CCA ANNUAL CONVENTION, ORLANDO, FLORIDA: A panel of equipment vendors noted regional US operators can use VoLTE technology to boost spectral efficiency and recycle old voice spectrum for LTE to meet growing capacity needs, but must first work through technical hurdles related to location-based services.

Josh Wigginton, VP of product management at Interop Technologies (pictured, second from right), explained one frequently used VoLTE network roaming model, known as S8 Home Routing, sends all traffic back to the home network for processing. He noted the setup presents a problem for a number of services which rely on location data.

“What happens if I’m a Bluegrass Cellular customer and I’m in Puerto Rico, and I call 911? So there is an issue…you need to break out that emergency call local[ly] in the network, but the way it’s designed is everything goes back home.”

“If that’s all going back to the [home] network but you’re roaming somewhere else, those are some of the challenges that need to be solved around VoLTE.”

Time to adopt
Tier one operators Verizon, AT&T and T-Mobile US have all deployed VoLTE on their networks, and Sprint recently said it’s planning to do the same by the year-end. But small and rural operators have been slower to adopt the technology.

With the VoLTE ecosystem of equipment and devices rapidly maturing, Han Schiet, Nokia’s IMS product management director (pictured, second from left), stressed “the time is now” for operators to take on the upgrade. Huawei VP of sales William Levy (pictured, left) added smaller carriers must deploy VoLTE if they want to remain relevant in the market.

Wigginton encouraged operators to begin with lab trials and small proof-of-concept deployments on the network to make sure elements including devices, roaming and handoffs are all working well before launch. By doing so, “you’re solving all those problems in a controlled environment rather than with your subscribers,” he said.

Once the upgrade is complete, Schiet said future transitions should be smooth sailing: “Going from 4G to 5G, IMS is virtually unchanged. So going forward we are in good shape, but you have to go over that first bump to get your VoLTE deployed.”