Omneya Issa

Performance Evaluation of TV Over Broadband Wireless Access Networks

Worldwide Interoperability for Microwave Access is an emerging wireless access networks offering high data rates and good range. These features, in addition to moderate installation and maintenance costs, make it an appealing last-mile delivery network for IPTV and video applications, especially, in rural regions. However, TV/video delivery must be designed with respect to network characteristics in different environmental conditions. This paper studies the possibility of providing TV and video over the downlink and uplink of this fixed broadband wireless access network without compromising the video quality. The downlink scenario typically corresponds to offering high and standard definition IPTV to customer set-top box, whereas the uplink scenario can be for video surveillance or camera live broadcast. Measurements were taken using professional IPTV and video streaming equipments on commercial IEEE 802.16d system. Analysis was done for different video settings and network configurations in order to characterize network performance and identify video quality in different attenuation and interference conditions. A key outcome of this analysis was the feasibility of TV/video delivery over broadband wireless access networks with good quality of experience provided that system limitations are respected.

Estimation of time varying QoE for high definition IPTV distribution

High Definition (HD) content delivery over IP networks is now a reality in the entertainment marketplace. Such networks can suffer packet loss, especially on the last mile link. This results in time-variant video quality. In this paper we first present an analysis of the human perception of network impairment on HD IPTV quality. Second, we propose a method, based on common objective measurements, to estimate subjective judgments of time-variant quality. A testbed was deployed to emulate a real use case of delivering high definition TV material over an IPTV network. The quality of the delivered H.264/AVC encoded video was evaluated objectively in an emulated environment where packet loss impairments were generated. Objective measurements were then compared to continuous subjective quality ratings. Based on the obtained results, highly correlated models were developed for the estimation of instantaneous user judgment of impaired HD broadcast IPTV.

Quality Assessment of Video Content for HD IPTV Applications

In the last few years, Internet Protocol Television (IPTV) has emerged as one of the major distribution technologies for broadband multimedia services. However, the delivery of High Definition Television (HDTV) services over IP networks still faces many challenges. This paper presents a study on quality assessment of HD video content for IPTV applications. Video sequences with different content types are delivered through an IPTV testbed. Subject to packet loss, their quality is evaluated with common objective video quality measurement tools in the emulated error-prone environment with respect to their content complexity. Objective criticality based on the calculation of spatio-temporal activities is examined to validate its suitability as video content complexity indicator in quality assessment. Subjective assessment is further carried out to validate the objective test results. With a good correlation between subjective Mean Opinion Score (MOS) and objective metrics, the prediction of viewer satisfaction in terms of HD video content quality in IPTV networks becomes feasible. Suggestions are also made regarding the choice of suitable measurements for more meaningful HD content classifications.

Quality assessment of High Definition TV distribution over IP networks

High Definition (HD) content delivery over IP networks has become a reality in the market of entertainment technologies. This paper presents a professional testbed deployed to emulate a real use case of delivering high definition TV material over an IPTV network. The quality of the delivered H.264/AVC encoded video was evaluated by common objective video quality assessment tools in emulated environment subject to impairments. Objective measurements were further validated by subjective tests. Based on the obtained results, guidelines were drawn for the prediction of user perceived quality in loss-prone environments and on the user perception tolerance for viewing impaired HD broadcast IPTV.

Evaluation of H.264/AVC error resilience in HD IPTV applications

The delivery of High Definition Television (HDTV) over IP networks, namely the HD IPTV, has emerged as one of the major distribution and access techniques for broadband multimedia services. IPTV adopts H.264/AVC as its coding standard due to its high video compression efficiency as well as powerful error resilience features. This paper presents studies on some of these features applied to HD IPTV applications. A test system is deployed to simulate the delivery of HD video over a DSL based IPTV network. Effects of error resilience of slicing and Instantaneous Decoding Refreshing (IDR) features on video quality are examined in both channel non-impaired and channel impaired with burst noise circumstances. Based on the acquired results, optimal slice size was obtained for HD video transmission over an impaired channel. The quality of experience related to the IDR interval in combating error propagation was also characterized.

H.264 error resilience adaptation to IPTV applications

TV delivery over IP networks (i.e. IPTV) has emerged as one of the major distribution and access techniques for broadband multimedia services. IPTV adopts H.264 as its coding standard due to its high video compression efficiency as well as powerful error resilience features. This paper presents studies on some of the H.264/AVC error resilience features applied to IPTV applications, namely, high definition (i.e., HD IPTV) and wireless/handheld extension. Test systems are deployed to simulate: (1) The delivery of lower resolution TV programs over wireless channels; (2) The delivery of HD video over an xDSL based IPTV network. Flexible Macroblock Ordering (FMO) slice grouping is assessed in handheld IPTV applications. Optimal slice size is obtained for HD video transmission over impaired channels. The quality of experience related to the Instantaneous Decoding Refreshing (IDR) interval is characterized for HD IPTV.

New method for concealing entirely lost frames in H.264 video transmission over wireless networks

This paper proposes a new error concealment method in which an improved bidirectional motion copy method is developed to conceal entire frames lost in video transmission. Also an overlapped block motion compensation technique is employed to reduce blocking artifacts in the concealed frames. The simulation results show that the proposed method can achieve a PSNR of 2.21dB higher than the conventional motion copy method and of up to 2.56dB higher than conventional motion vector extrapolation methods.

Spectrum Access Quality for Mobile Broadband Video Communications in Smart Cities

Cities use broadband wireless spectrum access technologies to enable a wide range of smart city applications that enhance safety and security, improve efficiency of municipal services and promote a better quality of life for residents and visitors. The most quality and bandwidth-demanding smart city scenarios usually involve video communications. New compression technologies have made the delivery of high-resolution video over access networks a reality. However, video delivery must take into account network characteristics in different environmental conditions. This paper studies the possibility of providing high resolution video in mobile environments over the downlink and uplink of a broadband wireless access network, without compromising the video quality. The downlink scenario typically corresponds to offering multicast/unicast video to mobile residents and visitors, whereas the uplink scenario can be for video surveillance for public safety and electronic news gathering. For this study, measurements were obtained using professional video streaming equipment, on a commercially available broadband wireless access system in a typical emulated mobile environment. Analysis was done for different video settings and spectrum and network configurations in order to characterize network performance and assess video quality in different conditions. A key outcome of this analysis was to determine the feasibility of high resolution video delivery over broadband wireless access networks in mobile conditions and to point recommendations for the QoE optimization of mobile video reception. A good quality of experience is possible provided that system and environment limitations are respected.

New algorithm for motion vector extrapolation for concealing entire frame loss in the H.264 video receiver

A new motion vector extrapolation (MVE) algorithm is proposed to conceal an entire frame loss in low-bit-rate video transmission. The simulation results show that the proposed method provides better video quality at the decoder than existing MVE methods when concealing an entire frame loss.

WiMAX TV: Possibilities and Challenges

WiMAX is an emerging wireless access network offering high data rates and good coverage range. This makes it an appealing last-mile delivery network for IPTV and video applications. However, TV/video delivery must be designed with respect to WiMAX characteristics in different environmental conditions. This paper studies the possibility of providing TV and video over the downlink and uplink of a Fixed WiMAX network without compromising the user perceived video quality. Measurements were taken using professional IPTV and video streaming equipments on commercial IEEE 802.16d equipment. Analysis was done for different video settings and network configurations. A key outcome of this analysis was the feasibility of TV/video delivery over WiMAX with good quality of user experience provided that system limitations are respected.