Hi Core Bluetooth team, I’m seeking official clarification on iOS system-level BLE connection management policy, specifically regarding idle timeouts. Question: When iOS disconnects a BLE peripheral with the error: "The connection has timed out unexpectedly." Is this timeout enforced: Per peripheral (each connection has its own idle timer), or Per app / per Bluetooth radio session (one idle timer for all BLE connections in the app)? In other words: Does a single GATT operation (e.g., a write or notification) on any one peripheral reset the idle timeout for all other BLE connections in the same app? Context (General, No App Code): This is about system behavior, not a bug in any specific app. Applies to foreground and bluetooth-central background mode. No state restoration involved. iOS 17–18, all modern devices. Why This Matters: If per-app, one keep-alive can protect multiple peripherals → simplifies design. If per-peripheral, each connection needs independent activity → higher power use. Reference: Core Bluetooth docs recommend “regular GATT operations” but don’t specify scope. WWDC sessions mention “shared Bluetooth radio” but not timeout granularity. Official Answer Requested: Is the BLE idle timeout per peripheral or per app/radio session in iOS? Thank you for the authoritative guidance.

I’m on macOS, and when my test app sends BLE advertisements, the advertising packet includes the local name and UUID. If my data exceeds 31 bytes, according to the official documentation, the local name should be moved to the scan response. However, on macOS the local name gets dropped, while on iOS sending the same packet places the local name in the scan response. During macOS testing, the app is in the foreground, and the OS version is macOS 26. Is this behavior expected, and how can I prevent the local name from being discarded?

Hi, I'm working on an app that integrates third-party UWB accessories using the Nearby Interaction framework. I want to display real-time data via Live Activities, and ideally, I hope the app can continue ranging/interacting with the accessory even when it's in the background—triggering updates in the Live Activity. Specifically: Can I use Live Activity to keep Nearby Interaction sessions running in the background, as long as the accessory is still nearby and connected? Or do I always need to initiate sessions in the foreground? Are there ways to maintain or trigger new Nearby Interaction sessions entirely in the background, when using third-party UWB accessories? Is there any official guidance regarding permissions, user authorization requirements, or restrictions for background ranging with third-party hardware? Are there recommended strategies or patterns for updating Live Activity widgets with data from Nearby Interaction or UWB accessories while backgrounded? (e.g. Bluetooth triggers, push notifications, background tasks) Any advice, experiences, or official recommendations would be greatly appreciated! I want to ensure my implementation is compliant and offers the best possible user experience. Thanks!

Hello Apple engineering team, We are encountering a BLE connection issue on iPhone 17 series devices running iOS 26.x, while using CoreBluetooth to connect to our Bluetooth accessory in our app Aroma-Link. The problem does not occur on previous iPhone models or earlier iOS versions. Issue Summary Our BLE device uses a specific chipset batch where the 2M PHY capability is not fully supported. The expected behavior (as observed on iPhone 16 / 15 / older models) is: Connection starts on 1M PHY System attempts to upgrade to 2M PHY If 2M PHY upgrade fails → system should fallback and continue using 1M PHY Connection remains active However, on iPhone 17 series: After the system attempts to switch from 1M to 2M PHY and the upgrade fails The device disconnects immediately No fallback to the original 1M PHY occurs This results in an unintended and user-visible disconnection. Reproduction Steps Use an iPhone 17 series device running iOS 26.x Connect to the target BLE peripheral via CoreBluetooth (centralManager connectPeripheral) The system Bluetooth stack initiates a PHY upgrade from 1M → 2M The peripheral rejects / fails the PHY update The connection is disconnected automatically Observed Result centralManager:didDisconnectPeripheral:error: is triggered immediately after the PHY update fails. Expected Result The connection should remain active on 1M PHY, consistent with behavior on: iPhone 16 / 15 / 14 / etc. Earlier iOS versions Impact This causes: Connection instability specifically on iPhone 17 users Inconsistent BLE behavior across device models Unexpected disconnection despite valid 1M PHY link capability Environment Item Details App Aroma-Link Bluetooth Framework CoreBluetooth Devices Affected iPhone 17 series iOS Versions iOS 26.x Reproducibility 100% BLE Peripheral Chipset Specific batch with known 2M PHY limitation Request Could Apple confirm whether the PHY fallback behavior has changed on the iPhone 17 BLE stack, and whether this is an intended change or a regression? We are happy to provide: iOS sysdiagnose logs HCI sniffer captures Peripheral firmware logs Please advise on the recommended next steps for debugging or mitigation. Thank you.

