[werk_ag]

...  So 3 seconds is already rather fast and 1 second would probably "kill" most of the other available systems, because of all the "collisions" between data packets from different sources.

I think you are right, Alan. Besides the possibility to "kill" other existing systems, it also will "kill" WeatherDuino systems that are using two or more TX units.

I don't know how the Weatherduino data/protocol is organised,...

WeatherDuino uses one data packet for each type of data. The data packet with Wind data (which includes Gust, 2 min average speed, 10 min average speed and direction)  is the only one that is sent at each 3 seconds. Rain is sent at each 31 seconds, and the others a little more. The interval between data packets was chose using prime numbers to minimize collisions, which as proven to work very well specially when there is just one transmitter unit. When there is more than one TX unit, obviously the probability of collision increases, but even with four units (maximum allowed) its possible to run a very reliable system, specially because when a user uses more than one TX unit, usually each unit do not send all the types of data packets. Per example, one sends data from instruments that should be placed at above the roof level (as is the case of the anemometers), and the other TX units send data from instruments that usually are placed more near the ground level (as is the case of the rain gauge, and temperature / humidity sensors).

Hope my poor English was enough to make my writing understandable.