Telephony? Just Call on NT

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.