I’m on macOS, and when my test app sends BLE advertisements, the advertising packet includes the local name and UUID. If my data exceeds 31 bytes, according to the official documentation, the local name should be moved to the scan response. However, on macOS the local name gets dropped, while on iOS sending the same packet places the local name in the scan response. During macOS testing, the app is in the foreground, and the OS version is macOS 26. Is this behavior expected, and how can I prevent the local name from being discarded?

Hello Apple engineering team, We are encountering a BLE connection issue on iPhone 17 series devices running iOS 26.x, while using CoreBluetooth to connect to our Bluetooth accessory in our app Aroma-Link. The problem does not occur on previous iPhone models or earlier iOS versions. Issue Summary Our BLE device uses a specific chipset batch where the 2M PHY capability is not fully supported. The expected behavior (as observed on iPhone 16 / 15 / older models) is: Connection starts on 1M PHY System attempts to upgrade to 2M PHY If 2M PHY upgrade fails → system should fallback and continue using 1M PHY Connection remains active However, on iPhone 17 series: After the system attempts to switch from 1M to 2M PHY and the upgrade fails The device disconnects immediately No fallback to the original 1M PHY occurs This results in an unintended and user-visible disconnection. Reproduction Steps Use an iPhone 17 series device running iOS 26.x Connect to the target BLE peripheral via CoreBluetooth (centralManager connectPeripheral) The system Bluetooth stack initiates a PHY upgrade from 1M → 2M The peripheral rejects / fails the PHY update The connection is disconnected automatically Observed Result centralManager:didDisconnectPeripheral:error: is triggered immediately after the PHY update fails. Expected Result The connection should remain active on 1M PHY, consistent with behavior on: iPhone 16 / 15 / 14 / etc. Earlier iOS versions Impact This causes: Connection instability specifically on iPhone 17 users Inconsistent BLE behavior across device models Unexpected disconnection despite valid 1M PHY link capability Environment Item Details App Aroma-Link Bluetooth Framework CoreBluetooth Devices Affected iPhone 17 series iOS Versions iOS 26.x Reproducibility 100% BLE Peripheral Chipset Specific batch with known 2M PHY limitation Request Could Apple confirm whether the PHY fallback behavior has changed on the iPhone 17 BLE stack, and whether this is an intended change or a regression? We are happy to provide: iOS sysdiagnose logs HCI sniffer captures Peripheral firmware logs Please advise on the recommended next steps for debugging or mitigation. Thank you.

