ONU delay and jitter measurement

• US 8,289,858 B2
• Filed: 12/12/2006
• Issued: 10/16/2012
• Est. Priority Date: 12/13/2005
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Brolin, Stephen J., Vladescu, Virgil
• Primary Examiner(s): Hailu, Kibrom T
• Application Number:
  US11/637,023
• Publication Number:
  US 20070133424A1
• Time in Patent Office: 2,135 Days
• Field of Search: 370/279, 370/250, 370/252, 370/392, 398/208, 398/16
• US Class Current: 370/249
• CPC Class Codes: H04J 2203/0094 Virtual Concatenation
• CPC Class Codes: H04J 3/1694 Allocation of channels in TDM/TDMA networks, e.g. distributed multiplexers Passive Optical Networks H04Q11/0062
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 41/0213 Standardised network management protocols, e.g. simple network management protocol [SNMP]
• CPC Class Codes: H04L 41/024 using relational databases for representation of network management data, e.g. managing via structured query language [SQL]
• CPC Class Codes: H04L 41/042 comprising distributed management centres cooperatively managing the network
• CPC Class Codes: H04L 41/0806 for initial configuration or provisioning, e.g. plug-and-play
• CPC Class Codes: H04L 41/0856 by backing up or archiving configuration information
• CPC Class Codes: H04L 41/5054 Automatic deployment of services triggered by the service manager, e.g. service implementation by automatic configuration of network components
• CPC Class Codes: H04L 41/509 wherein the managed service relates to media content delivery, e.g. audio, video or TV
• CPC Class Codes: H04L 43/50 Testing arrangements
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 49/15 Interconnection of switching modules
• CPC Class Codes: H04L 49/1523 Parallel switch fabric planes
• CPC Class Codes: H04L 49/30 Peripheral units, e.g. input or output ports
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/352 Gigabit ethernet switching [GBPS]
• CPC Class Codes: H04L 49/357 Fibre channel switches
• CPC Class Codes: H04L 49/50 Overload detection or protection within a single switching element
• CPC Class Codes: H04Q 11/0062 Network aspects
• 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 11/0071 : Provisions for the electrical-optical layer interface
• CPC Class Codes: H04Q 2011/0079 : Operation or maintenance aspects
• CPC Class Codes: H04Q 2011/0083 : Testing; Monitoring
• CPC Class Codes: H04Q 2011/0084 : Quality of service aspects
• CPC Class Codes: H05K 7/20009 : using a gaseous coolant in electronic enclosures in cabinets of standardized dimensions H05K7/20536; in server cabinets H05K7/20709; in vehicle electronic casings H05K7/20845; in power control electronics H05K7/2089; in displays H05K7/20954
• CPC Class Codes: H05K 7/202 : Air circulating in closed loop within enclosure wherein heat is removed through heat-exchangers
• CPC Class Codes: Y04S 40/00 : Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them

Abstract

A system and method provide measurement of round trip delay and jitter in an optical network without adding cost to the components of the network. A method of determining round-trip delay and jitter in an optical network comprises the steps of a) transmitting a test frame over the optical network to a device on the optical network, b) receiving a looped-back test frame from the device over the optical network, and c) determining a round-trip delay measurement using the received looped-back test frame.

Claims

1. A method of determining round-trip delay and jitter in an optical network, comprising the steps of:

a) transmitting a test frame over the optical network from an Optical Line Termination unit in the optical network to a plurality of Optical Line Units, a plurality of Optical Network Units, or both, in the optical network, each test frame identified by a Gigabit Passive Optical Network (“

GPON”

) Encapsulation Method tag that is unique to each Optical Line Unit or Optical Network Unit and including a time stamp generated by the Optical Line Termination Unit using a time reference of the Optical Line Termination Unit;

b) receiving, at the Optical Line Termination Unit, a looped-back test frame from each of the plurality of Optical Line Units, the plurality of Optical Network Units, or both, over the optical network, wherein the test frame has been looped-back in data link layer (Layer

     2) hardware circuitry that is not a processor, the time references of the plurality of Optical Line Units and the plurality of Optical Network Units are not aligned to the time reference of the Optical Line Termination Unit, and the looped-back test frame was not time-stamped at the ONU; and

c) determining a round-trip delay measurement based on a difference of the time stamp generated by the Optical Line Termination unit and included in the looped-back test frame and the time the Optical Line Termination unit received the looped-back using the time reference of the Optical Line Termination Unit used to generate the time stamp.

