5G Roaming Suite: from hosted SEPP to the future

Madrid, 20 June 2023.– Recent years have seen the development and deployment of 5G. This evolution in the mobile communications ecosystem provides solutions for the current challenges and enables new use cases. With 5G being a reality that steadily reaches more users, with an increasing number of operators that launch their 5G SA Cores, it is now time to broaden the scope of 5G and look into the interoperability of different networks. It is time to tackle 5G Roaming.

Telefónica Global Solutions (TGS) has been providing international roaming services for over 15 years, both to the Telefónica Group with its operations spanning two continents and to independent MNOs all over the world. With the advent of 5G Roaming our mission to allow people to communicate all over the world, regains importance, as the change in technology is a challenge for all players. The 5G technology includes novelties in architecture and protocols. These affect both domestic and roaming operations and include in the later area, the introduction of http/2 as the signalling protocol and Security Edge Protection Proxy (SEPP) as the network boarder node.

“With the aim to democratize the access to 5G Roaming to all kinds of operators, the solution deployed by Telefónica Global Solutions is based on the concept of the Hosted SEPP. We provide our customers with the SEPP infrastructure, the SEPP operation, the connectivity to Roaming Partners and the management of the technical relationship with roaming partners “as a Service”. In this managed approach we alleviate our customers from the burdens of international connectivity while maintaining all communications under their identity.”

Carlos GAMBOA
IPX PRODUCT MANAGER

The adoption of 5G Roaming will require MNOs to adapt to the new standards. In our quest to facilitate international communications and serve the needs of the MNOs, at Telefónica Global Solutions we have deployed our 5G Roaming Suite.

5G Roaming Suite brings together all the necessary elements to enable successful 5G Roaming. Two elements are key; the 5G Roaming Signalling Service and the Data Roaming Service. While the Data Roaming Service, which goes back to the times of GRX and 2G Roaming, is a well-established service that handles the user data in roaming for all technologies, the 5G Roaming Signalling part is brand new and has required the deployment of new network elements. Furthermore, the 5G Roaming Suite is enhanced by our Service Opening service and Roaming VAS in roadmap.

5G Roaming suffers currently from an uncertainty in the standards. While there is an approved standard for 5G Roaming, Bilateral TLS, this solution is only suitable for large operators who are able, both financially and technically, to operate a SEPP node and maintain the connectivity to all its roaming partners. With the aim to democratize the access to 5G Roaming to all kinds of operators, the solution deployed by Telefónica Global Solution is based on the concept of the Hosted SEPP. We provide our customers with the SEPP infrastructure, the SEPP operation, the connectivity to Roaming Partners and the management of the technical relationship with roaming partners “as a Service”. In this managed approach we alleviate our customers from the burdens of international connectivity while maintaining all communications under their identity.

To enable our 5G Roaming Signalling Service we have deployed a pair of virtualized SEPP nodes in Frankfurt and in London, with a second deployment in America under development. The European deployment is already connected to a larger American customer, which is being hosted, and an important European operator which is running its own SEPP. In this configuration first test traffic is being exchanged. While similar scenarios have already been tested, in our trial stage we are using actual devices attached to the visited networks RAN. Additionally, the current works are strongly taking into consideration the management part required for 5G Roaming. In this category falls the exchange, use and revocation of the participants’ cryptographic certificates. Being security included by-design in 5G it is important to ensure that the mechanisms are kept strong also at management level. Just the exchange and validation of certificates is a sensitive task where participants must have a clear understanding and a strong commitment. It is the latter that we ensure at TGS providing the necessary scale to prevent customers being overwhelmed by these administrative tasks.

TGS’ 5G Roaming Suite offers our customers a gateway to 5G Roaming, which, as a managed Service, provides a reduced time-to-market, requires less resources (human and financial) from the operator, avoids complexity when scaling up and builds upon our experience and expertise.

5G Roaming still has a long path to go for it to be commonplace, and the GSMA has to address the standardization issues around the use of roaming hubs, hop-by-hop TLS, PRINS and other aspects. However, the deployment made by Telefónica Global Solutions shows the way forward for any kind of operator willing to engage in 5G Roaming, irrespective of size or financial capacity. 5G Roaming is a reality.

Proof of our commitment to 5G Roaming is the recognition of Telefónica Global Solutions as a Champion 5G Roaming vendor by Kaleido Intelligence in their latest report 5G Roaming.

Carlos GAMBOA
IPX PRODUCT MANAGER