Template-based framework for building VoiceXML application Jonathan Law

Agenda What is VoiceXML ? System overview Development platform Template-based Application Framework Design process Deployment platforms

What is VoiceXML ? VoiceXML is an extension of XML VoiceXML 1.0 is a specification of VoiceXML Forum VoiceXML is a Web-based markup language for representing human-computer dialogs VoiceXML leverages the Internet for voice application development and delivery VoiceXML is not a universal solution to making web pages voice accessible

History of VoiceXML ? It started back in 1995 with AT&T researchers VoiceXML combined Phone Markup Language (PML- AT&T & Lucent), SpeechML (IBM) and VoxML (Motorola) The founding companies are Lucent, IBM, Motorola and AT&T VoiceXML 1.0 came out in March 2000 and accepted by W3C in May 2000 VoiceXML 2.0 draft released in January 2001

Voice-centric Devices

Multi-Channel System Architecture

IDE Tools IBM Voice Server and Apache Forum Apache Web Server PHP mySQL PHP IBM Voice Server

Voice Web Architecture

Development Platform Open source Apache Forum Products on Windows NT 4.0 Web Server - Apache HTTP Server Database - mySQL Server Side Scripting - PHP VoiceXML server - IBM ViaVoice SDK

Design Objectives Distinct layers architecture (presentation layer, business logic layer and data access layer) Scalable architecture based on J2EE (enable vendor independence, RAD workflow process) Abstract data access layer (allow easy plug-n-play for new data access channels) Easy of use and user-friendly (separate designer and programmer skill sets) Abstract execution environment (allow multiple-content to multiple devices)

VoiceXML Essentials Each application has one or more VoiceXML documents Each document has one or more dialogs Each dialog can be either informational or interactive Informational - prompts Interactive - requests and responses

Basic Elements - root element - define interactive or informational dialog - container for executable elements - play audio file or synthesized speech (TTS) - navigates to another dialog block

Simple VoiceXML application The elements are arranged in a nested hierarchy according to the specification of VoiceXML DTD v 1.0 welcome to Pace University Speech Lab

Template-based Application Framework Benefits Ease of use, easy to understand Short learning curve Proven Apache Forum shareware Based on J2EE standard, JSP compatible Fast, Very Fast performance Scalable, abstract architecture Reusable component Abstract execution environment Flexible delivery system to multiple devices

Template-based Application Framework Components Framework contains 6 modules Resources - resource bundles, config files Prompts - pre- recorded wave files, text for prompts Grammars - grammars files Templates - dialog designs Includes - sources code, common Common - XML DTD, DB abstract, generic codes

Application Framework Design Classic Software Design Paradigm Model - manages the behavior View, responds to request, and instruction to change state View - manages the outputs Controller - Interpret input from user, command the model and change the view as appropriate Model Controller View

Application Framework mapping ControllerView Model

Implementation Process Dialog Design – Pre-recorded or TTS Build VXML component – speech objects – define grammar Map dialog with contents from DB tables – build API for data retrieval Apply Business Logic – map dynamic and static contents Unit testing via browser using PHP – call up each component through URL System Integration in VXML platforms

Dialog Design Basic Call Flow Control A Voice application is a collection of dialogs. The interpreter navigates from dialog to dialog in document source order. A dialog is referenced via the value of its id attribute. The id of each dialog within a document should be unique. The URL consists of a hash symbol (#) followed by the value of the element’s id attribute. Outside the document, the URL consists of the absolute or relative HTTP path to the document

Dialog Design Basic Call Flow Control example Good Bye Welcome to Pace U

Dialog Design Compare Audio and TTS Pre-recorder AudioText-To-Speech Resource LargeSmall VocabularySmallUnlimited IntelligibilityHighHighly Intelligible Voice QualityNatural PleasantMechanical Voice CustomizabilityMust re-record Unlimited CostExpensiveNegligible FlexibilityNoneUnlimited vocabulary

Build VXML components A simple dialog template {USERID_GRAMMAR} {USERID_PROMPT} {USERPWD_GRAMMAR} {USERPWD_PROMPT}

Build VXML components Define Prompts and Grammars <?php $USERID_PROMPT=' Please say your six digit user ID. '; $USERPWD_PROMPT=' Say your four digit password. '; $MENU_USERID_INVALID_PROMPT=' That user ID does not exist. Login again. '; $MENU_USERPWD_INVALID_PROMPT=' That password is incorrect. Login again. '; ?> Example of a prompt file for US_EN

Build VXML components Define Grammars <?php $USERID_GRAMMAR='src=builtin:grammar/digits?length={USERID_LENGTH} "> ’; $USERPWD_GRAMMAR=src=builtin:grammar/digits?length={USERPWD_LENGTH }"> ’; ?>

Integrate into Application Template Framework <?php include "includes/class.FastTemplate.php"; include "includes/common.php"; include "includes/functions.php"; include "includes/abstractdatabase.php"; # to have language specific prompts, and grammars include (RESOURCES_DIR. "/login_". LANGUAGE. ".php"); $db = new db(); $db->open(DATABASE, HOST, USER, PASSWORD); # create a new query object $q = new query($db); Common Include files Configurations Database Abstract

Apply Business Logic # any thing that you want to do at the beginning of the page common all pages. pageStart(); # don't really need to declare as global since there are # no functions using $tpl global $tpl; # initialize FastTemplace class $tpl = new FastTemplate(TEMPLATE_DIR); $tpl->define(array("main" => "main.tpl", "login" => "login.tpl")); $tpl->assign(array("USERID_LENGTH" => LOGIN_ID_LENGTH, "USERPWD_LENGTH" => LOGIN_PASSWORD_LENGTH, "USERID_PROMPT" => $USERID_PROMPT, "USERPWD_PROMPT" => $USERPWD_PROMPT, "LOGIN_GRAMMAR" => createLoginGrammar(LOGIN_ID_LENGTH), "PASSWORD_GRAMMAR" => createPasswordGrammar(LOGIN_PASSWORD_LENGTH))); template mappings Variables substitution

Apply Business Logic cont. # doing a search and replace here # variable CONTENT will get the value of the list template after the search and replace $tpl->parse("CONTENT", "login"); # variable MAIN will get the value of the main template # NOTE how the CONTENT variable assigned in the previous instruction gets replaced in the template. $tpl->parse("MAIN", "main"); #print out the last variable: MAIN $tpl->FastPrint(); # any thing that you want to do at the end of the page common to # all pages pageEnd();

Unit Testing via browser Login.php

VoiceXML Application Tools BeVocal Café, BeVocal, Inc. – WebSphere Voice Server SDK, IBM Corp. – Mobile ADK, Motorola, Inc. – V-Builder, Nuances Communication – Tellme Studio, Tellme Networks, Inc – VoiceGenie Dev. Workshop – voxeo community, voxeo Corporation –

Application Tools References Apache Software Foundation – VoiceXML Forum – IBM VoiceXML Resources – PHP – mySQL –