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In this paper a new method for analyzing complex queueing networks is proposed: the isolation method. As an example, we study packet switching networks with finite buffer size at each node. [ABSTRACT FROM AUTHOR]

iA tandem queueing system with blocking due to finite waiting room is considered. Maximum throughput is studied by an approximation for several eases. The service time can depend on the number of customers; intermediate arrivals can also be allowed. Some special models with two stations in sequence and blocking are examined. These models are used for the performance evaluation of computer systems. In particular, the maximum throughput for a virtual memory operating system and for a node-to-node protocol in a computer network are obtained. [ABSTRACT FROM AUTHOR]

The article focuses on the INTERMIP project, a research project undertaken by the French National Telecommunications Research Network. The INTERMIP project aims to define and develop the traffic handling and dimensioning rules required to optimize traffic engineering in the new multimedia Internet Protocol (IP) networks such as integrated services (IntServ) and the differentiated services (DiffServ). Categories of the project are discussed.

Discusses a research project conducted by the French National Telecommunications Research Network that defined and developed the traffic handling and dimensioning rules needed to optimize traffic engineering or data flows in Internet Protocol (IP) networks as of May 2002. IP network services being defined by the project; Tasks involved in characterizing the different traffic categories to be found in a multimedia network.

Reports that the French Telecommunications Regulator has issued an official statement on wireless local area network (LAN) radio frequencies usage in France. Presentation of the official statement; Deployment of wireless LAN access points in public locations; Importance of telecommunications services to the public.

Cites the key findings of the National Telecommunications Research Network/Multiservice Internet Protocol Network Evaluation and Traffic Engineering research project. Recommendations on rules for multiservice Internet Protocol network traffic engineering; Implications on the telecommunications sector.

The number of devices connected through the Internet of Things (IoT) will significantly grow in the next few years while security of their interconnections is going to be a major challenge. For many devices in IoT scenarios, the necessary resources to send and receive bytes are extremely high and when such devices are powered with battery the amount of exchanged bytes directly impacts their life time. As a result, compression of existing protocols is a widely accepted technique to make IoT benefit from the protocols developed over the last decades. This paper presents ESP Header Compression (EHC), a framework that enables compression of packets protected with Encapsulating Security Payload (ESP). EHC is composed of EHC Rules, targeting the compression of a specific field and organized according to EHC Strategies. Further, the paper presents Diet-ESP, an EHC Strategy that highly reduces the networking overhead of ESP packets to address the IoT security and bandwidth requirements. Diet-ESP results in sending fewer bytes which in turn reduces the number of required radio frames and thus battery consumption. The measurements showed that sending 10 byte application data on IEEE 802.15.4 radio networks secured with the standard ESP requires sending an additional frame. This results into a 95% energy overhead compared to the unprotected data, while Diet-ESP results only in a 3% overhead compared to unprotected data. This small overhead is achievable with some compressions being performed within the ESP stack which requires altering the same. Nevertheless, Diet-ESP remains fully security compliant to ESP and performs better than any other compression framework as far as ESP is considered. [ABSTRACT FROM AUTHOR]

Radio Frequency IDentification (RFID) technology offers a new way of automating the identification and storing of information in RFID tags. The emerging opportunities for the use of RFID technology in human centric applications like monitoring and indoor guidance systems indicate how important this topic is in term of privacy. Holding privacy issues from the early stages of RFID data collection helps to master the data view before translating it into business events and storing it in databases. An RFID middleware is the entity that sits between tag readers and database applications. It is in charge of collecting, filtering and aggregating the requested events from heterogeneous RFID environments. Thus, the system, at this point, is likely to suffer from parameter manipulation and eavesdropping, raising privacy concerns. In this paper, we propose an access and privacy controller module that adds a security level to the RFID middleware standardized by the EPCglobal consortium. We provide a privacy policy-driven model using some enhanced contextual concepts of the extended Role Based Access Control model, namely the purpose, the accuracy and the consent principles. We also use the provisional context to model security rules whose activation depends on the history of previously performed actions. To show the feasibility of our privacy enforcement model, we first provide a proof-of-concept prototype integrated into the middleware of the Fosstrak platform, then evaluate the performance of the integrated module in terms of execution time. [ABSTRACT FROM AUTHOR]

