What is difference between bsnl 3g data card and 3g sim card?

and what are the speedsWhat is difference between bsnl 3g data card and 3g sim card?
3g Data card allows you access to the data network with your computer via USB, expresscard, or PCMCIA. A sim card, allows a GSM device (can be a data card) to authenticate on that network. CDMA data cards do not require SIM cards. GSM and CMDA (EVDO) are competing technologies.



In CMDA the speeds are (all are TECHNICALLY 3G, even 1x, although most carriers consider 1x to be 2G)

1xRTT: up to 144kbps

EVDO Rev.0: Up to about 700 kbps

EVDO Rev.A: Burst speeds up to 2.5 Mbps