**** BEGIN LOGGING AT Sun Jan 09 02:59:56 2022
Jan 09 07:54:51 <KotCzarny> n9 is so dumb, 'you need sim card before you can use update time automatically'
Jan 09 07:55:16 <KotCzarny> even if you have wifi connected
Jan 09 07:55:34 <KotCzarny> what idiot thought it was a good design
Jan 09 08:51:01 <sicelo> isn't N900 like that too?
Jan 09 08:51:33 <sicelo> because they both don't do ntp time ootb, but do nitz instead, hence sim card
Jan 09 08:54:48 <KotCzarny> still, bad design
Jan 09 09:22:17 <sicelo> :-)
Jan 09 09:22:51 <sicelo> not sure if it's just mine, but i noticed android also doesn't do ntp natively ... they do nitz as well
Jan 09 09:29:50 <KotCzarny> maybe depends on version/build
Jan 09 09:30:08 <KotCzarny> mine always syncs time whenever there is any working net
Jan 09 09:42:23 <bencoh> maybe they didn't want to mess with it because of the side-effect it might have on some networks
Jan 09 09:47:53 <KotCzarny> then just add configurability, and let user decide
Jan 09 09:48:27 <KotCzarny> at this moment it doesnt work if someone wanted to use n9 as a wifi only calling/watching
Jan 09 09:49:03 <sicelo> https://source.android.com/devices/tech/connect/time-source ... at least all along, android preferred nitz.
Jan 09 09:49:20 <sicelo> just tested that adb command on my android 11 device, and sure enough, it gets nitz time
Jan 09 09:49:57 <KotCzarny> try disabling gsm , desynch time and check if it gets time with wifi
Jan 09 09:50:24 <sicelo> KotCzarny: why not install ntpdate or similar on the N9? at least that's what i did on my N900, and added an ifup hook. so each time i connect to a network, i get update instantaneously
Jan 09 09:50:47 <KotCzarny> sicelo, i'm not saying it's not possible, but ootb it's a bad design
Jan 09 09:51:15 <KotCzarny> and requires user to search for working repos, install few packages, etc
Jan 09 09:58:24 <sicelo> it does, but it's wrong
Jan 09 09:58:28 <sicelo> :-)
Jan 09 09:58:50 <sicelo> honestly, that's why even on android i installed an ntp client
Jan 09 09:59:22 <KotCzarny> i havent touched any droid higher than 8-9, so hard to say what they are doing now
Jan 09 09:59:29 <sicelo> or maybe i should take out my sim ... 
Jan 09 09:59:43 <KotCzarny> enable plane mode?
Jan 09 09:59:56 <KotCzarny> and turn on wifi, should be the same outcom
Jan 09 10:00:01 <sicelo> i was on plane mode
Jan 09 10:00:20 <sicelo> and got a time update, which is about 3 minutes behind the correct time
Jan 09 10:00:34 <KotCzarny> lol?
Jan 09 10:01:08 <sicelo> what?
Jan 09 10:01:26 <KotCzarny> 3 minutes desynch is a lot
Jan 09 10:01:42 <KotCzarny> unless you mean 'it got correct time with a delay of 3 min'
Jan 09 10:01:58 <sicelo> i'm sure it's nitz ... i know my operator's clock is out of sync (that's precisely why even on android i installed an ntp client)
Jan 09 10:03:07 <sicelo> just done it without sim. still time is wrong by almost 3 min ... i get correct date though
Jan 09 10:03:17 <sicelo> so yeah, no idea what's up with android and ntp 
Jan 09 10:04:05 <KotCzarny> i think you can call 112 without sim
Jan 09 10:04:15 <sicelo> of course
Jan 09 10:04:34 <sicelo> so yes ... i'm likely being nitz'd either way :D
Jan 09 10:05:01 <sicelo> that link from android.com says ntp is first preference from Android 12 onwards
Jan 09 10:05:18 <sicelo> so i'm sure you're also not really getting ntp time :P
Jan 09 10:05:26 <KotCzarny> but n9 is stubborn and doesnt want to get time wiithout *working* gsm network
Jan 09 10:07:16 <sicelo> now i have to juggle the time thing again on my phone :'(
Jan 09 10:07:44 <sicelo> because the ntp application isn't root (and phone isn't rooted), it can't set the time directly
Jan 09 10:08:01 <KotCzarny> dont have spare phone for tests?
