US 7,321,730 B2 | ||
Method and apparatus for the transmission fault detection in an access network | ||
Kent Felske, Kanata (Canada); Richard Brand, Palo Alto, Calif. (US); and Eric Bernier, Nepean (Canada) | ||
Assigned to Nortel Networks Limited, St. Laurent (Canada) | ||
Filed on Jun. 23, 2003, as Appl. No. 10/600,713. | ||
Claims priority of provisional application 60/445837, filed on Feb. 06, 2003. | ||
Prior Publication US 2004/0156635 A1, Aug. 12, 2004 | ||
Int. Cl. H04J 14/00 (2006.01); H04B 10/08 (2006.01); H04B 10/14 (2006.01) |
U.S. Cl. 398—71 [398/32; 398/58; 398/10; 398/100; 398/99; 398/76; 398/66; 398/198] | 5 Claims |
1. A transmitter for an optical network unit (ONU) for transmitting data over a return data channel of a passive optical network
in accordance with a predefined time-sharing protocol, the transmitter comprising:
a laser driver for driving a laser of the transmitter to generate an optical carrier;
a modulation sub-system for modulating data onto the optical carrier generated by the laser; and
a secondary modulation sub-system for impressing an ONU identifier onto the optical carrier, the ONU identifier serving to
identify the ONU to a network monitor that monitors the return data channel, the secondary modulation sub-system comprising
a tone source for supplying a tone that serves as the ONU identifier to a tone modulator to modulate the ONU identifier onto
the optical carrier; and
a switch for selectively switching the tone to the tone modulator so that the tone modulator does not impress the ONU identifier
onto the optical carrier during a timeslot allocated to the ONU.
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