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Two proposals are presented in this study in an attempt to solve the problem of network selection, which are based on fuzzy logic techniques and methods of decision making. The first proposal uses a combination of the fuzzy method with two MADM (Multiple Attribute Decision Making) methods, the AHP (Analytic Hierarchy Process) and the GRA (Grey Relational Analysis), whereas the latter uses only the...
When a feedback controller is implemented in a networked embedded system, the computations and communications induce delays and jitter, which may destabilize the control loop. The majority of previous work on analysis of control loops with time-varying delays has focused on output (actuation) jitter. In many embedded systems, input (sampling) jitter is also an issue. In this paper, we analyze the...
WiMAX (Worldwide Interoperability for Microwave Access) is emerging as one of the most promising technology for wireless communication network in metropolitan areas today. It is designed to provide different services such as voice, data and video with different type of QoS(Quality of Service). A scheduling scheme plays a very important role to achieve the QoS requirement. There are scheduling algorithms...
Monitoring of Quality of Service (QoS) in high-speed Internet infrastructure is a challenging task. However, precise assessments must take into account the fact that the requirements for the given quality level are service-dependent. Backbone QoS monitoring and analysis requires processing of large amount of the data and knowledge of which kind of application the traffic belongs to. To overcome the...
Mobile voice-assisted services are currently experiencing strong growth. However, occasionally low real-time quality of service within mobile networks could have significant negative impact on quality of experience of users interacting with automated voice services. Latency may grow to unacceptable levels and speech recognition and synthesis might suffer. We present a methodology of mitigating such...
A scalable photonic sampled analog-to-digital conversion (ADC) is presented utilizing four-wave mixing processes to multicast and sample a signal. By expanding the architecture to multiple parallel gates, the effective sampling rate is increased.
Enhanced Distributed Channel Access (EDCA) is a mandatory part of the IEEE 802.11e standard which provides Medium Access Control (MAC) layer solution for Quality of Service (QoS) provisioning in Wireless Local Area Networks (WLANs). It is a contention based protocol which prioritizes channel access to QoS traffic using four Access Categories (ACs). In this paper, we introduce the performance evaluation...
This work presents a study of the effect of router buffer size on the subjective quality experienced by players of online games, which is a service with very tight real-time requirements. Quality estimators for other real-time services like e.g. VoIP were developed years ago, and they are commonly used when planning a new telephony system. They mainly use delay and loss as KPI (Key Performance Indicators)...
The proliferation of mobile Internet services for smartphones makes it more necessary than ever to use measurement tools in mobile devices to monitor their connectivity performance. In this paper we introduce TestelDroid, a software tool for Android devices which provides advanced monitoring functionalities for analyzing multimedia services and applications specifically designed for smartphones. The...
In this paper, we propose QoE assessment model for video streaming service such as IPTV and VoD using QoS parameters in wired-wireless network. Existing perceptual quality assessment models are unsuitable for experienced quality assessment of a streaming service which passed through the IP-based network because they only take account of the characteristic of used codec and bit rate. However, QoS parameters...
With the growth of different types of Internet traffic, there is a compelling need to provide better quality of service especially over the increasing number of wireless networks. Expected Transmission Count (ETX) is a high throughput route selection metric developed for routing protocols used in Wireless Mesh Networks (WMNs). Using the minimum hop count to find the shortest path has been shown to...
When network induced delays are considered in the event-triggered control literature, they are typically delays from the plant to the controller and a tight bound on the admissible delays is usually imposed based on the analysis of inter-event time. In [19], a dynamic output feedback based event-triggered control scheme is introduced for stabilization of input feed-forward output feedback passive...
In this paper a new Active Queue Management (AQM) strategy based on Nonlinear Generalized Minimum Variance (NGMV) control is proposed for TCP/AQM networks. The NGMV control is a model free method which only requires output of the system. Cost function of this method involves weighted output error and weighted control signal terms. The NGMV controller is implemented in order to minimize the cost function...
Networked control systems (NCS) are distributed control system in which sensors, actuators and controllers are physically separated and connected through communication networks. NCS represent the evolution of networked control architectures providing greater modularity and control decentralization, ease maintenance and diagnosis and lower cost of implementation. A recent trend in this research topic...
In this work, a network simulator for power line communications based in the Homeplug-AV technology is presented. The simulator implements both the physical and the MAC layers, along with an in-home power line channel generator, which makes it very useful in a wide variety of network optimization procedures. To the authors' knowledge, performance evaluation of the MAC layer of Homeplug-AV by means...
Recently, network coding (NC) has been popularly applied to wireless networks in order to improve scarce wireless capacity. In wireless LANs, NC can be applied to packet retransmission in which multiple packets can be equivalently transmitted by a single retransmission trial at base station (BS). In this paper, retransmission based on NC cooperates with IEEE 802.11e EDCA. In EDCA, when network load...
The performance of cognitive radio is determined by the spectrum occupancy, which is correlated in space, time and frequency. In this paper, the theory of random fields is applied to model the spatially correlated spectrum occupancy. The entire cognitive radio networks are modeled as a plenary grid or a straight line. Two dimensional and one dimensional Ising models are applied to model the joint...
Virtualization based cloud computing hosts networked applications in virtual machines (VMs), and provides each VM the desired degree of performance isolation using resource isolation mechanisms. Existing isolation solutions address heavily on resource proportionality such as CPU, memory and I/O bandwidth, but seldom focus on resource provisioning rate. Even the VM is allocated with adequate resources,...
VoIP service demands strong QoS support for enhanced call quality and increased user satisfaction. Deploying VoIP in opportunistic communication models like cognitive radio requires thorough analysis of the factors involved in design and implementation. The objective of this paper is to implement VoIP successfully over a cognitive radio network and maintain the call quality at an acceptable limit...
The glowworm swarm optimization algorithm is used to solve the multi-constrained QoS multicast routing problem and QoS-GSO algorithm is presented. Our test shows that the algorithm can find optimal solution quickly and has better performance than GA and ACO. Furthermore, for the larger multi-constrained QoS multicast routing problem, the QoS-GSO algorithm can also quickly obtain the correct solution,...
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