On Fri, Apr 10, 2009 at 6:47 PM, Geza Kovacs <gkov...@mit.edu> wrote: > Assuming I'm using Farsight2 to broadcast MJPEG video over multicast UDP,
As I've posted earlier, for multicast frames you'll see the AP switching to the slowest transmission speed to increase the chances that all the nodes will get the frame reliably, which hogs airtime. And airtime is what really matters in wireless networking. So, if one session of your proposed application is the *only* thing running on the whole network, you can do some rough math. You'll need to - Send the stream to the AP. If the 'broadcasting' node is close to the AP, and sees no interference, it may be able to transmit relatively fast (let's assume 36Mbps). - Broadcast the framesfrom the AP at 1Mbps. What's the bits-per-second of your stream? What % of the airtime do you thing it will consume? This of course assumes 802.11abg. With 802.11s, sending a stream over broadcast will mess up the network completely because of the funny rebroadcasting rules in the 's' standard. All OLPC deployments are a very busy wifi environment. If you build tools that assume that they are the only thing in the air, or that it can take a significant portion of the RF airtime... would be just like assuming that your program is the only thing in the hard disk. cheers, m -- martin.langh...@gmail.com mar...@laptop.org -- School Server Architect - ask interesting questions - don't get distracted with shiny stuff - working code first - http://wiki.laptop.org/go/User:Martinlanghoff _______________________________________________ Sugar-devel mailing list Sugar-devel@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/sugar-devel
