Читать книгу Shaping Future 6G Networks - Группа авторов - Страница 51

5G brings a shift from tightly specified protocol interaction between different systems and entities within the mobile network, to interaction based on APIs. While these may be specified, they may also evolve rapidly. The API‐based network may also lead to fragmentation, as different approaches to APIs for specific integration requirements emerge.

Until 5G, mobile network architecture had followed a broadly similar template. Functional entities are defined, with interfaces specified that allow communication and information transfer between them, according to rules and criteria. The interfaces have been implemented using standardized protocols. As such, a vendor can develop a solution to meet functional criteria and then use the required interfaces to connect to the relevant adjacent nodes. Protocols used have included the Signaling System No. 7 (SS7) family of interfaces, session initiation protocol (SIP) and Diameter, as well as others such as H.248, and so on.

Access to mobile entities has also been possible from external systems. While there have been different approaches to this, the general principle is that application programming interfaces (APIs) can be exposed, enabling third‐party systems and processes to control, at some level, services and procedures within the mobile core. Examples of such initiatives include Parlay, among others. Although there is a long history of such initiatives, adoption and uptake were relatively slow and constrained, but, today, RESTful API exposure is relatively commonplace.

5G is different, because API exposure has become fundamental to both internal and external systems. Third‐party access will be enabled by RESTful APIs, but this now also extends to internal communications. This is due to the adoption of the new service‐based architecture (SBA). Functions that are internal to the 5G core – network functions (NFs) – will connect to others via service‐based interfaces (SBIs), which will also present RESTful APIs [25]. “It is this change that enables the network programmability, thereby opening up new opportunities for growth and innovation beyond simply accelerating connectivity” [26].

This is an important shift – not only for how 5G networks will be built and for how innovation from operators and third parties will be enabled but also because it points to the likely growth in openness of all subsequent generations of mobile technology. With APIs available internally and externally, there may be less need for the standardization of such interfaces and, instead, more emphasis on a functional definition, not a specified definition.

As such, it can be seen that 5G networks are inherently more open than any previous generation and that 6G is likely to adapt and build on the same principles. Vendors and solution providers will be able to create their own APIs – for internal and external consumption. As such, other interest groups will, in all likelihood, align around the needs of vertical industries (as has already happened) and hence drive APIs and SBIs defined according to their needs, in addition to any defined by a globally focused standards organization – or any others that emerge, for that matter. They may derive their own interpretations of IMT‐2030 in order to accelerate time to market and alongside efforts from 3GPP.