1 Exhibit 21.1 HARMONIC LIGHTWAVES, INC. AND SUBSIDIARIES SUBSIDIARIES OF THE REGISTRANT The following table shows certain information with respect to the active significant subsidiaries of the Company as of December 31, 1999. STATE OR OTHER PERCENT OF VOTING JURISDICTION OF SECURITIES OWNED NAME INCORPORATION BY HARMONIC - ---- ------------- ----------- Harmonic Lightwaves (Israel), Ltd. Israel 100% Harmonic Lightwaves (UK), Ltd. United Kingdom 100% New Media Communication, Ltd. Israel 100%