Signal Collector 0.9.0

THE WI-FI SCAN ADMITS WHEN THE SYSTEM THROTTLED IT

- Android limits how often Wi-Fi scans may run and keeps returning the same last result meanwhile. The app used to write it down again and again, so the export looked like sampling at the configured interval even though it was one measurement repeated over and over.
- Every scan attempt now writes a row with the state FRESH, THROTTLED or UNCHANGED and with the age of the result. Per-AP records are created only for a fresh scan.
- Three states instead of two: THROTTLED is a refused request, UNCHANGED means the same scan had been processed by the system callback moments earlier. UNCHANGED also grows where no throttling happens at all.
- Scans triggered by the system or another app are collected too. In the verification run that was 13 of 68 processed scans.

SCAN CADENCE: MEASURED

- Pixel 10a, Android 16, 5 s interval. With throttling on, 70 attempts were refused against 45 fresh scans. With throttling off, refusals dropped to zero.
- Without throttling a fresh scan arrives every 3.2 to 5.1 s, median 4.2 s. At walking pace that is roughly one sample every 6 metres against 40 metres before.
- Throttling can only be switched off with the "Wi-Fi scan throttling" toggle in the Developer options. Setting it through adb settings has no effect; the state is verified in dumpsys wifi.

POINT MEASUREMENT

- GPS gives no position indoors, so measured values have no way of reaching a floor plan. The new card has a field for a label and a Mark point button.
- A tap writes a marker with a sequence number, the label, the duration of the measurement and the distance walked, and buzzes briefly. The vibration is recorded too, so it can be told apart from real movement in the accelerometer.
- The procedure: stop, type the room number, mark the point, wait a moment, walk on.

THROUGHPUT OF INDIVIDUAL WI-FI NETWORKS

- One scan gives the signal of every network around at once; throughput does not — the phone is only ever associated with a single AP. A new optional source therefore visits the networks you list one by one and measures download, upload and HTTPS RTT on each.
- The switch applies to this app only; the rest of the phone's traffic stays on the original network.
- The connection time is recorded separately from the transfer times, otherwise there would be no telling a slow network from slow switching. The BSSID, signal, frequency, standard and link speed are stored with the result as well.
- A network that is not visible in the last scan is not attempted. For this way of connecting, Android opens a modal system dialog that does not disappear by itself even after the timeout and covers the whole app, Stop button included.
- Enterprise networks with 802.1X, typically eduroam, are not supported yet. The passwords of the measured networks sit in the app preferences in readable form.
- Sending the request, the behaviour of the dialog, honouring the timeout and writing the result are verified. A successful connection to a network and how long it really takes are not verified in the field.

EXPORT FORMAT

- The format stays SIGNAL_COLLECTOR_TXT_V4 and the database schema 5. The wifi_throughput source and the records for a scan and for a marked point were added; all of it is additive.