Apple's Kevin Lynch Explains Method Behind Apple Watch's Precise Timekeeping

[iMacFarlane]

Well, that's good. I was 60 microseconds late to work the other day and my boss was pissed. Apple Watch to the rescue.

Edit: Wait. Milliseconds? Psshhh. How is that even remotely in the realm of impressive?

 

[grahamtriggs]

Awful lot of ******** to cover the fact that

a) The watch has to sync with a phone anyway

b) Phones have been time syncing to the cell network for ages

c) Everybody's computer (any OS) has been syncing with NTP pretty much since they were connected to the internet.

Fantastic innovation work there Apple. Unless you want us to congratulate you on over-engineering the crystal.

In the meantime, my actual, regular non-smart watch actually uses GPS signals and radio signals from the atomic clock to automatically know where it is, what time zone it's in, and sync to an accurate time. By itself.

And it's solar powered. And it permanently tells the time, it doesn't have to shut off to conserve an insufficient battery life.

Basically, my actual, functional watch is significantly better and smarter than your "smart" watch.

 

[doctor-don]

It's so precise that their digital watch face does not even show seconds (and no way to turn it on)!!!!

If you want to view seconds, why don't you use the stopwatch app?

 

[MH01]

Acter a whole life of too-fast Rolex watches and imprecise digital garbage, I enjoy the Watch perfection a lot.

You found imprecise Quartz watches ?

 

[Quu]

So many people will talk down anything of quality.

Nothing to do with it being quality or not. Every digital computer has a quartz crystal used as a clock and use Network Time Protocol (NTP) servers to get time.

It works like this, every day your computer contacts its assigned NTP server and gets the time within +/- 50ms. The iPhone since the original in 2007 did it. Your Mac in 1999 did it.

It's not special. NTP has been around since 1985. For them to point to this feature and their special quartz clock with its heating element is ridiculous. It's like Ford saying their brand new car has a built in GPS navigation system. Sure not all cars have had those (like not all watches have NTP sync) but it's not revolutionary is it.

All smart watches, smart phones and computers work the same way. Apples watch isn't any more accurate than an Android watch or a Pebble or your iPhone.

 

[ArtOfWarfare]

Doesn't the fact that we have no absolute reference render super-accurate time keeping pointless?

Maybe I'm wrong... relativity is a concept that I still don't really understand, try as I might.

https://en.wikipedia.org/wiki/Special_relativity#Lack_of_an_absolute_reference_frame

 

[BruceEBonus]

Bring on the Watch II. I can hardly wait to sell my old one for a fraction of what I paid and get an even more rewarding timepiece with more ways to tell the time accurate to within a gnat's knacker-whisker. Bring on the Watch III after that and I'll happily cough up the readies again to attain even MORE accuracy than the first two.
What other watch company can boast that level of planned obsolescence-speed, baby? Beat THAT Rolex!

Oh no. What am I sayin'? I've just gawn an forked aht annuver four 'undred nicker for a 'kettle' again wot I keep swappin' every year to do exactly the same job. I didn't even NEED the bleedin' fing in the first place. Cor blimey, guv'nor, I could've just used me old 'kettle' I've 'ad stuffed in the drawer for yonks. Just wait til the 'trouble' finds out. She's gonna kill me!

(Kettle = wrist watch)
This comes from the phrase kettle and hob which rhymed with the word fob or fob watch
(Trouble = wife)
This comes from the phrase Trouble and Strife

 

[naeS1Sean]

So many people will talk down anything of quality.

I don't think thats what they're doing. It's certainly not what I'm doing. We're just not fanboys. (I'm not calling you a fanboy)

1. A person who believes in almost anything that apple says and gives into it's marketing strategy. 2. A prime target for apple marketers to impose their superfluously costing products to.

 

[Loge]

If you want to view seconds, why don't you use the stopwatch app?

The stop watch does not give you the current time; it counts from zero.

 

[69Mustang]

If you want to view seconds, why don't you use the stopwatch app?

You didn't think this through did you?

 

[SlipperySlop]

Am I the only one that doesn't care about time accuracy that much? My non smart watch is about 1 minute out and I dont see why I need to change it - yes it be on time but 1 minute either side isn't going to make a difference - you dont tell people the time is exactly 3.03pm but you say 3.05 or 3.00 or just past...

This post is a joke, right? I would never insult anyone who asks me for the time my assuming they don't want accuracy. The extremes to which the apple watch haters will go to put down the watch never fails to amaze me. But this one might just take the cake.

 

[zorinlynx]

I'm highly amused by this story. When iOS 9 came out my iPhone's clock was off by up to a minute from the correct time. They didn't fix this problem until a point release a couple weeks later.

This was a common problem; Google "iphone ios 9 incorrect time". It's amazing how that actually got out into the release version.

 

[DUCKofD3ATH]

One of the Apple Watch features Apple often highlights is the device's precise timekeeping, which Apple says is within 50 milliseconds of the global time standard. Apple's VP of Technology, Kevin Lynch, today spoke with Mashable and The Telegraph to share some details on how Apple achieves that level of accuracy.

