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The evaluation of performance and quality of service needs the modeling of wireless networks. Among the different models usually considered, the hexagonal network is the most popular. However, it requires extensive numerical computations. The Poisson network model, for which the base stations (BS) locations form a stochastic spatial Poisson process, allows to consider a non constant distance between...
In this paper, we consider a coordinated multipoint (CoMP) dynamic cell selection (DCS) scheme in order to improve performances of sleeping cell users. According to this DCS, packets for user equipments (UEs) in a sleeping cell are randomly forwarded to the potential active base stations (BSs) by the packet serving gateway (PSG) and UEs in the sleeping cell dynamically select these active BSs to be...
Current electrical grid is facing increased penetration of intermittent energy resources, in particular wind and solar energy. Fast variability of the power supply due to renewable energy resources can be balanced out using different energy storage systems or shifting the loads. Efficiently managing this fast flexibility requires two-way data exchange between a controller and sensors/meters via communication...
Traffic in wireless sensor networks (WSN) exhibits a many-to-one pattern in which multiple source nodes send sensing data to a single sink node. Since bandwidth, processor and memory are highly constrained in WSN, packet loss is common when a great deal of traffic rushes to sink. The system must provide differentiated service to individual traffic classes. In this paper, a pre-emptive multiple queue...
P2P live streaming system is one of the most popular Internet applications which develop rapidly in the past decade. However, some common problems, such as long startup delay and unsmooth playback, seriously restrict user's experience on live streaming. In this paper, we propose a novel but simple scheme, namely guarantee mechanism of contingency resource (GMCR), which can improve the quality of service...
Communications in organizations have been one of the most important issues. To run the business processes, the company needs communication between units and customers. We provide a framework which can be used by network designers in an organization. The outcome of the framework is value for three QoS parameters: delay, loss and availability. The organizations business processes are used as a basis...
In this paper, a load-based joint call admission control (LJCAC) scheme for heterogeneous wireless networks is proposed. The LJCAC scheme aims to achieving the load balance in heterogeneous networks as well as guaranteeing the quality of service (QoS) satisfaction. We also develop the analytical models to calculate the connection-level performance of the proposed LJCAC scheme in two typical heterogeneous...
This paper discusses a concept of predicting interactions between measurable (technical) parameters of telecommunications network - QoS (Quality of Service) and QoE (Quality of Experience) of the video under realistic triple play network conditions using IPTV (Internet Protocol TV). Here is represented a simulation method using OPNET as simulation tool that includes a complete scenario of IPTV channels...
A mathematical representation of patient or device is presented by a number of variables which are defined to represent the inputs, outputs and a set of equations describing the interaction of these variables. This paper proposes a global methodology for modeling and simulation medical systems and human body, in order to analyze the performance and the quality of services of all system components...
Radio-over-fiber (RoF) technology can effectively improve reliability and quality of service (QoS) of railway communication systems. This paper studies the coverage efficiency of ROF in heavy haul railway. Coverage efficiency is determined by calculating the area power consumption of cell according to combined path loss and shadowing model. The value of the length of remote antenna unit (RAU) cells...
Improving Quality of Service (QoS) in wireless networks is important and necessary for mobile users. We have previously proposed Comfort Route (CR) Navigation, which navigates users to their destinations using high QoS communication areas, such as Wi-Fi APs, rather than the geographical Shortest Route (SR). In this paper, we employ an analytical model to estimate the CR gain in a theoretical manner...
For content delivery in Peer-to-Peer (P2P) video streaming systems there are two main approaches: push-based and pull-based. In P2P Video-on-Demand (VoD) systems, neighbor peers might watch the same video with very large differences in viewing point; thus using push-based approach is not sufficient for these systems. Also, with using pull-based approach, peers need large buffers to achieve better...
Service Oriented Architectures and service-centric models arose in the last years as a standard de-facto in IT enterprises for offering practically any kind of services to users world-wide. In particular Cloud-based models provide means for realizing and distributing, including infrastructures, hardware and software platforms and services. Even if at the moment Service-centric models and technologies...
In this study, the discrete-time performance of BLUE algorithms under bursty and correlated traffics is analyzed using two-state Markov-modulated Bernoulli arrival process (BLUE-MMBP-2). A two-dimensional discrete-time Markov chain is used to model the BLUE algorithm for two traffic classes, in which each dimension corresponds to a traffic class and the parameters of that traffic class. The MMBP is...
Internet of Things (IoT) aims to enable the interconnection of a large number of smart devices (things) using a combination of networks and computing technologies. But an influx of interconnected things makes a greater demand on the underlying communication networks and affects the quality of service (QoS). This paper investigates into the QoS of delay sensitive things and the corresponding traffic...
Long Term Evolution (LTE) is the most recent evolution of mobile phone standards; it has been proposed to provide higher throughput and better spectral efficiency. However with the increasing of services applications supported by each device in LTE networks, the resources sharing function is one of the key challenging issues. In this context, Logical Channel Prioritization (LCP) is referred. In this...
Access Point (AP) selection in WiFi hotspots is driven by stations and it is based on the measured strongest RSSI (Received Signal Strength Indicator) level: any station connects to the AP that provides the higher physical data rate. Although simple and effective in low crowded scenarios with low-medium traffic load, this strategy performs inefficiently when the number of mobile users is high and...
The fast-developing services in internet pose challenges to the efficient transmission of various types of data, so an effective packet scheduling scheme is needed to meet the Qos constraints of heterogeneous services. In this article, the priority-queuing model is used to study the performances of various strategies based on delay sensitivity and packets length. And the non-preemptive short-packet-first...
Delay Tolerant Networks (DTN) has been proposed to provide communication between nodes where they are intermittently connected. In this situation, a new routing approach, store-carry-forward, is used to deliver data between source and destination. Even though long delay is acceptable in DTN, however some applications occasionally require predetermined bounded delay. To meet this requirement, some...
This paper aims at systematically analyzing the pricing schemes in data center network. The interaction between a monopolistic operator and customers in the network is modeled as Stackelberg game. In this model, both homogeneous- and heterogeneous-customer scenarios are analyzed. In homogeneous customer case, a special scenario is that only a single customer exists in the network. In this scenario,...
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