Definition and Positioning
LoRa (Long Range) is a long-distance, low-power wireless technology based on spread spectrum modulation, introduced by Semtech, operating in unlicensed bands (China 470MHz, Europe 868MHz, North America 915MHz, etc.). The typical transmission distance can reach over 15 km in suburban areas and 2–5 km in urban areas, with battery life of several years. LoRaWAN is the networking protocol of LoRa, defining network architecture, device activation, security mechanisms, etc., and, like NB-IoT, is a mainstream LPWAN (Low-Power Wide-Area Network) technology.
Differences from NB-IoT
| Features | LoRa/LoRaWAN | NB-IoT |
|---|---|---|
| Frequency band | Unlicensed (ISM) | Licensed (operator) |
| Deployment | Self-built gateway | Operator networks |
| Coverage | Long-distance, low density | Deep coverage, high density |
| Cost | No monthly fee, self-built cost | Data charges, operator management |
| Applicable to | Private network, campus | Public network, nationwide roaming |
Technical Features
Long distance
Suburbs 15km+, city 2–5km, suitable for low-density wide coverage
Low power consumption
Battery-powered for several years, suitable for outdoor, agricultural, and other scenarios
Unlicensed frequency band
No spectrum application required, flexible deployment
Low cost
Low module cost, no monthly operator fee
Typical Applications
Low-speed, wide-coverage, long battery life scenarios such as smart metering, agricultural monitoring, smart cities, asset tracking, and environmental monitoring. Suitable for self-built network needs in parks, farms, mines, etc.
SimtoLink focuses on cellular IoT SIM cards as its core business, with LoRa serving as a non-cellular LPWAN, complementing NB-IoT. In scenarios where customers need to build private networks, have no carrier coverage, or are cost-sensitive (such as farms, mines, or overseas projects), LoRa is an optional solution; whereas for scenarios requiring nationwide coverage, roaming, or carrier-level guarantees, NB-IoT or Cat.1 is recommended. SimtoLink provides customers with multi-standard comparisons and selection recommendations during solution selection, helping them choose the most suitable communication method based on the scenario; for hybrid networking (LoRa + cellular gateway) scenarios, SimtoLink's IoT SIM cards can provide reliable backhaul for the gateway.
What the Spreading Factor Buys Is Airtime
The core of LoRa is chirp spread spectrum. One symbol sweeps across a bandwidth, and each step up in spreading factor doubles the symbol length. The same bits take longer on the air in exchange for more processing gain. “Longer range” is not free coverage. It is bought with a lower bit rate and a longer hold on the channel. Bandwidth, coding rate, and preamble length all move the link budget. Change only the spreading factor and the lab result will not match the field.
This is physical-layer modulation. It does not say who may join, how keys are derived, or when a downlink window opens. Those belong to LoRaWAN or to a private networking protocol. Two modules that can hear each other only show that frequency, bandwidth, and spreading factor match. They do not show that the site already has a network server, duplicate elimination, or roaming across gateways.
What an Unlicensed Band Requires
China commonly uses the civil metering band near 470 MHz. Europe’s 868 MHz and North America’s 915 MHz split channels and limit transmit power differently. The region profile in the module firmware has to match the antenna, the certification, and the local radio rules. European firmware cannot simply be soldered onto a domestic frequency. Unlicensed does not mean there is no power-spectral-density or duty-cycle limit. A long continuous transmission can break local rules and can also saturate the gateway receiver.
The fit is a small payload, sparse reports, and a fixed site where a gateway can be built or rented: soil moisture in a field, or meters on a campus. When the service needs nationwide public roaming, mobility handover, or an IP session, a spread-spectrum link does not replace cellular. If the gateway backhaul is cellular and that backhaul drops, the nodes keep transmitting. Data sits in the gateway or is simply lost. The application has to accept a window in which the air interface succeeded and the platform has nothing. For how licensed and unlicensed spectrum are divided, see spectrum management. Do not occupy an ISM channel with the habits of a cellular carrier.
Open-Air Distance Is Not the Design Coverage
A common error is to place gateways from the suburban distance in a vendor brochure. In a city, building diffraction, metal-roof reflection, and same-channel collisions shrink the usable distance. Raising the spreading factor to the maximum only partly compensates, and it stretches a single packet into seconds, so collisions become more likely. Another error is to pin every node at the highest spreading factor. Nearby nodes could have used a short symbol. Instead they hold the channel, and distant nodes have a harder time getting in.
Antenna installation is often skipped. A ceiling antenna stuck inside a metal box, feeder loss larger than the link margin, or a gateway and a node on different polarizations all look like “the distance is short, yet packets are lost.” Sweep and send test packets at the real mounting height first. Record spreading factor, received SNR, and airtime, then decide density. Blaming every loss on “LoRa is unstable” misses two real causes: a used-up duty cycle, and a gateway channel plan that is too thin.
Put feeder, connector, and surge-protector loss into the link budget. Do not stop at the antenna’s rated gain. After a gateway is moved to the roof, a longer feeder than in the trial can wipe out the extra height. At the receiver, look at the noise floor too. Other transmitters on the same site, switching supplies, and variable-frequency drives raise the floor, spread-spectrum gain is eaten by noise, and the distance formula no longer holds. The node’s transmit current pulse is very narrow. If the supply impedance is high, the voltage sags, radiated power falls below the setting, and the symptom is occasional loss far away with everything fine nearby. A node mounted inside a metal box has its antenna pattern reshaped by the box. The rated distance cannot be used as is.