Delivery method and delivery system of contents information, and central station thereof

• US 7,616,892 B2
• Filed: 05/31/2005
• Issued: 11/10/2009
• Est. Priority Date: 03/04/2003
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Nakazato, Hiroaki, Suzuki, Yasuo
• Primary Examiner(s): WANG, QUAN ZHEN
• Application Number:
  US11/141,708
• Publication Number:
  US 20050259541A1
• Time in Patent Office: 1,624 Days
• Field of Search: 398 66- 72, 398 70- 71, 398/79, 398/48
• US Class Current: 398/72
• CPC Class Codes: H04J 14/0226 Fixed carrier allocation, e.g. according to service
• CPC Class Codes: H04J 14/0232 for downstream transmission
• CPC Class Codes: H04J 14/0246 using one wavelength per ONU
• 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 14/0282 WDM tree architectures
• CPC Class Codes: H04N 7/22 Adaptations for optical transmission

Abstract

A contents information delivery method for delivering a desired contents information by transmitting an optical signal from a central station to each of a plurality of user stations via a transmission line includes: a first step (S1) of outputting an optical signal containing the contents information as an optical signal having mutually different wavelengths each assigned for the each user station in advance, in the central station; a second step (S2) of transmitting an optical signal having a plurality of wavelengths outputted via the transmission line in the first step; and a third step (S3), in which each user station receives the optical signal having the wavelength assigned from among the transmitted optical signals, whereby, this simple configuration does not limit the transmission rate, the coding format, or the like in an optical access system, i.e., making it possible to cope with a super-large capacity.

Claims

1. A contents information delivery method of delivering a desired contents information to at least one of a plurality of user stations via a central station, the contents information delivery method comprising the steps of:

in the central station,

receiving a plurality of contents-included optical signals each having a first wavelength different from each other, each said contents-included optical signal being transmitted from one of a plurality of contents sources,

generating a set of the received plurality of contents-included optical signals for each of the user stations,

selecting one of the plurality of contents-included optical signals from the set for each of at least one of the plurality of user stations, respectively;

performing interruption/non-interruption control of the contents-included optical signal selected for each of at least one of the plurality of user stations;

converting the first wavelength of the contents-included optical signal to be passed through thereof by the interruption/non-interruption control into a second wavelength assigned for each of the user stations, respectively,

wavelength multiplexing the wavelength-converted contents-included optical signals, and

outputting and transmitting the wavelength multiplexed optical signal via a transmission line; and

in each of the user stations,

receiving an optical signal having the second wavelength assigned to one of the user stations from among wavelengths of said wavelength multiplexed optical signal.

2. The contents information delivery method according to claim 1, further comprising a step of wavelength-separating said wavelength multiplexed optical signal in local equipment on said transmission line.

3. The contents information delivery method according to claim 2, wherein

said wavelength multiplexed optical signal is transmitted via a first optical fiber constituting the transmission line, and wherein

in said wavelength-separating step, the local equipment wavelength-separates the multiplexed optical signal from the first optical fiber, and also outputs said wavelength-separated optical signal to a second optical fiber leading to a user station to which the wavelength of the wavelength-separated optical signal is assigned.

4. The contents information delivery method according to claim 3, further comprising:

a control information outputting step in which each user station outputs control information for delivering said contents information as an optical control signal having a wavelength, which differs for each user station and also differs from the wavelength assigned for the contents information delivery to each user station, via said second optical fiber to the local equipment; and

a control information multiplexing step of wavelength-multiplexing the control signal inputted from each user station via the second optical fiber in the local equipment, and of transmitting the wavelength multiplexed control signal to the central station via a third optical fiber different from said first optical fiber and second optical fiber, wherein

said central station outputs the wavelength multiplexed optical signal containing said contents information in wavelengths assigned to each user station, based on the wavelength multiplexed control signal from the local equipment.

5. The contents information delivery method according to claim 3, further comprising:

a control information outputting step in which each user station outputs control information for delivering of said contents information as an optical control signal having a wavelength, which differs for each user station and also differs from the wavelength assigned for the contents information delivery to each user station, via the second optical fiber to the local equipment; and

a control information multiplexing step of wavelength-multiplexing the control signal inputted from each user station via the second optical fiber in the local equipment, and of transmitting the wavelength multiplexed control signal to the central station via the first optical fiber, wherein

said central station outputs the wavelength multiplexed optical signal containing said contents information in wavelengths assigned to each user station, based on the wavelength multiplexed control signal from the local equipment.

