How Syniverse overcomes the challenges of 5G roaming

We catch up with Pradeep Bhardwaja (pictured), Senior Strategy Director & Head of Industry Standards at Syniverse and Mike Stewart, Vice President, Product Management to talk about the challenges of 5G roaming, the evolution to 5G standalone roaming and the new business models that 5G standalone will enable.

Pradeep Bhardwaja

Senior Strategy Director & Head of Industry Standards


Mike Stewart

Vice President, Product Management


Q1 – What are some of the challenges mobile operators are currently facing with 5G non-standalone roaming?

Stewart: From a 5G non-standalone (NSA) perspective, the industry is seeing a good uptake in operators interested in launching 5G NSA because of the short leap to move from 4G roaming. Non-standalone leverages the existing IPX and the existing diameter signalling infrastructure. The only real variable there is that you have the 5G new radio.

Diameter signalling needs to support additional parameters that allow the new radio interface to be enabled in a roaming scenario. Ensuring that the diameter signalling configurations are completed correctly is a key step to enable 5G NSA roaming.

Another issue is VoLTE, which has had a very slow uptake in roaming. With 5G non-standalone, whilst 3G circuit switch fallback for voice may be an option in the short-term, it creates a big dependency, so VoLTE and VoLTE roaming both should be prioritized for early deployment.

Even with these issues we see that operators are choosing to launch 5G NSA roaming services before 5G SA so that they can offer their subscribers an enhanced roaming experience.

Q2 – What is the differentiation of the 5G roaming transaction under non-standalone as compared to an LTE transaction?

Stewart: The key differentiation is the use of the 5G new radio in 5G NSA compared to 4G LTE. 5G NSA still leverages the same Evolved Packet Core that is required for LTE/4G. Operators are working to expand their 5G coverage so that they can offer 5G speeds to their subscribers today while still working on deploying the 5G core. The challenge is how to identify the 5G-NR usage in 5G non-standalone distinctly from 4G LTE Radio usage.

As operators deploy 5G NSA, VoLTE will become a critical service to ensure that voice roaming is in place. VoLTE home routed S8 (S8HR) is the most popular solution and we have not seen a significant uptake of local breakout for VoLTE in a roaming scenario due to various challenges with lawful intercept and other headwinds.

Q3 – What is the status of 5G standalone roaming and what obstacles do MNOs face?

Stewart: The first major challenge is the adoption of 5G core. As of mid-2022, there are only 23 operators today globally that have launched 5G cores into their production environments. There is a limited set of operators that can work together to do the necessary testing and pre-work needed before launching 5G standalone roaming.

The industry has cleared phase one from GMSA with regards to MNO-to-MNO roaming, but we still have unanswered roaming VAS questions. There are certain services that support roaming like roaming analytics, but other roaming VAS services are currently unavailable for 5G standalone. The industry is very nascent in the testing of proof of concepts with regards to simply basic roaming services under standalone.

For operators that have already launched 5G standalone cores, as well as those operators who are just launching their non-standalone 5G new radio, there is still a lot of work to be done on coverage.

We see that operators are showing interest in setting up 5G SA lab trials and proof of concepts to start getting the ball rolling and get through some of the basic roaming challenges with the standalone deployment.

Q4 – Aside of the signalling protocols, can you tell us about the security requirements as we migrate to the 5G standalone environment?

Bhardwaj: 5G will be a big enabler for various market verticals as well as for the economy, society, smart cities, and Internet of Things. With 5G opening these vast opportunities in different domains, security becomes critical because the implications of security failure would be huge. That’s why there is a lot of concern around security, in addition to privacy and trust in 5G.

As 5G standalone is based on service-based architecture, we need to talk about the security aspects of service-based architecture, as well as the different security needs of multiple verticals. An automotive industry may have different security needs than healthcare or manufacturing.

Then there are different architecture options that are being discussed within GSMA. One school of thought says there must be end-to-end encryption, but that brings its own challenges. Operators will not be able to fully monetize the different services and benefit from the roaming value-added services in the same way as they do today within end-to-end encryption. Complete end-to-end security would come at a significant cost to the ecosystem.

The industry will have to come up with the right balance between security considerations, operation considerations, and business considerations as they all deliver huge value to the ecosystem.

Q5 – What does 5G standalone enable from a monetisation perspective for mobile operators?

Bhardwaj: When we move to 5G standalone it opens a plethora of opportunities in different verticals. It will be underpinned by new network capabilities such as network slicing, edge computing, virtualization.

If you think about it, Network slicing is a huge capability that 5G standalone brings which would make 5G networks very attractive for enterprises. That would certainly expedite the market adoption for 5G standalone.

In terms of monetising, you can also create new business propositions including enhanced mobile broadband type of opportunities. In addition, there are also opportunities with Massive IoT and Ultra-reliable low latency communication services.

Q6 – What are some of the challenges around voice services and messaging in regard 5G standalone?

Stewart: The first challenge is getting VoLTE in place with your 5G standalone enabled roaming partner. That is a requirement. The second piece of 5G voice is going to be voice over new radio (VoNR). Voice over new radio still uses the IMS core infrastructure just like VoLTE, but it uses the 5G new radio to enable the voice path.

I suspect VoLTE is going to be around for a while because 4G is going to be around for a while. We will see 5G and 4G enabled networks in the traditional mobile network sense that are both going to support VoLTE as well as voice over new radio

Q7 – Can you tell us about the new network and business models that 5G standalone will enable?

Bhardwaj: I talked about enterprises looking to embrace the 5G technology. In that context, we must explore all these new revenue models. We must explore new market drivers for these enterprise markets.

Connectivity has always been the bread and butter for operators. But now, with the industry moving to 5G, I think the industry has an opportunity to evolve this even further and monetize Connectivity as a Service.

5G can extract and collate a lot of data with huge value to enterprises. Data-based business models is another opportunity area. In terms of different models, private networks are the first one that comes to my mind.

We talked about all these different stakeholders now coming to the party with 5G standalone, which means that there will be more opportunities for revenue sharing, for different reseller models and so on because the 5G value chain will expand.

Stewart: Every mobile technology through 4G has really been about a person with a phone. We have seen some growth of IoT in 3G and 4G, but at the end of the day the monetization and the focus has been on a person walking around with the device in their hand.

5G is going to change all that. I think that the industry will see a huge shift of use cases where previously it was really all about people carrying phones to being about the connectivity of things and the new industry verticals that need this capability. That is the biggest shift that 5G is going to bring to the table.