Jan 09 10:09:07 <sicelo> i was testing on my recent Android 11 phone - my daily. I know the behavior of my Android 8 one since I used that one for even longer
Jan 09 11:59:07 <joerg> sicelo: isn't 3 min the offset meanwhile accumulated on raw GPS time?
Jan 09 12:11:18 <joerg> oops nope >>such that there is now an 18 second difference between GPS time and UTC time<<
Jan 09 12:12:29 <joerg> 3 minutes must be a total glitch of your NTP or NITZ
Jan 09 12:13:04 <drathir_tor> joerg: keep on mind gps sync (cold start) could take a time...
Jan 09 12:14:35 <drathir_tor> joerg: however not sure if gsm network sync is possible in emergency (no sim) connection mode...
Jan 09 12:17:01 <drathir_tor> joerg: in 4 and especially 5G that could in theory works bc them as good remember heavely operate at time based sync with bts but not sure if that shared with user...
Jan 09 12:30:00 <joerg> that's a good question but alas impossible to answer since the radio stacks are never open source
Jan 09 12:31:22 <joerg> just occurred to me right now that the modem might still _receive_ signals even in no_SIM / airplane mode
Jan 09 12:32:14 <joerg> then, it's indeed plausible the modem searches for carriers to do a 911 call when needed
Jan 09 12:32:48 <joerg> and searching for carrier means decoding the data in carrier
Jan 09 12:38:35 <drathir_tor> joerg: hmmm... not sure of that if passive listen have any reliable usage purposes even if able to collect nerby bts info in such mode i assume, but w/o actively ping the station for extra data them could be not as accurate i assume... like there is possible made list of backup tower to switch into, but w/o active ping tover the data could be too inaccurate for use...
Jan 09 12:43:08 <joerg> to ping a tower you first have to get to know of the frequency and ID of the tower, so the data is highly useful to shorten / eliminate the scanning time when dialing 911. Old featurefones had "select network / available networks" function that took up to several minutes to find all networks available in your location
Jan 09 12:43:48 <joerg> this data got even stored to sim so on next power-up the time needed to scan could get shortened
Jan 09 12:46:08 <bencoh> n900 has that too :)
Jan 09 13:06:27 <joerg> ok, directly from Harald Welte:  <LaF0rge> joerg: NITZ is in MM INFO, and that happens only over a fully-established bi-directional dedicated channel
Jan 09 13:07:11 <joerg> IOW no time data without SIM and login, or actually establishing a 911-call
Jan 09 13:20:08 <sicelo> maybe it wasn't nitz ... but whatever it is, it gives me time that's 3 minutes behind correct ntp time
Jan 09 13:20:44 <sicelo> anyway, i'd choose n900/n9 behavior any day, hehe. better to know you don't have correct time, than to think you have correct time, and wonder why your OTP codes don't work right
Jan 09 13:25:14 <joerg> :-)
Jan 09 13:25:58 <joerg> https://en.wikipedia.org/wiki/Mobility_management  MM INFO
Jan 09 13:41:54 <joerg> haha! >> Additionally, unlike 3GPP2, which transmits GPS-sourced, millisecond resolution time via the sync channel, for NITZ, the "accuracy of the time information is in the order of minutes".[<< https://en.wikipedia.org/wiki/NITZ
Jan 09 13:58:37 <joerg> >><sicelo> just done it without sim. still time is wrong by almost 3 min<< embedded RTC?
Jan 09 13:59:08 <sicelo> mmm, i don't know, but i doubt
Jan 09 14:00:42 <joerg> simple to test: wrap phone tightly into alu foil before powering up ;-)
Jan 09 14:03:21 <joerg> and don't get fooled by false assumptions like I were: I bought a dedicated microwave oven as poor man's faraday cage | anechoic chamber. Turned out the phone still had signal inside the oven
Jan 09 14:04:11 <joerg> lambda/2 seals, haha. Only work for a particular frequency they are tuned to
Jan 09 14:05:48 <KotCzarny> lol
Jan 09 14:06:00 <KotCzarny> isnt gsm freq lower than mw ?