6. The contents information delivery method according to claim 2, wherein in the wavelength-separating step, said wavelength multiplexed optical signal is wavelength-separated in a passive element in the local equipment.

7. The contents information delivery method according to claim 6, wherein in the wavelength-separating step, said wavelength multiplexed optical signal is wavelength-separated in an array waveguide grid as the passive element in said local equipment.

8. The contents information delivery method according to claim 1, wherein in the wavelength conversion step, a semiconductor optical amplifier converts the wavelength of the contents-included optical signal inputted therein into a wavelength of a light from a light source using a cross gain modulation characteristic of the semiconductor optical amplifier itself, which the wavelength of the light is the wavelength assigned for the specific user station.

9. The contents information delivery method according to claim 1, further comprising a control information transmitting step of transmitting, from each user station to the central station, control information for delivering said contents information to said each user station.

10. The contents information delivery method according to claim 9, wherein in the control information transmitting step, each user station transmits the control information to the central station via other existing lines.

11. The contents information delivery method according to claim 9, wherein the control information is contents-selection information that the user station selects to receive.

12. The contents information delivery method according to claim 1, wherein the central station performs administration of subscriber information in each of the plurality of user stations upon receipt of control information from corresponding user station, and performs interruption/non-interruption control of the contents-included optical signal selected for each of at least one of the plurality of user stations based on the administration.

13. A contents information delivery system for delivering contents information from a plurality of contents sources to at least one of a plurality of user stations via a central station,

wherein said central station comprises:

a receiving section that receives a plurality of contents-included optical signals each having a first wavelength different from each other, each said contents-included optical signal being transmitted from one of a plurality of contents sources,

a generating section that generates a set of the received plurality of contents-included optical signals for each of the user stations,

a selecting section that selects one of the plurality of contents-included optical signals from the set for each of at least one of the plurality of user stations, respectively, and performs interruption/non-interruption control of the contents-included optical signal selected for each of at least one of the plurality of user stations;

a converting section that converts the first wavelength of the contents-included optical signal to be passed through thereof by the interruption/non-interruption control into a second wavelength assigned for each of the user stations, respectively,

a multiplexing section that wavelength multiplexes the wavelength-converted contents-included optical signals, and

an optical signal outputting section that outputs and transmits the wavelength-multiplexed optical signal via a transmission line;

wherein the contents information delivery system comprises local equipment having a first wavelength separating section that wavelength-separates the wavelength-multiplexed optical signal on the transmission line; and

wherein each user station comprises a receiving section that receives an optical signal having the second wavelength assigned to one of the user stations from among wavelengths of the wavelength-multiplexed optical signal, which is wavelength-separated in the first wavelength separating section in the local equipment.

14. The contents information delivery system according to claim 13, wherein the local equipment on the transmission line is arranged at the user station side remotely from the central station.

15. The contents information delivery system according to claim 13, wherein said central station performs administration of subscriber information in each of the plurality of user stations upon receipt of control information from corresponding user station, and performs interruption/non-interruption control of the contents-included optical signal selected for each of at least one of the plurality of user stations based on the administration.

16. A central station in a contents information delivery system for delivering contents information from a plurality of contents sources to at least one of a plurality of user stations via the central station, the central station comprising:

a receiving section that receives a plurality of contents-included optical signals each having a first wavelength different from each other, each said contents-included optical signal being transmitted from one of a plurality of contents sources;

a generating section that generates a set of the received plurality of contents-included optical signals for each of the user stations;

a selecting section that selects one of the plurality of contents-included optical signals from the set for each of at least one of the plurality of user stations, respectively, and performs interruption/non-interruption control of the contents-included optical signal selected for each of at least one of the plurality of user stations;

a converting section that converts the first wavelength of the contents-included optical signal to be passed through thereof by the interruption/non-interruption control into a second wavelength assigned for each of the user stations, respectively;

a multiplexing section that wavelength multiplexes the wavelength-converted contents-included optical signals; and

an optical signal outputting section that outputs and transmits the wavelength-multiplexed optical signal via a transmission line, wherein

each user station comprises a receiving section that receives an optical signal having the second wavelength assigned to one of the user stations from among wavelengths of the wavelength-multiplexed optical signal on the transmission line.

17. The central station according to claim 16, wherein said central station performs administration of subscriber information in each of the plurality of user stations upon receipt of control information from corresponding user station, and performs interruption/non-interruption control of the contents-included optical signal selected for each of at least one of the plurality of user stations based on the administration.