2008/3/18 jiwen zhang <[EMAIL PROTECTED]>:
> Hell ：
> Thank you for your answer to my questions , Om_p.
> I still have some questions :
>
>
> 1. what are uses of the inage and outage defined in struct
> neighbor_table_entry in LinkEstimator.h? in file LinkEstimatorP.nc, it
> defines MAX_AGE=6,which is "maximum link update rounds before we expire the
> link". i want to know what is the meaning of "link update rounds" ?
After a certain time has passed or certain number of beacons, we
accumulate enough information to update the link quality estimate.
That is one round of update. Again, we wait and collect more
information for a while and update the estimate. That is the second
round. etc.
> 2.In LInkEstimatorP.nc,there are some functions :
> void updateEETX(neighbor_table_entry_t *ne, uint16_t newEst) {
> ne->eetx = (ALPHA * ne->eetx + (10 - ALPHA) * newEst)/10;
> }
This is exponential averaging.
....
>
> I can't understand the arithmetic used in the functions such as "ne->eetx =
> (ALPHA * ne->eetx + (10 - ALPHA) * newEst)/10" in updateEETX ,"estETX =
> (ne->data_total - 1)* 10" " estETX = (10 * ne->data_total) /
> ne->data_success - 10" in updateDEETX and others in computeEETX and
> computeBidirEETX. i think there should be some reasons why they write the
> programem link that. can someone give me a detail explains or give me a clue
> where i can find the reason ?
updateDEETX computes the ETX estimate from data transmission statistics.
computeEETX and computeBidirEETX do the computation that is described
in the comment that appears just before those functions.
- om_p
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