OPTICAL LINE TERMINAL AND OPTICAL NETWORK UNIT

• US 20130202302A1
• Filed: 03/12/2013
• Published: 08/08/2013
• Est. Priority Date: 02/24/2009
• Status: Active Grant

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: KUBO, Ryogo, Kani, Jun-ichi, Otaka, Akihiro
• Granted Patent: US 9,596,046 B2
• Time in Patent Office: Days
• US Class Current: 398/66
• CPC Class Codes: H04B 10/25 Arrangements specific to fibre transmission
• CPC Class Codes: H04J 14/0221 Power control, e.g. to keep the total optical power constant
• CPC Class Codes: H04L 12/12 Arrangements for remote connection or disconnection of substations or of equipment thereof
• CPC Class Codes: H04Q 11/0067 Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
• CPC Class Codes: H04Q 2011/0079 Operation or maintenance aspects
• CPC Class Codes: H04Q 2011/0083 Testing; Monitoring
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

An optical line terminal which includes an observing unit that observes information of any one or all of an arrival interval of frames, an instantaneous bandwidth under use of a flow, a queue length of a queue temporarily storing the frames, and a traffic type, and a stop determining unit that dynamically determines a sleep time to be a period in which a sleep state where partial functions of the ONU are stopped is maintained, on the basis of the information obtained by the observing unit. The ONU is entered into a sleep state, immediately after communication ends, after a predetermined waiting time passes from when the communication ends, or after a waiting time determined on the basis of the information passes from when the communication ends.

Claims

1. An optical line terminal in an optical network in which the optical line terminal (OLT) and an optical network unit (ONU) communicate with each other through an optical fiber transmission path, the optical line terminal including:

an observing unit that observes at least one of protocol information and priority information of frames transmitted to the ONU and frames received from the ONU;

a table where the priority information and/or the protocol information is associated with a sleep time to be a period in which a sleep state where non-used functions of the ONU are stopped is maintained; and

a table associating unit that dynamically determines the sleep time of the ONU by referring to the table, on the basis of the priority information and/or the protocol information obtained by the observing unit,

wherein a control signal to notify the ONU of a sleep state entering request and the sleep time is transmitted to the ONU, immediately after communication with the ONU ends, after a predetermined time passes from when the communication with the ONU ends, or after a time determined on the basis of the priority information and/or the protocol information passes from when the communication with the ONU ends.

2. A method of controlling a sleep state of an optical network unit in an optical network in which an optical line terminal (OLT) and the optical network unit (ONU) communicate with each other through an optical fiber transmission path, the method including:

a step that the OLT observes at least one of protocol information and priority information of frames transmitted to the ONU and frames received from the ONU;

a step that the OLT dynamically determines the sleep time of the ONU by referring to a table where the priority information and/or the protocol information is associated with a sleep time to be a period in which a sleep state where non-used functions of the ONU are stopped is maintained, on the basis of the priority information and/or the protocol information to be observed;

a step that the OLT transmits a control signal to notify the ONU of a sleep state entering request and the sleep time to the ONU, immediately after communication with the ONU ends, after a predetermined time passes from when the communication with the ONU ends, or after a time determined on the basis of the priority information and/or the protocol information passes from when the communication with the ONU ends;

a step that the ONU recognizes the sleep state entering request and the sleep time using the control signal received from the OLT; and

a step that the ONU enters into the sleep state immediately after the control signal is received, after a predetermined time passes from when the control signal is received, or after a time designated by the OLT passes from when the control signal is received, and return to a normal state after the sleep time passes.

3. An optical network system, including:

one optical line terminal (OLT) and one optical network unit (ONU), wherein the OLT performs point-to-point communication with the ONU through an optical fiber transmission path,

the OLT including;

an observing unit that observes at least one of protocol information and priority information of frames transmitted to the ONU and frames received from the ONU;

a table where the priority information and/or the protocol information is associated with a sleep time to be a period in which a sleep state where non-used functions of the ONU are stopped is maintained; and

a table associating unit that dynamically determines the sleep time of the ONU by referring to the table, on the basis of the priority information and/or the protocol information obtained by the observing unit,

wherein a control signal to notify the ONU of a sleep state entering request and the sleep time is transmitted to the ONU, immediately after communication with the ONU ends, after a predetermined time passes from when the communication with the ONU ends, or after a time determined on the basis of the priority information and/or the protocol information passes from when the communication with the ONU ends,

the ONU including;

a sleep unit that stops non-used functions to enter into a sleep state,

wherein a sleep state entering request and a sleep time to be a period in which the sleep state is maintained are recognized using a control signal received from the OLT, the optical network unit enters into the sleep state by the sleep unit, immediately after the control signal is received, after a predetermined time passes from when the control signal is received, or after a time designated by the OLT passes, and the optical network unit returns to a normal state after the sleep time passes.

4. An optical network system, including:

one optical line terminal (OLT) and a plurality of optical network units (ONU),

wherein the OLT performs point-to-multi-point communication with the ONUS through an optical fiber transmission path,

the OLT including;

an observing unit that observes at least one of protocol information and priority information of frames transmitted to the ONU and frames received from the ONU;

a table where the priority information and/or the protocol information is associated with a sleep time to be a period in which a sleep state where non-used functions of the ONU are stopped is maintained; and

a table associating unit that dynamically determines the sleep time of the ONU by referring to the table, on the basis of the priority information and/or the protocol information obtained by the observing unit,

wherein a control signal to notify the ONU of a sleep state entering request and the sleep time is transmitted to the ONU, immediately after communication with the ONU ends, after a predetermined time passes from when the communication with the ONU ends, or after a time determined on the basis of the priority information and/or the protocol information passes from when the communication with the ONU ends,

the ONU including;

a sleep unit that stops non-used functions to enter into a sleep state,

wherein a sleep state entering request and a sleep time to be a period in which the sleep state is maintained are recognized using a control signal received from the OLT, the optical network unit enters into the sleep state by the sleep unit, immediately after the control signal is received, after a predetermined time passes from when the control signal is received, or after a time designated by the OLT passes, and the optical network unit returns to a normal state after the sleep time passes.