[Tinyos-devel] [Tinyos Core WG] TEP105: LowPowerListeningDutyCycles

[Philip Levis]

On May 19, 2008, at 11:31 AM, Andreas Koepke wrote:

> To settle this: we stick to the PacketAcknowledgements interface to  
> tunnel the Reliable stuff through the AM layer.
>
> The original problem was the cancel optimization. I strongly dislike  
> side effects of a cancel that returns FAIL. Side effects are evil.
>
> I think that cancel is an optimization -- it is not necessary to  
> have the semantics "this packet will not arrive for sure". An "I  
> don't care anymore that this packet arrives" seems much more natural  
> to me.

I don't understand; the LPL cancel behavior I proposed don't have this  
property. SUCCESS on cancel means "this packet will not arrive for  
sure." FAIL means "this packet might arrive." That's no different than  
any other packet, of course. However, you could cancel the LPL  
transmissions. Since sendDone *never* means "this packet arrived for  
sure," that works fine.

Phil