Resource Management in a Hierarchically Controlled Multi-domain Wireless/Optical Integrated Fronthaul and Backhaul Network Jorge Baranda * , Jos´ e N´ u˜ nez-Mart´ ınez * , I˜ naki Pascual * , Josep Mangues-Bafalluy * , Arturo Mayoral * , Ramon Casellas * , Ricard Vilalta * , Ricardo Mart´ ınez * , Ra´ ul Mu˜ noz * , Josep X.Salvat † , Andres Garcia-Saavedra † , Xi Li † , Jakub Kocur ‡ * Centre Tecnol` ogic de Telecomunicacions de Catalunya (CTTC/CERCA) - Castelldefels (Barcelona, Spain), † NEC Labs Europe - Heidelberg (Germany), ‡ Core Network Dynamics GmbH - Berlin (Germany) Abstract—This demo presents an end-to-end hierarchical con- trol of a multi-domain multi-technology integrated fronthaul and backhaul network where a parent controller coordinates the operation of a wireless and optical child controllers managing real wireless and optical data plane resources. The services offered by this hierarchical control infrastructure are accessed through the offered REST-based northbound API by the resource management application (RMA), which is able to determine the appropriate network resource allocation based on the requested traffic profiles and the position of the different mobile entities deployed in the network. Interestingly, the same REST-based API is used between the parent and child controllers inside the control infrastructure, allowing recursive and scalable deployments. The RMA manages fronthaul and backhaul traffic generated by a flexible mobile network deployment featuring user equipments, a remote radio head, a baseband unit, an eNodeB, and an EPC. I. I NTRODUCTION 5G networks will feature a variety of Radio Access Net- work (RAN) functional splits with diverse requirements. In general, current deployments use different transport networks and interfaces for fronthaul (e.g., CPRI) and backhaul traffic. However, the trend towards packet-based fronthaul fosters a unified transport network to fulfill the requirements of all RAN splits (including regular backhaul traffic). Furthermore, the envisaged deployment scenarios for 5G networks usually entails a variety of transport technologies that, ideally, should be managed homogeneously. 5G-Crosshaul project [1] designs such an integrated fronthaul and backhaul network under the control of what is referred to as the 5G-Crosshaul Control Infrastructure (XCI) [1]. This demonstration presents a hierarchical XCI enabling End-to-End (E2E) orchestration of resources across multi- domain multi-technology transport networks. On top of this XCI, network management applications, such as the Resource Management Application (RMA), are in charge of efficiently using the underlying network resources. Examples of the application of the concept of hierarchical control of SDN networks can be found in data centers [2]. In the context of transport networks, an example by the same authors of this demonstration can be found in [3]. Additionally, we are presenting a real use case, namely a flexible mobile network infrastructure featuring different functional splits. A Remote Radio Head (RRH), a Baseband Unit (BBU), and an eNodeB (eNB) generate the fronthaul and backhaul traffic flows that are managed by the hierarchical XCI to eventually reach the Evolved Packet Core (EPC). II. SYSTEM ARCHITECTURE Figure 1 presents the demo system architecture including all the elements defined in the 5G-Crosshaul transport network solution [1]. Our main goal is to demonstrate how hierarchical SDN principles are used to manage heterogeneous transport networks to fulfill the 5G requirements stated previously. Data Plane and Control Plane elements come from two testbeds lo- cated at the CTTC premises (Barcelona), while the Application plane element is located at NEC premises (Heidelberg). A. Data Plane The data plane combines several domains using different transport technologies. The mmWave/Wi-Fi transport network represents the wireless edge packet-switched domain of the network. Wireless transport nodes feature several wireless Gigabit interfaces based on mmWave (IEEE 802.11ad) and Wi-Fi (IEEE 802.11ac) technologies. The wireless edge in- frastructure, due to its distributed computing capabilities, also deploys all the softwarized mobile access entities (RRH, BBU, eNB) and the user equipments (UEs) of the OpenEPC plat- form [4], where each entity runs in a different virtual machine (VM). The Multi-layer optical transport network represents the core transport domain featuring two layers, namely 1) a packet service on top of 2) a wavelength-switched domain (i.e., WDM), which features an all-optical mesh network with two colorless Reconfigurable Optical Add/Drop Multiplexer (ROADM) nodes and two Optical Cross-Connect (OXC) nodes interconnected with five bidirectional optical links using a total of 610Km of optical fiber. The softwarized EPC entity [4] runs in different VMs placed in a datacenter infrastructure connected to this domain. B. Control Plane We follow the hierarchical XCI approach designed in 5G- Crosshaul [1], where each domain is controlled through its own technology-aware controller. On top of this hierarchy, we find the E2E SDN Transport Orchestrator based on the IETF Application-Based Network Operations (ABNO) archi- tecture (acting as parent ABNO, or pABNO). The pABNO supports hierarchical deployments with arbitrary depth lever- aging thanks to its unified Southbound/Northbound Interface