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Taleb T.,NEC Europe | Ksentini A.,University of Rennes 1
MSWiM 2013 - Proceedings of the 16th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems | Year: 2013

Building mobile networks, on demand and in an elastic manner, represents a vital solution for mobile operators to cope with the modest Average Revenues per User (ARPU), on one hand, and the ever-increasing mobile data traffic, on the other hand. An important research problem towards this vision of carrier cloud pertains to the development of adequate technologies and methods for the on-demand and dynamic provision of a decentralized and elastic mobile network as a cloud service over a distributed network of cloud-computing data centers, forming a federated cloud. An efficient mobile cloud cannot be built without efficient algorithms for the placement of network functions over this federated cloud. In this vein, this paper argues the need for avoiding or minimizing the frequency of mobility gateway relocations and discusses how this gateway relocation avoidance can be reflected in an efficient network function placement algorithm for the realization of mobile cloud. The proposed scheme is evaluated through computer simulations and encouraging results are obtained. © 2013 ACM.


Taleb T.,NEC Europe | Ksentini A.,University of Rennes 1
IEEE International Conference on Communications | Year: 2012

Due to their numerous advantages, current trends show a growing number of femtocell deployments. However, femtocells would become less attractive to the general consumers if they cannot keep up with the service quality that the macro cellular network should provide. Given the fact that the quality of mobile services provided at femtocells depends largely on the level of congestion on the backhaul link, this paper introduces a flow mobility/handover admission control method that makes decisions on layer-three handovers from macro network to femtocell network and/or on entire or partial flow mobility between the two networks based on predicted QoS taking into account metrics such as network load/congestion indications and based on predicted QoE metrics. The performance of the proposed admission control is evaluated via simulations and encouraging results are obtained. © 2012 IEEE.


Ksentini A.,University of Rennes 1 | Taleb T.,NEC Europe
IEEE Transactions on Broadcasting | Year: 2013

Associating DVB-T2 and Scalable Video Coding (SVC) constitutes an efficient way for broadcasting added-value video services, such as HDTV and 3D TV, to end-users. The ultimate objective of this new approach of broadcasting video services is to ensure high Quality of Experience (QoE) for end users. Whilst Quality of Service (QoS) is the collective effect of performance that determines the degree of satisfaction of a user of a service, QoE reflects more accurately the user experience, as it is based on human perception when evaluating the video quality. Maximizing user QoE is thus becoming a crucial requirement when deploying new broadcast platforms for the provisioning of high quality video services. The contributions of this paper are two-fold. At first, we introduce a reference-less QoE measurement tool dedicated to SVC coding. Based on a learning function, this tool is able to learn the non-linear relationship between parameters affecting video quality and perceived user QoE. According to several experiments carried out using this tool, we demonstrate that decoding all SVC layers is not always efficient to achieve high user QoE, mostly when SVC enhanced layers experience packet losses. For the sake of maintaining a good QoE, it is worthwhile withdrawing enhanced layers experiencing packet losses and not displaying them to end-users. Based on this observation, we propose a QoE-Based Adaptive SVC Decoding (QoE-BASD) algorithm that assists a video receiver to select the appropriate SVC layers for video decoding in order to maximize QoE. We evaluate the performance of the proposed solution: (i) analytically, by using discrete Markov Chains to model the proposed solution; and (ii) via OPNET-based computer simulations. The obtained results are encouraging, and illustrate the gain achieved by QoE-BASD when compared to the conventional approach. © 1963-12012 IEEE.


Taleb T.,NEC Europe | Ksentini A.,University of Rennes 1
IEEE International Conference on Communications | Year: 2013

Emerging social media applications are expected to cause severe congestion to mobile networks, both mobile core network and mobile radio access network. These social media applications are characterized by the fact that they involve sessions with frequently and dynamically updated content, shared with a potential number of mobile users sharing the same location, or being dispersed over a wide area. A method to dynamically identify such applications/sessions and initiate multicast based delivery of the relevant content is proposed. The performance of the proposed method is evaluated through computer simulations, taking Twitter as an example. Encouraging results are obtained. © 2013 IEEE.


Taleb T.,NEC Europe | Ksentini A.,University of Rennes 1
IEEE International Conference on Communications | Year: 2013

Existing gateway selection mechanisms base their selection on gateway load and/or geographical proximity of users to the gateways. In this paper, we mainly argue the need for other metrics to improve the gateway selection mechanisms in distributed mobile networks. We therefore propose considering the end-to-end connection and the service/application type as two important additional metrics in the selection of data anchor gateways in the context of the Evolved Packet System (EPS). To enable this, two solution variants are proposed. Simulations were also conducted to evaluate the performance of the proposed solutions and encouraging results are obtained. © 2013 IEEE.


Taleb T.,NEC Europe | Ksentini A.,University of Rennes 1
IEEE Network | Year: 2013

This article introduces the Follow-Me Cloud concept and proposes its framework. The proposed framework is aimed at smooth migration of all or only a required portion of an ongoing IP service between a data center and user equipment of a 3GPP mobile network to another optimal DC with no service disruption. The service migration and continuity is supported by replacing IP addressing with service identification. Indeed, an FMC service/application is identified, upon establishment, by a session/service ID, dynamically changing along with the service being delivered over the session; it consists of a unique identifier of UE within the 3GPP mobile network, an identifier of the cloud service, and dynamically changing characteristics of the cloud service. Service migration in FMC is triggered by change in the IP address of the UE due to a change of data anchor gateway in the mobile network, in turn due to UE mobility and/or for load balancing. An optimal DC is then selected based on the features of the new data anchor gateway. Smooth service migration and continuity are supported thanks to logic installed at UE and DCs that maps features of IP flows to the session/service ID. © 1986-2012 IEEE.


