Content for TR 43.903 Word version: 18.0.0
5 Overview
6 Study Results, User Plane
7 Study Results, Control Plane
8 Informative: Network Design Issues
9 Expected impacts to existing specifications
10 Summary and Conclusion
$ Change History
5 Overview p. 10
5.1 Background p. 10
5.2 Architecture p. 11
5.2.1 Legacy Architecture p. 11
5.2.2 PCM encoded speech (G.711) over IP p. 12
5.2.3 Compressed speech over IP p. 13
5.2.4 Example Deployment Scenarios p. 15
5.3 Functional Impacts p. 19
6 Study Results, User Plane p. 20
6.1 User Plane Principles p. 20
6.1.1 Transport network User Plane for A over IP p. 20
6.1.2 Transport network Control Plane for A over IP p. 21
6.1.3 Potential impact on the Nb and Nc interfaces p. 21
6.2 Payload Formats p. 21
6.2.1 Existing TRAU Frames for Speech p. 21
6.2.2 RTP profiles for speech p. 25
6.2.2.1 RTP profiles for G.711 encoded speech on the A over IP interface p. 25
6.2.2.2 RTP profiles for compressed speech on the A over IP p. 25
6.2.2.3 RTP profiles for compressed speech on Nb interface p. 26
6.2.3 RTP profiles for data and fax calls p. 26
6.3 Transport Layer p. 27
6.3.1 Link Layer and Physical Layer p. 27
6.3.2 UDP and IP p. 27
6.3.3 RTP p. 27
6.3.4 RTCP p. 27
6.3.5 IP Multiplexing p. 27
6.4 Handover Procedure (User Plane) p. 28
6.4.1 Alternative 1 p. 28
6.4.1.1 General Handover Procedure p. 28
6.4.1.2 Intra-BSC Handover to a compatible target cell p. 28
6.4.1.3 Intra-BSC Handover to an incompatible target cell p. 28
6.4.1.4 Inter-BSC Handover p. 28
6.4.2 Alternative 2 p. 28
6.5 Time Alignment p. 28
6.5.1 Introduction p. 28
6.5.2 Time Alignment principles p. 29
6.5.3 Time Alignment performances evaluation p. 30
6.5.4 Proposed implementation p. 31
6.5.5 Summary p. 32
7 Study Results, Control Plane p. 33
7.1 Control Plane Principles p. 33
7.1.1 Exchange of Transport Layer Information p. 33
7.1.2 Need for a Call Identifier for IP-based calls p. 34
7.1.3 Exchange of Codec Information p. 35
7.1.3.1 Exchange of Codec Information at Call Establishment p. 35
7.1.3.2 Exchange of Codec Information at Handover p. 37
7.1.4 Location of Transcoder Resource in BSS or CN p. 38
7.1.5 Exchange of RTP Parameters p. 38
7.2 Signalling Messages p. 40
7.2.1 BSSMAP p. 40
7.2.1.1 Assignment Request p. 40
7.2.1.2 Assignment Complete p. 40
7.2.1.3 Handover Required p. 41
7.2.1.4 Handover Request p. 42
7.2.1.5 Handover Request Acknowledge p. 43
7.2.1.6 Handover Performed p. 43
7.2.1.7 Complete Layer 3 Information p. 44
7.2.1.8 BSC-SCL and MSC-PCL p. 44
7.2.1.9 Speech Codec (Chosen) p. 45
7.2.1.10 Speech Codec (Used) p. 45
7.2.1.11 Circuit Switched Data Codec (CSD Dummy Codec) p. 45
7.2.2 DTAP p. 46
7.2.3 VGCS/VBS Protocol p. 46
7.2.4 H.248 Protocol p. 46
7.3 Procedures p. 46
7.3.1 Codec Negotiation at Call Setup p. 46
7.3.2 Codec Negotiation at Handover p. 48
7.3.2.1 Intra-BSC Handover to a Compatible Target Cell p. 49
7.3.2.2 Intra-BSC Handover to an Incompatible Target Cell p. 49
7.3.2.3 Inter-BSC Handover p. 52
7.3.3 Codec Re-Negotiation after Inter-BSC Handover p. 54
7.4 Impacts on the A Interface Control Plane p. 56
8 Informative: Network Design Issues p. 60
8.1 Solution 1 p. 60
8.2 Solution 2 p. 60
9 Expected impacts to existing specifications p. 60
10 Summary and Conclusion p. 60
$ Change History p. 62
