Molka Gharbaoui

An advanced smart management system for electric vehicle recharge

Recent studies about climate change are mandating a drastic reduction of green house gas (GHG) emissions. Solutions include the utilization of renewable energy sources (e.g., wind, solar energy) and the increased utilization of hybrid and electric vehicles (EVs). In this scenario ICT can play a significant role by fostering the smart utilization of current energy and transportation infrastructures (smart grid and smart cities). This paper presents a new ICT infrastructure to enable the intelligent exploitation of distributed energy resources in order to minimize the EV charging times while optimizing the efficiency of the electrical infrastructure. The proposed system is based on a distributed communication infrastructure (both wired and wireless) aimed at collecting/emitting bidirectional energy dispatching opportunities for electric vehicles. The envisaged system seamlessly interconnects emerging self-organizing wireless technologies (i.e., VANETs and Wireless Mesh Networks), with legacy wired communication technologies, to guarantee a fast rollout of the EV charging service with minimum investments in communication infrastructures. The performance of the proposed solution is evaluated in terms of its sustainability by analyzing the quality of the charging service as perceived by the users, and the capability of the charging infrastructure to meet the charging requests in a timely manner.

Anycast-based optimizations for inter-data-center interconnections [Invited]

The cloud service delivery model is driving the data center (DC) architectural model towards a fully virtualized infrastructure acting as geographically distributed pools of shared resources, dynamically allocated to different services. Such a scenario calls for the anycast routing of virtual machine (VM) migration requests in order to select the destination server where the VMs will be migrated by taking into account the actual load of DC interconnections while addressing VM data transfer requirements. To this purpose, a management platform is presented that enables the dynamic connectivity setup between DCs without a priori indication of the destination server, according to the anycast principle. Specifically, data path allocation policies are proposed to select a proper inter-DC network path, and accordingly a destination server, to allow VM migration data to experience adequate delay performance. Using a simulation approach, the policies are compared in terms of success rate of delay-constrained data path setup as well as in terms of their capability to limit migration delay.

Cross-Functional resource orchestration in optical telco clouds

With communication endpoints given by mobile user devices and by elastically provisioned virtual resources, one of the main challenge of cloud-based service provisioning is to deploy a coordinated control of both data center and network resources in order to provide adaptive data delivery services and adequate service experience to cloud users. In this regard, flexible optical networks can play a fundamental role in telco clouds to effectively address bandwidth requirements of elastic data center operations. This paper presents a cross-functional orchestration platform able to coordinate the provision of cloud-based services with multi-granular data delivery services across flexible optical network. The architectural design is described along with orchestration policies that are compared in terms of blocking ratio of service requests against the level of utilization of network links.

Preserving Confidentiality in PCE-based Multi-domain Networks

The path computation element (PCE) architecture has been proposed to effectively enable multi-domain traffic engineering (TE) in generalized multiprotocol label switching (GMPLS) networks while providing an adequate level of confidentiality among domains. However, a malicious utilization of the procedures defined within the PCE architecture might affect the confidentiality of network domain information in a multi-domain multi-carrier network scenario. This paper discusses the critical issues of the PCE architecture in terms of confidentiality. A two-step authorization scheme, named the behavior-based PCE authorization policy (BPAP), is proposed. The BPAP includes a novel add-on PCE component and a central authorization policy server to protect against confidentiality breaking. The scheme is based on the PCE protocol (PCEP) client behavior analysis and includes attack pattern detection procedures and possible partial information filtering of the reply message. The applicability of the BPAP scheme is validated in wavelength switched optical networks (WSONs) through simulations focusing on the exchange of a restricted set of available resources. Finally, a BPAP implementation is experimentally evaluated, showing the efficiency of the two-step scheme in terms of scalability, capability to limit the discovery of critical information, and reactivity to confidential attacks.

On virtualization-aware traffic engineering in OpenFlow Data Centers networks

Oversubscription of intra-Data Center network links and high volatility of VM deployments require a flexible and agile control of Data Center network infrastructures, also integrated with computing and storage resources. In this scenario, the Software-Defined Network paradigm and, specifically, the OpenFlow protocol, opens up new opportunities for the design of innovative resource management platforms that enable dynamic and fine-grain control of DC networks through traffic engineering algorithms. This paper investigates the performance of two different sets of cloud-fluent traffic engineering algorithms. Conceived to work during cloud service deployments, the main target of such algorithms is to achieve a better utilization of network resources by exploiting OpenFlow capabilities for traffic-aware deployments of Virtual Machines. The effectiveness of the proposed solutions is evaluated in terms of network link utilization against VM requests acceptance ratio through simulations and experimental tests carried out by using an ad-hoc emulator.

