[Tinyos-help] Link Estimation problem on tinynodes

[Omprakash Gnawali]

On Mon, Nov 3, 2008 at 2:13 PM, Jacques Panchard
<jacques.panchard at me.com> wrote:
> Dear Omprakash (Om?),
> Thanks for your answer. I tried 4bitle, but got essentially the same problem
> as with le.
> Looking a little bit at the code, I have the impression that the problem is
> the following:
> - A node updates its parent status whenever receiving a beacon from a
> neighbor, using its sequence number.
> As a consequence, when the connection with the parent is cut abruptly, it
> never receives the next message, and hence the parent gets never updated, so
> the node thinks it is well connected whereas it isn't.
>
> Does that make sense?

When the node tries to send a data packet to the parent and the parent
does not send an ack, the link quality should updated and a new parent
should be selected after a few failed attempts. Do you see txAck and
txNoAck calls you can see in the link estimator? One other possibility
- the parent is actually receiving the message (which is why the
parent does not get updated) but somehow the packet is not reaching
your application. How do you know that the parent is not receiving the
packet?

- om_p