ROBOT.LK

I need to make one master wireless digital clock and 20 pieces wireless digital clock as a slave for industrial environment. that clock should cover 1 square kilometer and there are lots of buildings in that premises. so i have to make this clock to function among these building. can you please let me know a better Wireless Transceiver Module to make the digital clock and other supporting clock run well through this obstacle.

Have a look at xBee from Digi. If you are from Sri Lanka, TRONIC.LK has these modules.