About Cisco CISCO BroadSoft is now part of Cisco Learn More

With a 10X increase in transmission speeds and a significantly lower cost per bit, Long-term Evolution (LTE) represents a tremendous opportunity for operators given the prospect of converting more than 4 billion mobile subscribers worldwide to 4G or fourth-generation technology. The evolution in wireless communications is driving operators to change the way voice services are delivered.

Voice over LTE is an important topic for providers today. LTE is all about data so trafficking circuit-based voice services onto IP networks is a big issue. There are a number of technical and business challenges associated with Voice over LTE. While there are questions over when Voice over LTE will be deployed, one of the big technical impediments until recently was a unified standard.

A few weeks ago a consortium of service providers, equipment vendors and device manufacturers came together in support of a standard for delivering voice and SMS services on LTE networks, One Voice. The One Voice specification will use components of the existing IP Multimedia Subsystem (IMS) framework (which already defines how to provide data, voice and multimedia content over IP) to route voice calls between circuit switched and IP networks…meaning LTE mobile calls will become VoIP calls.

Prior to One Voice, a competing approach — the VoLGA (Voice over LTE via Generic Access) initiative — was put forth as an interim LTE voice solution using existing circuit-switched networks …instead of IMS. VoLGA supporters claim this would allow operators to get there sooner rather than later. While we understand the problems VoLGA attempted to address, we think they’re greatly exaggerated. Since the One Voice announcement, many in the industry are now questioning the livelihood of VoLGA.

In our opinion, VoLGA’s time has passed. Here’s why…

  • T-Mobile is the only operator backing VoLGA. Now compare that to the list of heavy hitters behind One Voice…AT&T, Orange, Telefonica, TeliaSonera, Verizon, and Vodafone.
  • The addressable market for VoLGA is minuscule compared to that of One Voice. Handset manufacturers and network equipment vendors follow the lead of service providers. Given the first point, it is obvious where the opportunity is.
  • Given VoLGA is a temporary solution, vendors are not likely to invest in it — innovation will occur with One Voice though.
  • IMS is MORE mature than what VoLGA proponents pushed. BroadSoft has more than 50 live IMS deployments worldwide and with an inside view of 450+ providers’ network roadmaps, we can validate this is real. Many carriers in the US and most European providers have already deployed IMS.

As providers continue to lose landline assets and look to collapse their networks into one, IMS is critical. Since IMS simultaneously serves broadband wireline and LTE wireless networks, this provides operators with a path to service convergence. Fixed-line providers have been moving in this direction for some, and now converged and mobile operators need to follow suit. This is huge opportunity for them.

BroadSoft believes One Voice is the best approach for delivering voice and SMS services on LTE networks and will help accelerate the process of moving to all-IP. Providers should not be sidetracked with an interim solution that doesn’t address the primary goal.

UPDATE - It's really dead now - Ericsson leaves VoLGA Forum, from Unsprung: http://bit.ly/4nSnAI

About the Author