Portable Computer and Communications Association Standards Committee defines AT command set for CDPD modems.

SAN JOSE, Calif.--(BUSINESS WIRE)--Dec. 6, 1996--The Portable Computer and Communications Association Standards Committee has passed an extension to PCCA standard STD-101 that defines an AT command set for Cellular Digital Packet Data (CDPD) modems, it was announced Friday by Peter Rysavy, standards committee chairman.

PCCA STD-101 establishes conventions for uniform extension of its own scope and content through Annexes. The new extension, Annex L, permits CDPD wireless modems to be configured in the command mode, defining 44 separate functions that either command the modem or program its registers.

``The PCCA Standards Committee is committed to open standards for the wireless industry, and Annex L is significant milestone,'' Rysavy said.

``STD-101 establishes that wireless modems operate either in a command mode or in a data mode. In the data mode, most CDPD modems today use the Serial Line Internet Protocol (SLIP) to communicate IP datagrams between the mobile computer and the wireless modem.

``In the command mode, for which Annex L provides an enabling interoperability environment, these modems appear similar to landline modems and can now be configured using AT commands. Annex L should be of great significance in CDPD achieving its potential.''

Two important benefits devolve from Annex L for application developers, Rysavy said:

-- It allows TCP/IP stacks to support all CDPD modems complying

with Annex L by using one standard connection script;

-- It allows management and diagnostic utilities to easily support

any CDPD modem that complies with Annex L. Such utilities

today must support different modems by using entirely different

sets of commands.

``Additionally, we expect Annex L to play an important role in the Windows operating environment, for which Microsoft advocates two communications interfaces: Telephony API (TAPI), combined with Unimodem for modem communications, and the Network Driver Interface Specification (NDIS) for network communications,'' he said.

``Annex L is important for both of these interfaces. It enables Microsoft to supply one generic information file for TAPI/Unimodem that will support all CDPD modems complying with Annex L. It also allows the development of a generic wireless NDIS driver for CDPD modems, using Annex L commands to communicate.''

Companies involved in developing the Annex L specification include AT&T Wireless Services, Megahertz, Motorola, PCSI, Sierra Wireless, Telxon and WRQ. Rysavy is a Seattle-area consultant specializing in wireless data communications. He can be reached at [e-mail].

Founded in 1992, the Portable Computing and Communications Association is a nonprofit trade association that focuses on the convergence of the two industries. Its charter is to enable, develop and promote the adoption of software and hardware standards for interoperable mobile computing and communications.

Membership is open to all companies and individuals with an interest in these disciplines. For further information, contact PCCA at 408/338-0924; fax [phone]; or view its Web site: www.outlook.com/pcca .

CONTACT: Portable Computer and Communications Association

Bob Venter, 408/338-0924

or

Victor Wortman Co.

Vic Wortman, 310/393-6281