the app crashes about 10 seconds after it goes into the background libsystem_kernel.dylib semaphore_wait_trap 100% 45 dyld start + 7116 [0x1825fa000] 100% 44 xxxx main + 76 (main.m:38) [0x104c14000] 100% 43 UIKitCore UIApplicationMain + 336 [0x18ae57000] 100% 42 UIKitCore -[UIApplication _run] + 792 [0x18ae57000] 100% 41 GraphicsServices GSEventRunModal + 120 [0x224975000] 100% 40 CoreFoundation _CFRunLoopRunSpecificWithOptions + 532 [0x185569000] 100% 39 CoreFoundation __CFRunLoopRun + 820 [0x185569000] 100% 38 CoreFoundation __CFRunLoopDoSources0 + 232 [0x185569000] 100% 37 CoreFoundation __CFRunLoopDoSource0 + 172 [0x185569000] 100% 36 CoreFoundation __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28 [0x185569000] 100% 35 BoardServices BSServiceMainRunLoopSourceHandler + 224 [0x19c8b0000] 100% 34 BoardServices __BSSERVICEMAINRUNLOOPQUEUE_IS_CALLING_OUT_TO_A_BLOCK__ + 52 [0x19c8b0000] 100% 33 libdispatch.dylib _dispatch_block_invoke_direct + 284 [0x1bcf40000] 100% 32 libdispatch.dylib _dispatch_client_callout + 16 [0x1bcf40000] 100% 31 FrontBoardServices -[FBSWorkspace _calloutQueue_executeCalloutFromSource:withBlock:] + 168 [0x1a4d45000] 100% 30 FrontBoardServices __94-[FBSWorkspaceScenesClient _queue_updateScene:withSettings:diff:transitionContext:completion:]_block_invoke_2 + 96 [0x1a4d45000] 100% 29 FrontBoardServices __94-[FBSWorkspaceScenesClient _queue_updateScene:withSettings:diff:transitionContext:completion:]_block_invoke_2.cold.1 + 352 [0x1a4d45000] 100% 28 FrontBoardServices -[FBSScene updater:didUpdateSettings:withDiff:transitionContext:completion:] + 708 [0x1a4d45000] 100% 27 FrontBoardServices -[FBSScene _callOutQueue_maybeCoalesceClientSettingsUpdates:] + 128 [0x1a4d45000] 100% 26 FrontBoardServices __76-[FBSScene updater:didUpdateSettings:withDiff:transitionContext:completion:]_block_invoke.129 + 380 [0x1a4d45000] 100% 25 UIKitCore -[UIApplicationSceneClientAgent scene:handleEvent:withCompletion:] + 336 [0x18ae57000] 100% 24 UIKitCore -[UIScene scene:didUpdateWithDiff:transitionContext:completion:] + 244 [0x18ae57000] 100% 23 UIKitCore -[UIScene _emitSceneSettingsUpdateResponseForCompletion:afterSceneUpdateWork:] + 208 [0x18ae57000] 100% 22 UIKitCore __64-[UIScene scene:didUpdateWithDiff:transitionContext:completion:]_block_invoke.218 + 616 [0x18ae57000] 100% 21 UIKitCore -[_UIWindowSceneFBSSceneTransitionContextDrivenLifecycleSettingsDiffAction _performActionsForUIScene:withUpdatedFBSScene:settingsDiff:fromSettings:transitionContext:lifecycleActionType:] + 316 [0x18ae57000] 100% 20 UIKitCore _UISceneSettingsDiffActionPerformChangesWithTransitionContextAndCompletion + 224 [0x18ae57000] 100% 19 UIKitCore +[BSAnimationSettings(UIKit) tryAnimatingWithSettings:fromCurrentState:actions:completion:] + 736 [0x18ae57000] 100% 18 UIKitCore __186-[_UIWindowSceneFBSSceneTransitionContextDrivenLifecycleSettingsDiffAction _performActionsForUIScene:withUpdatedFBSScene:settingsDiff:fromSettings:transitionContext:lifecycleActionType:]_block_invoke + 148 [0x18ae57000] 100% 17 UIKitCore -[_UISceneLifecycleMultiplexer uiScene:transitionedFromState:withTransitionContext:] + 244 [0x18ae57000] 100% 16 UIKitCore -[_UISceneLifecycleMultiplexer _evalTransitionToSettings:fromSettings:forceExit:withTransitionStore:] + 608 [0x18ae57000] 100% 15 UIKitCore -[_UISceneLifecycleMultiplexer _performBlock:withApplicationOfDeactivationReasons:fromReasons:] + 212 [0x18ae57000] 100% 14 UIKitCore __101-[_UISceneLifecycleMultiplexer _evalTransitionToSettings:fromSettings:forceExit:withTransitionStore:]_block_invoke + 252 [0x18ae57000] 100% 13 UIKitCore _UIScenePerformActionsWithLifecycleActionMask + 112 [0x18ae57000] 100% 12 UIKitCore __101-[_UISceneLifecycleMultiplexer _evalTransitionToSettings:fromSettings:forceExit:withTransitionStore:]_block_invoke_2 + 512 [0x18ae57000] 100% 11 UIKitCore -[UIApplication _applicationDidEnterBackground] + 136 [0x18ae57000] 100% 10 UIKitCore +[UIViewController _performWithoutDeferringTransitionsAllowingAnimation:actions:] + 140 [0x18ae57000] 100% 9 UIKitCore __47-[UIApplication _applicationDidEnterBackground]_block_invoke + 256 [0x18ae57000] 100% 8 Foundation -[NSNotificationCenter postNotificationName:object:userInfo:] + 92 [0x182c3d000] 100% 7 CoreFoundation _CFXNotificationPost + 736 [0x185569000] 100% 6 CoreFoundation _CFXRegistrationPost + 436 [0x185569000] 100% 5 CoreFoundation ___CFXRegistrationPost_block_invoke + 92 [0x185569000] 100% 4 CoreFoundation __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 148 [0x185569000] 100% 3 CoreBluetooth -[CBXpcConnection _sendBarrier] + 188 [0x1c2254000] 100% 2 libdispatch.dylib _dispatch_semaphore_wait_slow + 132 [0x1bcf40000] 100% 1 libdispatch.dylib _dispatch_sema4_wait + 28 [0x1bcf40000] 100% 0 libsystem_kernel.dylib semaphore_wait_trap + 8 [0x22d5b6000]

