Exploiting Multimedia Frame Semantics and MAC-layer Enhancements for QoS Provisioning in IEEE 802.11 e Congested Networks (original) (raw)

Evaluation of QoS Support for Multimedia Traffics in IEEE 802.11e

2006 International Conference on Software in Telecommunications and Computer Networks, 2006

The efficient delivery of multimedia over wireless LANs is strongly dependent on the requirements imposed by different traffics contending the channel resources. Mechanisms for supporting QoS are needed, especially when voice and video applications come into play with stringent constraints in terms of delay and throughput. In this paper we evaluate, through simulations, the benefits derived from the adoption of the IEEE 802.11e standard in delivering multimedia over WLANs. The adoption of fine-tuned parameters regulating the EDCA MAC scheme permits to achieve high performance in terms of goodput and delay, allowing multimedia traffics to fully satisfy their QoS requirements. Realistic assumptions have been made in our simulations, by taking into account the shadowing effects, typical of closed environments, and by adopting suitable parameters to simulate 802.11e channels as exactly as possible.

Improving Ieee 802.11 G Mac to Support Quality of Service for Multimedia Applications in Wireless Networks

This paper paper investigates, describes and propose better techniques to provide QoS by assigning new metrics to the DCF access method, involving the DCF Interframe Space (DIFS), Contention Window values and the maximum data packet size to high priority nodes, which will bias towards high priority multimedia traffic to support QoS. A simulation is done using Network Simulator 2 (NS-2) and comparisons were made between different sets of network simulation scenarios. Improvements on throughput, delay and jitter can clearly be seen and further analysis is then presented.

Dynamic adaptation policies to improve quality of service of real-time multimedia applications in IEEE 802.11e WLAN Networks

Wireless Networks, 2007

With the increased popularity of wireless broadband networks and the growing demand for multimedia applications, such as streaming video and teleconferencing, there is a need to support diverse multimedia services over the wireless medium. In order to efficiently address these diverse needs, efforts have been pursued to provide Quality of Service (QoS) mechanisms for medium access, resulting in a standard called IEEE 802.11e. One of the enhancements proposed in IEEE 802.11e is a polling-based access mechanism, which is targeted for real-time multimedia flows. In this polling-based scheme, scheduling and time allocation are based on flow reservations. Hence, the effectiveness of the mechanism is heavily dependent on the accuracy of the flow requirements in the reservation. Flow requirements, however, can vary over time and an allocation based on fixed reservations cannot address this variability. This limitation, which is present in the reference scheduler of IEEE 802.11e, leads to degraded multimedia quality for flows with variable requirements, even when channel resources are available. In order to address the above limitation, we present an adaptation framework that dynamically adjusts the pollingbased access mechanism and associates flows to different modes of access (polling-based/contention-based), according to the current needs of the application, as opposed to solely relying on the reservation parameters. We demon

High performing multimedia transmission approach based on QoS support and admission control over IEEE 802.11e networks

International Journal of Communication Systems, 2020

Hybrid coordination function controlled channel access (HCCA) is a medium to enhance quality of service (QoS) via the IEEE 802.11e standard. The main limitation of HCAA is that it is only efficient for constant bit rate (CBR) applications. This is due to the nature of its scheduler that allocates transmission opportunities (TXOPs) based on traffic stream (TS) specifications (TSPECs) that are determined during the traffic setup time. Variable bit rate (VBR) traffics used in HCCA have nondeterministic profile, making it not optimally and efficiently supported by HCCA. The result of this inefficiency is a deterioration of the transmission performance of multimedia data as well as a drop in the number of served QoS video traffics. We propose a novel approach to deal with this issue, which is the feedback-based admission control unit (FACU). FACU works by optimizing the usage of extra bandwidth to ensure optimal transmission performance of multimedia data. FACU achieves this by exploiting piggybacked information concerning sequential video frames in order to accurately assign the TXOP. The proposed approach is evaluated by utilizing various video sequences. It is demonstrated that FACU maximizes the overall number of video streams and optimizes the overall usage of the network without having any adverse effects on the QoS constraints determined.

Traffic scheduling for multimedia QoS over wireless LANs

IEEE International Conference on Communications, 2005. ICC 2005. 2005, 2005

In this paper we present a novel traffic scheduling algorithm for IEEE 802.11e, referred to as ARROW (Adaptive Resource Reservation Over WLANs), able to handle multimedia traffic. The novel characteristic of ARROW is that it performs channel allocations based on the actual traffic (not estimated traffic) buffered in the various mobile stations. Additionally, a variation of ARROW is studied for improving the performance for constant bit rate traffic. The ARROW algorithm and its enhancement are evaluated against two other schedulers found in the literature, namely the Simple Scheduler and SETT-EDD. Results from a detailed simulation model show that much better channel utilization and considerably improved performance can be provided. A.

