Issue link: https://read.uberflip.com/i/1540208
Regional Parameters RP002-1.0.5 ©2022-2025 LoRa Alliance ® Page 75 of 116 The authors reserve the right to change specifications without notice. 3.10 AS923 MHz Band 1494 3.10.1 AS923 Preamble Format 1495 Refer to Section 5, "Physical Layer". 1496 3.10.2 AS923 Band Channel Frequencies 1497 This section was originally intended to apply to regions where the frequencies [915…928 MHz] 1498 are present in an unlicensed LPWAN band but MAY also apply to regions with available bands 1499 in frequencies up to 1.67 GHz. 1500 In order to accommodate country specific sub-bands across 915 - 928 MHz band, a frequency 1501 offset parameter AS923_FREQ_OFFSET is defined. AS923_FREQ_OFFSET is a 32-bit signed 1502 integer, allowing both positive and negative frequency offsets. 1503 The corresponding frequency offset in Hz is: 1504 AS923_FREQ_OFFSET_HZ = 100 x AS923_FREQ_OFFSET. 1505 AS923_FREQ_OFFSET only applies to end-device default settings. AS923_FREQ_OFFSET 1506 does not apply to any frequencies delivered to the end-device from the Network Server 1507 through MAC commands or the CFList. 1508 AS923 end-devices operated in Japan SHALL perform Listen Before Talk (LBT) based on 1509 ARIB STD-T108 regulations. The ARIB STD-T108 regulation is available for free and should 1510 be consulted as needed by the user. 1511 The end-device's LBT requirement, maximum transmission time, duty cycle, or other 1512 parameters MAY be dependent on frequency of each transmission. 1513 The network channels can be freely assigned by the network operator. However, the two 1514 following default channels SHALL be implemented in every AS923 end-device. Network 1515 gateways SHALL always be listening on one or more of these channels. 1516 1517 Modulation Bandwidth [kHz] Channel Frequency [Hz] LoRa DR / Bitrate Number of Channels Duty Cycle LoRa 125 923200000 + AS923_FREQ_OFFSET_HZ DR0 to DR5 / 0.3-5 kbps 2 < 1% 923400000 + AS923_FREQ_OFFSET_HZ Table 65: AS923 default channels 1518 For devices compliant with [TS001-1.0.x], those default channels SHALL NOT be modified 1519 through the NewChannelReq command. For devices compliant with [TS001-1.1.x] and 1520 beyond, these channels MAY be modified through the NewChannelReq command but SHALL 1521 be reset during the back-off procedure defined in [TS001] to guarantee a minimal common 1522 channel set between end-devices and network gateways. 1523 AS923 end-devices SHALL feature a channel data structure to store the parameters of at least 1524 24 channels. A channel data structure corresponds to a frequency and a set of data rates 1525 usable on this frequency. 1526 1527