[HN Gopher] Apple Maps location scan spikes WiFi latency every 6...
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       Apple Maps location scan spikes WiFi latency every 60 seconds
        
       Author : ivank
       Score  : 640 points
       Date   : 2022-05-12 16:56 UTC (1 days ago)
        
 (HTM) web link (twitter.com)
 (TXT) w3m dump (twitter.com)
        
       | whazor wrote:
       | Best is to disable location services, which results into multiple
       | disadvantages:
       | 
       | - maps don't show your location, which you would have to live
       | with..
       | 
       | - I recommend F.lux instead of night shift and dark mode: you can
       | manually configure a location in F.lux and let it enable dark
       | mode as well.
       | 
       | - also manually set time zone
        
       | pabs3 wrote:
       | Why do network scans spike latency? Seems like a WiFi firmware
       | bug to me. I wonder if it happens with open source WiFi firmware
       | like ath9k_htc.fw
       | 
       | https://github.com/qca/open-ath9k-htc-firmware
        
         | op00to wrote:
         | Wifi chipsets can't scan networks and do regular wifi-y stuff
         | at the same time.
        
           | kalleboo wrote:
           | That seems odd, when they can connect to 2 networks at the
           | same time
        
             | octoberfranklin wrote:
             | Only if either (a) both networks use the same channel or
             | (b) the networks use different bands (i.e. one is 5ghz and
             | the other is 2.4ghz).
             | 
             | In order to scan usefully you need to listen on more than
             | one channel from each band. Hence, the interruptions.
             | 
             | I suppose in theory if you were using a 5ghz network you
             | could scan all the 2.4ghz frequencies. In practice there is
             | little demand for this, so the proprietary firmwares don't
             | support it (at least some, and often all, of the scan
             | routine happens in firmware).
        
               | kalleboo wrote:
               | This is really interesting so I did an experiment.
               | 
               | I connected my iPhone to a 5 GHz-only network on channel
               | 36, and my MacBook Pro to a 5 GHz-only network on channel
               | 48, and I could still AirDrop between them at 300 MBit
               | (which exceeds any real-world speed I've seen on 2.4
               | GHz), and both devices retained connectivity (an iperf on
               | the MacBook dropped from 600 Mbit to 300 Mbit while the
               | AirDrop was in progress)
               | 
               | After messing around with this and sending around 10
               | AirDrops, now the feature is completely broken no matter
               | what I do (same network, etc) so who knows (lol)
        
         | octoberfranklin wrote:
         | It does not.
         | 
         | The latency is also massively better -- I surgically implanted
         | an "ancient" ath9k into my laptop and 5ghz wifi latencies
         | dropped 6x compared to the "modern" broadcom chip on the
         | laptop's motherboard. Still getting 300mbit/sec.
         | 
         | All it cost me was the left speaker, removed to make space for
         | the superior wifi card with open-source firmware.
         | 
         | Kinda makes you go "hrm."
        
           | pabs3 wrote:
           | Which ath9k card did you get?
        
             | octoberfranklin wrote:
             | A very obscure module used inside of smart TVs, for a
             | number of reasons -- one of them being the fact that it has
             | exposed serial console pins.
             | 
             | If you're just starting out, stick to something easier like
             | the Sony UWA-BR100:
             | 
             | https://h-node.org/wifi/view/en/1283/Sony-UWA-
             | BR100-802-11ab...
             | 
             | There are a bunch of these 5ghz ath9k USB sticks, all of
             | which are basically the same ar7010/ar9280 reference design
             | from atheros with different plastic housings around them.
        
       | alaricus wrote:
       | That can't be good for the battery life.
        
         | nojito wrote:
         | The default battery claims have location services turned on.
        
           | ComputerGuru wrote:
           | I don't think this does anything if maps isn't running?
        
             | urbandw311er wrote:
             | Interestingly, when I went to Security Preferences there
             | was an icon to show that Apple Maps had used my location in
             | the last 24 hours. This is in spite of almost _never_ using
             | Apple Maps on my MacBook, and certainly not in the last
             | month. So this smells like some sort of background daemon
             | or similar.
        
               | KennyBlanken wrote:
               | Hmm.
               | 
               | Did you hop into a vehicle you have paired with
               | bluetooth? Apple Maps drops a "parked car" pin
               | automatically when you do, I think regardless of whether
               | it was in use at the time.
               | 
               | Maybe you used an app that uses an Apple Maps view?
               | 
               | Do you have any of the drive-time/traffic condition
               | widgets active in the lefthand thingy, or homescreen?
        
               | ComputerGuru wrote:
               | While some platforms go through the Maps app to get the
               | location, under macOS/iOS there's the locationd daemon
               | that provides the location independently of any app.
               | There, Maps is just a locationd consumer just like any
               | other app requesting a location so Maps _shouldn 't_ be
               | invoked in the background by non-Maps stuff. But perhaps
               | Maps has a timed trigger to background update your cached
               | location (so it can open up to the correct startup
               | location instead of locating you after startup) or
               | something similar.
        
       | defen wrote:
       | Is this the "weird WiFi latency on Mac OS" thread? I've got a
       | WiFi network with a MacBook Pro (running 11.6 because I hate
       | upgrading) and a System76 linux box (as well as lots of other
       | devices). Both of the machines can ping a google dot com server
       | (which is approximately 150 miles away, going by the hostname)
       | consistently in the 8-12 ms range.
       | 
       | Pinging the System76 box from the laptop, the latency varies from
       | 2-250(!) ms. Pinging the laptop from the System76 box varies from
       | 2-125ms.
       | 
       | I don't even know where to start debugging that but the latency
       | is driving me crazy.
        
       | bemmu wrote:
       | I see system_profiler doing a scan when I gather the logs. Is
       | that just the logger itself doing something, and if not is there
       | a way to find what it invoking system_profiler?
        
       | phineyes wrote:
       | It's not just Apple Maps either! Even with location services
       | disabled, try opening AirDrop (even on another device you own)
       | while running a ping and you'll see your en0 device's latency
       | spike, while Apple tries to divide traffic between awdl0 and en0.
        
