Hello
I'm thinking of putting some Arduinos (Arduino + sensor (like temperature)) at some points of a zone (like city) (separated by 1 km) ...
I need the link all to get the data collected ..
The problem is the range and/or cost of models GSM / WIFI / ZIGBEE ...
I was thinking to connect these devices via RADIO 
!? ?!?!? 
Do you know any solution to this problem?
Thanks
Many questions pop up:
You want to have the data real time?
Is there line of sight between the nodes?
How much data per second per node do you expect?
How much nodes are there?
Are the nodes identical?
Are the nodes inside or outside?
Is there an open network in the neighbourhood you are allowed to use?
robtillaart:
Many questions pop up:
You want to have the data real time?
-> YES and NO .... I need detect problems ... if I detect problems sooner lose less money ..
Is there line of sight between the nodes?
-> No!!
How much data per second per node do you expect?
I need to read a temperature sensor (for example) and get the data (the speed is not important)!.
How much nodes are there?
-> one between 500 to 1000 meters
Is there an open network in the neighbourhood you are allowed to use?
No...
MeshNet using Xbees is your best bet, not very cheapo but incredibly effective. Plus, Digi`s tech supports (chat) is A W E S O M E!!!!