Annex 1 to AVC-553R

Documents for the Boston/New York meeting (7-16 July 1993)

Normal Documents

AVC number	MPEG93/...	Pur-
pose	Title (source)	
AVC-491b	N400	R	Test Model 5 (Test Model Editing Committee)	
AVC-496R		R	Report of the eleventh meeting in Sydney and Melbourne - March 27 - April 7, 1993 (Chairman)	
AVC-497	???	R	MPEG-2 Working Draft - Video Part - Version 4 (Working Draft Editing Committee)	
AVC-498	-	D	Work plan for broadband audiovisual systems Recommendations (S. Okubo)	
AVC-499	-	R	Report of ITU-TS SG 15 Rapporteru's meeting in Tokyo (N D Kenyon)	
AVC-500	-	P	Multipoint 4 QCIF to CIF video mixing (Bellcore)	
AVC-501	-	I	Simulation studies of 4 QCIF to CIF video mixing (Bellcore)	
AVC-502		R	MPEG 2 Ssytems Working Draft (Systems Committee Adhoc Group)	
AVC-503	493	I	Performance of the Mian Profile @ Main Level - distributive and interactive services (BELGACOM, UCL)	
AVC-504	494	I	MPEG-2|H.26X error resilience based on data partitioning 
(BELGACOM, UCL)	
AVC-505	495	I	New results on spatial scalability ((BELGACOM, UCL)	
AVC-506		P	Concern regarding MPEG-2 Systems and ATM/AAL functionality (Australia)	
AVC-507	567	D	H.32X terminal and MPEG-2 Systems (Aus. UVC)	
AVC-508	568	D	B-ISDN & Video Services Tutorial (S. Dunstan, Siemens)	
AVC-509	516	P	Flexible Object Oriented Decoding Using Slice Identification (Aus. UVC)	
AVC-510	517	I	FF & FR using Frequency Scalability layered coding (Aus. UVC)	
AVC-511	528	I/P	Report of Ad-hoc Group on ATM Cell Loss and Error Resilience 
(M. Biggar, chair)	
AVC-512	-	P	Design of H.32z terminals for LANs (Aus. UVC)	
AVC-513	-	P	H.22z protocol for LANs (Aus. UVC)	
AVC-514	546	P	Time stamp for a large picture (Japan) 	
AVC-515	547	P	Considerations on AC-leaky Prediction (Japan)	
AVC-516	548	D	Considerations on the next profile (Japan)	
AVC-517	549	D	Practical examples of Hierarchical coding (Japan)	
AVC-518	550	P	Syntax modification for compatibility/spatial scalability (Japan)	
AVC-519	551	P	VBV operarion in 3:2 pulldown (Japan)	
AVC-520	552	D	Some considerations on the coding segments (Japan)	
AVC-521	599	P	Correction method for cell loss and bit error in AAL Type 1 (Japan)	
AVC-522	-	I	VBR coding and octet interleave (Japan)	
AVC-523	-	I	Low delay IPB mode transmisssion using VBR (Japan)	
AVC-524	553	D	Relation between MPEG-2 transport mux and ATM/ALL and possible candidates for AAL (Japan)	
AVC-525	514	P	Telecommunication requirements for the Next profile (NL,I,UK,N,FRG)	
AVC-526		D	Telecommunication levels for the Next profile (NL,I,UK,N,FRG)	
AVC-527	545	I	Software decoding of video streams (PTT Research)	
AVC-528	543	I	Inter working between wide screen SCIF and SCIF video conferencing systems (PTT Research)	
AVC-529	561	I	On the B-frame design complexity of spatio-temporal weighting 
(PTT Research)	
AVC-530		P	European stance on leaky prediction (F,FRG,B,N,I,NL,UK)	
AVC-531	639	I	Simulation results on AC-leaky prediction (France)	
AVC-532	638	I	Cell loss resilience : simulation results on concealment techniques (France)	
AVC-533	636	I	Experiment on spatial/temporal H.261/H.26x compatibility (France)	
AVC-534	569	I	Comparison of CTV/HDTV compatible coding schemes (ETRI)	
AVC-535	-	I	Invitation to the 14th ATM Video Coding Meeting (ETRI)	
AVC-536	620	P	Cleanup of AC-Leak Syntax and Specification (AT&T)	
AVC-537	686	I	Comparison of the Cell-Loss Resilience of MPEG-2 Main Profile and  AC-leaky prediction (AT&T)	
AVC-538	-	P	Method for the correction of cell losses for low bit-rate signals transport with the AAL Type 1 (France)	
AVC-539	631	P	Semantics for skipped macroblocks in spatial scalability (BT)	
AVC-540	632	P	Semantics for prediction of motion vector in spatial scalability (BT)	
AVC-541	633	P	Syntax and semantic extensions for spatial scalability (BT)	
AVC-542	634	I/P	Spatio-temporal weighting experiments (BT)	
AVC-543	635	I/P	Accuracy requirements of upsampling (BT)	
AVC-544	641	I/P	Frequency adapted spatio-temporal weighting (BT) 	
AVC-545		I	Results on spatial scalability Core Expt. TM5 G.6.6 (Tektronix)	
AVC-546	614	D	Missing information and inconsistencies in TM2, MPEG2 Working Draft (Tektronix)	
AVC-547	645	D/P	Preliminary studies into ATM mapping of MPEG-2 Transport Layer Packets (BT)	
AVC-548	678	I/P	Experiments on the effect of losses of picture-type or f-code in picture headers (David Sarnoff)	
AVC-549	679	I/P	Experiments on the effect of loss of quantizer matrices in picture headers (David Sarnoff)	
AVC-550	637	D/P	About the transfer of MPEG transport packets in ATM (CNET)	
AVC-551	-	P	ITU-TS patent policy and MPEG-2 follow up (Siemens)	
AVC-552	N0491	R	Test Model 6 (Test Model Editing Committee)	

