Tracking with Xbee

Hello, I would like to design a system for monitoring parameters. The system will be installing in cars or trucks and will measure parameters, like a dataloger, but the data will be downloaded in different parts of the city of wirelessly. My idea is to put differents xbee coordinators in the points where the data can be downloaded.
Then, i have one question:

In xbee network the coordinator has a list of ten end devices, then if a end device is not joined with the coordinator, How does end devices do to transmit the data?


If the End device is not associated with a parent node, then it can’t send the data.