scholarly journals Effect of service differentiation on QoS in IEEE 802.11e enhanced distributed channel access: a simulation approach

2022 ◽  
Vol 69 (1) ◽  
Author(s):  
Godwin Onyekachi Ugwu ◽  
Udora Nwabuoku Nwawelu ◽  
Mamilus Aginwa Ahaneku ◽  
Cosmas Ikechukwu Ani
Keyword(s):  
Service Differentiation ◽  
Ieee 802.11E ◽  
Multimedia Traffic ◽  
Channel Access ◽  
Medium Access ◽  
Lower Priority ◽  
Depth Analysis ◽  
Inter Frame ◽  
Research Show

AbstractThe enhanced distributed channel access (EDCA) protocol is a supplement to IEEE 802.11 medium access control (MAC), ratified by IEEE 802.11e task group to support quality of service (QoS) requirements of both data and real-time applications. Previous research show that it supports priority scheme for multimedia traffic but strict QoS is not guaranteed. This can be attributed to inappropriate tuning of the medium access parameters. Thus, an in-depth analysis of the EDCA protocol and ways of tuning medium access parameters to improve QoS requirements for multimedia traffic is presented in this work. An EDCA model was developed and simulated using MATLAB to assess the effect of differentiating contention window (CW) and arbitration inter-frame space (AIFS) of different traffic on QoS parameters. The optimal performance, delay, and maximum sustainable throughput for each traffic type were computed under saturation load. Insight shows that traffic with higher priority values acquired most of the available channels and starved traffic with lower priority values. The AIFS has more influence on the QoS of EDCA protocol. It was also observed that small CW values generate higher packet drops and collision rate probability. Thus, EDCA protocol provides mechanism for service differentiation which strongly depends on channel access parameters: CW sizes and AIFS.

Distributed TXOP Allocation Scheme in IEEE 802.11e Wireless LANs

2013 ◽  
Vol 284-287 ◽  
pp. 2904-2907
Author(s):  
Sunmyeng Kim
Keyword(s):  
Quality Of Service ◽  
Wireless Lans ◽  
Service Differentiation ◽  
Ieee 802.11E ◽  
Multimedia Traffic ◽  
Allocation Scheme ◽  
Delay Bound ◽  
Transmission Opportunity ◽  
Simulation Results

Multimedia traffic is expected to be one of the most important traffic types in wireless LANs. However, multimedia traffic is very sensitive to delay so that the traffic has to be transmitted to receivers within its delay bound. The IEEE 802.11e EDCA (Enhanced Distributed Channel Access) defines a TXOP (Transmission Opportunity) parameter to provide service differentiation and QoS (Quality of Service) of the traffic. A station can continuously transmit multiple packets for the duration of a TXOP. When stations support multimedia applications with different QoS requirements, fairness problem occurs. In order to alleviate the fairness problem, we propose a distributed TXOP allocation scheme based on the delay bound. In the proposed scheme, a station checks the delay bound of each data packet in the queue, and allocates its TXOP value to guarantee the delay bounds of all the packets in the queue. Simulation results show that the proposed scheme outperforms other TXOP allocation schemes.

scholarly journals Elastic QoS Scheduling with Step-by-Step Propagation in IEEE 802.11e Networks with Multimedia Traffic

2019 ◽  
Vol 2019 ◽  
pp. 1-23 ◽  
Author(s):  
Anna Lina Ruscelli ◽  
Gabriele Cecchetti ◽  
Piero Castoldi
Keyword(s):  
Physical Layer ◽  
Service Differentiation ◽  
Transmission Time ◽  
Ieee 802.11E ◽  
Service Needs ◽  
Virtual Training ◽  
Time Service ◽  
Depth Analysis ◽  
Feasibility Test ◽  
Service Data

