5G Midhaul Networks
Network operators need open standard-based transport xHaul networks, such as Fronthaul, Midhaul, and Backhaul. This allows a broader and safer provider supply chain for mobile operators and wholesalers.
An open, standard-based xHaul network creates a more profitable wholesale market. With xHaul networks, a change is prompted where retailers do not have to leave their dark fiber to migrate to standard-based packet network services. This is very similar to current Backhaul services.
What is Midhaul?
At radio 4G distributed (D-RAN) access networks, the baseband unit (BBU) is located at the base of a macro cell tower. In a radio access 4G (C-RAN) centralized or virtualized architecture, the BBU is physically located at a telephone switching facility or a remote data center.
Fronthaul refers to a network that connects remote radio heads (RRHs) to BBUs, several kilometers away. Meanwhile, Midhaul interconnects the new BBU 5G disaggregated BBU.
5G RAN
5G RAN will evolve from traditional BBU architecture and remote radio heads (RRHs) used for 4G networks. This evolution will be to a distributed unit (DU), centralized unit (CU), and active antenna unit (AAU) architecture.
When a BBU is disaggregated, some of its traditional functions are at the DU. The remaining sublayers such as PDCP, SDAP, and RRC will make up the CU. 5G radio systems will adopt an AAU architecture, where RRH systems and antennas will be integrated under one single device. Thus, DU and CU may be virtualized and hosted in RAN computer resources located at different network points.
From the perspective of a virtualized RAN, specific hardware accelerators will be necessary. Thus, they will assist the x86 CPU inside workload virtualization of DU and CU. Likewise, accelerators will be required to comply with IEEE 1588 Packet Timing Protocol (PTP) and Synchronous Ethernet (SyncE) requirements. In the same way, physical layer one processing, such as a forward error correction (FEC), will take place.
5G radio system disaggregation will result in new Midhaul interphase, which will be based on packets connecting DUs and CUs on a new 3GPP F1 interphase.
Across the F1 interphase, latency and jitter requirements are not as strict as those of O-RAN 7.2x Fronthaul. For this reason, useful F1 load can be transported on a variety of packet-based transport mechanisms.
A new 3GPP E1 interphase will connect CU-UP and CU-CP connections. Thus, transport Midhaul networks can be deployed using a variety of topologies, such as star, mesh, and ring, based upon operator requirements.
The future of network and Midhaul
Midhaul is compatible with a wide variety of Ethernet interphase rates (10GbE, 25 GbE, or 50GbE with greater capacity DU systems).
Additionally, Midhaul network transport performance is expected to support reaches of up to 100 km with a latency of 5 milliseconds or less.
Open standards and specifications will facilitate the creation of open, standard-based Midhaul networks. Likewise, they will add multiple benefits to the system.
At NGIN Services we offer network solutions to help your company take a step towards the future. Contact us and learn more about Midhaul networks and the multiple benefits they can draw for your company. Request more information about our services.
