In the early stages of wireless network evolution, each radio access technology (RAT) required separate infrastructure, including main processing units, baseband processing units, and electromechanical equipment. This approach necessitated multiple sets of equipment for multi-RAT networks.
To address these inefficiencies, Huawei introduced the SingleRAN solution, which evolved into the multimode base station (MBTS). Key innovations include co-cabinet, co-BBU, co-MPT, and co-BBP features, enabling streamlined hardware usage and multi-RAT support within a single system. This marked a shift from single-mode to multimode base stations.
What is Co-BBP?
Co-BBP refers to multiple RATs sharing one or more baseband processing units (BBPs), while independent BBP involves each RAT having its own BBP. Co-BBP is only supported in co-MPT multimode base stations. Huawei’s universal baseband processing unit (UBBP), introduced over a decade ago, supports multiple RATs and is compatible with all RATs, with the UBBPg supporting NR capabilities. For example, in V100R017C10, UBBP series include models like UBBPd, UBBPe, UBBPf, and UBBPg.
The UBBP can operate in both single-RAT and multi-RAT modes, but hardware or software limitations may restrict the combinations of supported RATs. For example, the UBBPg3 supports individual RATs like UMTS, LTE, and NR, but does not support their co-BBP combination due to software limitations in the current version. This evolution highlights the progression from an LTE-only base station to one supporting multiple RATs such as LTE, NR, and others.
Co-BBP Principles.
COMM+RAT Architecture.
Huawei’s co-BBP feature, introduced alongside co-MPT, allows multiple RATs to share a baseband processor. This is particularly relevant for multi-RAT base stations, such as those supporting LTE and NR, and requires a flexible baseband software design (COMM+RAT). Unlike earlier systems, where GSM baseband processing was handled by RF modules, newer base stations use dedicated BBPs, like the UBBP, for efficient multi-RAT operation. However, the GSM baseband processed by the UBBP is not detailed in this document.
The UBBP series boards vary in the RATs they support, with the UBBPe and UBBPf boards not supporting NR, while the UBBPg does. The COMM part enables CPRI connections and data exchange, while UMTS, LTE, and NR RATs implement their radio functions. Baseband resources are shared both within and across BBPs. The introduction of the BASEBANDEQM MO allows multiple UBBP boards to form a baseband resource pool, binding cells of different RATs (UMTS, LTE, NR) to corresponding baseband resources.
Summary
Independent BBP includes multiple BBPs such as WBBP, LBBP, and UBBP, while co-BBP requires the UBBP (UBBPg for NR support). Co-BBP necessitates co-MPT networking, while independent BBP allows both separate-MPT and co-MPT. Licenses are required for each RAT in co-BBP, with multimode licenses for additional RATs, while independent BBP typically requires no special licenses unless the UBBP is used.
Co-BBP Deployment.
New Deployment Scenario.
In the new deployment scenario for multi-RAT co-BBP:
- Hardware: Select UBBP models based on the required RATs.
- Software: Ensure software versions match the boards.
- Data Configuration: Include multiple RATs in BBP settings, add BBPs to resource pools, and correctly bind cells to baseband equipment.
- Licenses: Load licenses for each RAT as needed.
This setup allows deploying UMTS, LTE, and NR on the same BBP, facilitating resource sharing and efficient multi-RAT operation.
RAT Introduction Scenario.
In a RAT introduction scenario:
- Hardware: Choose the UBBP model supporting the desired RATs.
- Software: Ensure the software version matches the board’s requirements.
- Data Configuration: Update the BBP.BBWS parameter to include the new RAT (e.g., adding LTE to an existing UMTS configuration). Adjust the BBP.SRT parameter based on network planning. Note that changes cause a BBP restart. Bind new RAT cells to the correct baseband resources.
- License: Load a specific RAT license for the added RAT.
This process enables seamless integration of new RATs into existing UBBP setups.
Co-BBP License
The Co-BBP License in Huawei’s UBBP boards enables support for multiple RATs through specific license items. Each RAT requires two license types:
- First-Mode License: Activates support for a single RAT on the UBBP, such as GSM, UMTS, LTE FDD/TDD, NB-IoT, or NR.
- Multi-Mode License: Allows additional RATs to be supported simultaneously on the same UBBP.
For example, a UBBP first-mode license for LTE TDD is needed for initial RAT activation, and a multi-mode license is required for adding another RAT like NR on the same board.