The spreading diffusion of wireless devices and the crowded coexistence of multimedia applications greedy of bandwidth and with strict requirements stress the service provisioning offered by wireless technologies. WiFi is a reference for wireless connectivity and it requires a continuous evolution of its mechanism in order to follow increasingly demanding service needs. In particular, despite the evolution of physical layer, some critical contexts, such as industrial networks, telemedicine, telerehabilitation, and virtual training, require further refined improvements in order to ensure the respect of strict real-time service requirements. In this paper an in-depth analysis of Dynamic TXOP HCCA (DTH) MAC enhanced centralized scheduler is illustrated and it is further refined introducing a new improvement, DTH with threshold. DTH and DTH with threshold can be integrated with preexisting centralized schedulers in order to improve their performances, without any overprovisioning that can negatively impact on the admission control feasibility test. Indeed, without modifying the centralized scheduler policy, they combine together the concepts of reclaiming transmission time and statistical estimation of the traffic profile in order to provide, at each polling, an instantaneous transmission time tailored to the variable traffic requirements, increasing, when necessary, the service data rate. These mechanisms can coexist with advanced physical layer-based solutions, providing the required service differentiation. Experimental results and theoretical analysis, based on elastic scheduler theory, show that they are effective especially in the case of Variable Bit Rate traffic streams in terms of transmission queues length, packets loss, delay, and throughput.

scholarly journals Παροχή ποιότητας υπηρεσιών σε ασύρματα τοπικά δίκτυα πολυμέσων τεχνολογίας ΙΕΕΕ 802.11e

2011 ◽  
Author(s):  
Αναστάσιος Πολίτης
Keyword(s):  
Ieee 802.11 ◽  
Local Area ◽  
Multimedia Applications ◽  
Ieee 802.11E ◽  
Medium Access ◽  
Large Numbers ◽  
Integrated Architecture ◽  
Wireless Infrastructure ◽  
Networking Technology

The fast growth of Wireless Local Area Networks (WLANs) during the last decade, has led to their wide acceptance by the vast majority of electronic equipment users as the dominant wireless networking technology. The indisputable functionality standard of WLANs is the IEEE 802.11. At the same time, multimedia applications technology has received a similar success. It was, therefore, an expected result that the users of both technologies required that multimedia applications were adequately supported by the wireless infrastructure. Towards this direction, the IEEE has published a series of amendments to the initial WLAN standard. The widely accepted amendment for supporting multimedia in WLANs is the IEEE 802.11e. This specification defined the functionality of a new Medium Access Control (MAC), capable of providing Quality of Service (QoS) to applications with high demands from the network.However, the IEEE 802.11 has received negative reviews regarding its capability of multimedia support in highly congested wireless networks. These conditions are quite common, especially in infrastructure networks with large numbers of users (e.g., public hotspots, university networks etc.). As a response to this challenge, the international scientific community, has designed and proposed various enhancements mechanisms to improve the IEEE 802.11e functionality in high load situations.This thesis contributes to this international effort of QoS provisioning in multimedia WLANs, by developing and assessing a novel mechanism which combines, adapts and enforces the characteristics and the design techniques that have been proposed in the international bibliography, into an integrated architecture. The efficiency of the mechanism is evaluated and compared to other implementations, and the related experimental results are proven to be very promising.

scholarly journals Latency and Jitter Analysis for IEEE 802.11e Wireless LANs

2013 ◽  
Vol 2013 ◽  
pp. 1-9
Author(s):  
Sungkwan Youm ◽  
Eui-Jik Kim
Keyword(s):  
Local Area ◽  
Ieee 802.11E ◽  
Distributed Coordination ◽  
Mac Layer ◽  
Medium Access ◽  
Distributed Coordination Function ◽  
Packet Latency ◽  
Coordination Function ◽  
The Voice

This paper presents a numerical analysis of latency and jitter for IEEE 802.11e wireless local area networks (WLANs) in a saturation condition, by using a Markov model. We use this model to explicate how the enhanced distributed coordination function (EDCF) differentiates classes of service and to characterize the probability distribution of the medium access control (MAC) layer packet latency and jitter, on which the quality of the voice over Internet protocol (VoIP) calls is dependent. From the proposed analytic model, we can estimate the available number of nodes determining the system performance, in order to satisfy user demands on the latency and jitter.

scholarly journals DQOBSR Protocol with QoS Provisioning for OBS Metro Rings

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
M. Thachayani ◽  
R. Nakkeeran
Keyword(s):  
Mac Protocol ◽  
Service Differentiation ◽  
Wavelength Converters ◽  
Ring Networks ◽  
Qos Provisioning ◽  
Medium Access ◽  
Optical Internet ◽  
Access Delay ◽  
Distributed Queue

