1、TIA DOCUMENT Circuit Switched Video Conferencing Services TIA-926 DECEMBER 2002 TELECOMMUNICATIONS INDUSTRY ASSOCIATION The Telecornmunicalions Industry Assodalion represents lhe cornmunicalions mor o Electrcriic Industries Alliance NOTICE TIA Engineering Standards and Publications are designed to s
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6、Description 31 23. TS 26.110 Codec for Circuit switched Multimedia Telephony Service; General 32 Description (Version 5.0.0), June 2002 33 24. TS 26.111 Codec for Circuit switched Multimedia Telephony Service; 34 Modifications to H.324 (version 5.0.0), June 2002 1-2 TIA-926 I 1.3. Abbreviations z Fo
7、r the purpose of this document, the following abbreviations apply: 3 3G Third Generation system 3GPP2 3GPP-324M Terminal compliant with 23, 241 BLOB BLock Of Bits. Third Generation Partnership Project 2 Mobile Station for 3GPP Circuit-Switched Video Conferencing BS BSAP 10s 10s Al 10s A2 Base Statio
8、n. A fixed station used for communicating with mobile stations. Depending upon the context, the term base station may refer to a cell, a sector within a cell, or other part of the wireless system. Base Station Application Part. The application layer signaling protocol that provides messaging to acco
9、mplish the functions of the 10s Al Interface component of the MSC-BS Interface. Inter-Operability Specification for interfaces between an MSC and a BS (see i). The 10s interface that carries signaling information between the Call Control (CC) and Mobility Management (MM) functions of the MSC and the
10、 call control component of the BS (BSC). The 10s interface that carries 64/56 kbps PCM information (voice/data) between the Switch component of the MSC and the Selection/Distribution Unit (SDU) function of the BS (BSC). ISUP ISDN User Part IWF Interworking Function. In this document, this refers spe
11、cifically to the interworking between different speech codecs (e.g., EVRC and 3GPP-AMR). Mobile Station A station in the Public Cellular Radio Telecommunications Service intended to be used while in motion or during halts at unspecified points. Mobile stations include portable units (e.g., hand-held
12、 personal units) and units installed in vehicles. MS MSC QOS QoS BLOB Mobile Station Mobile Switching Center Quality of Service. The set of parameters and procedures associated with a service indicating the capabilities and constraints related to the delivery of the service. The set of QoS parameter
13、s exchanged via cdma2000 signaling that defines the QoS context for a particular service instance. 1-3 TIA-926 RC RLP RLP-BLOB Radio Configuration. A set of Forward Traffic Channel and Reverse Traffic Channel transmission formats that are characterized by physical layer parameters such as transmissi
14、on rates, modulation characteristics, and spreading rate. Radio Link Protocol The set of RLP parameters that defines the RLP configuration (e.g., retransmission scheme, round trip time) 1-4 TIA-926 I 2. OVERVIEW OF VIDEO CONFERENCING SERVICES 2 2.1. General Descriptions 3 4 Service options 57 and 58
15、 provide video conferencing services capable of 5 transferring multiplex audio, video and control data at speeds of 32 and 64 kbps 6 respectively, over the air-interface (Um) between mobile stations and other 7 terminals. 8 9 10 11 and ISUP signaling. 12 13 14 15 16 17 18 19 The document defines poi
16、nt-to-point video conferencing services. Service options 57 and 58 use the Radio Link Protocol defined in 101 to provide an octet stream transport service over forward and reverse traffic channels. The MSC provides the protocol conversion between cdma2000 upper layer signaling Above the Radio Link P
17、rotocol, the ITU-T H.324 21 group of protocols is used for the video conferencing service. ITU-T H.245 is used for conducting capability exchange and negotiations between the terminals, and for opening and closing of logical channels and other components of the video conferencing services. ITU-T H.2
18、23 16, 17, 181 is used for multiplexing/demultiplexing video, audio and control data. The NSRP and CCSRL protocols defined in Annex C of ITU-T H.324 are used to transport the H.245 control messages reliably over the H.223 multiplex layer. Interoperability with other networks, such as the 3GPP networ
19、k, is provided. 20 21 The mobile station uses the encoders and decoders, and multiplexer specified in 22 section 4. Input/output (I/O) interfaces for video, audio, and system control 23 provided in the mobile station are out of scope of this specification. 24 The sending function in the mobile stati
