| Range claim | Wi-Fi HaLow range | Wi-Fi Alliance materials describe Wi-Fi HaLow as capable of reaching more than 1 km in suitable conditions. | Treat 1 km+ as a capability claim, not a guaranteed indoor, outdoor, or device-to-device coverage distance. Verify the actual installation with a site survey. |
| Frequency | Operating band | Wi-Fi HaLow (IEEE 802.11ah) operates in sub-1 GHz spectrum. The specific permitted frequencies depend on the country or region. | Check the device’s supported regional band and local radio regulations before purchase. Devices for different regions may not be interchangeable. |
| Propagation comparison | Free-space path loss at 1 km | At 915 MHz: approximately 91.7 dB. At 2.4 GHz: approximately 100.0 dB. | Under free-space assumptions, the 915 MHz signal has about 8.4 dB less path loss at the same distance. This comparison does not account for walls, foliage, interference, or antenna placement. |
| Illustrative link budget | Assumed radio and antenna inputs | Transmit power: 20 dBm; transmitting antenna gain: 2 dBi; receiving antenna gain: 2 dBi; combined cable and connector loss: 1 dB; receiver sensitivity: −95 dBm. | These are example inputs for calculation only, not specifications for a typical or particular product. Use the selected device’s datasheet values, measured at the intended channel width and data rate. |
| Illustrative link budget | Maximum path loss with fade margin | With a 15 dB fade margin: 20 + 2 + 2 − 1 − (−95) − 15 = 103 dB allowable path loss. | The fade margin provides room for changes in signal level. Increase it when the link must tolerate variable weather, moving obstacles, or changing installation conditions. |
| Illustrative link budget | 915 MHz, 1 km free-space check | Allowable path loss: 103 dB. Estimated free-space path loss: 91.7 dB. Remaining margin: approximately 11.3 dB. | This simplified example clears the assumed 15 dB design-margin calculation at 1 km only under the stated inputs and free-space model. Real terrain and obstacles can consume the remaining margin. |
| Receiver sensitivity | What to compare on datasheets | Sensitivity varies with channel width, modulation and coding rate, and device implementation. A single sensitivity number is not meaningful without its associated PHY mode. | Compare sensitivity at the same channel width and data rate. Lower (more negative) dBm values indicate the receiver can detect weaker signals under the stated test conditions. |
| Channel width | Bandwidth versus range and throughput | IEEE 802.11ah supports channel widths including 1, 2, 4, 8, and 16 MHz; regional rules and product support determine which are usable. | Narrower channels can help a link budget in some configurations but generally limit peak throughput. Confirm supported widths, regional availability, and required application data rate. |
| Antenna and installation | Practical link factors | Antenna orientation, height, enclosure materials, cable loss, obstructions, and interference can materially change received signal level. | Check antenna options and connector details. Test with the final enclosure and mounting position rather than relying only on a module’s laboratory figures. |
| Selection checklist | Minimum comparison set | Regional band; transmit power and regulatory limits; antenna gain; receiver sensitivity by PHY mode; supported channel widths; power consumption; and security support. | Choose the device that meets the application’s throughput and power needs while retaining a measured link margin at the farthest required point. |
| Calculation note | Free-space path-loss formula | FSPL (dB) = 32.44 + 20 log10(frequency in MHz) + 20 log10(distance in km). | Free-space path loss is a comparison baseline, not a field-coverage prediction. Link-budget examples are illustrative and should be validated through deployment testing. |