Issue link: https://read.uberflip.com/i/1428395
LoRaWAN ® L2 1.0.4 Specification © 2020 LoRa Alliance ® Page 67 of 90 The authors reserve the right to change specifications without notice. 13 Class B Beaconing 2024 13.1 Beacon Physical Layer 2025 In addition to relaying frames between end-devices and Network Servers, gateways MAY 2026 participate in providing a time-synchronization mechanism by sending beacons at regular fixed 2027 intervals. All beacons are transmitted in radio packet implicit mode, that is, without a LoRa 2028 physical header and with no CRC appended by the radio. 2029 2030 2031 PHY Preamble BCNPayload Table 73: Beacon physical format 2032 2033 2034 The beacon Preamble SHALL begin with (a longer than default) 10 unmodulated symbols. 2035 This allows end-devices to implement a low power duty-cycled beacon search. 2036 The beacon frame length is tightly coupled to the operation of the radio physical layer. 2037 Therefore, the actual frame length and content changes from one region implementation to 2038 another. The beacon content, modulation parameters and frequencies are specified in 2039 [RP002] for each region. 2040 13.2 Beacon Frame Format 2041 The beacon payload BCNPayload consists of a network common part and an OPTIONAL 2042 gateway-specific part. 2043 2044 2045 Table 74: Beacon frame content 2046 SF 8 Size (octets) 1 4 2 7 3 2 BCNPayload Param Time CRC GwSpecific RFU CRC SF 9 Size (octets) 1 1 4 2 7 2 BCNPayload RFU Param Time CRC GwSpecific CRC SF 10 Size (octets) 2 1 4 2 7 1 2 BCNPayload RFU Param Time CRC GwSpecific RFU CRC SF 11 Size (octets) 3 1 4 2 7 2 2 BCNPayload RFU Param Time CRC GwSpecific RFU CRC SF 12 Size (octets) 4 1 4 2 7 3 2 BCNPayload RFU Param Time CRC GwSpecific RFU CRC