Wireless Switch

Hello, I found this page: http://www.wirelessirrigation.com/sensors.html
They have a wireless switch and the battery will last for several years. I wondered how you could do this. I know the Xbee technology but it has a big consumption so that the battery will last as long.
The only way to use Xbee devices is sleeping the devices but then the switch does not open or closes instantly.

Then, How can I make it?

Thanks,
Regards.

First of all, the battery doesn't seem to be an AA-type of battery but some bigger high capacity model. Where do you have the information from, that the switch acts instantly? It's stated that the control is real time but that not an exact time definition. In this context it could mean that the control is central and you don't have to go around to update sprinkler plan at every sprinkler location. But if the sprinkler needs 30 seconds to react on a command it's probably acceptable in most cases. If a system can sleep for 30 seconds, listen to a radio transceiver for 10ms and go to sleep again for 30 seconds, it's not that extraordinarily difficult for the batteries to last a few years.
XBee is probably not the technology for such situations but that's the reason they built their own radio system.

I'll try to do with XBee, the system will sleep 30 seconds and 10ms awake.
Thanks,
Regards.