ZyXEL INTRODUCES ZyCELLULAR FOR CELLULAR NETWORKS 

ZyCellular Incorporates Unique Data Pump That Makes it the Only Modem to
Send/Receive High Speed Synchronous Transmissions

PC Expo '93, New York, NY, June 29, 1993 -- ZyXEL, a leading supplier of
high-speed fax modems and compatible products, today introduced
ZyCellular, a high-speed cellular modem that provides users with access to
cellular lines with data transfer rates of up to CELL 14.4Kbps on clear
line conditions and CELL 9.6Kbps in typical cellular line conditions. The
modem will be available in the third quarter of 1993.

High Performance Cellular Data Communications

ZyCellular incorporates the features and performance of ZyXEL's high speed
modems with advanced cellular capabilities, overcoming many of the
imperfections of the cellular channel, including handoff and power change
problems. The ZyCellular is available with ZyXEL's new light weight and
portable modem and are ideal for use in either a mobile unit or on a
desktop.

As a remote user moves from one cell to another, ZyCellular utilizes a fast
synchronization immediately after detecting a handoff or power level
change, enabling it to hold connections. The ZyCellular determines the
optimal connection speed given the unpredictable cellular line condition
and dynamically adjusts the connection speed to increase the reliability
of the connection.

ZyXEL's cellular modem also utilizes V.42 error control with selective
reject, which increases throughput by allowing the modem to handle
frequent block errors maintaining high throughput under severe line
conditions.

Reliability

"ZyXEL's ZyCellular has been specifically developed to prevail over
limitations inherent in cellular communication," said Gordon Yang, ZyXEL's
Vice President Engineering. "We have designed a data pump that strengthens
the physical layer of the cellular network to greatly reduce the modem's
actual bit error rate under severe channel conditions."

The ZyCellular incorporates six unique protocols, designed especially for
cellular networks, to provide error correction and enhanced throughput
with low bit error rates over cellular networks. ZyXEL's six proprietary
technologies include:

1. Fast Re-Synchronization (FRS) of the modem after cell hand-off and power
level changes;

2. Cellular Forward Error Correction (CFEC) to correct high fading errors;

3. Dynamic Cellular Speed Selection (DCSS) to dynamically select the best
operating speed and mode, minimizing errors while maximizing throughput;

4. Automatic Feature Selection (AFS) to select the best error control
method for the prevailing line conditions;

5. Automatic Transfer Power Adjustment (ATPA) probes the line during
handshake and automatically adjusts transmission levels to achieve the
highest signal to noise ratio before entering the data state; and,

6. Reliable Handshake Enhancements (RHE) detect noise impairments which can
add to the initial connection line. If noise is not detected, the
connection is made immediately. If sufficient noise is detected, the modem
will handshake reliably within 30 seconds.

"The cellular environment can change rapidly," explained Yang. "A protocol
such as MNP 10, the current standard among cellular modems, is not as
effective because it must receive several error blocks before any
corrective action is taken. By the time a MNP 10 modem reacts, the error
condition may have already disappeared. To increase reliability in the
cellular environment, we choose to design and implement our own protocols,
which enhance the reliability and performance of cellular links."

Dual Functionality

The ZyCellular has dual functionality for both land and cellular
communications, automatically verifying if the target modem has cellular
capability or not. The ZyCellular comes with an array of standard features
that include auto fall-forward and fall-back, call-back security and
password protection, Caller ID, voice capability, multi-level security,
distinctive ring, remote configuration and the ability to upgrade by
firmware.

Operating in synchronous environments and applications, the ZyCellular
maintains 9600bps connections over any cellular network. It can be
connected to any notebook, laptop, palm top or personal computer, and
works in MS/DOS, Windows, OS/2, Macintosh, and UNIX environments.

The cellular option provides nine cellular-specific communication modes,
ranging from CELL 14,400 to 2400C. The modem supports 14.4Kbps on clear
line conditions as well as all lower speeds and works in synchronous and
asynchronous mode.

For land communications, the ZyCellular fax/modem runs at speeds of
16.8Kbps on regular dial-up or leased lines. ZyXEL high-speed modems with
voice deliver a wide range of CCITT standards that support a host of
protocols including V.32bis, V.32, V.23, V.22bis, V.22/BELL 212A,
V.21/BELL 103 and EIA Class 2 Group 3 V.17-14.4Kbps send and receive fax
capabilities for universal connectivity. They support industry standard AT
Command Set and V.25bis autodial thus ensuring compatibility with most
popular communication and fax software.

Company Background

ZyXEL is headquartered in Anaheim, California. The company is a leading
supplier of high-speed fax/modems with voice and compatible products
including: V.32bis/V.42bis modem/fax, the fastest available for ordinary
telephone lines. Since its inception, ZyXEL has acquired a reputation as
the price/performance supplier by providing high quality products at
affordable prices.

ZyXEL, 4920 E. La Palma Ave, Anaheim, CA 92807
714-693-0808,   Fax: 714-693-8811,   BBS: 714-693-0762

==========================================================
From the America Online -- New Product Information Service
==========================================================
This information was processed from data provided by the
above mentioned company. For additional details, contact 
the company at the address or telephone number indicated.
==========================================================
All submissions for this service should be addressed to:
BAKER ENTERPRISES, 20 Ferro Dr, Sewell, NJ 08080 U.S.A.
Email:  RBakerPC  (AOL),   rbakerpc@aol.com  (Internet)
==========================================================
