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TS001-1.0.4 LoRaWAN® L2 1.0.4 Specification

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LoRaWAN ® L2 1.0.4 Specification © 2020 LoRa Alliance ® Page 68 of 90 The authors reserve the right to change specifications without notice. The Param bits have the following meaning, where Prec encodes the timing precision of the 2047 beacon: 2048 2049 Bits 7:2 1:0 Param RFU Prec Table 75: Param bits 2050 2051 2052 The precision is interpreted as a base-ten exponent of the beacon's transmit time precision 2053 10 (−6+ Prec ) s, where the default value of Prec is 0. The Prec field can take any value within 2054 the range [0:3]. The RFU portion of Param SHALL be set to 0 and the end-device SHALL 2055 silently ignore this field. Networks that use a beacon precision value other than 0 for Prec 2056 SHOULD send the beacon using a non-default value of BeaconFrequency. 2057 The common part MAY contain an RFU field equal to 0. It also contains a Param including 2058 timestamp precision Prec and a timestamp Time expressed in seconds elapsed since 2059 January 6, 1980 00:00:00 UTC (start of the GPS epoch) modulo 2 32 . The integrity of the 2060 beacon's network common part is protected by a 16-bit CRC. The value of CRC-16 SHALL be 2061 computed on the RFU + Param + Time fields as defined in IEEE 802.15.4-2003, Section 2062 13.4. This CRC SHALL use the polynomial P(x) = x 16 + x 12 + x 5 + x 0 . The CRC SHALL be 2063 calculated on the octets in the order they are sent over the air. 2064 13.3 Beacon GwSpecific Field Format 2065 The content of the GwSpecific field is 2066 2067 Size (octets) 1 6 GwSpecific InfoDesc Info Table 76: Beacon GwSpecific field format 2068 2069 2070 2071 The information descriptor InfoDesc describes how the information field Info SHALL be 2072 interpreted. 2073 2074 InfoDesc Meaning 0 GPS coordinate of the gateway first antenna 1 GPS coordinate of the gateway second antenna 2 GPS coordinate of the gateway third antenna 3 NetID + GatewayID 4:127 RFU 128:255 Reserved for custom network-specific broadcasts Table 77: Beacon InfoDesc index mapping 2075 2076 2077

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