Page 131 - ITU-T Focus Group IMT-2020 Deliverables

ITU-T Focus Group IMT-2020 Deliverables 3

Figure 6.4.2-1 – 5G-Crosshaul transport network architecture

Applications running on top of the Crosshaul Control Infrastructure (XCI) are also being developed, with focus
on aspects related to network re-configuration, energy efficiency, media distribution, and mobility
management. Examples of these are applications include: 1) Resource Manager Application (RMA) for
dynamic network reconfiguration, 2) Energy Management and Monitoring Application (EMMA) for
optimisation of energy consumption by activating and deactivating network elements depending on the
context, 3) CDN Management Application (CDNMA) and the TV Broadcasting Application (TVBA) for media
distribution, and 4)Mobility Management Application (MMA) for mobility management optimization even in
the most challenging scenarios (e.g., high-speed trains).

6.4.2.4 5G-Crosshaul components and PoC

The envisioned 5G-Crosshaul transport network solution will consist of high-capacity switches and
heterogeneous transmission links (e.g., fibre or wireless optics, high-capacity copper, mmWave)
interconnecting Remote Radio Heads, 5GPoAs (e.g., macro and small cells), cloud-processing units (mini data
centres), and points-of-presence of the core networks of one or multiple service providers. This transport
network will flexibly interconnect distributed 5G radio access and core network functions, hosted on in-
network cloud nodes, through the implementation of: (i) a control infrastructure using a unified, abstract
network model for control plane integration (Crosshaul Control Infrastructure, XCI); (ii) a unified data plane
encompassing innovative high-capacity transmission technologies and novel deterministic-latency switch
architectures (Crosshaul Packet Forwarding Element, XFE).
A holistic approach for converged Fronthaul and Backhaul under common SDN/NFV-based control is targeted
through key components depicted in Figure 6.4.2-2;
– XCF: Common Frame capable of transporting the mixture of various Fronthaul and backhaul traffic
– XFE: Forwarding Element for forwarding the CrossHaul traffic in the XCF format under the XCI control
– XPU: Processing Unit for executing virtualized network functions and/or centralized access protocol
functions
– XCI: Control Infrastructure that is SDN-based and NFV-enabled for executing the orchestrator’s
resource allocation decisions
– Novel network apps on top to achieve certain KPIs or services

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