iCIRRUS proposes an intelligent Ethernet-based fronthaul for the Radio Access Network (RAN) of 5th Generation (5G) and beyond mobile communications. The fronthaul is a core component of the cloud- or virtualized-RAN, C-RAN or vRAN, that is now seen as essential for such future mobile systems. The intelligence, enabled by the use of Ethernet and probing the resulting fronthaul network, can also enhance the operation of other, user-facing applications. In iCIRRUS, cellular-assisted device-to-device (D2D) communication is targeted, as some network functions are placed closer to users and could aid localisation, for example, as is mobile cloud computation, which again may benefit from placing functionality closer to users in the C-RAN/vRAN. Further, an aim is to examine how the intelligence gathered can be used to optimise network performance, for the fronthaul and its effect on radio performance, and for the D2D and mobile cloud operations.
The iCIRRUS project has delivered a number of testbed demonstrations that have separately verified key performance targets identified for the network architecture. It has also delivered a final, integrated showcase demonstration that combines five different fronthaul/midhaul/backhaul streams through an Ethernet time-sensitive networking aggregator with support for timing and synchronisation, together with mobile cloud/clone use cases for video transcoding/streaming and task offloading services.
Overall, the Ethernet fronthaul concept proposed in the project has been validated through the measurements that verify key performance indicators can be met, and through analysis and simulation. This evolved fronthaul, supporting a virtualised RAN will be a necessary component if future 5G deployments. By focussing on Ethernet and addressing its main challenges for the fronthaul, iCIRRUS has made a significant contribution to research and innovation in this area.
The mobile cloud/clone operations have been demonstrated in the context of a Unified Communications use case, which has strong business potential. Significant theoretical analyses have been published in the highest-raking IEEE journals clearly exposing the energy savings inherent in the mobile cloud/clone, C-RAN/vRAN and D2D proposals.
The work has influenced standards bodies through direct presentations or through indirect interactions, and is clearly aligned with the current thinking in important bodies such as 3GPP.
The work has met all of the objectives set out at the beginning of the project:
1. Energy efficiency enhancements through the C-RAN/fronthaul, mobile cloud and D2D, together with joint resource management.
2. Feasibility of the Ethernet fronthaul and convergence with fixed-access (Passive Optical Networks - PONs).
3. D2D spectral and energy efficiency reduction through use of the evolved RAN and a new signalling scheme for device discovery.
4. Spectrum and energy efficiency for the mobile cloud, particularly through task and communication offloading.