GSM 协议栈设计结构英文(doc 22页)

1 Architecture of GSM
2 CC
2.1 Summary
In GSM protocol, both SS protocol and CC protocol are sub-protocol of CM protocol. The CC entity uses box to communicate with API, MM and RR. Each CC entity shall communicate with the correspondent peer entity using its own MM connection.
2.2 Object Model Diagram
In CC module, different CC context needs interwork with others, so all CC context are organized in a queue. Every CC context will manage a call.
2.3 Objects Description
The functions of CC entity as following:
Call establishment procedures;
Call clearing procedures;
Call information phase procedures;
Miscellaneous procedures.
DTMF manage;
User notification;
In call Modify manage;
CRSS function manage.
2.4 CC State Chart
FSM state CC state Describe
U0 CC_U0 No call exists
U01 CC_U01 MM Connection pending, This state exists for a mobile originating call, when the mobile station requests the establishment of a MM connection.
U1 CC_U1 CC has send SETUP
 CC_U3 CC has received CALL PROCEEDING
 CC_U4 CC has received ALERT
U6 CC_U6 MS has received SETUP
U8 CC_U8 MS has sent CONNECT.
U9 CC_U9 MS has sent CALL CONFIRM
U9 CC_U7 MS has sent ALERTING

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