Android RIL architecture

http://www.netmite.com/android/mydroid/development/pdk/docs/telephony.html
http://miox.cc/2009/07/android-gsmrildresponse.html
http://miox.cc/2009/07/android-gsmrildrequest.html
http://miox.cc/2009/07/android-gsmrild.html
http://www.linuxidc.com/Linux/2011-12/48954.htm



The function includes solicited and unsolicited functions:

solicited(app->modem):
* SIM PIN, IO, and IMSI/IMEI (11)
* Call status and handling (dial, answer, mute…) (16)
* Network status query (4)
* Network setting (barring, forwarding, selection…) (12)
* SMS (3)
* PDP connection (4)
* Power and reset (2)
* Supplementary Services (5)
* Vendor defined and support (4)




unsolicited(modem->app):
* Network status changed (4)
* New SMS notify (3)
* New USSD notify (2)
* Signal strength or time changed (2)





[Note] android/hardware/ril/libril/ril_commands.h
[Note] AP, app, application processor
[Note] BP, modem, baseband processor