<p>Standard in Altigen's (Los Angeles, CA – 510-252-9712, AltiServe software is a 2000 voicemail boxes, an auto attendant with scripting capabilities, and Zoomerang. This last feature lets outside users successively retrieve and answer voice messages.</p>

A lot of these products are for scientific markets such as plasma diagnostics in fusion research,” said Robertson. Millimeter-waves are used to measure parameters such as temperature and pressure through the plasma. The quasi-optical properties are also important in radio astronomy. Another potentially large market is automotive radar which can tell you how close you are to the car in front.”

Tune your grammars. Applications written to the VoiceXML standard can simply list the text of words (grammars”) that should be recognized as voice commands at any given recognition event. While this will achieve a base level of ASR performance, you need to tune those grammars to get the highest accuracy. This involves (1) including multi-syllabic commands and phrases and their synonyms, (2) specifying alternate pronunciations of commands, (3) using voice commands that are most dissimilar, and thus easier for the recognizer to distinguish, (4) adding command utterances that include extraneous words like um,” please,” eh,” etc., and (5) assigning probabilities for each word or phrase.

Tune the ASR engine using live utterances. This step takes effort, but can improve recognition accuracy. Start by collecting thousands of live caller command utterances from several hundred individual speakers. Transcribe them so the actual words spoken are known for each command sample. Now you have samples gathered from a variety of callers, under a variety of call and noise environments.

FXUYL7E7EAAM079_Datasheet PDF

Play these samples through the recognizer, using the transcriptions to identify the command spoken. Use provided tools to adjust the ASR parameters. The goal is to minimize false negatives and false positives. Repeat this process until peak ASR accuracy is achieved. This step may also reveal problems with the words and phrases in the grammar. Todd suggests re-collecting command utterances and transcribing them if your application changes. You may need help from the ASR vendor the first time you do this.

Build a VoiceXML generator. You may want to write your first application in static VoiceXML for debugging and usability testing. A next step might be making database queries from within static VoiceXML code, yielding a more dynamic application that branches based on database content. However, a program that actually generates VoiceXML code just-in-time may be the smartest course. A VoiceXML generator can be modeled after an HTML-generating middleware package, with some of the same modules tweaked” for this new purpose. Todd suggests the Apache web server with the appropriate plug-in modules as a good starting point.

Buy a VoiceXML interpreter and platform. There is no need to write your own VoiceXML interpreter today; multiple vendors sell relatively mature products in this area. When selecting a vendor, carefully evaluate the interpreter and platform's scalability and compliance with the VoiceXML 2.0 specification. Depending on your app, you may want to install and maintain your VoiceXML platform at a carrier-grade co-location facility. Be sure to include failover procedures for your VoiceXML generator, database, and VoiceXML platform. And if you want to run your VoiceXML application on a third-party host, a number of companies are in that business (see

FXUYL7E7EAAM079_Datasheet PDF

Verify alternate pronunciations from your grammar compiler. The ASR grammar compiler is a powerful tool and should add alternate pronunciations to the words in the grammar being compiled. These are sometimes kept in a dynamic grammar database.

Develop a rigorous test suite. You may want to consider getting a test platform such as the Empirix Hammer (, a scriptable call generator that can inject large numbers of calls into the voice platform. The Hammer can be programmed with an exhaustive functional test that exercises virtually any path through a voice application. Run this test suite whenever application code changes.

FXUYL7E7EAAM079_Datasheet PDF

Developing a usable and accurate carrier-grade VoiceXML application takes much time and effort. After following Todd's steps, your application should at least be ready for friendly” users. Then use their feedback to tune further.

Chris Bajorek is co-founder of CT Labs, an independent full-service converged communications and IP Telephony product testing and certification lab. Chris can be reached at .

Some of the early customers of the device, such as Rockwell Collins Inc., are considering using it as a prototyping vehicle that can be converted by Altera into less expensive mask-programmable devices for high-volume production, according to Altera.

Altera and foundry partner TSMC started working together about one year ago on a 0.13-micron process recipe suitable for the EP2A70. The two companies have collaborated in a similar way before, since such cooperation gives Altera an edge over TSMC's standard process technology offerings. In turn, TSMC uses the large PLD design as a vehicle to test defect density, yield and logic performance so that it can tune its process accordingly.

For the 0.13-micron technology node, TSMC has come up with four standard process modules, which vary by core voltage, gate dielectric oxide thickness, transistor threshold voltages, metal pitch and other factors. Altera's EP2A70, however, uses a specialized 1.5-volt overdrive option for a transistor initially designed for 1.2-V operation.

Altera chose this route to get the optimal transistor performance while keeping leakage current under control.

The main source of leakage current today is subthreshold leakage, also known as off-state leakage, which is caused by current flowing beneath the surface of a transistor's source/drain channel. To counter this effect, chip manufacturers can tune a device for a higher operating voltage. In this case, Altera chose the 1.5-V core voltage instead of the standard 1.2-V offering.


In September, Mosaid filed a DRAM patent lawsuit Samsung, after the Canadian company said licensing negotiations had broken down with a major memory maker. The suit covers a range of U.S. patents dealing with basic inventions and fundamental technologies required for DRAMs, according to the Ottawa company (see Sept. 13 story ).

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