I am using BRD4257B module. What is the best settings (radio profile, radio PHY) for maximum communication range in 868MHz band? I have small packet to transmit.
Do you have a desire modulation and desire range?
thank you for answer. According to:
it is possible to achieve 2700 m for 868MHz with 2GFSK 2.4 kbps 1.2 kHz. I have tested Connect profile with 2GFSK 100kbps. The range was about 200 m. There is 2GFSK 2.4kbps 1.2k in Basic profile. But I could not run it.
Except that I noticed long range settings for 915MHz OQPSK 1p2kbps 2p4k (only in Flex SDK 2.5.5, not in 2.6.1). Are there similar for 868MHz?
long range communication requires narrow channel bandwidth in general, which means the frequency offset tolerance will also become a dominant factor beside the receiver's sensitivity, therefore very accurate clock reference and/or Rx/Tx synchronization will be needed for such a link. The 2GFSK 100 kbps PHY you mentioned is a fairly wide band in this regard and will work out of the box with our dev boards, but the 2.4 kbps probably wont because of the frequency offset between dev boards. So I guess that could be the problem with the 2.4 kbps in your test.
About the OQPSK variant you shall see https://www.silabs.com/community/wireless/proprietary/forum.topic.html/oqpsk_long_ranger-LzGs.