Issue link: https://read.uberflip.com/i/1428395
LoRaWAN ® L2 1.0.4 Specification © 2020 LoRa Alliance ® Page 45 of 90 The authors reserve the right to change specifications without notice. 6.2.5 Join-Request frame 1427 The Join procedure is always initiated by the end-device sending a Join-Request frame. 1428 1429 Size (octets) 8 8 2 Join-Request payload JoinEUI DevEUI DevNonce Table 53: Join-Request payload format 1430 1431 1432 The Join-Request frame contains the JoinEUI and DevEUI of the end-device followed by 1433 a nonce of 2 octets (DevNonce). 1434 DevNonce is a counter starting at 0 when the end-device is initially powered up and 1435 incremented with every Join-Request. A DevNonce value SHALL never be reused for a given 1436 JoinEUI value. If the end-device can be power-cycled, then DevNonce SHALL be 1437 persistent (e.g., stored in a non-volatile memory). Resetting DevNonce without changing 1438 JoinEUI will cause the Join Server to discard the Join-Requests of the end-device. For each 1439 end-device, the Join Server keeps track of the last DevNonce value used by the end-device 1440 and ignores Join-Requests if DevNonce is not incremented. 1441 The message integrity code (MIC) value (see Section 4 for MAC frame description) for a Join- 1442 Request frame SHALL be calculated as follows: 9 1443 1444 CMAC = aes128_cmac(AppKey, MHDR | JoinEUI | DevEUI | DevNonce) 1445 MIC = CMAC[0..3] 1446 The Join-Request frame is not encrypted. 1447 The Join-Request frame MAY be transmitted using any data rate and following a random 1448 frequency-hopping sequence across the specified Join channels. Join-Request transmission 1449 PHY requirements can be region-specific and are detailed in [RP002]. If Join-Request 1450 transmission PHY parameters are not available in [RP002], end-devices SHALL transmit Join- 1451 Requests across all available channels at the lowest required data rate for the region. 1452 Additionally, end-devices SHOULD transmit Join-Requests across all available channels at all 1453 required data rates for that region. The intervals between transmissions of Join-Requests 1454 SHALL respect the conditions described in Section 7. For each transmission of a Join- 1455 Request, the end-device SHALL increment the DevNonce value. 1456 6.2.6 Join-Accept frame 1457 The Network SHALL respond to a Join-Request frame with a Join-Accept frame if the end- 1458 device is permitted to join the network. The Join-Accept frame is sent like a normal downlink 1459 but uses delays JOIN_ACCEPT_DELAY1 or JOIN_ACCEPT_DELAY2 (instead of 1460 RECEIVE_DELAY1 and RECEIVE_DELAY2, respectively). The channel frequency and data 1461 rate used for these two receive windows are identical to the ones used for the RX1 and RX2 1462 receive windows described in Section 3.3 and SHALL use the default values defined in the 1463 Regional Parameters [RP002] specification. 1464 A Join-Accept response SHALL NOT be given to the end-device if the Join-Request is not 1465 accepted. 1466 9 [RFC4493]