Depends on the driver.
For the serial stack.  It does indeed indicate that the packet has been
sent.

For the radio stack, I'm not sure.  I suspect that the sendDone is generated
when all of the packet has been transferred to the radio hardware.  Looking
at the details of the radio driver will shed some light on this.  Note that
there are different drivers for different radio h/w and that can also give
different behaviour.

Knowing that the packet has hit the air doesn't really buy you all that
much.  Knowing that the intended receiver has gotten the packet does.  Hence
the ability to have packets be ACK'd.

eric

On Thu, Aug 27, 2009 at 2:29 AM, Ibrahim Orhan <[email protected]>wrote:

> Hi all,
> When sending a packet in TinyOS-2.1, you receive an
> event(send.sendDone) telling that the packet was successfully sent.
> It*s possible to read this in the error_t parameter. Does this mean
> that the packet has been really sent over the air? Can it be so that the
> radio(or a lower layer) receives the packet and due to CSMA/CA, tries a
> few times (backoffs) and then discards the packet and we still get that
> the packet was successfully sent?
> Thanks in advance
>
> Regards
> Ibrahim
>
> _______________________________________________
> Tinyos-help mailing list
> [email protected]
> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
>



-- 
Eric B. Decker
Senior (over 50 :-) Researcher
Autonomous Systems Lab
Jack Baskin School of Engineering
UCSC
_______________________________________________
Tinyos-help mailing list
[email protected]
https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help

Reply via email to