Issue link: https://read.uberflip.com/i/1428362
LoRaWAN 1.0.2 Regional Parameters ©2017 LoRa Alliance™ Page 41 of 55 The authors reserve the right to change specifications without notice. 2.7.6 AS923 Maximum payload size 1080 The maximum MACPayload size length (M) is given by the following table for both dwell 1081 time configurations: No Limit and 400ms. It is derived from the PHY layer limitation 1082 depending on the effective modulation rate used taking into account a possible repeater 1083 encapsulation layer. 1084 1085 DataRate Uplink MAC Payload Size (M) Downlink MAC Payload Size (M) UplinkDwellTime = 0 UplinkDwellTime = 1 DownlinkDwellTime = 0 DownlinkDwellTime = 1 0 59 N/A 59 N/A 1 59 N/A 59 N/A 2 59 19 59 19 3 123 61 123 61 4 230 133 230 133 5 230 250 230 250 6 230 250 230 250 7 230 250 230 250 8:15 RFU RFU Table 53: AS923 maximum payload size 1086 If the end-device will never operate with a repeater then the maximum MAC payload length 1087 should be: 1088 DataRate Uplink MAC Payload Size (M) Downlink MAC Payload Size (M) UplinkDwellTime = 0 UplinkDwellTime = 1 DownlinkDwellTime = 0 DownlinkDwellTim e = 1 0 59 N/A 59 N/A 1 59 N/A 59 N/A 2 59 19 59 19 3 123 61 123 61 4 250 133 250 133 5 250 250 250 250 6 250 250 250 250 7 250 250 250 250 8:15 RFU RFU Table 54: AS923 maximum payload size (not repeater compatible) 1089 The maximum application payload length in the absence of the optional FOpt control field 1090 (N) is eight bytes lower than the MACPayload value in the above table. The value of N might 1091 be smaller if the FOpt field is not empty. 1092 1093 2.7.7 AS923 Receive windows 1094 The RX1 receive window uses the same channel than the preceding uplink. The data rate is 1095 a function of the uplink data rate and the RX1DROffset as following: 1096 Downstream data rate in RX1 slot = MIN (5, MAX (MinDR, Upstream data rate – 1097 Effective_RX1DROffset)) 1098 MinDR depends on the DownlinkDwellTime bit sent to the device in the TxParamSetupReq 1099 command: 1100 Case DownlinkDwellTime = 0 (No limit): MinDR = 0 1101 Case DownlinkDwellTime = 1 (400ms): MinDR = 2 1102 The allowed values for RX1DROffset are in the [0:7] range, encoded as per the below table: 1103