Abstracts

AVC-491	Test Model 5 (Test Model Editing Committee)

This is a revision reflecting the achievements obtained at the Sydney meeting.

AVC-496R	Report of the eleventh meeting in Sydney and Melbourne - March 27 - April 7, 1993 
	(Chairman)

This document records the outcome of the sole and joint sessions held in March-April 1993.

AVC-497	MPEG-2 Working Draft - Video Part - Version 4 (Working Draft Editing Committee)

This document provides agreed syntax and other texts for the video part which were edited after the Sydney meeting.

AVC-498	Work plan for broadband audiovisual systems Recommendations (S. Okubo)

This document is reproduction of a contribution to SG15 Rapporteur's meeting held in May 1993 which raised the following for discussion;

•	Time schedule for system aspects Recommendations,
•	Consideration of MPEG-2 multimedia multiplex schemes for broadband applications,
•	Protocols for desktop videoconferencing.

AVC-499	Report of ITU-TS SG 15 Rapporteur's meeting in Tokyo (N D Kenyon)

This is a report of the three day SG15 Rapporteur's meeting held in May 1993, covering H.KEY, AV.420, JPEG profile and protocols for AV Recommendations, channel aggregation, data transmission in H.320-based systems, and workplan for broadband audiovisual communications.

AVC-500	Multipoint 4 QCIF to CIF video mixing (Bellcore)

System control aspects are discussed for achieving continuous presence multipoint videoconferencing using 4 QCIF to CIF video mixing.  This document is reproduction of a contribution to SG15 Rapporteur's meeting held in May 1993.

AVC-501	Simulation studies of 4 QCIF to CIF video mixing (Bellcore)

Video coding aspects of 4 QCIF to CIF video mixing are discussed evaluating end-to-end delay, picture quality, buffer sizes and system complexity.  Experimental results are also reported, indicating that intra slice method is effective in reducing delay.  This document is reproduction of a contribution to SG15 Rapporteur's meeting held in May 1993.

AVC-502	MPEG 2 Ssytems Working Draft (Systems Committee Adhoc Group)

This was generated a the Amdsterdam meeting of the Systems Adhoc Group in June 1993.

AVC-503	Performance of the Main Profile @ Main Level - distributive and interactive services 
	(BELGACOM, UCL)

Coded results for a fixed step size are presented with bit generation statistics and processed pictures.  Original PAL sources of videoconferencing like sequence and TV programs are encoded with (M=1, N=50) and (M=3, N=50???), respectively.

AVC-504	MPEG-2 / H.26X error resilience based on data partitioning (BELGACOM, UCL)

Coded results for 2-layer data partitioning are presented where the bitstream generated is packetized at the slice level into two priorities with the low priority layer suffering 10-3 CLR.  Coded pictures for two sequences and two different sets of PBP values are demonstrated.

