VP9 and simulcast

[JeffMan (Jeff)]

encodings   :
                    [
                        { rid: 'r0', scalabilityMode: 'S1T3', maxFramerate: fps },
                        { rid: 'r1', scalabilityMode: 'S1T3', maxFramerate: fps },
                        { rid: 'r2', scalabilityMode: 'S1T3', maxFramerate: fps }
                    ],

I thought VP9 supported Simulcast. What am I doing wrong?