When I startAdvertising, my localName is long, more than 8 bytes. like @"123456789".    [_peripheralManager startAdvertising:@{             CBAdvertisementDataLocalNameKey: @"123456789",             CBAdvertisementDataServiceUUIDsKey: @[[CBUUID UUIDWithString:@"bbbb14c7-4697-aaaa-b436-d47e3d4ed187"]]             }]; When running on macOS 11.x though localName exceeds 8 bytes. But it can still be scanned. {   kCBAdvDataIsConnectable = 1;   kCBAdvDataLocalName = 123456789;   kCBAdvDataRxPrimaryPHY = 0;   kCBAdvDataRxSecondaryPHY = 0;   kCBAdvDataServiceUUIDs =   (     "BBBB14C7-4697-AAAA-B436-D47E3D4ED187"   );   kCBAdvDataTimestamp = "680712553.800874";   kCBAdvDataTxPowerLevel = 12; } But running after macOS 12.x, if localName exceeds 8 bytes, it will be completely ignored. In the scanned data, localName is empty. {   kCBAdvDataIsConnectable = 1;   kCBAdvDataRxPrimaryPHY = 0;   kCBAdvDataRxSecondaryPHY = 0;   kCBAdvDataServiceUUIDs =   (     "BBBB14C7-4697-AAAA-B436-D47E3D4ED187"   );   kCBAdvDataTimestamp = "680712744.108894";   kCBAdvDataTxPowerLevel = 12; } On macOS11.x, SCAN_RSP is utilized if localName exceeds 8 bytes, while on macOS12.x, SCAN_RSP is always empty. Why are there differences between macOS11.x and macos12.x, is there any documentation? What is the maximum limit for localName? (On macOS 11.x, I verified it was 29 bytes Are there other ways to broadcast longer data? Does anyone know why? This has bothered me for a long time...

I'm developing an App that works with BLE connection based devices. The BLE connection process, which connects well to the iPhone 16 without any problems, has not worked at all since the iPhone 17. Even when using the same iOS26 version, iPhone 17 is the only one having problems. Progress is stuck after frame 124 in the entire snoop below. Please check if it is a known problem or if there is a solution. 123 2025-11-04 02:01:39.262000 0.000000 localhost () 7c:c6:b6:91:10:04 () ATT 12 Sent Exchange MTU Response, Server Rx MTU: 232 124 2025-11-04 02:01:39.265000 0.003000 localhost () 7c:c6:b6:91:10:04 () ATT 16 Sent Read By Group Type Request, GATT Primary Service Declaration, Handles: 0x0001..0xffff

I am using a Raspberry Pi 5 (BLE 5.0) to read sensor data and send it via D-Bus and BlueZ to a Flutter application (flutter_blue_plus) for both iOS and Android. The goal is to display these real-time sensor updates directly on the device. On Android, the data transmission is immediate and the real-time visualization is extremely smooth and fast. However, on iOS, both BLE write and notification commands appear with noticeable latency—not only in real-time displays, but also when comparing ordinary notification feedback between the Raspberry Pi terminal and the iOS app. It seems that iOS buffers several BLE packets internally and then dispatches them in batches, which always introduces an additional delay. Additional setup details: I sample and transmit data every 25ms, sending binary packets of 20 bytes (length shouldn’t be a limiting factor). On the iOS side I am using an iPhone 15 Pro with iOS 18.6.2 (BLE 5.3). The Raspberry Pi (using btmon for logging) confirms after connection setup that the connection interval is fixed at 30ms (and cannot be changed). I have tried sending BLE packets every 30ms so that exactly one packet arrives per interval, but this made no difference—the latency and batch delivery remain. Interestingly, faster transmission rates (e.g. sending every 10ms) make the real-time display look smoother on iOS, but the guaranteed overall system latency does not improve. Also these methods used: write-without-response, using app in release modus (no debugging) Is there anyone familiar with this problem or a potential solution? Or is iOS simply not optimized for true real-time BLE data streaming and visualization? Any pointers, technical insights or workarounds would be greatly appreciated.

