Bluetooth HF role

Bluetooth HF role

[Mikel Astiz]

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Hi all,

I'm trying to understand the features currently supported by oFono 
regarding the handsfree role in Bluetooth/HFP. My first impression 
looking at the source code is that some HFP functionality might be 
missing, but I would rather have your confirmation.

Some examples I've found so far are the following:
1. Response and hold (AT+BTRH=0)
2. Redial last number (AT+BLDN)
3. Retrieval of supported Bluetooth features for a certain modem/device 
(AT+BRSF)

Could you clarify which (if any) of these features are currently 
supported by oFono?

In general, is there any documented list of unsupported features?

Regards,
Mikel

Re: Bluetooth HF role

[Denis Kenzior]

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Hi Mikel,

On 08/24/2011 10:28 AM, Mikel Astiz wrote:
> Hi all,
> 
> I'm trying to understand the features currently supported by oFono
> regarding the handsfree role in Bluetooth/HFP. My first impression
> looking at the source code is that some HFP functionality might be
> missing, but I would rather have your confirmation.
> 

Correct, in general only features that map 1:1 to existing APIs are
exposed.  So that means network registration, voicecalls and call-volume
interfaces.

> Some examples I've found so far are the following:
> 1. Response and hold (AT+BTRH=0)
> 2. Redial last number (AT+BLDN)
> 3. Retrieval of supported Bluetooth features for a certain modem/device
> (AT+BRSF)
> 

BRSF is supported and used internally, but the information is not
exposed over D-Bus.

> Could you clarify which (if any) of these features are currently
> supported by oFono?

Bluetooth specific features are not supported yet, these will require a
separate atom. Roughly this means anything starting with +B.. including:
	- +BINP
	- +BLDN
	- +BVRA
	- +NREC
	- +BSIR
	- +BTRH

> 
> In general, is there any documented list of unsupported features?
> 

In general the TODO list is your best source of readily available
information.  In the case of HFP HF, there is no such documentation ;)
Patches adding tasks to the TODO list to support these features are
always welcome.

Regards
-Denis

Re: Bluetooth HF role

[Mikel Astiz]

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Hi Denis,

On 08/20/2011 11:00 AM, Denis Kenzior wrote:
> Hi Mikel,
>
> On 08/24/2011 10:28 AM, Mikel Astiz wrote:
>> Hi all,
>>
>> I'm trying to understand the features currently supported by oFono
>> regarding the handsfree role in Bluetooth/HFP. My first impression
>> looking at the source code is that some HFP functionality might be
>> missing, but I would rather have your confirmation.
>>
> Correct, in general only features that map 1:1 to existing APIs are
> exposed.  So that means network registration, voicecalls and call-volume
> interfaces.
>
>> Some examples I've found so far are the following:
>> 1. Response and hold (AT+BTRH=0)
>> 2. Redial last number (AT+BLDN)
>> 3. Retrieval of supported Bluetooth features for a certain modem/device
>> (AT+BRSF)
>>
> BRSF is supported and used internally, but the information is not
> exposed over D-Bus.
>
>> Could you clarify which (if any) of these features are currently
>> supported by oFono?
> Bluetooth specific features are not supported yet, these will require a
> separate atom. Roughly this means anything starting with +B.. including:
> 	- +BINP
> 	- +BLDN
> 	- +BVRA
> 	- +NREC
> 	- +BSIR
> 	- +BTRH
>
>> In general, is there any documented list of unsupported features?
>>
> In general the TODO list is your best source of readily available
> information.  In the case of HFP HF, there is no such documentation ;)
> Patches adding tasks to the TODO list to support these features are
> always welcome.
>
> Regards
> -Denis

OK, thanks for the information.

Then I guess the next question is whether you have plans to support this 
in the future, or if you would accept patches in this direction. I'm 
afraid some of them could potentially affect the existing API.

