I noticed that iOS 7 on my iPad now says this in the Bluetooth pane of the preferences if Bluetooth is turned off: "Location accuracy and nearby services are improved when Bluetooth is turned on."

How does Bluetooth improve location accuracy? I know that Wifi improves accuracy because Apple has various Wifi networks mapped out, but how could Bluetooth help?

  • Pretty sure it's more the latter (nearby services) not the former (location). – Jason Salaz Sep 23 '13 at 7:39
  • @Jason - And what are "nearby services" ? – Nicolas Barbulesco Apr 4 '14 at 14:36
  • I have seen this too, after upgrading from iOS 7 to iOS 7.1. I noticed a disturbing phenomenon : after the upgrade, Bluetooth was turned on, although it was turned off before the upgrade. Is this phenomenon linked to the accuracy benefit of Bluetooth ? – Nicolas Barbulesco Apr 4 '14 at 14:40
  • Nearby services are pieces of hardware that communicate with your phone via Bluetooth. Apparently the Automatic Link is an iBeacon ( blog.automatic.com/every-automatic-road-just-became-ibeacon ). I know of initiatives to replace "audio tour" zone markers with Bluetooth devices because they're standardized. But as far as a practical device that provides location that is a beacon? I don't know first hand. – Jason Salaz Apr 4 '14 at 18:22

iOS 7 introduced support for Bluetooth Low Energy (BLE) iBeacons. These are small Bluetooth devices that can be placed to indicate a very specific location and the system respond in some way when they are detected. Enter a shop and an app for the shop showing you the latest offers might be one way for this to be leveraged. This would be different from usual geolocation APIs which become inaccurate when you are inside large structures (offices, malls etc.) as they cannot get a GPS fix, and WiFi coverage tends to be meshed with repeater stations

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    If this is it then that's not worth the battery drain of leaving Bluetooth on. – asmeurer Sep 23 '13 at 15:44
  • But does this have anything to do with geolocation ? Apple says so, but does not says how. – Nicolas Barbulesco Apr 4 '14 at 14:54
  • Apple would know the exact location of the iBeacon, therefore be able to give you a good idea of where you are. – Collin Anderson Oct 10 '14 at 18:49
  • @Collin - How would Apple know the exact location of the iBeacon ? – Nicolas Barbulesco Jan 20 '15 at 15:13
  • The iBeacon would use other methods, like GPS or WiFi to determine its own location and then probably phone home that info to Apple. – Collin Anderson Jan 20 '15 at 19:07

Let me start with some background info:

WiFi has a signal range (radius) of about 300 feet (outdoors)

If I detect your WiFi you could be anywhere in that 100,000 sqft large area.

Bluetooth has a signal range of 30 feet (outdoors).

So placing your BT in to the Discovery mode and if I can detect your Bluetooth you must be very close :)

Using both signals one can set your location more accurate.

Background: Abstract —Crowd-sourced Wi-Fi-based localization systems uti- lize user input for RF scene analysis and map construction. Such systems reduce the deployment cost and privacy concerns that expert-based site survey systems can create. However, t he main bottleneck of such crowd-sourcing localization systems is a bootstrapping stage, where lack of contributions by users result s in no accuracy guarantee and frequent unnecessary prompting for users’ input, even for explored areas. In this paper, we prop ose a crowd-sourcing localization system that uses both Wi-Fi scene analysis and Bluetooth beacons to address the insufficient con- tribution challenge. After prompting for user input, the mobile device not only submits Wi-Fi fingerprint to a map server, but also enables Bluetooth beacons to disseminate/share its location and fingerprint information to quickly populate the signal map. Then, subsequent user devices entering the area can discover the Bluetooth beacons and are able to instantly obtain room-level location information without causing unnecessary prompting to users. We implement our proposed system in the Linux OS and evaluate the prototype extensively through both experiments and simulation.

Our evaluation results show that using Bluetooth beacons help to improve signal map growth, while maintaining reasonable localization accuracy.

Apple subtly introduced iBeacon as part of iOS 7 at WWDC 2013, though it mentioned the feature only in a single keynote slide and didn't go into detail at all. But this hasn't stopped companies from taking advantage and launching products and services that make use of iBeacon.

iBeacon essentially makes way for new range of apps and functions. With it, stores can pipe coupons to your phone, mapping apps can offer indoor navigation and more. Here's the real clincher: iBeacon might just be that nail in the coffin for NFC.

So finally to answer your question, once upon a time one could go completely anonymous in to the mall and just browse around. Now days everyone will know you are in the mall, more, they will know what store you went in to. How about that for location accuracy.

  • 1
    What's with the downvoting without comments? – M K Sep 23 '13 at 14:16
  • 2
    Revenge, Rage, stupidity, jealousy, you name it. – Ruskes Sep 23 '13 at 14:23
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    I would guess the three down votes were for the first version of this post. If you look at the edit history, it was the outline of an answer. Sadly, there's no mechanism to notify those people of the substantial improvements Buscar has made to this post. In time, it will certainly earn the up votes it deserves. +1 from me – bmike Sep 23 '13 at 16:12
  • What "1000 sqft large area" ? In think there is an error. – Nicolas Barbulesco Jan 20 '15 at 15:21
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    @NicolasBarbulesco : Correct. PI*300*300 is the area of coverage to be more precise. – displayName Apr 12 '15 at 14:18

It's worth noting that since asking this question, iBeacons have gained more traction. Apple now uses them in their stores to give locations specific information on product displays (http://www.zdnet.com/apple-launches-ibeacon-in-254-stores-to-streamline-shopping-experience-7000024026/), and other companies are starting to follow suit.


Apple has various Wifi networks mapped out

Not correct. This was done by Google. Their Street View photographing vehicles had built in WiFi wardriving equipment.

Apple couldn't have done this without physically driving through almost every street on the planet.

  • Apple has its own dataset that is updated constantly by iPhones everywhere. I'm sure Google has one as well. See stackoverflow.com/a/4850274/161801. Note saying something like "was done" is useless here: for such a dataset to be useful, it must be constantly updated. – asmeurer Jun 1 '15 at 16:15

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