hello We found that our app had a lot of crashes on iOS 26. The crash stack showed [CBXpcConnection _sendBarrier]. The following is the crash log: Thread 0 name: com.apple.main-thread (cpu_usage: 0.00%) 1 libsystem_kernel.dylib _semaphore_wait_trap (in libsystem_kernel.dylib) 2 libdispatch.dylib __dispatch_sema4_wait (in libdispatch.dylib) 3 libdispatch.dylib __dispatch_semaphore_wait_slow (in libdispatch.dylib) 4 CoreBluetooth -[CBXpcConnection _sendBarrier] (in CoreBluetooth) 5 CoreFoundation ___CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ (in CoreFoundation) 6 CoreFoundation ____CFXRegistrationPost_block_invoke (in CoreFoundation) 7 CoreFoundation __CFXRegistrationPost (in CoreFoundation) 8 CoreFoundation __CFXNotificationPost (in CoreFoundation) 9 Foundation -[NSNotificationCenter postNotificationName:object:userInfo:] (in Foundation) 10 UIKitCore ___47-[UIApplication _applicationDidEnterBackground]_block_invoke (in UIKitCore) 11 UIKitCore +[UIViewController _performWithoutDeferringTransitionsAllowingAnimation:actions:] (in UIKitCore) 12 UIKitCore -[UIApplication _applicationDidEnterBackground] (in UIKitCore) 13 UIKitCore ___101-[_UISceneLifecycleMultiplexer _evalTransitionToSettings:fromSettings:forceExit:withTransitionStore:]_block_invoke_2 (in UIKitCore) 14 UIKitCore __UIScenePerformActionsWithLifecycleActionMask (in UIKitCore) 15 UIKitCore ___101-[_UISceneLifecycleMultiplexer _evalTransitionToSettings:fromSettings:forceExit:withTransitionStore:]_block_invoke (in UIKitCore) 16 UIKitCore -[_UISceneLifecycleMultiplexer _performBlock:withApplicationOfDeactivationReasons:fromReasons:] (in UIKitCore) 17 UIKitCore -[_UISceneLifecycleMultiplexer _evalTransitionToSettings:fromSettings:forceExit:withTransitionStore:] (in UIKitCore) 18 UIKitCore -[_UISceneLifecycleMultiplexer uiScene:transitionedFromState:withTransitionContext:] (in UIKitCore) 19 UIKitCore ___186-[_UIWindowSceneFBSSceneTransitionContextDrivenLifecycleSettingsDiffAction _performActionsForUIScene:withUpdatedFBSScene:settingsDiff:fromSettings:transitionContext:lifecycleActionType:]_block_invoke (in UIKitCore) 20 UIKitCore +[BSAnimationSettings(UIKit) tryAnimatingWithSettings:fromCurrentState:actions:completion:] (in UIKitCore) 21 UIKitCore __UISceneSettingsDiffActionPerformChangesWithTransitionContextAndCompletion (in UIKitCore) 22 UIKitCore -[_UIWindowSceneFBSSceneTransitionContextDrivenLifecycleSettingsDiffAction _performActionsForUIScene:withUpdatedFBSScene:settingsDiff:fromSettings:transitionContext:lifecycleActionType:] (in UIKitCore) 23 UIKitCore __64-[UIScene scene:didUpdateWithDiff:transitionContext:completion:]_block_invoke.218 (in UIKitCore) 24 UIKitCore -[UIScene _emitSceneSettingsUpdateResponseForCompletion:afterSceneUpdateWork:] (in UIKitCore) 25 UIKitCore -[UIScene scene:didUpdateWithDiff:transitionContext:completion:] (in UIKitCore) 26 UIKitCore -[UIApplicationSceneClientAgent scene:handleEvent:withCompletion:] (in UIKitCore) 27 FrontBoardServices __76-[FBSScene updater:didUpdateSettings:withDiff:transitionContext:completion:]_block_invoke.129 (in FrontBoardServices) 28 FrontBoardServices -[FBSScene _callOutQueue_maybeCoalesceClientSettingsUpdates:] (in FrontBoardServices) 29 FrontBoardServices -[FBSScene updater:didUpdateSettings:withDiff:transitionContext:completion:] (in FrontBoardServices) 30 FrontBoardServices __94-[FBSWorkspaceScenesClient _queue_updateScene:withSettings:diff:transitionContext:completion:]_block_invoke_2.cold.1 (in FrontBoardServices) 31 FrontBoardServices ___94-[FBSWorkspaceScenesClient _queue_updateScene:withSettings:diff:transitionContext:completion:]_block_invoke_2 (in FrontBoardServices) 32 FrontBoardServices -[FBSWorkspace _calloutQueue_executeCalloutFromSource:withBlock:] (in FrontBoardServices) 33 libdispatch.dylib __dispatch_client_callout (in libdispatch.dylib) 34 libdispatch.dylib __dispatch_block_invoke_direct (in libdispatch.dylib) 35 BoardServices ___BSSERVICEMAINRUNLOOPQUEUE_IS_CALLING_OUT_TO_A_BLOCK__ (in BoardServices) 36 BoardServices _BSServiceMainRunLoopSourceHandler (in BoardServices) 37 CoreFoundation ___CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ (in CoreFoundation) 38 CoreFoundation ___CFRunLoopDoSource0 (in CoreFoundation) 39 CoreFoundation ___CFRunLoopDoSources0 (in CoreFoundation) 40 CoreFoundation ___CFRunLoopRun (in CoreFoundation) 41 CoreFoundation __CFRunLoopRunSpecificWithOptions (in CoreFoundation) 42 GraphicsServices _GSEventRunModal (in GraphicsServices) 43 UIKitCore -[UIApplication _run] (in UIKitCore) 44 UIKitCore _UIApplicationMain (in UIKitCore) Thanks

