Data Quality Request

Product:	ZDK
Category:	Data
Subject:	Data Quality Request
Page:	1 of 1

Data Quality Request

You can not be sure of the capabilities of the far end prior to establishing a call. The modes and channel sizes supported by the far end are unknown until the call is actually made. There is an exchange of capabilities after connection. A list is created of what is supported. A 128K data mode cannot be specified prior to connection as it may not be supported. But when a call is established, a mode must be selected for the call.

To solve this problem the classes and custom controls contain a concept called the Quality Request. For Video, Audio, and Data the application requests the quality needed for a call. These are given in general terms, such as smallest, best or smart. When a call is established the quality request instructs the class how set up the channel allocations.

The complete list of data quality requests is:

C++	Custom Control	Value
DATA_ALG_NODATA	ZYD_BANDWIDTH_OFF	0
DATA_ALG_SLOWEST	ZYD_BANDWIDTH_LOW	1
DATA_ALG_SMART	ZYD_BANDWIDTH_SMART	2
DATA_ALG_FASTEST	ZYD_BANDWIDTH_HIGH	3
DATA_ALG_MIRROR	ZYD_BANDWIDTH_MIRROR	4

Selecting no data (DATA_ALG_NODATA) will not allocate any video bandwidth for the data.

Selecting mirror mode (DATA_ALG_MIRROR) will allocate the amount of data that the far end allocates.

Smart data (DATA_ALG_SMART) works with smart audio (AUDIO_ALG_SMART) to assemble the highest data bandwidth supported by both sides. If no file transfer is being performed, or no serial port is emulated, the data bandwidth allocation is zero. When one of these operations is performed, smart data starts to reassemble the bandwidth allocations to optimize the data. If smart audio is selected, audio is brought down to the lowest size audio mode available, else audio is left alone. The listing of supported data modes is searched. In searching, 32K is reserved for the video. The highest data mode is then selected and set.

There is one exception to the above algorithm for smart data - the sending of notes or text. To optimize the speed of sending notes, the data mode is set to the lowest data mode and audio is left alone. When smart data is finished, it will bring the data channel back to zero length and restore smart audio to its previous mode.

The functions associated with the video request are:

CZ_Call::GetSendDataQuality(); CZ_Call::SetSendDataQuality();

In the custom control the property to set is:

DataRequestThe Affects of Smart Data

Smart Data is the expert sub-system of the Zydacron classes. When smart data is selected, and an event happens which involves data, Smart Data will examine the situation and determine the best way to reconfigure the phone call to optimize the data operations of the call. When smart data is selected, and there is no data operation active, the data is set to off (or a size of 0.)

Smart Data works with Smart Audio. If Smart Audio is selected, the audio is set to high fidelity when the call is created. When a data operation is performed, Smart Data will see that Smart Audio is selected and may bring audio down to low fidelity to provide for a larger data size.

Here are some scenarios and how Smart Data reacts:

Smart Audio is selected for the call and a file transfer is started. Smart data will bring audio down to low fidelity and calculate the highest data mode available. It will then change to this mode and start the transfer. When the transfer is complete it will bring data back down to off and bring audio back up to high fidelity.

Smart Audio is not selected for the call and a serial port is emulated. Smart Data will not touch audio and calculate the highest data mode available and set this mode. When the serial port is un-emulated the data will be brought down to off.

Smart Audio is selected and a note is sent to the far end. Notes are seen as low priority to Smart Data, so to save time for the reconfiguration, audio is not changed and the data is set to the lowest mode available. After the note is transferred the data is brought back to off.

Smart Audio is not selected and the user has selected a specific data mode and a file transfer is started. Smart Data will not perform any reconfiguration if a specific data mode, other than off, is selected. The selected data mode is used.

Last reviewed: 11-Sep-97

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