Copyright: Version 1.10, Copyright 1998, Northern Telecom (Nortel), Ltd.


Introduction

CPTDUtil

CPTDUtil is a utility which allows the user to view and modify Call Progress Tone Detection (CPTD) parameters for an specific country which can be selected from a list of existing countries. These parameters are saved in a Common Object File Format (COFF)  and stored in DSP flash memory. Then, they are used by Host application to configure the CPTD module prior to an outcalling session.

The configuration file includes of the following parameters for each country:

•	Cadence parameters

•	Digital filters coefficients

•	Timing Values

•	Non-Repeating Tones parameters

•	Special Information Tone (SIT) data

Applications

•	View Call Progress Tone Detection parameters and their descriptions

•	Modify above parameters for each and every country

•	Add a new country or Delete an existing one

•	Create COFF output file to be stored in flash with other DSP files


Overview of Features

The CPTDUtil Utility can perform the following functions:

•	Parameters Display

•	Parameters Modification

•	List of Countries

•	Restore CPTD File

•	Create COFF File


Cadence Parameters Display

When a country has been selected, its cadence parameters can be displayed in the Display window along the bottom of CPTDUtil. This can be done by pressing “View Cadences” button on the main form.

There are 36 cadences that can be defined for each country. However, usually only few of them are defined. When you display cadence parameters, there has to be at least one defined as “Linebusy” and one as “Ringback”. The rest can be left unassigned.

Cadences Values

Each cadence has an On-Off, On-Off-On-Off or On-Off-On-Off-On-Off repetition. For every value there are a maximum and a minimum number. All the values are in msec and they are rounded to a nearest 16ms multiply. Therefore, for every defined cadence there has to be 4 or 8 or 12 values defined. Anything else in not correct. This rule will also apply when the user wants to define a new cadence. To view all the cadences and all the values you have to scroll up and down, left and right on above window. Window can be cleared by pressing “Clear Window” button provided right under the display.

This window only allows users to display cadences. In order to modify cadences see Cadence Modification


View Filter Coefficients

The CPTD module utilized five high-pass and band-stop digital filters to filter input signals. They are:

1) 	InBand Filter: This filter is used to detect inband signals such as DialTone, BusyTone, RingBack, ReorderTone,  etc.

1) 	SITBand1 Filter: This filter is used to detect SIT1 frequencies.

1) 	SITBand2 Filter: This filter is used to detect SIT2 frequencies.

1) 	SITBand3 Filter: This filter is used to detect SIT3 frequencies.

1) 	Modem Filter: This filter is used to detect Modem, Fax/CED frequencies.

In order to view filter coefficients after you select your desired country, click on the “View Filter Coef.” button on the main window:

As a result all existing five filter coefficients for your specific country will be displayed in the large window used to display Cadence Parameters


Cadence Modification

The user can modify cadences for different countries, one cadence at a time. In order to modify cadences, make sure you have already selected the desired country from the available list and then press “Modify Cadences” from the main from.

Select a country from the list

A pop up menu will appear immediately which will guide you to modify cadences for your specific country. The first step is to select a cadence number from the list in the “Cadence Number” box. To view default values for selected cadence click on “Default” button at the bottom middle of the window. As a result “Cadence Report”, “Cadence Type” and “Cadence Values” will be presented.

To modify this specific cadence, Select cadence report, cadence type and enter your desired cadence values in the fields provided. Notice type 1 means On-Off cadence and you have to enter first four values. Type 2 means On-Off-On-Off cadence and you have to enter the first eight values and so on. However, if you enter the “Type” incorrectly, the program will correct it if you enter correct number of cadence values in the fields. Make sure you avoid entering odd number of

values. Otherwise you will confuse the system (you only can enter 4, 8 or 12 values).

After values entered, press “Apply” button to make the changes permanent. An easy test to verify your values are there is to reopen “Modify Cadences” pop up window and view the default values for the same cadence or check the View Cadences window.


Modify Filter Coefficients

Modifying digital filters’ coefficients may dramatically change the way CPTD module will perform. Extra caution has to be take to account when you work with these filters. These modification are required in cases that call progress tones for a specific country are slightly out of the filter’s range.

