48 research outputs found

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

    Full text link
    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 requirement - a 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.Comment: 15 pages, 8 figures, 3 tables, International Journal of Computer Networks & Communications (IJCNC

    Efficient Transmission of H.264 Video over Multirate IEEE 802.11e WLANs

    Get PDF
    The H.264 video encoding technology, which has emerged as one of the most promising compression standards, offers many new delivery-aware features such as data partitioning. Efficient transmission of H.264 video over any communication medium requires a great deal of coordination between different communication network layers. This paper considers the increasingly popular and widespread 802.11 Wireless Local Area Networks (WLANs) and studies different schemes for the delivery of the baseline and extended profiles of H.264 video over such networks. While the baseline profile produces data similar to conventional video technologies, the extended profile offers a partitioning feature that divides video data into three sets with different levels of importance. This allows for the use of service differentiation provided in the WLAN. This paper examines the video transmission performance of the existing contention-based solutions for 802.11e, and compares it to our proposed scheduled access mechanism. It is demonstrated that the scheduled access scheme outperforms contention-based prioritized services of the 802.11e standard. For partitioned video, it is shown that the overhead of partitioning is too high, and better results are achieved if some partitions are aggregated. The effect of link adaptation and multirate operation of the physical layer (PHY) is also investigated in this paper

    Quality of service differentiation for multimedia delivery in wireless LANs

    Get PDF
    Delivering multimedia content to heterogeneous devices over a variable networking environment while maintaining high quality levels involves many technical challenges. The research reported in this thesis presents a solution for Quality of Service (QoS)-based service differentiation when delivering multimedia content over the wireless LANs. This thesis has three major contributions outlined below: 1. A Model-based Bandwidth Estimation algorithm (MBE), which estimates the available bandwidth based on novel TCP and UDP throughput models over IEEE 802.11 WLANs. MBE has been modelled, implemented, and tested through simulations and real life testing. In comparison with other bandwidth estimation techniques, MBE shows better performance in terms of error rate, overhead, and loss. 2. An intelligent Prioritized Adaptive Scheme (iPAS), which provides QoS service differentiation for multimedia delivery in wireless networks. iPAS assigns dynamic priorities to various streams and determines their bandwidth share by employing a probabilistic approach-which makes use of stereotypes. The total bandwidth to be allocated is estimated using MBE. The priority level of individual stream is variable and dependent on stream-related characteristics and delivery QoS parameters. iPAS can be deployed seamlessly over the original IEEE 802.11 protocols and can be included in the IEEE 802.21 framework in order to optimize the control signal communication. iPAS has been modelled, implemented, and evaluated via simulations. The results demonstrate that iPAS achieves better performance than the equal channel access mechanism over IEEE 802.11 DCF and a service differentiation scheme on top of IEEE 802.11e EDCA, in terms of fairness, throughput, delay, loss, and estimated PSNR. Additionally, both objective and subjective video quality assessment have been performed using a prototype system. 3. A QoS-based Downlink/Uplink Fairness Scheme, which uses the stereotypes-based structure to balance the QoS parameters (i.e. throughput, delay, and loss) between downlink and uplink VoIP traffic. The proposed scheme has been modelled and tested through simulations. The results show that, in comparison with other downlink/uplink fairness-oriented solutions, the proposed scheme performs better in terms of VoIP capacity and fairness level between downlink and uplink traffic

