[Tinyos-help] TinyOS-2.x Collection Component - no. of children of a given node

[Omprakash Gnawali]

> I'm trying to implement a data aggregation scheme using the collection
> component in tinyos-2.x. Our scheme requires each aggregation node to wait
> for all of its children to respond before performing the computation. Is it
> possible for a node to know as to how many children are currently forwarding
> packets through it. Also, is there a way by which their node id's may also
> be known.


Collection can not tell a node about the number and id's of its
children.

To implement duplicate suppression, the forwarding engine keeps a
small cache of sequence numbers that it has forwarded. In a similar
spirit, you might be able to tweak the forwarding engine to keep a
list of its children as it receives packets from its children. This
will not completely solve all your problems - packets can drop.

- om_p