20、on encodes the data from each media source 25 with the corresponding visual and audio encoder. The output of the encoders and 26 the system control interface are multiplexed and sent to transport layer of the 27 underlying wireless network. 28 The receiving function in the mobile station de-multiple
21、xes the received data stream, 29 and decodes the data with the corresponding video and audio decoders. The output 30 is then sent to be played at local visual and audio players (see Figure 1). 31 After the Um interface has been established, control messages defined in 19 are 32 used for video confer
22、encing call setup procedures and for controlling other 33 components specified in section 4. 2.2. Structure of the Video Conferencing Service System in the MS 2- I TIA-926 1 2 3 4 5 6 7 8 9 10 11 12 13 14 e of video Conferencing Figure 2- 1 Scope and Structure of Circuit-Switched Video Conferencing
23、Services 2.3. Video Conferenchg Service Protocol Stack Reference Model The video conferencing service architecture is defined by the protocols used across the different interface points. Figure 2-2 depicts the video conferencing service protocol stack for establishing the required bearer on the cdma
24、2000 wireless link. Mobile Station Base Station MSC Figure 2-2 cdma2000 Bearer Call Setup Protocol Stack Figure 2-3 depicts the protocol stack for the video conferencing bearer after establishing the cdma2000 wireless link. 2-2 TIA-926 11.223 frame R1.P cdma20 Mobile Station _. i Rate Adaptation Pro
25、tocol i L- R1.P 64/56 kbps PCM 64/56kbps PCM Physical Physical cdma2 Um A2 Base Station MSC 1 2 3 4 10 11 Figure 2-3 Video Conferencing Call Setup and Bearer Protocol Stack The cdma2000 Layer 1, Layer 2, and signaling protocols between the MS and the BS in Figure 2-2 and Figure 2-3 are described in
26、3, 4, 5, 6, 7, and 8. The 3G 10s Al interface is used for signaling information for cdma2000 call setup as specified in i. The 3G 10s A2 interface is used for H.324 video conferencing call setup and the video conferencing bearer as specified in 181. For the 32 kbps video service, the BS performs rat
27、e adaptation between the data stream carried over the RLP transport layer and the 64/56 kbps PCM link on the A2 interface. 2-3 TIA-926 (This Page Intentionally Left Blank) 2-4 TIA-926 1 2 8 9 10 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 3. UM INTERFACE REQUIREMENTS FOR ESTABLISHHING THE VIDEO
28、CONFERENCING BEARER The MS and the BS shall support the physical layer, multiplex sublayer, radio link management, and call control protocols as defined in 3, 4, 5, 6, 7, and 8. The H.223 frames carrying multiplexed H.245 call control messages, video data, and voice data shall be sent over RLP at a
29、maximum rate of 32 kbps for service option 57, and at a maximum rate of 64 kbps for service option 58. The BS shall construct RLP frames carrying a user data rate of 32 or 64 kbps from a single channel of 64/56 kbps PCM received from the MSC. 3.1. RLP Requirements At the Um interface, the MS and the
30、 BS shall use Radio Link Protocol Type 3 as defined in lo. In this specification, Radio Link Protocol Type 3 will be called simply RLP. To control the reliability and delay provided by RLP, the BS uses the RLP-BLOB defined in 101 to send the RLP retransmission scheme to the MS. 3.2. Initialization a
31、nd Connection of Video Conferencing Service Options The MS shall support service options 57 and 58. options 57 and 58. The MS shall initiate the connection of the video conferencing service by requesting service option 57 or 58 in either a Page Response Message, Origination Message, or an Enhanced O
32、rigination Message as defined in 7. If the BS receives a Paging Request Message for a video conferencing call from the MSC, the BS shall page the specific MS with the identified video conferencing service option. The BS should support service 3.2.1. Mobile Station Procedures The MS shall connect the
33、 video conferencing service using the procedures defined in 7. If service negotiation is required the MS shall perform the service negotiation procedures defined in 71. The MS shall not propose or accept a service configuration whose attributes are inconsistent with the valid service configuration a
34、ttribute table for service options 57 and 58 as shown in Table 1 . The default service configuration for video conferencing service options 57 and 58 shall be as shown in Table 1 . 3- I TIA-926 1 Table 1 Valid Service Configuration Attributes for Service Options 57 and 58 Service Configuration Attri
