Issue link: https://read.uberflip.com/i/1428371
LoRaWAN Regional Parameters ©2016 LoRa™ Alliance Page 21 of 45 The authors reserve the right to change specifications without notice. 2.4 EU 433MHz ISM Band 1 2.4.1 EU433 Preamble Format 2 The following synchronization words should be used : 3 4 Modulation Sync word Preamble length LORA 0x34 8 symbols GFSK 0xC194C1 5 bytes Table 21: EU433 synch words 5 2.4.2 EU433 ISM Band channel frequencies 6 The LoRaWAN can be used in the ETSI 433-434 MHz band as long as the radio device ERP 7 is less than 10 mW (or 10 dBm). 8 The end-device transmit duty-cycle should be lower than 1% 1 . 9 The LoRaWAN channels center frequency can be in the following range: 10 Minimum frequency : 433.175 MHz 11 Maximum frequency : 434.665 MHz 12 EU433 end-devices should be capable of operating in the 433.05 to 434.79 MHz frequency 13 band and should feature a channel data structure to store the parameters of at least 16 14 channels. A channel data structure corresponds to a frequency and a set of data rates 15 usable on this frequency. 16 The first three channels correspond to 433.175, 433.375 and 433.575 MHz with DR0 to DR5 17 and must be implemented in every end-device. Those default channels cannot be modified 18 through the NewChannelReq command and guarantee a minimal common channel set 19 between end-devices and gateways of all networks. Other channels can be freely distributed 20 across the allowed frequency range on a network per network basis. 21 The following table gives the list of frequencies that should be used by end-devices to 22 broadcast the JoinReq message. The JoinReq message transmit duty-cycle shall follow the 23 rules described in chapter "Retransmissions back-off" of the LoRaWAN specification 24 document. 25 26 Modulation Bandwidth [kHz] Channel Frequency [MHz] FSK Bitrate or LoRa DR / Bitrate Nb Channels Duty cycle LoRa 125 433.175 433.375 433.575 DR0 – DR5 / 0.3-5 kbps 3 <1% Table 22: EU433 JoinReq Channel List 27 1 The EN300220 ETSI standard limits to 10% the maximum transmit duty-cycle in the 433MHz ISM band. The LoRaWAN requires a 1% transmit duty-cycle lower than the legal limit to avoid network congestion.