NEXTLINK Selects Nortel Networks for Broadband Fixed-Wireless Equipment.

Business Editors/Hi-Tech Writers

Broadband Wireless World Forum

SAN FRANCISCO--(BUSINESS WIRE)--March 15, 2000

McLean, Virginia-based NEXTLINK Communications, Inc. (NASDAQ:NXLK), a fast growing provider of broadband communications services and the nation's largest holder of broadband wireless spectrum, announced today it has selected Nortel Networks(a) (NYSE/TSE: NT) to provide broadband wireless, point-to-multipoint access equipment.

The announcement was made at the Broadband Wireless World Forum in San Francisco and is subject to the finalization of a contract between the two companies.

The selection allows for NEXTLINK to purchase the Nortel Networks' Reunion(a) ATM (asynchronous transfer mode)-based point-to-multipoint FDMA (frequency division multiple access) and TDMA (time division multiple access) solution as well as Nortel Networks' point-to-point radios.

NEXTLINK and Nortel Networks also plan to extend their relationship in a cooperative technology initiative designed to expand the use of broadband wireless in a wide area IP (Internet Protocol) end-to-end network between several major metropolitan areas. This initiative is an important step in creating a virtual Ethernet network that will enable NEXTLINK to capitalize on the explosion in data services.

"We're pleased to make this initial choice in our broadband wireless vendor strategy," said NEXTLINK Chief Technology Officer Doug Carter. "We have a long-standing and positive relationship with Nortel Networks and we are confident they can play a key role in the deployment plan for our wireless solution that will allow us to deploy broadband direct connections to our customers.

"As we have said all along, we intend to use a multi-vendor strategy for our broadband wireless networks and we expect to award additional contracts at the appropriate time."

NEXTLINK will use the equipment in a number of markets scheduled for commercial broadband wireless deployment this year. NEXTLINK is currently using broadband wireless service to link customers to its local fiber optic rings in Dallas and Los Angeles. Nextlink plans to commercially launch broadband wireless networks in 25 U.S. markets by the end of this year.

"As a fast-growing, fast-moving company, Nortel Networks is excited about working with NEXTLINK, the largest LMDS spectrum holder in the US, in creating new end-to-end network solutions," said Steve Schilling, president, access networks, Nortel Networks. "With our leadership position in high-speed access, we enjoy helping our customers create significant competitive advantage in local access service delivery."

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.

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. For more information, visit http://www.nextlink.com.

Nortel Networks is a global leader in telephony, data, eBusiness, and wireless solutions for the Internet. The Company had 1999 U.S. GAAP revenues of US$21.3 billion and serves carrier, service provider and enterprise customers globally.

Today, Nortel Networks is creating a high-performance Internet that is more reliable and faster than ever before. It is redefining the economics and quality of networking and the Internet through Unified Networks(a) that promise a new era of collaboration, communications and commerce. For more information visit www.nortelnetworks.com.

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 network, the timing of deployment of LMDS equipment and the structure 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, those describing Concentric's enhanced product and service offerings, the competitive capabilities and potential synergeries of the combined companies, 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 the Company's fiber networks and connect the networks, including LMDS equipment to customers and on satisfactory terms and conditions, and certain risks related to the Company's national network strategy.

Additional factors include the ability of NEXTLINK and Concentric to successfully integrate their operations, products and services, and to timely obtain the regulatory and stockholder approvals that are conditions to closing the proposed transaction.

(a) Nortel Networks, Unified Networks and Reunion are trademarks of Nortel Networks.