To modify press “Modify Filters” button on the main window. You will be presented with a pop up window as follows:

The first step is to pick a filter from the list in the “Filter Types” box and hit the “SELECT” button. The current (default) values for your filter will be presented in a modifiable fields. Enter your new values and  press “Apply” to make the changes.

You need to use a third party software to design your new coefficients for the specific filter.


Non-Repeating Tones

View/Modify Non-Repeating Tones

Similar to cadences, Non-Repeating tones have a cadence but they do not repeat themselves (they happen only once). Not every country has any Non-Repeating Cadences defined for them, however CPTD module can be configured for up to 8 Non-Repeating cadence. To view these parameters click on “View parameters” in Non_repeating Tones box in front window. The parameters (cadences) will be displayed in the same large window which was used to display Cadence Parameters.

To modify or redefine any of these cadences, select “Modify Parameters” in the Non-Repeating Tones Box. You will be presented with a following pop up menu:

The first step is to select a cadence from the list and then hit “Default”. All the fields except Country ID and name are modifiable. Enter your desired values in the fields (or select them form the available from the list where ever possible) and hit apply. Your changes will be permanent.


Threshold Table

Threshold table is used by CPTD module for energy detection. To view them press “Threshold Table” in the Misc. Box on front form. A window will be poped out and has modifiable fields:

Every field represents two values; 1) Energy Value, 2) Percentage. It means, when CPTD filters the input signal, if the energy of the filtered signal is greater than X value, Y percent of the total energy (energy of the unfiltered signal) has to be in the filter’s bandwidth. For example if you read X=-31dBm and Y=80%, this means that the filtered energy has to be greater than 80% of the total energy, since total energy level is higher than -31dBm.

To modify, enter your desire values in the above fields and press “Apply”.


Time-Out Values

These are very important values and rarely require any modification. These values show how CPTD detect and when it reports the detected result.

In order to view and modify these values select “Timeout Values” in main window. Again, you will be presented with a window that enables you to view and modify timeout values for selected country.

For Viewing, select default. To modify select new values from the list provided for each value or directly enter them into the fields and press “Apply”.


SIT Data

Users never have to modify these values. However if you desire to modify these values, consult with a DSP designer or a knowledgeable product support personnel.

To View or modify click on “SIT Data” button on the Misc. Box in front window:

By pressing on “Default” button you can view the current values. In order to modify, enter new values and press “Apply.


Parameters Display

CPTDUtil provides the following viewing functions via its Main Menu:

Cadence Parameters View: will allow you to view every country’s cadence parameters.

Filter Coefficients View: option will allow you to display digital filters coefficients.

Non-Repeating Parameters View

Threshold Table View/Modify: option will allow you to display and modify (if desired) threshold values.

TimeOut Values and SIT Data Values


Parameters Modification

CPTDUtil also provides the following modification functions via its Main Menu:

Cadence Parameters Modification: option will allow you to view a specific cadence and modify it if desired. It also allows users to define a new cadence or unassigned a defined one.

Filter Coefficients Modification: To display and modify digital filter coefficients this option can be used

Non-Repeating Parameters Modification

Threshold Table, TimeOut Values and SIT Data Values


List of Countries

CPTDUtil enables users to select a country from a list of countries to modify or view its parameters. When a country is selected its parameters are read from an input COFF file and initialize the utility.

To select a country, choose a name from the “List of Countries” in the main form the exact same way that was done in Cadence Modification when a country had to be selected.


Add New Country

Utility allows users to add a new country to the list of existing countries. To do so, press “Add New Country” from Countries box. The following window will appear asking you to enter the name of your new country:

You may add a new name up to 20 characters. After you press “OK” the new country will be added. However, to be able to see this new country’s parameters you need to refresh the list.

Notice that, when a new country is added it contains a set of default values. It is the responsibility of the user to modify its new added country’s parameters accordingly.

If you added a country, you may remove it in two ways:

1)  Use Delete Country option from the main form

2)  Restore CPTD File CPTD file before you exit the utility. If you choose to select this option, all the changes you made since you have started your utility, will be lost.