Jan 09 14:06:15 <joerg> yep, GSM is
Jan 09 14:07:06 <joerg> 900/1800 vs microwave 2400
Jan 09 14:07:19 <joerg> or US: 850/1900
Jan 09 14:07:23 <KotCzarny> yeah, so it should block it to some extent
Jan 09 14:07:38 <KotCzarny> maybe phone had quite good sensitivity
Jan 09 14:09:02 <joerg> well, a lambda/2 seal works by tuning the exact geometry of a gap and edges to match the wavelength of the particular frequency you want to block. All other ferquencies (except odd harmonics) may pass 
Jan 09 14:09:46 <KotCzarny> well, foil the door then, i guess
Jan 09 14:09:52 <joerg> nowadays all microwave ovens use lambda/2 seals
Jan 09 14:25:47 <joerg> oh sorry, those are named lambda/4 seals
Jan 09 14:32:07 <joerg> aka quarter-wave choke
Jan 09 14:35:18 <joerg> https://patents.google.com/patent/US6867404B2/en
Jan 09 14:44:14 <joerg> also nice https://www.freepatentsonline.com/3956608.pdf same topic
Jan 09 14:44:52 <joerg> I could have known, learned it the hard way
Jan 09 15:01:24 <joerg> KotCzarny: indeed the signal was significantly attenuated, but not as much as would be needed to block out the phone from network
Jan 09 15:05:03 <joerg> actually if you own a microwave, it's very simple to test: place mobile phone into oven, DO NOT POWER OVEN UP, and - using a second phone - call the number off phone in oven
Jan 09 15:05:34 <KotCzarny> or even simpler, just look at the screen
Jan 09 15:05:51 <joerg> I just did and received a call without any indications of any problem
Jan 09 15:06:03 <KotCzarny> disabling screen blanking first though
Jan 09 15:06:25 <joerg> looking at the screen is a tad tricky inside microwave oven
Jan 09 15:06:34 <KotCzarny> mmm, flashlights
Jan 09 15:06:53 <KotCzarny> just kidding
Jan 09 15:06:57 <joerg> also doesn't tell you if the phone may transmit out of the chamber
Jan 09 15:06:59 <KotCzarny> scren is visible
Jan 09 15:07:29 <KotCzarny> wouldnt it lose conenctivity as it pings the tower periodically?
Jan 09 15:07:48 <joerg> phone starting to ring though is a clear indication of a two-way communication established between bts and phone
Jan 09 15:08:29 <joerg> phones don't ping bts very frequently, only up to once every 10 hours
Jan 09 15:08:43 <KotCzarny> still interesting fact, i would think that 0.5-1mm metal walls would block the gsm anyway
Jan 09 15:09:31 <joerg> the walls do, the o.5mm gap between door rim and oven body however only blocks 2400MHz
Jan 09 15:10:45 <joerg> I thought exactly like you, until I bought me an oven for exactly that purpose. 10 minutes after unboxing, I packed it back into its box ;-D
Jan 09 15:11:18 <KotCzarny> wouldnt just replacing the plastic seal with more metallic one help greatly?
Jan 09 15:12:23 <joerg> no, the opposite is true. The gap may be as small as a few micrometers. As long as there's no tight galvanic contact on 100% of area, such gap will leak mirowaves
Jan 09 15:13:06 <joerg> unless it's designed as quaterwave-choke, which you defeat by adding anything metallic there
Jan 09 15:14:34 <joerg> I seen very old comercial microwave ovens back in 1975 or somesuch, which indeed hat a metal fabric elastic seal and a plain stainless steel rim on oven body
Jan 09 15:14:44 <joerg> had*
Jan 09 15:15:26 <KotCzarny> so it would be possible to still convert it into a quite good faraday cage
Jan 09 15:16:56 <joerg> for this to work you need proper contact of fabric to door steel sheet 100% of length where it's mounted to door, and that fabric directly touching the metal body of oven when door closed
Jan 09 15:17:32 <joerg> and even then it's tricky to get those seals tight
Jan 09 15:18:20 <joerg> alternative: steel can (cookie can, coffee, sugar, whatever) with steel lid. May or may not work
Jan 09 15:18:47 <KotCzarny> might be too thin
Jan 09 15:19:13 <KotCzarny> but i guess phone ring test is easy to do
Jan 09 15:19:21 <joerg> if the lid has electrical contact to the can, it might work. No matter how "thin" the wall of the can