    Hybrid FLUTE/DASH video delivery over mobile wireless networks

    Full text link
    This paper describes how FLUTE (File Delivery over Unidirectional Transport) and DASH (Dynamic Adaptive Streaming over HTTP) can be used to provide mobile video streaming services over broadcast wireless networks. FLUTE is a multicast protocol for multimedia file download. In this proposal, the protocol is adapted to provide video streaming services in crowded environments. Thus, video is delivered over a single connection to all viewers, reducing the traffic in the network. FLUTE incorporates an AL-FEC (Application Layered Forward Error Correction) mechanism in order to improve the reliability of the broadcast communication channel. For streaming applications, AL-FEC improves the relationship between the PSNR (Peak Signal-to-Noise Ratio) of the received video and the bandwidth allocated to the broadcast connection. The AL-FEC hereby presented applies simple unequal error protection schemes to favor the download of key frames. Furthermore, the proposal is based on the same video segmentation mechanism as DASH and therefore, clients can connect to a DASH repository to repair errors in the segments. This paper shows that FLUTE and DASH can be seamlessly integrated into a hybrid broadcast/unicast streaming technology, providing flexibility to trade off PSNR and bandwidth depending on the conditions of the mobile network.This work was supported by the 11012 ICARE (Innovative Cloud Architecture for Real Entertainment) project within the ITEA 2 Call 6 Program of the European Union.Belda Ortega, R.; De Fez Lava, I.; Fraile Gil, F.; Arce Vila, P.; Guerri Cebollada, JC. (2014). Hybrid FLUTE/DASH video delivery over mobile wireless networks. Transactions on Emerging Telecommunications Technologies. 25(11):1070-1082. doi:10.1002/ett.2804S107010822511ETSI TS 126 346 v11.3.0. Universal Mobile Telecommunications Systems (UMTS); LTE; Multimedia Broadcast/Multicast Service (MBMS); Protocols and Codecs 2013Lecompte, D., & Gabin, F. (2012). Evolved multimedia broadcast/multicast service (eMBMS) in LTE-advanced: overview and Rel-11 enhancements. IEEE Communications Magazine, 50(11), 68-74. doi:10.1109/mcom.2012.6353684Stockhammer T Luby MG DASH in mobile networks and services. Presented at IEEE Visual Communications and Image Processing (VCIP) , 2012Seeling, P., & Reisslein, M. (2012). Video Transport Evaluation With H.264 Video Traces. IEEE Communications Surveys & Tutorials, 14(4), 1142-1165. doi:10.1109/surv.2011.082911.00067Zhao, S., Tuninetti, D., Ansari, R., & Schonfeld, D. (2012). Multiple description coding over multiple correlated erasure channels. Transactions on Emerging Telecommunications Technologies, 23(6), 522-536. doi:10.1002/ett.2507Lin, C.-H., Wang, Y.-C., Shieh, C.-K., & Hwang, W.-S. (2012). An unequal error protection mechanism for video streaming over IEEE 802.11e WLANs. Computer Networks, 56(11), 2590-2599. doi:10.1016/j.comnet.2012.04.004Paila T Walsh R Luby M Roca V Lehtonen R FLUTE - file delivery over unidirectional transport. 2012Luby M Watson M Vicisano L Asynchronous layered coding (ALC) protocol instantiation. 2010Ameigeiras, P., Ramos-Munoz, J. J., Navarro-Ortiz, J., & Lopez-Soler, J. M. (2012). Analysis and modelling of YouTube traffic. Transactions on Emerging Telecommunications Technologies, 23(4), 360-377. doi:10.1002/ett.2546ISO/IEC 23009-1. Dynamic adaptive streaming over HTTP (DASH) - Part 1: media presentation description and segment formats 2012De Fez, I., Fraile, F., Belda, R., & Guerri, J. C. (2012). Analysis and Evaluation of Adaptive LDPC AL-FEC Codes for Content Download Services. IEEE Transactions on Multimedia, 14(3), 641-650. doi:10.1109/tmm.2012.2190392Jenkac, H., Stockhammer, T., & Wen Xu. (2006). Asynchronous and reliable on-demand media broadcast. IEEE Network, 20(2), 14-20. doi:10.1109/mnet.2006.1607891Neumann C Roca V Scalable video streaming over ALC (SVSoA): a solution for the large scale multicast distribution of videos. Presented at 1st Int. Workshop on SMDI , 2004Lederer S Müller C Timmerer C Dynamic adaptive streaming over HTTP dataset Proc. of the ACM Conference on Multimedia Systems (MMSys) 2012 89 94Blender Foundation webpage http://www.blender.org/blenderorg/Bai, H., & Atiquzzaman, M. (2003). Error modeling schemes for fading channels in wireless communications: A survey. IEEE Communications Surveys & Tutorials, 5(2), 2-9. doi:10.1109/comst.2003.5341334Ohm, J.-R. (2004). Multimedia Communication Technology. Signals and Communication Technology. doi:10.1007/978-3-642-18750-

    Network-aware Adaptation with Real-Time Channel Statistics for Wireless LAN Multimedia Transmissions in the Digital Home

    Full text link
    This paper suggests the use of intelligent network-aware processing agents in wireless local area network drivers to generate metrics for bandwidth estimation based on real-time channel statistics to enable wireless multimedia application adaptation. Various configurations in the wireless digital home are studied and the experimental results with performance variations are presented.Comment: 6 pages, 12 figure

    60 GHz MAC Standardization: Progress and Way Forward

    Full text link
    Communication at mmWave frequencies has been the focus in the recent years. In this paper, we discuss standardization efforts in 60 GHz short range communication and the progress therein. We compare the available standards in terms of network architecture, medium access control mechanisms, physical layer techniques and several other features. Comparative analysis indicates that IEEE 802.11ad is likely to lead the short-range indoor communication at 60 GHz. We bring to the fore resolved and unresolved issues pertaining to robust WLAN connectivity at 60 GHz. Further, we discuss the role of mmWave bands in 5G communication scenarios and highlight the further efforts required in terms of research and standardization

    Quality of service based distributed control of wireless networks

    Get PDF

    Video QoS/QoE over IEEE802.11n/ac: A Contemporary Survey

    Get PDF
    The demand for video applications over wireless networks has tremendously increased, and IEEE 802.11 standards have provided higher support for video transmission. However, providing Quality of Service (QoS) and Quality of Experience (QoE) for video over WLAN is still a challenge due to the error sensitivity of compressed video and dynamic channels. This thesis presents a contemporary survey study on video QoS/QoE over WLAN issues and solutions. The objective of the study is to provide an overview of the issues by conducting a background study on the video codecs and their features and characteristics, followed by studying QoS and QoE support in IEEE 802.11 standards. Since IEEE 802.11n is the current standard that is mostly deployed worldwide and IEEE 802.11ac is the upcoming standard, this survey study aims to investigate the most recent video QoS/QoE solutions based on these two standards. The solutions are divided into two broad categories, academic solutions, and vendor solutions. Academic solutions are mostly based on three main layers, namely Application, Media Access Control (MAC) and Physical (PHY) which are further divided into two major categories, single-layer solutions, and cross-layer solutions. Single-layer solutions are those which focus on a single layer to enhance the video transmission performance over WLAN. Cross-layer solutions involve two or more layers to provide a single QoS solution for video over WLAN. This thesis has also presented and technically analyzed QoS solutions by three popular vendors. This thesis concludes that single-layer solutions are not directly related to video QoS/QoE, and cross-layer solutions are performing better than single-layer solutions, but they are much more complicated and not easy to be implemented. Most vendors rely on their network infrastructure to provide QoS for multimedia applications. They have their techniques and mechanisms, but the concept of providing QoS/QoE for video is almost the same because they are using the same standards and rely on Wi-Fi Multimedia (WMM) to provide QoS
    corecore