Patent ID: 7610608

Claim:
A digital broadcast system, comprising: a digital broadcast output unit which transmits a plurality of digital broadcast channels that has been multiplexed and encrypted in an Ethernet frame form, via an optical line terminal (OLT) on an Ethernet passive optical network (E-PON); and a plurality of optical network units (ONUs) which provide one of the digital broadcast channels to a user in response to a user channel selection, by using a part of bandwidth assigned for an existing line, wherein each ONU comprises: a digital broadcast processor which receives an MPEG stream containing all of the digital broadcast channels transmitted from the digital broadcast output unit over the E-PON, demultiplexes a plurality of Ethernet frames corresponding to all of the of the digital broadcast channels, and transmits, in response to the user's channel selection, one of the demultiplexed Ethernet frames that is corresponding to the digital broadcast channel selected by the user, to the user's optical network terminal (ONT); and an Ethernet switch to transmit the Ethernet frame for the digital broadcast channel to an ONT provided at a location of the user, wherein the digital broadcast processor further comprises: an Ethernet frame generator, in response to the user channel selection, to encapsulate the MPEG stream corresponding to the digital broadcast channel selected by the user in the Ethernet frame for the digital broadcast channel and to include the user's address as a destination address.