Delete Country

CPTDUtil will enable users to delete a country that they just added. In order to delete a country press “Delete Country” button on the main window and already selected country will be deleted. You can not delete any original country from the list. Therefore, a new country can only be deleted, before you exit the utility and only if the country has just been added.


Restore CPTD File

If you make any mistake while you are trying to modify CPTD parameters, and you don’t remember the original values  of those parameters, you can restore the defaults by using this option. However, this option can only be used before you exit the utility. After you exit, all the changes you were made become permanent.

To restore the CPTD parameter file click on “Restore CPTD file” button:


Create COFF File

As you might have noticed, CPTDUtil reads every country’s parameters from a file. The same file will be used to be stored in the Flash Memory on a real DSP system. To be able to program the flash memory, there are other tools which have been developed. These tools access Common Object Format Files (COFFs), extract their binary contents and store them in flash. Therefore it is absolutely necessary for the users of this utility to create a COFF file before they exit.

There are three ways that you an exit the utility:

1) 	Clicking on “close icon”  in the corner of the main frame

If you click on the (X) at the corner to close the utility and you have not created the COFF file, utility will warn you that you have not created the output COFF. However, it will exit and you have to run it again and create the output COFF file.

1) 	Close the form by clicking on the icon on the left upper corner

This is the same scenario as the one above.

1) 	Using File menu and Exit

If you have not created the COFF file the utility warns you and doesn’t let you exit until you do so. Therefore, it is recommended you always use this method to exit the CPTDUtil. Notice that when you run the utility you have to create the COFF file before you exit , even though you have not made any changes.

To create the CPTD parameter COFF file click on “Create COFF file” button:


InBand Filter

The CPTD module is using a high-pass digital filter filtering on an 8KHz sampled. The characteristic of this filter is as follows:

All the Inband tones frequencies lie between 350Hz to 620Hz. The CPTD calculates the Total energy of the signal and  subtracts the Outbound energy from it. If the result is greater than 80% of the total energy, it has detected signal existence in the desired band (InBand). Followings are InBand tone frequencies for country of Canada

•	DialTone:	350Hz + 440Hz

•	Ringback:	440Hz + 480Hz

•	Linebusy:	480Hz + 620Hz

•	Reorder:	480Hz + 620Hz

All the InBand tones are cadenced and they are distinguished from each other based on that.


SITBand1 Filter

The CPTD module is using a band-stop digital filter filtering on an 8KHz sampled to detect SIT1 frequencies. The characteristic of this filter is as follows:

All the SIT1 frequencies lie between 913Hz to 985Hz. The CPTD calculates the Total energy of the signal and  subtracts the Outbound energy from it. If the result is greater than 80% of the total energy, it has detected signal existence in the desired band (SIT1).


SITBand2 Filter

The CPTD module is using a band-stop digital filter filtering on an 8KHz sampled to detect SIT2 frequencies. The characteristic of this filter is as follows:

All the SIT2 frequencies lie between 1370Hz to 1428Hz. The CPTD calculates the Total energy of the signal and  subtracts the Outbound energy from it. If the result is greater than 80% of the total energy, it has detected signal existence in the desired band (SIT2).


SITBand3 Filter

The CPTD module is using a band-stop digital filter filtering on an 8KHz sampled to detect SIT3 frequencies. The characteristic of this filter is as follows:

The SIT3 filter only has to detect one frequency which is 1776Hz. The CPTD calculates the Total energy of the signal and subtracts the Outbound energy from it. If the result is greater than 80% of the total energy, it has detected signal existence in the desired band (SIT3).


Modem Filter

The CPTD module is using a band-stop digital filter filtering on an 8KHz sampled to detect Fax/Modem (CED) frequency. The characteristic of this filter is as follows:

The Modem Filter only has to detect one frequency which is 2250Hz. The CPTD calculates the Total energy of the signal and subtracts the Outbound energy from it. If the result is greater than 80% of the total energy, it has detected signal existence in the desired band (CED/Modem).