       | rootusrootus wrote:
       | I cannot replicate this on my M1 MBP running 12.3.1.
        
         | can16358p wrote:
         | Same. Have been trying for minutes with the same software
         | running and on Wi-Fi. All pings around 4ms with no spikes at
         | all.
        
         | acchow wrote:
         | Same. Not able to replicate on M1 MBA
         | 
         | Aren't modern Wifi chips capable of holding two simultaneous
         | connections (one for wifi, one for wifi-direct/Airdrop)?
        
         | fragmede wrote:
         | This happens on my M1 Macbook Air running 12.0.1 and is
         | extremely evident when playing games on Stadia, unless location
         | services is disabled.
        
           | diebeforei485 wrote:
           | Why are you still running 12.0.1?
        
       | tda wrote:
       | I noticed this too when I used steam to stream a game to my
       | laptop over good wifi. Every minute it would stutter for a
       | second. I set up iperf3 tests and noticed the wifi lag increasing
       | every minute between my macbook and my server and between my
       | windows desktop pc and my server (when connected over wifi). Of
       | course no lag when using cables, so I reasoned it was wifi
       | related, and had noting to do with my setup (I used different
       | clients, and different AP's). I then took my macbook (only
       | portable computer I had) it too a nearby coffee shop with good
       | wifi and I could still measure lag spikes every minute. So then I
       | was really puzzled, was there some rogue device interfering with
       | wifi all over the neighborhood? Finally I found a suggestion to
       | turn off location services (or whatever it is called), and the
       | spikes disappeared. And I learnt that even when it is not used
       | (not sure it the lid was closed) a macbook can cause significant
       | interference to the wifi for all other nearby devices.
        
         | 867-5309 wrote:
         | if you have the wherewithal to use iperf then why not wireshark
         | too? it's probably actively sniffing surrounding wifi frames to
         | feed back to its proprietary version of WiGLE.net under the
         | guise of super helpful "location based services"
        
         | tomxor wrote:
         | > And I learnt that even when it is not used (not sure it the
         | lid was closed) a macbook can cause significant interference to
         | the wifi for all other nearby devices.
         | 
         | My partner has an older MBP, I noticed this the last time she
         | was forced to updated her OS a major version... the thing no
         | longer sleeps when you tell it to or when you close the lid, it
         | will stay connected to wifi and quite happily saturate the
         | network downloading updates.
         | 
         | Only way to be sure is to power off the stupid thing.
        
           | Abishek_Muthian wrote:
           | Yesterday my home DNS weren't resolving and noticed on PiHole
           | that there were >30,000 requests of *.in-addr.arpa (Reverse
           | DNS Lookup) from the iPhone+iPad of the guest to whom I gave
           | the WiFi access and was saturating the Pi's CPU. I re-enabled
           | rate limiting on PiHole and blocked the request with a
           | filter.
           | 
           | A cursory search on the issue says Bonjour is the culprit,
           | I'm forwarding DNS requests to my PiHole instances on my
           | gateway and latest iOS doesn't seem to like it; I haven't
           | faced such issue earlier and I have this setup for several
           | years now.
        
           | code_duck wrote:
           | My understanding is this is an issue with new features of all
           | sorts of laptop/desktop devices.
           | 
           | For example, https://news.ycombinator.com/item?id=28639952
           | 
           | "Do not leave XPS laptop in any sleep/hibernate/standby mode
           | when placed in a bag" because they stay connected to wifi and
           | may attempt to run updates etc when the user is not expecting
           | or prepared for that, as far as cooling.
        
             | tomxor wrote:
             | I own an XPS, it runs Debian, it only installs updates when
             | I tell it to.
             | 
             | Even if I decided to use the untended upgrades package, it
             | wouldn't do it when I sleep the computer... that would just
             | be stupid.
        
               | alimov wrote:
               | Yeah it might be unwanted behavior for your particular
               | setup. Personally, on macOS and windows, I would prefer
               | not to be at the computer when an update occurs - I also
               | dont want to have to go do something else while I wait
               | for the update. Just feels like a waste of time in my
               | opinion. However, if I had reason to care about an update
               | or the changes it was introducing I too would not want
               | background updates running when I put my machine to
               | sleep. I guess for an average user updating when the
               | machine is not in use is a feature, while for the tech
               | crowd that kind of behavior can mess with your preferred
               | setup.
        
               | beowulfey wrote:
               | Running updates are only a problem on Mac or Windows.
               | Updates on the different linux flavors I've used take
               | fractions of the time, are unobtrusive (I can continue to
               | do work), and as a bonus, never fail to make my aging
               | self feel like a technoir hacker with all that rapidly
               | scrolling text. It's all whole different ball game.
        
               | danieldk wrote:
               | Different user groups, different priorities. I had a
               | colleague who was a seasoned C hacker and long-time Linux
               | user (but not someone who'd be very interested in how a
               | Linux distribution or package manager works). Their
               | Ubuntu system indicated that there were updates. So, they
               | started the update. However, it was taking too much time
               | and they wanted to go home, so they shut down the machine
               | during the update. Unfortunately, it left the system in a
               | bad, (IIRC) unbootable state and the local sysadmin had
               | to spend an hour to get the system in a consistent state
               | again.
               | 
               | Is it reasonable to expect that you can just yank the
               | chord during an upgrade? Maybe, maybe not. But users have
               | the expectation that it is ok, there can be a power
               | interruption after all.
               | 
               | This would never happen with a macOS update, which uses
               | an immutable root file system and APFS containers to
               | switch the root after an update. Or an OSTree system like
               | Silverblue, Fedora IOT, or Fedore CoreOS. Traditional
               | Linux packages fall flat on their face in such scenarios
               | (unless you use a lot of band-aid like filesystem
               | snapshots, set up GRUB to handle boot into the right
               | snapshot, etc.)
               | 
               | I think it is uncharitable to assume that the people
               | making macOS (or Windows) update are incompetent. They
               | may just have a different set of requirements and
               | constraints.
        
