1 Introduction.........................................................................................8 1.1 Scope.........................................................................................8 1.2 Profile Dependencies..................................................................9 1.3 Symbols and Conventions..........................................................9 1.3.1 Requirement Status Symbols.........................................9 1.3.2 Naming Conventions....................................................10 1.3.3 Signaling Diagram Conventions...................................11 2 Profile Overview................................................................................12 2.1 Protocol Stack...........................................................................12 2.2 Configuration and Roles...........................................................13 2.3 User Requirements and Scenarios...........................................13 2.4 Profile Fundamentals................................................................14 2.5 Conformance............................................................................14 3 Application layer...............................................................................15 4 Hands-Free Control Interoperability Requirements.......................17 4.1 Introduction...............................................................................17 4.2 Service Level Connection Establishment..................................17 4.2.1 Service Level Connection Initialization.........................17 4.2.2 Link Loss Recovery......................................................21 4.3 Service Level Connection Release...........................................21 4.4 Transfer of Registration Status.................................................23 4.5 Transfer of Call and Call Setup Status......................................24 4.6 Audio Connection Setup...........................................................24 4.7 Audio Connection Release.......................................................25 4.8 Answer an Incoming Call..........................................................26 4.8.1 Answer Incoming Call from the HF – In-Band Ringing.26 4.8.2 Answer Incoming Call from the HF – No In-Band Ringing27 4.8.3 Answer Incoming Call from the AG..............................28 4.8.4 Change the In-Band Ring Tone Setting.......................29 4.9 Reject an Incoming Call............................................................30 4.9.1 Reject an Incoming Call from the HF...........................30 4.9.2 Rejection/Interruption of an Incoming Call in the AG....31 4.10 Terminate a Call Process.........................................................32 4.10.1 Terminate a Call Process from the HF.........................32 4.10.2 Terminate a Call Process from the AG.........................33 4.11 Audio Connection Transfer Towards the HF.............................34