about FSK data question....

Dear all :
In FSK close loop direct Frequency modulation ,
1.data rate is higher than loop BWor lower than loop BW ?
2.And what's the relation between data rate and Loop BW ?

Thanks .

In close loop FSK modulation, you can push two circuit - xosc or vco
for push vco, the data rate should higher than loopbandwidth
for push xosc, that data rate should lower than loopbandwidth

謝謝大大講解
不過Data rate 跟 BW 要多少比例呢 ?
我記的以前聽說要10:1事不是這樣 ?
THANKS