Frequency 868 MHz (ISM range) is increasingly used to build communication systems FSK or LoRA standards.
This is due to its license-free operation provided that the power is not exceeded in 13dBm or 25 milliwatts.
However, for stable operation at large distances, good antennas are required.
And our company offers you to consider the application of the antenna -
LOT-AOF868-001
http://nostris.ee/pdf/lot%20aof868%20001.pdf