I’m trying to better understand how the AT+KNWSCANCFG command (Configure Network Scan Policy) works in practice with auto RAT switching. My goal is to restrict the search time for each RAT. From the documentation, the command defines min/max value intervals (in seconds) between scans, but it’s unclear to me what exactly is meant by “scans” in this context:
- Does “scan” refer to searching between bands within a RAT?
- Or does it refer to switching between RATs (e.g., LTE-M, NB-IoT, GSM)?
- Or is it something else entirely?
Experiment:
Here’s what I tried:
- RAT configuration:
AT+KSELACQ=1,2,3 - Enabled state event:
AT+KSTATEV=1 - Scan policy:
AT+KNWSCANCFG=1,0,15,45,10
Observation:
- Started searching for CAT-M at:
[2025-09-29 14:50:02.850] - Stopped searching for CAT-M and moved to another RAT at:
[[2025-09-29 15:04:56.372]]
This suggests that band configuration also influences search timing, but it’s still not clear to me how exactly the scan policy parameters control RAT/band search duration and retry intervals.
Question:
Can someone clarify how the scan policy defined by AT+KNWSCANCFG actually works? Specifically:
- What does “scan” refer to (band-level, RAT-level, or both)?
- How do the min/max interval values translate into actual RAT search timings?
- How does band configuration interact with the scan policy?
- When exactly does the scan exhaust and stop searching and move to the out-of-coverage case?
LOGs
[2025-09-29 14:47:49.356] +WDSI: 0
[2025-09-29 14:47:52.355] +KSUP: 0
[2025-09-29 14:48:00.595]
[2025-09-29 14:48:00.598] +CFUN: 4
[2025-09-29 14:48:00.600] OK
[2025-09-29 14:48:07.732]
[2025-09-29 14:48:07.735] +KSRAT: 0
[2025-09-29 14:48:07.735] OK
[2025-09-29 14:48:15.273]
[2025-09-29 14:48:15.276] +CFUN: 4
[2025-09-29 14:48:15.277] OK
[2025-09-29 14:48:20.779]
[2025-09-29 14:48:20.786] +KSELACQ: 1,2,3
[2025-09-29 14:48:20.788] OK
[2025-09-29 14:48:25.453]
[2025-09-29 14:48:25.478] +KNWSCANCFG: 0,1,2,30
[2025-09-29 14:48:25.482] +KNWSCANCFG: 1,0,15,45,10
[2025-09-29 14:48:25.486] OK
[2025-09-29 14:49:05.554] +CEREG: 5,0
[2025-09-29 14:49:05.554] OK
[2025-09-29 14:50:02.843] +CEREG: 2
[2025-09-29 14:50:02.850] +KSTATEV: 0,0
[2025-09-29 14:50:03.486] +CEREG: 0
[2025-09-29 14:50:03.494] +KSTATEV: 1,0
[2025-09-29 14:50:18.499] +KSTATEV: 0,0
[2025-09-29 14:50:18.508] +CEREG: 2
[2025-09-29 14:50:19.128] +CEREG: 0
[2025-09-29 14:50:19.133] +KSTATEV: 1,0
[2025-09-29 14:50:44.141] +KSTATEV: 0,0
[2025-09-29 14:50:44.153] +CEREG: 2
[2025-09-29 14:50:44.770] +CEREG: 0
[2025-09-29 14:50:44.777] +KSTATEV: 1,0
[2025-09-29 14:51:19.783] +KSTATEV: 0,0
[2025-09-29 14:51:19.795] +CEREG: 2
[2025-09-29 14:51:20.412] +CEREG: 0
[2025-09-29 14:51:20.417] +KSTATEV: 1,0
[2025-09-29 14:52:05.425] +KSTATEV: 0,0
[2025-09-29 14:52:05.432] +CEREG: 2
[2025-09-29 14:52:06.054] +CEREG: 0