TN 3115 states that apps that do not use AccessorySetupKit will loose the ability to launch into the background to service bluetooth in iOS26. Starting in iOS 26 and iPadOS 26, only apps that use AccessorySetupKit to setup Bluetooth accessories will be relaunched. Is there any more information regarding this? Will it affect any app under iOS26 or only those build against the iOS26 SDK? My app (dev build) is still relaunched, even though I'm running iOS26, so I wonder if there are any more conditions checked.

My team has an app that uses BTLE heavily, and has been doing so successfully, including no issues continuing to receive data in the background and updating things in the app (for recording workouts). We have a BTLE write queue that only tries to write when the CBPeripheral.canSendWriteWithoutResponse property is true, or when we get the notification from the system in peripheralIsReady(toSendWriteWithoutResponse:). This is used as a means to rate limit data transfer, as we transfer files, as well as require that packets always arrive in the correct order due to blob encoding. However, we had a new requirement come in to periodically write data out to a connected peripheral. I noticed that as soon as the app was in the background, despite other delegate callbacks coming in, like didRecieveUpdatedValue:, neither the property canSendWriteWithoutResponse nor the delegate callback were called any longer. This meant our write queue didn't think it had permission to write, and packets would just stack up. The failure to deliver these updates didn't occur immediately after backgrounding, but did within 2-5s of backgrounding. If, when in the background, I ignore the changing of that property, and instead just write the data to the peripheral, it works! Can anyone explain why, despite other CBPeripheral callbacks happening when in the background, this one does not?

