ADTRAN Unveils HDSL Loop Support System System Provides High-Capacity Circuit Back-Up.

HUNTSVILLE, Ala.--(BUSINESS WIRE)--Feb. 17, 1998--ADTRAN, Inc. (NASDAQ:ADTN), a leader in transmission products for high-speed digital communications (www.adtran.com), today announced a Loop Support System (LSS) that can detect and switch a failing HDSL T1 circuit to a back-up circuit. The new technology provides a way for telecom carriers to meet the increasingly tough requirements of their customers' Service Level Agreements (SLAs).

The ADTRAN HDSL 1:1 LSS employs both central office and terminating end equipment to deliver a DS-1 channel to a customer over a standard four-wire circuit. The system continuously monitors the main and auxiliary circuits to ensure circuit integrity. If the LSS detects a loss of signal during its routine, the signal is switched to a back-up circuit -- often before a customer even realizes that a failure has occurred.

"Network downtime has become a significant component of most service level agreements these days," said Tom Stanton, vice president of Telco Marketing for ADTRAN. "Our Loop Support System can help carriers meet their network availability commitments and greatly enhance the reliability of their service."

Without a loop support system, Stanton noted, a carrier would have to realize that a failure had occurred either by customer complaint or by alarm monitoring, and then dispatch a service technician to the central office, where the technician would have to locate the problem and physically disconnect the old circuit and reconnect the new one. This labor-and time-intensive process could easily take an hour or more. During that time, the customer's circuit would be out of operation.

The LSS allows a carrier to test and, if necessary, replace a non-active or failed circuit component without affecting the active circuit. In addition, the two circuits, the main and the auxiliary, can be utilized as independent HDSL circuits, if needed. In the central office, ADTRAN's LSS is designed to operate in an ADTRAN E220 RP shelf or any compatible 220 Mechanics Office Repeater Bay. ADTRAN also plans to offer LSS solutions in other Office Repeater Bay mechanics such as the CI WesCom 3192 or AT&T DDM. At the remote site, the LSS solution is a T200 mechanics HTU-R that is housed in ADTRAN Dual T200 Standalone LSS housing. For extended range HDSL applications, ADTRAN's products are fully compatible with its HRE products.

With an estimated average annual growth of 40 to 60 percent, HDSL has become a cornerstone in most carrier's T1 offerings, Stanton pointed out. To protect that offering -- and the revenue it generates -- more and more carriers are looking for a loop support approach. Established in 1985, ADTRAN is a leading provider of total system solutions for delivering today's digital transmission technologies over existing telecommunications infrastructures. The company is best-known for developing cost-effective, high-performance equipment that transforms copper wire local loops into high-speed digital networks. The ISO 9001 company is a top supplier of DDS, ISDN, Frame Relay, T1/FT1 and HDSL products. ADTRAN customers include the Regional Bell Operating Companies (RBOCs) and many of the more than 1,300 independent Telcos in the United States. ADTRAN also designs and manufactures products for private end-users in the customer premise equipment (CPE) market. For more information, contact the company at 1 [phone] or via email at [e-mail]. On the web, go to www.adtran.com .

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