[2025-09-29 14:52:06.059] +KSTATEV: 1,0
[2025-09-29 14:52:51.066] +KSTATEV: 0,0
[2025-09-29 14:52:51.075] +CEREG: 2
[2025-09-29 14:52:51.704] +CEREG: 0
[2025-09-29 14:52:51.710] +KSTATEV: 1,0
[2025-09-29 14:53:36.717] +KSTATEV: 0,0
[2025-09-29 14:53:36.725] +CEREG: 2
[2025-09-29 14:53:37.347] +CEREG: 0
[2025-09-29 14:53:37.352] +KSTATEV: 1,0
[2025-09-29 14:54:22.359] +KSTATEV: 0,0
[2025-09-29 14:54:22.368] +CEREG: 2
[2025-09-29 14:55:52.407] +CEREG: 0
[2025-09-29 14:55:52.414] +KSTATEV: 1,0
[2025-09-29 14:56:37.420] +KSTATEV: 0,0
[2025-09-29 14:56:37.428] +CEREG: 2
[2025-09-29 14:56:38.049] +CEREG: 0
[2025-09-29 14:56:38.053] +KSTATEV: 1,0
[2025-09-29 14:57:23.062] +KSTATEV: 0,0
[2025-09-29 14:57:23.077] +CEREG: 2
[2025-09-29 14:57:23.691] +CEREG: 0
[2025-09-29 14:57:23.697] +KSTATEV: 1,0
[2025-09-29 14:58:08.703] +KSTATEV: 0,0
[2025-09-29 14:58:08.712] +CEREG: 2
[2025-09-29 14:58:09.332] +CEREG: 0
[2025-09-29 14:58:09.338] +KSTATEV: 1,0
[2025-09-29 14:58:54.345] +KSTATEV: 0,0
[2025-09-29 14:58:54.359] +CEREG: 2
[2025-09-29 15:00:24.392] +CEREG: 0
[2025-09-29 15:00:24.396] +KSTATEV: 1,0
[2025-09-29 15:01:09.405] +KSTATEV: 0,0
[2025-09-29 15:01:09.413] +CEREG: 2
[2025-09-29 15:01:10.034] +CEREG: 0
[2025-09-29 15:01:10.036] +KSTATEV: 1,0
[2025-09-29 15:01:55.046] +KSTATEV: 0,0
[2025-09-29 15:01:55.054] +CEREG: 2
[2025-09-29 15:01:55.675] +CEREG: 0
[2025-09-29 15:01:55.678] +KSTATEV: 1,0
[2025-09-29 15:02:40.688] +KSTATEV: 0,0
[2025-09-29 15:02:40.697] +CEREG: 2
[2025-09-29 15:02:41.317] +CEREG: 0
[2025-09-29 15:02:41.319] +KSTATEV: 1,0
[2025-09-29 15:03:26.329] +KSTATEV: 0,0
[2025-09-29 15:03:26.338] +CEREG: 2
[2025-09-29 15:04:56.367] +CEREG: 0
[2025-09-29 15:04:56.372] +KSTATEV: 1,0
[2025-09-29 15:05:00.920] +CEREG: 2
[2025-09-29 15:05:00.938] +KSTATEV: 0,1
[2025-09-29 15:05:01.445] +CEREG: 0
[2025-09-29 15:05:01.448] +KSTATEV: 1,1
[2025-09-29 15:05:16.458] +KSTATEV: 0,1
[2025-09-29 15:05:16.476] +CEREG: 2
[2025-09-29 15:05:16.960] +CEREG: 0
[2025-09-29 15:05:16.963] +KSTATEV: 1,1
[2025-09-29 15:05:41.975] +KSTATEV: 0,1
[2025-09-29 15:05:41.983] +CEREG: 2
[2025-09-29 15:05:42.477] +CEREG: 0
[2025-09-29 15:05:42.479] +KSTATEV: 1,1
[2025-09-29 15:06:17.490] +KSTATEV: 0,1
[2025-09-29 15:06:17.504] +CEREG: 2
[2025-09-29 15:06:17.992] +CEREG: 0
[2025-09-29 15:06:17.994] +KSTATEV: 1,1
[2025-09-29 15:07:03.006] +KSTATEV: 0,1
[2025-09-29 15:07:03.013] +CEREG: 2
[2025-09-29 15:07:03.509] +CEREG: 0
[2025-09-29 15:07:03.512] +KSTATEV: 1,1
[2025-09-29 15:07:48.522] +KSTATEV: 0,1
[2025-09-29 15:07:48.535] +CEREG: 2
[2025-09-29 15:07:49.023] +CEREG: 0
[2025-09-29 15:07:49.028] +KSTATEV: 1,1
[2025-09-29 15:08:34.037] +KSTATEV: 0,1
[2025-09-29 15:08:34.044] +CEREG: 2
[2025-09-29 15:08:34.540] +CEREG: 0
[2025-09-29 15:08:34.545] +KSTATEV: 1,1
