Section: New Results

Future Networks

Participants : Yassine Hadjadj-Aoul, Adlen Ksentini, Leila Ghazzai, Jean-Michel Sanner.

Mobile cloud. One of the 5G-architecture visions considers the usage of cloud to build mobile networks and help in decentralizing mobile networks on demand, elastically, and in the most cost-efficient way. This concept of carrier cloud becomes of vital importance knowing that several cloud providers are distributing their cloud/network, globally deploying more regional data centers, to meet their ever-increasing business demands. As an important enabler of the carrier cloud concept, network function virtualization (NFV) is gaining great momentum among industries. NFV aims for decoupling the software part from the hardware part of a carrier network node, traditionally referring to a dedicated hardware, single service and single-tenant box, and that is using virtual hardware abstraction. Network functions become thus a mere code, runnable on a particular, preferably any, operating system and on top of a dedicated hardware platform. The ultimate objective is to run network functions as software in standard virtual machines (VMs) on top of a virtualization platform in a general-purpose multi-service multi-tenant node (e.g., Carrier Grade Blade Server) put into the cloud. In [31] , we presented and detailed the Follow Me Cloud (FMC) concept, whereby mobile services hosted in federated clouds follow mobile users as they move and according to their needs. We then provided in [55] a detailed analytical model based on continuous time Markov chain which considers to evaluate the performance of FMC in terms of service migration cost and QoS gain for user. An efficient mobile cloud cannot be built without efficient algorithms for the placement of NFV over this federated cloud. In this vein, in [57] we argued the need for avoiding or minimizing the frequency of mobility gateway (S-GW) relocations and discussed how this gateway relocation avoidance can be reflected in an efficient network function placement algorithm for the realization of mobile cloud. The problem was modeled by an Integer Linear Problem and proved to be NP hard. Therefore, two heuristics were proposed for the creation of a NFV S-GW instance in the cloud.

SDN. We started an activity on Software Defined Networking (SDN), a recent idea proposed to handle network management problems. SDN are becoming an important issue with the ever-increasing network complexity. They are proposed as an alternative to the current architecture of the Internet, which cannot meet the supported services requirements such as Quality of Service/Experience (Qos/QoE), security and energy consumption. We particularly address the scalability issue by proposing a hierarchical controller-based architecture handling the whole control chain.