[Sugar-devel] [Design] Ad-hoc networks - New Icons

[Gary C Martin]

Hi Daniel,

On 11 Aug 2009, at 17:19, Daniel Drake wrote:

> 2009/8/11 Gary C Martin <gary at garycmartin.com>:
>> Hmmmm. Are you sure this is an accurate statement? I was under the
>> impression that mesh forwarding support had been removed/disabled  
>> from OLPCs
>> implementation a long time ago, since soon after the Mongolia  
>> deployment.
>> Mesh was killing the wireless spectrum with all the attempted packet
>> retransmissions. It is really only 'mesh' in name, all devices have  
>> to be in
>> range of each other to collaborate.
>
> Yes, forwarding still happens.

Many thanks for that correction! I wish I'd seen some test data for  
these scenarios, with access to 3 XOs myself I'm very curious to go  
perform some tests now that you've confirmed it's not disabled  
(machine A, B C all on mesh, but with A and C out of direct wireless  
range, using B as the hop).

> And the mesh does scale quite well for sparse setups (its original
> design). It also works quite well in dense setups (e.g. classrooms) in
> that it allows reliable communication between about 15 nodes -- that's
> about 13 more than we were able to do reliably with the other
> infrastructure-free networking option (IBSS/ad hoc).

Ouch, well glad to hear testing was done on ad-hoc, that was before my  
time following OLPC.

> of course,
> classrooms of that size (that are additionally RF-space isolated from
> other XOs) are not very common so we need other solutions there.

So. From a design stand point, the tested, technical issues direct us  
to focus on making the creation of small ad-hoc groups (of just 2?)  
the sweet UI spot.

If you exclude the A can see B and C, but B cant see C case, does ad- 
hoc really fail so badly for ~5 kids in a room?

Regards,
--Gary