               | beowulfey wrote:
               | That's a good story. I thought apt can usually recover
               | from incomplete updates, but maybe it was in the middle
               | of a kernel or bootloader update or something when power
               | got killed.
        
               | tomxor wrote:
               | > This would never happen with a macOS update, which uses
               | an immutable root file system and APFS containers to
               | switch the root after an update.
               | 
               | There are still things that cannot be interrupted like
               | flashing firmware blobs, on many devices. Before apple
               | distributed updates using FS snapshots they would reboot
               | the machine first and block the user with a message that
               | it cannot be interrupted.
               | 
               | It's also not a completely free or well implemented
               | solution because (even as an x-apple user) I am made
               | patently aware of just how absurdly huge their updates
               | are, even for the smallest patch... incremental
               | distribution and immutable FS based updates are not
               | fundamentally incompatible, so I guess Apple simply
               | doesn't respect user's bandwidth or assumes all of their
               | customers have gigabit downlinks for the exclusive use of
               | Apple devices.
        
               | tharkun__ wrote:
               | I always assumed it was smart enough though _not_ to do
               | it when it 's on battery as it is very likely that the
               | device is also in a confined space, such as a laptop
               | backpack waiting for the trip to the office next morning.
               | 
               | If I have it sitting on power and thus likely just on the
               | top of the table and I have auto-updates on, sure do them
               | when I'm not around as long as they are updates that can
               | run unattended. Note the "if auto-updates are on" part,
               | which luckily you _can_ still disable on MacOS.
        
               | alimov wrote:
               | I think macOS has a minimum battery charge requirement
               | that has to be met before an update occurs in the
               | unplugged scenario.
        
               | emkoemko wrote:
               | people on linux wait for updates? i thought that was a
               | thing only for mac and windows... never noticed or seen a
               | update screen on linux unlike the Windows nightmare where
               | it would even kick you out of your work to do a damn
               | update
        
               | alimov wrote:
               | Don't know what people on Linux do, I only referenced
               | macOS and windows.
        
               | danieldk wrote:
               | _people on linux wait for updates?_
               | 
               | Yes, Fedora downloads packages first and then reboots the
               | machine to perform the actual updates and then reboots
               | again into the updated system [1]. You can still run _dnf
               | update_ manually, but the recommended path is the former
               | one. Why? Because in contrast to what many commenters say
               | here, in-place updates of Linux systems can go wrong.
               | Apparently, Fedora have encountered this often enough
               | that they they have started doing  'offline updates'.
               | 
               | (The proper solution, which Silverblue/Fedora IoT/Fedora
               | coreOS/NixOS/GUIX do is to make system updates atomic
               | with roll-back.)
               | 
               | [1] https://fedoramagazine.org/offline-updates-and-
               | fedora-35/
        
               | emkoemko wrote:
               | just checked how Fedora does it... it just downloads the
               | updates and when you shutdown it installs them for you
               | before it finally shuts down, doesn't seem as bad and not
               | how you said it was.
        
             | Schroedingersat wrote:
             | Or do. Then get refund when it cooks itself and buy a
             | computer you own.
        
               | zitterbewegung wrote:
               | Dunno if the new MacBook Pro M1 Pro / Max are more
               | thermally efficient or that they don't start back up in a
               | bag but I've left mine in sleep in a sealed bag and it
               | wasn't warm to the touch at all.
        
               | pegasus wrote:
               | Did you have auto-update on?
        
               | zitterbewegung wrote:
               | Yes
        
               | pegasus wrote:
               | There probably were just no updates available at the
               | time.
        
               | zitterbewegung wrote:
               | Considering I'm on the beta channel because I have dev
               | account I don't think that's true.
        
             | edb_123 wrote:
             | I have had this issue with Thinkpads as well. The solution
             | was to make sure to unplug the AC power adapter _before_
             | putting it to sleep and putting it in my bag. Else it would
             | go to sleep thinking that it 's still on AC power, and
             | happily wake itself up to install updates while in my bag.
             | If power was disconnected _after_ putting it to sleep, it
             | would not be able to know it was on battery power.
        
           | astrange wrote:
           | https://support.apple.com/guide/mac-help/turn-power-nap-
           | on-o...
        
             | tomxor wrote:
             | Tried it, didn't work, I also dug out the old pmset command
             | but it seems to have been neutered.
             | 
             | I'm glad I stopped using Apple stuff 10 years ago, their
             | macs are gradually devolving into iDevices.
        
               | astrange wrote:
               | Sleep isn't any different than it used to be.
               | 
               | "pmset -g assertions" will show you why it thinks it's
               | awake, it could be a silent video playing in a web
               | browser or something. (and of course, if you can ssh in
               | to run that it must be awake.)
        
               | IAmEveryone wrote:
               | they already mentioned why it was awake: downloading
               | updates.
               | 
               | ...which it only does when connected to power so I'm
               | honestly failing to understand what the problem may be.
               | Anyway: Settings -> Software updates -> Advanced ->
               | Download new updates when available -> uncheck.
               | 
               | For everything else: Battery -> Power adaptor -> Wake for
               | network access -> uncheck (may also take care of the
               | above, dunno)
        
         | hoten wrote:
         | Wow, I guess this is also why my local steam streaming (well, I
         | use Moonlight but same difference) started lagging out of
         | nowhere. I first noticed it 2 days ago, but before that I
         | clocked 30 hours no problem, so I guess this is a brand new
         | problem.
         | 
         | Gonna try turning off all my Mac devices location services,
         | thanks for the tip.
        
