Issue link: https://read.uberflip.com/i/1428395
LoRaWAN ® L2 1.0.4 Specification © 2020 LoRa Alliance ® Page 38 of 90 The authors reserve the right to change specifications without notice. reserved for future use. The end-device SHALL check that the frequency is allowed by its radio 1192 hardware and return an error otherwise. 1193 1194 Note: to revert the RX1 frequency to the default value, a Network Server 1195 can send another DlChannelReq with the same value as uplink 1196 frequency. 1197 1198 If the DlChannelReq command is defined in the region where the end-device is operating, the 1199 end-device SHALL acknowledge the receipt of a DlChannelReq by returning a 1200 DlChannelAns command. The DlChannelAns command SHALL be added to the FOpts 1201 field (if FPort is either missing or >0) or to the FRMPayload field (if FPort=0) of all uplinks 1202 until a Class A downlink is received by the end-device. This guarantees that, even in the case 1203 of an uplink frame loss, the Network is always aware of the downlink frequencies used by the 1204 end-device. 1205 The payload of this frame contains the following information: 1206 1207 Size (octets) 1 DlChannelAns payload Status Table 40: DIChannelAns payload format 1208 1209 1210 The status (Status) bits have the following meaning: 1211 1212 Bits 7:2 1 0 Status RFU Uplink frequency exists Channel frequency ok Table 41: Status field format 1213 1214 1215 Bit=0 Bit=1 Channel frequency ok The end-device cannot use this frequency The end-device is able to use this frequency. Uplink frequency exists The uplink frequency is not defined for this channel. The downlink frequency can only be set for a channel that already has a valid uplink frequency The uplink frequency of the channel is valid Table 42: DlChannelAns Status bits signification 1216 1217 1218 If either of those bits equals 0, the command did not succeed, and the end-device SHALL 1219 keep its previous state. 1220