21581 - SCTE Broadband August2022 COMPLETE v1

64 Vol. 44 No. 3 - September 2022 Issue The choice of which option to use depends on the desired throughput and latency requirements of the overall network. Figure 11 gives some examples of the performance expected. Splitting network functions between CU, DU and RU requires the definition of an additional standard for interconnecting these devices. Just as the splitting of RRH and BBU functions introduced the use of the CPRI protocol, the new functional splits introduce eCPRI and F1, both based on Ethernet technology. Traditionally, the devices used to implement the network functions have been supplied by a single manufacturer. As we journey through 5G we will see additional standards that will allow interoperability between multi- vendor equipment. Initiatives such as the open radio access network (O-RAN) and the Telecom Infra Project (TIP), among others, are actively working towards this goal, with initial deployments targeted in late 2020. EXFO is an active participant in these organisations and will support test equipment for compliant devices as the market evolves. The future of 5G Not only will future 5G implementations support different network splits but they will also allow MNOs to select the best devices to implement that split from a selection of multiple vendors. 5G introduces the concept of network slicing which avoids the need to construct separate networks with different architectures to support the latency and throughout requirements of the various applications. This allows the bandwidth on the physical network to be split into numerous slices, each slice dedicated to providing a specific capability. Network virtualisation Another concept that 5G embraces is network function virtualisation (NFV). Imagine that each of the functions in a 5G network could be modeled in software and become a virtualised network function (VNF), and that these models could Figure 11: Throughout and latency characteristics of network split options Figure 12: Network slicing technical