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Pulse Dialing Detector

Overview

This section describes the addition of a pulse dialing detector into the DSP Series 2 card of the CSP.

Both DTMF and Dial Pulse detection are supported. Dial Pulse detection is co-resident with the DTMF detector and supports all of the features associated with the DTMF signal detection, such as record/playback cancellation on detection. The DTMF and Dial Pulse detectors will have the same densities as the DTMF detector alone (192 bits per stream).

It is common in some areas to have legacy switches and telephones that only support pulse (rotary) dialing. By incorporating a pulse dialing detector, the CSP will enable the customer to develop applications which accept user input from callers who do not have DTMF-capable telephones.

APIs and TLVs Used to Configure this Feature

To configure this feature, the host may optionally send a Generic Card Configure (0x0122) message to the DSP Series 2 card to change the default parameters to enable pulse dialing. These configurable parameters are provided in the modified Card Object (0x05FA) TLV and the new Dial Pulse Detection Parameters (0x0750) TLV. Default settings are provided by the customer. All configurable parameters can be queried using the Generic Card Query (0x0123) message.

Following this optional configuration, the DSP SIMM Configure (0x00C0) message will enable DTMF/Pulse dialing on the CSP. When the call is setup, a DSP Service Request (0x00BD) message or Collect Digit String (0x00BC) message enables the DSP Series 2 card to begin receiving pulse or DTMF digit indications. In the case of a DSP Service Request, these digits will show up individually, and in the case of collect digit strings, the digits will show up when the requested digit string arrives. Pulse dialing can be canceled using the DSP Service Cancel (0x00BE) message.

Call Flow

The following call flow shows the basic configuration for setting up pulse dialing.

Dial Pulse Detection Parameters (0x0750) TLV

The Figures 7-7 and 7-8 aid in describing the Dial Pulse Detection Parameters (0x0750) TLV. Refer to this TLV in the API Reference.

Figure 8-7 Representative Pulse Digit

Figure 8-8 State Machine Detection of Dial Pulses

Digital Signal Processor
Tag-Length-Value block. A standardized block that allows data to inserted in a standard way into API messages.
The condition of a component at a given instant. The current "context" of a PPL object, such as Idle, Seizing, Answered. In PPL files, a State is represented by a circle.