Jan 09 15:21:04 <joerg> what always works: alu foil bag, edges of foil carefully folded a 2 or 3 times
Jan 09 15:23:53 <joerg> or, if you're curious, use wire mesh, with mesh size <2mm
Jan 09 15:24:15 <joerg> instead of the alu foil
Jan 09 15:25:00 <joerg> yet to get tested: using rescue blanket, you can see through that one a maybe 0.1%
Jan 09 15:25:19 <joerg> probably too dark to read the display
Jan 09 15:25:58 <joerg> anyway rescue blanket has only one electrically conductive side, if at all
Jan 09 15:27:22 <joerg> so you'd need to make a real sack of one seamless piece tied together with a zip tie in one point
Jan 09 15:28:47 <joerg> silver side on the inside, hoping the zip tie will create some electrical contact between the pleats
Jan 09 15:31:15 <joerg> multi-layer, i.e. wrapping a sheet of foil several times around the phone, first one direction to form a tube, then rolling up the 2 ends of that tube several turns, should work too
Jan 09 15:32:21 <joerg> _should_, I'm not sure
Jan 09 15:36:18 <joerg> may only steel can I have here to test is filled with sugar :-/
Jan 09 15:36:25 <joerg> my*
Jan 09 15:36:39 <KotCzarny> i use plastic jars, with quite strong walls
Jan 09 15:37:00 <KotCzarny> it's nice to see what is inside
Jan 09 15:37:02 <KotCzarny> :)
Jan 09 15:37:26 <joerg> of course, but such stuff is almost unobtainium here meanwhile
Jan 09 15:37:45 <KotCzarny> put the phone inside pc case
Jan 09 15:37:47 <KotCzarny> :)
Jan 09 15:37:53 <joerg> well, at least not found frequently "in the wild"
Jan 09 15:37:57 <KotCzarny> j/k
Jan 09 15:38:39 <joerg> indeed a PC case is _supposed_ to be RF-tight. But usually isn't
Jan 09 15:39:06 <KotCzarny> yeah, lots of holes
Jan 09 19:19:37 <drathir_tor> sicelo: oh and in theory You should normally get ntp sync over wifi too...
Jan 09 19:22:04 <sicelo> theory is the keyword ;)
Jan 09 19:23:32 <sicelo> whatever the phone is using to get time sync when i'm on wifi with plane mode on or sim out, i get time that's 3 min behind. i guess that's ntp. as for what servers the thing uses, i'm not even sure i want to know
Jan 09 19:24:19 * drathir_tor now wonder if fridge would block better than microwave... ^^ ;p
Jan 09 19:24:56 <KotCzarny> fridge has a rubber seal on the door, ie. wide open for the em waves to go
Jan 09 19:25:23 <KotCzarny> https://source.android.com/setup/start/android-12-release
Jan 09 19:25:30 <KotCzarny> Starting in Android 12, the framework prioritizes the Network Time Protocol (NTP) time source over the Network Identity and Time Zone (NITZ) source by default.
Jan 09 19:25:38 <sicelo> at least using a real ntp client has been working reliably for me, so i'm good. android isn't really something i have patience to tweak a lot
Jan 09 19:26:18 <KotCzarny> https://source.android.com/devices/tech/connect/time-source
Jan 09 19:26:26 <KotCzarny> if you have adb you can try some commands
Jan 09 19:26:58 <KotCzarny> To check how the device time is set, run the following command:
Jan 09 19:26:58 <KotCzarny> adb shell dumpsys time_detector
Jan 09 19:27:29 <sicelo> i did :p
Jan 09 19:27:39 <sicelo> i pasted this link earlier
Jan 09 19:27:43 <KotCzarny> ahm
Jan 09 19:27:49 <KotCzarny> i just got back home
Jan 09 19:27:55 <KotCzarny> and didnt scroll far enough
Jan 09 19:28:07 <KotCzarny> anyway, it seems droid12 prefers ntp over nitz
Jan 09 19:28:14 <drathir_tor> sicelo: more crazy idea fm rds sync ?
Jan 09 19:28:34 <KotCzarny> adb shell settings put global ntp_server <new-ntp-server>
Jan 09 19:28:36 <sicelo> yes, i have 11 and 8, and 4 on the droid 4
Jan 09 19:29:09 <KotCzarny> adb shell settings get global ntp_server
Jan 09 19:29:17 <KotCzarny> check what it is configured to
Jan 09 19:29:51 <sicelo> and really, i'm happy with my setup on android with a third party ntp client. we were on N9/N900 :-)
Jan 09 19:29:57 <KotCzarny> :)
Jan 09 19:32:35 <sicelo> drathir_tor: sync time from fm? :D
**** ENDING LOGGING AT Mon Jan 10 02:59:56 2022