Need wireless communication technology options when long range is necessary
You can use Xbee Modules for a wireless communication.
The XBee radios can all be used with the minimum number of connections – power (3.3 V), ground, data in and data out (UART), with other recommended lines being Reset and Sleep.[5] Additionally, most XBee families have some other flow control, I/O, A/D and indicator lines built in.