[Tinyos-devel] [Tinyos Core WG] TEP105: LowPowerListening Duty Cycles

[Philip Levis]

On May 14, 2008, at 11:35 AM, Janos Sallai wrote:
>
>
> I think TEP 105 should redefine the semantics of cancel, without the  
> clause that requires that the packet is not transmitted yet (or with  
> an error code different than ECANCEL in sendDone?).

I disagree. If LPL is using a BMAC style channel modulation, the the  
transmitter can return SUCCESS and signal sendDone with ECANCEL. If it  
is using XMAC-style cyclic sending, then it must return FAIL on  
cancel(), but can signal an early sendDone() with SUCCESS. The packet  
did go out over the air; the chances the receiver got it are much  
lower than if the complete send cycle occurred, but they are non-zero.

>
> 2.  Send
>
> The LPL TEP says that “If a message is already in the process of  
> being sent, multiple calls to Send should return FAIL.”. This is in  
> conflict with TEP 116, which requires that send should return EBUSY.  
> The LPL TEP should require returning EBUSY as well.

I agree.

Phil