3.4. Convergence Time
A wireless home automation network is subject to various
instabilities due to signal strength variation, moving persons, and
the like.
Measured from the transmission of a packet, the following convergence
time requirements apply.
The routing protocol MUST converge within 0.5 seconds if no nodes
have moved (see Section 3.2 for motivation).
The routing protocol MUST converge within four seconds if nodes have
moved to re-establish connectivity within a time that a human
operator would find tolerable as, for example, when moving a remote
control unit.
In both cases, "converge" means "the originator node has received a
response from the destination node". The above-mentioned convergence
time requirements apply to a home control network environment of up
to 250 nodes with up to four repeating nodes between source and
destination.