Wavelength division multiplexed (WDM) ring passive optical network (PON) with route protection for replacement of splitter based passive optical networks

• US 6,898,206 B2
• Filed: 06/06/2001
• Issued: 05/24/2005
• Est. Priority Date: 06/06/2001
• Status: Expired due to Fees

• Current Assignee: Tellabs Bedford, Inc. (Infinera Corp.)
• Original Assignee: Advanced Fibre Access Corporation
• Inventors: Zuhdi, Muneer, Wawro, Debra D., Trick, Ulrich, Volk, Thomas, Buabbud, George H.
• Primary Examiner(s): Ho, Duc
• Assistant Examiner(s): Nguyen, Phuongchau Ba
• Application Number:
  US09/876,439
• Publication Number:
  US 20020186439A1
• Time in Patent Office: 1,448 Days
• Field of Search: 370/463, 370/466, 370/532, 370535-537, 398 58- 59, 398/20, 398/167, 398141-142, 714/22
• US Class Current: 370/463
• CPC Class Codes: H04B 10/27 Arrangements for networking
• CPC Class Codes: H04B 10/272 Star-type networks or tree-type networks
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 14/0227 Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
• CPC Class Codes: H04J 14/0246 using one wavelength per ONU
• CPC Class Codes: H04J 14/0247 Sharing one wavelength for at least a group of ONUs
• CPC Class Codes: H04J 14/025 using one wavelength per ONU, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
• CPC Class Codes: H04J 14/0252 Sharing one wavelength for at least a group of ONUs, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
• CPC Class Codes: H04J 14/0282 WDM tree architectures
• CPC Class Codes: H04J 14/0291 Shared protection at the optical multiplex section (1:1, n:m)

Abstract

A method and apparatus for low cost upgrading on demand of an optical fiber communication system without installing additional optical fiber and minimal installation of optical circuitry at destination and distribution terminals. The upgraded systems comprise an optical data loop of a plurality of destination terminals and a single intermediate terminal.

Claims

1. In an existing optical network comprising a multiplicity of destination terminals, an intermediate terminal, and a primary terminal, each of said multiplicity of destination terminals including an optical interface unit (OIU) having an OIU input optical connector and an OIU output optical connector and each OIU for extracting data on lightwaves received at said OIU input optical connector and injecting data onto lightwaves transmitted from said OIU output optical connector, each of said destination terminals having a corresponding pair of optical fibers extending to said intermediate terminal, each of said corresponding pairs of optical fibers including a first fiber and a second fiber, and each of said OIU connected by said OIU input optical connector and said OIU output optical connector to each corresponding first fiber and second fiber, and said intermediate terminal connected to said primary terminal by at least a primary pair of optical fibers, apparatus for providing optical data transmission comprising:

a first conversion circuit located in said intermediate terminal having a first conversion input optical connector and a first conversion output optical connector, said first conversion circuit for converting optical data to electrical data and electrical data to optical data, said first conversion circuit further including electrical connections;

a transmission loop comprising said multiplicity of destination terminals and said corresponding pairs of optical fibers wherein;

at each of said multiplicity of destination terminals, said first fiber of said corresponding pair of optical fibers connected to said OIU output optical connector, and said second fiber of said corresponding pair of optical fibers connected to said OIU input optical connector; and

at said intermediate terminal said first fibers of said corresponding pairs of optical fibers connected to said second fibers of other of said corresponding pairs of optical fibers, except said first optical fiber of one of said corresponding pairs of optical fibers is connected to said first conversion input optical connector and said second optical fiber of another one of said corresponding pairs of optical fibers is connected to said first conversion output optical connector; and

a second conversion circuit located in said intermediate terminal for converting optical data to electrical data and electrical data to optical data and electrically connected to said electrical connections of said first conversion circuit, said second conversion circuit also optically connected to said primary pair of optical fibers extending between said intermediate terminal and said primary terminal.

