[Tinyos Core WG] [Tinyos-devel] packet timestamping and packet-level timesynchronization

[Philip Levis]

On May 14, 2008, at 1:16 PM, Janos Sallai wrote:

>>> it would be important for the timestamps and
>>> for the timesync protocol to be able to support parameterizable  
>>> width
>>> and precision. (PacketTimeStamp interface)
>
> It appears that we do not have a consensus on this.
>
> Reasons for parameterizing with precision _and width_:
> - It's more flexible and probably future proof.
> - Would allow for 64-bit time values. Is this _really_ required for  
> the
> imote2?
> - Would allow for 16-bit time values, to save some space in the  
> message
> payload.
>
> Reasons against it:
> - Sources would get more verbose.
> - LocalTime is not parameterized by width, either. To access non-32- 
> bit
> local time, a custom interface would be required anyway.

The tradeoff is between flexibility of the interface in all of its  
uses and the simplicity of its use in common cases.

LocalTime took the position that forcing all users/providers to  
parameterize width because some components might want other widths was  
not worth it, in part because Timer has a 32_t. But stuff like Counter  
is parameterized with both precision and width because of the  
diversity of its use.

Phil