           | [deleted]
        
           | tda wrote:
           | This was a few years ago on a 2015 MBP running Catalina or
           | whatever came before that. My guess is the adaptive bandwidth
           | algorithm acutely switches to a lower bandwidth due to the
           | lag spike, and then slowly recovers in the ten seconds after.
           | And then 50 seconds later it starts over again. I suspect if
           | I could have manually set the streaming quality to a fixed
           | value the lag spike would hardly not be noticable at all, but
           | the constant switching of the stream quality is what actually
           | caused chopiness. Same might be the case with the OP's zoom
           | calls
        
         | draebek wrote:
         | People doing game streaming might be interested in this bug in
         | the moonlight-qt repo that discusses people having this same
         | problem, including various fixes: https://github.com/moonlight-
         | stream/moonlight-qt/issues/159
        
           | trafficante wrote:
           | Can confirm that the scripts posted itt by vJan00 [0] solved
           | the stuttering problems that were plaguing me 4-5 months ago.
           | Didn't bother setting up a cronjob; I just toggle it on/off
           | as needed.
           | 
           | [0] https://github.com/moonlight-stream/moonlight-
           | qt/issues/159#...
        
       | ncann wrote:
       | On Windows, there was an infamous Qt bug that also caused regular
       | ping spike, so check it out if you have the issue and you also
       | happen to be using a Qt program:
       | 
       | https://bugreports.qt.io/plugins/servlet/mobile#issue/QTBUG-...
        
       | brohoolio wrote:
       | I've seen this sporadically. A reboot clears it for me. I
       | probably spent a good hour trying to figure out if it was my ISP
       | or router. Improve your QA Apple
        
       | jokoon wrote:
       | Other anecdote: I have a thinkpad L450, and randomly during the
       | day, the wifi firmware just "crashes" and disable itself, and
       | needs to be reset via the "troubleshoot" dialog in windows 10.
       | 
       | It's quite annoying, and I can't really think of why it happens.
       | 
       | I wonder if radio interference might be a cause.
        
       | Angostura wrote:
       | Silly question - but does this problem occur only when Maps is
       | running? Or is there a background daemon doing this stuff?
       | 
       | I've never had this problem on my iMac
        
       | boesboes wrote:
       | So I've tried this and cannot reproduce anything like it. Yes,
       | when I tell Macos to scan for network, there is a short latency
       | spike, as can be expected. But _only_ when I open up the networks
       | menu.
       | 
       | I have maps open, refresh my location etc. Nothing at all. So
       | there must be some other factors at play. Given the authors
       | wireless woes that I've never had trouble with, I feel like they
       | might just be living in a bunch of farayday cages ;)
        
       | goodoldneon wrote:
       | Location services in general seem to cause latency spikes for me.
       | I just disabled the feature altogether
        
       | gernb wrote:
       | Is this why Airplay no longer works? As of MacOS 12.3 when I
       | AirPlay from M1 to AppleTV every ~2 minutes it drops to ~1fps for
       | ~30 seconds.
        
         | wintermutestwin wrote:
         | Look into issues with Dolby Atmos on AppleTV and your soundbar.
        
       | robbomacrae wrote:
       | As a means to keeping this feature on when out in public, but not
       | have it cause latency spikes at home, is it possible to configure
       | the router to block these requests from location services? Or do
       | we need to setup each device to automatically disable location
       | services when on the house wifi?
        
         | lxgr wrote:
         | Wifi positioning does not actively talk to the network you're
         | connected to, but rather does a beacon frame sweep and then
         | matches BSSIDs seen with some database.
         | 
         | One side effect of this is that in order to scan all possible
         | wifi channels, your baseband needs to tune to different
         | frequencies at least for a short period of time.
         | 
         | Theoretically this interval should be short enough to avoid any
         | disruptions - practically that's apparently not always the
         | case.
        
       | a-dub wrote:
       | lol. i wonder if it's quietly popping the nic out of the
       | associated state, quickly scanning for aps and then jumping back
       | where it left off without telling userland or the remote ap that
       | anything happened...
        
         | qwertywert_ wrote:
         | Background scanning is a normal WiFi feature, you don't break
         | association state when doing this. It is required for regular
         | and fast roaming.
         | 
         | Also it must be notifying userland it happened because location
         | services is trying to gather that info.
         | 
         | Most WiFi clients enable background scanning when signal
         | strength is below some threshold, so you would never notice
         | latency spikes unless connection is already poor.
        
           | a-dub wrote:
           | interesting. so they just switch it on even when the signal
           | is strong.
           | 
           | > Most WiFi clients enable background scanning when signal
           | strength is below some threshold, so you would never notice
           | latency spikes unless connection is already poor.
           | 
           | i assume s/unless/because/ ?
        
       | dpcx wrote:
       | I just tried this myself and can't replicate on a 2019 i7 running
       | Big Sur. I wonder if it's related to the number of Wifi networks
       | in range (mine is the only one)... Also, the Apple Maps thing
       | didn't seem to change anything for me, either.
        
         | foobarian wrote:
         | Environment can have huge impact on this. With a larger number
         | of devices, there could be more collisions, increasing traffic
         | more than linearly, and then in case of scanning traffic, the
         | modulation used would likely be the lowest available which
         | means the packets take up a lot of wall clock time. So a
         | broadcast storm with collisions, retries, at the lowest bitrate
         | = brief outage.
        
         | altairprime wrote:
         | How many saved wireless networks do you have?
        
       | londons_explore wrote:
       | It's 2022. Apple should just have a separate WiFi radio for
       | location scans.
        
       | Nextgrid wrote:
       | I wonder why they keep rescanning the wifi environment even
       | though the fact that it remains connected to the same BSSID and
       | the RSSI doesn't fluctuate too much should suggest that it's very
       | unlikely the device moved far enough to warrant another scan.
        
         | tedunangst wrote:
         | locationd probably wasn't tracking that state. Maybe now it is.
        
         | judge2020 wrote:
         | I imagine they have to handle the scenario where you're
         | connected to a mobile access point and can't assume that 0
         | movement means you're in the same physical location. Watching
         | other APs is going to provide a better picture.
        
         | TSiege wrote:
         | portable wifi? edge case, but its possible this was the fix for
         | it
        
         | IAmEveryone wrote:
         | What's the newest Wifi standard? ax? Anyway: it's quite...
         | something? My standard router runs four different networks on
         | two different IDs and if I understand it correctly, the fasted
         | frequencies are subject to occasional use by... my local
         | Patriot air defense system(?) which it needs to occasionally
         | check for.
        
