How to make VoLTE device Part-1

hmmm  I am fortunately working on VoLTE related project for a while.

It's challenging but something new is there for a change.

I simply like GOOGLE, the way they have opened new ways to communicate , make application to people.

TECHNOLOGY is all about sharing.....we can patent things to get monetary benefits, but its very important to keep sharing things, at least which are already there. If we all keep our learning's to ourselves w.r.t to anything ( food, dance , sports) how will we as humans can progress.



Since , I am a modem eng , a lot of things will be from that perspective. Also lots of thing will not be CORRECT :)  , since I myself is learning at the same time, but I have the luxury of devices to test any changes and practically see how things are working.


We will need
1) One  IMS Stack
2) One TCP-IP Stack   ( there is open-source IwIP) TCP stack present, but I am not sure how to use it . ( I am more working as a GUY who make things work, without owning any module)
3) AT CMD Stack or some Other Communication Layer
4) Voice Engine
5) Device which can talk to network , so that our IP packets can be exchanged with Network.
6) CALL application


Now device here can be modem (baseband processor), as I am working on that only.

I will check for any open-source application or processor , which will have IMS stack and CALL app jointly. I will also be checking with application side team to see how to implement their side


So we have to

1) make connection with network to exchange , RTP/RTCP/SIP packets.
 
    Two connection will be needed and are best for easy implementation.
    One over which we will send SIP packets (DEFAULT BEARER)
    One over which we will send RTP/RTCP packets. (DEDICATED BEARER)

2) IMS stack will setup DEFAULT BEARER with Network.

3) When CALL is triggered, IMS stack will send SIP messages.

4) Network will setup DEDICATED BEARER.

5) Once CALL is connected , then RTP/RTCP packets will come to TCP/IP stack.

6) TCP/IP will send AMR packets to VCE.