The Chair opened the meeting at 11:32, participating via GoToMeeting from the UK.
Present were Paul Treleaven, Richard Cabot, Michael Poimboeuf, Jim Meyer, Andy Rosen *, Anthony Kuzub *, John Grant* (* denotes by electronic link)
The formal notice on patent policy was read.
The agenda, and the report of the previous meeting, held in Dublin, Ireland, 2019-03-22, were approved 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.
All projects in the main part of the agenda have been reaffirmed this year, and there was no discussion of any of them.
AES-R8-R: Review of AES-R8-2015: AES standards project report - Synchronisation of digital audio over wide areas
Reports, unlike standards, do not need to be reviewed every 5 years; however, the meeting felt that there are some issues with timing and clock recovery that have arisen since 2015 and should be addressed. R Cabot had seen significant jitter/wander on Dante networks; there can be a jump in the frequency of the A-to-D clock on PTP updates (every quarter of a second). J Meyer had also found that 100Mbps Dante devices would have their clock "wander" when significant amounts of other traffic were on the network. J Grant observed that IP networks were never intended to carry timing information. A Kuzub observed that SC-02-12 is also studying timing issues on networks, and R Cabot suggested that it could also be relevant to SC-02-01.
The meeting discussed a proposal from A Kuzub for a standard to add a suffix to the notation defined in Table 1 of AES72 to define how signals are assigned to the four pairs (two channels per pair when carrying AES3, one for analogue), for various use cases. A Project Initiation Form needs to be submitted through the usual channels.
No new business was raised.
The meeting closed at 12:15.
The next meeting will be held in Vienna, Austria 2020-05, in conjunction with the AES 148th convention.