Ksentini A.,University of Rennes1 | Hadjadj-Aoul Y.,University of Rennes1 | Taleb T.,NEC Europe
IEEE Network | Year: 2012

One of the most important problems posed by cellular-based machine type communications is congestion. Congestion concerns all the parts of the network, both the radio and the core network impacting both the user data plane and the control plane. In this article, we address the problem of congestion in machine type communications. We propose a congestion-aware admission control solution that selectively rejects signaling messages from MTC devices at the radio access network following a probability that is set based on a proportional integrative derivative controller reflecting the congestion level of a relevant core network node. We evaluate the performance of our proposed solution using computer simulations. The obtained results are encouraging. In fact, we succeed in reducing the amount of signaling while maintaining a target utilization ratio of resources in the core network. © 1986-2012 IEEE.


Nadembega A.,University of Montréal | Hafid A.,University of Montréal | Taleb T.,NEC Europe
IEEE International Conference on Communications | Year: 2012

Along with the recent and ongoing advances in the wireless and mobile access technologies, a wide plethora of mobile multimedia services have emerged. Ensuring an acceptable level of Quality of Service (QoS) is a crucial requirement to allow users enjoy these mobile multimedia services. One means to ensure QoS is to minimize the frequency and magnitude of fluctuations in the mobile multimedia streaming rates during the multimedia service and while users are on the move. For this purpose, there is need for tools to predict a user's long-term movement. In this vein, this paper proposes a Path Prediction Model (PPM) to predict a user's movement path. PPM is based on historical movement trace, current movement data and spatial conceptual maps; it assumes a priori knowledge of the destination. At each road intersection, the probability of selecting the next road segment is evaluated, based on historical data, towards the destination. These probabilities are computed via (a) filtering historical data according to the day of the week (e.g., weekend, holiday) and the time of the day; and (b) applying conditional probability rules taking into account the path used between the origin of movement, current position, and the destination. Simulations are conducted using real-life data to evaluate the performance of the proposed model. Encouraging results are obtained in terms of average prediction accuracy and mitigation of the impact of learning period and the remaining distance to reach the destination on the path prediction performance. © 2012 IEEE.


Nadembega A.,University of Montréal | Taleb T.,NEC Europe | Hafid A.,University of Montréal
IEEE International Conference on Communications | Year: 2012

Mobile Wireless Network technology has enabled the development of increasingly diverse applications and devices resulting in an exponential growth in usage and services. One challenge in mobility management is the movement prediction. Prediction of the user's longer-term movement (e.g., 10 min in advance) with reasonable accuracy is very important to a broad range of services. To cope with this challenge, this paper proposes a new method to estimate a user's future destination, called Destination Prediction Model (DPM). This method combines two types of approaches: one based on the use of filtered historical movement pattern and another based on contextual knowledge; both approaches use spatial conceptual maps. The filter is based on the day and the time of the day to increase accuracy. The current movement direction, that takes into account the recent data, is used by the proposed method to reduce historical and contextual knowledge mistakes. Simulations are conducted using real-life data to evaluate the performance of the proposed model. For subjects with low predictability degree, DPM reaches an average prediction accuracy of 79%; it reaches 91% for subjects with high predictability and 86% for other subjects. Simulation results also indicate that DPM significantly reduces the impact of learning period and the remaining distance to reach the destination on prediction performance. In the future, we plan to extend our research work by proposing a full Path Prediction Model (PPM) based on the Destination Prediction Model (DPM). © 2012 IEEE.


Nasser N.,Alfaisal University | Karim L.,University of Guelph | Taleb T.,NEC Europe
IEEE Transactions on Wireless Communications | Year: 2013

Scheduling different types of packets, such as real-time and non-real-time data packets, at sensor nodes with resource constraints in Wireless Sensor Networks (WSN) is of vital importance to reduce sensors' energy consumptions and end-to-end data transmission delays. Most of the existing packet-scheduling mechanisms of WSN use First Come First Served (FCFS), non-preemptive priority and preemptive priority scheduling algorithms. These algorithms incur a high processing overhead and long end-to-end data transmission delay due to the FCFS concept, starvation of high priority real-time data packets due to the transmission of a large data packet in non-preemptive priority scheduling, starvation of non-real-time data packets due to the probable continuous arrival of real-time data in preemptive priority scheduling, and improper allocation of data packets to queues in multilevel queue scheduling algorithms. Moreover, these algorithms are not dynamic to the changing requirements of WSN applications since their scheduling policies are predetermined. In this paper, we propose a Dynamic Multilevel Priority (DMP) packet scheduling scheme. In the proposed scheme, each node, except those at the last level of the virtual hierarchy in the zone-based topology of WSN, has three levels of priority queues. Real-time packets are placed into the highest-priority queue and can preempt data packets in other queues. Non-real-time packets are placed into two other queues based on a certain threshold of their estimated processing time. Leaf nodes have two queues for real-time and non-real-time data packets since they do not receive data from other nodes and thus, reduce end-to-end delay. We evaluate the performance of the proposed DMP packet scheduling scheme through simulations for real-time and non-real-time data. Simulation results illustrate that the DMP packet scheduling scheme outperforms conventional schemes in terms of average data waiting time and end-to-end delay. © 2002-2012 IEEE.

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