Laith Al-Jobouri

Protecting H.264/AVC data-partitioned video streams over broadband WiMAX

Broadband wireless technology, though aimed at video services, also poses a potential threat to video services, as wireless channels are prone to error bursts. In this paper, an adaptive, application-layer Forward Error Correction (FEC) scheme protects H.264/AVC data-partitioned video. Data partitioning is the division of a compressed video stream into partitions of differing decoding importance. The paper determines whether equal error protection (EEP) through FEC of all partition types or unequal error protection (UEP) of the more important partition type is preferable. The paper finds that, though UEP offers a small reduction in bitrate, if EEP is employed, there are significant gains (several dBs) in video quality. Overhead from using EEP rather than UEP was found to be around 1% of the overall bitrate. Given that data partitioning already reduces errors through packet size reduction and differentiation of coding data, EEP with data partitioning is a practical means of protecting user-based video streaming. The gain from employing EEP is shown to be higher quality video to the user, which will result in a greater take-up of video services. The results have implications for other forms of prioritized video streaming.

Error Resilient IPTV for an IEEE 802.16e Channel

Data-partitioning of IPTV video streams is a way of providing graceful quality degradation in a form that will work in good and difficult wireless channel conditions, as experienced by mobile devices. This paper’s proposal is to combine redundant slice protection along with an adaptive channel coding scheme that is also proposed in the paper. Adaptive channel coding is achieved by retransmission when necessary of additional redundant data to reconstruct corrupted packets. In the proposal, outright packet loss is provided for by a form of redundant slice protection. The paper finds that it is preferable: not to simply protect only the highest priority packets; that a moderate quantization level should be employed; and that video quality is differentiated by content type. It is important also to configure the partitioning correctly to remove inter-partition dependencies when possible.

Multicast and unicast video streaming with rateless channel-coding over wireless broadband

Prior research on wireless multicast video streaming has addressed the risk of feedback implosion when providing adaptive forward error correction (FEC). This approach has not been adopted by providers, who may either stick to unicast streaming or use a sufficient level of application layer FEC to avoid the need for adaptation. Instead in this paper, an adaptive unicast rateless channel coding scheme is also run in multicast mode. This is accomplished simply by turning off requests for FEC repair data. The paper demonstrates the concept and provides an indication of the operating conditions for such a joint multicast/unicast service in terms of data rates and suitable video content type.

Adaptive rateless coding for data-partitioned video streaming over a broadband wireless channel

Fixed-rate, rateless channel coding is attractive for its linear decoder computational complexity. Though fixed rate coding is appropriate for broadcast systems, this paper proposes adaptive coding for unicast, data-partitioned compressed video streams. The paper finds that the main gain from such a scheme is an increase in goodput and wireless channel utilization, which is important for a real-time service. In fact, in an ideal scheme no retransmissions are needed to repair packets corrupted by channel errors. Video quality is also potentially enhanced by the differential packet drop rates at buffers that result in less important data-partition bearing packets dropped more frequently.

Engineering wireless broadband access to IPTV

We demonstrate effective codec configuration for wireless IPTV video streaming.We demonstrate multiple protection measures for a wireless IPTV service.We report performance over WiMAX access links with bursty error conditions.We report broadband wireless IPTV prospects. IPTV is now extending to wireless broadband access. If broadband video streaming is to achieve competitive quality the video stream itself must be carefully engineered to cope with challenging wireless channel conditions. This paper presents a scheme for doing this for H.264/AVC codec streaming across a WiMAX link. Packetization is an effective tool to govern error rates and, in the paper, source-coded data-partitioning serves to allocate smaller packets to more important data. A packetization strategy is insufficient in itself, as temporal error propagation should also be addressed by insertion of intra-coded data. It may be necessary to include redundant packets when channel conditions worsen. The whole should be protected by application-layer rateless coding. Therefore, the contribution of the paper is a complete scheme comprised of various protection measures aimed at robust IPTV streaming. Due to computational overheads, the scheme is aimed at the new generation of smartphones with GHz CPUs.

Increasing the rate of intrusion detection based on a hybrid technique

This paper presents techniques to increase intrusion detection rates. Theses techniques are based on specific features that are detected and its shown that a small number of features (9) can yield improved detection rates compared to higher numbers. These techniques utilize soft computing techniques such a Backpropagation based artificial neural networks and fuzzy sets. These techniques achieve a significant improvement over the state of the art for standard DARPA benchmark data.

Raptor coding of H.264 data-partitioned video over a WiMAX channel

This paper demonstrates robust video streaming for IPTV over WiMAX. In the proposed method, an H.264/AVC video bit-stream is data partitioned according to data priority. Raptor channel coding is adaptively applied to the partitioned data. In the event of outright packet drops, redundant partition bearing packets serve to protect priority data. Further, to guarantee a minimum acceptable level of video quality, additional intra-refresh macro-blocks reduce the effect of temporal error propagation.

Adaptive rateless coding for IPTV over a mobile WiMAX channel

As intelligent content management of IPTV moves popular material nearer to the end-user, application-layer channel coding schemes, involving retransmission of extra redundant data, become attractive. Application-layer, adaptive rateless channel coding is exploited in this papers scheme to reconstruct streamed video across an IEEE 802.16e (mobile WiMAX) channel. The paper concentrates on the trade-offs in implementing the scheme, showing that exact calculation of the redundant data has the potential to reduce the forward error correction bit-rate overhead. To reduce delay an appropriate compression rate should also be selected.

Robust IPTV delivery with adaptive rateless coding over a mobile WiMAX channel

As intelligent content management of IPTV moves popular material nearer to the end-user, application-layer channel coding schemes, involving the retransmission of extra redundant data, become attractive as a result of the reduced latency. Applicationlayer, adaptive rateless channel coding is exploited in this papers scheme to reconstruct streamed video across an IEEE 802.16e (mobile WiMAX) channel. The paper concentrates on the trade-offs in implementing the scheme, showing that exact calculation of the redundant data has the potential to reduce the forward error correction bit-rate overhead. To reduce delay, an appropriate compression rate should also be selected.

Effective Video Transport over WiMAX with Data Partitioning and Rateless Coding

Video streaming is anticipated to be a key application of broadband wireless access networks such as WiMAX. This paper proposes a combination of data-partitioning of compressed video information and rateless channel coding to ensure effective video transport. A counter-intuitive result is that comparatively improved objective video quality occurs even though privileged application-layer forward error correction is not given to high priority data. Instead a flat channel coding is used across the data partitions. The scheme results in a lower number of dropped packets at the transmitter buffer and/or a reduced number of packets corrupted by channel noise compared to simple slicing or no frame slicing at all. Larger-sized IEEE 802.16 (WiMAX) Time Division Duplex frames are found to reduce the number of packets dropped through traffic congestion.