Optical burst switching (OBS) is the switching technology that enables optical internet with current technology. OBS networks are capable of operating with or without optical buffers and wavelength converters. Hence, medium access control (MAC) protocol plays an important role in resolving contention in such networks. Distributed Queue OBS Ring (DQOBSR) is one MAC protocol proposed for OBS ring networks. In this paper, the quality of service (QoS) provisioning scheme for DQOBSR protocol is presented. For the proposed protocol, service differentiation for different classes of traffic in terms of throughput and access delay is verified through simulation. A mathematical model is also presented for the computation of classwise mean access delay. The results obtained using the model are found to be in good agreement with the simulation results.

scholarly journals Improving WLAN Quality of Services (Qos) Using Opnet

2016 ◽  
Vol 9 (3) ◽  
pp. 204-211
Author(s):  
Ishwar Baidari ◽  
S. P. Sajjan ◽  
Ajeet Singh
Keyword(s):  
Ieee 802.11 ◽  
Local Area Networks ◽  
Local Area ◽  
Wireless Local Area Networks ◽  
Ieee 802.11E ◽  
Distributed Coordination ◽  
Medium Access ◽  
Access Delay ◽  
Coordination Function

Wireless local area networks (WLANs) are in a period of great expansion and there is a strong need for them to support multimedia applications. With the increasing demand and penetration of wireless services, users of wireless networks now expect Quality of Service (QoS) and performance comparable to what is available from fixed networks. Providing QoS requirements like good throughput and minimum access delay are challenging tasks with regard to 802.11 WLAN protocols and Medium Access Control (MAC) functions. This research is done to study, the presently implemented schemes (the Point Coordination Function (PCF) of IEEE 802.11, the Enhanced Distributed Coordination Function (EDCF) of the proposed IEEE 802.11e extension to IEEE 802.11), solves these issues and what can be done to improve them further. The metrics used were Throughput, Data Drop, Retransmission and Medium Access Delay, to analyze the performance of various MAC protocols in providing QoS to users of WLAN. Two scenarios, with same Physical and MAC parameters, one implementing the DCF and other EDCF, were created in the network simulation tool (OPNET MODELER) to obtain the results. The results showed that the performance of EDCF was better in providing QoS for real-time interactive services (like video conferencing) as compared to DCF, because of its ability to differentiate and prioritize various services. Index Terms - Wireless local area networks (WLANs),

scholarly journals Performance Analysis of the Differences Restricted Access Window (RAW) on IEEE 802.11ah Standard with Enhanced Distributed Channel Access (EDCA)

2018 ◽  
Vol 10 (4) ◽  
pp. 163
Author(s):  
Mulki Nurullah Perbawa ◽  
Doan Perdana ◽  
Yoseph Gustommy Bisono
Keyword(s):  
Energy Consumption ◽  
Wireless Lan ◽  
Delivery Ratio ◽  
Channel Access ◽  
Average Delay ◽  
Restricted Access ◽  
Ieee 802.11Ah ◽  
Machine Communication ◽  
Inter Frame

IEEE 802.11 standard is a WLAN (Wireless LAN) standard that has been used in all over the world. IEEE 802.11ah is the newer technology that designed to supports Internet of Things (IoT) and Machine-to-machine Communication (M2M).  IEEE 802.11ah has a feature called Restricted Access Window (RAW) that capable to reduce power usage and have satisfying Quality of Service (QoS). In this research, Enhanced Distributed Channel Access (EDCA) is also applied. Same as RAW, EDCA also be able to affect QoS by modified the MAC Layer in 802.11 standard. This research used 3 different scenarios for RAW parameters: Modifying the number of RAW Group, Modifying the number of RAW Slot, and Comparing 2 Datamode. The EDCA Parameters that used in this research were: Contention Window and Arbitrary inter-frame Spacing Number.  The values that expected to be the output in this research are: Delay, Throughput, Packet Delivery Ratio, Availability, and Reliability. After the research has been simulated, the results are: First, the lowest of average delay was Ngroup = 1, the highest of PDR was Ngroup = Nsta/2, and the highest of Throughput was Ngroup = Nsta/2. Second, the lowest of average delay was RAW Slot = 6, the highest of PDR were RAW Slot = 3 and 4, and the highest of Throughput was RAW Slot = 4. Third, the lowest of average delay was Datamode 3,9 Mbps BW 2 MHz, the highest of PDR was Dat mode 3,9 Mbps BW 2 MHz, and the highest of Throughput was Datamode 3,9 Mbps BW 2 MHz. Reliability, Availability, and Energy Consumption also can be affected by modifying RAW parameters, in 802.11ah Energy Consumption can be reduced by increasing the number of RAW Stations and RAW Groups.

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