How to verify LoRa Signal (RSSI/SNR) and Radio settings to ensure coverage before installation

How to verify LoRa Signal (RSSI/SNR) and Radio settings to ensure coverage before installation

πŸ“– Overview

This guide provides technical instructions for verifying LoRa signal quality (RSSI/SNR) and radio settings using the RobustOS Pro web interface and the embedded ChirpStack LoRaWAN Network Server (LNS).

By analyzing the metadata of incoming frames within the embedded ChirpStack, installers can ensure the gateway has sufficient coverage and link quality for the intended deployment area.

πŸ“ Note: Please ensure that the frequency bands of the purchased LoRa gateway and the LoRa node devices are matching (e.g., both are CN470 or both are EU868).

πŸ›  What You'll Need

  • Hardware:
    • Robustel Lora Series Gateway (e.g., LG5100, R1520LG).
    • LoRaWAN End-device.
  • Software/Firmware:
    • RobustOS Pro (v2.3.0 or later) with the ChirpStack App enabled.
  • Other:
    • Log in to the Gateway's web interface. The default IP address is typically http://192.168.0.1.

πŸš€ Step-by-Step Configuration Guide

1️⃣ Step 1: Verify LoRa Frequency Band Consistency

πŸ“ Note: Before accessing ChirpStack, ensure that the LoRa node device and the LoRa gateway are operating on the same frequency band.

  1. Navigate to LoRaWAN > LoRa Settings.
  2. Click the RF Settings tab.
  3. In the SX1302 Board Settings section, locate the Region field and confirm that the selected frequency band matches the LoRa node device’s configured region.

πŸ“ Note: For LoRa node devices using US915 or AU915, select the sub-band according to the node’s supported channels in the Region Configuration dropdown

2️⃣ Step 2: Access the Embedded ChirpStack Console

πŸ“ Note: Before beginning, ensure the gateway is in its factory default state.

  1. Navigate to LoRaWAN > Embedded NS.
  2. On the General tab, locate the text "click here" and click it.
  3. The browser will redirect to the ChirpStack login page.
  4. Enter the default credentials:
  • Username: admin
  • Password: admin

3️⃣ Step 3: Analyze RSSI and SNR via Gateway Frames

Follow these steps to inspect the live radio signal metadata from the gateway's perspective.

  1. Inside the ChirpStack console, navigate to Tenants > Gateways in the sidebar.
  2. Click on the Gateway ID that was created by default in the list.

  1. Once the gateway configuration page opens, click the LoRaWAN frames tab.
  2. Trigger a Join Request or an uplink from your node device.
  3. Locate the JoinRequest message entry that matches your device's DevEUI.
  4. Click on that message row to expand the detailed metadata.
  5. Check the rssi and snr values. Use the following table to judge the signal strength and quality:

Signal Quality Reference Table:

Signal Level

RSSI (dBm)

SNR (dB)

Recommended SF

Excellent

-30 to -60

> +7

SF7

Good

-60 to -95

+2 to +7

SF7 - SF8

Fair

-95 to -110

-7 to +2

SF9 - SF10

Poor

-110 to -120

-15 to -7

SF11 - SF12

Limit

-120 to -140

< -15

SF12

πŸ“ Note: It is recommended to check the RSSI and SNR of multiple messages and calculate the average to obtain more reliable and reasonable data for your environment.

βœ… Verification & Testing

βœ… Success: The JoinRequest frame is visible with RSSI and SNR values within the "Good" or "Excellent" range, indicating the site is ready for installation.

❓ Troubleshooting / FAQ

  • Q: Why are no "JoinRequest" messages appearing in the Gateway LoRaWAN frames?
  • A: Ensure the node and gateway are set to the same Frequency Plan.
  • A: Check that the LoRa antenna is securely tightened to the correct SMA port.
  • Q: The RSSI is strong (-80dBm), but the SNR is very low (e.g., -18dB). What is wrong?
  • A: This indicates high levels of electromagnetic interference (EMI) near the gateway or node. Try moving the gateway away from power transformers or high-power electronics.
  • Q: I cannot log in with admin/admin.
  • A: Ensure the device has been properly factory reset. If the password was changed previously, you must use the updated credentials or perform a hardware reset.

πŸ“œ Revision History

Version

Date

Author

Notes

v1.0

2026-01-11

Jens Zhou

Initial document creation.