An Insight Into Software Defined Wireless Networks Christian Niephaus, George Ghinea Brunel University London, United Kingdom christian.niephaus@brunel.ac.uk george.ghinea@brunel.ac.uk Osianoh Glenn Aliu, Senka Hadzic, Mathias Kretschmer Fraunhofer FOKUS Sankt Augustin, Germany osianoh.glenn.aliu@fokus.fraunhofer.de senka.hadzic@fokus-extern.fraunhofer.de mathias.kretschmer@fokus.fraunhofer.de Abstract—The flexibility of future wireless networks architec- tures is aimed at allowing more innovation, reducing complexity and improving service offerings. Software Defined Networking (SDN) has been identified as an enabler for this adoption. In order to grasp a better understanding of the challenges faced as well as the potential uses cases, we identify the need for flexible software defined wireless network, its applications and challenges and propose an architectural framework. I. I NTRODUCTION Network operators are forced to embrace new services and revenue opportunities, but not necessarily new technologies that require overhauling their physical network. It is thus pertinent to give operators the freedom and flexibility to innovate and create new service offerings by providing them with a more flexible network architecture. This is the main driver for the evolution of today’s communication networks towards being software based. SDN was initially designed for infrastructure based wired networks. However, due to its huge potential, various use cases and testbeds for its application to wireless networks have been discussed. Having a programmable wireless network will be of benefit to developers, researchers and operators looking to use and provide applications of SDN in the wireless domain. We acknowledge that SDN may mean different things to different network operators and service providers from different technological domains. In the context of this paper, our reference to SDN is in the context of a network framework that allows network operators to intelligently manage and control their network in a flexible and simplified way using software based tools (high-level languages and APIs). This is achieved by a logical separation of application, control and data planes as well as abstraction of the open interfaces between them. SDN advocates a new way of thinking network architectures in order to make them flexible and open for innovation. In principle, it proposes for design of future network architectures be based on the following principles [1], [2], [3], [4]: 1) Physical separation of data plane from control plane with open interfaces between them. 2) Protocol independent forwarding (rules-action model). 3) Logically centralized network control and management. 4) Programmable software based networks. 5) Network Virtualization. 6) Simplified generic forwarding devices. 7) Technology abstraction. The aim of this paper is to first introduce Software Defined Wireless Network (SDWN) as a guide for further research that will be done in the wireless domain. Second, to present a logical flow of describing the need for flexible, software based wireless networks, challenges and benefits as well as an architecture for implementation. The rest of this paper is organized as follows: Section II gives a summary of current efforts in SDWN for Wireless Local Area Network (WLAN) and mobile cellular networks. In section III, the use cases and challenges peculiar for wireless networks are described. In Section IV, we present our proposed framework with description of modules in each plane. We conclude by giving pointers for future work required for adoption of SDWN in Sections V and VI. II. LITERATURE REVIEW:SOFTWARE DEFINED WIRELESS NETWORKS There has been extensive work and surveys on SDN in wired networks, networking in data centers and OpenFlow specifications in particular ([5], [6] and [7]). However, it has also been acknowledged recently that the principles of SDN also benefit wireless networks. One of the pioneering papers on making wireless networks software defined in accordance with OpenFlow specification was presented by Yap et al. in [4]. OpenFlow Wireless builds on top of OpenFlow and serves to separate control and data, decouples mobility from the physical network, and is able to slice/virtualize the network using FlowVisor. Using this virtualization, multiple service providers can control the underlying infrastructure. Thus service providers can handle mobility, authentication and billing for their users, regardless of the network they are connected with. The authors also present Openroads in [8] to serve as an enabler for future innovation in wireless networks. The long term objective is to trigger virtual network operators and virtual service providers whose service delivery will be independent of the underlying