limits on ad-hoc connections
sverma at sfsu.edu
Wed Feb 8 14:56:52 EST 2012
On Wed, Feb 8, 2012 at 4:23 AM, Martin Langhoff
<martin.langhoff at gmail.com> wrote:
> On Wed, Feb 8, 2012 at 6:16 AM, Sridhar Dhanapalan
> <sridhar at laptop.org.au> wrote:
>> Ad-hoc connections only scale to a limited number of participants
>> before problems begin to occur.
> The technically correct answer is "it depends". And it is true, it
> depends on a ton of factors.
> As a rule of thumb, I've seen it work for groups of 5~6 units,
> physically close and without interference sources or reflective
> materials. I would not aim higher than that -- 5~6 units in a channel.
> You have 3 channels, so 3 groups of 5~6 units.
10 per channel on mesh. Given that 802.11s draft vs ad-hoc is really a
layer 2 issue, the numbers should be in that neighborhood?
> To clarify: keep any other laptops and cordless phones in the vicinity
> _off_, to allow these 18 users to work. In practice, it won't work in
> a school, but if you invite a few schoolmates home after school, or in
> the park, you're fine.
> No warranties expressed or implied. There's a long laundry list of
> things that can interfere, and make things not fine.
> For example, professional TV cameras from that friendly news crew
> transmit in the 2.4GHz band. That battery pack feeds a powerful
> antenna to get the signal back to the van that has the uplink, and it
> paves over consumer-grade wifi.
> So don't count in wifi (of any kind!) to work for a demo or
> show-and-tell when you get TV coverage at a school :-)
>> Can we impose a hard limit on the number of clients to prevent too
>> many XOs connecting to a single ad-hoc session?
> As James says... unfortunately no.
> martin.langhoff at gmail.com
> martin at laptop.org -- Software Architect - OLPC
> - ask interesting questions
> - don't get distracted with shiny stuff - working code first
> - http://wiki.laptop.org/go/User:Martinlanghoff
> Devel mailing list
> Devel at lists.laptop.org
More information about the Devel