As some industry players are beginning to suggest that the benefits of 5G are now moving from theory to reality, work continues to fully develop the underlying network capabilities to support these aspirations. There are many advancements in terms of available technologies, but also in the fundamental approach to developing these new networks.
Many major telecoms operators and vendors have joined together to support moves to split previously integrated network solutions and platforms into independent and interoperable Whitebox hardware, middleware/Operating Systems, and software or Virtual network functions.
The Radio Access Network (RAN) has been identified as an area that will particularly benefit from independent combinations of hardware and software, allowing for more competition in the ecosystem and the capability for network operators to choose optimum solutions, specifically for their network. This is not without risk, as guaranteeing performance and managing complexity are inherent challenges.
To help with this, the O-RAN (Open Radio Access Networks) Alliance was formed in 2018 to define common interfaces between systems, aiming to reduce complexity and accelerate deployment of multi-vendor RANs.
As these new networking developments are intended to align with the objectives of 5G, the need for tight synchronization remains. In practice, this has been seen to result in Network Operators requiring incoming systems to prove they have the underlying capability to meet strict timing requirements, such as to ITU-T G.8273.2 Class-C specifications.
Equally, vendors for Open RAN networks need to be able to validate interoperability in a ‘gold standard’ environment (including negative testing) to ensure fundamental time transfer requirements in the Synchronization plane (S-plane) are met in addition to Control, User and Management functions. This is acknowledged within the O-RAN alliance, and working groups continue to improve specifications and methodologies in these areas.
Calnex’s latest primer, O-RAN: Proving Time Accuracy for the Fronthaul Network, provides an overview of O-RAN, descriptions of its technical specifications for the Synchronization Plane (S-Plane), and test recommendations to support a robust and efficient network. This document examines the four synchronization configurations from the O-RAN’s official technical specifications, the time and frequency error budget from two key ITU-T standards – G.8275.1 and G.8273.2, including the Class C T-BC and T-TSC with PTP and SyncE timing, and testing S-Plane performance and 5G synchronization. Get instant access to your free O-RAN primer below: