[Tinyos-devel] TEP105: LowPowerListening Duty Cycles

[Razvan Musaloiu-E.]

Hi!

I completely agree. In order to avoid this complexity LPP [1] is using a 
very simple interface called LowPowerProbing which only contains 
setLocalSleepInterval and getLocalSleepInterval.

[1] http://tinyos.cvs.sourceforge.net/tinyos/tinyos-2.x-contrib/jhu/lpp/

--
Razvan ME

On Wed, 14 May 2008, David Moss wrote:

> Is anyone using the setLocalDutyCycle() and setRxDutyCycle() functions in
> the LowPowerListening interface?
>
>
>
> I see lots of problems with all duty cycle related functions in the
> LowPowerListening interface:
>
>
>
> 1.	Duty cycle functions are very inaccurate and difficult to maintain
> because they require manual measurements to be performed on a node.
> 2.	The correct value may even vary from platform to platform, depending
> on the implementation. In some cases, like hardware-driven Wake-on Radio, it
> is difficult to specify a duty cycle with any degree of accuracy.
> 3.	Any changes to the radio stack, including unrelated areas like
> Acknowledgments, will affect the duty cycle and require the developer to
> make measurements again.
> 4.	The limitations on the duty cycle percentage only let you get down
> to 0.01%.  With the ever-increasing efficiency of receive checks, 0.01% is
> not be enough.  In some implementations, I'm able to achieve numbers like
> 0.0001% duty cycle or lower, which makes all duty cycle functions obsolete.
>
>
>
> Given these on-going problems with setLocalDutyCycle() and setRxDutyCycle(),
> it is my opinion that the best thing we can do is @deprecate these functions
> for now, leave them available for the next release as we ease out of them,
> remove them from TEP105, and avoid using them at all costs.
>
>
>
> The setRxSleepInterval() and setLocalSleepInterval() functions are much more
> reliable, predictable, cross-platform compatible, and always correct.
>
>
>
> Thoughts?
>
>
>
> -David
>
>
>
>