Issue link: https://read.uberflip.com/i/1464682
LoRaWAN ® Application Layer Clock Synchronization Specification TS003-2.0.0 ©2022 LoRa Alliance ® Page 6 of 13 The authors reserve the right to change specifications without notice. 3 Clock Synchronization Message Package 161 162 The PackageIdentifier of the clock synchronization package is 1. The 163 PackageVersion of this package is version 2. This version of the package is not 164 compatible with the earlier version of the same package. 165 166 The following messages are sent to/from each end-device individually, using unicast uplink 167 or downlink on a port specifically used for the clock synchronization package. It is 168 RECOMMENDED that a default port value of 202 be used to promote interoperability, 169 though implementations MAY use a value from those not assigned by the LoRa Alliance. 170 These messages SHALL NOT be sent using multicast. If these messages are received on a 171 multicast address, the end-device SHALL drop them silently. 172 173 All unicast control messages use the same format: 174 Command1 Command1 Payload Command2 Command2 payload …. Table 1: Format of control messages 175 A message MAY carry more than one command. The length of each command's payload is 176 fixed and a function of the command. The end-device SHALL execute the commands in 177 sequence, starting from the first one. Each command SHALL be individually acknowledged 178 by the end-device on the same port field (FPort). 179 180 The following table summarizes the list of the clock synchronization messages: 181 182 CID Command name Transmitted by Short Description End- device App Server 0x00 PackageVersionReq x Used by the Application Server to request the package version implemented by the end-device 0x00 PackageVersionAns x Conveys the answer to PackageVersionReq 0x01 AppTimeReq x Used by the end-device to request a clock correction 0x01 AppTimeAns x Conveys the clock timing correction 0x02 DeviceAppTimePeriodicityReq x Used by the Application Server for two purposes: • Sets the periodicity, at which the end-device shall transmit AppTimeReq messages • Requests an immediate transmission of end-device time 0x02 DeviceAppTimePeriodicityAns x Conveys the answer to DeviceAppTimePeriodicityReq 0x03 ForceDeviceResyncCmd x Sent by the Application Server to the end-device to trigger a clock resynchronization Table 2: Summary of clock synchronization messages 183