This question starts out pretty broad, then I'll be more specific later:
What would be the easiest wireless format to use to transmit simple status messages from nodes to a central monitor and back? The central node would be an arduino/sanguino. The messages would be sent in a round robin fashion to the hub with the interrupt if status(es) change:
Example (simplified)
Node 1 check in... no change... Heard...
(3 secs)
Node 2 check in... no change... Heard...
(3 secs)
Node 3 check in... no change... Heard...
(3 secs)
Node 1 check in... no change... Heard...
NODE 2 SIGNAL... Alert... Heard...
NODE 2 SIGNAL... Alert... Heard...
NODE 2 SIGNAL... Alert... Heard...
Any ideas would be greatly appreciated!