Centralised-RAN is a centralised, cloud based new cellular network architecture that can be adopted by telecom operators to improve their quality of service with reduced capital expenditures (CAPEX), operating expenditure (OPEX), and energy consumption. ASTRI is developing a flexible and high system performance C-RAN solution to fulfil demanding industrial requirements.
Flexible C-RAN architecture
ASTRI’s C-RAN architecture is based on standard FAPI PS-PHY interface, which can easily integrate with commercial PS software. FAPI is a standard interface proposed by Small Cell Forum, which was adopted by most of the commercially available PS and PHY solutions for LTE/LTE-A base stations. Tasks partitioning for the server and remote units in C-RAN determines the trade-off between enhancing centralised coordination and reducing front haul throughput. ASTRI modular PHY processing architecture provides the flexibility to adopt different partitioning requirements depending on the deployment scenarios.
Our C-RAN provides new centralised baseband processing capability that realises advanced multi-cell coordinated algorithm. The algorithms, such as Coordinated Multipoint (CoMP), Inter-Cell-Interference (ICI) mitigation, and Active Antenna System (AAS) beam-selection, reduce inter-cell-interference and enhance spectral reuse with small cell size and heterogeneous networks deployment topologies. This has significantly increased the average system spectral efficiency.
Server side load balancing
Centralised processing units in C-RAN enables dynamic computational resources allocation. The processing entities for each cell are dynamically grouped and allocated to server side processors. During low traffic period, the system can shut down the redundant processors or switch the processing power to support other applications. This reduces energy consumptions and increases hardware utilisation of the computation units.
ASTRI flexible C-RAN architecture with centralized PHY and PS coordination
ASTRI’s C-RAN Reference Design
ASTRI is developing a C-RAN reference design which includes baseband pools and basic L2/L3 blocks for end-to-end networking to support:
(i) multiple cells with carrier aggregation (CA) which enables flexible bandwidth configuration for higher throughput,
(ii) dynamic cell combine and split with reduced operation expense and network optimisation, and
(iii) advanced MIMO techniques to improve spectrum efficiency and reliability. The deliverables include L1 link level simulation platform for the DL and UL transceivers, a commercial grade BBU pool reference design of C-RAN and a complete test infrastructure to verify and validate 3GPP requirements.
ASTRI C-RAN specifications
|Standard||3GPP release 10|
|Bandwidth||5 , 10, 15, 20 MHz|
|Duplexing||FDD, TDD (All UL-DL configuration and special sub-frame configuration)|
|# of users||256 users per sector
|Cell Size||Up to 10 km|
|Mobility||Up to 160 km/h|
|Throughput||DL: 300Mbps per sector
UL: 150Mbps per sector
|UE support||Category 1 to 6|
Beam-forming (TM7 and TM8)