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Find My iPhone Without GPS or Internet: The Secret of Apple's Global "Locator" Network
You should think that you lost your keys in the forest, and they do not have a battery, and they do not have , and they do not have Internet, but after an hour you find them, and this is what Apple does, because it has learned how to find lost devices like AirPods, and AirTags, and of course find my iPhone by phone number which is not connected to the network or is completely turned off.
Before recently, it was impossible to find a phone without the Internet, but Apple made a special, hidden, global network, and this network works because it uses billions of other Apple devices all over the world.
The Problem: Why Old Finding Methods Do Not Work
The Old Way to Find Things
Before, finding a lost phone worked by a simple rule, which was: "If there is no network, you are not on the map."
GPS and Internet: The phone found its location using satellites and then sent this location to the Apple server using mobile Internet or Wi-Fi.
Server and App: The server saved this location, and when you opened the "Locator" app on your other device, the app asked the server to get this location and show it on the map.
Big "Blind Spots" in the Old System
This old method had three very bad problems, and these problems made the search useless when it was most important:
Phone is Off: If the battery ran out, or if a thief turned off the iPhone on purpose, the GPS chip did not work, and the Wi−Fi part did not work, so the phone was only a piece of glass and metal and could not send a signal, and the search ended at the last place where the phone was working.
No Network: The phone is in the subway or in the forest or in a basement or in a place where there is no mobile service, so the GPS might work, but there is no way to send the location data to the server, and the location stays locked inside the device.
Settings Reset: A bad person can reset the phone settings or delete the data, and although "Activation Lock" protects the phone from being sold again, it does not help you know where the device is right now.
Apple decided that to find a phone without the network, they needed to make a new network that does not need mobile service.
How the Apple "Locator" Network Works: Turning the World into a Finder
The Main Secret: The Bluetooth Low Energy BLE Light
An Off Phone is Not Completely Off: Even when a new iPhone is "off," it is not completely out of power, because it goes into a special very low power mode. In this mode, GPS and Wi−Fi do not work, but the Bluetooth Low Energy BLE chip stays on.
Becoming a Light: The lost or off iPhone starts to work like a "radio light", so every few seconds it sends out a special code that changes often and is random using a Bluetooth signal, and this signal is very weak, it uses little battery, and has no information about the location or the owner.
The Role of a Billion Helpers: Secret Finders
The lost iPhone sends signals, but it cannot send them to the Internet, and this is where other devices start to help:
Found by a Nearby Device: Any other Apple product that is turned on, someone else's iPhone, iPad, or Mac, passes near the lost iPhone.
Scanning by Bluetooth: The helper device, we call it the "Scanner", automatically finds this Bluetooth signal from your lost phone.
Sending Through the Internet: The Scanner, the other person's phone, uses its own working Internet 4G/Wi−Fi to send the data to the Apple server, and it sends the Scanner's location, the place where it found the signal, with the special code-light from your lost phone.
Finding the Owner: The Apple server gets this data, and because it has the special code-light, it can connect this code to your Apple ID.
The Result: Your lost phone does not use its own Internet, but it uses Bluetooth to send a secret code, and it uses someone else's Internet to make sure that this code gets to you.
How It Works Alone
To make the "Locator" network work, Apple uses a special chip called U1 Ultra Wideband, which helps to find the distance to the Bluetooth light very well, and also special parts in the main chip, the A-series processor, that manage the power.
Because of this, the iPhone can keep sending these Bluetooth signals for up to five hours after it is turned off, and it can work even longer when the battery is very low.
Safety and Secrecy: How to Keep the Helpers' Secret
The most important part of this system is trust, because nobody will help find other people's devices if it is not safe for their own privacy, so Apple promises that neither you nor Apple itself nor the owner of the "Scanner" can know anything extra.
Protecting the "Scanner" Owner
The owner of the other iPhone that sent information about your lost phone will know nothing about this process.
Secret Scanning: The work of looking for Bluetooth signals happens automatically in the background, which is normal phone work and does not need extra battery.
Location Is Hidden: The other iPhone sends its location to the server, but Apple uses this location only to connect it to your lost phone, so the owner of the lost phone only sees the location of their device, but they do not know whose phone "found" the signal, because Apple keeps this process secret.
Protecting the Lost Phone
The main secret is how the data is written, because the data that is sent is useless to everyone except you.
Special Keys: Your iPhone does not use the same "secret code" all the time, because it makes hundreds of new, random codes, keys, that change all the time, and only your Apple ID knows a special "main key" that can read these hundreds of codes.
End-to-End Encryption E2EE: When the other iPhone Scanner finds your code and sends it with its location to the Apple server, it does this in a special hidden way, so even Apple cannot read this code.
Only the Owner Sees It: When you go into the "Locator" app on your other device, this device uses your main key, which is tied to your Apple ID, to read the data, and only after that does the dot appear on the map.
Comparison: Think that your phone sends not a letter, but a locked safe, so the other phone Scanner just takes this safe to the bank, to the Apple server, and the postman and the bank workers do not know what is inside the safe, because only you, the owner, have the special key to open it.
How to Use It: How to See an Off Phone
Turning the Feature On
The best part is that you do not need to turn anything on yourself, because this feature is normal for all new iPhones, starting with iOS 13 and especially iOS 15.
Normal Setting: When you set up a new iPhone, the "Locator Network" feature turns on automatically.
Last 24 Hours: If the phone's battery is very low, only a little left, it automatically sends its last location to the server and goes into Bluetooth Light mode so it can be found even when it is completely off.
The Finding Process
When you look for a lost phone in the "Locator" app, Find My:
Normal Search: First, the app looks for the phone using the normal, direct way GPS using Wi−Fi.
Network Starts: If there is no direct way, the phone is off or has no network, the app automatically starts the Search with the "Locator" Network.
Shown on the Map: If someone else's iPhone passed near your off phone, you will see its location, and the dot on the map will show the place where your Bluetooth signal was "found" by the other device.
UWB for Very Exact Finding, AirTag: If you are looking for small things, AirTag, or devices very close to you, new iPhones use the Ultra Wideband UWB chip U1 technology, and this lets you find the thing very exactly, which is good for finding keys under the sofa.
Lost Mode
Turning It On from Far Away: You can turn on "Lost Mode" from far away, even if the phone is not on the network.
Message and Lock: As soon as the phone "finds" another iPhone, gets the signal through the Bluetooth network, it will not only send its location to you, but it will also show the message you wrote on its screen, for example: "This phone is lost. Call number XXXX."
Activation Lock: The phone stays locked for the thief, even if they try to delete the data from it while it is connected to a computer.
Conclusion
The "Locator" network is an example of how billions of devices can work together to make things safer and calmer for the owner, while not losing privacy, so instead of using only one way, GPS and Internet, Apple has turned its whole system into one very big, secret finding machine that works even when the device seems completely dead, and this gives iPhone owners real hope to find their things even in very hard situations.
