LoRaWAN vs NB-IoT vs Sigfox: which LPWAN fits your 2026 project?

The sharpest distinction between LoRaWAN and NB-IoT is not radio performance — it is who owns and operates the network.

LoRaWAN's ISM-band operation means any organisation can deploy gateways without a spectrum licence or carrier agreement. A standard 8-channel LoRaWAN gateway (Kerlink Wirnet iFemtoCell, RAK Wireless WisGate Edge, Dragino DLOS8) costs £150-$500, covers several square kilometres outdoors or several floors indoors, and connects to a Network Server you control — ChirpStack (open source, self-hosted) or The Things Industries (managed SaaS). This architecture gives the project team complete data sovereignty: every uplink flows through infrastructure you operate. For a smart-building integrator deploying LoRaWAN sensors across a commercial estate, this is a strong argument — no carrier contract, no per-device SIM, no dependency on a third party's coverage map.

NB-IoT terminals attach only to licensed eNodeB infrastructure operated by carriers. In the UK that means BT/EE, Vodafone and Three; in the US, T-Mobile, AT&T and Verizon; in Australia, Telstra and Optus. The carrier handles network management, coverage guarantees and SLAs. For a utility deploying 500 000 electricity meters across a national territory, that is the right trade-off — the project does not need to build or maintain radio infrastructure, and the carrier SLA covers coverage gaps. But for a property manager instrumenting a single office campus, a carrier subscription per device adds operational cost and a third-party dependency that a private LoRaWAN gateway eliminates.

For smart-building and BMS integrations — the CertifBus core audience — LoRaWAN consistently wins. Sensors connect to an on-site gateway; data flows via MQTT to a building management platform (Schneider EBO, Siemens Desigo CC, Tridium Niagara); no carrier involvement. NB-IoT is relevant when the building is large, geographically dispersed, or when the client insists on carrier-SLA coverage rather than managing a private gateway fleet.

Both technologies are designed for ten-year battery life — the engineering paths diverge.

LoRaWAN Class A is the simplest energy profile in LPWAN. The radio is fully off between uplinks. A Semtech SX1262 in deep sleep draws ~1.5 µA. The only energy expenditure is the TX burst (20-130 mA, 50-1 500 ms depending on SF) plus the two short RX windows that follow. At an hourly uplink cadence with SF9 in EU868, a device on two AA Li-SOCl2 cells (2 400 mAh each = 4 800 mAh total) conservatively delivers 10-14 years. Vendor datasheets bear this out: Diehl Metering Hydrus cites 12 years, Itron Cyble cites 10 years, Sagemcom Siconia cites 15 years at daily cadences. The profile is predictable and vendor-independent — any Class A implementation on any network delivers the same energy envelope.

NB-IoT PSM works differently. The device registers with the carrier network, sends its data, then requests a PSM timer via AT+CPSMS (3GPP TS 27.007). The network grants a T3412 value — often 1 to 24 hours — during which the device is unreachable but draws ~3-10 µA in deep sleep (some modules, like Quectel BC660K-GL, achieve ~2 µA). PSM suits use cases where messages are infrequent but must carry larger payloads: a monthly meter report with 20 index values, an alarm with a 500-byte event log, or a firmware delta-patch. The 1 600-byte payload limit means NB-IoT can send meaningful data in a single message where LoRaWAN SF12 would need fragmentation across several 51-byte frames.

eDRX (Extended Discontinuous Reception) is the complementary NB-IoT mode for devices that need faster downlink response without fully waking: the device stays registered but only checks the paging channel every few minutes or hours rather than every 1.28 seconds (LTE default). Combined with PSM, a smart-meter can spend most of its life in PSM and shift to eDRX for configuration windows.

Sigfox achieves similar battery life through extreme protocol simplicity: one 12-byte UNB message costs ~20 mA for ~2-6 ms. With 140 messages per day at that budget, a D-cell battery lasts many years. The constraint is not energy — it is the 12-byte ceiling and the one-way nature of the network in practice.

Coverage depth is often the deciding factor when comparing LoRaWAN and NB-IoT for utility metering.

