A Dynamic Forward Error Control Scheme for Video Streaming over Wireless Networks

Wireless networks have dynamic transmission properties as the wireless channel conditions randomly change over time due to several environmental factors. When transmitting real-time applications such as video, the dynamic properties of wireless networks can have detrimental effects on the quality of the video delivered to a user. Many Quality of Service (QoS) guarantee techniques to improve video quality in wireless networks are available. However, these mainly focus on traffic shaping based on bandwidth requirements and prioritization and do not take into account the effects a changing wireless channel might have on the transmitted video. With an increasing amount of video applications being transmitted over wireless networks, alternative methods to provide QoS guarantees should be investigated. This research proposes an adaptive Forward Error Control (FEC) mechanism that dynamically adjusts the number of error control packets based on the traffic load in the network and the state of the wireless channel. When the wireless channel is bad, such as during a rain storm, the proposed mechanism reduces the amount of FEC packets added thereby reducing computational overhead in the network. This enables the receiver to recover the information sent by the transmitter faster with fewer errors than it otherwise would. Simulation results using video trace files show an improvement over existing solutions in terms of the number of FEC packets added while overall the user-perceived quality of the video streaming session is maintained at the same level, even when the network is experiencing a high Packet Error Rate (PER).