BLE 设备在通过 iOS 上的免提配置文件呼叫时断开连接，原因为 722 步骤系统诊断日志

如何解决BLE 设备在通过 iOS 上的免提配置文件呼叫时断开连接，原因为 722 步骤系统诊断日志

我们开发了自己的 BLE 设备并连接到 iPhone。我们发现通过 HFP 进行并行呼叫时，它会在 2 到 3 分钟后断开连接的问题。（例如：使用汽车音响系统、信息娱乐 HUD 等）。

有谁知道 722 代表什么状态。我们如何解决这个问题？谢谢。

步骤

iPhone 连接到 Our Device（在后台模式下持续收集数据。）
iPhone 连接到 Car Audio Systems
iPhone 使用 IM 应用（通过 HFP）拨打电话。
2 ~ 3 分钟后，iPhone 和Our Device 之间的连接因722 原因断开。

系统诊断日志

default 2021-02-09 17:04:57.813721 +0800    bluetoothd  Server.LE.Connection    LE Link disconnected for handle 0x14c804720 address <private> with reason 722 encryptionPending 0
default 2021-02-09 17:04:57.813774 +0800    bluetoothd  Server.LE.Connection    LE ConnManager disconnection complete reason 722 address=<private> localRole=Master
default 2021-02-09 17:04:57.816296 +0800    bluetoothd  Stack.GATT   _GATT_LE_disconnectedCB on handle 0x000000014C804720 with reason  STATUS 722
default 2021-02-09 17:04:57.816977 +0800    bluetoothd  Server.LE   Device "E2278A91-B7B6-2122-696C-BE887487C8D7" set last connected time to 1612890297
default 2021-02-09 17:04:57.820707 +0800    bluetoothd  Stack.CL     Removing peer ID 0 for handle 0x000000014C804720
default 2021-02-09 17:04:57.820869 +0800    bluetoothd  Stack.HCI    Releasing LE connection 0x0041
default 2021-02-09 17:04:57.822551 +0800    bluetoothd  Server.LE.Connection    Device "E2278A91-B7B6-2122-696C-BE887487C8D7" does not require low latency
default 2021-02-09 17:04:57.822580 +0800    bluetoothd  Server.LE.Connection    Found link-ready device calling disconnection notification
default 2021-02-09 17:04:57.822582 +0800    bluetoothd  Server.LE.Connection    disconnected from device "E2278A91-B7B6-2122-696C-BE887487C8D7" successfully (locally-initiated)
default 2021-02-09 17:04:57.822585 +0800    bluetoothd  Server.LE.Connection    linkReady:1 disconnectDevice:0 localRole:0 reason:722 result:0
default 2021-02-09 17:04:57.824928 +0800    bluetoothd  Server.LE.Security  Removing temporary security keys for device <private>