电话中的RIL是什么？

Question

Can any one help me out to understand about RIL in telephony.

I did hear RIL word in telephony domain. Can you please let me know what it is exactly.

Answer 1

Radio Interface Layer : It is the bridge between Android phone framework services and the hardware. It consist of :

RIL Daemon :- The RIL Daemon initializes the Vendor RIL, processes all communication from Android telephony services and dispatches calls to the Vendor RIL as solicitated commands. RILD will be initialized during the Android system start up. Each vendor RIL has RIL_Init function.

Vendor RIL :- It is a library specific to each modem. The radio-specific vendor RIL of ril.h that processes all communication with radio hardware and dispatches calls to the RIL Daemon(rild) through unsolicited commands.

Android Telephony framework has one interface file Ril.java which keeps track of each incoming/outgoing request that has been sent/receive to RIL.It basically forms socket connection wih RIL daemon. RIL daemon links framework to vendor Ril.Each mobile vendor will have their own implementation of vendor RIl and available in .so(shared library).The design and implementation of vendor ril depends upon the modem used.

Initialisation :- When power on,phone process starts and android telephony framework is initialized,Framework makes socket connection to ril damon ,the ril damon finds the path of vendor ril library from system properties and loads vendor ril in form of.so library. The vendor ril is first intialized by calling its RIL_INIT method. The ril daemon part of RIL calls RIL_REGISTER to provide reference of each vendor ril functions to the telephony frmaework.

More information:- https://wladimir-tm4pda.github.io/porting/telephony.html https://source.android.com/devices/tech/connect/ril