2. The method of claim 1, further comprising the steps of:

performing a plurality of iterations of steps a)-c) to determine a plurality of round-trip delay measurements;

determining a maximum round-trip delay measurement of the plurality of determined round-trip delay measurements;

determining a minimum round-trip delay measurement of the plurality of determined round-trip delay measurements; and

determining a jitter measurement based on a difference between the maximum round-trip delay measurement and the minimum round-trip delay measurement.

3. Apparatus for determining round-trip delay and jitter in an optical network, comprising:

a) circuitry in Optical Line Termination unit in the optical network operable to transmit a test frame over the optical network to a plurality of Optical Line Units, a plurality of Optical Network Units, or both, in the optical network, each test frame identified by a Gigabit Passive Optical Network (“

GPON”

) Encapsulation Method tag that is unique to each Optical Line Unit or Optical Network Unit and including a time stamp generated by the Optical Line Termination Unit using a time reference of the Optical Line Termination Unit;

b) circuitry in the Optical Line Termination Unit operable to receive a looped-back test frame from each of the plurality of Optical Line Units, the plurality of Optical Network Units, or both, over the optical network, wherein the test frame has been looped-back in data link layer (Layer

     2) hardware circuitry that is not a processor, the time references of the plurality of Optical Line Units and the plurality of Optical Network Units are not aligned to the time reference of the Optical Line Termination Unit, and the looped-back test frame was not time-stamped at the ONU; and

c) circuitry operable to determine a round-trip delay measurement based on a difference of the time stamp generated by the Optical Line Termination unit and included in the looped-back test frame and the time the Optical Line Termination unit received the looped-back using the time reference of the Optical Line Termination Unit used to generate the time stamp.

4. The apparatus of claim 3, further comprising:

circuitry operable to repeatedly operate circuitry a)-c) to determine a plurality of round-trip delay measurements;

circuitry operable to determine a maximum round-trip delay measurement of the plurality of determined round-trip delay measurements;

circuitry operable to determine a minimum round-trip delay measurement of the plurality of determined round-trip delay measurements; and

circuitry operable to determine a jitter measurement based on a difference between the maximum round-trip delay measurement and the minimum round-trip delay measurement.

5. An Optical Network Unit operable with an Optical Line Termination unit to determine round-trip delay and jitter in an optical network, comprising:

a) circuitry operable to receive and recognize a test frame over the optical network from the Optical Line Termination unit, each test frame identified by a Gigabit Passive Optical Network (“

GPON”

) Encapsulation Method tag that is unique to each Optical Line Unit or Optical Network Unit and including a time stamp generated by the Optical Line Termination Unit using a time reference of the Optical Line Termination Unit; and

b) circuitry operable to loop-back in data link layer (Layer

     2) hardware circuitry that is not a processor the test frame to each of the plurality of Optical Line Units, Optical Network Units, or both, for determination of the round-trip delay measurement based on a difference of the time stamp generated by the Optical Line Termination unit and included in the looped-back test frame and the time the Optical Line Termination unit received the looped-back using the time reference of the Optical Line Termination Unit used to generate the time stamp, wherein

the time references of the plurality of Optical Line Units and the plurality of Optical Network Units are not aligned to the time reference of the Optical Line Termination Unit, and the looped-back test frame was not time-stamped at the ONU.

6. The Unit of claim 5, wherein the Optical Line Termination is operable to determine a jitter measurement based on a difference between a maximum round-trip delay measurement and a minimum round-trip delay measurement determined from a plurality of round-trip delay measurements.