Optical transmission system and method using an optical carrier drop/add transceiver

• US 6,466,342 B1
• Filed: 12/27/1999
• Issued: 10/15/2002
• Est. Priority Date: 02/18/1999
• Status: Expired due to Term

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Frigo, Nicholas J., Reichmann, Kenneth C., Iannone, Patrick P.
• Primary Examiner(s): NEGASH, KINFE MICHAEL
• Application Number:
  US09/472,338
• Time in Patent Office: 1,023 Days
• Field of Search: 359/118-119, 359/127, 359/152, 359/181
• US Class Current: 398/82
• CPC Class Codes: H04B 10/271 Combination of different networks, e.g. star and ring configuration in the same network or two ring networks interconnected
• CPC Class Codes: H04B 10/2755 Ring-type networks with a headend
• CPC Class Codes: H04J 14/0204 Broadcast and select arrangements, e.g. with an optical splitter at the input before adding or dropping
• 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 14/0241 Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths
• CPC Class Codes: H04J 14/0245 for downstream transmission, e.g. optical line terminal [OLT] to ONU
• CPC Class Codes: H04J 14/0249 for upstream transmission, e.g. ONU-to-OLT or ONU-to-ONU
• CPC Class Codes: H04J 14/0283 WDM ring architectures

Abstract

An optical carrier drop/add transmission system and method using a same optical carrier to both drop traffic from an optical network and to add traffic to the optical network. An optical carrier signal is received by a transceiver and is subsequently split into a first and second optical signal. The first optical signal can be converted into an electrical signal for processing by the subscriber (i.e., data out). The electrical signal corresponding to the first optical signal is additionally inverted by the transceiver. The inverted electrical signal is subsequently modulated with the second optical signal in order to create a nominally flat signal (“optical chalkboard”). The subscriber'"'"'s data is then modulated onto the flat signal and sent across the optical network. As a consequence, the network subscriber controls the format and protocols of the data traffic on the optical network, while the optical network service provider controls the optical carrier wavelengths, which are of primary concern to maintain organization and efficiency on the optical network.

Claims

1. A method for adding and dropping data from an optical network using a single optical carrier, comprising:

accepting an optical signal from the optical network;

splitting the optical signal into a first optical signal and a second optical signal;

removing data from the second optical signal based on the first optical signal to create a third optical signal; and

writing data onto the third optical signal.

2. The method according to claim 1, wherein removing data from the second optical signal to create the third optical signal, further comprises:

converting the first optical signal into an electrical signal;

inverting the electrical signal;

converting the electrical signal into a suppressing optical signal; and

combining the suppressing optical signal with the second optical signal to remove the data from the second optical signal.

3. The method according to claim 1, further comprising:

transmitting the third optical data signal on the optical network.

4. The method according to claim 1, wherein removing data from the second optical signal to create the third optical signal, further comprising:

inverting the first optical signal to form a suppressing optical signal; and

combining the suppressing optical signal with the second optical signal to remove the data from the second optical signal.

5. The method according to claim 1, wherein the optical network is an optical ring network.

6. A method for adding and dropping data from an optical network using an optical carrier, comprising:

receiving an optical carrier containing first data;

detecting the first data on the optical carrier; and

adjusting the optical carrier to include second data.

7. The method according to claim 6, wherein receiving the optical carrier further includes, splitting the optical carrier into a first portion and a second portion.

8. The method according to claim 7, wherein the first data is detected on the first portion of the optical carrier signal.

9. The method according to claim 8, wherein the second portion of the optical carrier signal is adjusted to remove the first data.

10. The method according to claim 6, further comprising:

removing the first data from the optical carrier using at least one of an optical limiter and an injection locked laser.

11. The method according to claim 9, wherein the second portion of the optical carrier is further adjusted to include second data.

12. An apparatus that adds and drops data from an optical network using a single optical carrier, comprising:

a receiver connected with the optical network that receives optical signals from the optical network;

an optical splitter connected with the receiver that splits the optical signal into a first optical signal and a second optical signal;

a suppressing modulator that removes data from the second optical signal based on the first optical signal to create a third optical signal; and

a writing modulator that writes data onto the third optical signal.

13. The apparatus according to claim 12, wherein the suppressing modulator removes data from the second optical signal to create the third optical signal by converting the first optical signal into an electrical signal, inverting the electrical signal, converting the electrical signal into a suppressing optical signal, and combining the suppressing optical signal with the second optical signal to remove the data from the second optical signal and create the third optical signal.

14. The apparatus according to claim 12, wherein the suppressing modulator removes data from the second optical signal to create the third optical signal by inverting the first optical signal to form a suppressing optical signal and combining the suppressing optical signal with the second optical signal to remove the data from the second optical signal.

15. The apparatus according to claim 12, wherein the optical network is an optical ring network.