           | paranoidrobot wrote:
           | > the fasted frequencies are subject to occasional use by...
           | my local Patriot air defense system(?)
           | 
           | I think you're you're talking about Radar detection?
           | 
           | My apartment is on the approach-path for one runway of a
           | major airport - I regularly get reports of Radar detection on
           | my Unifi APs when planes are landing in this direction.
        
         | Bud wrote:
         | You're forgetting how sensitive this location detection is,
         | these days. Let's say you are moving in a direction roughly
         | parallel to the circle carved out by a given signal strength.
         | You could move quite a long ways without RSSI fluctuating much.
        
         | Zelizz wrote:
         | My anecdotal experience (partially informed by working on the
         | Windows Wi-Fi team) is that iOS/macOS are more aggressive about
         | switching APs. It's a tradeoff - on one hand, you can have
         | disruptive scans like this, but on the other, if it results in
         | switching to a better network during a long period when the
         | user is stationary, it can result in a better experience.
         | 
         | It also depends a lot on what your hardware is, whether you're
         | doing a full scan or a partial scan, whether you have more than
         | one NIC etc, etc.
        
           | not2b wrote:
           | "better experience" only if you aren't doing something
           | latency-sensitive, like a video call.
        
             | Gigachad wrote:
             | Video calls aren't hyper latency sensitive, there is
             | already a lot of latency in encoding and processing
             | effects. I'd imagine this could be most disruptive to video
             | games but this isn't a market Apple has done much to work
             | with.
        
               | gsich wrote:
               | 1% packetloss is audible.
        
         | [deleted]
        
         | spookthesunset wrote:
         | Maybe it wasn't a problem worth fixing at the time? Maybe
         | they'll do exactly this in future versions of the location
         | finder stack.
         | 
         | Edit: somebody pointed out that these scans could be for
         | roaming purposes as well. Maybe there is another access point
         | with a better signal and it's time to move?
        
       | GekkePrutser wrote:
       | Ok that sucks. If they do a scan, at least use the radio that's
       | not in use so it doesn't affect the one communicating (e.g. use
       | 2.4 Ghz when you're connected on 5).. That would be a good way to
       | avoid this latency hit.
       | 
       | Also, I'm assuming Maps only does this when it's open, but
       | Apple's annoying tendency to keep an app running when you close
       | the last window (with the exception of system preferences and a
       | few others) makes this very hard to diagnose. While I still used
       | Macs a lot I would always close apps with Command-Q for that
       | reason. This behaviour would exacerbate the problem as the user
       | isn't aware that the app is stil running.
       | 
       | Apple's reasoning is I believe to "not worry about open apps, the
       | OS will handle it". But it doesn't always, I often get prompts
       | that my memory is full and I have to close something now or
       | else... And that is with me being rigorous closing apps. My work
       | buys only base level machines with standard ram, unfortunately.
        
         | judge2020 wrote:
         | > Ok that sucks. If they do a scan, at least use the radio
         | that's not in use so it doesn't affect the one communicating
         | (e.g. use 2.4 Ghz when you're connected on 5).. That would be a
         | good way to avoid this latency hit.
         | 
         | Is this possible? Or is AP scanning perhaps always over 2.4?
        
         | JoeAltmaier wrote:
         | Often the antenna is shared - its a relatively large physical
         | thing. And it can't really be shared except time-shared I
         | believe.
        
           | GekkePrutser wrote:
           | The frequencies are different enough for it to be possible
           | technically. The same way mobile phones can be active on
           | multiple bands at the same time. But indeed the used chipset
           | may not support it.
           | 
           | It's something I would expect Apple to have taken advantage
           | of though, as they own both the hardware and the software.
        
         | cmckn wrote:
         | > Apple's annoying tendency to keep an app running when you
         | close the last window
         | 
         | This is...just how macOS works. Windows applications
         | (generally) tie their lifecycle to the existence of a window,
         | but Macs have a different paradigm: the program can live
         | without any windows. Pretty much every Mac app behaves this
         | way. It's been this way as long as I can remember.
         | 
         | iOS is different; you can force close an app with the app
         | switcher, but the OS generally encourages you to leave things
         | "open" and the OS will periodically wake your process so it can
         | perform various tasks. The OS is very stingy about how much
         | work your process can do when it's in the background in this
         | way. This is one of the challenges when developing for iOS, for
         | sure.
        
           | daveidol wrote:
           | Yeah, I think OP is right that this behavior is confusing
           | _for Windows users_ , but as a longtime macOS user I don't
           | find it confusing or problematic at all.
        
             | GekkePrutser wrote:
             | I'm more a unix user than a Windows user. I use pretty much
             | all current OSes (including Mac and Windows) on a daily
             | basis but FreeBSD is my daily driver. I think macOS is
             | pretty unique in this regard (as well as being the only
             | that use Meta-C / Meta-V for copy/paste, something that
             | still bites me every day as I switch between OSes :) ).
             | 
             | But I only used macOS since 10.2, never used classic.
        
               | saltminer wrote:
               | Classic was the same. On older systems, I think it was a
               | good idea, given the speed of hard drives back then. With
               | SSDs, the performance gains from keeping unused programs
               | alive are far lower, but at the same time, RAM is far
               | more plentiful, so it comes at a much lower cost.
        
               | Ruphin wrote:
               | I had the same issue with copy/paste on MacOS, until I
               | couldn't stand it anymore and used software to remap the
               | keys. I swapped the builtin Fn, Ctrl, and Meta keys
               | around so they are positioned like you'd expect on a
               | normal keyboard (and a normal OS), and it instantly fixed
               | my issues without any other negative side effects aside
               | from having to learn another key combo for Ctrl-C in
               | terminals.
               | 
               | I highly recommend the Karabiner app, it makes this
               | change trivial. There's also a way to do it without
               | additional software, described here:
               | https://apple.stackexchange.com/questions/88897/how-do-
               | you-m...
        
               | GekkePrutser wrote:
               | Thanks, I'll give that a try!
        
