Issue link: https://read.uberflip.com/i/1428383
LoRaWAN 1.0.3 Specification ©2018 LoRa™ Alliance Page 28 of 72 The authors reserve the right to change specifications without notice. 5.6 Creation / Modification of a Channel (NewChannelReq, 768 NewChannelAns, DlChannelReq, DlChannelAns) 769 770 The NewChannelReq command can be used to either modify the parameters of an existing 771 bidirectional channel or to create a new one. The command sets the center frequency of the 772 new channel and the range of uplink data rates usable on this channel: 773 Size (bytes) 1 3 1 NewChannelReq Payload ChIndex Freq DrRange 774 The channel index (ChIndex) is the index of the channel being created or modified. Depending 775 on the region and frequency band used, the LoRaWAN specification imposes default channels 776 which MUST be common to all devices and cannot be modified by the NewChannelReq 777 command (cf. Chapter 6). If the number of default channels is N, the default channels go from 778 0 to N-1, and the acceptable range for ChIndex is N to 15. A device MUST be able to handle 779 at least 16 different channel definitions. In certain region the device may have to store more 780 than 16 channel definitions. 781 782 The frequency (Freq) field is a 24 bits unsigned integer. The actual channel frequency in Hz 783 is 100 x Freq whereby values representing frequencies below 100 MHz are reserved for future 784 use. This allows setting the frequency of a channel anywhere between 100 MHz to 1.67 GHz 785 in 100 Hz steps. A Freq value of 0 disables the channel. The end-device has to check that the 786 frequency is actually allowed by its radio hardware and return an error otherwise. 787 788 The data-rate range (DrRange) field specifies the uplink data-rate range allowed for this 789 channel. The field is split in two 4-bit indexes: 790 Bits 7:4 3:0 DrRange MaxDR MinDR 791 Following the convention defined in Section 5.2 the minimum data rate (MinDR) subfield 792 designate the lowest uplink data rate allowed on this channel. For example 0 designates DR0 793 / 125 kHz. Similarly, the maximum data rate (MaxDR) designates the highest uplink data rate. 794 For example, DrRange = 0x77 means that only 50 kbps GFSK is allowed on a channel and 795 DrRange = 0x50 means that DR0 / 125 kHz to DR5 / 125 kHz are supported. 796 The newly defined or modified channel is enabled and can immediately be used for 797 communication. The RX1 downlink frequency is set equal to the uplink frequency. 798 The end-device acknowledges the reception of a NewChannelReq by sending back a 799 NewChannelAns command. The payload of this message contains the following information: 800 Size (bytes) 1 NewChannelAns Payload Status 801 The status (Status) bits have the following meaning: 802 Bits 7:2 1 0 Status RFU Data rate range ok Channel frequency ok 803 Bit = 0 Bit = 1 Data rate range ok The designated data rate range exceeds the ones The data rate range is compatible with the