AVC-505  New results on spatial scalability (BELGACOM, UCL)

Experimental results are reported on comparison of simulcast vs spatial scalable coding for TV and HDTV.  SNR data and processed pictures are presented for total of 20 and 25 Mbit/s where 6 Mbit/s is assigned to the TV coding.  Spatial scalable shows 0.5 dB SNR increase compared to simulcast.

AVC-506	Concern regarding MPEG-2 Systems and ATM/AAL functionality (Australia)

Concern is expressed that ITU-TS SG15's indication of desire to use MPEG-2 Systems specifications for audiovisual communications is premature.  It is concluded that the definition of AAL Type 2 is a matter of urgency which this Experts Group should undertake at the earliest possible time, and that the objectives should include recommendations to SG13 for functionality for a generic AAL Type 2 that allows full exploitation of the network functionality while still working with MPEG-2 Systems in a simple, efficient manner.

AVC-507	H.32X terminal and MPEG-2 Systems (Aus. UVC)

This document presents an overview of H.32X terminal, AAL functionality for an audiovisual terminal, illustration of data flow in the H.32X terminal, MPEG-2 Systems functionality, and some scenarios for coping with the overlap between MPEG-2 Systems and AAL/ATM.  AAL Type 2 proposal is attached which consists of SAR (ST/SN/HEC/47 Bytes SAR-PDU payload) and CS (CMI/TS/variable size CS-PDU payload/PAD/LI/CRC).  As a conclusion, importance is stressed for establishing required AAL modes of operation before suitable mechanisms to support them are determined.

AVC-508	B-ISDN & Video Services Tutorial (S. Dunstan, Siemens) 

This document gives an overview of B-ISDN as described in the ITU-TS Recommendations, covering B-ISDN services, Protocol Reference Model, ATM layer, switching and network functions, AAL layer and signalling.  The aim is to assist in a common understanding of B-ISDN principles and terminology.

AVC-509	Flexible Object Oriented Decoding Using Slice Identification (Aus. UVC)

An idea is presented to allow separately encoding objects which consist of slices with identical identification, thus to allow separate and complete decoding of each object individually.  Each object may have fixed/variable shape and fixed/variable position from one frame to another.  For this purpose, a new syntax element slice_id (4 bits) is proposed for inclusion in the slice header.

AVC-510	FF & FR using Frequency Scalability layered coding (Aus. UVC)

Experimental results are reported for use of Frequency Scalability to achieve FF/FR functionality.  Speed up factor of 3 and 12 have been simulated for a 3-layer scheme with the lowest layer containing at maximum 2x2 DCT coefficients.

AVC-511	Report of Ad-hoc Group on ATM Cell Loss and Error Resilience   (M. Biggar, chair)

This is a report of the adhoc group activities after the Sydney meeting in March - April 1993.  Some discussions are described and error resilience description is offered for inclusion in the Working Draft.

AVC-512	Design of H.32z terminals for LANs (Aus. UVC)

Two options for the design of LAN-attached desktop multimedia terminals (H.32z terrminals) are discussed; one is to retain H.221 framing and to place one or more H.221 frames into packets for transmission across the LAN, the other is to packetize each data stream (video, audio, signalling, etc.) and to transmit them separately across the LAN using a different LAN packet.

AVC-513	H.22z protocol for LANs (Aus. UVC)

This document describes an H.22z protocol for transporting real-time audiovisual/multimedia information over packet switched local area computer networks.  The required functions are identified; packetization, multiplexing, error handling and timing recovery.  Then a corresponding packet structure is proposed.

AVC-514	Time stamp for a large picture (Japan) 

A proposal is made to the definition of Presentation Time Stamp for "large pictures", which is followed by skipped pictures, and to the handling of such PTS at the decoder.  The solution is similar in approach to the one for VBV; if the buffer does not contain complete data at the time indicated by PTS, no action is taken and checking the buffer proceeds to the next timing.

AVC-515	Considerations on AC-leaky Prediction (Japan) 

After having reviewed previously obtained study results, preference is given to that AC-leaky prediction should be outside Next Profile since existing Intra Slice and Short Slice methods provide similar effects.