Best regards,
Mikel

Re: Bluetooth HF role

[Denis Kenzior]

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Hi Mikel,

On 08/25/2011 07:32 AM, Mikel Astiz wrote:
> Hi Denis,
> 
> On 08/20/2011 11:00 AM, Denis Kenzior wrote:
>> Hi Mikel,
>>
>> On 08/24/2011 10:28 AM, Mikel Astiz wrote:
>>> Hi all,
>>>
>>> I'm trying to understand the features currently supported by oFono
>>> regarding the handsfree role in Bluetooth/HFP. My first impression
>>> looking at the source code is that some HFP functionality might be
>>> missing, but I would rather have your confirmation.
>>>
>> Correct, in general only features that map 1:1 to existing APIs are
>> exposed.  So that means network registration, voicecalls and call-volume
>> interfaces.
>>
>>> Some examples I've found so far are the following:
>>> 1. Response and hold (AT+BTRH=0)
>>> 2. Redial last number (AT+BLDN)
>>> 3. Retrieval of supported Bluetooth features for a certain modem/device
>>> (AT+BRSF)
>>>
>> BRSF is supported and used internally, but the information is not
>> exposed over D-Bus.
>>
>>> Could you clarify which (if any) of these features are currently
>>> supported by oFono?
>> Bluetooth specific features are not supported yet, these will require a
>> separate atom. Roughly this means anything starting with +B.. including:
>>     - +BINP
>>     - +BLDN
>>     - +BVRA
>>     - +NREC
>>     - +BSIR
>>     - +BTRH
>>
>>> In general, is there any documented list of unsupported features?
>>>
>> In general the TODO list is your best source of readily available
>> information.  In the case of HFP HF, there is no such documentation ;)
>> Patches adding tasks to the TODO list to support these features are
>> always welcome.
>>
>> Regards
>> -Denis
> 
> OK, thanks for the information.
> 
> Then I guess the next question is whether you have plans to support this
> in the future, or if you would accept patches in this direction. I'm
> afraid some of them could potentially affect the existing API.
> 

Patches are always welcome.  I'm not sure why you want to change the
existing API, sounds like most of these features belong to a new atom
interface, however I could be wrong.  Go ahead and send your proposal so
we have a starting point for the discussion.

Regards,
-Denis

Re: Bluetooth HF role

[Mikel Astiz]

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Hi Denis,

On 08/21/2011 04:13 AM, Denis Kenzior wrote:
> Hi Mikel,
>
> On 08/25/2011 07:32 AM, Mikel Astiz wrote:
>> Hi Denis,
>>
>> On 08/20/2011 11:00 AM, Denis Kenzior wrote:
>>> Hi Mikel,
>>>
>>> On 08/24/2011 10:28 AM, Mikel Astiz wrote:
>>>> Hi all,
>>>>
>>>> I'm trying to understand the features currently supported by oFono
>>>> regarding the handsfree role in Bluetooth/HFP. My first impression
>>>> looking at the source code is that some HFP functionality might be
>>>> missing, but I would rather have your confirmation.
>>>>
>>> Correct, in general only features that map 1:1 to existing APIs are
>>> exposed.  So that means network registration, voicecalls and call-volume
>>> interfaces.
>>>
>>>> Some examples I've found so far are the following:
>>>> 1. Response and hold (AT+BTRH=0)
>>>> 2. Redial last number (AT+BLDN)
>>>> 3. Retrieval of supported Bluetooth features for a certain modem/device
>>>> (AT+BRSF)
>>>>
>>> BRSF is supported and used internally, but the information is not
>>> exposed over D-Bus.
>>>
>>>> Could you clarify which (if any) of these features are currently
>>>> supported by oFono?
>>> Bluetooth specific features are not supported yet, these will require a
>>> separate atom. Roughly this means anything starting with +B.. including:
>>>      - +BINP
>>>      - +BLDN
>>>      - +BVRA
>>>      - +NREC
>>>      - +BSIR
>>>      - +BTRH
>>>
>>>> In general, is there any documented list of unsupported features?
>>>>
>>> In general the TODO list is your best source of readily available
>>> information.  In the case of HFP HF, there is no such documentation ;)
>>> Patches adding tasks to the TODO list to support these features are
>>> always welcome.
>>>
>>> Regards
>>> -Denis
>> OK, thanks for the information.
>>
>> Then I guess the next question is whether you have plans to support this
>> in the future, or if you would accept patches in this direction. I'm
>> afraid some of them could potentially affect the existing API.
>>
> Patches are always welcome.  I'm not sure why you want to change the
> existing API, sounds like most of these features belong to a new atom
> interface, however I could be wrong.  Go ahead and send your proposal so
> we have a starting point for the discussion.
>
> Regards,
> -Denis

Before discussing the source code itself, I would like to know your 
opinion about the different alternatives that come into my mind.

