Short list of things which need to be done
- SIM
    - change pin
    - disable/enable pin
- Call
    - Forward
    - Halt
    - Conference
    - Dtmf
    - Transfer
    - Join
    - Emergency
- Network
    - ListProviders
    - RegisterWithProvider
    - Forwarding
    - Identification
    - USSD
- SMS
    - SendMessage
    - RetrieveMessage from SIM
    - Notify incomming messages
- Phonebook
    - Retrieve emergency numbers
- PDP
- CB
- Monitor
- HZ
