While the screen is on: Background Tags and Apple NFC Evolution

Background NFC tags work when the iPhone screen is on

NFC background tag support that allows users to scan NFC tags without an app arrived with A12 Bionic iPhone XS/XR and iOS 12, but the feature is only becoming truly useful with the enhanced NFC tag support in iOS 13 Core NFC. The Japanese and UK governments have already announced ID card NFC tag support for iOS 13, Jennifer Bailey previewed a new NFC tag Apple Pay feature in May, and the iOS 13 Shortcuts app lets users deploy NFC tags to create their own HomeKit automations. These are exciting developments that are just the start of new powerful and innovative NFC services on the Apple platform.

Apple’s strong point is the tight integration of software services across different devices that no other platform can match. Apple Pay Suica works on iPhone and Apple Watch, but the latter combination of technology, function and size makes it a completely different and beguiling experience. Apple Pay on Apple Watch is its own special thing.

A Temporary Split in the NFC Evolution Line?
The evolution of Apple NFC on both iPhone and Apple Watch was in lockstep up until the arrival of A12 Bionic in 2018. The A12 Bionic NFC powered background tag and Express Transit power reserve features only work on iPhone XS/XR. Apple Watch Series 4 does not support these NFC features, nor does watchOS support the Core NFC framework, this means that NFC tag Apple Pay on Apple Watch is out of the question.

Is the feature split temporary or does it represent a different line of NFC evolution for Apple Watch? The absence of Core NFC makes sense because watchOS does not support 3rd party apps, at least not yet. Express Transit power reserve however, would be a great feature to have on Apple Watch as iOS 13/watchOS 6 Apple Pay Express Transit rolls out to Chicago Ventra, Brisbane myki and Hong Kong Octopus.

Getting that feature on Apple Watch depends on how quickly Johny Srouji’s A team can implement the A12 Bionic Secure Enclave design that handles basic Apple Pay transactions directly and bypasses the OS, on the S Series chip. I cannot believe they are not pushing hard to deliver the goods as soon as possible, perhaps even with Apple Watch Series 5 featuring a S5 Bionic chip.

Delivering a S5 Bionic would get Express Transit power reserve on Apple Watch with NFC performance gains as well. It would also give Apple the option to add NFC background tag reading later on as watchOS becomes more powerful and independent.

The iPhone 7 FeliCa Question
There is one fuzzy area of iOS 13 Core NFC and it is iPhone 7 FeliCa support. At WWDC19 Apple announced that all devices, iPhone 7 and above, would support the enhanced NFC tag lineup: NDEF, FeliCa, MIFARE, ISO 7816, ISO 15693, VAS. But this does not match up with Apple’s own device specs for adding a FeliCa Suica card to Apple Pay:

Apple is telling developers that all iPhone 7 models are good for FeliCa but telling customers that only iPhone 7 JP models are good for FeliCa. This means we get one of two scenarios:

  • iOS 13 retroactively adds FeliCa support to all non-JP iPhone 7 models. Apple can do this by adding device specific FeliCa keys as iPhone 7 NFC hardware is the same for all models worldwide.
  • iOS 13 Core NFC FeliCa tags work but non-JP iPhone 7 models (without FeliCa keys) do not work for FeliCa transactions at the terminal.

The latter ‘FeliCa keys vs. No FeliCa keys’ scenario is illustrated in a comment post by Reddit user FelicaDude, if I understand correctly, that without device specific FeliCa keys iPhone 7 only works in basic Read/Write mode without encryption, with FeliCa keys iPhone 7 works in Read/Write encryption mode necessary for local offline processing with payment terminals (i.e. Suica):

The international iPhone 7s can do basic FeliCa read/write without encryption, because they embed a FeliCa-capable CLF <contactless frontend>. Apple has chosen not to provision them with Osaifu-Keitai keys, probably to avoid paying royalties to FeliCa Networks for each device.

FelicaDude Reddit

The initial iOS 13 beta 3 release build (17A5522f) did not support iPhone 7 but the revised build (17A5522g) released yesterday does. I am intrigued that something is going on with iOS 13 and iPhone 7. It’s probably a vain hope that it could be connected with the upcoming Apple Pay Octopus transit card launch which requires a FeliCa capable device, though it does makes sense for Apple to launch the Apple Pay Octopus with a wide footprint of supported devices. Let’s keep fingers crossed that iOS 13 adds full FeliCa support to all iPhone 7 models and transforms them to the global FeliCa iPhone devices they deserve to be.

UPDATE
FeliCa Dude has answered and posted the definitive take of iPhone 7 FeliCa support for all things from Octopus to iOS 13 Core NFC. We own him thanks for taking the time to cover all the angles in such detail.