For many potential cellular phone customers, prepayment is the only way to get a mobile phone. Credit or income deficiencies will cause cellular service providers to deny an estimated 28 million Americans a cellular phone by the year 2000, according to Telemac's reports.
Developers at Telemac evaluated Windows NT as the platform for a new telephony application to provide an innovative cellular service, debit phones, for customers with poor or no credit history. Debit phones let service providers tap into the credit-risk market and avoid bad debts. The programming team at Telemac, including brothers Chris and Greg McGregor, had used Unixware on previous projects. "We had a long debate about Unix or NT for this new application," said Greg, Telemac's director of software planning. The team concluded that Unix's advantage was familiarity, and this appeal couldn't match NT's available tools and support or lower development costs.
After deciding on NT, Telemac chose APEX Voice Communications's OmniVox for its interactive voice response unit (IVRU) system on the front end. Then Telemac's development team decided that Raima's Velocis Database Server would make its application a ringing success.
Problem and Solution
Telemac's new NT-based Debit Technology provides pay-as-you-go cellular service. The debit phone has a chip that regulates the phone's available air time. A back-end NT-based database server running NT 3.51 is at Telemac's headquarters in Danville, California. A customer calls in to an IVR system and enters a personal identification number (PIN). If the customer has a prepaid calling card or a credit card Telemac's Debit Technology server application gives a code the customer keys into the phone to unlock more calling time.
Telephony is a key component of Telemac's solution. "We had to use the Telephony API (TAPI) to take advantage of the Remote Access Service (RAS) features in Windows 95 and NT," said Greg. "We use TAPI to communicate to cellular phones, process credit cards, and support the native dial-up server under NT and Win95."
Cutting Development Costs
Several key components of the Telemac's Debit Technology application were less expensive for NT than for Unix. For voice processing, Telemac chose OmniVox, a high-level telephony application generator with a drag-and-drop, iconbased interface, and a Dialogic telephony card. Fully configured, OmniVox for Unix costs $8000, compared to $6400 for NT.
"We had one week to get the Debit Technology IVRU shell running," Greg said. So Telemac called on Dialogic, a leading PC telephony voice card manufacturer, to recommend a telephony card and a voice processing development program. "Dialogic recommended OmniVox. OmniVox got us up and running reliably and quickly," he said.
Performance wasn't a problem for Telemac's telephony application. "With voice stuff, the hardware, not the OS or application, does most of the work," Greg said.
The cost of NT vs. Unix also affected decisions about the application's server side. Telemac liked the cost of NT Server, $699, compared to $1695 for Unixware. Only the back-end database server, Raima's Velocis Database Server, costs the same--$8995 for an unlimited client license--for NT and Unix when you run Velocis on a low-end PC.
Choosing a Database Server
Telemac considered Microsoft's SQL Server and Raima's Velocis Database Server for the back-end database server. SQL and Velocis offer similar features: Both are client/server databases, support SQL, include referential integrity and transaction processing, and communicate with the OmniVox application through the Microsoft Open Database Connectivity (ODBC) standard. But Velocis allows higher performance by supporting multiple database architectures.
SQL Server follows the relational databases model. Velocis supports relational joins between records and lets you use network database architecture to connect records. This network architecture refers to a particular model for storing and retrieving records. In this model, which predates relational databases but is still a mainstay of some corporate data repositories, records join directly through pointers, so queries are much faster than with the relational model.
Developers also considered portability because Telemac expects some customers to buy the application and deploy it on Unix. Velocis ports easily to most Unix variants, but SQL Server is NT-only.
A Winning Combination
Three major US cellular carriers recently completed testing Telemac's Debit Technology, and it performed well. Telemac's Debit Technology runs on a Pentium server. As the application's use grows, Telemac will scale up to five Pentium servers running NT and hosting the IVRU application, with a back-end Alpha NT database server.
Telemac uses NT's Perfmon to tune the application and chose the NT File System (NTFS) file structure over the File Allocation Table (FAT) structure. "NTFS offers higher performance and better security than FAT," said John Dismuke, Telemac's director of MIS/communications, who oversees the daily operation of Telemac's Debit Technology.
Telemac has joined NT's features with third-party tools to form a winning combination. By choosing NT, Telemac and other application developers are recognizing NT as a mature operating system.
Please see sidebar "An Interview with Telemac".
Telemac's Debit Technology lets customers dial in to an IVRU system that is connected to a back-end database server to unlock prepaid cellular calling time. Telemac used Dialogic telephony cards and the OmniVox telephony application generator from APEX Voice Communications to develop this application. Raima's Velocis Database Server gave Telemac the flexibility and performance the company needs in its database server.
Telemac's Debit Technology runs on a Pentium server. Telemac plans to scale up to five Pentium servers running NT to host the IVRU application. Telemac will add an Alpha NT database server on the back end.
Greg and Chris McGregor's telephony team developed an NT-based debit cellular service.