When our Bluetooth device is scanned and a connection is initiated through the app on the iPhone 17, the air log shows that the iPhone sends an LL_LENGTH_REQ to execute the Data Length Update Procedure. However, our peripheral does not support the Bluetooth LE Data Length Extension, so it responds with an LL_UNKNOWN_RSP PDU with the UnknownType field set to LL_LENGTH_REQ. After receiving the LL_UNKNOWN_RSP, the iPhone 17 does not proceed with the subsequent Bluetooth LE service discovery process. The connection is maintained until the peripheral actively disconnects. Once the peripheral disconnects and continues broadcasting Bluetooth signals, the iPhone 17 repeatedly tries to connect to the peripheral and executes the aforementioned process, even if the app has been terminated. According to the Bluetooth 4.2 core specification ([Vol. 6] Part B, Section 5.1.9), which can be found here: https://www.bluetooth.com/specifications/specs/core-specification-amended-4-2/, the iPhone should accept the LL_UNKNOWN_RSP and terminate the Data Length Update Procedure after receiving it, proceeding with the subsequent operations using the default minimum parameters. Phenomenon: When the app calls the - (void)connectPeripheral:(CBPeripheral *)peripheral options:(nullable NSDictionary<NSString *, id> *)options method, the connection result callback is never received. After a period of approximately 10 seconds, it fails with a callback, displaying the message: central did fail to connect to peripheral: <TY : 45E4A697-31AE-9B5A-1C38-53D7CA624D8C, Error Domain=CoreBLEErrorDomain Code=400 "(null)">.

Hello, I am working on iOS app acting as a central that connects to a peripheral which triggers bonding on connection. The pairing is successful on the first connection and after resetting the peripheral (and forgetting the device in Bluetooth Settings). It fails, however, after this devices is forgotten in the Bluetooth Settings at DHKey check, but the peripheral remains turned on. The peripheral is a linux device using BlueZ. This issue does not happen with Android device. Steps: Connect with the peripheral in the app using Core Bluetooth for the first time. Accept the pairing prompt. Bonding is successful and the peripheral is under MY DEVICES in Bluetooth Settings. Forget the device in Bluetooth Settings. Connect with the peripheral in the app using Core Bluetooth. Pairing prompt pops up repeatedly. Sometimes it pops up once, but the pairing is not successful as the device is not present under MY DEVICES. Connect with the peripheral in the app using Core Bluetooth another time. Pairing prompt still shows app. Restarting the peripheral fixes it and central iOS device is able to pair again. Sharing a screen shot from nRF Sniffer for SMP packets which indicate DHKey check failing. I was not able to attach whole log files because of size, let me know if needed I can share them in a different way somehow. Is there anything different in the flow between pairing for the first time and after forgetting the device?

FB18383742 Setup 🛠️ Xcode 16.4 (16F6) 📱 iPhone 13 mini (iOS 18.0.1) ⌚️ Apple Watch Series 10 (watchOS 11.3.1) Observations As AccessorySetupKit does not request "Core Bluetooth permissions", when a watchOS companion app is installed after having installed the iOS app, the toggle in the watch settings for Privacy & Security > Bluetooth is turned off and disabled After removing the iPhone associated with the Apple Watch, Bluetooth works as expected in the watchOS app Upon reinstalling the iOS app, there's a toggle for Bluetooth in the iOS ASK app's settings and the ASK picker cannot be presented 🤨 From ASK Documentation: AccessorySetupKit is available for iOS and iPadOS. The accessory’s Bluetooth permission doesn’t sync to a companion watchOS app. But this doesn't address not being able to use Core Bluetooth in a watch companion app at all 🥲 Reproducing the bug Install the iOS + watchOS apps Launch iOS app, tap "start scan", observe devices can be discovered (project is set up to find heart rate monitors) Launch watchOS, tap allow on Bluetooth permission pop-up watchOS app crashes 💥 Meanwhile, in the iOS app, there should be a log entry for 💗 CBCentralManager state: poweredOff and the ASK picker is no longer able to discover any devices The state of the device permissions: iOS app has no paired accessories or Bluetooth permission watchOS app's Bluetooth permission shown as turned off & disabled Remove the iOS app Relaunch the watchOS app Notice the CBCentralManager state is unauthorized Remove and reinstall the watchOS app Tap allow on Bluetooth permission pop-up watchOS app does not crash and CBCentralManager state is poweredOn The state of the watch permissions: Bluetooth is turned on & the toggle is not disabled Note that at this time the iOS app is not installed, there is no way to remove Bluetooth permission for the watch app. Reinstall + launch the iOS app Notice a warning in the log: [##### WARNING #####] App has companion watch app that maybe affected if using CoreBluetooth framework. Please read developer documentation for AccessorySetupKit. Notice a log entry for 💗 CBCentralManager state: poweredOn before tapping start scan Tap start scan and observe another log entry: Failed to show picker due to: The operation couldn’t be completed. (ASErrorDomain error 550.) ASErrorDomain 550: The picker can't be used because the app is in the background. Is this the expected error? 🤔 The state of the iOS permissions: The app's settings show a Bluetooth toggle normally associated with Core Bluetooth, but the app never showed a Core Bluetooth pop-up The iOS ASK app now has Core Bluetooth permission 😵‍💫 Following up with Apple This is a known bug that should be fixed in watchOS 26 when Bluetooth permissions for watch apps can be set independently of the iOS app. I've yet to test it with watchOS 26. See repo for the same post with screenshots of the settings and demo code reproducing the bug: https://github.com/superturboryan/AccessorySetupKit-CoreBluetooth-watchOS-Demo

