Software Defined 5G Mobile Backhaul

Abstract

A major challenge of future mobile networks is providing the needed elastic scaling to the increased traffic demand, number of users and applications with acceptable cost. Another challenge is suitability for numerous communications applications while curbing unwanted traffic on the air interface and the mobile devices. This paper proposes a vision of how these challenges can be met by applying the concept of Software Defined Networking (SDN) to mobile networks. We also discuss the needed migration path that minimizes unnecessary replacement investments. While we have verified some key parts of the vision with experiments, we realize that the effectiveness of the proposed approach depends on the adoption of SDN technology for other purposes so that mass production of SDN switches leads to significant economies of scale. The paper shows how we can model mobile networks using SDN concepts and migrate the 3GPP mobile architecture to SDN. The resulting control plane of the mobile architecture consists of a group of SDN applications starting from the base stations i.e., virtual eNodeBs, Backhaul transport, Mobility management, Access, Caching, Monitoring, and Services delivery. The data plane consists of simplified access points and SDN and Carrier Grade Ethernet switches. Our experiments are based on using OpenFlow as the interface between the planes.

Towards flexbile SDN-based management for cloud-based mobile networks

“…These are virtual OF switches (1 per site) that consitute a virtual overlay network on top of the BBUs (Figure 2b) as an additional layer in the protocol stack of the BBUs, above their IP interfaces towards the core. The role of these RRH-related OF switches resembles that of those co-located with the eNodeBs in the works [5,13] presented above. Additionally, an aggregator switch is also needed before the server node.…”

“…The idea of applying SDN in C-RAN setups has been discussed in the literature, and it is a potential solution to the increased flexibility requirements for 5G mobile networks [10] [11] [12]. In [13], the authors investigate the requirements in terms of elasticity and scalability of 5G mobile networks, and propose the use of SDN to ensure such elasticity on the backhaul network. They claim that using SDN in mobile networks is the natural evolution of the control and data plane separation that is being pursued by the 3 rd Generation Partnership Project (3GPP) with Long Term Evolution (LTE).…”

Will SDN Be Part of 5G?

“…While transforming LTE architecture into SDN's 3 plane model, EPC control nodes, e.g., MME, HSS, and PCRF are usually suggested to be implemented as application plane modules as shown in Table V [4], [56], [81], [109], [110], [112], [113], [115]. Similar ideas are evident into the evolving 5G system's architecture from 3GPP [2], where mobility management and policy control functions are connected to other new functions, such as, authentication, application management, etc.…”

“…Popular Ideas References Key Issues/Solutions/Ideas [4], [56] 1-S/P-GW split in C/U planes, [2], [109]-[111] Application 1-EPC control nodes [81], [109] 2-S/P-GW CP part is used as application layer as applications/functions [112], [113] 3-CP/UP split is economically optimal [114]. [110], [115] 4-Centralized control may create bottlenecks [116] Control layer 1-Distributed control [113], [117] 1-Delay limit determines cluster size [118], [119] 2-Handover between clusters [118] 3-Optimal controller placement [111], [120] 4-Local controllers for time-critical tasks [3], [121] 2-Hierarchical control [81], [122] 1-Different controller for core, RAN, orchestration, etc.…”

Software-Defined Wireless Transport Networks for Flexible Mobile Backhaul in 5G Systems

“…The work in [18] presents and OpenFlow-based packet switched backhaul where simple Ethernet switches are used, moving the intelligence associated to the mobile network to external applications interacting with a centralized SDN controller.…”