ATC Teleports, Inc. Announces Implementation of the World's Largest Asymmetric Satellite Service - Company Business and Marketing

Cambridge Telcom Report, April 17, 2000

10ATC Teleports, Inc., a wholly owned subsidiary of American Tower Corporation (NYSE:AMT), announced Monday that it has successfully completed the implementation of the world's first commercial OC-3 asymmetric satellite service for direct Internet backbone access.

ATC Teleports is currently providing OC-3 service to Embratel - Brazil, the international telecom provider for Brazil, via the Intelsat 805 at 304(Degree) East. With an outbound data delivery rate of 155.5 Mbps and a return rate of 34 Mbps, currently no service provides a larger commercial asymmetric Internet satellite link. Due to ATC Teleports' proprietary design, this service offers the most efficient Internet over satellite service to date with effective IP throughput measured at greater than 99%. The OC-3 connection to Brazil meets ISP requirements in Brazil for both business and home users of the Internet. ATC Teleports is Embratel's single largest provider of international satellite Internet access.

The OC-3 network is incorporated as part of the direct high-speed multiple OC-12 Internet backbone that was developed by ATC Teleports and its partners. The Satellite International Private Line (SIPL) hub for the network is collocated at ATC Teleports' Holmdel, New Jersey facility. This new technology is providing the fastest and most direct service to the U.S. Internet backbone for International ISP's, with only 500 milliseconds of delay. This network connects the customer directly onto the backbone at the teleport, as opposed to utilizing fiber connection from the teleport to a local Internet POP, offering more flexibility in data rates, bypassing the need for local loop connections and greatly reducing the costs for bandwidth. ATC Teleports has a second SIPL hub at the Glenwood, New Jersey facility, offering customers a wide range of satellite options. IP Platforms are available at the Dallas and Washington DC facilities.

David Kagan, President and CEO of ATC Teleports stated, "By utilizing proprietary network technology, designed in-house, ATC was able to achieve a state-of-the-art data rate per unit of satellite space segment. We believe that, the OC-3 service offers the most effective Internet throughput, unsurpassed by any current operational satellite asymmetric design. The international Internet market place is expanding at a rate that demands the highest bandwidth and the latest in technological accomplishments. We are extremely proud of our engineering and operations departments that made it possible to achieve the first successful asymmetric OC-3 service."

ATC Teleports, Inc. is a leading provider of domestic and international satellite and IP network services. Giving effect to pending transactions, the company owns and operates more than 160 antennas accessing most major satellite systems from U.S. teleport locations in Arizona, California, Massachusetts, New Jersey, Texas, Washington state and Washington DC. ATC Teleports supplies terrestrial connections to major points of presence (POPs), co-location facilities and switching centers. It has 24x7 Technical Operations Centers at all major facilities. The teleports offer comprehensive networked solutions, including complete engineering, management and technical assistance for full-time and occasional-use video, Internet, data, voice as well as maritime applications. For more information, contact www.atcteleports.com.

American Tower is the leading independent owner operator and developer of broadcast and wireless communications sites in North America. Giving effect to pending transactions, American Tower operates approximately 10,400 sites in the United States and Mexico, including approximately 300 broadcast tower sites. Of the 10,400 sites, approximately 9,000 are owned or leased towers and approximately 1,400 are managed and lease/sublease sites. Based in Boston, American Tower has regional hub offices in Boston, Atlanta, Chicago, Houston, San Francisco and Mexico City. For more information about American Tower Corporation visit www.americantower.com.