Crossflow-Plus: An SDN-Enabled Cross-Layer Architecture for Wireless Networks

Abstract

To meet the ever-growing network traffic demand, the underlying communication networks need to be open and programmable. The Software Defined Networking (SDN) paradigm separates the traditional data plane and network control plane, providing the ability to design, develop and manage the communication networks in an efficient and scalable manner. SDN enables a high degree of network programmability by providing high-level abstractions of the network devices and interfaces to manipulate them. SDN has attracted significant attention in the research community that produced a large body of work on programmable data plane and control frameworks. However, the existing studies mainly focus on the wireline networks, while wireless networks have received only limited attention. Wireless traffic has significantly increased during the last couple of decades. Expansion of wireless communication networks is setback by limited usable spectrum, varying channel conditions, and signal fading. Envisioning to support re-configuration of wireless communication networks, fast dynamic reconfiguration of radio devices, and robust network programmability is necessitated. While network programmability is motivated by the SDN paradigm, Software Defined Radio provides a platform to perform various signal processing functions in software rather than hardware. However, to the best of our knowledge, there does not exist a framework to dynamically program wireless devices across all levels of the protocol stack. Accordingly, in this project, we build the foundations of a fully programmable SDN-enabled framework that can achieve this goal. The proposed framework leverages the existing SDN approaches for programmable data planes as well as the Software-Defined Radio paradigm. In particular, we propose several key extensions to the SDN packet processing pipeline that enable different per-flow behaviors at the physical layer. The contributions of this thesis include: (i) a set of different physical layer profiles are presented as abstractions to the SDN application developer which is used to set different Physical layer parameters for different traffic flow type; (ii) extensions of SDN protocols (such as OpenFlow) to provide an abstraction for various physical layer profiles; (iii) a proof-of-concept implementation and a set of use cases that demonstrate the benefits of our approach. We also perform an extensive experimental study to evaluate the performance gains that can be achieved by using fully programmable wireless devices.