AVC-516	Considerations on the next profile (Japan) 

This document lists syntactic elements which may be included in the Next Profile and provides four possible solutions, out of which Solution C (to define a single Next Profile with selected mandatory elements) is concluded preferable.  Then requirements from the audiovisual communication applications are discussed to conclude that Spatial Scalable Extension should be included as a minimum for H.261 backward compatibility and error resilience.

AVC-517	Practical examples of Hierarchical coding (Japan) 

This document lists practical examples of hierarchical coding, indicating picture and syntax of each hierarchy.  Some questions are raised toward definition of the Next Profile.

AVC-518	Syntax modification for compatibility/spatial scalability (Japan) 

A modified syntax is proposed to remove redundancy in motion vectors for spatial only prediction and in prediction_weight_code for full spatial prediction macroblocks.  Experimental results are presented to verify the effectiveness of this modification.

AVC-519	VBV operarion in 3:2 pulldown (Japan)

Based on a review of the 3:2 pulldown related coding operation, the following is proposed;
•	Period t of the VBV operation should be calculated on the parameters contained in the last picture removed from the buffer.
•	Coding should be carefully controlled for 3:2 pulldown so that VBV specification is not violated due to the change of field_count sequence between the source order and the coding order.
•	Picture skipping must not take place in the 3:2 pulldown mode.

AVC-520	Some considerations on the coding segments(Japan)

Coding-decoding delay is analyzed for concatenation of M=3 and M=1 segments.  It is pointed out that some care should be paid in coding control to maintain low buffering delay and to avoid VBV violation.

AVC-521	Correction method for cell loss and bit error in AAL Type 1 (Japan)

A cell interleaving method for AAL Type 1 is proposed which applies RS(48,44) to a block of 12 cells.  This FEC code has capability of correcting a single cell loss in the block with encoding-decoding delay of 24 ms at 384 kbit/s.  This document also discusses separation between SAR and CS, protection against successive cell losses, hardware complexity and extension to other AAL.  Items requiring SG13 advice are pointed out; partitioning SAR and CS, use of CSI bits.

AVC-522	VBR coding and octet interleave (Japan) 

Experimental results are reported for the two methods to give upperbound for the octet interleaving delay; to keep a minimum bitrate, and to set a time-out for flushing the interleaver matrix.  It is shown that both methods are effective in reducing the delay and increase of the step size is small, particularly if there is more strict UPC.

AVC-523	Low delay IPB mode transmisssion using VBR (Japan) 

Experimental results are reported to achieve low delay by the utilizaion of periodical nature of the VBR coded bit generation in IPB structures.  Two mehtods are studied; use of special relationship bwteen the GOP size and UPC window size, and declaration of a higher average bitrate.

AVC-524	Relation between MPEG-2 transport mux and ATM/ALL and possible candidates for AAL 	(Japan)

Based on review of the MPEG-2 Systems and the I.363 AAL, relationship between them is discussed for designing audiovisual communication terminals.  It is concluded that use of PES packets may be preferable for video service integration, but use of TS packets may be redundant.  A notion of H.32X transport packet is offered for discussion which segments the PES packet and have such features as variable length to support different QoS, software implementation.  Appropriate AALs to transfer the H.32X transport packets are also discussed; Type 5 and Type 4 SAR modified.

AVC-525	Telecommunication requirements for the Next profile (NL,I,UK,N,FRG)

The following requirements from telecommunication applications are listed as mandatory; H.320 interworking (including video, audio, multiplexing, call control, etc.), H.261 compatibility, MPEG-1 compatibility (including video, audio, systems), low end-to-end delay (less than 150ms), cell loss resiliency (up to 10-2 CLR), bitrate range from 64 kbit/s to several tens of Mbit/s.

AVC-526	Telecommunication levels for the Next profile (NL,I,UK,N,FRG)

Two specific levels in the Next Profile is discussed for telecommunication applications; Main level, (wide screen) SCIF level.  Selection of syntactic elements for the Next Profile is also discussed by marking the TM5 syntax.

AVC-527	Software decoding of video streams (PTT Research)

Information is provided on the design and implementation of a software decoder for MPEG-1 video streams (paper by K. Patel et al).  It is shown that memory bandwidth is the primary limitation in performance of the decoder, not the computational complexity of IDCT.