Wireless Mesh Networks (WMNs) consist of a high-density of hundreds to thousands of mesh routers (MRs) deployed in corporate offices and university campuses. The main purpose of this deployment is to meet user demands for high bandwidth, mobility, and reliability. However, our recent consideration of such networks revealed that they are rarely used at their peak capacity besides the fact that the entire MRS remains active continuously. Thus, during lower traffic periods the energy consumption is the same as in busy hours, while it would be possible to save a large amount of power. Green networking has recently been proposed; consist of rethink how networks are constructed and operated so that not only the cost and performance are taken into consideration but also their energy consumption and carbon footprint. In this paper, we draw attention that a large part of idle MRs results in considerable energy losses. Thousands of WMNs worldwide jointly aggravate this problem, while raising serious worry about the energy wastage that will happen in the future. In response to this problem, we first propose an optimal approach called Optimal Energy Efficiency Management Design (OEEMD) by formulating the problem as a Mixed Integer Linear Program (MILP) model to investigate the power consumption in WMN. As this problem is known to be NP-hard, we then propose an efficient heuristic algorithm called Green Energy Efficiency Management Design (GEEMD) for wireless mesh networks. GEEMD uses a sleep mechanism to power on/off underutilized MRs, based on the traffic load and solar energy generation. For the performance evaluation, we used OEEMD and GEEMD to study the performance of WMN deployment scenario in the university and campus area of Tlemcen city in Algeria over dynamic traffic profiles. Illustrative numerical examples show that, with suitable design parameters, we can efficiently reduce energy consumption in WMN without significantly impacting the network performance. [ABSTRACT FROM AUTHOR]

Recently, operators have resorted to femtocell networks to enhance indoor coverage and increase system capacity. Nevertheless, to successfully deploy such solution, efficient resource-allocation algorithms and interference mitigation techniques should be deployed. The new applications delivered by operators require large amounts of network bandwidth. Although, some customers may want to pay more in exchange for a better quality of service (QoS), some others need fewer resources and can be charged accordingly. Hence, we consider an orthogonal frequency-division multiple-access (OFDMA) femtocell network serving both QoS-constrained high-priority (HP) and best-effort (BE) users. Our objective is to satisfy a maximum number of HP users while serving BE users as well as possible. This multiobjective optimization problem is NP-hard. For this aim, we propose in this paper a new resource-allocation and admission control algorithm, which is called QoS-based femtocell resource allocation (Q-FCRA), based on clustering and taking into account QoS requirements. We show through extensive network simulations that our proposal outperforms two state-of-the-art schemes [centralized-dynamic frequency planning (C-DFP) and distributed random access (DRA)] and our previous proposal, i.e., femtocell resource allocation (FCRA), in both low- and high-density networks. The results concern the throughput satisfaction rate, spectrum spatial reuse, the rate of rejected users, fairness, and computation and convergence time. [ABSTRACT FROM PUBLISHER]

Virtualization is a key technology to enable cloud computing. It enhances resource availability and offers high flexibility and cost effectiveness. However, the driver domain-based model for network I/O virtualization exhibit poor networking performance. In this paper, we evaluate the networking performance of VMs based on Xen. The I/O channel transferring packets between the driver domain and the VMs is shown to be the bottleneck. To overcome this limitation, we proposed a packet aggregation-based mechanism to transfer packets from the driver domain to the VM. Experimental performance evaluation showed that our proposal allows the VMs throughput to scale up at line rates. Furthermore, we studied the impact of the aggregation on the packets delay. For this purpose, we proposed a system modeling based on queuing theory. The proposed model allowed us to dynamically tune the aggregation mechanism to achieve the best tradeoff between the packets delay and throughput. The proposed I/O virtualization model henceforth satisfies the infrastructure providers to offer cloud computing services. [ABSTRACT FROM AUTHOR]

