proper wireless communication

Hi!

I want to make two Arduinos talk to each other wirelessly with XBees or my latest find; the DNT24: DNT24 - Networking, Protocols, and Devices - Arduino Forum

Since reception will not always be good and amount of data could be large, I need to make sure that the data is correct. How do I manage proper wireless communication? I could send something from A to B, B reports to A what it received and A confirms the correctness of the message. Or are the devices managing this themselfes?

Another short question, not worth an own thread: Can I send something with an XBee (broadcast) and two devices receive this message? Or is this like Serial connection with the computer where always only one program can receive and connect to the data?

Thanks!

How do I manage proper wireless communication? I could send something from A to B, B reports to A what it received and A confirms the correctness of the message. Or are the devices managing this themselfes?

The XBees, if you use API mode, take care of that. In AT mode, you have to.
Using the other devices, they may or may not.

Can I send something with an XBee (broadcast) and two devices receive this message?

Of course. That is what broadcast mode is for.