AVC-528	Inter working between wide screen SCIF and SCIF video conferencing systems
	(PTT Research)

The following three interworking situations are depicted which are covered by the MPEG-2 syntax;
•	interworking between the H.32X B-ISDN normal screen terminal operating at SCIF and the H.320 N-ISDN terminal operating at CIF,
•	interworking between the 16:9 wide screen SCIF terminal and the 4:3 normal screen SCIF terminal by means of side panel,
•	interworking among the three stated above.

AVC-529	On the B-frame design complexity of spatio-temporal weighting (NL)

This document examines hardware complexity for supporting B frames and spatio-temporal weighting, obtaining the following conclusion;
•	Spatio-temporal weighting gives a gain in SNR performance which may further increase by the future techniques.
•	It requires higher memory bandwidth, but if B frames are incorporated, the resource can also be used for spatio-temporal weighting in I and P pictures.
•	For M=1 coding, support of spatio-temporal weighting requires additional memory  bandwidth.

AVC-530	European stance on leaky prediction (F,FRG,B,N,I,NL,UK)

The inclusion of the AC-leaky prediction is not supported, for error concealment purpose, in the NEXT or the SIMPLE profile on the grounds that it does not outperform other existing solutions.

AVC-531	Simulation results on AC-leaky prediction (F)

This paper follows the main guidelines of Core Experiment F4 on AC-leaky prediction.  The following aspects are tested : coding performances without loss and cell loss concealment capability.

AVC-532	Cell loss resilience: simulation results on concealment techniques (F)

This paper provides some results on the concealment techniques proposed in TM5 : Substitution from previous frame with and without motion compensation , Intra MV.  Simulations are done in M=1 context.

AVC-533	Experiment on spatial/temporal H.261/H.26x compatibility (F)

This paper presents the results of a (core) experiment about H.261/H.26x compatibility by using the two layered prediction scheme. We used the prediction_weight_code table proposed in TM5 , which includes a half compatible/half temporal prediction.  Simulation results and our point of view concerning the need of this latter prediction mode are given.

AVC-534	Comparison of CTV/HDTV compatible coding schemes (ETRI)

Coding performance (SNR) is reported for the following two CTV/HDTV compatible coding schemes at 12+13.5 Mbit/s; pyramidal DCT, and spatio-temporal predictive coding.  Both of the base layer and upper layer use TM5.  Two up/down conversion filters of CMTT and MPEG are also compared.  It is concluded that the spatio-temporal prediction method gives a little superior performance and that the TM5 filters give better performance in the spatio-temporal scheme.

AVC-535	Invitation to the 14th ATM Video Coding Meeting (ETRI)

This document provides information on the meeting in Daejon

AVC-536	Cleanup of AC-Leak Syntax and Specification (AT&T)

AC-leak syntax is proposed to be a separate extension with its own unique identifier.  Semantics for the AC-leak are also clarified.

AVC-537	Comparison of the Cell-Loss Resilience of MPEG-2 Main Profile and  AC-leaky prediction 
	(AT&T)

Experimental results are reported for the AC-leak method comparing with the Main Profile (N=15); quality when there is no error, cell loss resilience, and channel hopping speed.  It is concluded that;
•	quality for M=1 with D=6 and N=15 is nearly identical,
•	the AC-leak gives visually less objectionable pictures against cell losses, particularly with D=6,
•	in the worst case a very clear image is available after 12 frames with D=6, but the picture is very recognizable after 6 frames.

AVC-538	Method for the correction of cell losses for low bit-rate signals transport with the AAL Type 	1 (France)

This documents intends to respond to the liaison from TG CMTT/3 which is requiring a cell loss correction method adapted to high quality sound transmission with low delay at low bitrates.  The method uses diagonal octet interleaving for 16 cells and FEC (RS codes).  As a conclusion, a common cell loss correction method is proposed for all real-time low bit-rate services using AAL type 1.

AVC-539	Semantics for skipped macroblocks in spatial scalability (BT)

This document proposes clarification and addition to WD for skipped macroblocks taking spatial scalability into account.

AVC-540	Semantics for prediction of motion vector in spatial scalability (BT)

This document proposes clarification and addition to WD for prediction of motion vector to include spatial scalability.  VLCs for macroblock_type are also proposed.

AVC-541	Syntax and semantic extensions for spatial scalability (BT)

This document proposes a picture layer syntax for spatial scalability as well as a macroblock layer syntax for snr scalability.

