XBee roaming?

[konfu]

Hi folks,

I am trying to understand XBee/Zigbee for quite some time now but something I just can't find an answer on:

Given a Zigbee network based on Digi's XBee modules. One coordinator, four routers, one end-device. The network is build over a larger area. The coordinator right in the middle and each router around him to extend the range. just as one in the north, one in the south, one east and one west. The covered area is large enough the end-device can not see more than two other devices at the same time.

If I now move the ED around. Move it from the range of router 1 (its parent) to the range of router 3. can it still reach the coordinator? so does the ED support something like roaming?

From what I've read so far: when the ED joins the network in the 1st place it will pick a parent (either a router or the coordinator, whatever is closest). If that parent is not in range anymore but another router is. what is going to happen? can the ED and the coordinator still talk to each other? what if the ED slept for a minute and wakes up in the range of another router only?


I know I could just go out and buy some modules to just test it. But I don't have the money yet so I want to understand Zigbee before actually spend money on it.