Aurora's Digital Return Technology Doubles Upstream Cable Bandwidth

CHICAGO - To address the growing need for upstream bandwidth in cable networks, Aurora Networks announced a Universal Digital Return technology that doubles cable return-path capacity by using the recently reclaimed broadcast television spectrum.

By using the 54-88 MHz spectrum once reserved for analog broadcast television, the Universal Digital Return module expands the upstream bandwidth to 5-85 MHz, essentially doubling today's standard North American offering of 5-42 MHz.

Digital return is the only practical way to achieve the high link performance required by a fully loaded 5-85 MHz upstream pass band and utilizing 64-QAM (or the even more efficient 256-QAM) DOCSIS 3.0 upstream bonded channel technology, independent of distances beyond 100 km. Instead of a laser, an analog-to-digital converter undertakes the hard work in digital return technology. Network engineers can easily deal with variations in loading and link distances.

"With the demand for more upstream capacity, Aurora Networks has innovated to cost-effectively remove this bottleneck and still meet the ever-increasing upstream performance requirements," says John Dahlquist, vice president, marketing. "The beauty of digital return technology is the independence of RF loads and required laser performance. Digital return technology provides operators with a cost-effective pathway to meet performance requirements that are currently not achieved by today's upstream analog lasers."

Deploy Today, Upgrade Later
The new return technology simplifies the transition to a higher split return by also supporting today's standard 5-42 MHz return path. The Universal Digital Return module uses a common platform for all band-splits (from 5-42 MHz, to 50 MHz, to 65 MHz and to 85 MHz) and then "personalizes" them for not only the band-split required but also for other features, such as "1-fer" versus "2-fer", data transmission speed and operational modes, according to the specific network requirement. By including all of the required capabilities in one platform, operators may implement those features required to support their current requirements, like 5-42 MHz today, and transition to 5-85 MHz tomorrow by simply changing out the inexpensive personalization module.

The technology also optimizes Fiber Deep (Node plus 0) architecture. Fiber Deep deployments eliminate the need for RF amplifiers, providing huge cost savings for operators. By combining Universal Digital Return with Fiber Deep, operators have a much simpler path to increased bandwidth per subscriber because they only have to upgrade the node. To reach the same outcome with a traditional HFC architecture would require the replacement or upgrade of three to four times as many active devices (nodes and RF amplifiers) without achieving any of the operational savings of a Fiber Deep architecture

Finally, the technology permits more efficient node segmentation. The fastest and easiest way for operators to increase capacity per subscriber is with node segmentation. Because the Universal Digital Return allows up to two unique RF input channels per transmitter, up to 15 wavelengths with CWDM, and up to 40 wavelengths with DWDM, it provides the flexibility for very fiber-efficient node segmentation solutions. In addition, because the technology is SFP-based, the process of wavelength selection, sparing and service restoration is greatly simplified.