3,060 research outputs found
Design and implementation of a differentiated service based qos model for real-time interactive traffic on constrained bandwidth ip networks
In this thesis work, a QoS model for real-time interactive traffic on a real
network with constrained bandwidth and real-time traffic has been proposed. The
model supports tight guarantees of QoS to real-time interactive traffic without
over provisioning of bandwidth. A dynamic scheduling model which is adaptive to
input data rate of traffic has been proposed. In this model, A Differentiated
Service (DiffServ) based approach is proposed for QoS provisioning. The packets
are classified and distributed among finite number of queues with limited
buffer based on different priorities and total available bandwidth. The model
proposes a mechanism to derive the weighted service rates and queue length
distribution so as to meet the requirement of low packet loss and delay for
real time interactive traffic in the QoS engineered network. An adaptive
queuing strategy is proposed so that minimum bandwidth in used for real time
traffic. This ensures maximizing availability to best effort traffic. The model
assumes constrained bandwidth without having to over provision the network
resources and thus keeping the cost low. A modified version suitable for
testing on a real network is also presented. Experimental verification of these
in a test bed network in a laboratory as well as on a real network has been
carried out. The results of the QoS provisioning model for different sources of
real-time traffic such as video conferencing equipment, robotic surveillance
camera has also been shown. The thesis also introduces a real-time Variable Bit
Rate (VBR) traffic tuning parameter for controlling the service of VBR traffic
to give better and fair performance to rest of the traffic
Effective Capacity in Wireless Networks: A Comprehensive Survey
Low latency applications, such as multimedia communications, autonomous
vehicles, and Tactile Internet are the emerging applications for
next-generation wireless networks, such as 5th generation (5G) mobile networks.
Existing physical-layer channel models, however, do not explicitly consider
quality-of-service (QoS) aware related parameters under specific delay
constraints. To investigate the performance of low-latency applications in
future networks, a new mathematical framework is needed. Effective capacity
(EC), which is a link-layer channel model with QoS-awareness, can be used to
investigate the performance of wireless networks under certain statistical
delay constraints. In this paper, we provide a comprehensive survey on existing
works, that use the EC model in various wireless networks. We summarize the
work related to EC for different networks such as cognitive radio networks
(CRNs), cellular networks, relay networks, adhoc networks, and mesh networks.
We explore five case studies encompassing EC operation with different design
and architectural requirements. We survey various delay-sensitive applications
such as voice and video with their EC analysis under certain delay constraints.
We finally present the future research directions with open issues covering EC
maximization
Methods of QoS improvement for P2P IPTV based on traffic modelling
Over the last years many technological advances were introduced in Internet
television to meet user needs and expectations. However due to an overwhelming
bandwidth requirements traditional IP-based television service based on simple
client-server approach remains restricted to small group of clients. In such
situation the use of the peer-to-peer overlay paradigm to deliver live
television on the Internet is gaining increasing attention. Unfortunately the
current Internet infrastructure provides only best effort services for this
kind of applications and do not offer quality of service.
This paper is a research proposition which presents potential solutions for
efficient IPTV streaming over P2P networks. We assume that the solutions will
not directly modify existing P2P IPTV protocols but rather will be dedicated
for a network engineer or an Internet service provider which will be able to
introduce and configure the proposed mechanisms in network routers
A Simple Reinforcement Learning Mechanism for Resource Allocation in LTE-A Networks with Markov Decision Process and Q-Learning
Resource allocation is still a difficult issue to deal with in wireless
networks. The unstable channel condition and traffic demand for Quality of
Service (QoS) raise some barriers that interfere with the process. It is
significant that an optimal policy takes into account some resources available
to each traffic class while considering the spectral efficiency and other
related channel issues. Reinforcement learning is a dynamic and effective
method to support the accomplishment of resource allocation properly
maintaining QoS levels for applications. The technique can track the system
state as feedback to enhance the performance of a given task. Herein, it is
proposed a simple reinforcement learning mechanism introduced in LTE-A networks
and aimed to choose and limit the number of resources allocated for each
traffic class, regarding the QoS Class Identifier (QCI), at each Transmission
Time Interval (TTI) along the scheduling procedure. The proposed mechanism
implements a Markov Decision Process (MDP) solved by the Q-Learning algorithm
to find an optimal action-state decision policy. The results obtained from
simulation exhibit good performance, especially for the real-time Video
application.Comment: 6 pages, 11 figures and 1 tabl
A Survey on QoE-oriented Wireless Resources Scheduling
Future wireless systems are expected to provide a wide range of services to
more and more users. Advanced scheduling strategies thus arise not only to
perform efficient radio resource management, but also to provide fairness among
the users. On the other hand, the users' perceived quality, i.e., Quality of
Experience (QoE), is becoming one of the main drivers within the schedulers
design. In this context, this paper starts by providing a comprehension of what
is QoE and an overview of the evolution of wireless scheduling techniques.
