5G Roaming: What should we do now?

By Mehmet Turunc, Head of 5G Roaming

As with the previous generation of wireless technologies, the goal of roaming is to keep seamlessly connected to a network, wherever you are. This is also the case for revolutionary 5th generation wireless communication technology, or simply called 5G, but this time it is much more complicated.

What does the industry need to do to create a standardized roaming implementation that covers international 5G use cases for Enhanced Mobile Broadband, Massive IoT and Ultra Reliable Low Latency Communications?

Most likely, you are struggling to answer some of the following questions:

  • Are the standards completed? 
  • Which component and function of 5G should we implement?
  • Should we wait and learn from early operators’ launches?
  • When should we launch 5G and 5G SA roaming? Are IPX providers ready to support us?

Don’t worry, you are not alone.

In this first installment of our 5G Blog Series, we will begin to explore these questions and provide you with answers to help you better understand 5G roaming implementations. 

5G Stand Alone (SA) comes with fundamental changes from an architectural point of view. Here are a few of the critical changes: new virtualized specialized functions, new protocols, enhanced built-in security from the beginning, HTTP-based queries, JSON data structure formats, and RESTful APIs.

So, mobile network operators should adapt themselves to software-based architectural changes, as the industry is very well aware of network function virtualization and software defined networks.

From a roaming point of view, MNOs will need to interconnect to each other as they are doing for 2G, 3G and 4G networking. Of course, there are some changes and these are listed below.

1. Define your 5G investment

MNOs will first define their 5G architectural model as Non-Stand Alone (NSA) or Stand Alone (SA), which is fundamentally important for roaming implementation.

– If NSA is selected, the 5G core architectural model is Evolved Packet Core (EPC) which is used in existing LTE deployment. In this option, Diameter signaling continues to be used for roaming and operators will need to prepare for extensive bandwidth increases, reliable infrastructure and working closely with IPX providers for support.

If SA deployment is selected, a completely new protocol -HTTP/2- will be used for 5G signaling. Operator-to-operator interconnection will be done through a new module Secure Edge Protection Proxy (SEPP). MNOs can either deploy their own SEPPs to do the interconnection with their IPX provider‘s SEPP or rely on a hosted SEPP function provided by their IPX provider. Standards are not yet completed, however, all options discussed in the 3GPP and GSMA working groups are supported by iBASIS.

Source: GSMA Roaming Implementation Guide NG.113-v1.0



2. Define and prepare your roaming strategy implementation

IPX providers will be key and critical to help you to connect to 5G Roaming partners and get broad and redundant coverage to meet your specific needs. Either you can define your 5G roaming partner yourself or iBASIS could support in finding the most suitable one thanks to its wide customer and partner base.

Test your roaming functions

iBASIS has a lab environment that supports NSA and SA deployments. Various test cases are prepared and MNOs will be supported step by step. Especially for 5G SA testing, the iBASIS 5G Sandbox is ready to support the community.

Analyze your roaming data

Award-winning business intelligence tool InVision™ provides smart analytics that can help you understand usage and behaviors, and optimize customer experience. With near real-time visibility and understanding of the successes or failures of every activity at every network location, you can identify 5G customers and their behavior.

Plan your strategy with security at the core

5G security is certainly a complex task and directly effects roaming interconnection models. 5G and security are intertwined: from the beginning, the idea is to provide end-to-end encrypted communication. Advanced certificate verification with transport layer security, key & parameter exchange or PRINS (PRotocol for N32 INterconnect Security) on all HTTP messages can either be provided MNO to MNO directly or through the IPX provider.

3. Launch and commercialize your roaming agreement

When all the tests are completed with clear successful outputs, you can commercialize your 5G roaming agreement with your roaming partner.


As with all new technology adoption cycles, the learning phase is critical to understanding the multiple options and scenarios, the technical and commercial barriers and unplanned implementation pitfalls. If you have not yet joined our VoLTE & 5G Roaming Community, we encourage you to join the LinkedIn group and participate in the next roundtable session to gain insights from industry leaders as they go through the adoption cycles and learning phases as well.

iBASIS is prepared to support a seamless roaming experience for our partners providing a range of different use cases and various architectural options. We are ready to support the industry and continue to give guidance to MNOs. As one of the leaders in international 4G communications, iBASIS will always remain focused on helping our customers to “Be There First” in 5G.

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