mac/ios acts as a BLE client. After successfully establishing a BLE connection, it sends large amounts of data to the peer device. After sending data for a period of time, the system does not return peripheralIsReadyToSendWriteWithoutResponse for a long time, causing the data transmission to stall.

I'm experiencing intermittent failures when executing APDU (Application Protocol Data Unit) commands through Core Bluetooth to communicate with external secure elements. The communication flow involves establishing a BLE connection, discovering services and characteristics, and then sending structured APDU commands for card management operations. While the initial connection and characteristic discovery work reliably, I'm encountering inconsistent behavior during APDU command execution where commands either timeout, return unexpected response codes, or fail to complete the expected transaction sequences. The issue appears to be more prevalent when sending multiple APDU commands in rapid succession or when the commands involve cryptographic operations. I've implemented proper error handling and retry mechanisms, but the failures seem to occur at the Core Bluetooth level rather than in my application logic. The peripheral device responds correctly to the same commands when tested with other platforms, suggesting the issue might be related to iOS-specific BLE behavior or timing constraints. I'm using standard Core Bluetooth APIs (CBPeripheral, CBCharacteristic) with proper delegate implementations and have verified that the peripheral remains connected throughout the operation. Has anyone encountered similar issues with APDU command execution over BLE on iOS, and are there any known workarounds or best practices for ensuring reliable command delivery and response handling?

After the macOS Sequoia update, my app seems to have an issue with Bluetooth communication between macOS and iOS that uses CoreBluetooth for Central-Peripheral communication. Setup: The iPhone (in my case: iPhone 14 Pro with iOS 18.0 (22A3354)) acts as the Central, and the Mac (in my case: 14" MacBook Pro 2023 with macOS 15.0 (24A335)) as the Peripheral. I’ve implemented a mechanism where the Central (iPhone) sends a message to the Peripheral (Mac) every 15 seconds to keep the connection alive (Because it needs to wait for notify characteristic updates). I never noticed this kind of issue before, but with macOS Sequoia I get it permanently. Issue: The connection drops unexpectedly after a period of time (sometimes 20 seconds, sometimes a few minutes) with CBErrorDomain - code 6: The connection has timed out unexpectedly. Sample Code: Peripheral (Mac): ContentView (Peripheral).txt ContentViewModel (Peripheral).txt Central (iPhone): ContentView (Central).txt ContentViewModel (Central).txt Reproduce: I attached sample code including the Central-Sample (for iPhone) and Peripheral-Sample (for Mac). Just run the Peripheral-Sample (after granting Bluetooth permissions). Then run the Central-Sample and select the Mac device in the list After selecting it should connect, discover the service & characteristic and should start writing messages to it. After some time the func centralManager(_ central: CBCentralManager, didDisconnectPeripheral peripheral: CBPeripheral, error: (any Error)?) {should get called with timed out unexpectedly error. Could anyone please look into this issue and advise on whether there’s a known bug or any workaround? Any guidance would be greatly appreciated, as this impacts the stability of Bluetooth communication between the devices. Thanks in advance. Logs: I also ran the console.app during this issue which got these errors (if this is helpful): console_logs.txt

I'm developing an application using the accessory setup kit (BLE) on iOS 18+. An important aspect of the connection process is being able to find and choose the correct device. I noticed on iOS 18.2 that I was able to both scroll through the discovered accessories as well as view the advertised name. However, after upgrading to 18.7.2, only a single device is viewable and the advertised name is no longer available. Is there a trigger for this feature that I need to enable or was this "multiple discovery" feature removed? If so, why?