Open Access

Protection of Video Packets over a Wireless Rayleigh Fading Link: FEC versus ARQ

  • Julie Neckebroek1Email author,
  • Frederik Vanhaverbeke1,
  • Danny De Vleeschauwer1 and
  • Marc Moeneclaey1
EURASIP Journal on Advances in Signal Processing20082008:852697

https://doi.org/10.1155/2008/852697

Received: 1 October 2007

Accepted: 8 May 2008

Published: 28 May 2008

Abstract

Video content can be provided to an end user by transmitting video data as a sequence of internet protocol (IP) packets over the network. When the network contains a wireless link, packet erasures occur because of occasional deep fades. In order to maintain a sufficient video quality at the end user, video packets must be protected against erasures by means of a suitable form of error control. In this contribution, we investigate two types of error control: (1) forward error correction (FEC), which involves the transmission of parity packets that enables recovery of a limited number of erased video packets, and (2) the use of an automatic repeat request (ARQ) protocol, where the receiver requests the retransmission of video packets that have been erased. We point out that FEC and ARQ considerably reduce the probability of unrecoverable packet loss, because both error control techniques provide a diversity gain, as compared to the case where no protection against erasures is applied. We derive a simple analytical expression for the diversity gain resulting from FEC or ARQ, in terms of the channel coherence time, the allowable latency, and (for FEC) the allowable overhead or (for ARQ) the time interval between (re)transmissions of copies of a same packet. In the case of HDTV transmission over a 60 GHz indoor wireless link, ARQ happens to outperform FEC.

Publisher note

To access the full article, please see PDF.

Authors’ Affiliations

(1)
Department of Telecommunications and Information Processing (TELIN), Ghent University

Copyright

© Julie Neckebroek et al. 2008

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.