Lynch told Mashable that the Apple Watch is so accurate that the hands of two Apple Watches placed next to one another will move in perfect unison. This is achieved primarily through 15 Network Time Protocol (NTP) servers that Apple has around the world, kept inside of buildings with GPS antennas that connect to GPS satellites broadcasting time data from the U.S. Naval Observatory in Washington, D.C. The Observatory houses an ultra accurate atomic clock, which uses electronic transition frequency to measure time.

Apple's time servers communicate the time to iPhones across the world, and the iPhone in turn syncs with the Apple Watch via Bluetooth to provide the exact time. Communicating a GPS signal from a server to an iPhone to an Apple Watch over Bluetooth has its own delays, which Apple corrects for via software. Apple's NTP servers make sure iPhones and Apple Watches keep time at "Stratum One" accuracy, within milliseconds of "Stratum Zero" devices.

Speaking to The Telegraph, Lynch also described the hardware inside of the Apple Watch that makes sure the time remains accurate. Each Apple Watch has a temperature-controlled crystal oscillator inside to combat time drift that clocks and watches see. The oscillator also makes sure the Apple Watch remains warm enough to keep accurate time in very cold climates. Thanks to this hardware, the Apple Watch is even more accurate than the iPhone.With New Year's Eve approaching, Lynch says Apple Watch owners will have the most accurate watches in the room. "If you're in a room on New Year's Eve wearing one, you will be the best reference for when the New Year actually begins," he said.

Article Link: Apple's Kevin Lynch Explains Method Behind Apple Watch's Precise Timekeeping

So the 50-millisecond delay is due to the speed of light being such a slacker.

 

[Iphtashu Fitz]

Correct me if I'm wrong, but I think it is incorrect to say that Apple has 15 NTP servers. Those are military NTP servers and Apple is merely reading the time on GPS signals that are originated by the military NTP servers. Unless Apple is now in charge of the military's GPS system and satellites and controls what is being transmitted.

You're wrong. As the article clearly states:

This is achieved primarily through 15 Network Time Protocol (NTP) servers that Apple has around the world, kept inside of buildings with GPS antennas that connect to GPS satellites broadcasting time data from the U.S. Naval Observatory in Washington, D.C. The Observatory houses an ultra accurate atomic clock, which uses electronic transition frequency to measure time.

It says they have 15 NTP servers that simply get their timing via GPS, and that the GPS satellites get their timing from the US Naval Observatory. This really isn't terribly impressive, and in fact is rather commonplace. Back in the 1990's I worked for a company that had hundreds of servers located in various datacenters. We had NTP appliances in each datacenter that obtained clock information via GPS (among other sources). Lots of companies sell these sorts of appliances, for example this one. They're not that expensive at all. There's no reason at all to think Apple wouldn't have 15 or more of these at various locations.

 

[CarlJ]

Correct me if I'm wrong, but I think it is incorrect to say that Apple has 15 NTP servers. Those are military NTP servers and Apple is merely reading the time on GPS signals that are originated by the military NTP servers. Unless Apple is now in charge of the military's GPS system and satellites and controls what is being transmitted.

Okay, you're wrong. You assertion is based on misunderstanding the difference between a GPS satellite and an NTP server.

GPS (Global Positioning System) is a system that involves a series of satellites in orbit, broadcasting an extraordinarily accurate reference signal. Using this signal, with the appropriate hardware, one can get very accurate location information, and, as a side effect, very accurate time. NTP (Network Time Protocol) is a long-standing network protocol (agreed-upon communication standard) for synchronizing the time between multiple computers, taking into account the time lost to sending the necessary signals between the computers. It gets much more complicated that that*, but the nice part is that the code to implement NTP servers and clients has all long since been written and thoroughly debugged. A lot of the functionality discussed in the article is inherent in the NTP standard and the common implementations of it.

Setting up a surprisingly accurate NTP server is not hard, it takes a computer (you could use a RaspberryPi for well under $100), the NTP server software (freely available and built into UNIX and Linux) and a GPS receiver/antenna to synchronize with a known good source - the GPS satellites (also under $100). I have no doubt that Apple has 15 NTP servers of its own scattered around the world (indeed, the hostname time.apple.com will evaluate to a list of server IP addresses). Of course, they've likely sweated the details to make them as accurate (and robust) as possible.

Your Apple Watch syncs with your iPhone, which syncs with Apple's collection of NTP servers, which sync with the military's GPS satellites (and likely with each other).

*: (Among other things, when NTP servers/clients discover that their notion of the time is slightly off, they don't "reset" to the right time, like you would a clock, instead they temporarily very slightly adjust the length of a second, so that they slowly catch up, or slow down, the amount needed; this sounds like a minor esoteric detail, but turns out to be very important to make sure that the time they hand out is always monotonic and increasing - time never replays a second or skips a second - this is really important with databases and log files and such, to keep things consistent. They also have a lot of code to ensure a pool of connected machines agree on the time, are able to ignore a member of the pool that somehow gets wildly out of sync, etc. Very good error handling. Interesting stuff. I've worked in the past on teams running network services, like nameservers, webservers, and NTP servers.)

