Android APIs
Added in API level 1
package

android.telephony.gsm

Provides APIs for utilizing GSM-specific telephony features, such as text/data/PDU SMS messages.

Classes

GsmCellLocation Represents the cell location on a GSM phone. 
SmsManager This class was deprecated in API level 4. Replaced by android.telephony.SmsManager that supports both GSM and CDMA.  
SmsMessage This class was deprecated in API level 4. Replaced by android.telephony.SmsMessage that supports both GSM and CDMA.  
SmsMessage.SubmitPdu This class was deprecated in API level 4. Use android.telephony.SmsMessage.  

Enums

SmsMessage.MessageClass This enum was deprecated in API level 4. Use android.telephony.SmsMessage.