Report of the meeting of the SC-02-12 Working Group on Audio Applications of Networks of the SC-02 Subcommittee on Digital Audio held in conjunction with the AES 141st Convention in Los Angeles, CA., US., 2016-10-01.
The meeting was convened by chair Richard Foss.
The agenda and the report of the previous meeting, 2015-10-30, were accepted as written.
Projects assigned to this group but not mentioned here had no action requested or required - see www.aes.org/standards/meetings/project-status.cfm for details.
Open Projects:
AES64-R: Review of AES64-2012, AES standard for audio applications of networks - Command, control, and connection management for integrated media
This standard is due for review in 2017, and any revision should be performed before the review date. The capabilities that are particular to the protocol should also be highlighted in the associated informative document, AES-X170B.
There was concern expressed by one of the working group members about the presence of two AES control protocols. In the meeting it was pointed out that, although there is overlap in terms of the functional goals of the two protocols, there are also distinct capability differences that would fulfill different use cases.
AES67-R High-performance streaming audio-over-IP interoperability
There was discussion relating to two AES67-related reports.
AES-R15-2015 Standards project report - AES67 Interoperability PlugFest - Washington 2015
AES-R16-2016 AES Standards Report - PTP parameters for AES67 and SMPTE ST 2059-2 interoperability.
See also project AES-X226, below.
AES70-1 AES standard for audio applications of networks
An SC-02-12-L meeting was held prior to the working group meeting and task-group leader Jeff Berryman provided the following report:
Discussion centered around upcoming AES70 revisions. The OCA Alliance is almost ready to submit a set of recommendations for AES70 revisions based on OCA 1.4, and hope to offer a draft proposal within about four months.
Liaison with the SC-04-04 (microphones) project - This is a new topic arising from discussions in this convention. SC-04-04 is almost finished with defining an OCA profile for remote control of wired microphones, but needs to add specifications for wireless microphones. For this purpose, the AES70 revision will need to include wireless classes such as transmitters, receivers, and spectrum analyzers. Action: SC-02-12-L and SC-04-04 will define mutual rapporteurs to facilitate the required designs.
Development Projects:
AES-X226 AES67 protocol implementation.
An SC-02-12-M task-group meeting had been held just prior to this working group meeting. Task-group leader Kevin Gross reported:
Plugfest scheduling: there are many interoperability test (interop) events happening. Do we want to combine our plugfest testing with another body? Are there people interested in an audio-only plugfest? It would be ideal if we had new things to test and new implementations to test with. Bruce Olson presented a calendar produced by the Joint Taskforce - Networked Media (JT-NM), noting that it is subject to change and is provided as a planning tool only.
Timing: 1Q2017 the SMPTE/AES group may hold an event at a location to be determined to further advance the work, but no specific plans for such an event are scheduled at this time.
Transport: January 2017, an engineering interop will be held at The Woodlands, TX, focused only on advancing interoperability around the proposed SMPTE ST-2110 standard. This event will focus on systems testing, and will include video, audio, timing and ancillary data. Successful participation at this event will be required for vendors who wish to participate in the public demonstration to be held at VidTrans17. While not mandatory, vendors with substantially new implementations of ST-2110 should attend this interop session if they want to participate in the NAB public interop.
D&R: January 2017 (tentatively in San Jose, CA) to advance work on connection management and network controller API.
VidTrans17 Public Demonstration (February 28, 2017) ST2110 only. Simple, static A-to-B style demonstration. Participating companies must attend the January Woodlands event and must be exhibitors at VidTrans17.
NAB Demo Integration: (Late March, 2017) Likely focused on ST-2110 and IS04 D&R. Intent is that the NAB demo is fully staged at this event. Demo will ship directly to the NAB floor. Successful participation at this event is mandatory for all vendors who wish to participate in the NAB demo.
NAB 2017 Demo: April 24 to 27 in Las Vegas.
AES67 plugfest: Gross observed that there are new AES67 implementations that have not participated in a plugfest, and manufacturers who are not participating in SC-02-12-M. Public demonstrations are not engineering oriented.