When you talk about a new atom interface, we could:

a. Create an HFP interface that includes all bluetooth-specific 
extensions. This could something like org.ofono.Handsfree or 
org.ofono.HfpModem.
b. Be more consistent with the existing oFono API and split the new 
extensions into several interfaces, such as org.ofono.hfp.Modem and 
org.ofono.hfp.VoiceCallManager (and whatever else is needed). This 
second interface would support methods such as Redial() and AnswerAndHold().
c. If this second approach of hfp.VoiceCallManager is followed, we could 
not only include the extensions there, but also replicate the whole API 
in org.ofono.VoiceCallManager. Personally I would rather not do this, 
but it seems to me that org.ofono.cdma.CdmaVoiceCallManager has been 
designed that way.

My vote would be in favor of the first option, for the sake of simplicity.

What do you think? Any other alternative?

Regards,
Mikel

Re: Bluetooth HF role

[Denis Kenzior]

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Hi Mikel,

> 
> Before discussing the source code itself, I would like to know your
> opinion about the different alternatives that come into my mind.
> 
> When you talk about a new atom interface, we could:
> 
> a. Create an HFP interface that includes all bluetooth-specific
> extensions. This could something like org.ofono.Handsfree or
> org.ofono.HfpModem.

This is my preferred option.

> b. Be more consistent with the existing oFono API and split the new
> extensions into several interfaces, such as org.ofono.hfp.Modem and
> org.ofono.hfp.VoiceCallManager (and whatever else is needed). This
> second interface would support methods such as Redial() and
> AnswerAndHold().

I don't think this is a good idea, you lose much of the flexibility for
the applications; e.g. being able to implement the same API and work on
real modems, hfp devices, sap devices, etc.

Having said that, the +BTRH is a bit special.  I believe it is only
supported on CDMA networks, while the HFP protocol is modeled after the
GSM call model.  We might have to look into implementing it on
VoiceCallManager and tweak the GSM call state logic accordingly, which
won't be fun ;)  Any ideas are welcome here, I have no experience with
Response and Hold or access to networks with it enabled.

> c. If this second approach of hfp.VoiceCallManager is followed, we could
> not only include the extensions there, but also replicate the whole API
> in org.ofono.VoiceCallManager. Personally I would rather not do this,
> but it seems to me that org.ofono.cdma.CdmaVoiceCallManager has been
> designed that way.
> 

CDMA versions were designed this way because the CDMA call state machine
is dirt simple.  There didn't seem to be a need to make applications
deal with the complexity of the GSM API while having a much simpler
model underneath.

> My vote would be in favor of the first option, for the sake of simplicity.
> 
> What do you think? Any other alternative?

Nope, your proposal is in line with my current thinking.

Regards,
-Denis

Re: Bluetooth HF role

[Mikel Astiz]

