US 7,542,674 B1
Optical link performance monitoring
Gianpaolo Barozzi, Milan (Italy); Mauro Macchi, Gorla Maggiore (Italy); and Andrea Marchio, Milan (Italy)
Assigned to Cisco Technology, Inc., San Jose, Calif. (US)
Filed on May 24, 2001, as Appl. No. 9/865,295.
Int. Cl. H04B 10/08 (2006.01)
U.S. Cl. 398—33  [398/16; 398/20] 4 Claims
OG exemplary drawing
 
1. An apparatus for monitoring performance of an optical communication link at an intermediate location along said link, said apparatus comprising:
a coupler that taps a portion of an optical data signal traveling along said link;
an optical amplifier that boosts said portion of said optical data signal;
an optical receiver that recovers data based on said portion of said optical data signal;
a tunable filter that isolates a particular wavelength component of said portion of said optical data signal for input to said optical receiver;
an error correction decoding circuit that identifies a number of detected errors in receipt of said data; and
a link verification stage that generates an indication of link operation based on errors identified by said error correction decoding circuit, wherein said link verification stage tunes said tunable filter to test a selected wavelength component.