               | rswail wrote:
               | Considering Apple added the Command [?] key in _1984_ and
               | the original cut /copy/paste as being command-x/c/v, it's
               | more like the others didn't follow convention at the
               | time.
        
           | GekkePrutser wrote:
           | Not just Windows though. *nix also.
           | 
           | But yes I know it's just how macOS works. I never really got
           | used to it except that it ingrained "Command-Q" into my
           | muscle memory :) I agree it makes sense for some apps. For
           | example for mail, which will continue receiving in the
           | background and notify you. But not for Maps. This is an app
           | that isn't useful when its window is not open.
           | 
           | But I mean this uniqueness to macOS is causing this to cause
           | unintended side-effects. While working in Apple Maps, I
           | imagine the user would not care so much about latency issues
           | and the location tracking would be useful. By the app
           | shouldn't do it while it's not actively being used IMO, as
           | long as there is no way to avoid the latency.
           | 
           | I wonder if the same happens with Apple's own FaceTime by the
           | way, or if they made an exception for that :)
        
       | hamter wrote:
       | it's location services, not apple maps.
        
       | hotfixguru wrote:
       | This have happened since 12.3.1 at the office for me (not at home
       | though). Hope this resolves it.
        
       | kylecordes wrote:
       | I noticed this when using a meeting/streaming tool that detected
       | these bits of latency and went in to a degraded mode, even with
       | abundant bandwidth available.
       | 
       | I tried the various settings for avoiding it, discussed in many
       | other comments here. The only thing that worked for me: get out a
       | USB ethernet adapter and a long wire, don't use WiFi when doing
       | things where it matters.
       | 
       | ... which is ridiculous; I don't want or need location scans at
       | all, I am sitting stationary in my home office.
        
       | daneel_w wrote:
       | A bit of a clickbait-y tweet. Exact same thing happens with any
       | OS and Wi-Fi device when briefly scanning for surrounding access
       | points. In the case of my setup (2017 MacBook Air running
       | 10.15/Catalina) the penalty seems forgettable - avg. ping jumps
       | from 2 ms to 25 ms during 1.5 seconds, on 802.11n/5GHz with about
       | 20 other 2.4GHz/5GHz access points in my vicinity. My Asus
       | ZenBook running Linux Mint and equipped with Intel Centrino Wi-Fi
       | suffers a lot more from the same procedure.
        
         | causi wrote:
         | Why would someone program an OS to do this when it's already
         | connected to an access point? This is like me eating a sandwich
         | and stopping mid-chew every minute to check the fridge.
        
           | amarshall wrote:
           | Reason one is that one doesn't generally connect to an access
           | point (BSSID), but rather to a an SSID. That SSID may have
           | many access points, as the device may roam. Periodic scans
           | check to see if another access point for the same SSID is now
           | a better choice, and switch accordingly. On Linux,
           | configuring the connection to a specific BSSID generally
           | disables periodic scans.
           | 
           | Reason two is to determine location from WiFi network data.
           | Location may not be static even if connected to a single
           | network, since that network may cover a large area and be
           | roam-able, or be moving (hotspot, train, etc.).
        
             | necovek wrote:
             | A moving wifi AP wouldn't really help with establishing a
             | location, since it's, well, non-stationary :)
             | 
             | In theory, it could establish that you are on a
             | bus/train/airplane... and then look up any public transport
             | information for whereabouts of that vehicle, but I don't
             | think anyone does that.
        
             | spookthesunset wrote:
             | > Reason one is that one doesn't generally connect to an
             | access point (BSSID), but rather to a an SSID. That SSID
             | may have many access points, as the device may roam.
             | Periodic scans check to see if another access point for the
             | same SSID is now a better choice, and switch accordingly.
             | 
             | Maybe I don't fully understand the Wi-Fi "space" but I
             | gotta wonder why the standard hasn't embraced a CDMA-like
             | system where your device can just roam around without
             | really caring which AP is the strongest... the access
             | points would all communicate with each other to figure out
             | which one should be responsible for a device.
             | 
             | It would also fix all the nonsense with picking channels
             | for each access point. They'd all use the same spectrum.
             | 
             | But I'm only an armchair observer so who knows...
        
           | sleepybrett wrote:
           | Because on devices with only WIFI the only way to give you
           | 'GPS' like data is to scan for nearby wifi access points.
           | There are several big databases in the sky that know about a
           | great many Access Points and when your laptop says 'i see
           | these 10 APs with this amount of signal' it can figure out
           | where you are.
        
         | outworlder wrote:
         | It's not really forgettable if any app can request a scan at
         | any time - collect wireless logs, then start the Maps app, you
         | will see repeated scans. Locationd doing this ever so often
         | might be acceptable, but not when any app can do this,
         | repeatedly.
         | 
         | Also, 25 milliseconds is about a round trip across half the
         | continental US. Not really sure that's a good tradeoff for
         | devices that are mostly stationary.
        
           | daneel_w wrote:
           | A 750-1000 ms increase would be disturbing, but a 20 ms round
           | trip increase for a brief two seconds is entirely
           | forgettable. It's nothing. It (and more) happens all the time
           | between you and practically any destination out on the
           | Internet as part of normal traffic/congestion patterns.
        
       | lscpike wrote:
       | I discovered this exact problem over lock down 2020. My Teams
       | calls would freeze every 60s.
       | 
       | There's a better solution though! Delete all your saved wifi
       | connections. All those hotels and coffee shops you have connected
       | to in your apple lifetime are the trigger. Reduce them down to
       | those you actually use and the problem goes away.
       | 
       | I'm amazed more people haven't come across this, though from what
       | I've seen people tend to just live with these problems as they
       | don't know where to start in figuring it out.
        
         | [deleted]
        
       | herpderperator wrote:
       | This is normal across all wifi clients; they can't scan for
       | networks and transfer data simultaneously so there will always be
       | increased latency during that event. You can test this yourself
       | by doing a low-interval ping and clicking the wifi icon to show
       | you nearby networks - you'll notice a brief latency spike.
       | 
       | I agree that it's not a good default to have an app doing this,
       | though.
        
