NEXTLINK Announces Consecutive Point Broadband Wireless Equipment in Boston and Dallas.

Business Editors/Hi-Tech Writers

MCLEAN, Va.--(BUSINESS WIRE)--May 10, 2000

--Triton Network Systems Invisible Fiber broadband wireless equipment

expected to economically extend NEXTLINK's local fiber networks--

NEXTLINK Communications, Inc. (NASDAQ:NXLK), one of the nation's fastest growing providers of broadband communications services, today announced it is beginning field trials in Boston and Dallas of "consecutive point" broadband wireless technology that is expected to be used to significantly extend NEXTLINK's local fiber networks via "invisible fiber (TM)wireless" rings.

NEXTLINK selected Triton Network Systems, Inc.(TM) (TNS) to participate in the field trials after TNS successfully passed rigorous network testing in NEXTLINK's research lab in Plano, Texas.

In the field tests, Triton Network System's consecutive point equipment is being utilized in varying network environments to evaluate its SONET-like ring-architecture design and integration with NEXTLINK's current fiber-based and broadband wireless networks.

"We expect the use of consecutive point wireless technology to complement our current point-to-point and point-multipoint broadband wireless capabilities and extend the reach of our fiber networks at a fraction of the current construction time and cost," said NEXTLINK Chief Technology Officer, Doug Carter. "We've been pleased with our lab results using Triton Network System's 'Consecutive Point' broadband wireless equipment. And because the technology is SONET protected it is extremely stable and we expect it to be relatively easy to integrate into NEXTLINK's existing fiber and broadband wireless networks."

Consecutive point broadband wireless technology essentially forms wireless sub-rings within the 20-40 square mile area that comprises the local network of most metropolitan areas.

Additionally, in the unlikely event of a wireless link failure, the consecutive point Invisible Fiber ring continues without service interruption as the traffic - similar to the operation of a SONET fiber network - is automatically re-routed in the other direction within the ring. NEXTLINK intends to use these wireless technology to extend the rings of it's local fiber network.

Then the company intends to make the final "golden mile" connection directly to a customer's building via a combination of facilities-based fiber and broadband wireless or facilities based digital subscriber line (DSL) connections.

Another expected advantage of the consecutive point broadband wireless technology is its software capabilities that will allow the NEXTLINK network operations center to simultaneously view the company's fiber and broadband wireless networks in real time without the need for supplementary connections or equipment.

"Working with the NEXTLINK team on these trials and first office applications has given us the opportunity to demonstrate the advantages of our Invisible Fiber units deployed in consecutive point networks," said Triton Network Systems President and CEO, Skip Speaks. "Triton Network Systems' broadband fixed wireless access products are expected to enable NEXTLINK to extend the reach of their fiber networks, to deliver carrier class quality and to maximize the use of their capital."

NEXTLINK has previously announced its selection of Nortel Networks to provide broadband wireless, point-to-multipoint access equipment. The company expects to utilize additional broadband wireless vendors in its networks in the future. NEXTLINK plans to deploy broadband wireless networks to a total of 25 U.S. markets by the end of 2000.

About Triton Network Systems

Triton Network Systems, Inc. provides broadband wireless equipment that enables communications service providers to deliver high-speed, cost-effective voice, video, and data services to their customers.

About NEXTLINK

NEXTLINK Communications, Inc., a McLean, VA-based company, provides high quality, broadband communications services to businesses over fiber optic and broadband wireless facilities across the United States. NEXTLINK currently provides service in 49 markets. The company is the largest holder of broadband fixed wireless spectrum in North America, with licenses covering 95 percent of the population in the top 30 markets in the United States.

NEXTLINK plans to use wireless capabilities to complement and extend the reach of its local fiber optic networks in the markets in which NEXTLINK has spectrum. Additionally, NEXTLINK is acquiring exclusive rights to use certain fibers and a conduit throughout a 16,000-mile high-speed, IP-centric fiber optic backbone network that will connect over 50 cities in the United States and Canada.

The network is expected to be finished in 2001, with NEXTLINK turning on segments of the network during 2000. Through this unrivaled collection of facilities, NEXTLINK will provide integrated, end-to-end telecommunications solutions to its customers. For more information, visit http://www.nextlink.com.

On January 10, 2000, NEXTLINK and Concentric Network Corporation announced an agreement to combine the companies. The transaction is expected to close in the second quarter of this year. Concentric provides complete Internet business solutions for small- and medium-sized enterprises, including DSL access, Web hosting and e-commerce.

Concentric also offers data center services, virtual private networks, dedicated access, and application infrastructure services for delivering applications over the Internet or a virtual private network.

The statements contained in this release which are not historical facts are "forward-looking statements" (as such term is defined in the Private Securities Litigation Reform Act of 1995).

These statements include those describing NEXTLINK's testing of the consecutive point technology and it's expected benefits, as well as planned network launches, will rollout of its broadband wireless and other products and services, and the timing and potential impact of the Concentric transaction.

Management wishes to caution the reader that these forward-looking statements are only predictions and are subject to risks and uncertainties and actual results may differ materially from those indicated in the forward-looking statements as a result of a number of factors.

These factors include, but are not limited to, NEXTLINK's ability to design and construct fiber optic networks, install cable and facilities, including switching electronics, to develop, install and provision LMDS equipment and interconnect that equipment with NEXTLINK's fiber networks and connect the networks, including LMDS equipment, to customers and on satisfactory terms and conditions, and risks related to NEXTLINK's national network strategy.