AVC-542	Spatio-temporal weighting experiments (BT)

Experimental results are reported for coding efficiency and picture quality of the three methods of spatio-temporal prediction; simple switching, simple switching plus averaging, optimum continuous weights.  It is concluded that the third method which requires downloadable weights is not worth the cost, and that the second average mode method gives a little gain, while increasing the complexity a little, thus is proposed to be in the standard.

AVC-543	Accuracy requirements of upsampling (BT)

Experimental results are reported for comparison between 4 different upsampling filters in the decoder in the spatial scalable scheme where an encoder upsampling filter is used   It is concluded that the upsampling process need not be performed exactly the same in the encoder and decoder to get the same subjective picture quality at the encoder and decoder and that the simplest interpolation is sufficient.  The pel repetition, however, gives poor quality.

AVC-544	Frequency adapted spatio-temporal weighting (BT) 

Experimental results are reported for frequency adapted spatio-temporal prediction where the spatio-temporal prediction signal is derived by averaging the two horizontally low passed components (spatial one and temporal one) and adding the temporal high pass component.  It is concluded that this technique gives a small but noticeable gain, thus a core experiment is proposed for its optimization.

AVC-545	Results on spatial scalability Core Expt. TM5 G.6.6 (Tektronix)

Experimental results are reported for comparison of coding efficiency (SNR) between simulcast, spatial scalability with weighted prediction and spatial scalability with binary selection.  It is concluded that there is an SNR gain from using either of spatial scalability and that spatial scalability with binary selection performs better than spatial scalability with weighted prediction.  It is also stated that spatio-temporal weighting adds hardware complexity.

AVC-546	Missing information and inconsistencies in TM5, MPEG2 Working Draft (Tektronix)

Some items needing correction or new definition are pointed out for the specifications of WD (MP@ML) and TM5 (spatial scalability).

AVC-547	Preliminary studies into ATM mapping of MPEG-2 Transport Layer Packets (BT)
AVC-550	About the transfer of MPEG transport packets in ATM (CNET)

Methods for transmitting MPEG-2 TS packets over ATM networks are discussed referring to the Bellcore contribution to the Atlanta Systems group meeting.  Assuming that transmission efficiency and cell loss resilience are of prime importance, the following scenario is proposed as the best compromise; use of AAL Type 1, no padding octets by use if "alignment" mapping and packet length of nx47 octets.

AVC-548	Experiments on the effect of losses of picture-type or f-code in picture headers 
	(David Sarnoff)

Experimental results are reported on the impacts of picture header information loss causing serious damage in decoded pictures.  It is proposed to allow redundant transmission of very sensitive data within the picture headers to improve the noise channel performance.

AVC-549	Experiments on the effect of loss of quantizer matrices in picture headers (David Sarnoff)

Experimental results are reported on the impacts of quantizer matrix information loss.  It is concluded that quantizer matrix changes slightly degrade the quality of decoded pictures, thus redundant transmission of this information is not required.

AVC-551	ITU-TS patent policy and MPEG-2 follow up (Siemens)

The ITU-TS policy is reminded and it is proposed that the AVC Rapporteur Group starts collecting patent information and that the Group declares its desire to follow the waiving approach.

AVC-552	Test Model 6 (Test Model Editing Committee)

This document describes experiments on optimization of upconversion filter for spatial scalability, optimization of macroblock type tables and verification of temporal scalability.

Temporary Documents

TD-1	Chairman	Agenda for the sole sessions in Boston	
TD-2	Chairman	Available documents for the Boston/New York meeting	
TD-3	Chairman	List of tape demonstrations	
TD-4	G. Bjoentegaard	Proposed text for WD Annex C	
TD-5	Chairman	List of open issues - April 1993	
TD-6	Chairman	Fields in Protocol Data Unit and their functions	
TD-7	Chairman	Independent clocks and their recovery methods	
TD-8	S. Dunstan	Results of meeting to discuss ATM/AAL and MPEG-2 Systems	
TD-9	Chairman	Summary of the discussion on AC-leaky prediction	
TD-10	S. Okubo, K. Asai	Cell loss correction method for AAL Type 1 to support H.320 terminals in B-ISDN	
TD-11	Chairman	Agreements and actions (substitute of the meeting report)	
TD-12	A. Tabatabai	Report of the small group work to sort out the discrepancies in proposed solutions for the spatial scalable syntax	

END