Issue link: https://read.uberflip.com/i/1428395
LoRaWAN ® L2 1.0.4 Specification © 2020 LoRa Alliance ® Page 31 of 90 The authors reserve the right to change specifications without notice. 949 950 In the Redundancy bits, the NbTrans field is the number of transmissions for each uplink 951 frame. This applies to both confirmed and unconfirmed uplink frames. The default value is 1, 952 which corresponds to a single transmission of each frame. The valid range is [1:15]. If an 953 NbTrans value of 0 is received, the end-device SHALL use the default value. This field MAY 954 be used by a Network Server to control the redundancy of the uplink transmissions 955 (retransmissions) to obtain a given quality of service. The end-device performs frequency 956 hopping for retransmissions as usual, and it waits as usual after each retransmission until RX2 957 has expired. Whenever a downlink frame is received during either RX1 or RX2, the end-device 958 SHALL stop any further retransmission of that same uplink frame. 959 The channel mask control (ChMaskCntl) field controls the interpretation of the previously 960 defined ChMask bit mask. It controls the block of 16 channels to which the ChMask applies. 961 It can also be used to turn all channels on or off globally using a specific modulation. The 962 meaning of ChMaskCntl is region-specific and defined in the "LoRaWAN Regional 963 Parameters" [RP002] document. 964 A Network Server MAY include multiple LinkADRReq commands within a single downlink 965 frame. For the purpose of configuring the end-device channel mask, the end-device SHALL 966 process all contiguous LinkADRReq commands in the order present in the downlink frame as 967 a single atomic block command. The end-device SHALL accept or reject all Channel Mask 968 controls in the contiguous block and SHALL provide consistent channel mask ACK status 969 indications for each command in the contiguous block in each LinkADRAns command, 970 reflecting the acceptance or rejection of this atomic channel mask setting. The end-device 971 SHALL only process the DataRate, TXPower and NbTrans from the last LinkADRReq 972 command in the contiguous block, as these settings govern the end-device global state for 973 these values. The end-device SHALL provide consistent ACK status in each LinkADRAns 974 command reflecting the acceptance or rejection of these final settings. 975 The channel frequencies are region-specific and defined [RP002]. An end-device SHALL 976 answer a LinkADRReq with a LinkADRAns command. 977 978 979 Size (octets) 1 LinkADRAns payload Status Table 21: LinkADRAns payload format 980 981 982 983 Bits [7:3] 2 1 0 Status RFU PowerACK DataRateACK ChannelMaskACK Table 22: Status field format 984 985 986 987 988 989 990 991 992