Advent Networks and Mitsubishi Corporation Announce Launch of First Commercial Ultraband Service in Japan.

Business Editors/High-Tech Writers

AUSTIN, Texas--(BUSINESS WIRE)--March 24, 2003

Advent Networks(tm), a provider of broadband solutions for cable operators, and Mitsubishi Corporation  (TSE:8058), the exclusive distributor of the Ultraband(tm) system in Japan, today announced that Tokai Broadband Communications (T-com) will be the first cable operator in Japan to commercially deploy Advent's ultra high-speed data system to residential and business customers.

T-com will deploy the Ultraband system in its Atsugi Isehara Cable Network (AIC).

AIC will launch broadband services utilizing Advent's Ultraband system in April in its greater Tokyo network. Initially, AIC will offer guaranteed 10 Mbps transmission speed to home users for 4,980 Yen (US $42) per month. For commercial customers, AIC will offer a service level that guarantees 40 Mbps, which is faster than many fiber-based connections in Japan.

In the competitive Japanese broadband access market, ADSL (12 Mbps), fiber-to-the-home (FTTH, 100 Mbps), and cable modem service (4 Mbps) are offered as best effort services, with broadband providers unable to guarantee bandwidth speeds. In the case of ADSL, bandwidth speed decreases in proportion to the distance between the home and the central office. With the current cable modem service, bandwidth is shared among many subscribers and as a result, download speed slows during busy hours. In the case of FTTH, it is costly to lay new fiber and takes time to deploy.

The Ultraband system solves these problems by creating a new category of broadband service that is not shared, does not have distance limitations, and does not require any changes to the existing cable network.

"The Ultraband system expands the bandwidth of cable networks to meet the growing demand for streaming video, online gaming, video-chat and other new Internet applications," said Tomoya Fujiwara, President of Atsugi Isehara Cable Network. "This enables cable operators to be more competitive against DSL and FTTH."

Advent Networks, AIC and Mitsubishi Corporation began field trials of the Ultraband platform in June 2002 and concluded with customer trials in December 2002. Based on the trial results, over 70% of the trial users stated they are considering or planning to switch to Ultraband service from their existing broadband service.

"The 17% adoption rate of broadband in Japan is higher than US broadband penetration of 15%," remarked Geoff Tudor, CEO of Advent, "so it is natural that Japan will be leading the way with new broadband technologies such as the Ultraband system. We are ecstatic about the product launch and look forward to more deployments in Japan."

Mitsubishi Corporation is planning to introduce the Ultraband system to approximately 300 Japanese CATV operators in Japan. The Ultraband system recently also completed trials with another undisclosed Japanese cable operator.

In addition, the Ultraband system is currently deployed in the cable networks of two of the four largest cable operators in the United States.

About Atsugi Isehara Cable Network Inc.

Atsugi Isehara Cable Network Inc. (AIC) is one of the core companies of the TOKAI Group. TOKAI is one of the leading energy and communication conglomerates in Japan. AIC operates CATV and CATV Internet services in the cities of Atsugi and Isehara, which are located in the greater Tokyo metropolitan area.

About Mitsubishi Corporation

Mitsubishi Corporation is one of the world's most diverse enterprises. Mitsubishi Corporation has decades of experience doing business around the world, experience that has made it more than just a leader in international trade. The company's seven business groups -- New Business Initiatives, IT & Electronics, Energy, Metals, Machinery, Chemicals and Living Essentials -- work closely with clients to develop new business opportunities. Project coordination, sourcing of raw materials, capital investment, and development of sales channels are typical of the ways Mitsubishi Corporation creates value for business partners, customers and shareholders.

About TOKAI CO. Ltd

TOKAI is the one of the largest energy and communication conglomerates in Japan. It is the dominant supplier of LP gas in Japan and at the same time the 4th largest MSO in CATV operations. TOKAI is comprised of approximately 20 group companies all involved in diversified activities from energy, real estate, home security, insurance, EC, ASP, to Internet CATV services. In the field of communications, TOKAI is currently installing an all optical fiber backbone network around the Greater Tokyo area, Shizuoka prefecture and Nagoya area, which will be used to facilitate CATV backbone and Internet services.

About Advent Networks

Based in Austin, Texas, and founded by cable industry professionals, Advent Networks has developed the Ultraband system for the delivery of guaranteed bandwidth over existing cable networks. With scalability up to 40 Mbps for a single user, the Ultraband system represents an evolution in cable access networks -- fiber-like bandwidth to the subscriber without the need for costly plant upgrades. Through this system, operators can offer next-generation packet services that combine video, voice and data into a single, guaranteed IP connection to the customer. Contact Advent Networks at 512/241-8000, 866-2-ADVENT, or via the Web at www.advent.net.

Advent Networks and Ultraband are trademarks of Advent Networks.