TGS SEPP MEDIATION: Unlock interoperability between operators for 5G SA Roaming connections

Madrid 19 Februray 2024.- The year 2023 has ended with almost 130 operators from 57 countries having successfully launched 5G SA networks in their domestic markets, but the international implementation of 5G roaming has encountered several challenges. From this experience, we’ve learned first-hand the difficulties that any operator can face, especially when it comes to the interconnection issues and one of our answers to this challenge is the TGS SEPP MEDIATION, part of the TGS 5G Roaming Signalling service.

Ensuring interoperability between different operators and networks is much more complex than it seems:

• Different vendor equipment, configurations and software versions can lead to compatibility issues.
• Differences between countries in terms of spectrum
• Distinctions between countries in terms of regulatory compliance and security configurations that need to follow the GSMA standard.

So, what can you do as an operator to ensure that your connection with other operators runs smoothly?

Our experience can be your most valued asset.

As a global 5G roaming enabler, we can alleviate these difficulties for all operators involved in roaming and formulate solutions that stand out in the industry.

Telefónica Global Solutions has been at the forefront of the 5G wave, proving ourselves and our solutions in PoCs between Europe and Latin America, our core regions.

From this experience, we’ve learned first-hand the difficulties that any operator can face, especially when it comes to the interconnection issues mentioned above, and one of our answers to this challenge is the TGS SEPP MEDIATION, part of the TGS 5G Roaming Signalling service.

What is TGS SEPP MEDIATION?

The TGS SEPP MEDIATION is a functionality of our SEPP cores, and standard feature of our TGS 5G Roaming Signalling service, that allows engineers to configure and correct policies in both sides of the interconnection between operators.

Easy to describe, but harder to do. Let’s get into the technical details.

The policies and configurations for interconnecting the 5G networks of two operators, typically from different countries, must follow the standards set by the GSMA. This is a technical process whose novelty and complexity is posing significant challenges to engineers at operators and carriers worldwide.

Our SEPP MEDIATION enables MNOs to resolve the MEDIATION issues between PLMNs by manipulating the inter-PLMN messages. Our service performs HTTP/2 signalling API message mediation between Network Functions, resolving interoperability issues for 5GC inter-NF

Topology Hiding vs. SEPP MEDIATION

 In the context of a Hosted SEPP solution our choice has been for SEPP MEDIATION as this functionality enables us to perform changes in the regular expression of the http messages. Topology Hiding enables us only to perform changes such as NF Instance ID or NF Service Instance ID.

SEPP MEDIATION application

 Typical applications of this function are to correctly identify FQDNs and/or IP addresses for the use in roaming scenario. In a Hosted SEPP scenario, we can modify the internally used FQDN to accommodate for one specifying the MNC-MCC identity of the operator. In the same scenario we might change local private IP addresses to FQDN expressions that allow resolution outside the home network.

We help 5G core engineers quickly resolve discrepancies by enabling dynamic configuration of mediation policies that can be applied to both request and response messages.

TGS SEPP MEDIATION provides significant benefits to its users

 Firstly, MNOs and operators can trust Telefónica Global Solutions’ expertise in 5G at all stages of the process, not only because of our extensive experience as a global roaming enabler, but also as a pioneer in the implementation of 5G SA both domestically and internationally through our Operating Companies and our TGS 5G Roaming Signalling service.

With the Telefónica Group as one of our customers, we have first-hand experienced the difficulties faced by each of the operators that are now embarking on the exciting journey of 5G SA Roaming.

Secondly, from a technical point of view, we will be at your side for all the crucial steps in the interconnection process:

• We help you fill the gaps in 5G SA roaming expertise.
• We facilitate vendor feedback and update requirements if there are specific vendor interoperability issues for 5GC inter-NF communications.
• We provide your engineering team with a comprehensive framework for configuring the mediation policy rules to be applied to HTTP signalling messages. We guide your team through all the different policies and ensure that GSMA standards are covered from both sides.
•  We allow for dynamic configuration so that it can be adjusted on both request and response messages from both ends of the connection.

In short, MNOs and operators can rely on our mediation to ensure that all interoperability and connections are handled correctly.

Telefónica Global Solutions offers what we do best: Solutions.

Since 5G SA is a huge leap in technology and knowledge, it requires immense resources and know-how, which, being so recent, is hard to come by. On the other hand, 5G SA is growing exponentially and the acceptance in the markets where it’s already deployed is huge. No operator should be left behind.

TGS SEPP MEDIATION as part of our TGS 5G Roaming Signalling service seeks to simplify one of the most complex issues for you: smooth interoperability between countries, operators and vendors.

Through our solution, we help you accelerate strategic ROI development and everything you need to jumpstart their 5G SA roaming expansion. We support product managers identify and fix feature enhancements, but most importantly, we take care of 5G core engineers to quickly resolve inconsistencies so that your 5G SA roaming services are uninterrupted for your customers.

_{By Verónica León González
TGS Technical Product Manager}