[Tinyos-devel] CTP and LPL on tmote

[Philip Levis]

On Nov 26, 2008, at 8:00 AM, Andreas Köpke wrote:

> Philip Levis wrote:
>> On Nov 25, 2008, at 12:41 PM, Andreas Köpke wrote:
>>> Hi, has anyone ever got CTP to run with LPL on  a tmote sky at a
>>> duty cycle
>>> smaller than 10%? In our tests with 5% the ETX values are way above
>>> any
>>> reasonable value.
>>
>> net2 is actively working on this now.
>>
>> Phil
>
> Are there any theories why there is a problem? Anything we could  
> test/do to
> help in the process?

Very good question. Unfortunately, it's the day before Thanksgiving,  
so responsiveness from Americans is kinda low until Monday. Let's  
talk about it then?

To give a bit of background, in developing CTP we sketched our  
performance goal timeline like this:

1) Accurate ETX estimation and minimizing data path (data packets/ 
delivery) cost
2) Minimizing control traffic
3) Integrating and testing with LPL

Right now we are on 3. Part of the trick with 3 is that it depends on  
the LPL implementation. It works very well with the CC1100 and CC2500  
implementations (the ones David Moss supports most actively). We're  
just now collecting experimental traces with the CC2420 one.

Phil