Optical crossconnect apparatus and optical transmission system

• US 6,813,445 B2
• Filed: 01/31/2002
• Issued: 11/02/2004
• Est. Priority Date: 02/24/1997
• Status: Expired due to Fees

• Current Assignee: Hitachi Advanced Systems Corp. (Hitachi, Ltd.), Hitachi, Ltd.
• Original Assignee: Hitachi Advanced Systems Corp. (Hitachi, Ltd.), Hitachi, Ltd.
• Inventors: Hanatani, Shoichi, Sano, Hirohisa, Hayashi, Yukio, Fukashiro, Yasuyuki, Takatori, Masahiro, Kanetake, Tatsuo, Kitajima, Shigeki
• Primary Examiner(s): Negash, Kinfe-Michael
• Application Number:
  US10/059,337
• Publication Number:
  US 20020093712A1
• Time in Patent Office: 1,006 Days
• Field of Search: 359/110, 359/117, 359/128, 359/139, 359/177, 398/45, 398/50, 398/56, 398/5
• US Class Current: 398/56
• CPC Class Codes: H04B 10/032 using working and protection systems H04J14/0287 takes precedence
• CPC Class Codes: H04Q 11/0001 using optical switching
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 11/0062 Network aspects
• CPC Class Codes: H04Q 2011/0024 using space switching
• CPC Class Codes: H04Q 2011/0043 Fault tolerance
• CPC Class Codes: H04Q 2011/0058 Crossbar; Matrix
• CPC Class Codes: H04Q 2011/0081 Fault tolerance; Redundancy; Recovery; Reconfigurability

Abstract

An optical crossconnect apparatus which includes one terminal connected to a transmission path from one optical transmission terminal station and another terminal connected to a transmission path from another optical transmission terminal station, a first optical signal switch having “M1” ports and “N1” ports, through which the optical signal can pass, a second optical signal switch having “M2” ports and “N2” ports, through which the optical signal can pass, and “L” optical signal repeaters, one end connected to the “N1” ports of the first optical signal switch, and the other end connected to the “N2” ports of the second optical switch. The “N1” and the “N2” ports are equal to “L” optical signal repeaters. The “M1” ports of the first optical signal switch connected to the one terminal, and the “M2” ports of the second optical signal switch connected to the other terminal are larger than, or equal to 2.

Claims

1. An optical crossconnect apparatus having a first terminal connected to a transmission path from a first optical transmission terminal station and a second terminal connected to a transmission path from a second optical transmission terminal station, and capable of switching said transmission paths when an optical signal is transmitted from said first optical transmission terminal station to said second optical transmission terminal station and from said second optical transmission terminal to said first optical transmission terminal station, comprising:

an optical signal switching means having optical signal repeaters;

a first optical signal monitoring means, connected between said first terminal and a first port of said optical signal switching means, for monitoring a transmission condition of the optical signal input to said optical switching means; and

a second optical signal monitoring means, connected between said second terminal and a second port of said optical signal switching means, for monitoring a transmission condition of the optical signal output from said optical switching means.

2. An optical crossconnect apparatus as claimed in claim 1, further comprising:

a control unit, connected to said first optical signal monitoring means and said second optical signal monitoring means, for comparing the transmission condition of the optical signal input to said optical switching means monitored by said first optical signal monitoring means and the transmission condition of the optical signal output from said optical switching means monitored by said second optical signal monitoring means, thereby performing diagnosis for failure in the apparatus.

3. An optical crossconnect apparatus for switching optical signals by using an optical switch unit, said optical crossconnect apparatus comprising:

a first optical signal monitoring unit, provided on an input side of said optical switch unit in a first direction of transmitting an optical signal, for monitoring a transmission condition of the optical signal input to said optical switch unit; and

a second optical signal monitoring unit, provided on an output side of said optical switch unit in a second direction of transmitting the optical signal, for monitoring a transmission condition of the optical signal output from said optical switch unit,

wherein said first and second optical signal monitoring units monitor the transmission condition of the optical signal which passes through said optical switch unit.

4. An optical crossconnect apparatus according to claim 3, further comprising:

a control unit, connected to said first optical signal monitoring unit and second optical signal monitoring unit, for comparing transmission condition of a preceding optical signal monitored by said first optical signal monitoring unit with the transmission condition of a succeeding optical signal monitored by said second optical signal monitoring unit to determine whether a failure has occurred in said optical crossconnect apparatus.

5. An optical crossconnect apparatus for switching optical signals by using an optical switch unit, said optical crossconnect apparatus comprising:

a first optical signal monitoring unit, which includes an optical coupler and a photedetector and provided on an input side of said optical switch unit in a first direction of transmitting an optical signal, for monitoring a transmission condition of the optical signal; and

a second optical signal monitoring unit, which includes an optical coupler and a photodetector and provided on an output side of said optical switch unit in a second direction of transmitting the optical signal, for monitoring a transmission condition of the optical signal,

wherein said first and second optical signal monitoring units monitor the transmission condition of the optical signal which passes through said optical switch unit.

6. An optical crossconnect apparatus according to claim 5, further comprising:

a control unit, which is connected to said first optical signal monitoring unit and second optical signal monitoring unit, for comparing the transmission condition of a preceding optical signal which passed through said optical switch unit with the transmission condition of a succeeding optical signal which passed through said optical switch unit to determine whether a failure has occurred in said optical crossconnect apparatus.