V-RAN Technology: A Promising Alternative for C-RAN with More Flexible Backhaul Options
Virtualized RAN (vRAN) enables operators to run Base Band Unit (BBU) functions on off the shelf hardware as virtualized network functions (VNFs). This can provide operators with the ability to avoid proprietary vendor lock-in as generic core and base station hardware can replace proprietary hardware. Currently Centralized RAN (C-RAN) uses a fixed Fronthaul split that requires a high capacity and low latency proprietary optical CPRI interface.
A vRAN extended to the edge of the network can support multiple Fronthaul functional splits. These splits are associated with different features such as CoMP and CA. Initiatives like the Telecom Infra project are testing in the lab the trade-offs between capacity, latency and synchronization requirements and the high-performance features of higher functional splits. Higher splits will allow for more features but these features are not required for all deployment scenarios. Interfaces using lower level functional splits (3GPP 1-6) will use significantly less capacity and less stringent latency something that makes the vRAN’s transport network more scalable.
This scalability can be achieved by open interfaces based in Ethernet technology and fiber-alternative technologies like point to point microwave. Ethernet microwave can not only take the vRAN to locations inaccessible to fiber but can produce significant CAPEX and OPEX savings. Recent advances in microwave technology also means that for certain deployment scenarios high capacity microwave based on millimeter and traditional microwave can be used even on higher level functional splits providing a cost-effective alternative to traditional CPRI deployments.
Not clear how well this technology will be adopted yet but the promise of a simpler backhaul with point-point wireless options make it an attractive alternative. The recent announcement is proof of the promise of these solutions: https://info.mavenir.com/pr-news/adva-bt-and-mavenir
Let’s keep an eye on this space.