35、bute Forward FCH/DCCH Multiplex Option Reverse FCH/DCCH Multiplex Option Forward FCH/DCCH Transmission Rates Reverse FCH/DCCH Transmission Rates Forward Traffic Type Reverse Traffic Type Forward FCH/DCCH Radio Configuration Reverse FCH/DCCH Radio Configuration Forward Supplemental Channel Multiplex
36、Option Reverse Supplemental Channel Multiplex Option Forward Supplemental Channel Frame Length Reverse Supplemental Channel Frame Length Forward Supplemental Radio Configuration Reverse supplemental Radio Configuration Valid Selections ox 1 ox 1 For the FCH, Rates 1, 1/2, 1/4, and 1/8 enabled. For t
37、he DCCH, Rate 1 enabled, Rates 1/2, 1/4, and 1/8 not enabled. For the FCH, Rates 1, 1/2, 1/4, and 1/8 enabled. For the DCCH, Rate 1 enabled, Rates 1/2, 1/4, and 1/8 not enabled. Primary or Secondary Primary or Secondary RC 3, 4, 6, 7 RC3,5 Oxf20 Oxf20 20 ms 20 ms RC 3, 4, 6, 7 RC3,5 where multiple o
38、ptions are supported the default is in bold 2 3 3.2.2. Base Station Procedures 4 5 6 defined in 7. The BS shall connect the video conferencing service using the procedures defined in 7. If service negotiation is required the BS shall perform the service negotiation procedures 3-2 TIA-926 9 10 11 12
39、13 14 15 16 17 18 19 20 21 22 The BS shall not propose or accept a service configuration whose attributes are inconsistent with the valid service configuration attribute table for service options 57 and 58 as shown in Table 1 . The default service configuration for video conferencing service options
40、 57 and 58 shall be as shown in Table 1 . The BS shall assign Forward and Reverse Supplemental channels to constantly deliver a user data rate of at least 32 or 64kbps over the Supplemental channel. Variable supplemental channel rate operation below 32 and 64 kbps shall not be allowed for service op
41、tions 57 and 58, respectively. 3.2.3. Traffic Channel Handoff Following a CDMA-to-CDMA hard handoff (see 7) involving transitions between disjoint sets of BS/MSCs or a frequency change, RLP shall be immediately initialized according to the initialization procedures described in 1 O. 3.3. Quality of
42、Service (QoS) 3.3.1. QoS Parameters The set of QoS parameters that apply to service options 57 and 58 are defined in Table 2. For each QoS parameter in Table 2, the set of allowable values that can be selected by service options 57 and 58 are defined. If a parameter value is not specified in Table 2
43、, it shall be considered reserved and it shall not be used. For service options 57 and 58, QoS parameters shall be identical for the forward and reverse links. Table 2 QoS Parameters Applicable to Service Options 57 and 58 I QOS Parameter I SO I Allowable Value(s) I 3-3 TIA-926 Assured Mode Forward
44、Link Priority Reverse Link Priority Forward Link Minimum User Data Rate Reverse Link Minimum User Data Rate Forward Link Data Loss Rate Reverse Link Data Loss Ratel Forward Link Maximum Delay Reverse Link Maximum Delay2 57, 58 57, 58 57 58 57, 58 57, 58 Assured mode service. This is the default valu
45、e. The users priority should not be reduced. 32 kbps. This is the default value. 64 kbps. This is the default value There are no specific values defined for this parameter. Both the MS and BS should provide appropriate FER for this service. There are no specific values defined for this parameter. Bo
46、th the mobile station and base station should provide the minimum amount of delay for this service. 1 2 3 4 5 6 7 8 9 10 11 12 13 In Table 2 the data loss rate is the error rate provided above the RLP layer. The maximum delay is defined as the amount of time user data can be held in the transmit que
47、ue (Le., from the moment it is submitted to RLP for transmission until its actual transmission on a physical channel). 3.3.2. Mobile Station Procedures for QoS The MS shall use the default set of QoS parameters as defined in Table 2 for service options 57 and 58. As there is only one set of default
48、parameters, there is no MS QoS BLOB defined for service options 57 and 58. 3.3.3. Base Station Procedures for QoS The BS shall use the default set of QoS parameters as defined in Table 2 for service options 57 and 58. The data loss rate is the error rate provided above the RLP layer. Maximum delay i
49、s defined as the amount of time user data can be held in the transmit queue (Le., from the moment it is submitted to RLP for transmission until its actual transmission on a physical channel). 3-4 TIA-926 I z As there is only one set of default parameters, there is no BS QoS BLOB defined for service options 57 and 58. 3-5 TIA-926 (This Page Intentionally Left Blank) 3-6 TIA-926 1 5 6 7 8 9 10 11 12 13 14 15 16 4. VIDEO CONFERENCING SERVICES MULTIMEDIA SYSTEMS ITU-T H.324 recommendation with Annex C
