Signal, trend and reachability

Score

Every reading becomes a score from 0 to 100, so Zigbee, Thread and Wi-Fi fit on one scale:

Network	Score	Chart shows
Zigbee	LQI / 255 × 100	LQI 0–255
Thread	RSSI from −100 dBm (0) to −50 dBm (100), capped by the link quality: LQI 3 → 100, 2 → 59, 1 → 24, 0 → 0	RSSI in dBm
Wi-Fi (Matter)	RSSI from −90 dBm (0) to −50 dBm (100)	RSSI in dBm

The score drives the traffic light, the heatmap and the events; the charts keep the network's own value. LQI values of different Zigbee chips are not strictly comparable; the history of one device says more than the comparison of two.

Traffic light

	Score of the last 60 minutes (median)
Good	60 and more
Fair	25 to 59
Weak	below 25
Offline	not reachable (below)
Unknown	no reading yet

Without a reading in the last hour the latest hourly median counts. Both thresholds can be changed under Settings.

Trend

A linear regression over the hourly medians of the last 72 hours, read as the change it predicts over those 72 hours: more than 15 points down is falling, more than 15 up rising. It needs at least 24 hourly values; a single bad reading does not move it. Each hour of the day first loses its own mean over the window, so a daily rhythm (a socket that is weak every evening) is no trend and the verdict does not change with the time of day; a change from day to day still counts.

Reachability

A device is offline when

• Zigbee2MQTT or matterjs-server reports it offline (availability, or a Matter node the server cannot reach), or
• it has been silent for three times its usual interval between messages, at least 30 minutes. The usual interval is the gap a moment of the last 7 days typically falls into (the median of the gaps, weighted by their length), so a remote that sends bursts of presses seconds apart keeps the long pauses between them as its interval.

A device without a known interval is judged by the report only. Coordinators, border routers and access points are never marked offline from silence; their state comes from the bridge.

Recurring patterns

Once a day (3 a.m.) Funkloch looks at the last 7 days by hour. A device that is weak at the same hours on at least 5 of 7 days (a window of at most 12 hours), and rarely weak outside it, gets a recurring pattern: typically Wi-Fi load in the evening or a device that runs at that time.

Transmit errors (Thread routers)

With every reading (every 5 minutes) Funkloch asks each Thread router for its MAC counters (macCounters in the network diagnostics). They count up from the router's start, so Funkloch works with the difference between two readings; a counter lower than before means the router restarted, and the new value counts from zero. The transmit error rate is

ΔifOutErrors / (ΔifOutUcastPkts + ΔifOutBroadcastPkts)

OpenThread fills ifOutErrors with the failed clear channel assessments (mTxErrCca in openthread src/core/thread/net_diag_tlvs.cpp): the router wanted to send and found the channel busy. The packet counters count each frame once, however often it was retried (include/openthread/link.h). The rate therefore says how often the router cannot get on air: Wi-Fi or another transmitter close to it, or a radio that hears the channel as busy. Its RSSI does not show this: a router can be heard well and still fail to send.

The router's page shows the rate of the last 24 hours and one bar per hour over 7 days (an hour with fewer than 20 frames has none). From 5 % over 24 hours the rate is marked and becomes the event many transmit errors; below 3 % it is back to normal. Fewer than 200 frames in 24 hours give no rate.

Why 5 %: routers on a quiet channel stay far below 1 % (on the network that led to this check, the other routers below 0.1 %, an ESP32-C6 router in the cellar at about 10 %). 5 % is fifty times the normal case and means one frame in twenty met a busy channel, while an hour of Wi-Fi load or a microwave does not reach it over 24 hours.

Storage

Data	Kept
every reading, the transmit counters	14 days (2–90)
hourly median, min, max, message count, minutes offline	365 days (30–3650)
network maps	as long as the hourly values
events	as long as the hourly values