Telebyte Introduces Low Cost Local Loop Simulator for DSL Testing.

GREENLAWN, N.Y.--(BUSINESS WIRE)--Sept. 28, 1999--

New Model 454 Precisely Simulates Frequency Response for Local

Loop Lengths up to 18,500 Feet; Simplifies Testing of ASDL as

well as HDSL, T1 and E1 Modems

Telebyte Inc. (OTC BB: TBTI), a leading manufacturer of Digital Subscriber Line (DSL) test equipment announced the introduction of the Model 454 Local Loop Simulator. Model 454 is a compact laboratory and/or production test unit that precisely simulates the frequency response of the local loop used by telephone companies (Telcos). The unit presents an accurate simulation of both the amplitude and propagation delay characteristics of a single, 26 AWG (0.4mm) telephone pair at frequencies extending from DC up to 1.5 MHz. This is precisely the frequency range of interest for ADSL technology, used to provide high speed Internet access over the local loop.

"This unit is a welcome solution to the problem of testing the wide variety of Asymmetric Digital Subscriber Line (ADSL) modems that are being manufactured to provide high speed Internet access at T1/E1 speeds," stated Telebyte President Michael Breneisen. "Model 454 delivers a low cost, a convenient form factor, and is extremely accurate in simulating local loop characteristics. In addition to being ideal for testing ADSL modems on the production line, it also offers the ability to test modems using the more mature High data rate Digital Subscriber Line (HDSL) technology, and T1 and E1 applications," furthered Breneisen. While well suited to the production line, Model 454 can be employed as an engineering tool in the developmental laboratory as well, ensuring product design will live up to performance expectations in the field.

Model 454 emulates local loops extending up to a maximum of 18,500 feet--a distance equivalent to the furthest subscriber connected to a Telco central office. For enhanced flexibility, Model 454 is comprised of separate sections that can individually simulate the characteristics of cable lengths of 500 feet, 1,000 feet, 2,000 feet and 3,000 feet. These sections can be connected in any combination to allow simulation in 500-foot increments of any cable length up to 18,500 feet. Tandem connection is accomplished by pressing front panel "push button" switches. Additionally, by employing multiple Model 454s, ADSL modems can be tested in configurations with bridge taps.

Model 454 is totally passive, requiring absolutely no AC power, making it a very portable solution. This also translates to a long lifetime and high reliability--features that are essential given the harsh production environments in which the unit will typically be installed. Model 454 is equipped with two bi-directional ports, supporting both 400 Volt levels and 120 mA DC current. Consequently, it is transparent to Loop Current and Ringing voltage.

"Model 454 is very different from other line simulators in that it allows for the testing of telecommunications equipment utilizing frequencies well above the voice band," said Breneisen. We're excited about this product because its broad frequency range and extended distance simulation specifications are more than sufficient to cover high speed technologies such as ASDL. Model 454 should be a very attractive and cost efficient solution for our customers." -0-

Model 454 Basic Specifications

Equivalent Wire AWG:        26 AWG PIC Cable at +70(degree) F
                         per AT&T reference publication 62310

Length Increments:            Feet            Kilometers
                              ----            ----------
                               500                  .15
                              1000                  .30
                              2000                  .60
                              3000                  .90 (five sections)

Simulation Capability:   0 to 18.5Kft in 500' increments
                         ANSI T1.601 Loop No.7:(13,500 feet, 26 AWG)
                         Mid CSA Loop:   (6000 feet, 26 AWG)
                         CSA Loop  No.6: (9000 feet, 26 AWG)

Rated Frequency Ranges:   DC to 1.5 MHz

Attenuation Accuracy:   +/- 5% +/- 0.5dB

Maximum Operating Level:    Maximum Peak Voltage 500V (DC + Peak AC)
                            Maximum Continuous Current of 120 mA DC

Size:                       6.0"H x 12.7"W x 13.5"D

Weight:                                       12 lb.

Suggested List Price:                       $1595.00

Telebyte, Inc. is a leading manufacturer and reseller of data communications equipment for fiber and copper networks headquartered in Greenlawn, New York. Telebyte supports a wide range of communications solutions and services including Internet and DSL Products, LAN Tranceivers, Interface Converters, Short Haul Modems, Fiber Optic Products, Test Equipment, Multiplexers and Lightning Protection. Additional information on Telebyte Inc. can be found at www.telebyteusa.com.