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Hi,

On 09/08/2011 10:27 AM, Mikel Astiz wrote:
> Hi Denis,
>
> On 08/21/2011 04:13 AM, Denis Kenzior wrote:
>> Hi Mikel,
>>
>> On 08/25/2011 07:32 AM, Mikel Astiz wrote:
>>> Hi Denis,
>>>
>>> On 08/20/2011 11:00 AM, Denis Kenzior wrote:
>>>> Hi Mikel,
>>>>
>>>> On 08/24/2011 10:28 AM, Mikel Astiz wrote:
>>>>> Hi all,
>>>>>
>>>>> I'm trying to understand the features currently supported by oFono
>>>>> regarding the handsfree role in Bluetooth/HFP. My first impression
>>>>> looking at the source code is that some HFP functionality might be
>>>>> missing, but I would rather have your confirmation.
>>>>>
>>>> Correct, in general only features that map 1:1 to existing APIs are
>>>> exposed.  So that means network registration, voicecalls and call-volume
>>>> interfaces.
>>>>
>>>>> Some examples I've found so far are the following:
>>>>> 1. Response and hold (AT+BTRH=0)
>>>>> 2. Redial last number (AT+BLDN)
>>>>> 3. Retrieval of supported Bluetooth features for a certain modem/device
>>>>> (AT+BRSF)
>>>>>
>>>> BRSF is supported and used internally, but the information is not
>>>> exposed over D-Bus.
>>>>
>>>>> Could you clarify which (if any) of these features are currently
>>>>> supported by oFono?
>>>> Bluetooth specific features are not supported yet, these will require a
>>>> separate atom. Roughly this means anything starting with +B.. including:
>>>>       - +BINP
>>>>       - +BLDN
>>>>       - +BVRA
>>>>       - +NREC
>>>>       - +BSIR
>>>>       - +BTRH
>>>>
>>>>> In general, is there any documented list of unsupported features?
>>>>>
>>>> In general the TODO list is your best source of readily available
>>>> information.  In the case of HFP HF, there is no such documentation ;)
>>>> Patches adding tasks to the TODO list to support these features are
>>>> always welcome.
>>>>
>>>> Regards
>>>> -Denis
>>> OK, thanks for the information.
>>>
>>> Then I guess the next question is whether you have plans to support this
>>> in the future, or if you would accept patches in this direction. I'm
>>> afraid some of them could potentially affect the existing API.
>>>
>> Patches are always welcome.  I'm not sure why you want to change the
>> existing API, sounds like most of these features belong to a new atom
>> interface, however I could be wrong.  Go ahead and send your proposal so
>> we have a starting point for the discussion.
>>
>> Regards,
>> -Denis
> Before discussing the source code itself, I would like to know your
> opinion about the different alternatives that come into my mind.
>
> When you talk about a new atom interface, we could:
>
> a. Create an HFP interface that includes all bluetooth-specific
> extensions. This could something like org.ofono.Handsfree or
> org.ofono.HfpModem.
> b. Be more consistent with the existing oFono API and split the new
> extensions into several interfaces, such as org.ofono.hfp.Modem and
> org.ofono.hfp.VoiceCallManager (and whatever else is needed). This
> second interface would support methods such as Redial() and AnswerAndHold().
> c. If this second approach of hfp.VoiceCallManager is followed, we could
> not only include the extensions there, but also replicate the whole API
> in org.ofono.VoiceCallManager. Personally I would rather not do this,
> but it seems to me that org.ofono.cdma.CdmaVoiceCallManager has been
> designed that way.
>
> My vote would be in favor of the first option, for the sake of simplicity.
>
> What do you think? Any other alternative?

I forgot to add that another alternative would be to merge voice-call 
related extensions in the existing API. For example, by adding the 
method Redial() in org.ofono.VoiceCallManager, and extending the 
semantics of SwapCalls() to put incoming calls on hold.

Regards,
Mikel

Re: Bluetooth HF role

[Gustavo Padovan]

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Hi Mikel,

* Mikel Astiz <mikel.astiz@bmw-carit.de> [2011-08-24 17:28:35 +0200]:

> Hi all,
> 
> I'm trying to understand the features currently supported by oFono
> regarding the handsfree role in Bluetooth/HFP. My first impression
> looking at the source code is that some HFP functionality might be
> missing, but I would rather have your confirmation.
> 
> Some examples I've found so far are the following:
> 1. Response and hold (AT+BTRH=0)
> 2. Redial last number (AT+BLDN)

Yeah, these are missing.

> 3. Retrieval of supported Bluetooth features for a certain
> modem/device (AT+BRSF)

This is done by hfp_slc_establish() in hfp_hf.c plugin.
> 
> Could you clarify which (if any) of these features are currently
> supported by oFono?
> 
> In general, is there any documented list of unsupported features?

No, I think you need to confront the code against the spec.

	Gustavo