Enhancement of Adaptive Forward Error Correction Mechanism for Video Transmission Over Wireless Local Area Network

Video transmission over the wireless network faces many challenges. The most critical challenge is related to packet loss. To overcome the problem of packet loss, Forward Error Correction is used by adding extra packets known as redundant packet or parity packet. Currently, FEC mechanisms have been adopted together with Automatic Repeat reQuest (ARQ) mechanism to overcome packet losses and avoid network congestion in various wireless network conditions. The number of FEC packets need to be generated effectively because wireless network usually has varying network conditions. In the current Adaptive FEC mechanism, the FEC packets are decided by the average queue length and average packet retransmission times. The Adaptive FEC mechanisms have been proposed to suit the network condition by generating FEC packets adaptively in the wireless network. However, the current Adaptive FEC mechanism has some major drawbacks such as the reduction of recovery performance which injects too many excessive FEC packets into the network. This is not flexible enough to adapt with varying wireless network condition. Therefore, the enhancement of Adaptive FEC mechanism (AFEC) known as Enhanced Adaptive FEC (EnAFEC) has been proposed. The aim is to improve recovery performance on the current Adaptive FEC mechanism by injecting FEC packets dynamically based on varying wireless network conditions. The EnAFEC mechanism is implemented in the simulation environment using Network Simulator 2 (NS-2). Performance evaluations are also carried out. The EnAFEC was tested with the random uniform error model. The results from experiments and performance analyses showed that EnAFEC mechanism outperformed the other Adaptive FEC mechanism in terms of recovery efficiency. Based on the findings, the optimal amount of FEC generated by EnAFEC mechanism can recover high packet loss and produce good video quality

Measuring And Improving Internet Video Quality Of Experience

Streaming multimedia content over the IP-network is poised to be the dominant Internet traffic for the coming decade, predicted to account for more than 91% of all consumer traffic in the coming years. Streaming multimedia content ranges from Internet television (IPTV), video on demand (VoD), peer-to-peer streaming, and 3D television over IP to name a few. Widespread acceptance, growth, and subscriber retention are contingent upon network providers assuring superior Quality of Experience (QoE) on top of todays Internet. This work presents the first empirical understanding of Internet’s video-QoE capabilities, and tools and protocols to efficiently infer and improve them. To infer video-QoE at arbitrary nodes in the Internet, we design and implement MintMOS: a lightweight, real-time, noreference framework for capturing perceptual quality. We demonstrate that MintMOS’s projections closely match with subjective surveys in accessing perceptual quality. We use MintMOS to characterize Internet video-QoE both at the link level and end-to-end path level. As an input to our study, we use extensive measurements from a large number of Internet paths obtained from various measurement overlays deployed using PlanetLab. Link level degradations of intra– and inter–ISP Internet links are studied to create an empirical understanding of their shortcomings and ways to overcome them. Our studies show that intra–ISP links are often poorly engineered compared to peering links, and that iii degradations are induced due to transient network load imbalance within an ISP. Initial results also indicate that overlay networks could be a promising way to avoid such ISPs in times of degradations. A large number of end-to-end Internet paths are probed and we measure delay, jitter, and loss rates. The measurement data is analyzed offline to identify ways to enable a source to select alternate paths in an overlay network to improve video-QoE, without the need for background monitoring or apriori knowledge of path characteristics. We establish that for any unstructured overlay of N nodes, it is sufficient to reroute key frames using a random subset of k nodes in the overlay, where k is bounded by O(lnN). We analyze various properties of such random subsets to derive simple, scalable, and an efficient path selection strategy that results in a k-fold increase in path options for any source-destination pair; options that consistently outperform Internet path selection. Finally, we design a prototype called source initiated frame restoration (SIFR) that employs random subsets to derive alternate paths and demonstrate its effectiveness in improving Internet video-QoE

Hybrid FLUTE/DASH video delivery over mobile wireless networks

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-

Video over DSL with LDGM Codes for Interactive Applications

Digital Subscriber Line (DSL) network access is subject to error bursts, which, for interactive video, can introduce unacceptable latencies if video packets need to be re-sent. If the video packets are protected against errors with Forward Error Correction (FEC), calculation of the application-layer channel codes themselves may also introduce additional latency. This paper proposes Low-Density Generator Matrix (LDGM) codes rather than other popular codes because they are more suitable for interactive video streaming, not only for their computational simplicity but also for their licensing advantage. The paper demonstrates that a reduction of up to 4 dB in video distortion is achievable with LDGM Application Layer (AL) FEC. In addition, an extension to the LDGM scheme is demonstrated, which works by rearranging the columns of the parity check matrix so as to make it even more resilient to burst errors. Telemedicine and video conferencing are typical target applications