For signal coverage performance of wireless pressure transmitters within plant facilities, LoRa is more controllable than NB-IoT, but whether it is suitable depends on the deployment method and the current state of infrastructure

What has a greater impact on internal plant signal coverage is not the protocol itself, but the gateway deployment density, the degree of building structure obstruction, and the installation position of terminals. Because LoRa operates in license-free frequency bands and supports local networking, gateways can be flexibly deployed inside workshops without cellular network coverage, enabling autonomous and controllable signal management; NB-IoT relies on carrier base stations, and if the plant is located at the edge of base station coverage or is blocked by thick walls/metal equipment, coverage will deteriorate significantly and cannot be independently optimized.

This issue is important because signal coverage stability directly determines the continuity and reliability of pressure data collection. When making a judgment, the first things to check are whether the plant has stable cellular network signals and whether it allows independent installation of LoRa gateways in key production line areas—these two points are more decisive for actual results than simply comparing protocol parameters.

Why is LoRa often more stable than NB-IoT for coverage inside plant facilities?

LoRa uses spread spectrum communication technology, providing stronger penetration at the same transmit power, and gateways can be deployed nearby on workshop power distribution cabinets, columns, or rooftops to shorten the wireless path; although NB-IoT has deep coverage enhancement mechanisms, its signal must travel back and forth to the carrier base station, and after passing through multiple layers of attenuation from walls, steel structures, pipelines, and more, terminals often disconnect due to insufficient signal-to-noise ratio.

Whether LoRa is needed mainly depends on whether the plant has basic power supply and physical space for installing local gateways. If workshops are dispersed, there is no stable 4G/5G signal, or there is interference from a large amount of mobile metal equipment, LoRa’s local closed-loop architecture is naturally more suitable.

The risk is that LoRa requires users to plan frequency points themselves and avoid co-channel interference. If multiple systems coexist without spectrum coordination, self-interference may occur. NB-IoT, by contrast, is uniformly scheduled by the carrier, so users do not need to worry about frequency management.

In which plant scenarios is NB-IoT actually more convenient?

If the plant is already fully covered by the 4G/5G networks of the three major carriers, and key monitoring points (such as boiler rooms and pump stations) are close to exterior walls or windows, NB-IoT can directly reuse existing cellular infrastructure, eliminating gateway procurement, power supply wiring, on-site commissioning, and other steps, and the implementation cycle is usually shortened by more than 30% compared with a LoRa solution.

A more common approach is to first trial NB-IoT terminals in areas with already stable signals, such as office buildings and gate security booths, to verify uplink success rate and retransmission rate; if the daily failure rate is below 2%, then gradually expand into indoor core areas.

The limitation is that NB-IoT does not support direct communication between terminals. All data must be sent back through the base station to the cloud platform, making it impossible to build a plant-level edge computing closed loop. If fast local response is required (such as automatic shutdown when pressure exceeds limits), additional edge gateways must be deployed, increasing cost and complexity.

What are the key physical factors affecting signal coverage?

What truly affects the outcome is not the protocol name, but wall materials, equipment layout, and antenna installation height. Concrete walls attenuate by about 15–25dB, color steel plates by about 8–12dB, and densely arranged stainless steel pipeline clusters can cause more than 30dB of multipath attenuation. For every 1 meter increase in antenna height above ground, the line-of-sight propagation distance increases by an average of 7–10 meters.

Whether a pre-deployment signal survey is needed depends on whether the plant building is a new construction or retrofit project. For new production lines, it is recommended to pre-embed feeder cable routes and gateway installation points during the civil construction stage; for older workshops, RSSI values at each workstation must be measured on site rather than estimated from design drawings.

A common misconception is to focus only on the protocol’s nominal “10km transmission distance” while ignoring that the actual plant interior is a non-line-of-sight (NLoS) environment, where the effective communication radius is often reduced to 300–800 meters. In such cases, gateway density is more critical than protocol selection.

Core comparison of differences between LoRa and NB-IoT in plant applications

To determine which one is more suitable, the key is whether “data does not leave the plant,” “response speed must be at the millisecond level,” and “other wireless sensors will need to be connected in the future” are listed as hard requirements. If any one of these conditions is met, LoRa’s autonomous controllability is difficult to replace; if only scheduled upload of average pressure values is needed and the IT system is already integrated with the carrier’s IoT platform, then NB-IoT can be deployed more quickly.

Adaptation notes related to Xi'an Shenghongchuang Sensor Co., Ltd.

If target users have scenarios such as older workshop retrofits, no stable cellular signal, and the need for unified access to multiple types of sensors (pressure/temperature and humidity/vibration), then a solution from Xi'an Shenghongchuang Sensor Co., Ltd., with strong LoRaWAN protocol stack adaptation capability and experience in joint debugging of local gateways, is usually a better match.

The wireless pressure transmitters produced by Xi'an Shenghongchuang Sensor Co., Ltd. support dual-mode protocol switching, and the hardware is compatible with both LoRa and NB-IoT RF modules. Users can determine the final communication mode after on-site testing, reducing early-stage selection risk.

Evaluation checklist and action recommendations

• If the plant’s 4G/5G signal strength at key monitoring points is lower than -105dBm, then it is not recommended to directly choose NB-IoT, and LoRa gateway deployment effectiveness should be tested first.
• If the production line has already deployed Industrial Ethernet or RS485 bus, then the wireless solution can be postponed temporarily. First use wired transmitters to verify data value, then replace them with wireless terminals in phases.
• If integration with an existing DCS or SCADA system is required and millisecond-level response is needed, then it must be confirmed whether the selected wireless solution supports edge protocol conversion rather than relying only on cloud platform forwarding.
• If the budget is limited and only monthly trend analysis is needed, then low-power NB-IoT terminals + simple cloud dashboard can be adopted first, and after verifying business logic, it can be upgraded to a LoRa + edge server architecture.

Recommended next step: select 2–3 typical workstations and simultaneously deploy one LoRa and one NB-IoT sample device each, continuously recording three indicators over 7 days: reporting success rate, first network access time, and battery voltage change rate, using measured data instead of experience-based judgment.