CODEWITHSUNDEEP
androidiphoneiosbluetoothheadset
Ram
Ram

Reputation: 1890

How call process works with blue tooth devices?

I tested few things on Android mobiles with bluetooth headset.I have few questions regarding the same.

Device Specifications :

Android 2.3 above Headset Blue tooth profiles : HFP,A2DP

I accepted a call from accept button from the android mobile and I was able to hear the call from the bluetooth headset.After that I moved android device out of range and accepted the call from android and when the android mobile entered bluetooth range bluetooth headset connected automatically.Is it universal, I mean all the bluetooth headsets support the same or are there any deviations?

I would like to know what will happen when we accept the call from headset or Android mobile.Is it something like Android OS is going to create a call session/audio session and transfer this to headset when accept button is pressed from the headset.If a call is already received and when the headset is in bluetooth range,Android mobile is going to route the volume to headset. In both the cases the same thing happens(just routing the audio).I would like to know the call handling in detail both the cases.Could some one help me on this.

How the call process is different in iOS?

Edit

Is any call session like AVAudoioSession is getting created when we accept a call ?

@jjv360:

"An app can manually assign a route even though a bluetooth headset is connected, in which case it's up to the app to handle what happens when a new route is detected..."

Is it possible to route the call session to headset(from microphone to headset sco) in an iOS app?Could you please give some pointers on this.

Upvotes: 1

Views: 763

Answers (1)

jjv360
jjv360

Reputation: 4140

On iOS if you connect a bluetooth headset while an audio session is active the current audio app(s) get notified and by default will transfer the session's route to the headset. An app can manually assign a route even though a bluetooth headset is connected, in which case it's up to the app to handle what happens when a new route is detected...

Also, AFAIK the reconnect is attempted by both the device (for a very short time) and the headsets, so it's mainly up to the headset to attempt reconnecting when it goes out of range. Almost all headsets should do this though.

It doesn't matter which button was used to accept the call (on device or on headset), if the bluetooth headset is connected it will be used, unless an app has specified that it doesn't want to use that route.

The call process AFAIK is the same for Android and iOS.

With the protocol used, A2DP is the high-quality protocol used when listening to music. It supports high-quality audio, but is one-way, so only works if the bluetooth headset is not recording from the mic. HFP is used when recording is also needed, but the quality is less. That is why you will notice on iOS if you're listening to music on bluetooth headset and then start a recording app, the sound quality will become worse until you stop the recording...

Upvotes: 1

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