Afterwards, a survey on the most recent QoE-based scheduling strategies for
wireless systems is presented, highlighting the application/service of the
different approaches reported in the literature, as well as the parameters that
were taken into account for QoE optimization. Therefore, this paper aims at
helping readers interested in learning the basic concepts of QoE-oriented
wireless resources scheduling, as well as getting in touch with its current
research frontier.Comment: Revised version: updated according to the most recent related
literature; added references; corrected typo
Greedy-Knapsack Algorithm for Optimal Downlink Resource Allocation in LTE Networks
The Long Term Evolution (LTE) as a mobile broadband technology supports a
wide domain of communication services with different requirements. Therefore,
scheduling of all flows from various applications in overload states in which
the requested amount of bandwidth exceeds the limited available spectrum
resources is a challenging issue. Accordingly, in this paper, a greedy
algorithm is presented to evaluate user candidates which are waiting for
scheduling and select an optimal set of the users to maximize system
performance, without exceeding available bandwidth capacity. The
greedy-knapsack algorithm is defined as an optimal solution to the resource
allocation problem, formulated based on the fractional knapsack problem. A
compromise between throughput and QoS provisioning is obtained by proposing a
class-based ranking function, which is a combination of throughput and QoS
related parameters defined for each application. The simulation results show
that the proposed method provides high performance in terms of throughput, loss
and delay for different classes of QoS over the existing ones, especially under
overload traffic.Comment: Wireless Networks, 201
Review on QoS provisioning approaches for supporting video traffic in IEEE802.11e: challenges and issues
Recently, the demand for multimedia applications is dramatically increased,
which in turn increases the portion of video traffic on the Internet. The video
streams, which require stringent Quality of Service (QoS), are expected to
occupy more than two-thirds of web traffic by 2019. IEEE802.11e has introduced
HCF Controlled Channel Access (HCCA) to provide QoS for delay-sensitive
applications including highly compressed video streams. However, IEEE802.11e
performance is hindered by the dynamic nature of Variable Bit Rate (VBR) video
streams in which packet size and interval time are rapidly fluctuating during
the traffic lifetime. In order to make IEEE802.11e able to accommodate with the
irregularity of VBR video traffic, many approaches have been used in the
literature. In this article, we highlight and discuss the QoS challenges in
IEEE802.11e. Then, we classify the existing QoS approaches in IEEE802.11e and
we also discuss the selection of recent promising and interesting enhancements
of HCCA. Eventually, a set of open research issues and potential future
directions is presented.Comment: 19 page
QoS in IEEE 802.11-based Wireless Networks: A Contemporary Survey
Apart from mobile cellular networks, IEEE 802.11-based wireless local area
networks (WLANs) represent the most widely deployed wireless networking
technology. With the migration of critical applications onto data networks, and
the emergence of multimedia applications such as digital audio/video and
multimedia games, the success of IEEE 802.11 depends critically on its ability
to provide quality of service (QoS). A lot of research has focused on equipping
IEEE 802.11 WLANs with features to support QoS. In this survey, we provide an
overview of these techniques. We discuss the QoS features incorporated by the
IEEE 802.11 standard at both physical (PHY) and media access control (MAC)
layers, as well as other higher-layer proposals. We also focus on how the new
architectural developments of software-defined networking (SDN) and cloud
networking can be used to facilitate QoS provisioning in IEEE 802.11-based
networks. We conclude this paper by identifying some open research issues for
future consideration
Performance Comparison of Packet Scheduling Algorithms for Video Traffic in LTE Cellular Network
In this paper we have studied downlink packet scheduling algorithms proposed
for LTE cellular networks. The study emphasize on three most promising
scheduling algorithms such as: FLS, EXP rule and LOG rule. The performance of
these three algorithms is conducted over video traffic in a vehicular
environment using LTE-Sim simulator. The simulation was setup with varying
number of users from 10 - 60 in fixed bounded regions of 1 km radius. The main
goal this study is to provide results that will help in the design process of
packet scheduler for LTE cellular networks, aiming to get better overall
performance users. Simulation results show that, the FLS scheme outperforms in
terms of average system throughput, average packet delay, PLR; and with a
satisfactory level of fairness index
Analysis, Modification, and Implementation (AMI) of Scheduling Algorithm for the IEEE 802.116e (Mobile WiMAX)
Mobile WiMAX (Worldwide Interoperability for Microwave Access) is being
touted as the most promising and potential broadband wireless technology. And
the popularity rate has been surging to newer heights as the knowledge-backed
service era unfolds steadily. Especially Mobile WiMAX is being projected as a
real and strategic boon for developing counties such as India due to its
wireless coverage acreage is phenomenally high. Mobile WiMAX has spurred
tremendous interest from operators seeking to deploy high-performance yet
cost-effective broadband wireless networks. The IEEE 802.16e standard based
Mobile WiMAX system will be investigated for the purpose of Quality of Service
provisioning. As a technical challenge, radio resource management will be
primarily considered and main is the costly spectrum and the increasingly more
demanding applications with ever growing number of subscribers. It is necessary
to provide Quality of Service (QoS) guaranteed with different characteristics.
As a possible solution the scheduling algorithms will be taken into main
consideration and the present well known algorithms will be described. In this
paper, we have highlighted the following critical issues for Mobile WiMAX
technologies. This paper specifically discussed about the below mentioned in
detail. - QoS Requirements For IEEE 802.16 Service Classes, Achieving efficient
radio resource management. - Deficit Round Robin (DRR) Scheduling algorithm. -
Modified Deficit Round Robin (MDRR) scheduling algorithm's attributes,
properties and architecture. System Model And Scenarios Using OPNET Modeler
Software. - Simulation Limitations And Constraints.Comment: Pages IEEE format, International Journal of Computer Science and
Information Security, IJCSIS, Vol. 7 No. 2, February 2010, USA. ISSN 1947
5500, http://sites.google.com/site/ijcsis
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