Axcera Demonstrates Distributed Transmission and RF Watermark Technologies at ATSC Annual Meeting

Technology Leader Presents Another First with Operational Demo of
DTV Enhancements Undergoing ATSC Approval

Lawrence, Pa. March 25, 2003 – Axcera, a leading supplier of high-quality equipment and systems for the television broadcast and broadband wireless access industries, was first to demonstrate two important new digital television technologies at the annual meeting of the Advanced Television Systems Committee March 11 in Washington, D.C.

With the DTV rollout in full swing, broadcasters are beginning to examine the challenge of replicating existing analog service areas with digital signals. This can be difficult, especially with challenging terrain or when UHF DTV channels must replicate analog VHF coverage. Distributed Transmission, which is a Candidate Standard undergoing ATSC consideration, addresses this problem by allowing the use of multiple on-channel transmitters to target population centers and improve coverage in weak signal or shadowed areas, without the need for additional channels and translators.

Highlighting its engineering leadership, Axcera showed the DXA2B Distributed Transmission Adaptor providing SMPTE 310 streams to two “slave” DT2B modulators. The outputs of the slave modulators were combined and fed to both a legacy receiver and an advanced receiver prototype, simulating reception in signal overlap areas. Axcera is the only supplier to implement an operational Distributed Transmission Network using the ATSC signal. Penn State's WPSX-DT has chosen Axcera to implement this technology in central Pennsylvania.

Associated with the distributed transmission concept, RF Watermark Technology inserts a low-amplitude symbol sequence into the 8VSB signal to identify the digital transmitter broadcasting the signal. The RF Watermark system was developed to allow field test equipment to identify which slave transmitters are being received, and to detect the separate impulse responses of each slave transmitter at a particular receiving location. The RF Watermark may also be used to identify transmitters that are well below normal reception threshold, for example, from a source of co-channel interference.

Broadcast consultant S. Merrill Weiss, of The Merrill Weiss Group, who developed the underlying principles of Distributed Transmission, feels strongly about the adoption of these technologies. According to Weiss, “Distributed Transmission provides broadcasters with many opportunities to overcome propagation obstacles, to maximize coverage and service, to achieve set top reception, and to deliver more uniform signal levels, all without requiring additional spectrum or causing new interference.”

Other new technologies are also driving the development of distributed transmission. Robust modulation techniques, also known as Enhanced VSB, are supported in the ATSC candidate standard for Distributed Transmission. The architecture of the Distributed Transmission Adaptor can be used as the foundation for implementation of Enhanced VSB, even in single transmitter systems.

Additional demonstrations of both the distributed transmission and RF watermark technologies will be held in the Axcera booth at NAB 2003 on April 7-10.

Axcera offers some of the most advanced DTV transmitter products on the market including ADE™;, the industry's first continuous linear and non-linear adaptive correction system. With UHF and VHF low power units, Innovatorª; DT series high power solid state and Visionary™ DT IOT-based transmitters, Axcera products cover DTV power levels from 50 watts to 180 kilowatts.

About Axcera
Axcera (www.axcera.com) is a premier provider of RF transmission equipment and systems for the television broadcast and broadband wireless/MMDS industries. Carrying on the tradition of offering the best RF products for over 20 years, the company has earned its reputation as a high quality manufacturer, focused on meeting customers' needs. Today Axcera provides the most complete line of television transmitter systems available from any manufacturer as well as end-to-end broadband wireless/MMDS solutions, including complete network planning, design and integration services, while never losing the focus on quality and the customer.