There were nearly four dozen demos of O-RAN (Open Radio Access Network) implementations at MWC Barcelona 2022, roughly half of them live on-site. These demos strongly suggest that O-RAN equipment is now moving from the conceptual stage to the successful implementation stage, and deployment.
After prior-year cancellations and delays because of COVID-19 restrictions, the big Barcelona party known as Mobile World Congress (MWC) was a live event this year. Buried among the shiny new smartphones and other personal wireless gewgaws on display, were the latest infrastructure advances that will help wireless carriers deliver the promise of 5G.
RANs (radio access networks) are the key network components that convey RF signals between the ether and the copper and fiber-optic cables that deliver the audio, video, and data streams to telecom data centers so that they can be transported to their destination.
These data streams support myriad applications beyond the obvious audio and video calls and include cloud gaming, teleconferencing, and the looming metaverse. The radio standards that define the multiplicity of 5G RF bands and access protocols complicate RAN design, which has driven the wireless industry to develop open standards to help drain some of the implementation difficulty out of the mix while boosting performance and reducing the cost of RAN implementations.
The O-RAN (Open RAN) Alliance, founded in 2018 by an international group of carriers including AT&T, China Mobile, Deutsche Telekom, NTT DOCOMO and Orange — is the organization working to define global working standards for RANs. This year’s MWC Barcelona provided a snapshot of how that work is progressing.
In the four years since its founding, the O-RAN Alliance has grown to more than 300 members including well-known carriers such as Dish Network, KDDI, Rakuten Mobile, Telefonica, Verizon, and Vodafone. Beyond mobile operators, the membership list includes hardware and software vendors such as Intel, Nvidia, Qualcomm and Xilinx; research organizations; and academic institutions.
The organization conducted 22 demos of O-RAN implementations based on the organization’s standards at MWC Barcelona 2022, with an additional 24 demos viewable online in the organization’s Virtual Exhibition Hall. These demos strongly suggest that O-RAN equipment is now moving from the conceptual stage to the successful implementation stage, and deployment.
For the 4G and 4G LTE generations, RANs were tightly coupled, systems that combined the radio unit (RU) and the baseband unit (BBU) in one proprietary unit. To meet the O-RAN Alliance’s goals for 5G RANs (open, intelligent, virtualized, and fully Interoperable) the Alliance’s O-RAN standards define a decoupled system that separates RUs from the BBUs and splits the BBU into a DU (distributed unit) and a CU (centralized unit). The O-RAN Alliance’s DU handles real-time and scheduling functions while the CU handles non-real-time functions. Consequently, a CU can usually be implemented with a processor-based design while a DU requires more performance than a CPU can deliver.
One O-RAN Alliance demo at MWC Barcelona 2022 that illustrated a full, working O-RAN implementation, from Wistron NeWeb Corp. (WNC), was a 5G End-to-End (E2E) O-RAN system. This system streams 4K video via a sub-6 GHz, 5G RF connection to a client laptop at 945 Mbps. WNC’s E2E (End to End) O-RAN demo includes CPE (customer premise equipment), O-RU (open radio unit), O-DU (open distributed unit), and O-CU (open centralized unit) designs developed in-house by WNC. Because they’re real-time units, WNC based its O-RU and O-DU designs using programmable logic. In particular, the O-DU is based on the recently announced Intel N6000 Acceleration Development Platform, formerly called Arrow Creek.
In this demo, WNC’s O-CU and O-DU are plugged into a COTS server based on an Intel Xeon-D (Ice Lake-D) CPU. Both the O-CU and O-DU units support the O-RAN Alliance’s O1 interface for configuration, performance, and fault management services as defined by the 5G O-RAN’s Service Management and Orchestration (SMO) architecture. The SMO specification provides the automated control and orchestration required for automating 5G operator networks. According to WNC, this system has already been deployed in a private 5G network belonging to a large telecom operator in Taiwan, and WNC claims it’s ready for commercial carrier use.
