I have an application that is battery powered. It may need to sit there, waiting for a wireless query, for several months. Wake up (that is, initial connection time) can be very slow, perhaps as long as several seconds. Operating distance needs to be no more than 50m.
So, I am looking for something which has either a very low receive current or which has an effective "receive sleep" mode, waking periodically to check for a received signal.
This device needs to work in one of the international ISM bands. Data rate does not have to be terribly fast.
I'd appreciate any recommendations.