He also observed that a plugfest stands on 3 legs: a host, a leader, and participants. A proposal exists for a plugfest to be hosted by the Jamie Laundon of the BBC in the UK. Proposed dates: 13 - 16 February, after the ISE exhibition. A leader has not yet been identified. We also need to assess potential participation for this proposal.
The AES67 Protocol Implementation Conformance Statement (PICS) comment resolution is making progress. Fundamental topics include: a matrix of formats, SDP for declaration and negotiation, and a requirement for a stream with fewer than 8 channels.
It was proposed to revise AES67 clause 7.3 to indicate "sender shall be able to offer..." (This revision suggestion has been added to proposed AES67 projects and revisions)
The fundamental topics were covered during the meeting and Gints Linis felt he had the input he needed to move forward to the next revision. Gross will post a doodle poll to schedule 2 hour teleconferences every other week to finish the comment resolution.
AES-X238 Network Directory Architecture
There was a meeting of the SC-02-12-N task group. The issues that this project needs to address were outlined, and substantive work will be taking place in bi-weekly teleconferences of this task group in the next months.
Berryman has provided a powerpoint presentation which contains his notes of the meeting. This has been uploaded to the working group document site as SC-02-12-N-minutes-161001.pptx.
Liaisons:
AES-X075 Liaison with IEC TC100 for IEC 61883
Junichi Yoshio provided a PowerPoint presentation that details IEC TC100 activities that are relevant to the working group. This has been uploaded to the working group document site as IEC_Liaison_Report.pptx.
AES-X170B AES standards report - supplementary information on AES64
The report is unchanged since 2011. This report will be reviewed when the associated standard, AES64, is revised.
Liaison with Ethernet AVB related working groups
Matt Mora was on hand to provide us with an update. He noted:
a) The change of naming from AVB to TSN (Time Sensitive Networking), indicating a wider application domain.
b) Update to the reservation schemes within 802.1 AS.
c) A revision of the IEEE 1722 document, also noting that IEC61883 is no longer used.
d) Small changes to IEEE 1722.1.
Olsen indicated that he would initiate a liaison with AVNU and would contact Mora in this regard.
Liaison with MPEG
John Grant provided us with a written report that was read out:
"There is an addition to MMT on enhancements for mobile environments (ISO/IEC 23008-1/PDAM 2) out for CD (Committee Draft, the first stage) ballot, and a group of extensions to DASH (ISO/IEC 23009-1:2014/DAmd 4) out for DIS (Draft International Standard, a later stage) ballot.
ETSI ISG NGP https://portal.etsi.org/tb.aspx?tbid=844&SubTB=844#5068-home will publish its Scenarios document for Next Generation Protocols, detailing requirements for a number of use cases, soon. However, I don't think there will be anything in it relevant to audio. It's looking increasingly likely that the group will end up recommending some tweaks to IP to aid mobility (keeping TCP sessions alive on handover to a different cell) but not anything that would benefit live media.
ISO/IEC JTC1/SC6/WG7 has begun standardisation of what they still call "Future Network". Two families of standards are planned, ISO 21558 Future Network Architecture and ISO 21559 Future Network Protocols and Mechanisms, incorporating the kind of technology that live audio needs. "
Liaison with IEC 62379-1
Peter Stevens provided us with a written report, which he referred to:
IEC 62379-1, the core document of this series, laying out the framework, has reached it's maintenance date within TC100 and is currently being revised. Apart from errors in the specification being corrected, it is expected to include additional time related improvements, such as 3 time-server entries for better time correction, improvements in the real-time clocks, support for PTP and TAI, and revisions related to other documents in the series which have been developed since the original publication in 2007.
New Business:
New chair of SC-02-12
As I mentioned at the meeting in New York, my current research and development focus has shifted to immersive sound, and this has meant that I have not been tracking audio network transport and control issues, as I feel the chair of this group should. Very fortunately for this group, Morten Lave has made himself available to take over the position. As many of you know Morten has a wealth of audio networking, and indeed audio engineering experience. His appointment to chair met with the approval of those present at the meeting. Personally, I am delighted that someone of his stature will be leading the group. Chairing the working group meetings has been a yearly highlight for many years, and I plan to remain in contact with the group for many years to come.
The next meeting will be scheduled in conjunction with the AES 142nd Convention in Berlin, Germany, 2017-05.
