A method and a system for streaming multi channel digital isochronous data. The method is used for streaming multi channel digital isochronous data, e.g. audio data, in a standard wireless local area network transmission system where bandwidth is reserved for both contention-based traffic and contention free traffic and the audio data formed by samples is organized in audio frames and sent to receivers using multicasting, within consecutive beacon intervals. The contention free traffic of the beacon interval is adjusted to an optimum value, and the length of the beacon interval is adjusted such that a required amount of audio data can be sent to the receivers with minimum system delay.