Cross-layer resource orchestration for cloud service delivery: A seamless SDN approach

Abstract One of the main challenges of cloud-based service provisioning is to deploy a coordinated control of both application- and network-layer resources in order to provide adaptive service data delivery and adequate user service experiences. In this work we propose a signaling framework architecture for cross-layer resource orchestration, where service awareness provided by session control is effectively combined with the flexibility of software-defined network control. Following a hands-on approach, the proposed solution takes advantage of existing and commonly deployed technologies aiming at an incremental deployment of the software-defined control mechanisms for the purpose of cross-functional service orchestration. The signaling framework is presented and validated through experimental activities carried out on a test-bed reproducing a realistic cloud-based service scenario. Results are compared against an analytical model that allows to investigate and quantify the sensitivity of the cloud-based service performance to the most relevant system parameters. The study demonstrates that a critical role is played by the limitations of the response time of real devices such as commercial routers, and highlights how orchestration functions can mitigate the effect of such limitations while addressing scalability of the overall system.

SDN controller for context-aware data delivery in dynamic service chaining

Recent advances in network control and management technologies, such as software defined networking (SDN) and network function virtualization (NFV), are expected to make the network effectively able to cope with application service requirements in a more flexible and timely manner. We argue that SDN and NFV capabilities can be exploited in Next Generation Service Overlay Networks (NGSONs) for addressing contex-aware end-to-end data delivery services with adaptive composition of middlebox services when dynamically provisioned as virtual functions. In this paper we present a Service-Oriented SDN controller that allows for the programmable provision of data delivery paths through a dynamically established sequence of virtual middlebox functions, thereby accomplishing the deployment of adaptive network service chains in NGSON. In this way, an extended set of QoS requirements can be addressed that include specifications on processing functions to be traversed by service data while taking advantages from context-awareness and self-adaptation capabilities of NGSON. A use case analyis have been carried out on an experimental testbed about the effectiveness of the proposed approach in differentiating service data processing while optimizing the use of forwarding tables in the switches.

An SDN orchestrator for resources chaining in cloud data centers

The oversubscription of intra-Data Center links and the high volatility of Virtual Machine deployments require a flexible and agile control of the Data Center network infrastructure, possibly coordinated with computing and storage resources control. In this scenario, the Software-Defined Networking paradigm opens up new opportunities to design orchestrated resources control strategies able to meet the dynamically-changing traffic demands of instantiated Virtual Machines. This paper presents the architectural design of an SDN-based orchestrator for dynamic computing and communication resources chaining, able to assure better than best effort VMs data exchanges across Cloud Data Centers. Moreover, the paper evaluates a number of different chaining strategies able to dynamically compose proper pool of resources based on their variable load. Such strategies are compared against specific management objectives using both simulations and experiments showing their effectiveness in terms of resource usage and service provisioning rate.

SDN controller for network-aware adaptive orchestration in dynamic service chaining

This paper presents an SDN orchestrator that offers adaptive path provisioning in dynamic service chaining to recover from congestion events throughout service chain paths. Moreover, the SDN orchestrator exposes a Northbound interface based on REST principles and on the Intent-Based Network Modeling Language data model that allows applications to describe their requirements for the network (including dynamic service chaining) without being concerned with low-level implementation details. Experiments in an emulated network environment have been carried out to show the feasibility of the approach and to evaluate the effectiveness of the orchestration process in terms of network resource usage and adaptation overhead.

Policies for efficient usage of an EV charging infrastructure deployed in city parking facilities

Transportation sustainability is largely being evaluated considering the effectiveness and the efficiency of public and private transportation systems and their impact on the environment. In this context, Electric Vehicles (EVs) play a key role in the reduction of greenhouse gas (GHG) emissions. The major issues of the large-scale adoption of EVs are related to their limited range and the lack of accessible charging infrastructures. An approach based on an intelligent dimensioning and management of the charging infrastructure might be a solution. In this work, practical strategies for providing efficient recharging services and improving user satisfaction (e.g., by maximizing battery charges) are compared.