23 Dec
2009
23 Dec
'09
6:54 p.m.
On 12/23/2009 08:08 PM, Arnold Krille wrote:
On Wednesday 23 December 2009 09:12:24 Patrick Shirkey
wrote:
So the issue is with other streams being picked up by the receiver which
affects latency by increasing collisions?
Would this still be a problem on a secured connection? Surely the
receiver would ignore all data that is not being transmitted over the
secured access point?
Does anyone have an idea of how to work out the actual latency for a
wifi packet at 300Mb/s?
If we are talking about a studio setup with devices no further than 2
meters distance from each other that should aloow sub 20ms send/receive.
The bottle neck appears to be the chip and the code that manages the
transmit/receive process.
Patrick Shirkey
Boost Hardware Ltd
On 12/23/2009 09:40 AM, Jörn Nettingsmeier
wrote:
There is no way to make it work with guaranteed low latency. You need
somewhat
low latencies to play the keyboard to other music. And you need it guaranteed
unless you always record xruns and gaps as part of your musical experience...
And even then its wireless and using a frequency-range used by almost all
other people around you. Just count the wireless networks in your flat provided
you live in a flat with other people living upstairs/downstairs/next to you.
And then try to get a fast, non-interrupted stream (latency about 20ms or
shorter for real playing).
Patrick Shirkey wrote:
So there's absolutely no way that a keyboard, pc, mixer, speaker set
transferring data over 802.11n could be made to work?
For example in a home studio setting...
I had a thought that maybe the network sound card
should not be using
ethernet but instead wireless 802.11n.
The ralink rt2870 chipset is well supported at full 300Mb/s on Linux and
has open source drivers.
I think this would open up a lot of opportunities with a wireless sound
card.
I'm not sure how many are on the market right now but I haven't heard of
any yet so there is a big opportunity there to fill a gap.
low latency audio over wireless is fundamentally impossible.
it's a shared medium, pretty much like thicknet or any other hub or bus
network. if two endpoints ever send at the same time (and they will),
the packets will clash and trigger resends after a non-deterministic
delay (so as to avoid endless re-clashing if two endpoints happen to be
"in sync").
the only thing that would work over wireless is heavily-buffered media
center stuff for consumers, because nobody cares if there's half a
second delay between your pressing play and the start of the movie.