         | motrm wrote:
         | This may not always be the case, fortunately! I recall the
         | Broadcom Wi-Fi 7 chipset announcement[0] in April mentioned a
         | dedicated scan core which may well offload the network searches
         | to a separate part of the chip, freeing the AP connectivity
         | core(s) from having to do other tasks for a second or two each
         | minute.
         | 
         | Here's hoping it works as I understand it and other chipsets
         | start doing similar things!
         | 
         | [0] https://news.ycombinator.com/item?id=31060452
        
           | userbinator wrote:
           | To do passive scanning you need to "be quiet" for
           | sufficiently long to pick up beacons from other stations, so
           | that is unlikely to help.
        
             | cmeacham98 wrote:
             | Because wifi is shared via time slicing don't you have to
             | be quiet part of the time anyways?
        
           | dijit wrote:
           | Surely you can't use the same antennae for two different
           | operations at the same time...
           | 
           | The noise would be unsalvageable and you would lose packets,
           | surely.
        
             | carlhjerpe wrote:
             | I mean background scanning only has to be a read operation,
             | shouldn't that make it simpler?
             | 
             | Also things these days often have multiple antennas.
             | 
             | Also for 2.4ghz I believe Bluetooth shares the same
             | channels. I've noticed that my BT headphones reach longer
             | in no-wifi/few wifi locations.
        
             | GekkePrutser wrote:
             | On different bands you can with basic filters. On the same
             | band it would admittedly be tough (unless the band is super
             | wide like the 6E band). It is done by radio repeaters for
             | example but they do need big bulky filters, that kind of
             | thing would not work on a laptop. But it is possible to
             | transmit and receive on the same antenna at the same time,
             | it's not a technical limitation. You just need a good
             | enough filter.
        
           | rasz wrote:
           | Supporting 802.11g means scans are send at 1Mbit. 802.11a
           | bumps it to 6Mb/s, so not much better. This means that every
           | time you want to send a beacon you have a pause equal to the
           | duration it takes to send a packed at 1-6Mbit, not to mention
           | scanning all the channels.
        
         | mmwelt wrote:
         | What helped me was not using a hidden SSID. Apparently, with
         | hidden networks, the computer has to actively probe for the
         | network, but passive probes don't affect latency as much.
        
         | gsich wrote:
         | Passive scans would be possible.
        
         | RicoElectrico wrote:
         | Solution for Windows (replace interface name as needed):
         | netsh wlan set autoconfig enabled=no interface="Wireless
         | Network Connection"
         | 
         | Caveat: you need to turn this back on if you need to re-connect
         | or scan networks.
        
           | causi wrote:
           | Is there a way to configure Windows to only scan for networks
           | when it isn't connected to one?
        
             | wnevets wrote:
             | or change how often it scans
        
           | MauranKilom wrote:
           | Still have two .bat scripts (on/off) on my desktop from a
           | time when I only had wifi. And it still baffles me that such
           | measures can be necessary.
        
             | ncann wrote:
             | I used to have constant ping spike at regular interval and
             | had to do that bat script thing, which fixed it but it was
             | really annoying. Eventually I figured out it was because of
             | a Qt bug in the Qt lib that an application running in the
             | background is using, and there is a system property to
             | disable that behavior.
             | 
             | https://bugreports.qt.io/plugins/servlet/mobile#issue/QTBUG
             | -...
        
           | r1ch wrote:
           | If you have an Intel WiFi card, there's a driver setting
           | "Global BG Scan Blocking" to never scan if you already have a
           | good signal. Works great
        
             | xen2xen1 wrote:
             | I always try to have Intel nics of all kinds, so thanks.
        
         | not2b wrote:
         | But if the laptop is currently connected to a WiFi network with
         | a known location, what's the point of scanning for networks to
         | locate it? You already know that you're within range of a known
         | spot.
        
           | saltminer wrote:
           | Roaming. Although a desktop might not usually be moving while
           | it's on, a laptop user might move around the house,
           | conference room, or lecture hall, and switching APs could
           | result in a stronger signal. It's better to switch before
           | your signal gets weak/drops to minimize disruptions during
           | BSS transitions.
           | 
           | On an unrelated note, in my experience Apple devices are
           | consistently the most frustrating devices when it comes to
           | wifi. They are insanely picky about what networks they will
           | connect to, and they are never consistent.
        
           | bschne wrote:
           | ,,Within range of one network" doesn't give you as much
           | information as ,,all these networks are visible and here's
           | how strong they look from where you are"
        
             | bonestamp2 wrote:
             | True, but is that precision worth the hit to latency...
             | especially if you're trying to do a voice and/or video
             | call? I doubt it's worth the tradeoff most of the time.
        
               | lelandfe wrote:
               | How often are folks in meetings, connected to WiFi, and
               | opening up the WiFi connections list to hunt for other
               | networks?
               | 
               | I'm frankly surprised that the author of these tweets
               | encountered this at all, much less was so annoyed by it
               | as to troubleshoot.
        
               | bonestamp2 wrote:
               | > opening up the WiFi connections list to hunt for other
               | networks?
               | 
               | That's not the trigger. The trigger is location services
               | scanning for networks in the background. So, if you have
               | that enabled then it happens automatically while you're
               | on a call.
        
               | gsich wrote:
               | All the time.
        
             | not2b wrote:
             | Not just within range, connected to. Meaning you're close
             | enough to have a strong signal. If it isn't a strong signal
             | this can be detected and the system could scan in that
             | case, looking for a better one.
        
         | theptip wrote:
         | It's good to know. I suppose the unintuitive part is that
         | "location" means "Wi-Fi scan". Makes sense for a laptop when
         | you think about it but I wouldn't have thought of this as the
         | first thing to check.
        
