The biggest challenge in transitioning from traditional RAN to Open RAN is the integration of Open RAN components. Guess why! absolutely due to RAN itself getting disaggregated into smaller pieces coming from different vendors (multi-interoperability) in different layers (Horizontal and Vertical) from Control, User to Management.
Below is the conclusion, I quoted from Tietoevry’s white paper about Open RAN Integration. You can think about integration as “connecting the pieces and checking that it works” OR “modifying the pieces until the whole system works”.
In general, if the system is working fine with a good performance, It means the integration is done successfully.
Open RAN is a multi-vendor solution there are products supplied by those vendors that are intended to be put together into a complete solution.
The OpenRAN integration focus areas can be divided into different dimensions:
- Vertical integration
Implies to make sure that all SW components perform sufficiently on the selected infrastructure products (e.g. COTS).
The most important topic is accelerators. - Horizontal integration
This integration is captured to make “application” components (e.g. RU, DU, CU) to achieve the expected application functionality, performance, and other characteristics.
The most important topic is the Fronthaul interface between RU and DU. - Operational integration
This is the integration needed to ensure that the solution can be operated in the way the MNO decides. I.e. that needed data exchange to and from operational support systems and tools (SMO/OSS/BSS etc) as well as the functionality of the operational systems can be achieved to reach OPEX targets.
The most important topic is the Cost of operation (OPEX). - Multi-RAT integration
This is the integration needed to make sure the solution can interwork with other wireless standards as needed in the intended deployments to be supported.
Finally, When we are talking about System Integration, it can be
- Independent Systems Integrator.
- System Integrator promoting an Open RAN solution.
- SI as part of vendor eco-system.
- Vendor takes on Integration.
- MNO acts as the Integrator.