 

[Tubamajuba]

So many people will talk down anything of quality.

lol, the whining and bashing in here is hysterical. they talk about cool technology behind their products...then fanboys whine that they don't care about updating tech in their Mac Pro or other products...wah wah wah.

It's the MacRumors way- downplay everything that Apple does right and infinitely magnify their perceived wrongdoings. I suspect a huge portion of users here would be much happier if they simply switched to Android phones and built their own computers.

 

[Mattaaron09]

Apple's Kevin Lynch Explains Method Behind Apple Watch's Precise Timekeeping

hahahahahahahahaha it's a digital watch hahahahahahahaha

marketing at its best.

This just shows a lack of understanding of how digital watches keep time. Just because it's digital doesn't mean a computer magically does everything. The high quality crystal oscillator in the Apple watch is what does it. Just as an example, the clock on your phone is digital but because it doesn't have a crystal oscillator, your phone must update it's time through a mechanism provided by the cellular network. This method's accuracy ranges from 1 to 30 seconds. In case you weren't sure, that's longer than 50ms.

 

[citysnaps]

50ms is not Stratum One accuracy, not by a factor of several ten thousands (over four orders of magnitude)."

Where did anyone claim that it is? You did not accurately read the story and are making incorrect inferences.

 

[macsba]

I wonder what is the accuracy difference between the Apple time servers and the servers listed in the webpage linked below.
http://tf.nist.gov/tf-cgi/servers.cgi

 

[JoeInMilwaukee]

Honestly I could care less if it were a few seconds off but the tech behind keeping it so accurate is cool.

Okay, so care less. (Or did you mean you COULDN'T care less?)

 

[DryHeave]

A round face once you are displaying time in more than a traditional circular clock layout is incredibly limiting. I hoe Apple doubles down on a square screen and just works on making a better looking watch. When it comes to smart watches a circular screen feels like a failure to me.

I don't want a “smart watch.” I want a digital watch with a nice, high-resolution, raster graphics display that is ROUND like a watch should be. I have no interest whatsoever in any smart-watch features. I just want to be able to change the watch faces on occasion and maybe get the weather or take a phone call.

In terms of taking a phone call, I want to be able to place my fingertip against my ear and have the sound vibrations go through my wrist/hand/finger to my ear. (I believe this is existing technology that has already been done before in labs, and would not be difficult for Apple to implement.)

 

[kdarling]

This post is a joke, right? I would never insult anyone who asks me for the time my assuming they don't want accuracy. The extremes to which the apple watch haters will go to put down the watch never fails to amaze me. But this one might just take the cake.

I think you're confusing people who are amused at a company exec blowing PR smoke, with the few who might be device haters.

Apple is infamous for talking about common technology and manufacturing methods as if they were something unique... a PR technique which works because most people are ignorant of such things.

For example, remember all the oohs and aahs when Apple put out those videos showing how the Apple Watch cases are made? Yet many cheap wristwatches are made the same way: press metal to improve its strength, roll it into strips, stamp out case blanks, use robots to shape and drill them, then cheap labor or robots to polish them.

Personally, I think more people should watch those "How It's Made" episodes on the Discovery channel, so they can recognize this stuff. Like when Jon Ive smoothly drones on about the "extraordinary" way that round Mac cases are made, a more informed viewer can go, "Hey wait that's the same method used to extrude common cooking pots!"

 

[CFreymarc]

""If you're in a room on New Year's Eve wearing one, you will be the best reference for when the New Year actually begins,"

I guess he's never heard of atomic timekeeping thats been around on g shocks for the last ten years, and g-shocks have GPS waveceptors that has also been around..

I keep on wondering why the Apple Watch does not have this. About the only reason I can think of is that they didn't want to use the real estate for GPS when they had Bluetooth and pairing to an iPhone. If the Watch is not connected to an iPhone, wonder how much the clock would drift ...

iPhone has GPS chipset in it. Can't it just use the GPS to update its time? Using time from the GPS would give you precise time in hundreds of nano seconds scale.

You sure about this? None of the tear-downs I have seen claims a GPS antenna.

 

[addicted44]

I'd be more impressed if Apple didn't screw up my alarm multiple times during time zone shifts.

 

[CFreymarc]

I don't want a “smart watch.” I want a digital watch with a nice, high-resolution, raster graphics display that is ROUND like a watch should be. I have no interest whatsoever in any smart-watch features. I just want to be able to change the watch faces on occasion and maybe get the weather or take a phone call.

In terms of taking a phone call, I want to be able to place my fingertip against my ear and have the sound vibrations go through my wrist/hand/finger to my ear. (I believe this is existing technology that has already been done before in labs, and would not be difficult for Apple to implement.)

It is called the Pebble Round. You'll love it.