Performance evaluation of the QOS provisioning ability of IEEE 802.11e WLAN standard for multimedia traffic

ArXiv, 2021

This paper presents an analytical model for the average frame transmission delay and the jitter for the different Access Categories (ACs) of the IEEE 802.11e Enhanced Distributed Channel Access (EDCA) mechanism. Following are the salient features of our model. As defined by the standard we consider (1) the virtual collisions among different ACs inside each EDCA station in addition to external collisions. (2) the effect of priority parameters, such as minimum and maximum values of Contention Window (CW) sizes, Arbitration Inter Frame Space (AIFS). (3) the role of Transmission Opportunity (TXOP) of different ACs. (4) the finite number of retrials a packet experiences before being dropped. Our model and analytical results provide an in depth understanding of the EDCA mechanism and the effect of Quality of Service (QoS) parameters in performance of IEEE 802.11e protocol.

Dynamic prioritization of multimedia flows for improving QoS and throughput in IEEE 802.11 e WLANs

… , 2005. ICC 2005. 2005 …, 2005

In wireless LANs, QoS provisioning and multimedia traffic support are critical elements for the successful deployment of such networks. In this paper, we propose a dynamic mechanism to adapt data rate and priority of multimedia wireless stations equipped with IEEE 802.11e network cards. We will show how the introduced dynamicity is able to improve performance of the Enhanced Distributed Channel Access (EDCA) of IEEE 802.11e networks.

Adaptive Multimedia Packet Transmission for Broadband IEEE 802.11 Wireless Lans

2006 IEEE 17th International Symposium on Personal, Indoor and Mobile Radio Communications, 2006

The IEEE 802.11 suite of WLAN standards are evolving to support an increase in emerging broadband multimedia applications, with their popularity attributed to simple, scalable and cost effective wireless broadband communication infrastructure. However, the most widely deployed generation of 802.11x based MAC protocols provide limited support for multimedia traffic, as no guarantee is provided on the quality of service (QoS) that a particular type of traffic will receive. Furthermore, the legacy 802.11 MAC exhibits high protocol overhead due to control frames, channel access, and the probability of contention. This article presents an overview of MAC layer enhancements designed to provide QoS support and higher throughputs in next generation WLANs, including IEEE 802.11e and 802.11n standards. Comprehensive simulation results are provided using an OPNET simulation model.

Modified MAC for Priority Traffic with Slow Decrease of Contention Window and Reservation Based Packet Forwarding in IEEE 802.11 for QoS Provisioning

2008

IEEE 802.11 lacks of the capability to support Quality of Services such as multimedia and real-time traffic properly. This paper presents a simple approach to enhance the multimedia real-time performance over the 802.11 WLAN by implementing a Quality of Service Manager (QoSM) for differentiating services with two queues on top of the 802.11 Medium Access controller. With slow decrease of contention window (SD) and reservation based packet forwarding. The proposed scheme is verified with the help of ns-2 and an improved performance for multimedia real-time service in the infrastructure-based WLAN with the coexistence of the non-real time traffic.

A Dynamic Multimedia User-Weight Classification Scheme for IEEE_802. 11 WLANS

In this paper we expose a dynamic traffic-classification scheme to support multimedia applications such as voice and broadband video transmissions over IEEE 802.11 Wireless Local Area Networks (WLANs). Obviously, over a Wi-Fi link and to better serve these applications-which normally have strict bounded transmission delay or minimum link rate requirementa service differentiation technique can be applied to the media traffic transmitted by the same mobile node using the well-known 802.11e Enhanced Distributed Channel Access (EDCA) protocol. However, the given EDCA mode does not offer user differentiation, which can be viewed as a deficiency in multi-access wireless networks. Accordingly, we propose a new inter-node priority access scheme for IEEE 802.11e networks which is compatible with the EDCA scheme. The proposed scheme joins a dynamic user-weight to each mobile station depending on its outgoing data, and therefore deploys inter-node priority for the channel access to complement the existing EDCA inter-frame priority. This provides efficient quality of service control across multiple users within the same coverage area of an access point. We provide performance evaluations to compare the proposed access model with the basic EDCA 802.11 MAC protocol mode to elucidate the quality improvement achieved for multimedia communication over 802.11 WLANs.