Abstract: The performance of a wireless local area network (WLAN) depends on the channel assignments among interfering access points (APs). Due to the limited number of non-overlapping channels, severe interference scenarios may arise if no appropriated spectrum planning is employed. In our study we focus on WLANs scenarios where APs may belong to different administrative domains, which is actually a very common situation in dense urban deployments. In such cases the use of centralized algorithms is not feasible and the already proposed distributed methods does not guarantee optimal channel assignment. In this paper, therefore, we formalize the channel allocation as a distributed constraint optimization problem (DCOP) and propose a new distributed channel assignment algorithm named DCAA-O, which can find the optimal solution to the channel assignment problem for a group of APs. A suboptimal strategy denoted DCAA-S is also investigated, which aims at reducing the number of control messages to be exchanged between APs, while still achieving a suboptimal solution which is very close to the optimal one. The simulation results show that the proposed algorithms are able to outperform the best known techniques both in terms of solution quality and number of exchanged messages. [Copyright &y& Elsevier]

We present a simulation platform for access selection algorithms in heterogeneous wireless networks, called "ABCDecision". The simulator implements the different parts of an Always Best Connected (ABC) system, including Access Technology Selector (ATS), Radio Access Networks (RANs), and users. After describing the architecture of the simulator, we show an overview of the existing decision algorithms for access selection. Then we propose a new selection algorithm in heterogeneous networks and we run a set of simulations to evaluate the performance of the proposed algorithm in comparison with the existing ones. The performance results, in terms of the occupancy rate, show that our algorithm achieves a load balancing distribution between networks by taking into consideration the capacities of the available cells. [ABSTRACT FROM AUTHOR]

Abstract: Capacity planning of IP-based networks is a difficult task. Ideally, in order to estimate the maximum amount of traffic that can be carried by the network, without violating QoS requirements such as end-to-end delay and packet loss, it is necessary to determine the queue length distribution of the network nodes under different traffic conditions. When per-flow guarantees are required (e.g., VoIP traffic), it is also necessary to determine the impact of the queue behavior on the performance of individual flows. Analytical models for queue length distribution are available only for relatively simple traffic patterns. This paper proposes a generic method for building a fuzzy predictor for modeling the behavior of a DiffServ node with multiple queues. The method combines nonlinear programming (NLP) and simulation to build a fuzzy predictor capable of determining the performance of a DiffServ node subjected to both per-flow and aggregated performance guarantees. This approach does not require deriving an analytical model, and can be applied to any type of traffic. In this paper, we employ the fuzzy approach to model the behavior of a multi-queue node where (aggregated ON–OFF) VoIP traffic and (self-similar) data traffic compete for the network resources. [Copyright &y& Elsevier]

In this paper, we address the Wireless Sensor Network (WSN) deployment issue. We assume that the observed area is characterized by the geographical irregularity of the sensed events. Formally, we consider that each point in the deployment area is associated a differentiated detection probability threshold, which must be satisfied by our deployment method. Our resulting WSN deployment problem is formulated as a Multi-Objectives Optimization problem, which seeks to reduce the gap between the generated events detection probabilities and the required thresholds while minimizing the number of deployed sensors. To overcome the computational complexity of an exact resolution, we propose an original pseudo-random approach based on the Tabu Search heuristic. Simulations show that our proposal achieves better performances than several other approaches proposed in the literature. In the last part of this paper, we generalize the deployment problem by including the wireless communication network connectivity constraint. Thus, we extend our proposal to ensure that the resulting WSN topology is connected even if a sensor communication range takes small values. [ABSTRACT FROM AUTHOR]

