Freescale Semiconductor 94001480400/D ユーザーズマニュアル

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ARCHIVED BY FREESCALE SEMICONDUCTOR, INC. 2005
ARCHIVED BY FREESCALE SEMICONDUCT
OR,
 INC.
 2005
Call Active (Ongoing Audio Connection)
MOTOROLA
System Operational Modes
3-3
Preliminary
It is up to the AG to decide the right behavior in this situation. Possible actions include dialing a 
pre-programmed number, requesting user input via a pop-up window, or prompting the user for spoken 
input for speech recognition processing. However, the AG will be expected to add a voice connection over 
the established data connection at some point, in accordance with the Bluetooth specification.
The headset supports an immediate disconnect from the AG followed by reconnecting the units using an 
incoming connection from the AG, should this facility be desired in order to ensure that the AG is always 
master of the link during normal system use. This will give the AG total control of when to set the headset 
in low power Sniff Mode. After having reversed the connection, the headset operates as if the connection 
had been incoming in the first place, see Chapter 3.4, “Call Active (Ongoing Audio Connection)”. A more 
elegant scheme for obtaining the same result is to perform a regular master/slave switch, which is also 
supported by the headset. The headset will never request a master/slave switch on its own.
As if an incoming connection was established, the headset will request entering Sniff Mode in order to 
save power.
3.4   Call Active (Ongoing Audio Connection)
An active call (ongoing audio connection) is indicated by the headset LED. To adjust the speaker volume, 
use the VOL+ and VOL- buttons. A single press on VOL+ increases the volume one setting, holding down 
the button increases the volume repetitively.
The AG may modify the headset volume setting using the VGS command specified in the Bluetooth 
specification. As an example, a mobile phone can use this feature to reflect the setting of the phone speaker 
volume by adjusting the headset speaker volume accordingly. Conversely, the AG is notified of any 
changes in the speaker level settings due to input from the headset MMI to allow the AG to keep track of 
the present settings.
To mute the headset microphone (for example, to carrying out a conversation with a colleague without 
disturbing the caller), press the BT button. The activation of muting will be acknowledged through an 
audible alert, which will be repeated at intervals. The user will still be able to hear the caller. Muting is not 
indicated to the AG.
The link quality is monitored at intervals whenever an audio connection between headset and AG exists. 
Should the link quality decrease below a specific threshold, the user is warned through an audio indication. 
This action is taken both to remind the user of the reason for the degrading audio quality experienced, and 
to indicate that this is a known system situation, as opposed to an unknown failure. The link quality may be 
increased by the user moving closer to the AG or removing any obstacles between him and the AG. When 
the link quality has been increased to a level somewhat superior to the threshold mentioned above 
(hysteresis), the audio indication is stopped.
When the link quality is good, that is, few packets are lost on the link, it is desirable to use the most 
compact audio transmission mode, to avoid using the entire link bandwidth. This in turn allows power 
saving by powering down the radio when not receiving or transmitting. However, when the link quality 
deteriorates, a more robust transmission mode is desirable. To ensure this, the headset will attempt to 
switch packet type depending on the link quality. HV3 packets are used by default, but the headset will 
switch to HV1 packets in case of very poor link quality.
 
   
  
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