Dialogic D/4PCI

4-Port Voice Processing for Small and Medium Enterprise Applications

Features and Benefits

• Build flexible, cost-effective messaging and voice response platforms for small- and medium-sized enterprise applications
• Supports Windows NT* including TAPI/WAVE*
• CTR-21 approvals mean expanded markets
• Caller ID lets applications perform intelligent call handling
• Delivers advanced call processing features and enables competitive differentiation by supporting software-based features such as
  - Global Dial Pulse Detection
  - PBX Expert tone characterization utility
• Provides reliable DTMF detection during voice playback, letting callers "type-ahead" through voice menus for quicker completion of call transactions
• Ensures reliability via call progress analysis which monitors outgoing call status quickly and accurately
• Flexible voice coding at dynamically selectable data rates, 24 to 64 Kb/s, selectable on a channel-by-channel basis for optimal tradeoff in disk storage and voice quality
• Superior voice quality through enhanced telephone circuitry and automatic gain control
• Half-size PCI form factor enables developers to build cost-effective systems by using the most up-to-date industry-standard chassis. The ability to mix form factors offers a cost-effective transition to the PCI form factor.
• Compatible with legacy telephone switches in the United Kingdom and Northern Europe that use Earth Recall signaling

Applications

• Networked voice messaging
• Automated attendant
• Interactive voice response
• Enhanced messaging

The four-line D/4PCI board is useful for small- and medium-sized enterprise computer telephony (CT) applications that require high-performance, cost aggressive voice processing but don't need the large-scale system sophistication of SCbus or CT Bus* based products. The D/4PCI board uses the same application programming interface (API) as its predecessors, making it easy to scale existing applications to take advantage of its power and features. The D/4PCI board has improved voice quality and automatic gain control (AGC) so that even the weakest telephone signals can be recorded and replayed with clarity.

The D/4PCI board uses digital signal processor (DSP) voice processing technology, making it ideal for server-based CT systems - particularly under the Windows operating systems. Windows support includes TAPI and WAVE APIs which facilitate call control, recording, and playback of voice messages under the Microsoft Windows Open Services Architecture (WOSA)* and lets developers quickly develop robust unified messaging applications. The D/4PCI voice processing board gives Windows NT application developers a powerful platform for creating sophisticated interactive voice response (IVR) applications for the small- and medium-sized enterprise market. Caller ID support lets applications such as IVR receive calling party information via a telephone trunk line. Caller ID is supported for North America (CLASS* protocol), the United Kingdom (CLI protocol), and in Japan (CLIP protocol).

The Global Dial Pulse Detection (DPD) algorithm is available for the D/4PCI board, enabling applications to be deployed in countries with limited touchtone telephone service. Global DPD is optimized for a number of countries and provides superior dial-pulse detection.

With all of these advanced features in a half-size PCI board footprint, the D/4PCI board is optimal for client or small server system development. The board offers DSP power and memory capacity that provide a base level of performance for requirements as well as the "head room" for future application expansion via software-based technologies.

Configurations

Use the D/4PCI board to build sophisticated messaging and IVR systems with optional technologies such as automatic speech recognition (ASR), TTS, Global DPD, and PBX Expert software. The D/4PCI board shares a common hardware and firmware architecture with other Intel® Dialogic® voice boards for maximum flexibility and scalability. More ports and new features can be added to a solution while protecting your original investment in hardware and application code. Applications can be ported to higher line density platforms with only minimum modifications.

The D/4PCI board installs in Intel® processor-based computers (Intel486® or Pentium® processor based PC platforms) and provides for building integrated, non-CT Bus voice solutions, scalable from 4 to 64 ports.

Software Support

The D/4PCI board is supported by the System Software and software development kit (SDK) for Windows NT. The SDK contains all the documentation, demonstration code, and tools necessary for developing complex multichannel applications.

Functional Description

The D/4PCI voice processing board builds on the patented dual-processor architecture that combines the signal processing capabilities of a DSP with the decision-making and data movement functionality of a general-purpose control microprocessor by using faster processors and considerably more memory. This dual-processor approach offloads many low-level decision-making tasks from the host computer, thus enabling easier development of more powerful applications. This architecture handles real-time events, manages data flow to the host PC for faster system response time, reduces host PC processing demands, processes DTMF and telephony signaling, and frees the DSP to perform signal processing on the incoming call.

