LPWAN on an operator network, for scattered devices
The SimtoLink NB-IoT gateway is built on 3GPP LTE Cat-NB1 (NB-IoT, narrowband IoT). It uses the licensed spectrum of China Mobile, China Unicom, and China Telecom. Wired devices on Modbus and other serial ports send their data to the cloud over the operator network. It fits scattered, low-power LPWAN sites such as water meters, gas meters, manhole covers, and fire protection, and there is no private network to build.
The design is low power, with eDRX (extended discontinuous reception) and PSM (power saving mode). A solar-and-battery build can run where there is no mains. The SimtoLink NB-IoT offering is already in smart-water, smart-fire, and smart-manhole projects, with more than 200,000 devices connected.
Specifications and protocols
The SimtoLink NB-IoT gateway is offered in several builds by band, downlink interface, and supply, for LPWAN access on scattered sites. Typical figures:
| Item | Typical specification | Notes |
|---|---|---|
| Communications | NB-IoT B8/B5 | China Mobile / China Unicom / China Telecom |
| Downlink | RS485/RS232/Modbus | 1～32 slaves |
| Uplink protocol | CoAP, MQTT, HTTP | APN configurable |
| Supply and enclosure | DC 12V / solar + battery | IP65, -40～85℃ |
Power is <1W. A SIM slot takes a card or an eSIM. Remote configuration and OTA are included. Figures can differ by model; the product specification governs.
Typical applications and results
From water utilities to fire protection and city works, the gateway covers wireless access for scattered devices. Typical jobs and what they changed:
Remote water meters
A water utility fitted NB collectors on 50,000 remote meters. Readings go straight to the meter-reading platform over the operator network, with no concentrator to install, so the deployment costs less.
Wireless smoke detectors
A fire-protection company put NB smoke detectors in older buildings. Alarms join the network without new cable, which suits a retrofit.
Manhole-cover monitoring
A city fitted NB tilt sensors on 20,000 manhole covers. An abnormal opening raises an alarm, for people and vehicles on the street.
Gas-meter reading
A gas company fitted NB collectors in scattered residential areas. Remote reads and leak alarms travel on the operator network.
Selection and deployment
- Coverage: Confirm local NB coverage before you install. When you order, confirm the operator, the plan, and the APN (access point name). SimtoLink can supply NB SIMs and data plans.
- Device setup: When several meters share a bus, assign Modbus addresses so they do not collide. Where there is no mains, choose the solar-and-battery build.
- Latency and bandwidth: If the job needs low latency, look hard at NB, or use 4G Cat.1. NB fits small payloads and infrequent reports.
- Operations: Check online rate and data use on a schedule. Renew the NB plan before it lapses. Without mains, watch the solar panel and the battery. SimtoLink provides usage monitoring and plan management.
- How to start: Before a large rollout, run a small pilot and check coverage and power draw.
Rollout and day-to-day care
A practical sequence for putting an NB-IoT gateway into service:
SimtoLink can test coverage and stay on for operations, so online rate and reporting stay steady.
Services and support
SimtoLink supplies the NB-IoT scheme and the data plan, helps with selection and platform connection, and can test coverage and support operations. A product manual and a proposal are available.