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Dynamically Reconfigurable Optical-Wireless Backhaul/Fronthaul with Cognitive Control Plane for Small Cells and Cloud-RANs

Periodic Reporting for period 2 - 5G-XHaul (Dynamically Reconfigurable Optical-Wireless Backhaul/Fronthaul with Cognitive Control Plane for Small Cells and Cloud-RANs)

Reporting period: 2016-07-01 to 2018-06-30

To address the high bandwidth and low latency requirements of 5G networks, 5G-XHaul proposed converged optical and wireless networks technologies that form a flexible transport infrastructure supporting both backhaul and fronthaul services managed by a single unified Software Defined Networking (SDN)-based control plane. An unified solution capable of transporting backhaul and fronthaul services simultaneously has been developed.

5G-XHaul demonstrated in the city of Bristol on June 27th 2018 a converged optical and wireless network solution offering both fronthaul (FH) and backhaul BH) services. This converged infrastructure is controlled by the flexible and scalable 5G-XHaul control plane. The combination of these technologies make the overall solution able to jointly support end-user and operational services.

To enable these novel concepts, the 5G-XHaul consortium developed:
1. A novel data plane architecture integrating together a variety of heterogeneous wireless and optical technologies and the required data plane interfaces across domains.
2. High throughput and low-cost wireless BH technologies including mmWave and Sub-6 technologies.
3. A hybrid optical transport network integrating active and passive technologies. These include: the Time Shared Optical Network, supporting elastic and fine bandwidth allocation, and Passive optical networks adopting wavelength division multiplexing for increased capacity.
4. A flexible and scalable control plane relying on the software defined networking architectural model that controls both wireless and optical technologies.
5G-XHaul has managed to fully deliver on the promise of a converged fronthaul and backhaul architecture, combining wireless and optical SDN technologies, which has been demonstrated in operational conditions in a city-wide testbed. We successfully integrated and demonstrated the complete converged front- and backhaul service scenario over a single transport infrastructure capable of delivering the CPRI data for the massive MIMO RRH and two Ethernet backhaul services for the wireless SDN at the same time. The performance of each subsystem has been thoroughly analysed in this demonstration measuring the round-trip delays and throughput for both BH and FH traffic. The correct reception of the 16-QAM constellation, while concurrently transporting Ethernet traffic, validates the ability of the 5G-XHaul architecture to jointly transport BH and FH services.

We believe the results achieved in 5G-XHaul are a key stepping-stone towards the practical deployment of high capacity 5G networks.
5G-XHaul developed a custom functional split that offloads antenna processing into the antenna array, in order to have the transport requirements imposed by a Massive MIMO array scale with the number of spatial streams, instead of scaling with the number of antenna elements. TSON was extended in the following ways: i) Ethernet backhaul flows were defined in terms of the outer VLAN tag, used to define a label switched path (in line with the 5G-XHaul networking model), ii) TSON was extended to be able to support CPRI traffic, thus providing joint FH and BH capabilities, and iii) Time stamping support was added to TSON to better support CPRI flows. All these features were demonstrated in operational conditions in the final deployment in Bristol.

The on-demand establishment of connectivity services across multiple technology domains (NITOS and i2CAT), has been experimentally demonstrated in this reporting period. We have demonstrated how such connections can be set up in just a few seconds, therefore enabling autonomous network operations in the future. This relates to the service creation time reduction expected in 5G.

5G-XHaul demonstrated a fully functioning joint operation of CPRI based C-RAN and Ethernet through the 5G-XHaul infrastructure. C-RAN traffic was transported through the optical segment of the 5G-XHaul infrastructure, including both TSON and WDM-PONThe final demonstrator in Bristol featured two types of RANs connected to the 5G-XHaul transport, namely Wi-Fi, and C-RAN LTE using Massive MIMO. This deployment therefore provides proof of the flexibility of the 5G-XHaul to operate in a RAN agnostic way, while accommodating different types of RANs. Dynamic point-to-multipoint (p2mp) mmWave capabilities have been experimentally demonstrated using the Typhoon devices developed by BWT. In addition, the p2mp capability has been integrated with an SDN agent

To date, the Capital EXpenditures (CAPEX) and OPerational EXpenditures (OPEX) required to deploy and manage networks in these scenarios are not manageable by mobile operators with existing technologies, while the latter are pushed to their limits and will not be able to deliver the required services and QoS in the near future. By introducing a consolidated network architecture, and delivering network management algorithms maximizing the efficiency of network resources, 5G-XHaul will also contribute to CAPEX/OPEX reductions of future transport networks infrastructures, to the benefit of both operators/providers and the subscribers (better QoE, lower tariffs). In addition, the 5G-XHaul architecture will allow for the enhancement of existing stakeholders’ roles and/or the introduction of new players/stakeholders in the telecom industry. Finally, the intense research activity taking place in the context of the project, will ensure further funding opportunities (both for the research community and the private sector) and significant impact on standardization (for the benefit of the industry and the technology itself). The technical work of the project has been complemented with work on the economic assessment of 5G-XHaul solution/technologies deployment. For this purpose, 5G-XHaul in deliverable D6.4 presents a fully parameterised Techno-economic analysis Tool to assist 5G-XHaul Operators