Apple has filed a patent for a system that would allow device owners without their own network connection to backup their files by piggybacking on friends' devices that do.
Apple detailed the system in its application to the US Patents and Trademarks Office, 'Secure Ad Hoc Data Backup to Nearby Friend Devices'. It's essentially a peer-to-peer backup system, which could be used to save critical data on an iPhone, iPad, or wearable device when it lacks its own internet connection.
The 'ad hoc network' refers to the potential for a set of mobile devices that are joined via NFC, wi-fi, or Bluetooth to form their own mobile network which can operate to save important files from a device that momentarily can't connect to a cloud backup service like iCloud.
"In many situations, the user of a mobile device in the ad hoc network may be collecting data (eg, photos, notes) at a time where there is no connectivity with a data backup server. If the mobile device is damaged, lost or stolen during this period of no connectivity, the data may be lost," Apple explains of its purpose.
Of course, it wouldn't be wise to share important files with strangers who probably wouldn't appreciate others consuming their device's scarce storage: Apple envisages something akin to AirDrop, where a device scans for a friend's device in the area and sends a request for them to participate in the backup.
A clever part of the system would only allow a friendly device to participate if it met one or more criterion, such as whether it has enough storage space, sufficient bandwidth, and battery charge. The system would also ensure the backup data being transmitted is encrypted and has a timestamp. The backed-up data would automatically be purged from the friend's device after a set time and also after the backup is sent to a network-based storage system.
Needless to say, this is just a patent and there's no way of knowing whether Apple will eventually decide to make this a feature of the Watch, handheld iOS devices, or Macs.