Brochure Copy: "Amati ADSL "
for Amati Communications Corporation
Author: Ken Eklund



High Speed
Transfer of
and Data
over copper wire.

<Amati logo>

[inside: left page]

8 Mbps over copper wire

Making today's telephone network the
high-speed data highway of tomorrow

As demand grows for high-speed video and data services to home and office, connection services contemplate future high-capacity networks such as Fiber To The Home (FTTH), Hybrid Fiber Coax (HFC), and Fiber To The Curb (FTTC) and Fiber To The Basement (FTTB) schemes. In truth, however, the costs of digging trenches and stringing cable, especially in the "last mile" before the subscriber, are proving prohibitive. Service providers need a lower cost alternative that uses in part the vast copper network now in place.

Asymmetric Digital Subscriber Line (ADSL) technology offers such an alternative — bandwidth capability over the existing network sufficient to meet the demands of any new broadband service. ADSL offers greater bandwidth per customer than dial-up services or ISDN. Enhanced by Discrete Multi-Tone (DMT) technology, ADSL permits transmission of digital information at rates up to 8 Mbps at distances up to 18,000 feet of single-pair copper wire. Since most subscribers in a typical network are connected within 18,000 feet, a provider with ASDL can offer service to most customers with no change to the physical network.

DMT and Amati
If ADSL can offer broadband service on existing copper networks, why hasn't it been widely implemented? Simply, because of real-world factors — such as long distances to some subscribers and noisy plant in some loops. Twisted-pair copper wire was originally intended to transport analog signals at frequencies less than 4 Khz. As bandwidth demand increases, limitations in the subscriber loop become apparent — so much so that attempting to move digital dataforms at rates up to 8 Mbps would seem to be impossible.

Discrete Multi-Tone (DMT) modulation technology solves this real-world problem by shaping the information flow to the optimum transport characteristics of the media. Simply put, DMT very precisely measures a series of tones transmitted across the copper loop. It then uses these tones as digital carriers, assigning bits per tone carrier according to its measured carrying capacity.

Amati has championed DMT technology to answer these real world concerns: longer distances (to 18,000 feet); highest simultaneous data rates (downstream and upstream); most reliable design (despite noise and plant problems). This is why the T1/E1, ANSI and ETSI committees have all chosen Amati's implementation of DMT as the accepted standard for ADSL.

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Historically, Amati Communications Corporation has led the way in developing, implementing and proving DMT in the real world. Key to implementing DMT successfully: designs that use very high speed Digital Signal Processing (DSP) techniques and circuits. As more and more DSP functions are integrated into custom chips, both the cost and capability of DMT continue to improve.

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ADSL Applications:
accessing video and the Internet.

The current market for high-speed data transmission to home and office includes:


More applications can be expected to develop as high-speed access to data becomes more common.

These applications all have a consistent mode of operation: data flows downstream to the subscriber at rates from 1.5 to 8 Mbps, while response or control information is sent back to the service provider at rates from 9.6 to 640 Kbps. By using DMT with ADSL, Amati can achieve this mode of operation on existing copper networks.

Using the MPEG2 standard, video (movies, catalogs or live broadcast) can be converted into digital information. But without sufficient bandwidth — capable of a transport rate of at least 6 Mbps — digitized video loses content and risks becoming visually unacceptable. To transmit these video applications over existing copper networks, ADSL is required — and as distances grow, DMT becomes necessary.

Internet Access
Although interest in the Internet grows daily, the slow rate of existing dial-up analog technology frustrates users. Even relatively small video, graphic and audio files slow response to an unacceptable level. Although modem-to-cable is discussed as a higher speed alternative, this would require new network connections. Also, because most cable networks have shared-delivery systems, a full complement of subscribers could drop throughput to undesirable levels.

By comparison, ADSL uses the existing copper network that connects homes in most countries; it requires no new networking or connections. ADSL accepts the data protocols common to LAN-based networks. And ADSL, using DMT, can provide Internet ready (1.5 Mbps downstream/160 Kbps upstream) service to subscribers up to 18,000 feet from a central node, with no additional installation support.

[inside: right page]

very fast copper.

Amati's Very High Speed Digital Subscriber Line (VDSL) is a future technology designed to complement ADSL: enabling much higher data rates (up to 51 Mbps) over shorter distances of existing copper network. VDSL uses symmetrical as well as asymmetrical data transmission protocols.

VDSL foresees a network architecture that moves high-bandwidth (typically, optical fiber) data distribution nodes closer to the subscriber — to a neighborhood, to the curb, to the basement of a complex, or within a business park. VDSL then provides very high-speed data transport to the subscriber, over existing copper at distances of 3300 feet (1 Km) or less. Amati is developing the VDSL technology as a high-performance, low-cost, integrated solution for the high-bandwidth networks of the future.

The bandwidth carried to the user depends on the exact distance. In effect, the VDSL technology establishes a sliding scale of data rate versus distance, automatically enabling the best throughput rate for each connected line.

VDSL and DMT: Multiple Video
As it does for ADSL, DMT modulation also enhances VDSL technology. Amati has developed a symmetrical data interface especially for VDSL, enabling data throughput at up to 50 Mbps (2 x 25 Mbps) per channel at a distance of 1650 feet (500 m), or 25 (2 x 12.5 Mbps) Mbps at 3300 feet (1 Km). VDSL will open up the local loop into a source of very high bandwidth data — such as multiple broadcast video — for the subscriber.

The Future of Amati

Amati Communications Corporation focuses on continued development of its DMT technology, and its integration into our line of ADSL and VDSL system-level solutions. Our products will include high-speed integrated circuits, ADSL and VDSL transceiver and receiver modules, and system-level products for connecting ATM, frame relay, TCP/IP, and other existing and future digital services to ADSL and VDSL transmission lines. For more information about our company, our products, or the future of digital telephony, please contact us.

[back cover]

System-Level Solutions
by Amati Communications.

Amati Communications Corporation develops advanced equipment that utilizes Discrete Multi-Tone (DMT) technology to transmit digital video, voice and data over copper wire or coaxial media at distances up to 18,000 feet (5 Km), and at rates of 6 Mbps and more. Amati's business focus is the integration of DMT technology into Amati's line of Asymmetric Digital Subscriber Line (ADSL) and Very High Speed Digital Subscriber Line (VDSL) products. By enabling broadband data and video access over existing networks, Amati's systems aim to solve the "last mile" cable problem for network users and connection service providers.

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