Brooktree HDSL Channel Unit is part of total HDSL solution, includes point-to-multipoint transmission for new HDSL market applications.

SAN DIEGO--(BUSINESS WIRE)--March 6, 1995--Brooktree Corp. (NASDAQ:BTRE) Monday announced an HDSL (High Bit Rate Digital Subscriber Loop) Channel Unit that is the first to include point-to-multipoint transmission capability for such emerging HDSL applications as fractional T1/E1 services or voice pair gain systems.

It is part of a complete multichip HDSL solution from Brooktree that is the only one of its kind to provide the full range of HDSL functionality, all the way from T1/E1 data format conversion to HDSL's sophisticated echo cancellation and line equalization processes.

HDSL technology currently provides the quickest and most efficient means for telephone companies and other telecommunications providers around the world to upgrade standard voice-grade twisted-pair copper wire for advanced, higher-rate data services. With the introduction of Brooktree's Bt8953A, HDSL technology can be used to provision advanced services or voice telephone service even more efficiently by allowing up to three physically disparate locations to be connected from a single central office terminal. For instance, HDSL solutions with the Bt8953A Channel Unit in voice pair gain systems can be used to hook up three locations, each with a single pair carrying up to 18 voice conversations rather than two. Grooming functions inside the Bt8953A are used to reconstruct a single 2Mbps PCM data stream with composite signaling data in the appropriate time slot.

The Bt8953A Channel Unit is used to interface the Brooktree's Bt8952 HDSL transceiver to the company's full line of T1/E1 framers, and performs all tasks related to the composition of an HDSL frame, which consists of the payload data and other overhead bits for error control, EOC and link monitoring. The 5-volt Bt8953 provides one transmitter per loop for converting the incoming primary rate channel into a choice of two or three HDSL loop channels. It also provides one receiver per loop for combining the incoming HDSL loop channels, recovering the primary rate clock, and separating the channel into the HDSL overhead bits and loop data. Alternative HDSL solutions require that an ASIC be developed to handle these functions.

"Brooktree is the only component vendor with a complete solution for an HDSL transceiver, and the Bt8953A Channel Unit is an important part of that solution," said Ron Cates, senior product manager for the Communications Strategic Business Unit at Brooktree Corp. "By eliminating the need to develop an ASIC for the HDSL frame formation function, the Bt8953A reduces non-recurring costs and time-to-market for HDSL solutions. Plus, it offers the new capability of point-to-multipoint transmission, which means that HDSL technology can now be used much more effectively in such new HDSL applications as fractional T1/E1 services or voice pair gain circuits."

HDSL technology uses sophisticated adaptive equalization techniques to take voice-grade twisted copper pairs and boost them from standard 4kHz voice signal rates to 2.048Mbps data rates without the need for expensive line conditioning and repeaters. Telephone companies simply connect one HDSL transceiver at the central office and a second at or near the customer premises, and HDSL technology then compensates for the phase and amplitude distortion associated with achieving the higher transmission rates. This allows telephone companies to very quickly and efficiently provision a variety of advanced services including Primary Rate ISDN, leased T1/E1 lines, fractional T1, SMDS and Frame Relay.

The Bt8953A Channel Unit performs all standard HDSL frame formation functions, including stuff quat timing synchronization in compliance with ETSI and ANSI standards. It also contains all necessary loopbacks at the PCM and HDSL interface to allow for failure isolation through software control. A Mulitframe Output Transmission feature for PCM bus masters allows direct interfacing to the PCM time slot interchange bus, and the Bt8953A has data link support for the last 40 Z bits so users can have a supplemental embedded operations channel. Additionally, the Bt8953A supports JTAG testability and includes significantly more functionality in a smaller, more cost-effective package than its predecessor, the Bt8953, which was introduced in February 1994.

A complete HDSL solution can be generated by using the Bt8953A Channel Unit with Brooktree's Bt8952 HDSL transceiver, Bt8920 analog-to-digital converter and a choice of either the Bt8360 or Bt8510 T1/E1 framers. Brooktree leads the market in providing all of the necessary functionality for a complete HDSL solution, and continues to move toward the higher levels of HDSL integration that will be required for single-chip solutions expected in 1996.

The Bt8953A Channel Unit will be available in sample quantities in the spring of 1995, with volume production scheduled in the fall. The device is packaged in a 68-pin PLCC surface-mount package, and uses CMOS process technology. It is priced at $55 each in sample quantities, and will have lower unit pricing in volume quantities.

Customers interested in more information about the Bt8953A or Brooktree's other communications products should contact the Applications Hotline at 1-800-2BT-APPS.

Brooktree Corporation designs and markets high-performance digital and mixed-signal integrated circuits for computer graphics, multimedia and communications applications. The company, which has its headquarters in San Diego, employs more than 575 people worldwide. Revenues for the fiscal year ended Sept. 24, 1994 were $109 million. Brooktree stock is traded on the NASDAQ National Market System under the Symbol BTRE.

More information on Brooktree Corp. is available from the company's SEC filings, or by contacting the company directly.

CONTACT: Brooktree Corp., San Diego, Calif.

Bill Berridge/Karen Paulovich, 619/535-3275 or -3516

or

The Benjamin Group, Irvine, Calif.

Carolyn Fromm/Marissa Jabczenski, 714/753-0755