TNC 2014 Abstract: Software-Defined Networking in Heterogeneous Radio Access Networks
Hao Yu · 2014
Radio-over-Fiber (RoF) technologies expedite the formation of heterogeneous radio access networks (HRANs), where different radio frequencies are transmitted over the same the fiber connection to the remote antenna to provide different wireless access, e.g. 4G (LTE, WiMAX), 3G (WCDMA, TD-SCDMA, CDMA2000), and WLAN (Wi-Fi). This allows operators to deploy a cost-efficient access network. Handover of mobile devices among different access technologies is inevitable. A seamless handover mechanism is thus required so that the access shift is transparent to the mobile applications and the users. The concept of Software-Defined Networking (SDN), which has been evolving for many years, aims at decoupling the control and data planes, centralizing network intelligence, and abstracting the underlying network infrastructure from the applications. In other words, SDN minimizes the dependency on hardware and protocols to maximize the innovation on network management and applications. By using protocol-controllable network equipment, operators can develop and use customized application programming interfaces (APIs) to send information to the controller. The controller will then translate the instructions into low-level protocols, such as OpenFlow [1], and modify the behavior of network devices, e.g. flow table, forwarding scheme, etc. In such a mechanism, various kinds of APIs or applications can be developed, to implement different capabilities of network. Centered on the controller, APIs can be categorized into northbound, southbound, westbound, and eastbound APIs. OpenFlow is one of the southbound APIs that interface directly with devices and has created many possibilities for network applications.