--- title: "Kilometres on a coin cell | Nexus Observatory" description: "Most environmental sensors send a few bytes a few times an hour. Low-power wide-area networks trade bandwidth for range and battery life…" url: https://observatory.global/stories/lpwan-mesh/ publisher: Nexus Observatory Inc. updated: 2026-10-31 --- [Stories](https://observatory.global/stories/)System: LPWAN and mesh # Kilometres on a coin cell Most environmental sensors send a few bytes a few times an hour. Low-power wide-area networks trade bandwidth for range and battery life; mesh networks trade range for resilience. Both are now international standards12. **Systems**: LPWAN, Mesh, Border routers **Toward 2030**: Satellite IoT in the cellular standard **Figures**: 4, data story, simulator, systems diagram, timeline to 2030 Go to the references **01** Data story ## Spreading factor and airtime. Each step up in spreading factor roughly doubles the time a packet spends on air, and with it the energy and the share of the duty-cycle allowance it consumes34. The bars are computed with the modem’s published formula for a 20-byte payload. Figure as text: Time on air by spreading factor, 20 bytes at 125 kHz A bar chart of LoRa time on air for spreading factors 7 to 12, from about 57 ms to about 1.3 s. | Spreading factor | Time on air | | --- | --- | | SF7 | 56.6 | | SF8 | 102.9 | | SF9 | 185.3 | | SF10 | 370.7 | | SF11 | 741.4 | | SF12 | 1,318.9 | **02** Simulator ## What the duty cycle allows. Set the spreading factor, the payload and the duty-cycle limit, and read how many uplinks an hour a device may send. The same arithmetic decides whether a network can add a thousand more sensors. Figure as text: Uplinks per hour within a duty-cycle limit A bar chart of time on air for spreading factors 7 to 12 with the chosen factor in red. | Spreading factor | 10 SF | | --- | --- | | Payload | 24 bytes | | Duty-cycle limit | 1 % | | Time on air (125 kHz, CR 4/5) | 370.7 ms | | Uplinks per hour within the limit | 97 | | Shortest interval between uplinks | 37 s | **03** Systems diagram ## A mesh that heals. In a mesh, each node can forward for its neighbours toward a border router, using a routing protocol designed for lossy, low-power links5. Fail a node and watch the routes find another way, or not. Figure as text: A low-power mesh with two border routers A four-tier diagram of leaf sensors, forwarding nodes, border routers and the edge, with red routes from every leaf. - **Leaf sensors** : A, B, C, D, E - **Forwarders** : Node 1, Node 2, Node 3 - **Border routers** : Border 1, Border 2 - **Edge** : Edge 14 links. Scenarios: All nodes up; Node 2 fails; Border 1 fails; Nodes 1 and 3 fail. **04** Timeline to 2030 ## A family of low-power standards. Cellular low-power access arrived with NB-IoT and LTE-M in Release 136; sub-gigahertz Wi-Fi extended range for sensors7; the long-range protocol many networks use became an ITU-T recommendation in 20211. Release 17 added satellite access for IoT devices8. Figure as text: Low-power wide-area and mesh standards A timeline from 2012 to 2030 with RPL, NB-IoT and LTE-M, 802.11ah, ITU-T Y.4480, IEEE 802.15.4-2020 and IoT over satellite. 1. **2012-03** RPL routing for lossy networks (RFC 6550). IPv6 routing for low-power meshes. 5 2. **2016** Sub-gigahertz Wi-Fi (IEEE 802.11ah). Long-range, low-power Wi-Fi for sensors. 7 3. **2016-06** NB-IoT and LTE-M. Low-power cellular access in Release 13. 6 4. **2020** Low-rate wireless networks revised (IEEE 802.15.4-2020). The radio beneath many mesh protocols. 2 5. **2021-12** Long-range LPWAN protocol recommended (ITU-T Y.4480). Adopted as an ITU-T recommendation. 1 6. **2022-06** IoT over satellite. Release 17 adds non-terrestrial access for NB-IoT and LTE-M. 8 Time on air, 20-byte payload ms 0 500 1,000 1,500 2,000 SF7 56.6 SF8 102.9 SF9 185.3 SF10 370.7 SF11 741.4 SF12 1,318.9 Figure 1 Data story Figure 1. Time on air by spreading factor, 20 bytes at 125 kHz. A bar chart of LoRa time on air for spreading factors 7 to 12, from about 57 ms to about 1.3 s. ## References 1. [Recommendation ITU-T Y.4480: Low power protocol for wide area wireless networks](https://www.itu.int/rec/T-REC-Y.4480) . International Telecommunication Union, Telecommunication Standardization Sector, 2021. 2. IEEE 802.15.4-2020: Standard for low-rate wireless networks. IEEE Standards Association, 2020. 3. SX1276/77/78/79 datasheet, section 4.1.1.7: LoRa time on air. Semtech, 2020. 4. ETSI EN 300 220-2: Short range devices operating in 25 MHz to 1 000 MHz (duty-cycle limits). European Telecommunications Standards Institute, 2018. 5. [RFC 6550: RPL, IPv6 routing protocol for low-power and lossy networks](https://www.rfc-editor.org/rfc/rfc6550) . Internet Engineering Task Force, 2012. 6. [3GPP Release 13: NB-IoT and LTE-M](https://www.3gpp.org/specifications-technologies/releases/release-13) . 3rd Generation Partnership Project, 2016. 7. IEEE 802.11ah: sub-1 GHz Wi-Fi (HaLow), incorporated in IEEE 802.11-2020. IEEE Standards Association, 2016. 8. [Releases: the timeline of 3GPP Releases 17 to 21](https://www.3gpp.org/specifications-technologies/releases) . 3rd Generation Partnership Project, 2025. ## Related stories [Place: Farmland **Field to forecast** A farm observes water: in the soil, in the crop and in the air above it. Crop water use is computed from weather with a method agronomists have shared for…](https://observatory.global/stories/farmland/) [System: End to end **An observation grid, end to end** An observation is not a reading. It is a reading with a place, a time, a calibration and a path that anyone can follow back. An observing grid is the…](https://observatory.global/stories/observation-grid/) [System: Satellite backhaul **When the backhaul is a satellite** For a remote site, the satellite is not a backup; it is the network. Since Release 17, the cellular standard includes satellites as part of the radio access…](https://observatory.global/stories/ntn-backhaul/) ## Where this applies [Connectivity](https://observatory.global/connectivity/)[Sensors & instruments](https://observatory.global/sensors/)[Hardware & power](https://observatory.global/hardware/)[Agriculture](https://observatory.global/industries/agriculture/)[Water](https://observatory.global/industries/water/)[Cities](https://observatory.global/industries/cities/)[Nature](https://observatory.global/industries/nature/)[Field tour: farm](https://observatory.global/environments/farm/)[Field tour: city block](https://observatory.global/environments/city-block/) © 2026 Nexus Observatory Inc. **Legal** [Privacy notice](https://observatory.global/legal/privacy/) · [Terms of use](https://observatory.global/legal/terms/) · [Cookie policy](https://observatory.global/legal/cookies/) · [Accessibility](https://observatory.global/legal/accessibility/) · [Official languages](https://observatory.global/official-languages/) · [Notices](https://observatory.global/notices/) **Company** [About](https://observatory.global/about/) · [Open governance](https://observatory.global/consortium/) · [Contact](https://observatory.global/contact/)