Live Signal Monitoring & Multi-APN

The Live Signal Dashboard is QManager's primary operational display. It streams high-resolution baseband telemetry directly from the Quectel radio without lagging the web browser.

QManager RM551E Dashboard screen — RM551E: The dashboard shows network status, primary LTE and 5G signal, and device information at a glance.

Overview of Cellular Metrics#

Metric	Full Name	Ideal Range	Acceptable Range	Poor Range	Notes
RSRP	Reference Signal Received Power	> -80 dBm	-80 to -100 dBm	< -105 dBm	The true signal strength of the serving cell.
RSRQ	Reference Signal Received Quality	> -10 dB	-10 to -15 dB	< -16 dB	Signal quality factoring in interference and channel load.
SINR	Signal-to-Interference-plus-Noise	> 20 dB	10 to 20 dB	< 5 dB	Best predictor of download and upload throughput.
RSSI	Received Signal Strength Indicator	> -65 dBm	-65 to -85 dBm	< -90 dBm	Wideband power including serving, neighbor, and noise.

4x4 MIMO Per-Antenna Breakdown#

Quectel 5G modules (RM520N and RM551E) utilize 4 distinct antenna ports (ANT0, ANT1, ANT2, ANT3). Traditional router GUIs average these values into a single misleading number.

QManager displays the individual signal strength and quality for all four antenna lines:

ANT0 (PRX): Primary Receiver
ANT1 (DRX): Diversity Receiver
ANT2 (MIMO1): Spatial Stream 1
ANT3 (MIMO2): Spatial Stream 2

Live Telemetry Engine Architecture#

Rather than executing slow AT commands on every browser poll, QManager's backend features a dedicated tmpfs circular buffer:

The background daemon reads cellular metrics every 1,000ms.
Formats readings into a compact JSON slice in /tmp/qmlive/signal.json.
The web frontend fetches this static file via HTTP ETag cache headers.
If the modem enters high-load state, the adaptive engine backs off automatically to prevent AT command collisions.

Multi-APN Real-Time Monitoring#

For corporate and IoT setups with dual PDP contexts (e.g. APN 1 for public internet and APN 2 for private corporate intranet or IMS VoLTE):

Real-time IP address and DNS readout for each active context.
Individual traffic byte counters (TX/RX) per APN.

Screens in QManager#

QManager RM551E Dashboard (full page) screen — RM551E: The full dashboard, including carrier aggregation, device health, connection quality, recent activity and signal history.

QManager RM520N Dashboard (full page) screen — RM520N: The whole dashboard, including connection quality, signal history, and recent activity.

QManager RM551E Speed test screen — RM551E: Run a speed test from the dashboard to see download, upload, ping and jitter.

QManager RM520N Speed test screen — RM520N: The speed test dialog shows download, upload, and ping from the modem itself.

QManager RM551E Antenna statistics screen — RM551E: Per-antenna RSRP, RSRQ and SINR for each LTE and 5G receive chain.

QManager RM520N Antenna statistics screen — RM520N: Antenna Statistics compares RSRP, RSRQ, and SINR on all four receive chains.

QManager RM520N Dashboard screen — RM520N: The dashboard gives a live view of network status, signal, and device details.