The stringent requirements made by an ever-increasing data traffic are pushing mobile operators to bring innovative network solutions for sustainable network growth. A critical requirement is to elastically scale network resources with minimized cost and on demand. Such network dimensioning aspects can be satisfied by the Network Function Virtualization (NFV) paradigm, which provides Network as a Service (NaaS) using network functions implemented and deployed in software over the cloud. Implementing and deploying virtualized Evolved Packet Core (vEPC) is a prioritized objective of operators and vendors towards a 5G network, enabling flexible network management while maximizing its availability based on virtualization aspects. However, current design and deployment initiatives for 5G do not consider that their adoption by operators will need to pass through a co-existence period with the existing legacy network. Considering the contribution of network virtualization aspects, along with standardized interworking procedures between 3GPP EPC networks, the vEPC can be exploited on demand to effectively address the explosion of traffic going through the legacy EPC network, without requiring radical changes over the currently deployed infrastructure. This paper presents a NFV-based traffic offloading framework architecture using vEPC, aiming to enable on-demand traffic offloading when the legacy EPC network capacity is reaching a utilization threshold. In the proposed framework architecture, we present vEPC modes aiming to satisfy different offloading aspects while taking into consideration efficient resource usage. Available traffic monitoring modes are introduced and the required procedures for instantiating a vEPC on demand are specified, while considering virtualized gateway allocation and session establishment for mobile terminals.
Conference: 2015 IEEE Conference on Standards for Communications and Networking (CSCN) in Tokyo, Japan