Press Release

- SD Digital Ad Insertion Added to Unique Feature Set of Powerful,

                       Award-Winning Solution -

COLOGNE, Germany--(BUSINESS WIRE)--May 27, 2008--Harmonic Inc. (NASDAQ:HLIT) today announced further enhancements to the highly advanced feature set of its IP-enabled ProStream(TM) 1000 stream processing platform, with the addition of support for MPEG-2 standard definition (SD) digital program insertion (DPI). Harmonic's ProStream(TM) 1000 with new DPI technology is easily incorporated as part of any digital turn-around (DTA) architecture and offers operators around the world a cost-effective and time-saving solution for integrating national, targeted and local advertisement insertion capabilities into their video services.

The ProStream 1000 with DPI technology supports standard digital ad insertion protocols (SCTE 30 and SCTE 35) and is designed to interoperate with third-party systems. Combined with Harmonic's IP-enabled CLEARcut(TM) offline content preparation solution and StreamLiner(R) video servers, the ProStream 1000 with DPI provides users a complete, one-stop solution for seamless, real-time splicing of MPEG-2 SD video streams. DPI technology can be easily integrated into currently installed ProStream 1000 systems, and is available via license upgrade.

"As operators around the world continue to invest in next-generation digital television and on-demand service offerings, tools that enable them to maximize the revenue-generating capacity of their video delivery networks are critical," said Yaniv Ben-Shushan, Stream Processing Product Manager for Harmonic Inc. "By integrating digital splicing capability into Harmonic's powerful and globally deployed ProStream 1000 platform, Harmonic is reducing the operational complexity and capital expenditures required to support local program and ad insertion."

Harmonic was the first in the industry to offer a multi-channel MPEG-4 AVC digital splicing solution and now is adding support for MPEG-2 to its portfolio. Harmonic's IP-enabled, single-rack unit ProStream 1000 solution delivers "headend-in-a-box" capability, supporting MPEG re-multiplexing, scrambling, descrambling, re-encoding, digital ad insertion, single frequency network (SFN) transmission over IP, distributed statistical multiplexing over IP, and forward error correction. Harmonic's NMX Digital Service Manager(TM) provides centralized management and control of the entire IP-enabled network, further simplifying network operations.

Harmonic is featuring the ProStream 1000 with DPI splicing technology as part of its comprehensive range of stream processing solutions on display in its stand #B54 at the ANGA Cable exhibition in Cologne, Germany, May 27-29.

About Harmonic Inc.

Harmonic Inc. is a leading provider of versatile and high performance video solutions that enable service providers to efficiently deliver the next generation of broadcast and on-demand services including high definition, video-on-demand, network personal video recording and time-shifted TV. Cable, satellite, broadcast and telecom service providers can increase revenues and lower operational expenditures by using Harmonic's digital video, broadband optical access and software solutions to offer consumers the compelling and personalized viewing experience that is driving the business models of the future.

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.

This press release contains forward-looking statements within the meaning of Section 27(A) of the Securities Act of 1933 and Section 21(E) of the Securities Exchange Act of 1934, including statements about the features and anticipated benefits of the enhanced ProStream 1000 stream processing platform.

Our expectations and beliefs regarding these matters and the benefits expected from the ProStream 1000 may not materialize, and actual results could differ materially from those projected. The forward-looking statements contained in this press release are also subject to other risks and uncertainties, including those more fully described in Harmonic's filings with the Securities and Exchange Commission including its recent Reports filed on Form 10-K and Form 10-Q. Harmonic does not undertake to update any forward-looking statements.

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

    CONTACT: Harmonic
             Sarah Lum, +1-408-543-2392 (Media Relations)
             sarah.lum@harmonicinc.com
             or
             StreetConnect
             Michael Newman, +1-408-542-2760
             (Investor Relations for Harmonic)
             hlit@stct.com

    SOURCE: Harmonic Inc.