Packet-based optical access ring is becoming a promising solution in metropolitan networks. Its performance depends mainly on how optical resource sharing takes place among the different competing access nodes. This network architecture mission (i. e., slotted WDM ring). However, in this article we focus on the performance of asynchronous transmission-based networks with variable packet sizes. We investigate the fairness issue that is likely to arise between upstream and downstream nodes sharing a common data channel. Furthermore, we show that sharing the channel's available bandwidth fairly but arbitrarily between access nodes, as in slotted WDM rings, does not resolve the fairness problem in asynchronous systems. In this regard, we exhibit the inherent limitations of the token bucket access rate-based algorithm once applied to asynchrous transmission bus-based network. To alleviate the aforementioned problem, we devise a new strategy called Traffic Control Architecture Using Remote Descriptors (TCARD). The proposed solution is based on a preventive mechanism to grant access to the shared resource. As illustrated in the article, the proposed solution alleviates performance degradation and resource underutilization while achieving fairness among bus nodes. [ABSTRACT FROM AUTHOR]

Introduces a series of articles on quality of service support for wireless communication networks.

This article proposes a service level agreement applied to the optical domain (O-SLA), network is expected to be the near- and long-term network technology thanks, among other things, to the great bandwidth capacity offered by optical devices. After an exposition of the rationale behind an optical SLA, parameters that could be included in this O-SLA, as well as their values for four classes of services, are proposed. Different client (wavelength or subwavelength and service types (from leased wavelength to band-width on demand) are distinguished when necessary. The last part of this article presents issues related to the provisioning of services emanating from this O-SLA. [ABSTRACT FROM AUTHOR]

The deployment of QoS over the Internet may achieve protocols for the negotiation of service levels, as well as mechanisms for the end-to-end realization of service level agreements. Such general-purpose protocols include Common Open Policy Service (COPS) for policy specification within a domain. This article proposes an extension of the COPS protocol for intra- and interdomain service level negotiation. The proposed protocol is known as COPS-SLS. This allows the configuration of domain policies regarding service levels, and the automatic negotiation of service levels within the domain policies [ABSTRACT FROM PUBLISHER]

Presents a study which proposed an extension of common open policy service (COPS) protocol for intradomain and interdomain service level negotiation for the Internet. Overview of quality of service and service level specification (SLS) requirements; Elements of policy-based networking management system; Information about the operation of COPS-SLS; Analysis of the characteristics of COPS-SLS.

Nowadays, wireless networks are largely deployed, and the number of smart phones has boomed, as well as data transfer via mobile phones. This has resulted in the emergence of multihoming, which allows the user to enjoy the best access for each application. The context of our work is mobile multihomed terminals in a heterogeneous environment. We propose a solution for interdomain mobility management with end-to-end service continuity of communication. For this purpose, we combine a multihoming protocol (SHIM6), which ensures a seamless network change, with the IMS architecture, which allows the establishment of multimedia sessions with quality of service. Our proposal enables a mobile terminal to change its access network seamlessly, without any application disruption. To achieve this, we implement a P-SIP inside the terminal to manage the signaling procedures. The proposed scheme can manage the interdomain mobility of a terminal in two modes: reactive and proactive. A testbed allows us to show the feasibility of our approach and the obtained gain by reducing considerably the handover delay and thus, the data loss. [ABSTRACT FROM PUBLISHER]

This article presents a service-centric orchestration protocol for self-interested autonomic management systems that supports the coalition formation process in largescale collaborative and competitive environments. It supports environments in which coalition formations are carried out targeting multiple service requests at the same time, and in which the autonomic management systems compete to work in the most appropriate coalition. The protocol exploits the benefits of social networking in favor of manageability and scalability. Its performance is analyzed taking into account crucial aspects of self-organizing systems such as stability and convergence to optimal coalition formation results. [ABSTRACT FROM PUBLISHER]