Software-Defined Exchange for the Virtualized WiFi Network towards Future Mobile Cloud Services

This paper proposes a software-defined exchange (SDX) scheme for the federation of the virtualized WiFi system and the VNode system, a deeply programmable network virtualization platform, to facilitate Mobile Cloud Computing (MCC) over SDN. We envision the future MCC services, where QoE of the services is further enhanced by SDN's capabilities such as auto-scaling of the network resources to accommodate fluctuated traffic, and seamless migration of server-side programs to the network edge. Towards the future MCC, a cross-domain federated virtual network (slice) across wireless and wired domains is needed, while individual slice operations and policies in each domain should be maintained for supporting the diversity of virtualization technologies. Though some SDX schemes have been proposed in the literature, they implicitly assume inter-connection of virtualized wired domains and it is difficult to apply them to virtualized wireless domains. To address this issue, in this paper we focus on the federation between the VNode and the virtualized WiFi platform through the Slice Exchange Point (SEP) framework as a case study, and specifically propose the WiFi portal function that enables the SEP to inter-connect a VNode slice and a WiFi slice by translation between the common slice description defined by SEP and the WiFi-specific one. This paper shows the design of the WiFi portal and its implementation on the virtualized WiFi prototype system. We build an experimental system using the two virtualized WiFi base stations and four VNode nodes, and demonstrate a wide-area federated slice can be dynamically built in 238 seconds without any manual operation.