[Tinyos-devel] [Tinyos-help] Regarding 4 bit link estimation

[Rémi Villé]

2009/7/17 Omprakash Gnawali <gnawali at usc.edu>

> 2009/7/13 Mehmet Akif Antepli <akifantepli at gmail.com>:
> > Hi Omprakash,
> >
> > About the inage field,
> > In the code below, first there is the check for the neighbor table entry
> to
> > update. Inage field is only decremented for the neighbor that sent beacon
> > msg !
> >
> >   // update the inbound link quality by
> >   // munging receive, fail count since last update
> >   void updateNeighborTableEst(am_addr_t n) {
> >     uint8_t i, totalPkt;
> >     neighbor_table_entry_t *ne;
> >     uint8_t newEst;
> >     uint8_t minPkt;
> >     minPkt = BLQ_PKT_WINDOW;
> >     dbg("LI", "%s\n", __FUNCTION__);
> >     for (i = 0; i < NEIGHBOR_TABLE_SIZE; i++) {
> >       ne = &NeighborTable[i];
> >       if (ne->ll_addr == n) {
> >  if (ne->flags & VALID_ENTRY) {
> >    if (ne->inage > 0)
> >      ne->inage--;
> >
> > But i think inage field should be decremented when the following
> condition
> > holds, isn't it?
>
> You caught a bug. This code became a bug when we changed from updating
> all the entries in the link table to selectively updating the link
> table. When all the entries were updated periodically, we would
> decrement the age for all the entries and refresh the age only on the
> entries that were heard from recently. We don't do such wholesome
> periodic updates anymore. Thanks for catching this.
>
> - om_p
>

What could be the bad effect of this bug? Some good neighbors could be
evicted before a whole period?
What is the correct code (maybe on cvs)?
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