The key metric is MCL (Maximum Coupling Loss) — the maximum signal attenuation the link can survive end-to-end. NB-IoT targets 164 dB MCL (the 3GPP Release 13 design goal), compared to roughly 157 dB for LoRaWAN at SF12 in EU868. That 7 dB difference translates to an ability to reach devices in deeper basements, metal enclosures and thick-concrete buildings that occasionally lose LoRaWAN connectivity.

NB-IoT achieves this through HARQ repetitions: a device can retransmit the same subframe up to 128 times (Release 14 adds even more). The network coherently combines energy across repetitions, effectively trading latency for coverage. For a gas meter bolted inside a metal utility cabinet in a basement, that repetition budget matters.

LoRaWAN's answer is density: deploying an additional indoor gateway. A £200 LoRaWAN indoor concentrator hung in a building's utility room turns a marginal link into a strong one. For a landlord with 200 apartments in the same block, one indoor gateway adds coverage without any carrier negotiation.

In smart-electricity-metering, NB-IoT holds the high ground. Enedis's next-generation Linky meter program (Linky NG, target 2027-2030 rollout) is planned around NB-IoT with Orange, leveraging operator-grade MCL and national coverage without private gateway infrastructure. For gas and water in UK and Australian deployments, LoRaWAN with indoor gateways dominates new tenders — Arqiva Smart Metering (UK), Telstra IoT (AU) and most municipal water deployments use LoRaWAN.

Sigfox deserves an honest assessment rather than a dismissal. It was genuinely pioneering: the first LPWAN to achieve national coverage (France, 2013), the first to prove that a 12-byte message from a sensor buried in a field could reach a cloud endpoint reliably. The technology — UNB (Ultra-Narrow Band) at 100 Hz channel spacing — is elegant: simple, power-efficient, and excellent at avoiding interference.

The business case collapsed for reasons that had little to do with the radio. Sigfox's proprietary network required capital-intensive deployment in each country and generated device-subscription revenue only; the IoT market scaled more slowly than projected, and LoRaWAN's open ecosystem took volume. Sigfox filed for insolvency in January 2022. UnaBiz, a Singapore-headquartered LPWAN operator, acquired the assets in April 2022 and has maintained the network since.

In 2026 the Sigfox network is live in France and approximately 70 countries. UnaBiz has announced a 0G branding strategy and is building NB-IoT / LoRaWAN bridges. However, the protocol ceiling of 12 bytes uplink and 140 messages per day is not a carrier decision — it is baked into the radio standard. You cannot FUOTA a Sigfox device. You cannot send a 100-byte configuration payload. You cannot reliably trigger an actuator (4-byte downlink, maximum 4 per day).

Practical guidance: If you have an existing Sigfox fleet under contract with UnaBiz and your application genuinely fits within 12 bytes and a few messages per day, renewing is defensible. For greenfield deployments starting in 2026, Sigfox is not the right starting point — LoRaWAN and NB-IoT offer better protocol flexibility and clearer long-term ecosystem support.

CertifBus covers the building automation and industrial IoT protocols that real professionals get certified on. LoRaWAN sits at the intersection of these worlds as the dominant wireless sensing layer in smart-building deployments.

A typical modern commercial building instruments at two levels. At the control layer: KNX or BACnet/MSTP for wired actuators — lighting, blinds, HVAC zone valves, access control. At the sensing layer: LoRaWAN for wireless sensors — room temperature/humidity/CO₂ (Elsys ERS-CO2, Milesight EM300-MCS, Adeunis Comfort), desk occupancy, sub-metering of electricity, heat and water. The two layers are bridged at the building controller (Schneider EcoStruxure Building Operation, Siemens Desigo CC, Tridium Niagara N4) via MQTT or a protocol gateway. KNX handles the deterministic real-time actuation; LoRaWAN handles the distributed, battery-powered sensing.

NB-IoT is a poor fit for in-building sensor networks: it requires a carrier SIM per device (cost and complexity), does not support private gateways (coverage inside a building depends entirely on carrier signal through walls), and adds carrier contract management to a building operator's IT stack. Inside a 50 000 m² office campus, a private LoRaWAN gateway deployed per floor outperforms any carrier-NB-IoT coverage at a fraction of the total cost.

The LoRaWAN Airtime Calculator (available free on CertifBus) helps system designers verify that their payload sizes and transmit intervals respect EU868 duty-cycle rules before deployment — a practical tool for smart-building IoT specification.