Each of the four loop start interfaces receive analog voice and telephony signaling information from the telephone network (see Block Diagram). Each telephone line interface uses reliable, solid-state hook switches (no mechanical contacts) and FCC-part 68 class B ring detection circuitry. This FCC-approved ring detector is less susceptible to spurious rings created by random voltage fluctuations on the network. Each interface also incorporates circuitry that protects against high-voltage spikes and adverse network conditions and lets applications go off-hook any time during ring cadence without damaging the board.

Part of the telephone interface for the D/4PCI board includes an on-hook audio path that detects Caller ID information. Depending on the level of service offered by the local telephone provider, Caller ID can include the date, time, caller's telephone number, and in some enhanced Caller ID environments, the name of the person calling. The on-hook audio path can also detect touchtones while the line is on-hook. This capability lets the board operate behind PBXs that require on-hook touchtone detection for their signaling.

Inbound telephony signaling (ring detection and loop current detection) are conditioned by the line interface and routed via a control bus to the control processor. The control processor responds to these signals, informs the application of telephony signaling status, and instructs the line interface to transmit outbound signaling (on-hook/off-hook) to the telephone network.

The audio voice signal from the network is bandpass filtered and conditioned by the line interface and then applied to a COder/DECoder (CODEC) circuit. The CODEC filters, samples, and digitizes the inbound analog audio signal and passes this digitized audio signal to a Motorola DSP.

Based on Spring Ware firmware loaded in DSP RAM, the DSP performs the following signal analysis and operations on this incoming data:

• uses AGC to compensate for variations in the level of the incoming audio signal. The D/4PCI board also includes special circuitry to detect and amplify extremely weak line signals due to harsh telephone line conditions or back-to-back local loops often found in 800 (toll-free) service environments
• applies an adaptive differential pulse code modulation (ADPCM) or pulse code modulation (PCM) algorithm to compress the digitized voice and save disk storage space
• detects the presence of tones - DTMF, MF, or an application-defined single- or dual-frequency tone
• uses silence detection to determine when the line is quiet and the caller is not responding

For outbound data, the DSP performs the following operations:

• expands stored, compressed audio data for playback
• adjusts the volume and rate of speed of playback upon application or user request
• generates tones — DTMF, MF, or any application-defined general-purpose tone

The dual-processor combination also performs the following outbound dialing and call progress monitoring

• transmits an off-hook signal to the telephone network
• dials out (places an outbound call)
• monitors and reports results: line busy or congested; operator intercept; ring, no answer; or if the call is answered, whether answered by a person, an answering machine, a facsimile machine, or a modem

When recording speech, the DSP can use different digitizing rates from 24 to 64 Kb/s as selected by the application for the best speech quality and most efficient storage. The digitizing rate is selected on a channel-by-channel basis and can be changed each time a record or play function is initiated. The popular 11 kHz, 8-bit linear multimedia WAVE format is also supported on the D/4PCI voice board.

Outbound processing is the reverse of inbound processing. The DSP processed speech is transmitted by the control microprocessor to the host PC for disk storage. When replaying a stored file, the microprocessor receives the voice information from the host PC and passes it to the DSP, which converts the file into digitized voice. The DSP sends the digitized voice to the CODEC to be converted into analog voice and then to the line interface for transmission to the telephone network.

The on-board microprocessor controls all operations of the D/4PCI board via a local bus and interprets and executes commands from the host PC. This microprocessor handles real-time events, manages data flow to the host PC to provide faster system response time, reduces PC host processing demands, processes DTMF and telephony signaling before passing them to the application, and frees the DSP to perform signal processing. Communications between this microprocessor and the host PC is via the shared RAM that acts as an input/output buffer and thus increases the efficiency of disk file transfers. This RAM interfaces to the host PC via the PCI bus. All operations are interrupt-driven to meet the demands of real-time systems. All D/4PCI boards installed in the PC share the same interrupt line. When the system is initialized, Spring Ware firmware is downloaded from the host PC to the on-board code/data RAM and DSP RAM to control all board operations. This downloadable firmware gives the board all of its intelligence and enables easy feature enhancement and upgrades.

Technical Specifications**

Spring Ware Firmware Technical Specifications**

*All company names, products, and services mentioned are the trademarks or registered trademarks of their respective owners.

** All specifications are subject to change without notice.

† Analog levels: 0 dBm0 corresponds to a level of +3 dBm at tip-ring analog point. Values vary depending on country requirements; contact your Technical Sales Representative.

‡ Average speech mandates +16 dB peaks above average and preserves -13 dB valleys below average.

Hardware System Requirements

80486, or Pentium® processor-based computer. Operating system hardware requirements vary according to the number of channels being used.