In this paper, we define a flexible, adaptable, and programmable architecture for 5G mobile networks, taking into consideration the requirements, KPIs, and the current gaps in the literature, based on three design fundamentals: (i) split of user and control plane, (ii) service-based architecture within the core network (in line with recent industry and standard consensus), and (iii) fully flexible support of E2E slicing via per-domain and cross-domain optimisation, devising inter-slice control and management functions, and refining the behavioural models via experiment-driven optimisation. The proposed architecture model further facilitates the realisation of slices providing specific functionality, such as network resilience, security functions, and network elasticity. The proposed architecture consists of four different layers identified as network layer, controller layer, management and orchestration layer, and service layer. A key contribution of this paper is the definition of the role of each layer, the relationship between layers, and the identification of the required internal modules within each of the layers. In particular, the proposed architecture extends the reference architectures proposed in the Standards Developing Organisations like 3GPP and ETSI, by building on these while addressing several gaps identified within the corresponding baseline models. We additionally present findings, the design guidelines, and evaluation studies on a selected set of key concepts identified to enable flexible cloudification of the protocol stack, adaptive network slicing, and inter-slice control and management.

To meet quality of service requirements on the uplink of future cellular networks, we need to exploit intercell interference among users eligible for cooperation. Cloud Radio Access Network (C-RAN) architecture is particularly favorable to realize cooperation between users in neighboring cells, since signal detection is realized in the same processing unit. The novel technology of Software Defined Networking (SDN) increases the flexibility of network optimization and scalability of computational resources. We propose a C-RAN based architecture and a practical scheme of realizing uplink joint processing in critical scenarios where strong interference would affect cell-edge users. We consider characteristics of a real network and novel technological solutions necessary for reliable transmission over the radio access network. The central idea is to split the physical layer processing between Remote Radio Heads (RRHs) and the central processing unit only for selected users in enabling cooperation and maintaining affordable fronthaul transport infrastructure. In practice, the joint detection for selected few co-channel users would simplify the required multiuser channel estimation while improving overall performance and cell-edge users' quality-of-service (QoS).

Abstract-Software defined networking (SDN) is growing rapidly in telecommunications due to its capability to efficiently manage end-to-end networks by decoupling control plane and data plane. The scalability and flexibility can bring benefits to network management and maintenance. However, it has yet to happen for wireless networks since there is a lack of practical solutions for migrating Radio Access Networks (RAN) to software defined wireless networks. Here, we design a wireless SDN controller based on OpenDayLight (ODL). We show how our framework can support typical use case and Self-Optimized Network algorithm. The design is highly flexible and can be leveraged for future wireless networks such as C-RAN and 5G.

Software Defined Networking (SDN) has attracted tremendous interest in the telecommunication industry due to its ability to abstract, manage and dynamically re-configure endto-end networks from a centralized controller. Though SDN is considered to be a suitable candidate for various use cases in mobile networks, none of the work so far has discussed its advantages and actual realization for Train-to-Wayside Communication System (TWC). In this paper, for the first time, the architecture and use cases of SDN controlled mobile backhauling framework for TWC is proposed. We discuss how our proposed architecture can efficiently handle mobility management and also provide dynamic quality-of-service (QoS) for different services on board. As a first step, a software prototype is developed using industrial standard OpenDayLight SDN controller to have our architecture evaluated. Since the automotive sector is being considered to be an important driver for 5G network, our SDN based mobile backhauling solution can be positioned in 5G where SDN plays an important role.

Coordination between neighboring cells is intended to be implemented in future mobile networks, since it promises significant performance gains. Despite low-latency cooperation made possible by Cloud Radio Access Networks (C-RAN), practical feasibility and improvements brought to a real system were still to be evaluated. We define in this paper an architecture based on the abstraction and scalability provided by Software Defined Networking (SDN) enabling multi-cell coordination both on the uplink and downlink. We also evaluate gains offered by the proposed coordination algorithms under practical conditions. The described proof-of-concept platform shows not only why multi-cell cooperation is useful, but also how to make it happen.