Documents passing through the FCC have indicated that Tesla is looking at ultra wideband (UWB) technology, with the company declaring in the filing that it is to "provide a distance estimate" before going on to say this would be "immune to relay attacks."

It's unusual that an FCC filing contains this much information, but it seems that Tesla's intentions are clear, adding UWB to provide more accurate distance readings so that compatible devices are more secure when it comes to keyless entry - or passive entry as Tesla calls it.

The filing also includes a sketch of a Tesla keyfob, suggesting that its own keys will incorporate the tech, as well as the vehicles.

Keyless entry isn't a new thing and its not new to Tesla, but there have been developments over the past few years that change the state of play with this convenience feature.

In recent years there's been the move to support UWB as a more secure system for unlocking. The advantage that it offers - as outlined by Tesla - is that it's much more accurate for proximity detection, so it won't unlock too soon and it will avoid those relay attacks that have seen cars being stolen (or unlocked) without the key actually being present.

Relay attacks are when someone - usually a pair of thieves - uses hardware to detect the transmission frequency used by a wireless key and "relays" that to the car. That might mean that your key, in your house, is used to unlock your car on the drive. It's a common method for motor vehicle theft.

Currently, on a car like the Tesla Model 3, you can buy a keyfob, you can use the NFC card or the Tesla app on your phone, via Bluetooth - which is the entry method that most probably use.

Adding UWB will provide greater security for cars for added peace of mind. But it's also a technology standard that's being used for digital carkeys elsewhere.

UWB for digital keys is supported by Apple and Samsung, for example, meaning that you could, potentially, have your Tesla key integrated into those phones, with Apple Wallet offering to store your carkey. That's currently only supported by BMW's most recent models, but it likely to see huge uptake in coming years.

Whether you'd choose to use Apple CarKey for your digital key rather than the Tesla app is questionable, as the Tesla app contains a lot more than just the key - but it's likely that Tesla's aim will be to use UWB on those devices for the greater security it offers.

The extension could be that devices like the Apple Watch - the most recent of which also supports UWB - could potentially be used to unlock your car too.

Of course, this all comes from an FCC filing and we have no idea if or when it might actually appear in a new Tesla model.