Further investigation revealed that the BLE device at hand was not detected on iOS 16.6. Was there a change in the recent iOS update that prevented BLE devices from being detected in the background?

From research, I was able to make a BT connection between iPhone12 (iOS 16.6) and iPhone8 (iOS 13.7) in background state. So it seems that there was no limitation of BT scanning in the background. However, I am not able to connect with the BT device I have in my hand in bag ground. With iOS 16.0.3 I can connect in the background. So was there any change in the background BLE communication method between iOS16.0.3~iOS16.6?

Have you set scanOptions? let UUIDs: [CBUUID] = [systemServiceUUID] let scanOptions = [CBCentralManagerScanOptionAllowDuplicatesKey: true] centralManager.scanForPeripherals(withServices: UUIDs, options: scanOptions) But even if you set it, I don't think iOS will allow you to connect permanently like Android does, just for a longer connection time. Please give up on the idea of a completely permanent connection.

Sorry, I solved it myself. This ensures that the scan is performed. let UUIDs: [CBUUID] = [systemServiceUUID] let scanOptions = [CBCentralManagerScanOptionAllowDuplicatesKey: true] centralManager.scanForPeripherals(withServices: UUIDs, options: scanOptions)

I have researched this extensively as well. iOS has a HCE (Host Card Emulation) feature. The proof is in the HCE function in Wallet to realize a virtual transportation The proof is in the fact that Wallet uses HCE to realize a virtual transportation IC card. However, Apple keeps this HCE feature secret so that other developers cannot use it. I think Apple is afraid that the HCE function will be abused. Especially since the HCE feature is related to money and keys. Android, on the other hand, is designed to be highly flexible, so the HCE feature can be used as shown in the video. If you want to create a system or app that uses HCE, you need to create an app for Android or wait until Apple changes its mind. One exception is a system that uses the iPhone as a car key. That is a world-class company like BMW, so they got permission from Apple to make it happen. Developers working for ordinary companies have to give up. As a backdoor technique, it may be possible to have the user register a credit card or transportation IC card in the wallet of his/her iPhone and use a wallet-compatible NFC reader such as the VTAP100 to authenticate the user. Developers who want to use the HCE function to display tickets and coupons in their own apps could place a link to the wallet's pass in the app.