           | 13of40 wrote:
           | It's kind of a weird situation we're in with this. Facebook
           | and Google track your location by default and you can go back
           | and look where you've been on a map. I used it to figure out
           | the details of an automated traffic ticket I got on a trip to
           | Europe a couple of years back, so it's not totally useless
           | from a consumer perspective, but it's still creepy. So you
           | opt out, but "location services" keeps tracking you and
           | sending your location data (as represented by the SSIDs and
           | signal strength around you) but not telling you you're being
           | tracked. So you opt out of that, and all the sudden you're
           | subject to a bunch of dark patterns insisting you need to
           | enable it again, even though it's perfectly capable of just
           | using the GPS and keeping everything on the client. I'm glad
           | my life isn't interesting enough for it to matter, I guess.
        
           | culturestate wrote:
           | _> the unintuitive part is that "location" means "Wi-Fi
           | scan"_
           | 
           | I was under the impression that this has been SOP for mobile
           | device location forever: get rough location via WiFi and/or
           | tower multilateration while GPS is...I don't know the proper
           | terminology here, _bootstrapping?_ That 's why your dot tends
           | to start somewhere nearby-ish and then quicky jump to your
           | exact location.
           | 
           | It's possible that I'm way off base or my understanding is
           | outdated, though.
        
             | Gigachad wrote:
             | > I don't know the proper terminology here, bootstrapping?
             | 
             | There is the term "Time to first fix" Maybe "getting first
             | fix" could be derived from that.
             | 
             | Wikipedia lists a set of interesting situations with what
             | the device is actually doing that causes the delay
             | https://en.wikipedia.org/wiki/Time_to_first_fix
        
             | carlhjerpe wrote:
             | I'm thinking that my devices could have an offline list of
             | known WiFi mac-addresses from when it's checked GPS before
             | and return those for very accurate results without scanning
             | anything.
        
               | [deleted]
        
       | captainredbeard wrote:
       | Kids, this is why you should randomize when clients check in if
       | your model allows it.
        
       | urda wrote:
       | I cannot replicate this, I believe the twitter use got hooked on
       | a red herring here. To be fair anything anti-apple is a quick way
       | to get clicks.
        
         | mhh__ wrote:
         | Anything apple (both ways) is a good way to get clicks on
         | hackernews at least.
        
           | pessimizer wrote:
           | It's a lot better than it used to be, when every Daring
           | Fireball entry stayed on the front page for days.
        
           | urda wrote:
           | This is also true!
           | 
           | I just can't replicate it, and another user ( leodriesch )
           | pointed out they may be a few versions behind. That's not
           | something I can replicate right now.
        
         | leodriesch wrote:
         | The screenshots are from a version before the Big Sur visual
         | refresh, so at least 2 major versions behind the current
         | release.
         | 
         | Could just be a bug that has been fixed already.
        
           | outworlder wrote:
           | I saw infrequent scans from locationd, every few minutes.
           | Until I opened the Maps app, that is. Then it started
           | triggering frequent scans.
           | 
           | Sure, Maps may want to know your location, but it should not
           | have the ability to constantly poll wifi.
           | 
           | Also, different chipsets may display different behavior.
           | Older wifi chipsets may have more trouble with this.
        
           | urda wrote:
           | I did not realize this / check this. I had made the
           | assumption of latest macOS and-what-have-you.
           | 
           | I however, cannot setup that environment right now.
        
         | urda wrote:
         | Downvotes because another user disagreed with a tweet after
         | they made a fair attempt to reproduce the issue? That's not the
         | spirit of HN.
        
           | Dylan16807 wrote:
           | You got downvotes for being wrong about the issue being real.
           | You get credit for attempting a test but your personal test
           | failed. Oh well. A few downvotes in that case are normal and
           | fine.
        
           | cmeacham98 wrote:
           | Don't play dumb, you're receiving downvotes because you
           | implied OP was lying:
           | 
           | > To be fair anything anti-apple is a quick way to get
           | clicks.
        
         | ActionHank wrote:
         | I've seen this myself, turning off location services solved the
         | issue for me.
         | 
         | It's definitely there and happening.
        
           | chomp wrote:
           | Seconded, this is definitely a thing.
        
             | op00to wrote:
             | Thirded, my game streaming got way better when I turned off
             | location services.
        
       | daverstam wrote:
       | This has been an issue for at least over a year.
       | 
       | Turn off location services and disable the awdl0 interface is the
       | only way (for me) to run lag free zoom calls over wifi with a
       | mac.
       | 
       | https://support.google.com/stadia/answer/9595943?hl=en#zippy...
        
         | alophawen wrote:
         | Please read the article you are commenting on. In it, they
         | identify the cause and lay out a solution. The solution is not
         | to botch your macbook by disabling core components as AWDL
         | (disabling it will break airplay, handoff and other).
        
           | daverstam wrote:
           | Not sure why you assumed I did not read the article. Anyway I
           | just wanted to point out that this has been and still is an
           | issue recognized by Google Stadia and others.
           | 
           | Moonlight project issue discussed in the thread are also
           | recommending to disable awdl to mitigate the issue
           | https://github.com/moonlight-stream/moonlight-qt/issues/159
           | 
           | I never ment to step on any toes, just wanted to raise
           | possible solutions.
        
       | can16358p wrote:
       | I'm on Wi-Fi on my MacBook (Pro 16" 2021). I opened Maps.app
       | (which gets my location correctly), started pinging my router,
       | it's been a few minutes...
       | 
       | No spike. It must be occuring at _some_ corner case, not for
       | everyone.
        
       | rob_c wrote:
       | Great hardware with some crazy choices on top... at least the old
       | intels use 3x antennas
        
       | tonymet wrote:
       | i became obsessed with mtr. your ping latency and variance is a
       | better indicator of vc quality
        
       | tedunangst wrote:
       | I like that the first reply is to switch from zoom to google
       | meet. Very helpful.
        
         | jedisct1 wrote:
         | But no one said "you should rewrite it in Rust" yet.
        
           | carlhjerpe wrote:
           | I reckon that'd be because it isn't relevant to the topic at
           | all. I'd say most things that advertise written in Rust is
           | because it's a valid upside, not all but definitely most.
        
       | nvr219 wrote:
       | I set up automation to prompt me to turn off WiFi when I leave
       | the house.
        
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       (page generated 2022-05-13 23:02 UTC)