How to publish multiple bit rate(MBR) live video?

Question

I've searched quite a few threads:

http://www.developsigner.com/blog/2009/05/28/multi-bitrate-live-streaming-with-fmle-adobe-flash-media-live-encoder

http://forums.adobe.com/thread/27371

dynamicStream.addStream("livestream1",200);
dynamicStream.addStream("livestream2",400);
dynamicStream.addStream("livestream2",600);


vid.play2(dynamicStream);

But all of them are talking about playing multiple bit rate live video,

my question is how I can publish multiple bit rate live videos in the first place?