[2025-09-29 15:09:19.553] +KSTATEV: 0,1
[2025-09-29 15:09:19.560] +CEREG: 2
[2025-09-29 15:10:57.653] +CEREG: 0
[2025-09-29 15:10:57.657] +KSTATEV: 1,1
[2025-09-29 15:11:42.664] +KSTATEV: 0,1
[2025-09-29 15:11:42.672] +CEREG: 2
[2025-09-29 15:11:43.168] +CEREG: 0
[2025-09-29 15:11:43.170] +KSTATEV: 1,1
[2025-09-29 15:12:28.180] +KSTATEV: 0,1
[2025-09-29 15:12:28.189] +CEREG: 2
[2025-09-29 15:12:28.683] +CEREG: 0
[2025-09-29 15:12:28.685] +KSTATEV: 1,1
[2025-09-29 15:13:13.696] +KSTATEV: 0,1
[2025-09-29 15:13:13.704] +CEREG: 2
[2025-09-29 15:13:14.199] +CEREG: 0
[2025-09-29 15:13:14.202] +KSTATEV: 1,1
[2025-09-29 15:13:59.211] +KSTATEV: 0,1
[2025-09-29 15:13:59.219] +CEREG: 2
[2025-09-29 15:15:37.311] +CEREG: 0
[2025-09-29 15:15:37.321] +KSTATEV: 1,1
[2025-09-29 15:16:22.324] +KSTATEV: 0,1
[2025-09-29 15:16:22.331] +CEREG: 2
[2025-09-29 15:16:22.827] +CEREG: 0
[2025-09-29 15:16:22.829] +KSTATEV: 1,1
[2025-09-29 15:17:07.840] +KSTATEV: 0,1
[2025-09-29 15:17:07.850] +CEREG: 2
[2025-09-29 15:17:08.342] +CEREG: 0
[2025-09-29 15:17:08.343] +KSTATEV: 1,1
[2025-09-29 15:17:53.355] +KSTATEV: 0,1
[2025-09-29 15:17:53.367] +CEREG: 2
[2025-09-29 15:17:53.858] +CEREG: 0
[2025-09-29 15:17:53.863] +KSTATEV: 1,1
[2025-09-29 15:18:38.871] +KSTATEV: 0,1
[2025-09-29 15:18:38.879] +CEREG: 2
[2025-09-29 15:20:16.960] +CEREG: 0
[2025-09-29 15:20:16.963] +KSTATEV: 1,1
[2025-09-29 15:20:22.318] +KSTATEV: 0,2
[2025-09-29 15:20:22.946] +KSTATEV: 1,2
[2025-09-29 15:20:29.074] +CEREG: 2
[2025-09-29 15:20:29.097] +KSTATEV: 0,0
[2025-09-29 15:20:29.727] +CEREG: 0
[2025-09-29 15:20:29.731] +KSTATEV: 1,0
[2025-09-29 15:20:44.740] +KSTATEV: 0,0
[2025-09-29 15:20:44.763] +CEREG: 2
[2025-09-29 15:20:45.367] +CEREG: 0
[2025-09-29 15:20:45.371] +KSTATEV: 1,0
[2025-09-29 15:21:10.381] +KSTATEV: 0,0
[2025-09-29 15:21:10.389] +CEREG: 2
[2025-09-29 15:21:11.009] +CEREG: 0
[2025-09-29 15:21:11.012] +KSTATEV: 1,0
[2025-09-29 15:21:46.023] +KSTATEV: 0,0
[2025-09-29 15:21:46.031] +CEREG: 2
[2025-09-29 15:21:46.652] +CEREG: 0
[2025-09-29 15:21:46.656] +KSTATEV: 1,0
[2025-09-29 15:22:31.665] +KSTATEV: 0,0
[2025-09-29 15:22:31.681] +CEREG: 2
[2025-09-29 15:22:32.293] +CEREG: 0
[2025-09-29 15:22:32.298] +KSTATEV: 1,0
[2025-09-29 15:23:17.305] +KSTATEV: 0,0
[2025-09-29 15:23:17.314] +CEREG: 2
[2025-09-29 15:23:17.936] +CEREG: 0
[2025-09-29 15:23:17.941] +KSTATEV: 1,0
[2025-09-29 15:24:02.948] +KSTATEV: 0,0
[2025-09-29 15:24:02.963] +CEREG: 2
[2025-09-29 15:24:03.577] +CEREG: 0
[2025-09-29 15:24:03.582] +KSTATEV: 1,0
[2025-09-29 15:24:48.590] +KSTATEV: 0,0
[2025-09-29 15:24:48.598] +CEREG: 2
[2025-09-29 15:26:18.638] +CEREG: 0
[2025-09-29 15:26:18.640] +KSTATEV: 1,0
[2025-09-29 15:27:03.650] +KSTATEV: 0,0
[2025-09-29 15:27:03.658] +CEREG: 2
[2025-09-29 15:27:04.279] +CEREG: 0
[2025-09-29 15:27:04.281] +KSTATEV: 1,0