Press Release

    AMSTERDAM, Netherlands--(BUSINESS WIRE)--Sept. 10, 2004--

           Harmonic's Expertise and Technical Excellence to
          Further Industry Organization's Efforts to Advance
                  High Definition Services in France

Harmonic Inc. (Nasdaq:HLIT) -- a leading provider of standard definition (SD) and high definition (HD) video compression solutions to broadcasters in France and around the world -- today announced its formal acceptance to the HD Forum, an industry organization in France driving the technical and market adoption and advancement of HDTV. Bringing more than a decade of video compression technology expertise and innovation as well as a deep knowledge and understanding of the digital television business drivers and models, Harmonic will help the Forum chart an effective course to the HD future.

The association, with a membership encompassing manufacturers, publishers, broadcasters, producers and distributors throughout the audiovisual sector, has the support of the French Government. The HD Forum's mission includes:

    --  Informing the market about the worldwide progress and
        development of HD and promoting it to the authorities and to a
        broader public;

    --  Encouraging the establishment of complete HD production and
        distribution chains across all types of media including
        terrestrial, satellite, cable and ADSL;

    --  Raising any technical questions on the choice of standards for
        HD.

"High definition with its unparalleled video and audio quality is a significant step in the evolution of television," said Dr. Yaron Simler, President of Harmonic's Convergent Systems Division. "Harmonic is a long-time participant in the definition, evolution and promotion of industry standards that foster greater interoperability, innovation and value for the broadcast and broadband markets. Our expertise and experience with MPEG-2 and advanced compression technologies, such as MPEG-4 AVC and SMPTE VC-1, will help the HD Forum define a more expedient and consistent path to this critical new television format."

Harmonic is the HDTV technology partner of choice to leading digital terrestrial, satellite, cable and telecom operators who are offering or planning broadcast and on-demand services in SD and HD formats. Through these initiatives, Harmonic has developed invaluable insights into technical and commercial considerations around HD services. This in turn has been factored into a variety of related products and services, which are further enhancing the attractiveness of the HDTV business case.

About Harmonic Inc.

Harmonic Inc. is a leading provider of digital video, broadband optical networking and IP delivery systems to cable, satellite, telecom and broadcast network operators. Harmonic's open standards-based solutions for the headend through the last mile enable customers to develop new revenue sources and a competitive advantage by offering powerful interactive video, voice and data services such as video-on-demand, high definition digital television, telephony and Internet access.

Harmonic (Nasdaq:HLIT) is headquartered in Sunnyvale, California with R&D, sales and system integration centers worldwide. The Company's customers, including many of the world's largest communications providers, deliver services in virtually every country. Visit www.harmonicinc.com for more information.

EDITOR'S NOTE -- Product and company names used herein are trademarks or registered trademarks of their respective owners.

    CONTACT: AxiCom (for Harmonic)
             Stephen Orr, 408-543-2360 (Media Relations)
             +44.(0)20.8392.4056
             stephen.orr@axicom.com
                 or
             StreetConnect (for Harmonic)
             Michael Newman, 408-542-2760 (Investor Relations)
             mnewman@stct.com

    SOURCE: Harmonic Inc.