Issue link: https://read.uberflip.com/i/1428383
LoRaWAN 1.0.3 Specification ©2018 LoRa™ Alliance Page 51 of 72 The authors reserve the right to change specifications without notice. 14.3 PingSlotChannelReq 1351 This command is sent by the server to the end-device to modify the frequency and/or the data 1352 rate on which the end-device expects the downlink pings. 1353 This command can only be sent in a class A receive window (following an uplink). The 1354 command SHALL NOT be sent in a class B ping-slot. If the device receives it inside a class B 1355 ping-slot, the MAC command SHALL NOT be processed. Once the NS has sent the first 1356 PingSlotChannelReq command, it SHOULD resend it until it receives a PingSlotChannelAns 1357 from the device. It MUST NOT attempt to use a class B ping slot until it receives the 1358 PingSlotChannelAns. 1359 1360 Octets 3 1 PingSlotChannelReq Payload Frequency DR Figure 18 : PingSlotChannelReq payload format 1361 The Frequency coding is identical to the NewChannelReq MAC command defined in the 1362 Class A. 1363 Frequency is a 24bits unsigned integer. The actual ping channel frequency in Hz is 100 x 1364 frequ. This allows defining the ping channel anywhere between 100MHz to 1.67GHz by 100Hz 1365 step. The end-device has to check that the frequency is actually allowed by its radio hardware 1366 and return an error otherwise. 1367 A value of 0 instructs the end-device to use the default frequency plan. Where applicable the 1368 device resumes frequency hopping beacon search. 1369 The DR byte contains the following fields: 1370 1371 Bits 7:4 3:0 DR RFU data rate 1372 The "data rate" subfield is the index of the Data Rate used for the ping-slot downlinks. The 1373 relationship between the index and the physical data rate is defined in [PHY] for each region. 1374 Upon reception of this command the end-device answers with a PingSlotFreqAns message. 1375 The MAC payload of this message contains the following information: 1376 1377 Size (bytes) 1 pingSlotFreqAns Payload Status Figure 19 : PingSlotFreqAns payload format 1378 The Status bits have the following meaning: 1379 Bits 7:2 1 0 Status RFU Data rate ok Channel frequency ok 1380 Bit = 0 Bit = 1 Data rate ok The designated data rate is not defined for this end device, the previous data rate is kept The data rate is compatible with the possibilities of the end device