Issue link: https://read.uberflip.com/i/1479525
LoRaWAN® Regional Parameters RP002-1.0.4 ©2022 LoRa Alliance ® Page 40 of 101 The authors reserve the right to change specifications without notice. 2.5.5 US902-928 LinkADRReq Command 744 The US902-928 channel plan of LoRaWAN supports a minimum of 72 and a maximum of 80 745 channels. The ChMaskCntl field of the LinkADRReq command has the following meaning: 746 747 ChMaskCntl ChMask Applies To 0 Channels 0 to 15 1 Channels 16 to 31 2 Channels 32 to 47 3 Channels 48 to 63 4 Channels 64 to 79 5 10 LSBs control channel blocks 0 to 9 (6 MSBs are RFU) 6 All default 125 kHz ON: ChMask applies to channels 64 to 79 7 All default 125 kHz OFF: ChMask applies to channels 64 to 79 Table 18: US902-928 ChMaskCntl value 748 If ChMaskCntl = 5 19 , bits 0-7 in the ChMask enable and disable a bank of eight 125 kHz 749 channels and the corresponding 500 kHz channel defined by the following calculation: 750 [ChannelMaskBit * 8, ChannelMaskBit * 8 +7],64+ChannelMaskBit. Bits 8 and 9 in the 751 ChMask enable and disable a bank of eight channels defined by the following calculation: 752 [ChannelMaskBit * 8, ChannelMaskBit * 8 +7]. 753 If ChMaskCntl = 6, all 125 kHz channels are enabled. If ChMaskCntl = 7, all 125 kHz 754 channels are disabled. Simultaneously, the channels 64 to 71 are set according to the ChMask 755 bit mask. The data rate specified in the command need not be valid for channels specified in 756 the ChMask, as it governs the global operational state of the end-device. 757 Notes: 758 - FCC regulation requires hopping over at least 50 channels when using 759 maximum output power. This is achieved either when more than 50 760 LoRa/125 kHz channels are enabled and/or when at least one LR-FHSS 761 channel is enabled. It is possible to have end-devices with less channels 762 when limiting the conducted transmit power of the end-device to 21 763 dBm. 764 - A common Network Server action may be to reconfigure a device 765 through multiple LinkADRReq commands in a contiguous block of MAC 766 commands. For example, to reconfigure a device from 64 channel 767 operation to the first 8 channels could contain two LinkADRReq 768 commands, the first (ChMaskCntl = 7) to disable all 125 kHz channels 769 and the second (ChMaskCntl = 0) to enable a bank of 8 125 kHz 770 channels. Alternatively, using ChMaskCntl = 5, a device can be re- 771 configured from 64 channel operation to support the first 8 channels in 772 a single LinkADRReq. 773 774 2.5.6 US902-928 Maximum Payload Size 775 The maximum MACPayload size length (M) is given by the following table. It is derived from 776 the maximum allowed transmission time at the PHY layer, taking into account a possible 777 repeater encapsulation. The maximum application payload length in the absence of the 778 OPTIONAL FOpts MAC control field (N) is also given for information only. The value of N 779 MAY be smaller if the FOpts field is not empty. 780 19 Added in LoRaWAN Regional Parameters Specification version 1.0.3rA.