There was an effort to standardize it about a decade ago in an initiative called UMA, which was adopted by some operators but not widely. But the big game-changer was a combination of the 3GPP introducing a component called an EPDG and the large OEMs integrating this functionality into their devices. What an EPDG does is allow untrusted Internet access – that is, Wi-Fi – into an operator’s IMS core. So, this enables a single IMS framework for VoLTE, ViLTE, RCS, etc., and it also enables a bridge to VoWiFi. Another benefit is that things like single radio voice call continuity or handover from one network to another are possible. And one more benefit is that HD-quality calls can be enabled between VoWiFi subscribers to VoLTE subscribers.