On Mar 31, 2007, at 5:26 AM, Jens M Andreasen wrote:
What I wonder is; wouldn't it be possible to bypass this USB radio transmitter/recaiver dongle-thingie and fast forward to the wireless capabilities already built in to most of modern portable devices sold today? Hey, even the OLPC aimed at third world children have this capability ...
If you access to two OS X machines for a few minutes, run the Network MIDI Driver over Airport (Network MIDI Driver described here: http://www.soundonsound.com/sos/jul05/articles/tiger.htm#3 You'll see it works OK, even with the 1-2% packet loss that the IP layer sees on a typical WiFi network. Apple's implementation uses IETF RFC 4695 (a.k.a. RTP MIDI) as the transport layer, which includes a resiliency system (the recovery journal) for handling an arbitrary number of lost packets with only transient artifacts. More on RTP MIDI here: http://www.cs.berkeley.edu/~lazzaro/rtpmidi/index.html Note that there are actually third-party products now compatible with Apple's protocol, although these products are for wired networks. And, last time I checked didn't implement the recovery journal part of the RTP MIDI (and so can't be trusted over switches that lose packets -- although my info on the product might be out of date): http://www.kiss-box.com/products.pdf
It kind of puzzles me that this is not happening already ...
I haven't looked into the issue in detail, but for my own use wireless only makes sense if I don't have to be constantly worrying about the battery life of the device. At the moment, what I see in the state of the art in portable WiFi chips -- the chip in the Sony PSP and the chip in the Microsoft Zune -- is not too encouraging in this regard. But hopefully in a few generations of chip designs this will get better. This review: http://emusician.com/midi/emusic_maudio_midair/ make the point well of how limiting the battery life can be for a MIDI wireless controller right now. --- John Lazzaro http://www.cs.berkeley.edu/~lazzaro lazzaro [at] cs [dot] berkeley [dot] edu ---
