  This paper presents a reliable and efficient high quality video streaming
solution for use in challenging outdoor environments over Wi-Fi. An application
layer forward error correction based on RaptorQ codes was implemented in a
practical Wi-Fi based server and client system to enhance reliability. Thus,
this paper presents the first detailed analysis on the implementation of
RaptorQ codes for streaming high definition video over Wi-Fi. The measurements
were performed in central Bristol with parameters such as RaptorQ symbol size,
code rate, buffering time and modulation and coding scheme, and user quality of
experience based on these parameters was evaluated. For multicast live video
streaming it is demonstrated that system performance is mostly dominated by
hardware and software limitations on constrained host platforms where the
incoming packet rate exceeds the device`s ability to consume the traffic, i.e.,
Wi-Fi clients are a major source of packet loss, even in ideal channel
conditions. Client limitations were found to be a function of modulation and
coding schemes and RaptorQ coding parameters. Therefore, the optimum system
design parameters such as RaptorQ symbol size, code rate and buffering time
with respect to modulation and coding schemes were suggested considering
practical limitations from real-world measurements.
