[OLPC Networking] [Server-devel] RSSI value questions

[John Watlington]

On Apr 2, 2008, at 5:05 PM, John Watlington wrote:

>
> On Apr 2, 2008, at 4:00 PM, Martin Langhoff wrote:
>
>> On Wed, Apr 2, 2008 at 3:38 PM,  <david at lang.hm> wrote:
>>>  the problem with trying to use sound is that it requres a clear  
>>> path from
>>> the servers to the laptops, something I would not expect to see  
>>> very much.
>>> it's also very sensitive to the direction the laptops are pointing.
>>
>> Absolutely, and the XS doesn't have mics, even less directional  
>> mics ;-)
>
> It's in that hole on the left hand side of the screen...

It has been pointed out that I've gotten to old to tell the difference
between XO and XS.    I have no defence...

We could make the XS beep, and triangulate its location from the laptop
locations...

>> The 802.11 signal will also have dirty paths in some directions.
>> Strategic antenna location and signal timing is the only way I can  
>> see
>> this working. It would be fantastic to have a simple thing to demo
>> physics and maths based on such triangulation.
>
> At 2.4 GHz, the interference between multiple paths makes
> signal level measurement pretty useless for determining position.
> If you do this to a number of spatially distributed access points,
> you can improve the estimate...   This is how the Bluetooth Location
> service works...
>
> wad