Mandatory standards supported by 3G and 3GPP in mobiles

Should a 3G mobile handset support GSM and WCDMA. tri bands.
The classification 2G 3G DEPENDS ON DATA RATE.
ALSO
In 3GPP LTE is it mandatory that mobiles should be able to switch between GSM AND CDMA NETWORKS.FOR INTEROPERABILITY.


thanks and regards
GV

This is not mandatory, it's depend on vendors and phone model. Many phones can support 2G, 3G and Wi-Fi at the same time.

so you mean to say in LTE it is not mandatory. It can be a standalone GSM or WCDMA , not that it should support both
I know in 3G it is not manadatory.

Regards
GV

At least now LTE shall co-exist with other standards (GSM/GPRS and WCDMA/CDMA-EVDO) and should support them where LTE coverage is unavailable.