2. In an existing optical network comprising a multiplicity of destination terminals, each of said destination terminal having a corresponding pair of optical fibers, each corresponding pair of optical fibers having a first fiber and a second fiber, and each of said destination terminals connected to an intermediate terminal by its corresponding pair of optical fibers, and said intermediate terminal connected to a primary terminal by at least a pair of primary optical fibers, apparatus for providing upgraded optical data transmission comprising:

a first conversion circuit located in said intermediate terminal having a first conversion output optical connector and a first conversion input optical connector for connecting optical fibers to optically transmit and receive bidirectional data between said intermediate terminal and said multiplicity of destination terminals, said first conversion circuit for converting optical data to electrical data and electrical data to optical data, said first optical conversion circuit further including electrical connections;

a first optical interface unit (OIU) and a last OIU, said first and last OIUs located in a first destination terminal and a last destination terminal, respectively, said first and last destination terminals included in said multiplicity of destination terminals, each of said first and last OIUs;

including an input optical connector and an output optical connector, said first and last OIUs for extracting and inserting data on lightwaves traveling over optical fibers, and said lightwaves being received at said input optical connectors and transmitted from said output connectors of said first and last OIUs, wherein;

said first fiber of said corresponding pair of optical fibers of said first destination terminal is connected to said first conversion output optical connector of said first conversion circuit, and said second fiber of said corresponding pair of optical fibers of said last destination terminal connected to said first conversion input optical connector of said first conversion circuit, the second fiber of said corresponding pair of optical fibers of said first destination terminal and the first fiber of said corresponding pair of optical fibers of said last destination terminal connected so as to form a series optical loop extending between said first conversion output optical connector of said first conversion circuit and at least through said first and last destination terminals and back to said first conversion input optical connector of said first conversion circuit; and

a second conversion circuit located in said intermediate terminal for converting optical data to electrical data and electrical data to optical data, and electrically connected to said first conversion circuit, said second conversion circuit also optically connected to said pair of primary optical fibers extending between said intermediate terminal and said primary terminal.

3. The apparatus of claim 2 wherein said second fiber or said corresponding pair of optical fibers of said first destination terminal and said first fiber of said corresponding pair of optical fibers of said last destination terminal are connected directly to each other.

4. The apparatus of claim 2 wherein said optical interface unit is a broadband optical interface unit.

5. An apparatus for facilitating optical communication between a first terminal and a first remote optical interface unit (OIU) and a second remote OIU, each remote OIU having an OIU optical input and an OIU optical output, the first and second remote OIUs associated with a first pair and a second pair of optical fibers, respectively, each pair of optical fibers comprising a first fiber and a second fiber, the apparatus comprising:

an optical communication unit located within the first terminal and having an optical communication unit input and an optical communication output, wherein;

the OIU optical input of first remote OIU is connected to the optical communication output of the optical communication unit by the first fiber of the first pair of optical fibers;

the OIU optical output of the second remote OIU is connected to the optical communication input of the optical communication unit by the second fiber of the second pair of optical fibers;

the OIU optical output of first remote OIU is connected to the second fiber of the first pair of optical fibers;

the OIU optical input of second remote OIU is connected to the first fiber of the second pair of optical fibers; and

the second fiber of the first pair of optical fibers and the first fiber of the second pair of optical fibers define an optical communication loop separate from the optical communication unit;

wherein the optical communication loop is defined by the second fiber of the first pair of optical fibers and the first fiber of the second pair of optical fibers by directly connecting the second fiber of the first pair of optical fibers to first fiber of the second pair of optical fibers.

6. The apparatus of claim 5, wherein the optical communication loop is defined by the second fiber of the first pair of optical fibers and the first fiber of the second pair of optical fibers by intermediate OIUs each having an OIU optical input and an OIU optical output and each intermediate OIU having a corresponding pair of optical fibers comprising a first fiber and a second fiber.

7. The apparatus of claim 5, wherein the first and second OIUs are broadband OIUs.

8. The apparatus of claim 5, further comprising at least one optical bypass switch associated with one of the first or second remote OIUs and connected across the corresponding first or second pair of optical fibers.