Robust Video Transmission Over Wireless LANs

Abstract

Abstract-Home wireless networks are mainly used for data transmission; however, they are now being used in video delivery applications, such as video on demand or wireless internet protocol (IP) television. Off-the-shelf technologies are inappropriate for the delivery of real-time video. In this paper, a packetization method is presented for robust H.264 video transmission over the IEEE 802.11 wireless local area network (WLAN) configured as a wireless home network. To overcome the poor throughput efficiency of the IEEE 802.11 Medium Access Control (MAC), an aggregation scheme with a recovery mechanism is deployed and evaluated via simulation. The scheme maps several IP packets (each containing a single H.264 video packet called a Network Abstraction Layer (NAL) unit) into a single larger MAC frame. Video robustness is enhanced by using small NAL units and by retrieving possible error-free IP packets from the received MAC frame. The required modifications to the legacy MAC are described. Results in terms of throughput efficiency and peak-signal-to-noise ratio (PSNR) are presented for the case of broadcast and real-time transmission applications. Compared to the legacy case, an 80% improvement in throughput efficiency is achieved for a similar PSNR video performance. For fixed physical layer resources, our system provides a 2.5-dB gain in video performance over the legacy case for a similar throughput efficiency. The proposed solution provides considerable robustness enhancement for video transmission over IEEE 802.11-based WLANs.Index Terms-Medium Access Control (MAC), packetization, peaksignal-to-noise ratio (PSNR), video transmission, wireless local area networks (WLANs).

Engineering wireless broadband access to IPTV

“…In [28] a packetization method was presented for robust H.264 video transmission over an IEEE 802.11 wireless local area network (WLAN) configured as home network. Video robustness is enhanced by using small NAL units and by retrieving possible error-free IP packets from the received MAC frame.…”

H.264 video streaming with data-partitioning and Growth codes

“…There is minimal overhead as CRCs are already part of the existing NAL scheme [1] and uniform Rateless coding (though not Growth codes) has already been applied to multimedia over wireless. For video streaming over an ADSL channel, the advantages of this variation upon AL-FEC may well be considerable owing to the longer error bursts.…”

“…While research has investigated NALUs packetization issues [1], data partitioning (DP) of NAL units into A, B, and C types [2] of decreasing priority for error resilience purposes deserves attention. In this paper, we additionally apply application-layer Forward Error Correction (AL-FEC) to Unequal Error Protection (UEP) of data-partitioned NALUs by means of rateless channel codes for multicast delivery.…”

A video error resilience redundant slices algorithm and its performance relative to other fixed redundancy schemes

“…The necessary transmission of one PPS for each redundant picture adds an overhead of 16 kbits/s, regardless of the redundancy level chosen. We assume that all PPSs are received correctly given that they are very small in size (only a few bytes) and short packets are unlikely to be corrupted in wireless transmission [18]. (Table): (a) average actual frame PSNR vs. estimated frame PSNR for a 10% PER; (b) average actual sequence PSNR with PFC and AEC concealment vs. estimated sequence PSNR for a number of packet error rates.…”