What is the future goal for Open RAN?
The future goal for ORAN is for any hardware and software in the cellular network to interoperate both seamlessly and securely regardless of its originating vendor.
ORAN today may have multiple vendors, but the radio unit (RU) software comes from the same company that manufactures the antennae, while the Distribution Unit (DU) and Centralized Unit (CU) could originate from another company.
Also, as noted above, RAN traditionally has been a proprietary (closed) segment of the network. Currently, it is the last remaining portion of the network that is predominantly proprietary.
What are split options with ORAN?
ORAN is based on interoperable lower layer splits, but where best to perform this split is a complex question requiring a compromise between RU simplification, support for advanced multipoint radio frequency capabilities, and requirements of the front haul transport.
Splits have been assigned numbers to assist in comparing the many available options. The higher number assignments represent splits that reside lower in the protocol stack, with less functionality deployed below the RU split.
Lower layer splits are centered in the protocol stack below the Medium Access Control (MAC) layer. Options for this include a location between the MAC and Physical (PHY) layers (Split 6), within the PHY layer (Split 7), and between the PHY layer and RF functionality (Split 8).
What is a virtualized RAN (vRAN)?
The disaggregation of hardware and software for the radio access network is known as vRAN. It involves the separation of traditional hardware from the software that operates the base stations, RU, DU, and CU.
Because it evolves hardware-driven functions into virtualized (or software-based) functions, vRAN is often seen as the next step in cellular network evolution—most notably in the advancement of 5G. That said, a vRAN can still be a proprietary solution requiring both hardware and software to be provided by the same vendor (which maintains vendor lock-in).
Below is a high-level illustration of a virtualized proprietary (closed) RAN: