WO2012167572A1 - 多框集群的光网络交换节点、光突发同步方法及线路框 - Google Patents

多框集群的光网络交换节点、光突发同步方法及线路框 Download PDF

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Publication number
WO2012167572A1
WO2012167572A1 PCT/CN2011/082939 CN2011082939W WO2012167572A1 WO 2012167572 A1 WO2012167572 A1 WO 2012167572A1 CN 2011082939 W CN2011082939 W CN 2011082939W WO 2012167572 A1 WO2012167572 A1 WO 2012167572A1
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Prior art keywords
optical
ftl
switching unit
receiving
frame
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PCT/CN2011/082939
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English (en)
French (fr)
Inventor
钟其文
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华为技术有限公司
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Priority to PCT/CN2011/082939 priority Critical patent/WO2012167572A1/zh
Priority to EP11867488.6A priority patent/EP2779484B1/en
Priority to CN201180002610.XA priority patent/CN102726058B/zh
Publication of WO2012167572A1 publication Critical patent/WO2012167572A1/zh
Priority to US14/285,164 priority patent/US9215007B2/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
    • H04B10/077—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
    • H04B10/0773—Network aspects, e.g. central monitoring of transmission parameters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0005—Switch and router aspects
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/073—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an out-of-service signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
    • H04B10/077—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
    • H04B10/077—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
    • H04B10/0775—Performance monitoring and measurement of transmission parameters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L49/00—Packet switching elements
    • H04L49/15—Interconnection of switching modules
    • H04L49/1515—Non-blocking multistage, e.g. Clos
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L7/00—Arrangements for synchronising receiver with transmitter
    • H04L7/0075—Arrangements for synchronising receiver with transmitter with photonic or optical means
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L7/00—Arrangements for synchronising receiver with transmitter
    • H04L7/04—Speed or phase control by synchronisation signals
    • H04L7/10—Arrangements for initial synchronisation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0062—Network aspects
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0062—Network aspects
    • H04Q11/0066—Provisions for optical burst or packet networks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/54—Store-and-forward switching systems 
    • H04L12/56—Packet switching systems
    • H04L12/5601—Transfer mode dependent, e.g. ATM
    • H04L2012/5672—Multiplexing, e.g. coding, scrambling
    • H04L2012/5674—Synchronisation, timing recovery or alignment
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0005—Switch and router aspects
    • H04Q2011/0007—Construction
    • H04Q2011/0018—Construction using tunable transmitters or receivers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0005—Switch and router aspects
    • H04Q2011/0007—Construction
    • H04Q2011/0024—Construction using space switching
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0005—Switch and router aspects
    • H04Q2011/0007—Construction
    • H04Q2011/0032—Construction using static wavelength routers (e.g. arrayed waveguide grating router [AWGR] )
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0005—Switch and router aspects
    • H04Q2011/0007—Construction
    • H04Q2011/0033—Construction using time division switching
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0005—Switch and router aspects
    • H04Q2011/0007—Construction
    • H04Q2011/0035—Construction using miscellaneous components, e.g. circulator, polarisation, acousto/thermo optical
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0005—Switch and router aspects
    • H04Q2011/0037—Operation
    • H04Q2011/0045—Synchronisation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0005—Switch and router aspects
    • H04Q2011/0052—Interconnection of switches
    • H04Q2011/0056—Clos
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0062—Network aspects
    • H04Q2011/0079—Operation or maintenance aspects
    • H04Q2011/0083—Testing; Monitoring
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0062—Network aspects
    • H04Q2011/0088—Signalling aspects

Definitions

  • the present invention relates to a network communication technology, and in particular, to an optical network switching node, an optical burst synchronization method, and a circuit frame of a multi-frame cluster. Background technique
  • IP Internet Protocol Television
  • P2P Point-to-Point
  • IP Internet Protocol
  • IP Internet Protocol
  • business continues to develop rapidly, making IP network traffic grow sharply, and Internet bandwidth demand is exploding.
  • IP network traffic has doubled every 12 months, and the capacity of routers has doubled every 18 months.
  • the development of Internet traffic far exceeds the speed of equipment such as routers.
  • the currently available routers and core routers in the cluster have exceeded the lTbps and lOOTbps levels respectively.
  • routers and cluster nodes Although there is room for improvement, the development of routers and cluster nodes is limited by the maturity of optical devices at high-rate ports, and due to routers. The power consumption, heat dissipation, and load-bearing capacity of the single-node and cluster nodes make the routers and cluster nodes unable to meet the growth of Internet traffic.
  • the supporting network and nodes corresponding to the IP service bearer network and nodes are the transport network and transport network nodes in parallel development.
  • the transport network and nodes not only shoulder the interconnection and transmission tasks between the router nodes, but also shoulder the dedicated line services.
  • All-optical switching is mainly achieved through the use of passive optical components for switching, with distinct low-power characteristics.
  • the industry and the research community have proposed optical packet switching/optical burst switching for carrier and network technologies for IP and IP-like services. Packet Switching/Optical Burst Switching; abbreviated as: OPS/OBS), which seeks to directly process, exchange, and buffer optical signals.
  • OPS/OBS Packet Switching/Optical Burst Switching
  • OPS/OBS concept technology is also not suitable for transmission application scenarios where reliability is relatively high in terms of data loss and reliability.
  • SDH Synchronous Digital Hierarchy
  • SONET Synchronous Optical Network
  • OTN emerging Optical Transport Network
  • Emerging OTN is the mainstream technology in the current transport network and will gradually replace the traditional SDH/SONET.
  • the emerging OTN core transport nodes are also facing the problem of capacity requirements. And compared with router nodes, the emerging capacity of emerging OTN core transport nodes far exceeds the router nodes. In general, the capacity requirements for OTN core transport nodes are several to tens of times that of core router nodes.
  • machine rejection of the overall power consumption means a corresponding level of heat dissipation requirements.
  • the heat density and power consumption density allowed in the equipment room are limited.
  • the machine rejection itself also has a limit on the allowable heat generation density and power consumption density.
  • the maximum power consumption of the machine rejection design has reached 10kw, and the average capacity of the computer room at that time was designed to be rejected by l.lkw per machine.
  • the average power consumption of the actual operation is about 1.7kw; 90% of the room capacity is designed at 3kw.
  • Each machine refuses, the actual running average power consumption is about 2kw; the highest design is 6kw per machine rejection, and the highest power consumption rejection at that time has reached 12kw.
  • the standard telecom equipment of 2200mm ( H ) x 600mm ( W ) x 600mm ( D ) is rejected by the machine.
  • the power consumption of the machine can reach 20 ⁇ 24kw, which is much higher than the current standard machine room.
  • 4 ⁇ 6kw per machine rejects the critical limit heat dissipation capacity, which is equivalent to 4 ⁇ 5 standard machine rejection power and cooling budget of the machine room.
  • the signal attenuation limited by the high-speed electric backplane is large, and the single device can only have a transmission distance of 75cm ⁇ 100cm.
  • multi-chassis cascading can only use optical or electrical interconnection and all-electrical switching.
  • the power consumption of all-electrical switching is large, which limits the multi-device cascading capability.
  • all-optical switching can be used instead of all-electrical switching, but for all-optical switching, optical burst synchronization is the key to achieving all-optical switching.
  • the invention provides an optical network switching node, an optical burst synchronization method and a line frame of a multi-frame cluster, which are used to solve the problem of optical burst synchronization, to realize a multi-frame cluster system based on OTN technology, increase system capacity, and meet increasingly The increased bandwidth requirement further solves the problem that the prior art electrical switching node achieves multi-chassis cluster limitation due to large power consumption.
  • An aspect of the present invention provides an optical burst synchronization method, including:
  • each OR of the line frame connected to the same all-optical switching unit is in accordance with an optical path difference of an output port to which the FTL in the reference frame is located, and receiving the optical burst test signal a time slot and a transmission slot number carried in the optical burst test signal, obtaining a time phase difference from an output port where the FTL in the reference frame is located, and adjusting a receiving port where the OR is located according to the time difference phase
  • Another aspect of the present invention provides an optical burst synchronization method, including:
  • An output port of the wavelength tunable transmitting laser FTL in each of the line frames connected to the same all-optical switching unit is respectively sent to a receiving port of the optical receiving module OR in the reference frame by the FTL Sending an optical burst test signal, where the optical burst test signal carries a transmission slot number;
  • the receiving port of the OR in the reference frame is based on the optical path difference between the output port of the FTL and the output port of the FTL in each line frame, and the optical burst test signal sent by the output port of the FTL of each line frame is received. And a time slot number carried by the optical burst test signal, obtaining a time phase difference between a receiving port where the OR in the reference frame is located and an output port where the FTL in each line frame is located, and The time phase difference of the output port where the FTL of the line frame is located is sent to the output port where the FTL of each line frame is located; The output port of the FTL of each line frame adjusts the clock phase referenced by the electrical burst data transmission on the output port where the FTL is located, according to the time phase difference.
  • An aspect of the present invention provides a line frame, including:
  • the receiving end electrical switching unit includes a plurality of receiving ports, a plurality of output ports, and a wavelength tunable optical transmitting laser FTL connected to each output port;
  • the switching unit includes a plurality of receiving ports, a plurality of output ports, and a light receiving module OR connected to each of the receiving ports;
  • the receiving port sends an optical burst test signal, so that the receiving port of the OR in the other line frame is received according to the optical path difference of the output port of the FTL in which the reference test signal is sent in the reference frame.
  • each of the ORs is located, when a line frame in another line frame connected to the same all-optical switching unit with the line frame is selected as a reference frame, received by the reference frame
  • the output port where the FTL is located passes the optical burst test signal sent by the FTL, and receives the light according to the optical path difference of the output port where the FLT of the optical burst test new signal is sent to the reference frame.
  • a line frame including:
  • the receiving end switching unit comprising a plurality of receiving ports, a plurality of output ports, and a wavelength tunable optical transmitting laser FTL connected to each output port;
  • the unit includes a plurality of receiving ports, a plurality of output ports, and a light receiving module OR connected to each of the receiving ports;
  • An output port of each of the FLTs configured to send a light burst from a line frame to a receiving port of an OR in a reference frame that is connected to the same all-optical switching unit and selected as a reference frame Testing a signal, and receiving a time phase difference between an output port where the FTL of the line frame sent by the receiving port in the reference frame is located and a receiving port where the OR in the reference frame is located, and according to the time
  • the phase difference adjusts a clock phase referenced by the electrical burst data transmission on the output port where the FTL is located; the optical burst test signal carries a transmission slot number; the time phase difference is
  • each OR is located, when the line frame is selected as a reference frame, and is sent by an output port of an FTL in another line frame connected to the same all-optical switching unit of the reference line frame.
  • the optical burst test signal and according to the optical path difference between the output port of the FTL in the other line frame, the time of receiving the optical burst test signal sent by the output port of the FTL of the other line frame, and the optical protrusion Sending a transmission slot number in the test signal, obtaining a time phase difference from an output port where the FTL in another line frame is located, and transmitting the time phase difference to an output port where the FTL in another line frame is located, so as to make other
  • the output port where the FTL in the line frame is located adjusts the clock phase referenced by the electrical burst data transmission on the basis according to the time phase difference.
  • An aspect of the present invention provides an optical network switching node of a multi-chassis cluster, including any one of the line frame and the all-optical switching unit provided by one aspect of the present invention
  • the all-optical switching unit includes: a plurality of input ends and a plurality of output ends; each output port of each of the receiving end electrical switching units is respectively connected to an input end of the all-optical switching unit through the connected FTL Connecting, each receiving port of each of the transmitting end electrical switching units is respectively connected to an output end of the all-optical switching unit through the connected OR;
  • Each of the receiving end electrical switching units is configured to receive, by using a plurality of receiving ports of the receiving end electrical switching unit, a plurality of data units, perform first-level electrical switching on the received multiple data units, and pass the The FTL connected to the plurality of output ports of the receiving end electrical switching unit is electrically and optically converted and output to the all-optical switching unit;
  • the all-optical switching unit is configured to perform all-optical space-segment exchange on the multi-channel data unit outputted by the receiving-end electrical switching unit, and output the same to the transmitting-end electrical switching unit;
  • the transmitting end electrical switching unit is configured to perform photoelectric conversion on the multi-channel data unit output by the all-optical switching unit through an OR connected to the plurality of receiving ports of the transmitting-end electrical switching unit, and then perform photoelectric conversion After the multiplexed data unit performs the second-stage electrical switching, the multiplexed data units are output through the plurality of output ports of the transmitting end electrical switching unit.
  • Another aspect of the present invention provides a multi-chassis cluster optical network switching node, including any of the line frame and all-optical switching unit provided by another aspect of the present invention
  • the all-optical switching unit includes: a plurality of input ends and a plurality of output ends; each output port of each of the receiving end electrical switching units is respectively connected to an input end of the all-optical switching unit through the connected FTL Connecting, each receiving port of each of the transmitting end electrical switching units is respectively connected to an output end of the all-optical switching unit through the connected OR;
  • Each of the receiving end electrical switching units is configured to receive, by using a plurality of receiving ports of the receiving end electrical switching unit, a plurality of data units, perform first-level electrical switching on the received multiple data units, and pass the The FTL connected to the plurality of output ports of the receiving end electrical switching unit is electrically and optically converted and output to the all-optical switching unit;
  • the all-optical switching unit is configured to perform all-optical space-segment exchange on the multi-channel data unit outputted by the receiving-end electrical switching unit, and output the same to the transmitting-end electrical switching unit;
  • the transmitting end electrical switching unit is configured to perform photoelectric conversion on the multi-channel data unit output by the all-optical switching unit through an OR connected to the plurality of receiving ports of the transmitting-end electrical switching unit, and then perform photoelectric conversion After the multiplexed data unit performs the second-stage electrical switching, the multiplexed data units are output through the plurality of output ports of the transmitting end electrical switching unit.
  • An optical burst synchronization method, a line frame, and an optical network switching node of a multi-frame cluster select a line frame as a reference frame from a plurality of line frames connected to the same all-optical switching unit, and The frame sends an optical burst test signal carrying the transmission time slot to other line frames, and the other line frames according to the optical path difference between the respective reference frame and the local time of receiving the optical test signal and the reference frame side carried in the optical test signal
  • the transmission time slots obtain the time phase difference between each of the reference frames and the local clock phase based on the time phase difference, so that the optical burst signals carrying the same time slot number transmitted by the respective line frames can reach the all-optical switching unit at the same time.
  • the optical burst synchronization is realized, and the switching mode of electric switching-all-optical space-splitting exchange-electrical switching is realized, and the low-power characteristics of all-optical space-splitting exchange are fully utilized, and the multi-frame clustering system based on OTN technology is realized.
  • the multi-chassis cluster increases the capacity of the OTN core node, improves the bandwidth utilization of the transport network, and solves the prior art.
  • the OTN electrical node is constrained by factors such as power consumption, heat dissipation, and load bearing capacity of the machine. It is difficult to achieve capacity expansion.
  • an optical burst synchronization method, a line frame, and an optical network switching node of a multi-chassis cluster select one line frame as a reference frame from a plurality of line frames connected to the same all-optical switching unit, and other lines
  • the frame respectively sends an optical burst test signal carrying a transmission slot to the reference frame, and the reference frame acquires and routes according to other line frames, the time when the optical burst test signal is received, and the transmission time slot carried by the optical burst test signal.
  • the time phase difference of the frame, and the obtained time phase difference is fed back to other line frames, so that other line frames perform local clock phase calibration according to the time phase difference, so that the optical burst signals carrying the same time slot number are sent by each line frame. It can simultaneously reach the all-optical switching unit, realizes optical burst synchronization, and realizes the exchange mode of electric-switching-all-optical space-switching-electrical switching, fully utilizing the low-power characteristics of all-optical space-switching, and realizes the basis
  • OTN technology multi-chassis cluster system increases the capacity of OTN core nodes and improves the transport network through multi-chassis clustering Bandwidth utilization, the prior art to solve the constraints OTN electrical node receiving machine power consumption, heat dissipation, and other factors bearing room, the problem is difficult to achieve expansion.
  • FIG. 1 is a schematic structural diagram of an optical network switching node of a multi-chassis cluster according to an embodiment of the present invention
  • FIG. 2 is a schematic structural diagram of an optical network switching node of a multi-chassis cluster according to another embodiment of the present invention
  • FIG. 3 is a schematic structural diagram of a part of an optical network switching node of a multi-chassis cluster according to an embodiment of the present invention
  • FIG. 4 is a flowchart of an optical burst synchronization method according to an embodiment of the present invention.
  • FIG. 5 is a flowchart of an optical burst synchronization method according to another embodiment of the present invention.
  • FIG. 6 is a schematic structural diagram of a circuit frame for implementing an optical burst synchronization method according to an embodiment of the present invention
  • FIG. 7 is a schematic structural diagram of a circuit frame for implementing an optical burst synchronization method according to an embodiment of the present invention.
  • the technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention.
  • the embodiments are a part of the embodiments of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.
  • FIG. 1 is a schematic structural diagram of an optical network switching node of a multi-chassis cluster according to an embodiment of the present invention.
  • the optical network switching node of this embodiment includes: at least one receiving end electrical switching unit 11, at least one all-optical switching unit 12, and at least one transmitting end electrical switching unit 13.
  • the mutually corresponding receiving end electrical switching unit 11 and the transmitting end electrical switching unit 13 are located in one line frame.
  • Each of the receiving end electrical switching units 11 includes a plurality of receiving ports 111, a plurality of output ports 112, and a fast wavelength tunable laser (FTL) 113 connected to each of the output ports 112;
  • the receiving end electrical switching unit 11 has the same number of receiving ports 111, output ports 112 and FTL 113, and has a corresponding relationship between the receiving port 111 and the output port 112 of each receiving end electrical switching unit 11.
  • Each of the transmitting end electrical switching units 13 includes a plurality of receiving ports 131, a plurality of output ports 132, and an optical receiving module (Optical Receiver; OR: 133) connected to each of the receiving ports 131; each transmitting end electrical switching unit 13 has the same number of receiving ports 131, output ports 132 and OR 133, and has a corresponding relationship between the receiving port 131 and the output port 132 of each transmitting end electrical switching unit 13.
  • each receiving end electrical switching unit 11 includes four receiving ports 111, four output ports 112, and an FTL 113 connected to each output port 112.
  • the four receiving ports 111 are respectively: a first receiving port, The second receiving port, the third receiving port and the fourth receiving port respectively comprise: a first output port, a second output port, a third output port and a fourth output port.
  • Each of the transmitting end electrical switching units 13 includes four receiving ports 131, four output ports 132, and an OR 133 connected to each receiving port 131; the four receiving ports 131 are also a first receiving port, a second receiving port, and a third The receiving port and the fourth receiving port are respectively a first output port, a second output port, a third output port, and a fourth output port.
  • All the first receiving ports have the same number, which is 1; all the second receiving ports have the same number, which is 2; all the third receiving ports have the same number, which is 3, all The number corresponding to the fourth receiving port is the same, which is 4. Similarly, all first output ports, all second output ports, all third output ports, and all fourth output ports have the same number, respectively 1, 2, 3, and 4.
  • the receiving port 111 and the output port 112 of the receiving end electrical switching unit 11 further include other circuits, and the receiving port 131 and the output port 132 of the transmitting end electrical switching unit 12 also include other circuits, which are used in FIG. A "rectangular box" is indicated.
  • Each all-optical switching unit 12 includes a plurality of input terminals 12a and a plurality of output terminals 12b.
  • the input end 12a and the output end 12b are the same in number and have a corresponding relationship.
  • Each output port 112 of each receiving end electrical switching unit 11 is connected to an input terminal 12a of an all-optical switching unit 12 via the connected FTL 113; each receiving port 131 of each transmitting end electrical switching unit 13 respectively Connected to an output 12b of an all-optical switching unit 12 via the connected OR 1313.
  • Each receiving end electrical switching unit 11 is configured to receive multiple data units through its multiple receiving ports 111, perform first-level electrical switching on the received multiple data units, and connect through multiple output ports 112 thereof.
  • the FTL 113 performs electro-optical conversion and outputs it to the all-optical switching unit 12.
  • the all-optical switching unit 12 is configured to receive, by its input end 12a, the electro-optical converted multi-channel data unit outputted by the receiving end electrical switching unit 11, and perform all-optical air separation on the received electro-optically converted multi-channel data unit The exchange is then output to the transmitting electrical switching unit 13 via its output 12b.
  • the transmitting end electrical switching unit 13 is configured to receive the multiple data units output by the all optical switching unit 12 through the OR 133 whose multiple receiving ports 131 and the receiving port 131 are connected, and perform the multiple data units output by the all optical switching unit 12
  • the photoelectric conversion is followed by the second-stage electrical exchange of the photoelectrically converted multiplexed data units, and then the multiplexed data units are output through the plurality of output ports 132 thereof.
  • the optical network switching node of the multi-chassis cluster of the present embodiment utilizes the switching mode of the electric switching-all-optical space-switching-electrical switching to fully utilize the low-power characteristics of the all-optical space-switching, and realizes the OTN-based technology.
  • the frame cluster system increases the capacity of the OTN core node through the multi-chassis cluster, improves the bandwidth utilization of the transport network, and solves the limitation of the OTN electrical node in the prior art by the power consumption, heat dissipation, and load bearing capacity of the whole machine. It is difficult to achieve the problem of expansion.
  • FIG. 2 is a schematic structural diagram of an optical network switching node of a multi-chassis cluster according to another embodiment of the present invention.
  • the all-optical switching unit 12 of this embodiment is an AWGR.
  • the output port 112 of each receiving end switching unit 11 is respectively connected to one input end of an AWGR 12 through the connected FTL 113, and the receiving port 131 of each transmitting end electrical switching unit 13 passes through the connected OR 133 respectively.
  • One output of the AWGR12 is connected.
  • the same numbered output ports 112 of all the receiving end electrical switching units 11 are respectively connected to different inputs of the same AWGR 12 through the connected FTL 113.
  • FIG. 1 the all-optical switching unit 12 of this embodiment is an AWGR.
  • the first output ports of all the receiving end electrical switching units 11 are connected to different inputs of the first AWGR 12 through the connected FTL, and the second output ports of all the receiving end electrical switching units 11 pass.
  • the connected FTL is connected to the different inputs of the second AWGR 12, and so on.
  • the same numbered receiving ports 131 of all the transmitting end electrical switching units 13 are respectively connected to different output ends of the same AWGR 12 through the connected OR 133, and the same number of all receiving end electrical switching units 11 connected to different inputs of the AWGR 12 are respectively connected.
  • the number of the output port 112 is the same as the number of the receiving port 131 of the same number of all the transmitting electrical switching units 13 connected to the different outputs of the AWGR 12. As shown in FIG.
  • the first receiving ports of all the transmitting end electrical switching units 13 are respectively connected to the different output ends of the first AWGR 12 through the connected OR, and the second receiving ports of all the transmitting end electrical switching units 13 pass through
  • the connected ORs are respectively connected to different outputs of the second AWGR 12, and so on.
  • the output port 112 of the receiving end electrical switching unit 11 connected to the FTL 113 (abbreviated as the output port 112 where the FTL 113 is located) is mainly responsible for generating an electrical burst signal, transmitting a reference clock timing indication, and converting the electrical light to the FTL 113. Electrical control of FTL wavelengths, etc.
  • the receiving port 131 of the transmitting end electrical switching unit 13 connected to the OR 133 (referred to as the receiving port 131 where the OR 133 is located) is mainly responsible for the conversion of the optical wave signal to the electrical signal.
  • the FTL113 is connected to the AWGR12 through the optical fiber, and the AWGR12 is connected to the OR133 through the optical fiber.
  • each receiving port 111 of the receiving end electrical switching unit 11 receives the multiplexed data unit, performs first-level electrical switching on the received multiplexed data unit, and outputs each output port 112 to the connected
  • the FTL 113 electrically and optically converts the electrical time division burst data unit after the first stage electrical exchange to form a time division optical burst signal, and sends the time division optical burst signal to the all optical switching unit 12, that is, the AWGR 12.
  • Each AWGR12 is configured to exchange time-division optical burst signals from different FTLs 113 on different time slots to different output terminals and send them to different transmitting end electrical switching units.
  • the transmitting end electrical switching unit 13 first receives the time division optical burst signal sent by the AWGR 12 from its OR 133, converts the time division optical burst signal into an electrical time division burst data unit, and then sends it to the receiving port 131 connected to the OR 133, and then A second level of electrical switching is performed, and finally an electrical time division burst data unit is output through its respective output port 132, thereby causing the electrical time division burst data unit to leave the cluster node.
  • the optical network switching node of this embodiment can logically correspond to the Charles three-level network.
  • a part of the receiving end electrical switching unit 11 (the part other than the FTL) may be the first stage of the Charles three-level network (ie, the three-stage CLOS switching network) (Stage 1 ; S 1 for short), and some of the transmitting ends are electrically
  • the switching unit 13 (the portion other than the OR) may be the third level of the three-stage CLOS switching network (Stage 3; abbreviated as: S3); and the intermediate all-optical switching unit 12 is combined with the receiving-end electrical switching unit 11
  • the OR in the FTL and the transmitting end electrical switching unit 13 may be the second level of the three-stage CLOS switching network (Stage 2; simply: S2).
  • the electrical time division burst data unit in this embodiment may be an ODU-k signal, and S1 and S3 may implement an electrical domain exchange of the ODU-k signal, and k may take any integer value from 0 to 4.
  • the receiving ports of S 1 and S3 ie, the receiving port 11 1 of the receiving end electrical switching unit 11 and the receiving port 131 of the transmitting end electrical switching unit 13
  • each S1 and each S3 includes 4 receiving ports, 4 receiving ports can transmit ODU-2 or OTU-2 signals, or 1 out of 4 receiving ports transmit ODU-3 or OTU-3 signals , other transmission ODU-2 or OTU-2 signals.
  • S1 can demultiplex the lower level signal data unit of the ODU-k signal, up to ODU-0, and perform non-blocking full exchange.
  • each ODU-k signal is burst-encapsulated by the output port where the FTL in S2 is located, and is sent by the FTL in S2 to the AWGR for all-optical switching on S2.
  • the receiving port of the OR in S2 completes the decapsulation of the burst-encapsulated ODU-k signal, the ODU-k is non-blocking full switching, and is encapsulated into the high-order ODU-k/OTU-k through the standard OTN interface. , leaving the cluster node.
  • AWGR is a core passive optical switching device commonly used in all-optical switching systems.
  • the main characteristic of AWGR is which output of a certain wavelength of optical burst signal is output from one of its inputs, depending on the wavelength of the optical burst signal itself; for example: different wavelengths input from the first input of AWGR
  • the optical burst signal will be output from different outputs of the AWGR; and the wavelength of the optical burst signal output to the same output is also different.
  • AWGR 4x4 multiple repetition period
  • Table 1 The meaning of Table 1 will be described by taking the first input terminal and the first output terminal as examples. That is, the optical burst signals of the wavelengths of ⁇ 1 ⁇ 5 ⁇ 4 ⁇ +1 input by the first input terminal are respectively outputted at the first output terminal, and the relationship between the first input terminal and the first output terminal can be analogized to other input terminals and output terminals.
  • the wavelengths of the optical burst signals outputted from the first output end to the fourth output end are respectively visible, and the wavelengths of the optical burst signals outputted from each output end are different.
  • AWGR is widely used in Wavelength Division Multiplexing (WDM) or Dense Wavelength Division Multiplexing (DWDM) networks to implement wavelength-level switching and corresponding switching.
  • WDM Wavelength Division Multiplexing
  • DWDM Dense Wavelength Division Multiplexing
  • the bandwidth granules are often large particle bandwidths of 10 Gbps, 40 Gbps, and 100 Gbps.
  • AWGR is applied to a multi-chassis cluster system as an all-optical switching unit of a multi-chassis cluster system to implement electrical switching-all-optical space-splitting exchange-electricity.
  • the three-level switching mode of switching makes full use of the advantages of AWGR with large bandwidth particles, and realizes a multi-chassis cluster system with all-optical switching.
  • AWGR is switched using passive optical devices, its power consumption is very low, and electrical switching Different nodes, AWGR is no longer limited by factors such as power consumption and heat dissipation. Compared with electrical switching nodes, AWGR is more flexible, further ensuring the development of multi-chassis cluster systems and laying the foundation for meeting the increasing traffic demand of the Internet. .
  • a receiving end electrical switching unit 11 and a transmitting end electrical switching unit 13 in the transport network system of the multi-chassis cluster are configured as uplink and downlink parts of an electrical switching unit (line frame).
  • the complete meaning of the electrical switching node unit is usually deployed in a line frame.
  • the Sl, the FTL connected to the S1, the S3, and the ROA connected to the S3 are deployed in the line frame; and the all-optical switching unit 12
  • the AWGR12 is usually deployed in a centralized cross box.
  • the cross-connection between the AWGR 12 and the FTL 121 is determined by the wavelength of the optical burst signal output by the FTL 113, that is, the cross-connect control in the all-optical switching unit 12 is actually converting the FTL into optical burst signals of different wavelengths.
  • Wavelength configuration control process For the transport network cluster system with 200 line frames, each AWGR receives 200 optical burst signals sent by the FTL. If the optical burst signals arrive at the AWGR and the local time of the AWGR is not If it matches, it will cause overlapping collision between the optical burst signals after the AWGR completes the space division exchange (that is, different burst signals of the same wavelength overlap and reach the OR at the same time, so the OR cannot correctly receive and process these signals). As a result, the transmitting end electrical switching unit cannot implement time division receiving, which causes the system to fail to transmit, or needs to deploy multiple receivers before the receiving end electrical switching unit to perform wavelength division receiving, which in turn increases system complexity and cost.
  • the problem of the synchronization between the optical burst signals of the optical network switching node of the multi-frame cluster is an important problem faced by the optical network switching node of the multi-frame cluster provided by the embodiment of the present invention.
  • the synchronization of the optical burst signals is called optical burst synchronization.
  • the following describes the all-optical exchange of the smallest particle ODU-0 in the ODU-2 as an example of the optical network switching node of the multi-chassis cluster shown in FIG.
  • each burst data packet is encapsulated with one ODU-0 data stream.
  • Each of the three consecutive optical bursts constitutes one frame, and each optical burst corresponds to one time slot, that is, one frame contains three time slots.
  • a multiframe contains 3xn slots, which can carry 3xn optical burst signals.
  • each line frame includes Sl, S3, FTL and OR, respectively, and only each line frame is shown in FIG.
  • An FTL of number 1 and an OR are FTL1 - 1, FTL2 - 1, FTL3 - 1, FTL4 1 and 0R1 - 1, 0R2 - 1, 0R3 - 1 , 0R4 - 1, respectively.
  • FTL1—1, FTL2—1, FTL3—1, and FTL4 1 are sequentially connected to the input of AWGR
  • OR1—1, OR2—1, OR3—1, and OR4 1 are sequentially connected to the output of AWGR.
  • any FTL or AWGR can be used as the reference point, and the local time of the reference point is used as the reference time, and other FTL or AWGR are aligned with the reference time.
  • the corresponding time slot number of the reference point time transmitted by the reference point is used as a reference to a local time point of the reference point, and the optical burst signal of the specific reference time phase reaches a point A.
  • the local time at the reference point corresponding to the slot number carried by the signal is recorded as the local time of the reference reference time of the location A (or the optical burst signal of the specific phase carrying the specific slot number transmitted by the location A arrives at the reference point,
  • the local time of point A when the point A transmits the signal is the local time of the reference point reference time, that is, the optical burst signal of the reference reference time.
  • the arrival time of the location A on the optical path is the local time referenced by the reference time (the difference between the local time and the reference time on the reference point, which is equal to the time taken by the optical signal to complete the reference point to point A) .
  • this example uses the local time of AWGR as the base time.
  • the line frame 1 S1 and S3 of 2, 3, and 4 are consistent between the local time of the AWGR and the reference time of the AWGR (that is, the local time of the AWGR), and the output port of the FTL of each line frame transmits an optical burst signal with reference to the local time of each line. Arrived at the same time of the local time of the AWGR to meet the burst signal synchronization requirements of the system.
  • the uplink time difference between FTL1 - 1 and AWGR is 6.3 optical time slots
  • the uplink time difference between FTL 2-1 and AWGR is 7 optical time slots
  • the uplink time difference between FTL 3-1 and AWGR is 5.7.
  • the optical time slot, the uplink time difference between FTL 4-1 and AWGR is 7.4 optical time slots.
  • the wavelength configuration of each FTL is as shown in Table 2. Table 2
  • FTL1-1 is configured with the following wavelengths and connection relationships: (1) Line frame 1 is connected to the first input of AWGR through the FTL1-1 to the third output of AWGR (ie OR3—1) to the line. Block 3 establishes a sub-wavelength connection based on the first time slot and a reverse connection of line frame 3 to line frame 1. (2) Line frame 1 is connected to AWGR via FTL1 1 The first input to the second output of the AWGR (OR2 - 1 ) to the line frame 2 establishes a sub-wavelength connection based on the second time slot; and a reverse connection of the line frame 2 to the line frame 1.
  • Line frame 1 is connected to the first input of AWGR via FTL1 - 1 to the 4th output of AWGR (OR4 - 1 ) to line 4 to establish a sub-wavelength connection based on the 3rd time slot; and the line frame 4 to a reverse connection of line box 1.
  • the other FTLs are similar to this, where idle means that no connection establishment is made on this time slot.
  • the transmission of the optical burst signal of the next time slot is being prepared;
  • the FTL3-1 of the optical path of 5.7 optical time slot from the AWGR is transmitting the third of the first frame of the (N+1)th multiframe.
  • the optical burst signal of the time slot; the FTL 4-1 having the optical path of the 7.4 optical time slot from the AWGR is transmitting the optical burst signal of the second time slot of the second frame of the (N+1) multiframe.
  • each FTL to AWGR optical path forms a reasonable compensation match with each FTL local time.
  • the third time slot of the second last frame of the Nth multiframe from each FTL Has passed through AWGR, the last frame of the Nth multiframe from each FTL An optical burst signal coming slot.
  • FTL 1-1 is at AWGR local time
  • FTL 2-1 is at AWGR local time
  • FTL 3-1 is at AWGR local time
  • FTL 4-1 is at AWGR local time
  • four are at AWGR
  • the optical burst signals of the space division switching are completed on the AWGR. Even after different optical paths, the local time of each OR is synchronized, and there is no overlapping collision problem of the burst signals.
  • the optical buffer storage device is still immature and expensive, and the optical buffer using the optical fiber as the basic delay device has limited buffering capacity, large volume and high cost, and is particularly unsuitable for the multi-frame cluster system.
  • the solution needs to perform photoelectric conversion first, then perform electrical storage, and then undergo electro-optical conversion to output to the next stage, and the processing is relatively Complex, costly, and power consuming, it is also not suitable for multi-chassis cluster systems that are relatively sensitive to power consumption.
  • the multi-chassis cluster system the following embodiment of the present invention provides a solution for optical burst synchronization of optical network switching nodes based on FTL and AWGR for large-capacity multi-chassis clusters.
  • FIG. 4 is a flowchart of an optical burst synchronization method according to an embodiment of the present invention. As shown in FIG. 4, the optical burst synchronization method of this embodiment includes:
  • Step 401 Select a line frame as a reference frame from a plurality of line frames connected to the same all-optical switching unit.
  • the all-optical switching unit is taken as an example of AWGR.
  • the synchronization described in this embodiment refers to all the optical burst signals carrying the same slot number that are sent to the same AWGR through the FTL and arrive at the AWGR at the same time. Therefore, this embodiment describes each AWGR. As shown in Figure 3, there are 4 line frames connected to the same AWGR. This embodiment can select any one of the line frames as the reference frame.
  • Step 402 The output port where the FTL in the reference frame is located sends an optical burst test signal to the receiving port where the OR of the plurality of line frames connected to the same all-optical switching unit is located, where the optical burst test signal carries Send the slot number.
  • the corresponding FTL and OR connected to the same AWGR are located in the same line frame, as shown in FIG.
  • the FTL location output port in the reference frame may send optical burst test signals to multiple line frames connected to the same AWGR (including the reference frame) one by one in different burst overhead time slots;
  • the receiving port where the OR is located receives the optical burst test signal on different burst overhead time slots.
  • all the line frames are aligned to the time of the reference frame based on the time of the reference frame.
  • the output port of the FTL in the reference frame carries the transmission of the optical burst test signal in the transmitted optical burst test signal.
  • Send the slot number Since the transmission of various optical burst signals is based on the burst slot in the entire system, the present embodiment directly carries the transmission slot number to indicate that the optical burst test signal is at the output port of the FTL of the reference frame. Which time point is sent.
  • Step 403 The receiving port of the OR in each line frame connected to the same all-optical switching unit is based on the optical path difference of the output port where the FTL in the reference frame is located, and the time point at which the optical burst test signal is received.
  • the transmission time slot number carried in the optical burst test signal, the local time phase referenced by the electrical burst signal received on the receiving port where the OR is located, and the optical burst overhead burst signal sent from the reference frame via the FTL The difference between the reference time phases (ie, the time phase difference), and according to the time phase difference, the clock phase referenced by the receiving port on which the OR is located is adjusted, and according to the OR to the corresponding FTL in the same line frame.
  • the optical path difference adjustment OR corresponds to the clock phase referenced by the electrical burst data transmission on the output port of the FTL located in the same line frame.
  • the receiving port where the OR is located aligns the time of its local clock to the time indicated by the arrival time of the reference burst signal carrying the reference slot number, and correspondingly corrects the burst on the transmitting port where the FTL is located. Send the data to the referenced clock to the correct time.
  • the receiving port of the OR in each line frame connected to the same AWGR receives the optical burst test signal, it records the time when the optical burst test signal is received, that is, the local port where the receiving port of the OR receives the electrical burst data.
  • the arrival time is specifically characterized by the value (slot/pulse) of the counter of the clock to which the OR receives the reference.
  • the receiving port of the OR in each line frame connected to the same AWGR has previously obtained the optical path difference between the output ports of the corresponding FTLs in the same line frame, and the optical path is obtained.
  • the difference is specifically the transmission time required for the optical burst test signal to transmit the optical burst test signal to the receiving port where the OR is located from the output port where the corresponding FTL of the same line frame of the OR is located, usually the optical path difference It is fixed.
  • the receiving port of the OR of each line frame is based on the optical path difference and the optical path between the arrival time of the optical burst test signal, the receiving port where the OR is located, and the output port of the FTL of the same line frame corresponding to the OR.
  • the output port where the FTL is located refers to the time when the optical burst signal sent from the local clock time reaches the AWGR and the time when the optical burst signal carrying the same slot number sent from the output port reference reference time of the reference frame FTL arrives at the AWGR. Are the same.
  • the output port of the FTL carried by the signal is consistent at the time when the sending slot number of the signal is sent.
  • the local clock time referenced by the receiving port where the OR is located and the output port where the FTL is located transmit data.
  • the difference between the local clock times referenced is exactly equal to the transmission time consumed by the optical burst test signal from the output port where the FTL is located to the receive port where the OR is located.
  • the same local reference clock can be shared. If the receiving port where the OR is located receives the expected time point of the transmission slot number carried by the burst signal from the reference frame and the receiving port where the signal arrives at the OR, the clock time referenced by the receiving port of the OR is inconsistent. Correspondingly, the clock referenced by the output port of the FTL corresponding to the OR corresponding to the OR is not synchronized with the reference frame, and the optical burst signal sent by referring to the clock may be related to the FTL of the reference frame. The optical burst signal sent by the output port is in conflict.
  • the design expectation value of the local time referenced by the receiving port where the OR of the burst signal arrives from the reference frame is indicated by the time point identified by the transmission slot number carried by the burst signal.
  • the receiving port where the OR is located can be used to adjust the count value of the time counter of the local clock referenced by the receiving signal, and realize the adjustment of the time phase of the clock referenced by the receiving port of the OR itself.
  • the fixed time difference That is, the optical path difference between the receiving port where the OR is located and the output port of the FTL corresponding to the OR corresponding to the OR.
  • the optical path difference between the receiving port of the OR in the same line frame and the output port where the FTL is located can be known first. Therefore, the receiving port where the OR is located can also be sent to the output port of the corresponding FTL located in the same line frame at the same time. The phase time referenced by the data is adjusted.
  • optical path difference between the receiving port of the FTL/OR pair and the output port of the FTL corresponding to the OR corresponding to the OR in the line frame of the FTL/OR pair is referenced to the local port of the receiving port where the OR is located.
  • the clock phase adjusts the clock phase of the output port where the FTL located in the same line frame corresponds to the OR.
  • the process of adjusting the clock phase is specifically: correcting the time of the local clock referenced by the receiving port where the OR is located to the design expected time indicated by the arrival time of the carrying time slot burst signal from the reference line frame, and according to the OR
  • the optical path difference between the receiving port and the output port of the FTL corresponding to the OR corresponding to the OR in the same line frame further corrects the time of the local clock referenced by the output port where the FTL is located to a desired time.
  • a reference frame is selected from multiple line frames connected to the same AWGR, and the output port where the FTL of the reference frame is located is sent to other line frames by referring to its local reference clock.
  • the optical burst test signal carrying the slot number is determined by the receiving port of the OR of the other line frame according to the transmission slot of the optical burst test signal, the arrival time, and the light between the FTLs in the same line frame corresponding to the OR.
  • the path difference, adjusting the local clock referenced by the receiving and transmitting ports of the OR and FTL can realize the phase alignment between the line frames in the optical network switching node of the multi-frame cluster, thereby causing the optical burst signals emitted by the respective line frames. Arriving at AWGR at the same time, the synchronization of the system is realized, and the collision problem caused by the synchronization is solved.
  • the optical path difference may be used at the receiving port where the OR is located.
  • the output port of the FTL located in the same line frame corresponding to an OR may send an optical burst loopback signal to the receiving port where the OR is located.
  • the optical burst loopback signal carries a transmission slot number.
  • the receiving port of the OR is obtained according to the time of the received optical burst loopback signal and the sending slot number carried in the optical burst loopback signal, and the output port of the FTL corresponding to the OR in the same line frame is obtained.
  • the method for obtaining the optical path difference is not limited to this type, for example, the optical burst burstback signal is sent by the receiving port where the OR is located to the output port where the corresponding FTL is located.
  • the time is counted because the clock counter of each line frame is dependent on the count pulse of the nominal frequency generated by the local crystal oscillator.
  • the actual frequency of these crystal oscillators is stored between the nominal frequency and the nominal frequency.
  • a high frequency crystal oscillator will cause the phase to lead and accumulate over the time phase of the reference frame.
  • the receiving port of the OR line in each line frame connected to the same AWGR receives the reference light burst from the reference line frame in two consecutive times or more (multiple times) according to a preset detection period.
  • the receiving port where OR is located refers to the clock pulse generated by the local crystal frequency and records the counting result, and according to the difference between the two counting results and the expected design value (the time of two or more multiframe periods)
  • the difference between the lengths, the clock referenced by the receiving port where the OR is located, and the clock corresponding to the output port of the FTL corresponding to the OR in the same line frame are based on the clock counter generated by the local crystal frequency.
  • the optical burst test signal is periodically sent, and the transmission period of the optical burst test signal is generally smaller than the phase detection period (two or more reference burst signal periods are sequential detection periods).
  • the transmission period of the optical burst test signal is in the order of milliseconds, and the phase detection period is generally in the order of seconds. That is to say, at intervals, the local clock oscillation frequency is compared with the frequency of the reference frame to detect the frequency difference and the variation (drift) of the difference. According to the result of the detection, the specific pulse number of the control of the throughput pulse is updated, and the difference of the crystal frequency depending on the clock count of each line frame and the reference frame is updated and compensated in real time. For obvious frequency differences, compensation is achieved by throughput pulses; for subtle differences that are difficult to compensate by throughput pulses, it is ensured that the phase difference caused by the local clock oscillation frequency drift is made once every other time according to the preset phase detection period. Calibration compensation.
  • each line frame can use a clock pulse generated based on an oscillation frequency of a higher frequency local clock to perform a local clock pulse between two arrival times of two or more optical burst test signals from a reference frame.
  • Counting the higher the frequency, the more accurately the difference and drift can be detected. If consecutive two or more (n is greater than or equal to 2) optical burst test signals reach the same count result at the same time and are consistent with the design expectations, indicating that the local clock oscillation frequency meets the design expectations and does not drift, nor Because drift produces additional phase differences. If two or more consecutive (n is greater than or equal to 2) optical burst test signals, the count results between the arrival times are different and are different from the design expectations, indicating the local clock oscillation frequency and the reference frame frequency.
  • the local time counter is generated by counting the local clock to perform the swallow pulse or the spit pulse processing to realize the frequency difference. Compensation absorption adjustment.
  • the time phase of the line frame can be pulsed, so that the counter counts several pulses and then travels, thereby realizing Compensation for the difference between the crystal frequency and the reference frame crystal frequency.
  • the time phase of the line frame is swallowed, so that the counter counts a few pulses and is carried. In this way, the accuracy of phase synchronization can be further improved.
  • FIG. 5 is a flowchart of an optical burst synchronization method according to another embodiment of the present invention. As shown in FIG. 5, the method in this embodiment includes:
  • Step 501 Select a line frame as a reference frame from a plurality of line frames connected to the same all-optical switching unit.
  • the all-optical switching unit is also taken as an example of AWGR.
  • This step is similar to step 401 and will not be described here.
  • Step 502 The output port of the FTL in each line frame connected to the same all-optical switching unit sends an optical burst test signal to the receiving port where the OR in the reference frame is located in different overhead time slots.
  • the burst test signal carries a transmission slot number.
  • the output ports of the FTLs in all the line frames connected to the same AWGR respectively send optical burst test signals to the receiving ports where the ORs in the reference frame are located.
  • the actual arrival time and expectation of the local clock referenced by the receiving port where the OR is located in the reference frame is detected by the receiving port where the OR of the reference frame is located, and the optical burst test signal carrying the slot number sent by the corresponding port of each line frame is sent by the FTL.
  • the difference between the arrival times is obtained, and the desired phase difference of each line frame transmission port with respect to the reference frame is obtained.
  • Step 503 A light burst test signal sent by the receiving port where the OR in the reference frame is located according to the optical path difference between the output port where the FTL is located in each line frame and the output port where the FTL of each line frame is received. Time and the transmission slot number carried by the optical burst test signal, obtaining the time phase difference between the receiving port where the OR in the reference frame is located and the output port where the FTL in each line frame is located, and will be associated with each line The time phase difference of the output port where the FTL of the frame is located is sent to the output port where the FTL of each line frame is located.
  • the actual phase difference between the actual transmission line of each line frame and the reference frame is Different, the receiving port of the OR in the reference frame receives the transmission slot number carried by the FTL according to the corresponding port of each line frame (corresponding to the time when the sending port refers to its local clock time and sends the optical burst test signal through the FTL) The actual arrival time of the optical burst test signal, obtain the output port of the FTL in each line frame, refer to the burst signal sent by the FTL according to the local clock time, and refer to the receiving port where the reference line frame OR and OR are located.
  • the time phase difference between the actual arrival time of the local time of the port and the expected arrival time of the design, and the time phase difference of the clock time referenced by the output port where the FTL of each line frame is located is sent to each line frame separately.
  • the port where the FTL is located is sent to each line frame separately.
  • the OR of the reference frame When there is a time phase difference between the FTL of the line frame and the OR of the reference frame, the OR of the reference frame sends the time phase difference to the FTL of the line frame.
  • Step 504 The FTL of each line frame adjusts the clock phase of the FTL itself according to the time phase difference.
  • the FTL that receives the time phase difference adjusts its own clock phase based on the time phase difference. If the time phase difference indicates that the clock phase of the FTL itself is ahead, the clock time counter of the output port where the FTL is located is reduced by the count value corresponding to the time phase difference. If the time phase difference indicates that the clock phase of the FTL itself is lagging, the clock time counter of the output port where the FTL is located is incremented by the count value corresponding to the time phase difference to achieve phase alignment.
  • a reference frame is selected from a plurality of line frames connected to the same AWGR, and the FTL in each line frame sends an optical burst test signal to the reference frame, which is ORed by the reference frame.
  • the receiving port is located according to the difference between the sending time slot of the optical burst test signal, the actual arrival time, and the expected arrival time on the port where the reference frame OR is located, and obtains the reference clock time and alignment of the data sent by the port where each line frame FTL is located.
  • the expected clock time phase difference of the reference frame is fed back to each line frame, and each line frame is time-phase adjusted according to the time phase difference, and the phase alignment between the line frames can be realized in the optical network switching node of the multi-frame cluster. Therefore, the optical burst signals sent by the respective line frames reach the AWGR at the same time, thereby realizing the synchronization of the system, and solving the collision problem caused by the asynchronous.
  • the FTL in each line frame connected to the same AWGR is located.
  • the output port refers to the local clock time, and repeatedly sends the burst overhead signal on the overhead time slot corresponding to the frame number according to the preset multiframe period, and the port where the OR in the reference frame is located is sent twice or more times in the same line frame. The difference between the actual arrival time of the burst signal on the port where the reference line frame OR is located and the expected arrival time of the reference frame.
  • the crystal frequency of the line frame is not different from the reference frame crystal frequency, and there is no difference.
  • Drift if there is a change, the difference will become larger and larger with time, we call the relative drift in phase due to the difference in crystal frequency.
  • compensation is achieved by throughput pulses; for subtle differences that are difficult to compensate by throughput pulses, it is ensured that the identifiable phase difference caused by the local clock oscillation frequency drift is performed once every other time according to the preset phase detection period. Calibration compensation.
  • the reference line frame is based on a reference clock counter of the port where the reference frame OR of the higher frequency clock counting pulse is counted, and if the difference between the actual arrival time and the expected arrival time of different bursts of the same line frame is consistent, It indicates that the local clock of the FTL and the reference line frame have the same oscillation frequency and no frequency drift occurs, and no additional phase difference is generated. If two or more consecutive descriptions of the clock phase difference between the arrival time and the expected arrival time are different, indicating that the oscillation frequency of the local clock is different, and phase shift occurs, it is necessary to according to the two actual arrival times and the expected arrival time.
  • the difference between the differences is counted by updating the local clock referenced by the output port where the FTL is located to generate a local time counter for swallowing or spitting, thereby realizing phase adjustment. In this way, the accuracy of phase synchronization can be further improved.
  • optical burst synchronization method provided by the present invention is described in principle in the foregoing embodiment of FIG. 4 or FIG. 5. The following embodiment will further describe the optical burst synchronization method of the present invention in combination with an actual application scenario.
  • the corresponding S1 and S3 are deployed in the same line frame.
  • the line frames 1, 2, 3, and 4 respectively include an S1 and an OR, and each SI is connected to one FTL, and each S3 is connected to one OR. That is, an FTL corresponds to an OR and is deployed in the same line frame.
  • an FTL corresponds to an OR and is deployed in the same line frame.
  • the nominal frequency can be 38.88 megahertz (MHz) or 155.52 MHz or 311.04 MHz.
  • each line frame there will be at least one clock and synchronization module in each line frame for counting the clock pulses of the nominal frequency, resulting in various time periods and boundaries required for each line frame, such as local on the transmitting side. Reference clock time and local reference clock time on the receiving side.
  • the nominal frequency is 38.88MHz, that is, it will be generated in one second.
  • the reservation interval is referred to as a burst interval (BurstGap).
  • a time slot containing 600 clock pulses can use the first 100 clock pulses and the last 100 clock pulses as burst intervals, and the middle 400 clock pulses to transmit optical burst signals.
  • the time slot number (ID) of the time slot in the multiframe can be counted by carry.
  • the clock and synchronization module in each line frame provides a working reference clock for S1 and FTL, and also provides a clock-based count value output for indicating the transmission boundary of the optical burst signal (start / End) and slot boundaries (start/end), and also provide conditions for the arrival times of the S3 and OR recording optical burst signals.
  • the present embodiment selects the line frame 1 as the reference frame.
  • a method for specifically implementing optical burst synchronization includes:
  • FTL1 - 1 in line frame 1 sends optical burst test signals to OR1 - 1, OR2 1, OR3 - 1 and OR4 - 1 in line blocks 1, 2, 3 and 4, respectively.
  • four overhead frames are defined to form one overhead multiframe, and each overhead frame includes 81 slots, wherein one slot in each overhead frame is used to send an optical burst test signal,
  • For overhead time slots the location of the overhead time slots in each overhead frame is fixed; each time slot includes 600 clock pulses.
  • the overhead time slot of the 0th frame of the overhead multiframe is allocated to the reference frame spontaneously; the overhead time slot of the 1st frame of the overhead multiframe is allocated to the two-way communication between the line frame 1 and the line frame 2 (including the transmission and the transmission) Receiving); the overhead time slot of the second frame of the overhead multiframe is allocated to the two-way communication between the line frame 1 and the line frame 3; the overhead time slot of the third frame of the overhead multiframe is allocated to the line frame 1 and the line frame 4 Two-way communication between.
  • the overhead multiframe contains the number of overhead frames greater than or equal to each AWGR.
  • the number of connected line frames For example: When an AWGR is connected to 200 line frames at the same time, at least 200 overhead frames need to be defined to form an overhead multiframe.
  • the method for allocating each overhead frame is the same as described above.
  • OR4—1 sends an optical burst test signal, and carries the slot number of the optical burst test signal in the optical burst test signal.
  • only one OR of the line frame (including the reference frame itself) and the line frame 1 are in two-way communication.
  • optical burst test signals transmitted from line frame 1 (as the reference line frame) over the overhead time slots of different overhead frames are periodically received.
  • OR1—1, OR2—1, OR3 1 and OR4—1 in line frames 1, 2, 3 and 4 respectively record the local system time when the optical burst test signal is received.
  • the local system time is determined by the line frame 1.
  • the clock and synchronization module in 2, 3 and 4 counts the local crystal oscillator for ORl-1, OR2-1, OR3-1 and OR4-1, and the recorded local system time is the optical burst test signal. Arrival time.
  • OR1_1, OR2-1, OR3-1, and OR4-1 in line frames 1, 2, 3, and 4 are based on the arrival time of the recorded optical burst test signal, from the line
  • the slot number carried in the reference optical burst test signal of block 1 calibrates the local system clock time referenced by the respective OR.
  • the local system time on the FTL2-1, FTL3 1 and FTL4-1 sides in the same line frame can also be calibrated.
  • the local system time on the OR side of the same line frame can be the delayed output of the FTL's local system time. That is, the OR needs to increase the time difference when calibrating its local system time by a corresponding delay and then calibrate the same line.
  • the local system time of the FTL in the box. Delay is the optical path difference between OR and FTL in the same line frame.
  • OR1-1, OR2-1, OR3 1 in the line frames 1, 2, 3 and 4 The optical path difference between OR and 4-1 and FTL 1-1 in line frame 1 is known in advance.
  • the optical path difference between OR1—1, OR2—1, OR3 1 and OR4—1 in line frames 1, 2, 3 and 4 and FTL1—1, FTL2—1, FTL3—1 and FTL4–1, respectively, is also Known.
  • the optical burst test signal sent on the overhead slot can implement back and forth communication between any line frames, which can be directly completed by hardware. Synchronous control eliminates the need for software and network management intervention, thus solving the problem of limited software processing speed.
  • one of the overhead time slots in each overhead multiframe can be defined as a loopback time slot, not only the reference frame.
  • An overhead burst is sent to the first block (itself) within the time slot, and each line frame sends a loopback overhead burst to itself. It is used for the FTL in each line frame to send an optical burst loopback signal to the OR in the line frame to test the optical path difference between FTL and OR in the same line frame in real time. More preferably, the loopback time slot is the first overhead time slot.
  • FTL1—1, FTL2—1, FTL3 1 and FTL4—1 in the line 1, 2, 3 and 4 respectively go to OR1—1, OR2 in their respective loopback time slots.
  • OR3 1 and OR4—1 send an optical burst loopback signal, and carry the slot number of the optical burst loopback signal in the optical burst loopback signal.
  • the OR1—1, OR2—1, OR3 1 and OR4—1 in the circuit 1, 2, 3 and 4 record the arrival time of the optical burst loopback signal, which will be carried in the arrival time and the optical burst loopback signal.
  • the time points corresponding to the time slot number are poor, and the optical path difference between them is obtained, which is OR1—1, OR2—1, OR3 1 and OR4—1 for FTL1—1, FTL2—1, FTL3 1 and FTL4-1, respectively.
  • the local system time is calibrated to lay the foundation.
  • a line frame will contain multiple FTLs and multiple ORs, and each FTL and corresponding OR will connect to different AWGRs.
  • Each AWGR corresponds to a plane, and the planes are irrelevant. That is to say, synchronization is required between the FTL and the OR connected to the same AWGR, and the synchronization is not related to the FTL and OR of other AWGRs.
  • a receiving port in which an OR is located is selected from each line frame for synchronization.
  • the receiving port where the OR is located may receive multiple optical burst signals, so the receiving port where the OR is located may first filter all optical burst signals received by the OR, and extract optical burst loopback signals and optical bursts therefrom. Test signal.
  • the time of arrival of the two signals and the two letters can be The time slot number carried in the number is sent to the clock and synchronization module, and the time is calibrated by the clock and synchronization module.
  • the natural frequencies of the local crystal oscillators of each line frame are inconsistent with each other (there are differences), and may also drift with changes in temperature, etc., such differences and drifts are caused.
  • the actual length of the clock unit generated based on the frequency counts that occur is different on each line frame.
  • the present embodiment provides a method of suppressing the difference in the natural frequency of the local crystal oscillator and the actual length and phase variation and drift of the clock unit caused by the drift.
  • the receiving port of the OR in each line frame can use a higher frequency clock pulse to count the higher frequency local crystal frequency pulse between two or more optical burst test signals and record the counting result, and obtain at least Two counting results are then judged whether or not crystal oscillation drift occurs by judging whether at least two counting results are the same, and time calibration is performed according to the difference of the counting results.
  • the operation of counting the time interval between the two optical burst test signals may be performed once every time, that is, periodically performing the counting operation according to the preset phase detection period, and detecting the two phases by The counting result obtained by the cycle is compared to determine whether phase adjustment is needed, which can alleviate the overhead and burden of the entire system. Still taking the line frame 2 in FIG.
  • OR2 - 1 in the line frame 2 counts the local crystal oscillator between the two optical burst test signals at intervals (for example, one second). After counting the results, the two count results are compared. For example: If the first counting result counts 9,720,000 clock pulses, the second counting result is 9,720,000+9.72 clock pulses, and the two counting results are different before and after, indicating that the clock frequency of the local crystal of line frame 2 has drifted. It is 1ppm faster than before, so it is necessary to compensate for this frequency deviation, and the local clock and the synchronization module's slot count are calibrated by the throughput pulse.
  • FIG. 6 is a schematic structural diagram of a circuit frame for implementing an optical burst synchronization method according to an embodiment of the present invention.
  • the circuit frame of this embodiment includes: a receiving end electrical switching unit 61 and a transmitting end electrical switching unit 62.
  • the receiving end electrical switching unit 61 includes: a plurality of receiving ports 611, a plurality of output ports 612, and an FTL 613 connected to each of the output ports 612.
  • the transmitting end electrical switching unit 62 includes: a plurality of receiving ports 621, a plurality of output ports 622, and an OR 623 connected to each of the receiving ports 621.
  • the output port to which the FTL is connected is also referred to as the output port where the FTL is located; the receiving port to which the OR is connected is also referred to as the receiving port where the OR is located.
  • a line frame often contains several pairs of FTL613 and OR623 port pairs. Among them, each FTL613
  • the output port 612 is configured to send an optical burst test signal to the receiving port where the OR of the reference line frame connected to the other all-optical switching unit of the same all-optical switching unit is selected when the line frame is selected as the reference frame.
  • the receiving port of the OR in the other line frame receives the optical burst according to the optical path difference of the output port 612 where the FTL 613 transmitting the reference test signal in the reference frame is located, and the receiving port of the other line frame.
  • the actual time of the test signal and the transmission time slot number carried by the optical burst test signal are compared with the local reference clock referenced by the interface data of the interface of the other line frame, and the reference burst test signal from the reference frame is obtained.
  • the phase difference between the arrival phase of the receiving port where the OR of the other line frame is located and the local receiving reference time of the receiving port where the OR of the other line frame is located (referred to as the time phase difference from the output port where the FTL in the reference frame is located) And adjusting the time when the receiving port of the OR in the other line frame receives the burst data according to the acquired time phase difference And OR output phase with the other lines in the same frame of the frame corresponding to the line FTL burst data transmission port where the reference clock phase.
  • the receiving port 621 of each OR623 is configured to receive the output of the FTL in the reference frame when a line frame in another line frame connected to the same all-optical switching unit of the line frame is selected as the reference frame.
  • the optical burst test signal sent by the port through the FTL, and the optical path difference of the output port where the FTL of the optical burst test signal is sent according to the receiving port 621 where the OR623 is located, and the actual output of the optical burst test signal are received.
  • the transmission time slot number carried by the time and optical burst test signal is compared with the local reference clock referenced by the receiving port 621 where the OR 623 receives the burst data, and the reference burst test signal from the reference frame is obtained at the OR623.
  • the phase difference between the arrival phase of the receiving port 621 and the local receiving reference time of the receiving port 621 where the OR623 is located (referred to as the time phase difference of the output port where the FTL of the optical burst test signal is transmitted in the reference frame), and according to the time
  • the phase difference adjusts the clock phase referenced by the receiving port 621 where the OR623 is received, and the OR623
  • the corresponding output port 612 of the FTL 613 located in the same line frame transmits the clock phase referenced by the burst data.
  • the receiving port 621 of the OR623 in the line frame of the embodiment is specifically configured according to the time phase difference between the output port where the OR623 is located and the output port 612 of the FTL 613 located in the same line frame corresponding to the OR623.
  • the optical path difference is adjusted, and the output port 612 of the FTL 613 located in the same line frame corresponding to the OR623 is sent to send burst data.
  • the reference clock phase (or the clock phase referenced by the burst data transmission).
  • the node device in this embodiment can be used to perform the process of the optical burst synchronization method shown in FIG. 4, and the specific working principle is not described here. For details, refer to the description of the method embodiment.
  • the output port 612 of the FTL 613 of the line frame of the embodiment is further configured to send an optical burst loopback signal to the OR623 of the same line frame corresponding to the FTL 613 via the connected FTL 613, where the optical burst loopback signal carries There is a transmission slot number.
  • the receiving port 621 of the OR623 of the circuit frame in this embodiment receives the optical burst loopback signal, and acquires according to the time of receiving the optical burst loopback signal and the sending slot number carried by the optical burst loopback signal.
  • the OR623 corresponds to the optical path difference between the output ports 612 of the FTL 613 located in the same line frame.
  • the receiving port 621 where the OR623 is located combines the acquired time phase difference with the optical path difference between the output port 612 where the FTL 613 is located and the receiving port 621 where the OR 623 is located, and adjusts the clock phase referenced by the output port 612 where the FTL 613 is located.
  • the receiving port 621 of the line frame of the circuit frame provided by the embodiment further calculates the local clock counting result and the designed expected value between two consecutive times or multiple times of receiving the optical burst test signal according to the preset phase detecting period.
  • the difference between the receiving port 621 where the OR623 is located receives the clock phase referenced by the burst data (or adjusts the clock phase referenced by the burst data reception on the receiving port 621 where the OR623 is located, or adjusts the OR623
  • the clock phase of the receiving port 621 indicates the number of counting beats of the counter time unit), and adjusts the clock phase of the output port 612 of the FTL 613 located in the same line frame corresponding to the OR623 to indicate the number of counting beats of the counter time unit (or
  • the clock phase referenced by the burst data transmission on the output port 612 where the FTL 613 is located is adjusted, thereby correcting the inconsistency of the time unit length on each line frame.
  • the all-optical switching unit can be implemented by the AWGR, but is not limited thereto.
  • control and management functions in the above optical burst synchronization process can be implemented by a central processing unit (CPU) and a software subsystem in the line frame.
  • CPU central processing unit
  • the reception and transmission of the optical burst test signal can be done by the CPU and the software subsystem; and the acquisition of the time phase difference and the adjustment of the clock phase can be done by the clock and the synchronization module.
  • the input of the FTL of the reference frame is received.
  • the optical burst test signal sent by the outbound port is obtained by the receiving port of the OR according to the optical path difference between the sending time slot of the optical burst test signal, the arrival time, and the output port of the FTL in the line frame.
  • the time phase difference between the line frame and the reference frame in this embodiment, the OR of the line frame according to the time phase difference is the time phase referenced by the receiving port receiving the burst data and the time phase referenced by the FTL output output port transmitting the burst data.
  • the adjustment can realize the phase alignment between the line frames in the optical network switching node of the multi-frame cluster, so that the optical burst signals carried by the respective line frames carrying the same time slot number arrive at the AWGR at the same time, thereby realizing
  • the synchronization of the system solves the collision problem caused by the synchronization.
  • FIG. 7 is a schematic structural diagram of a circuit frame for implementing an optical burst synchronization method according to an embodiment of the present invention.
  • the circuit frame of this embodiment includes: a receiving end electrical switching unit 71 and a transmitting end electrical switching unit 72.
  • the receiving end electrical switching unit 71 includes: a plurality of receiving ports 711, a plurality of output ports 712, and an FTL 713 connected to each of the output ports 712.
  • the transmitting end electrical switching unit 72 includes: a plurality of receiving ports 721, a plurality of output ports 722, and an OR723 connected to each of the receiving ports 721.
  • the output port connected to each FTL is also called the output port where the FTL is located, and the receiving port connected to each OR is also called the receiving port where the OR is located.
  • the output port of each FTL 713 is configured to send an optical burst test signal to the OR in the line frame connected to the same all-optical switching unit and selected as the reference frame in the line frame of the embodiment, and receive the reference.
  • the output port of the FTL 713 in the line frame of the present embodiment detected by the receiving port in the reference frame is received by the connected FTL 713 and the optical burst test signal carrying the slot number is received at the OR of the reference frame.
  • the difference between the arrival time on the port and the expected arrival time of the receiving port where the OR of the reference frame is located is the time phase difference.
  • the receiving port of the OR in the reference frame is based on the actual arrival time of the optical burst test signal sent by the output port of the FTL 713 in the line frame of the present embodiment on the receiving port where the OR of the reference frame is located.
  • the time phase difference is obtained by a difference in the expected arrival time phase of the optical burst test signal carrying the same time slot number of the line frame.
  • the receiving port 721 of each OR 723 is configured to receive the optical burst test sent by the output port of the FTL in the other line frame connected to the same all-optical switching unit when the line frame is selected as the reference frame.
  • the signal and according to the optical path difference between the output port of the FTL in the other line frame, the time of receiving the optical burst test signal sent by the output port where the FTL in the line frame is located, and the transmission time carried by the optical burst test signal
  • the slot number is compared with the expected arrival time of the optical burst test signal of the specific slot number expected on the receiving port where the OR of the reference frame is located, and obtains the time phase difference from the output port where the FTL in the other line frame is located ( That is, the difference between the time phase and the expected time phase referenced by the burst port in which the FTL in the other line frame is located is obtained, and the time phase difference is sent to the output port where the FTL in the other line frame is located.
  • the clock phase is such that the time phase referenced by the data output by the output port of the other line frame is in accordance with the design expectations.
  • the circuit frame of this embodiment can be used to perform the flow of the optical burst synchronization method shown in FIG. 5.
  • the specific working principle is not described here. For details, refer to the description of the method embodiment.
  • the output port 712 where the FTL 713 provided in the line frame provided in this embodiment is further between the time phase difference returned by the receiving port where the OR in the reference frame is received in two or more consecutive times according to the preset detection period. Count the local clock and record the counting result, and adjust the clock phase referenced by the power burst data transmission of the output port where the FTL is located according to the two counting results.
  • the all-optical switching unit can be implemented by the AWGR, but is not limited thereto.
  • the optical burst test signal is sent by the FTL to the reference frame, and the receiving port of the reference frame OR is based on the transmission time slot and arrival time of the optical burst test signal. And the optical path difference between the line frame and the reference port of the FTL of the circuit frame, and the time phase difference between the line frame and the reference frame of the embodiment is obtained and fed back to the circuit frame of the embodiment.
  • the FTL of the circuit frame according to this embodiment is based on Time phase difference for time phase adjustment, can be more
  • the optical network switching node of the frame cluster implements the phase alignment between the line frames, so that the optical burst signals with the same time slot number sent by each line frame arrive at the AWGR at the same time, thereby realizing the synchronization of the system. Solved the collision problem caused by out of synchronization.
  • An embodiment of the present invention provides an optical network switching node of a multi-chassis cluster, including a line frame and an all-optical switching unit.
  • the circuit frame of this embodiment is the circuit frame shown in FIG. 6.
  • the working principle of the circuit frame is as shown in FIG. 4 , and the specific structure is shown in FIG. 6 , and details are not described herein again.
  • the all-optical switching unit includes: a plurality of input ends and a plurality of output ends; each output port of each receiving end electrical switching unit is respectively connected to an input end of the all-optical switching unit through the connected FTL Connected, each receiving port of each transmitting end electrical switching unit is connected to an output of the all-optical switching unit via the connected OR.
  • Each receiving end electrical switching unit is configured to receive multiple data units through multiple receiving ports of the receiving end electrical switching unit, perform first-level electrical switching on the received multiple data units, and pass through the receiving end electrical switching unit
  • the FTL connected to multiple output ports is electrically and optically converted and output to the all-optical switching unit.
  • the all-optical switching unit is configured to perform all-optical space-segment exchange on the multi-channel data unit outputted by the receiving-side electrical switching unit, and output the same to the transmitting-end electrical switching unit.
  • a transmitting end electrical switching unit configured to perform photoelectric conversion on the multi-channel data unit output by the all-optical switching unit by an OR connected to the plurality of receiving ports of the transmitting end electrical switching unit, and then perform the first to the multi-channel data unit after the photoelectric conversion After the secondary electrical exchange, the multiple data units are output through the plurality of output ports of the transmitting end electrical switching unit.
  • the all-optical switching unit can be implemented by AWGR.
  • FIG. 1 The specific structure, the connection relationship, and the functions of the related modules of the optical network switching node of the multi-chassis cluster provided in this embodiment are shown in FIG. 1 or FIG. 2, and details are not described herein again.
  • the optical network switching node of the multi-chassis cluster of the embodiment solves the problem of optical burst synchronization based on the circuit frame provided by the foregoing embodiment, realizes the exchange mode of the electric switching-all-optical switching-electrical switching, and implements the OTN-based
  • the multi-frame cluster system increases the capacity of the multi-chassis cluster system and reduces power consumption.
  • Another embodiment of the present invention provides an optical network switching node of a multi-chassis cluster, including a line frame and an all-optical switching unit.
  • the circuit frame of this embodiment is the circuit frame shown in FIG. 7, and the working principle thereof can be seen in FIG.
  • FIG. 7 For a description of the implementation, refer to FIG. 7 for the implementation structure, and details are not described herein again.
  • the all-optical switching unit includes: a plurality of input ends and a plurality of output ends; each output port of each receiving end electrical switching unit is respectively connected to an input end of the all-optical switching unit through the connected FTL Connected, each receiving port of each transmitting end electrical switching unit is connected to an output of the all-optical switching unit via the connected OR.
  • Each receiving end electrical switching unit is configured to receive multiple data units through multiple receiving ports of the receiving end electrical switching unit, perform first-level electrical switching on the received multiple data units, and pass through the receiving end electrical switching unit
  • the FTL connected to multiple output ports is electrically and optically converted and output to the all-optical switching unit.
  • the all-optical switching unit is configured to perform all-optical space-segment exchange on the multi-channel data unit outputted by the receiving-side electrical switching unit, and output the same to the transmitting-end electrical switching unit.
  • a transmitting end electrical switching unit configured to perform photoelectric conversion on the multi-channel data unit output by the all-optical switching unit by an OR connected to the plurality of receiving ports of the transmitting end electrical switching unit, and then perform the first to the multi-channel data unit after the photoelectric conversion After the secondary electrical exchange, the multiple data units are output through the plurality of output ports of the transmitting end electrical switching unit.
  • the all-optical switching unit can be implemented by AWGR.
  • FIG. 1 The specific structure, the connection relationship, and the functions of the related modules of the optical network switching node of the multi-chassis cluster provided in this embodiment are shown in FIG. 1 or FIG. 2, and details are not described herein again.
  • the optical network switching node of the multi-chassis cluster of the embodiment solves the problem of optical burst synchronization based on the circuit frame provided by the foregoing embodiment, realizes the exchange mode of the electric switching-all-optical switching-electrical switching, and implements the OTN-based
  • the multi-frame cluster system increases the capacity of the multi-chassis cluster system and reduces power consumption.

Abstract

本发明实施例提供一种多框集群的光网络交换节点、光突发同步方法及线路框。一种同步方法包括：选择基准框，基准框内的FTL所在的输出端口分别向其他线路框中的OR所在的接收端口发送光突发测试信号，所述光突发测试信号携带有发送时隙编号；每个线路框中的OR所在的接收端口根据其到基准框内的FTL所在的输出端口的光程差、接收光突发测试信号的时间点和发送时隙编号，获取与基准框的时间相位差，根据时间差相位进行本地时钟相位的校准。本发明技术方案解决了光突发同步问题，实现了基于OTN的多框集群系统，增加了系统容量，降低了功耗。

Description

多框集群的光网络交换节点、 光突发同步方法及线路框 技术领域 本发明实施例涉及网络通信技术， 尤其涉及一种多框集群的光网络交换 节点、 光突发同步方法及线路框。 背景技术
随着时间的推移， 第三代（3rd-Generation; 简称为： 3G )移动通信技术、 交互式网络电视（ Internet Protocol Television; 简称为： IPTV ) 、 视频会议、 流媒体、点对点（ Point-to-Point; 简称为： P2P )等网际协议 ( Internet Protocol; 简称为： IP )业务不断的迅速发展， 使得 IP网络流量急剧增长， 互联网带宽 需求呈现了爆炸性的增长。 近几年来， 互联网流量每 12个月增长 1倍， 路由 器的容量每 18个月才增长 1倍。互联网流量的发展远远超过路由器等设备容 量提升的速度。 当前可用的路由器单机和集群中核心路由器的容量已经分别 突破 lTbps和 lOOTbps级别， 尽管还有提高的余地， 但路由器单机和集群节 点的发展受限于高速率端口的光器件成熟度， 并且由于路由器单机和集群节 点电源功耗、 散热、 机房承重等因素， 使得路由器单机和集群节点无法满足 互联网流量的增长需求。
与 IP业务承载网络和节点对应的支撑网络和节点，是并行发展中的传送 网络和传送网节点。 传送网络和节点不仅仅肩负着路由器节点之间的互联传 送承载任务， 还肩负着专线业务。 业务的发展促进了全光交换技术的产生和 发展。 全光交换主要通过采用无源的光器件实现交换， 具备鲜明的低功耗特 征， 业界和研究界针对 IP和类 IP业务的承载网络和节点技术提出了光分组 交换 /光突发交换 ( Optical Packet Switching/ Optical Burst Switching； 简称为： OPS/OBS )等概念， 谋求直接在光信号上的处理、 交换和緩存等。 遗憾的是， 目前 OPS/OBS概念下的很多关键技术、 光随机存储緩存器件、 光报文和光突 发头部直接在光域的处理技术和器件等， 难以获得突破， 无法实际商用。 OPS/OBS概念技术也因为在数据丟失和可靠性方面不能适用于对可靠性要求 比较高的传送应用场景。 目前较为常见的传送网络主要有传统的同步数字体 系（ Synchronous Digital Hierarchy;简称为： SDH )、同步光纤网络（ Synchronous Optical Network; 简称为： SONET ) 和新兴的光传送网 （Optical Transport Network; 简称为： OTN ) 。 新兴 OTN是目前传送网中的主流技术， 将逐步 替代传统的 SDH/SONET。 随业务的发展， 新兴 OTN核心传送节点也面临着 容量需求的问题。 并且与路由器节点相比，新兴 OTN核心传送节点面临的大 容量需求远远超过路由器节点。 一般而言，对 OTN核心传送节点的容量需求 是核心路由器节点的数倍到数十倍。
但是作为 OTN和 OTN核心传送节点的实现， 机拒整机功耗意味着相应 水平的散热需求。 机房允许的热产生密度和功率消耗密度都有限制。 机拒本 身也有允许的热产生密度和功率消耗密度的限制。 早在 2003年， 机拒设计功 耗最大需求已经达到了 10kw, 而当时的机房平均能力设计在 l.lkw每机拒， 实际运行平均功耗在 1.7kw左右； 90%的机房能力设计在 3kw每机拒， 实际 运行平均功耗在 2kw左右； 最高设计为 6kw每机拒， 而当时的最高功耗机拒 已经达到了 12kw。 目前而言， 2200mm ( H ) x 600mm ( W ) x 600mm ( D ) 的标准电信设备的机拒， 机拒整机功耗可以达到 20〜24kw左右， 已经远高于 目前标准机拒布局的机房 4〜6kw每机拒的临界极限散热能力， 相当于机房 的 4〜5 个标准机拒功率和散热预算。另夕卜，受限于高速电背板的信号衰减大， 单个设备只能有 75cm〜100cm的传输距离， 为了克服传输距离问题， 这样的 机拒中往往布放两个设备 (框）， 就算布放两个设备 (框)的机拒整机容量也才在 12.8T左右（其中，典型的每个设备的容量在 6.4T左右）。 目前， 小于 OTU-k 线路带宽 (2.5G;10G;40G;100G)的子波长带宽颗粒的交换依赖于 OTN电节点， OTN电节点的容量需求也已经达到了一个 P到数个 P的 P级别要求， 面对 P 级别的容量需求， 传统的 OTN电节点也受整机电源功耗、散热、 机房承重等 因素的制约，难以实现突破的尴尬场景， 于是多框集群成为了 OTN未来发展 的方向。对于 OTN电节点来说，要实现多框级联只能采用光或电互连和全电 交换， 全电交换的功耗较大， 限制了多设备级联能力的发挥。 为了解决全电 交换的功耗较大的问题， 可以使用全光交换代替全电交换， 但是对于全光交 换来说光突发同步是实现全光交换的关键。 发明内容 本发明提供一种多框集群的光网络交换节点、光突发同步方法及线路框， 用以解决光突发同步的问题， 以实现基于 OTN技术的多框集群系统、增加系 统容量， 满足日益增长的带宽需求， 进而解决现有技术电交换节点因功耗较 大限制多框集群实现的问题。
本发明一方面提供一种光突发同步方法， 包括：
从与同一个全光交换单元连接的多个线路框中选择一个线路框作为基 准框， 所述基准框内的波长可调光发送激光器 FTL 所在的输出端口通过所 述 FTL 分别向与所述同一个全光交换单元连接的多个线路框中的光接收模 块 OR所在的接收端口发送光突发测试信号， 所述光突发测试信号携带有发 送时隙编号；
与所述同一个全光交换单元连接的每个线路框中的 OR所在的接收端口 根据其到所述基准框内的 FTL所在的输出端口的光程差、 接收所述光突发测 试信号的时间点和所述光突发测试信号中携带的发送时隙编号 , 获取与所述 基准框内的 FTL所在的输出端口的时间相位差， 并根据所述时间差相位调整 所述 OR所在的接收端口上的电突发数据接收所参考的时钟相位和与所述 OR 对应的位于同一线路框内的 FTL所在的输出端口上的电突发数据发送所参考 的时钟 目位。
本发明另一方面提供一种光突发同步方法， 包括：
从与同一个全光交换单元连接的多个线路框中选择一个线路框作为基 准框；
与所述同一个全光交换单元连接的每个所述线路框中的波长可调光发 送激光器 FTL所在的输出端口通过所述 FTL分别向所述基准框内的光接收 模块 OR所在的接收端口发送光突发测试信号， 所述光突发测试信号携带有 发送时隙编号；
所述基准框内的 OR所在的接收端口根据其与每个线路框中的 FTL所在 的输出端口的光程差、 接收到每个线路框的 FTL所在的输出端口发送的光突 发测试信号的时间和所述光突发测试信号携带的发送时隙编号 , 获取所述基 准框内的 OR所在的接收端口与每个线路框内的 FTL所在的输出端口的时间 相位差， 并将与每个线路框的 FTL所在的输出端口的时间相位差分别发送给 每个线路框的 FTL所在的输出端口； 每个线路框的 FTL所在的输出端口分别根据所述时间相位差， 调整所述 FTL所在的输出端口上的电突发数据发送所参考的时钟相位。
本发明一方面提供一种线路框， 包括：
接收端电交换单元和发送端电交换单元； 所述接收端电交换单元包括多 个接收端口、 多个输出端口和每个输出端口所连接的波长可调光发送激光器 FTL; 所述发送端电交换单元包括多个接收端口、 多个输出端口和每个接收 端口所连接的光接收模块 OR;
每个所述 FTL所在的输出端口， 用于在所述线路框被选为基准框时， 向 与所述基准线路框连接于同一个全光交换单元的其他线路框中的光接收模 块 OR所在的接收端口发送光突发测试信号， 以使其他线路框中的 OR所在 的接收端口根据其与所述基准框内发送所述基准测试信号的 FTL所在的输出 端口的光程差、 接收所述光突发测试信号的时间和所述光突发测试信号携带 的发送时隙编号，获取与所述基准框内的 FTL所在的输出端口的时间相位差， 并根据所述时间相位差调整所述 OR所在接收端口上的电突发数据接收所参 考的时钟相位和与所述 OR对应的位于同一线路框内的 FTL所在的输出端口 上的电突发数据发送所参考的时钟相位；
每个所述 OR所在的接收端口， 用于在与所述线路框连接于同一个全光 交换单元的其他线路框中的一个线路框被选为基准框时， 接收由所述基准框 内的 FTL所在的输出端口通过所述 FTL发送的光突发测试信号，并根据其到 所述基准框内发送所述光突发测试新信号的 FLT所在的输出端口的光程差、 接收所述光突发测试信号的时间和所述光突发测试信号携带的发送时隙编 号， 获取与所述基准框内发送所述光突发测试信号的 FTL所在的输出端口的 时间相位差， 并根据所述时间相位差调整所述 OR所在的接收端口上的电突 发数据接收所参考的时钟相位和与 OR对应的位于同一线路框内的 FTL所在 的输出端口上的电突发数据发送所参考的时钟相位。
本发明另一方面提供一种线路框， 包括：
接收端电交换单元和发送端电交换单元； 所述接收端点交换单元包括多 个接收端口、 多个输出端口和每个输出端口所连接的波长可调光发送激光器 FTL; 所述发送端电交换单元包括多个接收端口、 多个输出端口和每个接收 端口所连接的光接收模块 OR; 每个所述 FLT所在的输出端口， 用于从所在线路框向与所述线路框连接 于同一个全光交换单元且被选择为基准框的基准框内的 OR 所在的接收端 口发送光突发测试信号， 并接收所述基准框内的 OR所在的接收端口发送的 所述线路框的 FTL所在的输出端口与所述基准框内的 OR所在的接收端口的 时间相位差， 并根据所述时间相位差调整所述 FTL所在的输出端口上的电突 发数据发送所参考的时钟相位； 所述光突发测试信号携带有发送时隙编号； 所述时间相位差是由所述基准框内的 OR所在的接收端口根据其与所述线路 框内发送所述光突发测试信号的 FTL所在的输出端口的光程差、 接收到所述 线路框的 FTL所在的输出端口发送的光突发测试信号的时间和所述光突发测 试信号携带的发送时隙编号获取的；
每个 OR所在的接收端口， 用于在所述线路框被选为基准框时， 接收与 所述基准线路框连接于同一个全光交换单元的其他线路框内的 FTL 所在的 输出端口发送的光突发测试信号， 并根据其与其他线路框内的 FTL所在的输 出端口的光程差、 接收到其他线路框的 FTL所在的输出端口发送的光突发测 试信号的时间和所述光突发测试信号中的发送时隙编号， 获取与其他线路框 内的 FTL所在的输出端口的时间相位差， 并将所述时间相位差发送给其他线 路框内的 FTL所在的输出端口，以使其他线路框内的 FTL所在的输出端口根 据所述时间相位差调整其上的电突发数据发送所参考的时钟相位。
本发明一方面提供一种多框集群的光网络交换节点， 包括本发明一方面 提供的任一线路框和全光交换单元；
所述全光交换单元包括： 多个输入端和多个输出端； 每个所述接收端 电交换单元的每个输出端口通过所连接的 FTL 分别与所述全光交换单元 的一个输入端相连接， 每个所述发送端电交换单元的每个接收端口通过所 连接的 OR分别与所述全光交换单元的一个输出端相连接；
每个所述接收端电交换单元， 用于通过所述接收端电交换单元的多个 接收端口接收多路数据单元， 对接收到的多路数据单元进行第一级电交 换，并通过所述接收端电交换单元的多个输出端口所连接的 FTL进行电光 转换后输出给所述全光交换单元；
所述全光交换单元， 用于对所述接收端电交换单元输出的多路数据单 元进行全光空分交换后输出给所述发送端电交换单元； 所述发送端电交换单元， 用于通过所述发送端电交换单元的多个接收 端口所连接的 OR对所述全光交换单元输出的多路数据单元进行光电转 换， 然后对光电转换后的多路数据单元进行第二级电交换后通过所述发送 端电交换单元的多个输出端口输出多路数据单元。
本发明另一方面提供一种多框集群的光网络交换节点，包括本发明另一 方面提供的任一线路框和全光交换单元；
所述全光交换单元包括： 多个输入端和多个输出端； 每个所述接收端 电交换单元的每个输出端口通过所连接的 FTL 分别与所述全光交换单元 的一个输入端相连接， 每个所述发送端电交换单元的每个接收端口通过所 连接的 OR分别与所述全光交换单元的一个输出端相连接；
每个所述接收端电交换单元， 用于通过所述接收端电交换单元的多个 接收端口接收多路数据单元， 对接收到的多路数据单元进行第一级电交 换，并通过所述接收端电交换单元的多个输出端口所连接的 FTL进行电光 转换后输出给所述全光交换单元；
所述全光交换单元， 用于对所述接收端电交换单元输出的多路数据单 元进行全光空分交换后输出给所述发送端电交换单元；
所述发送端电交换单元， 用于通过所述发送端电交换单元的多个接收 端口所连接的 OR对所述全光交换单元输出的多路数据单元进行光电转 换， 然后对光电转换后的多路数据单元进行第二级电交换后通过所述发送 端电交换单元的多个输出端口输出多路数据单元。
本发明一方面提供的光突发同步方法、 线路框及多框集群的光网络交换 节点， 从连接于同一个全光交换单元的多个线路框中选择一个线路框作为基 准框， 并由基准框向其他线路框发送携带发送时隙的光突发测试信号， 而其 他线路框根据各自与基准框之间的光程差、 接收光测试信号的本地时间以及 光测试信号中携带的基准框侧的发送时隙获取各自与基准框的时间相位差， 进而基于时间相位差进行本地时钟相位的校准， 使得各个线路框发送的携带 相同时隙编号的光突发信号能够同时到达全光交换单元，实现了光突发同步， 进而实现了采用电交换-全光空分交换-电交换的交换方式，充分利用全光空分 交换的低功耗特点， 实现了基于 OTN技术的多框集群系统， 通过多框集群增 大了 OTN核心节点的容量，提高了传送网的带宽利用率， 解决了现有技术中 OTN电节点受整机电源功耗、 散热、 机房承重等因素的制约， 难以实现扩容 的问题。
本发明另一方面提供的光突发同步方法、 线路框及多框集群的光网络交 换节点， 从连接于同一个全光交换单元的多个线路框中选择一个线路框作为 基准框， 其他线路框分别向基准框发送携带发送时隙的光突发测试信号， 由 基准框根据与其他线路框、 接收到光突发测试信号的时间以及光突发测试信 号携带的发送时隙获取与其他线路框的时间相位差， 并将获取的时间相位差 反馈给其他线路框，使其他线路框根据时间相位差进行本地时钟相位的校准， 使得各个线路框发送的携带相同时隙编号的光突发信号能够同时到达全光交 换单元， 实现了光突发同步，进而实现了采用电交换 -全光空分交换-电交换的 交换方式， 充分利用全光空分交换的低功耗特点， 实现了基于 OTN技术的多 框集群系统， 通过多框集群增大了 OTN核心节点的容量，提高了传送网的带 宽利用率， 解决了现有技术中 OTN电节点受整机电源功耗、 散热、 机房承重 等因素的制约， 难以实现扩容的问题。 附图说明 为了更清楚地说明本发明实施例或现有技术中的技术方案， 下面将对实 施例或现有技术描述中所需要使用的附图作一简单地介绍， 显而易见地， 下 面描述中的附图是本发明的一些实施例， 对于本领域普通技术人员来讲， 在 不付出创造性劳动的前提下， 还可以根据这些附图获得其他的附图。
图 1为本发明一实施例提供的多框集群的光网络交换节点的结构示意图； 图 2为本发明另一实施例提供的多框集群的光网络交换节点的结构示 意图；
图 3为本发明一实施例提供的多框集群的光网络交换节点中的部分结 构示意图；
图 4为本发明一实施例提供的光突发同步方法的流程图；
图 5为本发明另一实施例提供的光突发同步方法的流程图；
图 6为本发明一实施例提供的用于实现本发明实施例提供的光突发同 步方法的线路框的结构示意图；
图 7为本发明另一实施例提供的用于实现本发明实施例提供的光突发 同步方法的线路框的结构示意图。 具体实施方式 为使本发明实施例的目的、 技术方案和优点更加清楚， 下面将结合本 发明实施例中的附图， 对本发明实施例中的技术方案进行清楚、 完整地描 述， 显然， 所描述的实施例是本发明一部分实施例， 而不是全部的实施例。 基于本发明中的实施例， 本领域普通技术人员在没有作出创造性劳动前提 下所获得的所有其他实施例， 都属于本发明保护的范围。
图 1为本发明一实施例提供的多框集群的光网络交换节点的结构示意 图。 如图 1所示， 本实施例的光网络交换节点包括： 至少一个接收端电交 换单元 11、 至少一个全光交换单元 12和至少一个发送端电交换单元 13。 其中， 相互对应的接收端电交换单元 11和发送端电交换单元 13位于一个 线路框内。
其中，每个接收端电交换单元 11包括多个接收端口 111、 多个输出端 口 112和每个输出端口 112所连接的快速波长可调激光器 （Fast Tunable Laser; 简称为： FTL ) 113; 每个接收端电交换单元 11具有相同数量的接 收端口 111、 输出端口 112和 FTL113 , 且每个接收端电交换单元 11的接 收端口 111和输出端口 112之间具有对应关系。每个发送端电交换单元 13 包括多个接收端口 131、 多个输出端口 132和每个接收端口 131所连接的 光接收模块（ Optical Receiver; 简称为： OR ) 133; 每个发送端电交换单 元 13具有相同数量的接收端口 131、 输出端口 132和 OR133 , 且每个发 送端电交换单元 13的接收端口 131和输出端口 132之间具有对应关系。 在图 1中示出每个接收端电交换单元 11包括 4个接收端口 111、 4个输出 端口 112和每个输出端口 112所连接的 FTL113 , 4个接收端口 111分别为： 第一接收端口、 第二接收端口、 第三接收端口和第四接收端口， 4个输出 端口 112分别包括： 第一输出端口、 第二输出端口、 第三输出端口和第四 输出端口。 每个发送端电交换单元 13包括 4个接收端口 131、 4个输出端 口 132和每个接收端口 131连接的 OR133; 4个接收端口 131也分别为第 一接收端口、 第二接收端口、 第三接收端口和第四接收端口， 4个输出端 口 132分别为第一输出端口、 第二输出端口、 第三输出端口和第四输出端 口。 其中， 所有第一接收端口对应的编号相同， 为 1 ; 所有第二接收端口 对应的编号相同， 为 2; 所有第三接收端口对应的编号相同， 为 3 , 所有 第四接收端口对应的编号相同， 为 4。 同理， 所有第一输出端口、 所有第 二输出端口、 所有第三输出端口和所有第四输出端口分别对应的编号也相 同， 分别为 1、 2、 3和 4。
其中， 接收端电交换单元 11的接收端口 111和输出端口 112之间还 包括其他电路， 发送端电交换单元 12的接收端口 131和输出端口 132之 间同样包括其他电路， 在图 1中均用一 "矩形框" 表示。
每个全光交换单元 12包括多个输入端 12a和多个输出端 12b。 其中， 输入端 12a与输出端 12b的数量相同， 并具有对应关系。
每个接收端电交换单元 11 的每个输出端口 112 分别通过所连接的 FTL113与一个全光交换单元 12的一个输入端 12a相连接； 每个发送端电 交换单元 13的每个接收端口 131分别通过所连接的 OR1313与一个全光 交换单元 12的一个输出端 12b相连接。
每个接收端电交换单元 11 ,用于通过其多个接收端口 111接收多路数 据单元， 对接收到的多路数据单元进行第一级电交换， 并通过其多个输出 端口 112所连接的 FTL113进行电光转换后输出给全光交换单元 12。 全光 交换单元 12, 用于通过其输入端 12a接收接收端电交换单元 11输出的经 电光转换的多路数据单元， 并对接收到的经电光转换后的多路数据单元进 行全光空分交换， 然后通过其输出端 12b输出给发送端电交换单元 13。发 送端电交换单元 13 ,用于通过其多个接收端口 131和接收端口 131所连接 的 OR133接收全光交换单元 12输出的多路数据单元并对全光交换单元 12 输出的多路数据单元进行光电转换， 然后对经光电转换后的多路数据单元 进行第二级电交换后通过其多个输出端口 132输出多路数据单元。
本实施例的多框集群的光网络交换节点，通过采用电交换-全光空分交 换-电交换的交换方式， 充分利用全光空分交换的低功耗特点， 实现了基于 OTN技术的多框集群系统， 通过多框集群增大了 OTN核心节点的容量， 提高了传送网的带宽利用率， 解决了现有技术中 OTN 电节点受整机电源 功耗、 散热、 机房承重等因素的制约， 难以实现扩容的问题。
图 2为本发明另一实施例提供的多框集群的光网络交换节点的结构示 意图。 本实施例基于图 1所示实施例实现， 如图 2所示， 本实施例的全光 交换单元 12为 AWGR。 具体的， 每个接收端交换单元 11 的输出端口 112 通过所连接的 FTL113分别与一个 AWGR12的一个输入端相连接， 每个发送端电交换单 元 13的接收端口 131通过所连接的 OR133分别与一个 AWGR12的一个 输出端相连接。 其中， 所有接收端电交换单元 11 的相同编号的输出端口 112分别通过所连接的 FTL113连接于同一个 AWGR12的不同输入端。 如 图 2所示，所有接收端电交换单元 11的第一输出端口均通过所连接的 FTL 与第一个 AWGR12的不同输入端相连接， 所有接收端电交换单元 11的第 二输出端口均通过所连接的 FTL与第二个 AWGR12的不同输入端相连接， 等等。 其中， 所有发送端电交换单元 13的相同编号的接收端口 131分别 通过所连接的 OR133与同一个 AWGR12的不同输出端连接， 并且连接该 AWGR12的不同输入端的所有接收端电交换单元 11的相同编号的输出端 口 112的编号与连接该 AWGR12的不同输出端的所有发送端电交换单元 13的相同编号的接收端口 131的编号相同。 如图 2所示， 所有发送端电交 换单元 13的第一接收端口通过所连接的 OR分别与第一个 AWGR12的不 同输出端相连接， 所有发送端电交换单元 13 的第二接收端口通过所连接 的 OR分别与第二个 AWGR12的不同输出端相连接， 等等。
在本实施例中， 连接 FTL113的接收端电交换单元 11的输出端口 112 (简称为 FTL113所在的输出端口 112 ) 主要负责电突发信号的生成、 参 考时钟时刻指示加以发送、 对 FTL113的电光转换 FTL波长的电控制等。 连接 OR133的发送端电交换单元 13的接收端口 131 (简称为 OR133所在 的接收端口 131 ) 主要负责光波信号到电信号的转换等。 其中， FTL113 通过光纤与 AWGR12连接， AWGR12通过光纤与 OR133连接， 于是来自 于 FTL113的上行光波信号经过上行光纤被发送到 AWGR12,从 AWGR12 输出的下行光波信号经过下行光纤被发送到 OR133。 在具体实施中， 接收 端电交换单元 11 的每个接收端口 111接收多路数据单元， 对接收到的多 路数据单元进行第一级电交换后， 由每个输出端口 112 输出给所连接的 FTL113 , 由 FTL113对经过第一级电交换后的电时分突发数据单元进行电 光转换， 形成时分光突发信号， 并将时分光突发信号发送给全光交换单元 12, 即 AWGR12。 每个 AWGR12, 用于将相同时隙上来自不同 FTL113 的时分光突发信号交换到不同的输出端发送给不同的发送端电交换单元 13。 发送端电交换单元 13先由其 OR133接收 AWGR12发送的时分光突 发信号， 并将时分光突发信号转换为一路电时分突发数据单元， 然后发送 给与 OR133所连接的接收端口 131 , 然后进行第二级电交换， 最后通过其 相应输出端口 132输出电时分突发数据单元， 从而使电时分突发数据单元 离开集群节点。
在实际应用过程中， 本实施例的光网络交换节点在逻辑上可以与查尔 斯三级网络相对应。 例如， 部分接收端电交换单元 11 (除 FTL之外的部 分）可以为查尔斯三级网络（即三级 CLOS交换网络）的第一级（ Stage 1 ; 简称为： S 1 ) , 部分发送端电交换单元 13 (除 OR之外的部分）可以为三 级 CLOS交换网络的第三级（Stage 3 ; 简称为： S3 ) ; 而中间的全光交换 单元 12并结合接收端电交换单元 11中的 FTL和发送端电交换单元 13中 的 OR可以为三级 CLOS交换网络的第二级（ Stage 2; 简称为： S2 ) 。 其 中， 在本实施例中的电时分突发数据单元可以为 ODU-k信号， S1 和 S3 可以实现 ODU-k信号的电域交换， k可以取 0到 4的中任意整数值。例如： S 1和 S3的接收端口 （即接收端电交换单元 1 1的接收端口 11 1和发送端 电交换单元 13的接收端口 131 )可以传输 ODU-2或 OTU-2信号， 也可以 传输 ODU-3或 OTU-3信号。 并且当每个 S1和每个 S3包括 4个接收端口 时， 4个接收端口均可以传输 ODU-2或 OTU-2信号， 或者 4个接收端口 中有 1个传输 ODU-3或 OTU-3信号， 其他传输 ODU-2或 OTU-2信号。 在具体实施过程中， S1可以将 ODU-k信号中的低一级信号数据单元， 最 小到 ODU-0解复用出来， 并进行无阻塞的全交换。 完成 S 1的交换后， 各 个 ODU-k信号被 S2中的 FTL所在的输出端口完成突发封装， 由 S2中的 FTL发送到 AWGR, 进行 S2上的全光交换。 相应的， S2中的 OR所在的 接收端口完成突发封装的 ODU-k信号的解封装， ODU-k无阻塞全交换， 并封装到高阶 ODU-k/OTU-k中通过标准的 OTN接口， 离开集群节点。
其中， AWGR是全光交换系统中常用的、 核心的无源光交换器件。 AWGR的主要特性是某波长的光突发信号从其某输入端输入时，从哪个输 出端输出， 取决于光突发信号本身的波长； 例如： 从 AWGR的第 1输入 端输入的不同波长的光突发信号， 将从 AWGR的不同输出端输出； 并且 输出到同一输出端的光突发信号的波长也不相同。 对一 4x4的多重复周期 ( n+1 )的 AWGR, 其中 n>=0, 其对不同波长的光突发信号的空分交换特 性如表 1所示。
表 1
Figure imgf000014_0001
其中， 以第 1输入端和第 1输出端为例， 对表 1的意思进行说明。 即 由第 1 输入端输入的波长分别为 λ1 λ5 λ4η+1 的光突发信号分 别在第 1输出端输出， 对于其他输入端和输出端可类比第 1输入端和第 1 输出端的关系。 另外， 从横向看表 1 , 即分析第 1输出端-第 4输出端分别 输出的光突发信号的波长可见， 每个输出端输出的光突发信号的波长均不 同。
其中， AWGR被广泛用于光波复用（ Wavelength Division Multiplexing; 简称为： WDM ) 或密集型光波复用 （ Dense Wavelength Division Multiplexing; 简称为： DWDM ) 网络， 用于实现波长级别的交换， 对应 的交换带宽颗粒往往为 lOGbps, 40Gbps, lOOGbps 的大颗粒带宽， 本实 施例通过将 AWGR应用于多框集群系统中， 作为多框集群系统的全光交 换单元， 实现电交换-全光空分交换 -电交换的三级交换模式， 充分利用了 AWGR具有大带宽颗粒的优势， 实现了全光交换的多框集群系统。 另外， 由于 AWGR是采用无源的光器件实现交换的， 其功耗非常低， 与电交换 节点不同， AWGR不再受其功耗、 散热等因素的限制， 与电交换节点相比 其灵活性更强， 进一步保证了多框集群系统的发展， 为满足互联网逐渐增 长的流量需求打下了基础。
在实际实现过程中， 上述实施例提供的多框集群的传送网系统中的一 个接收端电交换单元 11和一个发送端电交换单元 13作为电交换单元（线 路框） 的上行和下行部分， 构成完整意义的电交换节点单元， 通常被部署 在一个线路框内， 在逻辑上来看， Sl、 与 S1连接的 FTL、 S3和与 S3连 接的 ROSA部署在线路框内； 而全光交换单元 12中的 AWGR12通常被部 署在集中交叉框。 其中， AWGR12与 FTL121之间的交叉连接由 FTL113 输出的光突发信号的波长决定， 也就是说全光交换单元 12 中的交叉连接 控制实际上是对 FTL转换成不同波长的光突发信号的波长配置控制过程。 其中， 对于有 200个线路框的传送网集群系统而言， 每个 AWGR就要接 收到 200个 FTL发送的光突发信号， 如果各路光突发信号到达 AWGR的 时刻与 AWGR的本地时间不匹配， 则就会造成 AWGR完成空分交换后的 光突发信号之间发生重叠碰撞（也即相同波长的不同突发信号重叠在一起 同时到达 OR, OR因此不能正确接收和处理这些信号）， 导致发送端电交 换单元不能实现时分接收， 导致系统传输失败， 或者需要在接收端电交换 单元之前部署多接收机，进行波分接收，这又会增加系统的复杂度和成本。
基于上述可见， 对多框集群的光网络交换节点而言， 各光突发信号之 间的同步问题是本发明实施例提供的多框集群的光网络交换节点所面临 的重要问题。 其中， 光突发信号的同步被称为光突发同步。 下面以图 3所 示的多框集群的光网络交换节点中的部分结构进行 ODU-2 中包含最小颗 粒 ODU-0的全光交换为例， 对光突发同步进行说明。
首先， 假设 FTL发送到光纤线路（简称为光路）上的光突发数据单元 是以 3为周期的， 即每个突发数据包封装有 1个 ODU-0的数据流。 每 3 个连续的光突发组成一个帧， 每个光突发对应一个时隙， 即一个帧包含 3 个时隙。 其中， 若 n个帧组成一个复帧， 则一个复帧包含 3xn个时隙， 可 以承载 3xn个光突发信号。
在图 3中仅示出 4个线路框， 分别为线路框 1、 2、 3和 4。 其中， 每 个线路框分别包括 Sl、 S3、 FTL和 OR, 在图 3中仅示出每个线路框中编 号为 1的一个 FTL和一个 OR,分别为 FTL1— 1、 FTL2— 1、 FTL3— 1、 FTL4 1 和 0R1— 1、 0R2— 1、 0R3— 1、 0R4— 1。 FTL1— 1、 FTL2— 1、 FTL3— 1、 FTL4 1 依次与 AWGR 的输入端连接， OR1— 1、 OR2— 1、 OR3— 1、 OR4 1 依次与 AWGR的输出端连接。
对于各个 FTL在同一复帧的同一帧的同一时隙发送的光突发信号，要 求同时到达 AWGR, 如果各个 FTL在同一复帧的同一帧的同一时隙发送 的光突发信号未同时到达 AWGR, 则说明光突发不同步， 反之， 说明光突 发同步。 为便于描述光突发同步， 需要定义一个基准时间。 其中， 可以以 任何一个 FTL或 AWGR作为基准点， 而将基准点的本地时间作为基准时 间， 其他 FTL或 AWGR向该基准时间看齐。 当选定基准点后， 将以基准 点的某一本地时间点为基准， 由基准点发送的携带基准点时间的对应时隙 编号指示了特定基准时间相位的光突发信号到达一地点 A 时信号携带的 时隙编号对应的基准点处的本地时间记为地点 A 的参考基准时间的本地 时间（或者由地点 A发送的携带特定时隙编号的特定相位的光突发信号到 达基准点时， 时隙编号和到达时刻与基准点的时间一致的时候， A点发送 该信号的时刻时 A点的本地时间为地点 A参考基准时间的本地时间） ， 也就是参考基准时间的光突发信号的光程上的地点 A的到达时间为地点 A 以基准时间为参考的本地时间 （该本地时间与基准点上的基准时间之差， 等于光信号走完基准点到 A点所需要花费的时间 ) 。
为便于描述， 本示例以 AWGR的本地时间为基准时间。 如图 3所示， 若线路框 1、 2、 3和 4与 AWGR之间的上行光程和下行光程均一定， 光 突发信号的传输速度也一定， 则在某时刻上， 线路框 1、 2、 3和 4的 S1 和 S3在 AWGR的本地时间与 AWGR的基准时间（即 AWGR的本地时间 ) 之间一致，则各线路框的 FTL所在输出端口参考各自的本地时间发送光突 发信号在 AWGR的本地时间的同一时刻到达， 满足系统的突发信号同步 要求。
例如：假设 FTL1— 1与 AWGR之间的上行时差为 6.3个光时隙 , FTL2— 1 与 AWGR之间的上行时差为 7个光时隙， FTL3— 1与 AWGR之间的上行 时差为 5.7个光时隙， FTL4— 1与 AWGR之间的上行时差为 7.4个光时隙。 同时， 4叚设各 FTL的波长配置如表 2所示。 表 2
Figure imgf000017_0001
由表 2可知， FTLl— 1分别配置了如下波长和连接关系： （ 1 )线路框 1经过 FTLl— 1连接到 AWGR的第 1输入端到 AWGR的第 3输出端 （即 OR3— 1 ) 到线路框 3建立了一个基于第 1时隙的子波长连接， 以及线路框 3到线路框 1的一个反向连接。 （ 2 )线路框 1经过 FTLl 1连接到 AWGR 的第 1输入端到 AWGR的第 2输出端 （ OR2— 1 ) 到线路框 2建立了一个 基于第 2时隙的子波长连接； 以及线路框 2到线路框 1的一个反向连接。 ( 3 )线路框 1经过 FTL1— 1连接到 AWGR的第 1输入端到 AWGR的第 4 输出端 （OR4— 1 ) 到线路框 4建立了一个基于第 3时隙的子波长连接； 以 及线路框 4到线路框 1的一个反向连接。 关于其他 FTL与此类似， 其中空 闲表示在该时隙上未进行连接建立。
基于上述，为了实现突发同步，各 FTL发送突发信号的时间关系如下： 假设某一时刻， 距离 AWGR存在 6.3光时隙的光路程的 FTL1— 1正在发送 第 （N+1 ) 复帧的第 2帧的第 1 时隙的光突发信号； 则距离 AWGR存在 7.0光时隙的光路程的 FTL2— 1， 第 （ N+1 ) 复帧的第 2帧的第 1时隙的光 突发信号已经发送完， 正在准备下一时隙的光突发信号的发送； 距离 AWGR存在 5.7光时隙的光路程的 FTL3— 1正在发送第（N+1 )复帧的第 1 帧的第 3 时隙的光突发信号； 距离 AWGR存在 7.4 光时隙的光路程的 FTL4— 1正在发送第 （（N+1)复帧的第 2帧的第 2时隙的光突发信号。 由上 述可见， 各个 FTL到 AWGR的光路程的光传输延迟， 与各个 FTL本地时 间形成了合理的补偿匹配， 在 AWGR处， 此时来自各 FTL的第 N复帧的 倒数第二帧的第 3时隙已经穿越了 AWGR, 来自各 FTL的第 N复帧的最 后一帧的第 1时隙的光突发信号即将到来。
在本发明各实施例中， 如果 FTL1— 1在 AWGR的本地时间 , FTL2— 1在 AWGR的本地时间 , FTL3— 1在 AWGR的本地时间和 FTL4— 1在 AWGR的本地 时间， 四个在 AWGR的本地时间相同， 则称实现了光突发同步。
基于上述同步的实现， 在 AWGR上完成了空分交换的光突发信号， 即使 经过了不同的光路程， 在各个 OR的本地时间也是同步的， 不存在突发信号的 重叠碰撞问题。
对于全光交换的光突发同步问题， 现有技术也存在几种解决方案。 例 如： 使用集中统一时间和时钟分发， 实现各框光突发信号的同步。 但这要 求使用的时间分发系统与各个 FTL/OR到 AWGR的光程相匹配， 存在工 程上的困难。 通常只适用于小型的单框节点设备， 对于多框节点场景， 框 与框之间的分发延迟和信号传输延迟都是随机分布的， 统一时钟和相位的 实现相对较为困难。 或者在光突发信号到达的交换设备（AWGR ) 的前端 增加光延迟线实现的緩存设备， 对齐后再进行光交换， 并在统一的严格同 步后的下一时隙发送出去。其中光緩冲存储器件还不成熟，而且价格昂贵， 采用光纤为基本的延迟器件的光緩存的緩存能力有限， 体积庞大且成本 高， 尤其不适用于多框集群系统中。 又例如： 现有技术中还存在用电存储 器緩存替换光延迟线緩存的方案， 但该方案需要先进行光电转换， 再进行 电存储， 然后再经过电光转换才能输出到下一级， 其处理相对复杂、 成本 昂贵、 且功耗较大， 对于对功耗相对敏感的多框集群系统也不适用。 多框集群系统， 故本发明以下实施例为基于 FTL和 AWGR实现的大容量 的多框集群的光网络交换节点的光突发同步提供了解决方案。
图 4为本发明一实施例提供的光突发同步方法的流程图。如图 4所示， 本实施例的光突发同步方法包括：
步骤 401、 从与同一个全光交换单元连接的多个线路框中选择一个线 路框作为基准框。
在本实施例中， 以全光交换单元为 AWGR为例。
本实施例所述的同步是指在各框经 FTL发送到同一个 AWGR的所有 携带相同时隙编号的光突发信号同时到达该 AWGR,故本实施例针对每个 AWGR进行说明。 如图 3所示， 有 4个线路框与同一个 AWGR连接。 本 实施例可以从中选择任意一个线路框作为基准框。
步骤 402、基准框内的 FTL所在的输出端口分别向与同一个全光交换 单元连接的多个线路框中的 OR所在的接收端口发送光突发测试信号， 所 述光突发测试信号携带有发送时隙编号。
在本实施例中， 与同一个 AWGR连接的相对应的 FTL和 OR位于同 一线路框内， 如图 3所示。 其中， 基准框内的 FTL所在地输出端口可以不 同的突发开销时隙逐一向与同一个 AWGR连接的多个线路框 （包括基准 框在内）发送光突发测试信号； 每个线路框内的 OR所在的接收端口在不 同突发开销时隙上接收上述光突发测试信号。
在本实施例中， 以基准框的时间为基准， 所有线路框均向基准框的时 间对齐。 为了便于各线路框中的 OR向基准框对齐， 基准框中的 FTL所在 的输出端口在发送的光突发测试信号中携带发送该光突发测试信号的发 送时隙编号。 由于整个系统中， 各种光突发信号的发送都是以突发时隙为 基准的， 故本实施例直接携带发送时隙编号来表征光突发测试信号是在基 准框的 FTL所在输出端口的哪个时间点发送的。
步骤 403、 与同一个全光交换单元连接的每个线路框中的 OR所在的 接收端口根据其到基准框内的 FTL所在的输出端口的光程差、接收到光突 发测试信号的时间点和光突发测试信号中携带的发送时隙编号， 获取 OR 所在的接收端口上的电突发信号接收所参考的本地时间相位与从基准框 经 FTL发送过来的光突发开销突发信号指示的基准时间相位之差（即时间 相位差） ， 并根据该时间相位差调整 OR所在的接收端口上电突发数据接 收所参考的时钟相位，并根据 OR到对应的位于同一线路框内的 FTL的光 程差调整 OR对应的位于同一线路框内的 FTL所在输出端口上的电突发数 据发送所参考的时钟相位。 简单的说， 就是 OR所在的接收端口将其本地 时钟的时间对准到携带基准时隙编号的基准突发信号的到达时刻所指示 的时间上 ,并相应的也校正 FTL所在发送端口上的突发数据发送所参考的 时钟到正确的时间。
与同一 AWGR连接的每个线路框中的 OR 所在的接收端口接收到光 突发测试信号时， 记录接收光突发测试信号的时间， 即 OR所在的接收端 口接收电突发数据所参考的本地时钟所对应的光突发测试信号到达该 OR 的时刻。 该到达时刻具体由 OR接收所参考的时钟的计数器的数值（时隙 /脉冲 ) 来表征的。
在本实施例中， 与同一 AWGR连接的每个线路框中的 OR所在的接 收端口已经预先获取其与所在相同线路框中的对应的 FTL 所在的输出端 口之间的光程差， 该光程差具体为光突发测试信号从与该 OR同一线路框 的对应的 FTL所在的输出端口经过 AWGR将光突发测试信号传输到该 OR 所在的接收端口所需要的传输时间， 通常该光程差是固定的。
基于上述， 每个线路框的 OR所在的接收端口根据光突发测试信号的 到达时刻、 OR所在的接收端口与该 OR对应的同一线路框的 FTL所在的 输出端口之间的光程差和光突发测试信号中携带的发送时隙编号， 获得与 各个线路框的 FTL 所在的输出端口发送电突发数据所参考的本地时钟时 间与设计期望的本地时钟时间之间的时间相位差， 也就是时间差， 并将各 线路框的 FTL 所在的输出端口发送电突发数据所参考的本地时钟时间校 正到设计期望的本地时钟时间。则这个 FTL所在的输出端口参考起本地时 钟时间发送的光突发信号到达 AWGR的时刻与从基准框 FTL所在的输出 端口参考基准时间发送的携带相同时隙编号的光突发信号到达 AWGR的 时刻是相同的。
以一个线路框内的 OR和对应的 FTL为例， 该 OR所在的接收端口接 收到突发数据单元的前边界的时刻上， 其接收数据所参考的本地时钟时 间，与从接收到的突发信号所携带的 FTL所在的输出端口在发送该信号的 时刻的发送时隙编号标识的时间点一致， 则同一时刻上， OR所在的接收 端口所参考的本地时钟时间与 FTL 所在的输出端口发送数据所参考的本 地时钟时间之差正好等于光突发测试信号从 FTL 所在的输出端口传输到 OR所在的接收端口所消耗的传输时间。
由于与该 OR对应的 FTL与该 OR处于同一线路框内， 可以共用同一 本地参考时钟。 如果该 OR所在的接收端口接收到来自基准框的突发信号 所携带的发送时隙编号标识的期望时间点与该信号到达 OR所在的接收端 口时， OR所在的接收端口所参考的时钟时间不一致的时候， 相应的， 与 该 OR对应的位于同一线路框的 FTL所在的输出端口发送数据所参考的时 钟与基准框不同步， 参考该时钟发送出来的光突发信号将可能与基准框的 FTL所在的输出端口发送出来的光突发信号发生冲突。
实际上， 来自基准框的突发信号到达的 OR所在的接收端口所参考的 本地时间的设计期望数值由突发信号携带的发送时隙编号标识的时间点 指示。 该 OR所在的接收端口可以用于对其接收信号所参考的本地时钟的 时间计数器的计数值进行调整， 实现对该 OR本身所在的接收端口接收数 据所参考的时钟的时间相位的调整。 相应地， 由于该 OR的所在的接收端 口接收数据所参考的本地时间与该 OR对应的位于同一线路框的 FTL所在 的输出端口的发送数据所参考的本地时间两者存在固定时差， 该固定时差 即为该 OR所在的接收端口与该 OR对应的位于同一线路框的 FTL所在的 输出端口之间的光程差。 通常， 同一线路框内的 OR所在接收端口和 FTL 所在输出端口之间的光程差是可以与先获知的。 故， 该 OR所在的接收端 口还可以同时对与其对应的位于同一线路框的 FTL 所在的输出端口发送 数据所参考的相位时间进行调整。 具体的， 该 FTL/OR对所在线路框根据 该 OR所在的接收端口和与该 OR对应的位于同一线路框内的 FTL所在的 输出端口之间的光程差， 参考 OR所在的接收端口的本地时钟相位调整与 该 OR对应的位于同一线路框内的 FTL所在的输出端口的时钟相位。
对时钟相位进行调整的过程具体为： 将 OR所在的接收端口所参考的 本地时钟的时间校正到与来自基准线路框的携带时隙突发信号的到达时 刻所指示的设计期望时间， 并根据 OR所在的接收端口与该 OR对应的位 于同一线路框内的 FTL所在的输出端口之间的光程差进一步校正 FTL所 在的输出端口所参考的本地时钟的时间到期望的时间。
另外， 本实施例的光突发同步方法， 从与同一个 AWGR连接的多个 线路框中选择一个基准框，并由该基准框的 FTL所在的输出端口参考其本 地参考时钟向其他线路框发送携带时隙编号的光突发测试信号， 由其他线 路框的 OR所在的接收端口根据光突发测试信号的发送时隙、 达到时刻以 及与 OR相对应的相同线路框中的 FTL之间的光程差， 调整 OR和 FTL 所在接收和发送端口所参考的本地时钟， 能够在多框集群的光网络交换节 点内部实现各线路框之间的相位对齐， 从而使得各线路框发出的光突发信 号在同一时刻到达 AWGR, 实现了系统的同步， 也就解决了不同步引起的 碰撞问题。
进一步， 在上述实施例中， 为了提高每个 OR所在的接收端口和每个 OR对应的 FTL所在的输出端口之间的光程差的准确性 , 可以在 OR所在 的接收端口使用该光程差对与 OR对应的 FTL所在的输出端口的时间相位 进行调整之前，与某个 OR对应的位于同一线路框内的 FTL所在的输出端 口可以向该 OR所在的接收端口发送光突发环回信号， 所述光突发环回信 号携带有发送时隙编号。 该 OR所在的接收端口根据接收到的光突发环回 信号的时间和光突发环回信号中携带的发送时隙编号， 获取与该 OR对应 的位于同一线路框内的 FTL所在的输出端口之间的光程差。但获取光程差 的方法并不限于这一种， 例如： 由 OR所在的接收端口向与其对应的 FTL 所在的输出端口发送光突发环回信号。
由于各个线路框的时钟计数器依赖于本地晶体振荡器产生的标称频 率的计数脉冲来计数时间。 这些晶体振荡器的实际频率与标称频率之间存 在随机差异， 频率高的晶体振荡器， 将导致相位比基准框的时间相位超前 并累积。 特别地， 当各个线路框的本地时钟的振荡频率存在差异时， 还需 要进一步抑制这种由本地时钟振荡频率的漂移引起的相位差异。 针对该问 差异的步骤。 具体的， 与同一个 AWGR连接的每个线路框中的 OR所在 的接收端口根据预设的检测周期， 在连续两次或者两次以上（多次）接收 到来自基准线路框的基准光突发测试信号之间， OR 所在的接收端口参考 本地晶体频率产生的时钟脉冲计数并记录计数结果， 并根据先后两个计数 结果的差值与期望的设计数值（两个或者多个复帧周期的时间长度）之间 的差异， 调整 OR所在的接收端口所参考的时钟和与 OR对应的位于同一 线路框内的 FTL 所在的输出端口发送数据所参考的时钟基于执行本地晶 体频率产生的时钟脉冲计数器的吞吐脉冲进位控制。 其中， 光突发测试信 号是周期性发送的， 该光突发测试信号的发送周期一般比相位检测周期要 小 （两次或者多次基准突发信号周期为依次检测周期） 。 例如： 光突发测 试信号的发送周期为毫秒级， 而相位检测周期一般为秒级。 也就是说， 每 隔一段时间， 对本地时钟振荡频率要与基准框的频率进行一次比较， 实现 对频率差异和差异的变化（漂移） 的检测。 根据检测的结果， 更新吞吐脉 冲的控制的具体脉冲数量， 实时更新和补偿各个线路框与基准框的时钟计 数所依赖的晶体频率的差异。 对于明显的频率差异， 通过吞吐脉冲实现补 偿； 对于通过吞吐脉冲难以补偿的细微差异， 根据预设相位检测周期， 确 保每隔一段时间， 对本地时钟振荡频率漂移引起的可以识别的相位差异做 一次校准补偿。
具体的， 每个线路框可以采用基于较高频率的本地时钟的振荡频率产 生的时钟脉冲在两个或者多个来自基准框的光突发测试信号的两次到达 时刻之间对本地时钟脉冲进行计数（频率越高， 越能精确的探测差异和漂 移） 。 如果连续的两个或多个 （n大于等于 2个） 光突发测试信号达到时 刻之间的计数结果相同并且与设计期望一致， 说明本地时钟的振荡频率符 合设计预期并未发生漂移， 也未因为漂移产生额外的相位差异。 如果连续 的两个或多个 （n大于等于 2个） 光突发测试信号的达到时刻之间的计数 结果不相同并与设计期望有差异， 说明本地时钟的振荡频率与基准框频率 有差异， 而且差异正在发生变化（发生了漂移） ， 则根据最新的计数结果 与设计期望值的差值， 通过对本地时钟进行计数产生本地时间的计数器进 行吞脉冲或吐脉冲处理， 实现频率差异的补偿吸收调整。 对于因晶体振荡 器的频率高导致相位比基准框的时间相位超前并累积的线路框， 可以对该 线路框的时间相位进行吐脉冲处理， 使其计数器多计数若干脉冲后再行进 位， 从而实现晶振频率与基准框晶振频率差异的补偿。 反之， 对该线路框 的时间相位进行吞脉冲处理， 使其计数器少计数若干个脉冲就进位。 通过 这种方式可以进一步提高相位同步的准确性。
图 5为本发明另一实施例提供的光突发同步方法的流程图。 如图 5所 示， 本实施例的方法包括：
步骤 501、 从与同一个全光交换单元连接的多个线路框中选择一个线 路框作为基准框。
在本实施例中， 也以全光交换单元为 AWGR为例。
本步骤与步骤 401相类似， 在此不再赘述。
步骤 502、 与同一个全光交换单元连接的每个线路框中的 FTL所在的 输出端口分别在不同的开销时隙向基准框内的 OR所在的接收端口发送光 突发测试信号， 所述光突发测试信号携带有发送时隙编号。
在本实施例中， 由所有与同一个 AWGR连接的线路框中的 FTL所在 的输出端口分别向基准框内的 OR所在的接收端口发送光突发测试信号。 由基准框的 OR所在的接收端口检测每个线路框对应端口经 FTL发送的携 带时隙编号的光突发测试信号在基准框以 OR所在的接收端口所参考的本 地时钟的实际到达时刻和期望到达时刻之间的差异， 获得每个线路框发送 端口相对于基准框期望的相位差异。
步骤 503、 基准框内的 OR所在的接收端口根据其与每个线路框中的 FTL所在的输出端口的光程差、接收到每个线路框的 FTL所在的输出端口 发送的光突发测试信号的时间和所述光突发测试信号携带的发送时隙编 号，获取基准框内的 OR所在的接收端口与每个线路框内的 FTL所在的输 出端口的时间相位差，并将与每个线路框的 FTL所在的输出端口的时间相 位差分别发送给每个线路框的 FTL所在的输出端口。
具体的， 所述实际每个线路框发送端口相对于基准框期望的相位差 异， 由基准框内的 OR所在的接收端口根据接收到每个线路框对应端口经 FTL 发送的携带的发送时隙编号 （对应发送端口参考其本地时钟时间经 FTL发送光突发测试信号的时间）的光突发测试信号的实际到达时刻， 获 取每个线路框内的 FTL所在的输出端口参考其本地时钟时间经 FTL发送 的突发信号在基准线路框 OR及 OR所在的接收端口参考该接收端口的本 地时间的实际到达时刻与设计期望到达时刻之间的时间相位差， 并将与每 个线路框的 FTL 所在的输出端口所参考的时钟时间的时间相位差分别发 送给每个线路框的 FTL所在端口。
当线路框的 FTL与基准框的 OR之间存在时间相位差时， 基准框的 OR将时间相位差发送给该线路框的 FTL。
步骤 504、每个线路框的 FTL分别根据时间相位差，调整 FTL本身的 时钟相位。
接收到时间相位差的 FTL根据时间相位差，对本身的时钟相位进行调 整。 如果时间相位差表明 FTL本身的时钟相位超前， 则将 FTL所在的输 出端口的时钟时间计数器减少时间相位差对应的计数数值。 如果时间相位 差表明 FTL本身的时钟相位滞后， 则将 FTL所在的输出端口的时钟时间 计数器增加时间相位差对应的计数数值， 以实现相位对齐。
本实施例的光突发同步方法， 从与同一个 AWGR连接的多个线路框 中选择一个基准框， 每个线路框内的 FTL 均向基准框发送光突发测试信 号， 由基准框的 OR所在的接收端口根据光突发测试信号的发送时隙、 实 际到达时刻与在基准框 OR所在端口上的期望到达时刻的差， 获取各线路 框 FTL 所在端口发送数据的参考时钟时间与对准到基准框的期望时钟时 间相位差并分别反馈给各线路框， 各线路框分别根据时间相位差进行时间 相位调整， 能够在多框集群的光网络交换节点内部实现各线路框之间的相 位对齐，从而使得各线路框发出的光突发信号在同一时刻到达 AWGR, 实 现了系统的同步， 也就解决了不同步引起的碰撞问题。
特别地， 当各个线路框的本地时钟的振荡频率存在差异时， 还需要进 一步抑制这种由本地时钟振荡频率的漂移引起的相位差异。 针对该问题， 异的步骤。 具体的， 与同一个 AWGR连接的每个线路框中的 FTL所在的 输出端口参考起本地时钟时间， 根据预设复帧周期在对应其框编号的开销 时隙上重复发送突发开销信号， 基准框内的 OR所在端口获取连续的两次 或者多次同一线路框发送的突发信号在基准线路框 OR所在端口上的实际 到达时刻与基准框期望的到达时刻之间的差异， 如果差异不存在变化， 则 线路框的晶振频率与基准框晶振频率没有差异，不存在漂移；如果有变化， 随着时间的推移， 差异会变的越来越大， 我们称因为晶振频率差异引发在 相位的相对漂移。 对于明显的频率差异， 通过吞吐脉冲实现补偿； 对于通 过吞吐脉冲难以补偿的细微差异， 根据预设相位检测周期， 确保每隔一段 时间， 对本地时钟振荡频率漂移引起的可识别的相位差异做一次校准补 偿。
具体的， 基准线路框基于较高频率的时钟计数脉冲进行计数的基准框 OR所在端口的参考时钟计数器为参考， 同一线路框的不同突发的实际到 达时刻与期望到达时刻的差异如果一致， ，说明 FTL所在线路框和基准线 路框本地时钟的振荡频率一致而且未发生频率漂移， 未产生额外的相位差 异。 如果连续两个或者多个所描述即使到达时刻与期望到达时刻的时钟相 位差不相同， 说明本地时钟的振荡频率有差异， 发生了相位漂移， 则需要 根据两次实际到达时刻与期望到达时刻的差异的差值，通过更新对 FTL所 在的输出端口所参考的本地时钟进行计数产生本地时间的计数器进行吞 脉冲或吐脉冲处理， 实现对相位的调整。 通过这种方式可以进一步提高相 位同步的准确性。
上述图 4或图 5所示实施例从原理上对本发明提供的光突发同步方法 进行了说明， 以下实施例将结合实际应用场景对本发明的光突发同步方法 做进一步详细说明。
本实施例以图 3所示的与一个 AWGR连接有 4个线路框的结构为例 进行说明。
在实际应用中， 相对应的 S1和 S3部署在同一个线路框内。 如图 3所 示， 线路框 1、 2、 3和 4分别包括一个 S1和一个 OR, 并且每个 SI与一 个 FTL连接， 每个 S3与一个 OR连接。 也就是说， 一个 FTL和一个 OR 相对应， 并且部署在同一线路框内。 在每个线路框内， 都有一个具有一定 频率精度的本地晶振， 该本地晶振产生一个给定标称频率的时钟脉冲。 例 如： 标称频率可以为 38.88兆赫 （MHz ) 或 155.52MHz或 311.04MHz等。 同时， 在每个线路框中至少还会有一个时钟和同步模块， 用于对该标称频 率的时钟脉冲进行计数， 产生每个线路框需要的各种时间周期和边界， 例 如发送侧的本地参考时钟时间和接收侧的本地参考时钟时间。
例如： 如果 支设标称频率为 38.88MHz , 也就是说一秒钟内产生
38,880,000个时钟脉冲， 如果一秒钟对应 64800个时隙， 则一个时隙包括 600个连续时钟脉冲。 其中， 一个时隙不能全部用于发送光突发信号， 需 要为先后两个光突发信号之间保留一定的间隔， 以便于 FTL、 OR等硬件 能够为后一个光突发信号做好发送和接收准备。 在本发明各实施例中， 将 该保留间隔称为突发间隔 （ BurstGap ) 。 例如： 一个包含 600个时钟脉冲 的时隙， 可以用前 100个时钟脉冲和后 100个时钟脉冲作为突发间隔， 而 用中间 400个时钟脉冲来传输光突发信号。 其中， 每个时隙结束后可通过 进位来计数该时隙在复帧内的时隙编号 （ID ) 。
在本实施例中， 每个线路框内的时钟和同步模块除了为 S1和 FTL提 供了工作参考时钟， 还提供了基于时钟的计数值输出， 用来指示光突发信 号的发送边界（开始 /结束） 和时隙边界（开始 /结束） ， 并且还为 S3 和 OR记录光突发信号的到达时刻提供了条件。
基于上述为了实现各线路框发送的光突发信号能够在同一时间到达 AWGR, 即为了实现光突发同步， 本实施例选择线路框 1作为基准框。
其中， 一种具体实现光突发同步的方法包括：
线路框 1内的 FTL1— 1分别向线路框 1、 2、 3和 4内的 OR1— 1、 OR2 1、 OR3— 1 和 OR4— 1发送光突发测试信号。 具体的， 在本实施例中， 定义 4 个开销帧构成一个开销复帧， 每个开销帧包括 81 时隙， 其中， 每个开销 帧中有一个时隙用于发送光突发测试信号， 称为开销时隙， 每个开销帧中 的开销时隙的位置是固定的； 每个时隙包括 600个时钟脉冲。 其中， 开销 复帧的第 0帧的开销时隙分配给基准框自发自收； 开销复帧的第 1帧的开 销时隙分配给线路框 1和线路框 2之间的双向通信 （包括发送和接收） ； 开销复帧的第 2帧的开销时隙分配给线路框 1和线路框 3之间的双向通信； 开销复帧的第 3帧的开销时隙分配给线路框 1和线路框 4之间的双向通信。
在此说明， 开销复帧包含的开销帧的个数要大于或等于每个 AWGR 连接的线路框的个数。 例如： 当一个 AWGR同时连接 200个线路框时， 至少需要定义 200个开销帧构成一个开销复帧。 其中， 每个开销帧的分配 方法与上述相同。
线路框 1分别在分配给线路框 1、 2、 3和 4使用的开销帧的开销时隙 上向每个线路框 1、 2、 3和 4中的 OR1— 1、 OR2— 1、 OR3 1和 OR4— 1发 送光突发测试信号， 并且在光突发测试信号中携带发送该光突发测试信号 的时隙编号。 在本实施例中， 任何一个开销时隙上， 只有一个线路框内的 OR (包括基准框本身在内） 和线路框 1在进行双向通信。 对线路框 1 而 言， 前后两个光突发测试信号之间的间隔为时间为 81 *4-1=323 , 具有强大 的频率差异吸收能力， 不会轻易发生开销突发之间的重叠碰撞。
对线路框 1、 2、 3和 4来说， 都会周期性的接收到来自线路框 1 (作 为基准线路框）在不同开销帧的开销时隙上发送的光突发测试信号。 线路 框 1、 2、 3和 4中的 OR1— 1、 OR2— 1、 OR3 1和 OR4— 1分别记录接收到 光突发测试信号时的本地系统时间， 该本地系统时间是由线路框 1、 2、 3 和 4中的时钟和同步模块对本地晶振进行计数生成的供 ORl—l、 OR2— 1、 OR3— 1和 OR4— 1使用， 而记录下来的本地系统时间即为光突发测试信号 的到达时刻。 其中， 线路框 1、 2、 3和 4中的 OR1— 1、 OR2— 1、 OR3— 1和 OR4— 1本地系统时间与线路框 1内的 FTL1— 1的本地系统时间之间存在固 定的时差 （即光程差）， 因此， 线路框 1、 2、 3和 4内的 OR1— 1、 OR2— 1、 OR3— 1和 OR4— 1根据记录下来的光突发测试信号的到达时刻、 来自线路 框 1的基准光突发测试信号内携带的时隙编号， 对各自的 OR所参考的本 地系统时钟时间进行校准。 另外， 由于每个线路框内的 FTL侧的本地系统 时间和 OR侧的本地系统时间之间也存在固定的时差， 故线路框 2、 3和 4 内的 OR2— 1、 OR3 1和 OR4— 1除了对各自的本地系统时间进行校准之外， 还可以对同一线路框内的 FTL2— 1、 FTL3 1和 FTL4— 1侧的本地系统时间 进行校准。在实际应用中，同一线路框中 OR侧的本地系统时间可以是 FTL 的本地系统时间的延迟输出， 也就是说， OR需要将对其本地系统时间进 行校准时的时间差增加相应延迟后来校准同一线路框内的 FTL 的本地系 统时间。 延迟是指同一线路框内 OR与 FTL之间的光程差。
在上述技术方案中， 线路框 1、 2、 3和 4内的 OR1— 1、 OR2— 1、 OR3 1 和 OR4— 1与线路框 1内的 FTLl— 1之间的光程差是预先获知的。线路框 1、 2、 3和 4内的 OR1— 1、 OR2— 1、 OR3 1和 OR4— 1分别与 FTL1— 1、 FTL2— 1、 FTL3— 1和 FTL4— 1之间的光程差也是预先获知的。
本实施例通过定义开销复帧并引入一个周期性的开销时隙用于实现 同步， 在开销时隙上发送的光突发测试信号可实现任意线路框之间的来回 通信， 可直接由硬件完成同步控制， 不需要软件和网管的介入， 从而解决 了受软件处理速度的限制的问题。
在上述技术方案中，为了提高对各个 OR和 FTL的本地系统时间的校 准精度， 本实施例中， 在每个开销复帧中某一个开销时隙， 可以定义为环 回时隙， 不仅基准框在该时隙内向第一框（其本身）发送开销突发， 每个 线路框都向自己发送环回开销突发。用于供每个线路框内的 FTL向该线路 框内的 OR发送光突发环回信号， 以对同一线路框内的 FTL和 OR之间的 光程差进行实时测试。 较为优选地， 该环回时隙为第一个开销时隙。
以图 3所示结构为例， 线路才匡 1、 2、 3和 4内的 FTL1— 1、 FTL2— 1、 FTL3 1 和 FTL4— 1 分别在各自的环回时隙内向 OR1— 1、 OR2— 1、 OR3 1 和 OR4— 1 发送光突发环回信号， 并在光突发环回信号携带发送该光突发 环回信号的时隙编号。 线路才匡 1、 2、 3和 4内的 OR1— 1、 OR2— 1、 OR3 1 和 OR4— 1 记录光突发环回信号的到达时刻， 将到达时刻与光突发环回信 号内携带的时隙编号对应的时间点做差， 获取彼此之间的光程差， 为 OR1— 1、 OR2— 1、 OR3 1和 OR4— 1分别对 FTL1— 1、 FTL2— 1、 FTL3 1和 FTL4— 1的本地系统时间进行校准打下基础。
通常， 某个线路框内会包含多个 FTL和多个 OR, 且每个 FTL和对应 的 OR会连接不同的 AWGR。 每个 AWGR对应一个平面， 平面之间不相 关， 也就是说， 对于连接同一个 AWGR的 FTL和 OR之间需要实现同步， 且其同步与连接其他 AWGR的 FTL和 OR不相关。 在本实施例中从每个 线路框中选择一个 OR所在的接收端口用来进行同步。 该 OR所在的接收 端口可能会接收到多种光突发信号， 故该 OR所在的接收端口首先可以对 其接收到的所有光突发信号进行过滤， 从中提取出光突发环回信号和光突 发测试信号。 本实施例除了由 OR所在的接收端口接收突发数据所参考的 时间相位进行时间校准之外， 还可以将这两个信号的到达时刻和这两个信 号中携带的时隙编号送到时钟和同步模块， 由时钟和同步模块进行时间校 准。
进一步， 在上述技术方案的基础上， 在一些场景中， 每个线路框的本 地晶振固有频率相互之间不一致（存在差异） ， 还可能会随温度等的变化 发生漂移， 这种差异和漂移引起基于其发生的频率计数产生的时钟单位实 际长度在各个线路框上存在差异。 本实施例提供一种抑制本地晶振固有频 率差异以及其漂移引起的时钟单位实际长度和相位变化和飘移的方法。 每 个线路框中的 OR所在接收端口可以使用较高频率的时钟脉冲在两次或者 多次光突发测试信号之间对较高频率的本地晶振频率脉冲进行计数并记 录计数结果， 并获取至少两个计数结果， 然后通过判断至少两个计数结果 是否相同， 来判断是否发生晶振漂移， 并根据计数结果的差值来进行时间 校准。 其中， 对两个光突发测试信号之间的时间间隔进行计数的操作可以 每隔一段时间执行一次， 即按照预设的相位检测周期， 周期性的执行计数 操作， 并通过将两个相位检测周期得到的计数结果进行比较判断是否需要 进行相位调整， 这样可以减轻整个系统的开销和负担。 仍以图 3中的线路 框 2为例， 假设线路框 2中的 OR2— 1每隔一段时间 （例如 1秒钟 ) 就在 两次光突发测试信号之间对本地晶振进行计数， 在得到两个计数结果后， 将两个计数结果进行比较。 例如： 如果第一个计数结果计数了 9,720,000 个时钟脉冲， 第二个计数结果为 9,720,000+9.72个时钟脉冲， 前后两次计 数结果不同， 说明线路框 2的本地晶振的时钟脉冲频率发生了漂移， 比之 前要快 lppm, 故需要补偿这个频率偏差， 通过吞吐脉冲对本地时钟和同 步模块的时隙计数进行校准处理。
图 6为本发明一实施例提供的用于实现本发明实施例提供的光突发同 步方法的线路框的结构示意图。 如图 6所示， 本实施例的线路框包括： 接 收端电交换单元 61和发送端电交换单元 62。 接收端电交换单元 61包括： 多个接收端口 611、多个输出端口 612和每个输出端口 612连接的 FTL613。 发送端电交换单元 62包括： 多个接收端口 621、 多个输出端口 622和每个 接收端口 621连接的 OR623。 其中， FTL所连接的输出端口又被称为 FTL 所在的输出端口； OR所连接的接收端口又被称为 OR所在的接收端口。 一个线路框往往包含若干对 FTL613和 OR623端口对。其中，每个 FTL613 所在的输出端口 612 , 用于在该线路框被选择为基准框时， 向与该基准线 路框连接于同一个全光交换单元的其他线路框中的 OR所在的接收端口发 送光突发测试信号， 以使其他线路框中的 OR所在的接收端口根据其与基 准框内发送基准测试信号的 FTL613所在的输出端口 612的光程差、 其他 线路框中的 OR所在的接收端口接收到光突发测试信号的实际时间和光突 发测试信号携带的发送时隙编号， 与其他线路框的 OR所在的接口端口接 收数据所参考的本地参考时钟进行比较， 而获取来自基准框的基准突发测 试信号在其他线路框的 OR 所在的接收端口的到达相位与其他线路框的 OR所在的接收端口的本地接收参考时间之间的相位差 （简称为与基准框 内的 FTL所在的输出端口的时间相位差 ) , 并根据获取的时间相位差调整 其他线路框内的 OR所在的接收端口接收突发数据所参考的时钟相位和与 该其他线路框内的 OR对应的位于同一线路框内的 FTL所在的输出端口发 送突发数据所参考的时钟相位。
每个 OR623所在的接收端口 621 ,用于在与该线路框连接于同一个全 光交换单元的其他线路框中的一个线路框被选为基准框时， 接收由基准框 内的 FTL所在的输出端口经 FTL发送的光突发测试信号，并根据该 OR623 所在的接收端口 621到基准框内发送光突发测试信号的 FTL所在的输出端 口的光程差、 接收到光突发测试信号的实际时间和光突发测试信号携带的 发送时隙编号， 与该 OR623所在的接收端口 621接收突发数据所参考的 本地参考时钟进行比较， 而获取来自基准框的基准突发测试信号在该 OR623所在的接收端口 621 的到达相位与该 OR623所在的接收端口 621 的本地接收参考时间的相位差（简称为与基准框内发送光突发测试信号的 FTL 所在的输出端口的时间相位差） ， 并根据时间相位差调整该 OR623 所在的接收端口 621接收突发数据所参考的时钟相位和与该 OR623对应 的位于同一线路框内的 FTL613所在的输出端口 612发送突发数据所参考 的时钟相位。
其中， 本实施例的线路框中的 OR623所在的接收端口 621具体根据 所述的时间相位差与 OR623所在的输出端口和与该 OR623对应的位于同 一线路框内的 FTL613所在的输出端口 612之间的光程差， 调整该 OR623 对应的位于同一线路框内的 FTL613所在的输出端口 612发送突发数据所 参考的时钟相位 （或者说是突发数据发送所参考的时钟相位） 。 本实施例的节点设备可用于执行图 4所示光突发同步方法的流程， 其 具体工作原理不再赘述， 详见方法实施例的描述。
进一步， 本实施例的线路框的 FTL613所在的输出端口 612还经所连 接的 FTL613向与该 FTL613对应的位于同一线路框的 OR623发送光突发 环回信号， 所述光突发环回信号携带有发送时隙编号。
相应的， 本实施例线路框的 OR623所在的接收端口 621接收光突发 环回信号， 并根据接收到光突发环回信号的时间和光突发环回信号携带的 发送时隙编号，获取与该 OR623对应的位于同一线路框内的 FTL613所在 的输出端口 612之间的光程差。 OR623所在的接收端口 621结合所获取 的时间相位差和该 FTL613所在的输出端口 612到该 OR623所在的接收端 口 621的光程差， 调整 FTL613所在的输出端口 612发送数据所参考的时 钟相位。
更进一步， 本实施例提供的线路框的 OR623所在的接收端口 621还 根据预设相位检测周期， 在连续两次或多次接收到光突发测试信号之间对 本地时钟计数结果与设计期望数值之间的差异， 调整 OR623 所在的接收 端口 621接收突发数据所参考的时钟相位 （或者说调整 OR623所在的接 收端口 621 上的突发数据接收所参考的时钟相位， 又或说， 调整 OR623 所在的接收端口 621的时钟相位指示计数器时间单位的计数节拍数） ， 并 调整与该 OR623对应的位于同一线路框内的 FTL613所在的输出端口 612 的时钟相位指示计数器时间单位的计数节拍数（或者说调整 FTL613所在 的输出端口 612上的突发数据发送所参考的时钟相位） ， 从而矫正时间单 位长度在各个线路框上的不一致。
其中， 全光交换单元可由 AWGR实现， 但不限于此。
在实际应用中， 上述光突发同步流程中的控制和管理功能可由线路框 中的中央处理单元 （ Central Processing Unit; 简称为： CPU ) 及软件子系 统来实现。 例如： 光突发测试信号的接收与发送可由 CPU及软件子系统 完成； 而关于时间相位差的获取以及对时钟相位的调整可由时钟和同步模 块来完成。
本实施例的线路框在未被选为基准框时，接收基准框的 FTL所在的输 出端口发送的光突发测试信号， 并由其 OR所在的接收端口根据光突发测 试信号的发送时隙、到达时刻以及与线路框内的 FTL所在的输出端口之间 的光程差， 获取本实施例的线路框与基准框的时间相位差， 线路框的 OR 根据时间相位差进行本身所在接收端口接收突发数据所参考的时间相位 和 FTL所在输出端口发送突发数据所参考的时间相位的调整，能够在多框 集群的光网络交换节点内部实现各线路框之间的相位对齐， 从而使得各线 路框发出的携带有相同时隙编号的光突发信号在同一时刻到达 AWGR,实 现了系统的同步， 也就解决了不同步引起的碰撞问题。
图 7为本发明另一实施例提供的用于实现本发明实施例提供的光突发 同步方法的线路框的结构示意图。 如图 7所示， 本实施例的线路框包括： 接收端电交换单元 71和发送端电交换单元 72。 其中， 接收端电交换单元 71包括： 多个接收端口 711、 多个输出端口 712和每个输出端口 712所连 接的 FTL713。 发送端电交换单元 72包括： 多个接收端口 721、 多个输出 端口 722和每个接收端口 721连接的 OR723。 其中， 每个 FTL所连接的 输出端口又称为 FTL所在的输出端口，每个 OR所连接的接收端口又称为 OR所在的接收端口。
其中， 每个 FTL713所在的输出端口， 用于向与本实施例的线路框连 接于同一个全光交换单元且被选择为基准框的线路框内的 OR发送光突发 测试信号，并接收基准框内的 OR所在的接收端口发送的线路框的 FTL713 所在的输出端口与基准框内的 OR所在的接收端口之间的时间相位差， 并 根据时间相位差调整 FTL 所在的输出端口上的电突发数据发送所参考的 时钟相位。 基准框内的 OR所在的接收端口检测到的本实施例的线路框内 的 FTL713所在的输出端口经过所连接的 FTL713发送的携带时隙编号的 光突发测试信号在基准框的 OR所在的接收端口上的到达时间与基准框的 OR所在的接收端口对其的期望到达时间相位的差异， 作为时间相位差。 具体的， 基准框内的 OR所在的接收端口根据接收到本实施例的线路框内 的 FTL713所在的输出端口发送的光突发测试信号的在基准框的 OR所在 的接收端口上的实际到达时间相位、 基准框内的 OR所在的接收端口与本 实施例的线路框内的 FTL713所在的输出端口之间的光程差和光突发测试 信号携带的发送时隙编号， 与基准框内的 OR所在的接收端口对来自其他 线路框的携带相同时隙编号的光突发测试信号的期望到达时间相位的差 异而获取所述时间相位差。
每个 OR723所在的接收端口 721 , 用于在线路框被选为基准框时， 接 收与基准框连接于同一个全光交换单元的其他线路框内的 FTL 所在的输 出端口发送的光突发测试信号，并根据其与其他线路框内的 FTL所在的输 出端口的光程差、接收到线路框内的 FTL所在的输出端口发送的光突发测 试信号的时间和光突发测试信号携带的发送时隙编号， 与基准框的 OR所 在的接收端口上期望的特定时隙编号的光突发测试信号的期望到达时间 的比较结果， 获取与其他线路框内的 FTL 所在的输出端口的时间相位差 (即获取与其他线路框内的 FTL 所在的输出端口发送突发数据所参考的 时间相位与期望的时间相位的差异） ， 并将该时间相位差发送给其他线路 框内的 FTL所在的输出端口， 以使其他线路框内的 FTL所在的输出端口 根据时间相位差调整器上的电突发数据发送所参考的时钟相位， 以使其他 线路框的 FTL所在的输出端口发送数据所参考的时间相位符合设计期望。
本实施例的线路框可用于执行图 5所示光突发同步方法的流程， 其具 体工作原理不再赘述， 详见方法实施例的描述。
更进一步， 本实施例提供的线路框中的 FTL713所在的输出端口 712 还根据预设检测周期， 在连续两次或多次接收到基准框内的 OR所在的接 收端口返回的时间相位差之间对本地时钟计数并记录计数结果， 并根据先 后两个计数结果，调整 FTL所在的输出端口上电突发数据发送所参考的时 钟相位。
其中， 由于与 FTL713 位于同一线路框内的 OR723 的时钟相位是 FTL713的时钟相位的延迟，故 FTL713对本身的时钟相位的调整相当于对 OR723的时钟相位也做了调整。
其中， 全光交换单元可由 AWGR实现， 但不限于此。
本实施例的线路框在未被选为基准框时，由其 FTL向基准框发送光突 发测试信号， 由基准框的 OR所在的接收端口根据光突发测试信号的发送 时隙、到达时刻以及与线路框的 FTL所在的输出端口之间的光程差， 获取 本实施例的线路框与基准框的时间相位差并分别反馈给本实施例的线路 框， 本实施例线路框的 FTL根据时间相位差进行时间相位调整， 能够在多 框集群的光网络交换节点内部实现各线路框之间的相位对齐， 从而使得各 线路框发出的带有相同时隙编号的光突发信号在同一时刻到达 AWGR,实 现了系统的同步， 也就解决了不同步引起的碰撞问题。
本发明一实施例提供一种多框集群的光网络交换节点， 包括线路框和 全光交换单元。
本实施例的线路框为图 6所示的线路框， 其工作原理可参见图 4所示 实施例实现， 其具体结构如图 6所示， 在此不再赘述。
在本实施例中， 全光交换单元包括： 多个输入端和多个输出端； 每个 接收端电交换单元的每个输出端口通过所连接的 FTL 分别与全光交换单 元的一个输入端相连接， 每个发送端电交换单元的每个接收端口通过所连 接的 OR分别与全光交换单元的一个输出端相连接。
每个接收端电交换单元， 用于通过接收端电交换单元的多个接收端口 接收多路数据单元， 对接收到的多路数据单元进行第一级电交换， 并通过 接收端电交换单元的多个输出端口所连接的 FTL 进行电光转换后输出给 全光交换单元。
全光交换单元， 用于对接收端电交换单元输出的多路数据单元进行全 光空分交换后输出给发送端电交换单元。
发送端电交换单元， 用于通过发送端电交换单元的多个接收端口所连 接的 OR对全光交换单元输出的多路数据单元进行光电转换， 然后对光电 转换后的多路数据单元进行第二级电交换后通过发送端电交换单元的多 个输出端口输出多路数据单元。
其中， 全光交换单元可由 AWGR实现。
本实施例提供的多框集群的光网络交换节点的具体结构、 连接关系以及 相关模块的功能可参见图 1或图 2所示， 在此不再赘述。
本实施例的多框集群的光网络交换节点，基于上述实施例提供的线路框， 解决了光突发同步的问题， 实现了电交换 -全光交换-电交换的交换方式， 实现 了基于 OTN的多框集群系统， 增加了多框集群系统的容量、 降低了功耗。
本发明另一实施例提供一种多框集群的光网络交换节点， 包括线路框和 全光交换单元。
本实施例的线路框为图 7所示的线路框， 其工作原理可参见图 5所示实 施例的描述， 其实现结构参见图 7, 在此不再赘述。
在本实施例中， 全光交换单元包括： 多个输入端和多个输出端； 每个 接收端电交换单元的每个输出端口通过所连接的 FTL 分别与全光交换单 元的一个输入端相连接， 每个发送端电交换单元的每个接收端口通过所连 接的 OR分别与全光交换单元的一个输出端相连接。
每个接收端电交换单元， 用于通过接收端电交换单元的多个接收端口 接收多路数据单元， 对接收到的多路数据单元进行第一级电交换， 并通过 接收端电交换单元的多个输出端口所连接的 FTL 进行电光转换后输出给 全光交换单元。
全光交换单元， 用于对接收端电交换单元输出的多路数据单元进行全 光空分交换后输出给发送端电交换单元。
发送端电交换单元， 用于通过发送端电交换单元的多个接收端口所连 接的 OR对全光交换单元输出的多路数据单元进行光电转换， 然后对光电 转换后的多路数据单元进行第二级电交换后通过发送端电交换单元的多 个输出端口输出多路数据单元。
其中， 全光交换单元可由 AWGR实现。
本实施例提供的多框集群的光网络交换节点的具体结构、 连接关系以及 相关模块的功能可参见图 1或图 2所示， 在此不再赘述。
本实施例的多框集群的光网络交换节点，基于上述实施例提供的线路框， 解决了光突发同步的问题， 实现了电交换 -全光交换-电交换的交换方式， 实现 了基于 OTN的多框集群系统， 增加了多框集群系统的容量、 降低了功耗。
本领域普通技术人员可以理解： 实现上述方法实施例的全部或部分步 骤可以通过程序指令相关的硬件来完成， 前述的程序可以存储于一计算机 可读取存储介质中， 该程序在执行时， 执行包括上述方法实施例的步骤； 而前述的存储介质包括： ROM、 RAM, 磁碟或者光盘等各种可以存储程 序代码的介质。
最后应说明的是： 以上实施例仅用以说明本发明的技术方案， 而非对 其限制； 尽管参照前述实施例对本发明进行了详细的说明， 本领域的普通 技术人员应当理解： 其依然可以对前述各实施例所记载的技术方案进行修 改， 或者对其中部分技术特征进行等同替换； 而这些修改或者替换， 并不 使相应技术方案的本质脱离本发明各实施例技术方案的精神和范围。

Claims

权 利 要 求 书
1、 一种光突发同步方法， 其特征在于， 包括：
从与同一个全光交换单元连接的多个线路框中选择一个线路框作为 基准框，所述基准框内的波长可调光发送激光器 FTL所在的输出端口通过 所述 FTL 分别向与所述同一个全光交换单元连接的多个线路框中的光接 收模块 OR所在的接收端口发送光突发测试信号， 所述光突发测试信号携 带有发送时隙编号；
与所述同一个全光交换单元连接的每个线路框中的 OR所在的接收端 口根据其到所述基准框内的 FTL所在的输出端口的光程差、接收所述光突 发测试信号的时间点和所述光突发测试信号中携带的发送时隙编号， 获取 与所述基准框内的 FTL所在的输出端口的时间相位差，并根据所述时间差 相位调整所述 OR所在的接收端口上的电突发数据接收所参考的时钟相位 和与所述 OR对应的位于同一线路框内的 FTL所在的输出端口上的电突发 数据发送所参考的时钟相位。
2、 根据权利要求 1 所述的光突发同步方法， 其特征在于， 与所述同 一个全光交换单元连接的每个线路框中的 OR所在的接收端口根据所述时 间相位差调整与所述 OR对应的位于同一线路框内的 FTL所在的输出端口 上的电突发数据发送所参考的时钟相位包括：
与所述同一个全光交换单元连接的每个线路框中的 OR所在的接收端 口根据所述时间相位差和所述 OR所在的接收端口和与所述 OR对应的位 于同一线路框内的 FTL所在的输出端口的光程差，调整与所述 OR对应的 位于同一线路框内的 FTL 所在的输出端口上的电突发数据发送所参考的 时钟相位。
3、 根据权利要求 2所述的光突发同步方法， 其特征在于， 与所述同 一个全光交换单元连接的每个线路框中的 OR所在的接收端口根据所述时 间相位差和所述 OR所在的接收端口和与所述 OR对应的位于同一线路框 内的 FTL所在的输出端口的光程差，调整与所述 OR对应的位于同一线路 框内的 FTL 所在的输出端口上的电突发数据发送所参考的时钟相位之前 包括：
与所述 OR对应的位于同一线路框内的 FTL所在的输出端口向所述 OR所在的接收端口发送光突发环回信号， 所述光突发环回信号携带有发 送时隙编号；
所述 OR所在的接收端口根据接收到所述光突发环回信号的时间和所 述光突发环回信号中携带的发送时隙编号， 获取与所述 OR对应的位于同 —线路框内的 FTL所在的输出端口之间的光程差。
4、 根据权利要求 1或 2或 3所述的光突发同步方法， 其特征在于， 还包括：
与所述同一个全光交换单元连接的每个线路框中的 OR所在的接收端 口根据预设相位检测周期， 在连续两次或两次以上接收到所述光突发测试 信号之间对本地时钟计数并记录计数结果， 并根据先后两个所述计数结 果， 调整所述 OR所在的接收端口上的电突发数据接收所参考的时钟相位 和与所述 OR对应的位于同一线路框内的 FTL所在的输出端口上的电突发 数据发送所参考的时钟相位。
5、 根据权利要求 1或 2或 3或 4所述的光突发同步方法， 其特征在 于， 所述全光交换单元为列阵波导光栅路由器 AWGR。
6、 一种光突发同步方法， 其特征在于， 包括：
从与同一个全光交换单元连接的多个线路框中选择一个线路框作为 基准框；
与所述同一个全光交换单元连接的每个所述线路框中的波长可调光 发送激光器 FTL所在的输出端口通过所述 FTL分别向所述基准框内的光 接收模块 OR所在的接收端口发送光突发测试信号， 所述光突发测试信号 携带有发送时隙编号；
所述基准框内的 OR所在的接收端口根据其与每个线路框中的 FTL所 在的输出端口的光程差、接收到每个线路框的 FTL所在的输出端口发送的 光突发测试信号的时间和所述光突发测试信号携带的发送时隙编号， 获取 所述基准框内的 OR所在的接收端口与每个线路框内的 FTL所在的输出端 口的时间相位差，并将与每个线路框的 FTL所在的输出端口的时间相位差 分别发送给每个线路框的 FTL所在的输出端口；
每个线路框的 FTL所在的输出端口分别根据所述时间相位差，调整所 述 FTL所在的输出端口上的电突发数据发送所参考的时钟相位。
7、 根据权利要求 6所述的光突发同步方法， 其特征在于， 还包括： 与所述同一个全光交换单元连接的每个线路框中的 FTL 所在的输出 端口根据预设相位检测周期， 在连续两次或两次以上接收到所述基准框内 的 OR所在的接收端口返回的时间相位差之间对本地时钟计数并记录计数 结果， 并根据先后两个所述计数结果， 调整所述 FTL所在的输出端口上电 突发数据发送所参考的时钟相位。
8、 根据权利要求 6或 7所述的光突发同步方法， 其特征在于， 所述 全光交换单元为列阵波导光栅路由器 AWGR。
9、 一种线路框， 其特征在于， 包括：
接收端电交换单元和发送端电交换单元； 所述接收端电交换单元包括 多个接收端口、 多个输出端口和每个输出端口所连接的波长可调光发送激 光器 FTL; 所述发送端电交换单元包括多个接收端口、 多个输出端口和每 个接收端口所连接的光接收模块 OR;
每个所述 FTL所在的输出端口， 用于在所述线路框被选为基准框时， 向与所述基准线路框连接于同一个全光交换单元的其他线路框中的光接 收模块 OR所在的接收端口发送光突发测试信号，以使其他线路框中的 OR 所在的接收端口根据其与所述基准框内发送所述基准测试信号的 FTL 所 在的输出端口的光程差、接收所述光突发测试信号的时间和所述光突发测 试信号携带的发送时隙编号 ,获取与所述基准框内的 FTL所在的输出端口 的时间相位差， 并根据所述时间相位差调整所述 OR所在接收端口上的电 突发数据接收所参考的时钟相位和与所述 OR对应的位于同一线路框内的 FTL所在的输出端口上的电突发数据发送所参考的时钟相位；
每个所述 OR所在的接收端口， 用于在与所述线路框连接于同一个全 光交换单元的其他线路框中的一个线路框被选为基准框时， 接收由所述基 准框内的 FTL所在的输出端口通过所述 FTL发送的光突发测试信号， 并 根据其到所述基准框内发送所述光突发测试新信号的 FTL 所在的输出端 口的光程差、 接收所述光突发测试信号的时间和所述光突发测试信号携带 的发送时隙编号，获取与所述基准框内发送所述光突发测试信号的 FTL所 在的输出端口的时间相位差， 并根据所述时间相位差调整所述 0 R所在的 接收端口上的电突发数据接收所参考的时钟相位和与 OR对应的位于同一 线路框内的 FTL所在的输出端口上的电突发数据发送所参考的时钟相位。
10、 根据权利要求 9所述的线路框， 其特征在于， 所述 OR所在的接 收端口具体根据所述时间相位差和所述 OR所在的输出端口和与所述 OR 对应的位于同一线路框内的 FTL 所在的输出端口的光程差， 调整与所述 OR对应的位于同一线路框内的 FTL所在的输出端口的电突发数据发送所 参考的时钟相位。
11、 根据权利要求 10所述的线路框， 其特征在于， 每个所述 FTL所 在的输出端口还用于向与所述 FTL对应的位于同一线路框内的 OR所在的 接收端口发送光突发环回信号， 所述光突发环回信号携带有发送时隙编 号；
所述 OR所在的接收端口还用于根据接收到所述光突发环回信号的时 间和所述光突发环回信号中携带的发送时隙编号， 获取与所述 OR对应的 位于同一线路框内的 FTL所在的输出端口之间的光程差。
12、 根据前案例要求 9或 10或 11所述的线路框， 其特征在于， 所述 OR所在的接收端口还用于根据预设相位检测周期， 在连续两次或两次以 上接收到所述光突发测试信号之间对本地时钟计数并记录计数结果， 并根 据先后两个所述计数结果， 调整所述 OR所在的接收端口上的电突发数据 接收所参考的时钟相位和与所述 OR对应的位于同一线路框内的 FTL所在 的输出端口上的电突发数据发送所参考的时钟相位。
13、 一种线路框， 其特征在于， 包括：
接收端电交换单元和发送端电交换单元； 所述接收端点交换单元包括 多个接收端口、 多个输出端口和每个输出端口所连接的波长可调光发送激 光器 FTL; 所述发送端电交换单元包括多个接收端口、 多个输出端口和每 个接收端口所连接的光接收模块 OR;
每个所述 FLT所在的输出端口，用于从所在线路框向与所述线路框连 接于同一个全光交换单元且被选择为基准框的线路框内的 OR 所在的接 收端口发送光突发测试信号， 并接收所述基准框内的 OR所在的接收端口 发送的所述线路框的 FTL所在的输出端口与所述基准框内的 OR所在的接 收端口的时间相位差，并根据所述时间相位差调整所述 FTL所在的输出端 口上的电突发数据发送所参考的时钟相位； 所述光突发测试信号携带有发 送时隙编号； 所述时间相位差是由所述基准框内的 OR所在的接收端口根 据其与所述线路框内发送所述光突发测试信号的 FTL 所在的输出端口的 光程差、接收到所述线路框的 FTL所在的输出端口发送的光突发测试信号 的时间和所述光突发测试信号携带的发送时隙编号获取的；
每个 OR所在的接收端口， 用于在所述线路框被选为基准框时， 接收 与所述基准线路框连接于同一个全光交换单元的其他线路框内的 FTL 所 在的输出端口发送的光突发测试信号，并根据其与其他线路框内的 FTL所 在的输出端口的光程差、接收到其他线路框的 FTL所在的输出端口发送的 光突发测试信号的时间和所述光突发测试信号中的发送时隙编号， 获取与 其他线路框内的 FTL所在的输出端口的时间相位差 ,并将所述时间相位差 发送给其他线路框内的 FTL所在的输出端口， 以使其他线路框内的 FTL 所在的输出端口根据所述时间相位差调整其上的电突发数据发送所参考 的时钟相位。
14、 根据权利要求 13 所述的线路框， 其特征在于， 所述线路框内的 FTL所在的输出端口还用于根据预设相位检测周期， 在连续两次或两次以 上接收到所述基准框内的 OR所在的接收端口返回的时间相位差之间对本 地时钟计数并记录计数结果， 并根据先后两个所述计数结果， 调整所述 FTL所在的输出端口上电突发数据发送所参考的时钟相位。
15、 一种多框集群的光网络交换节点， 其特征在于， 包括权利要求 9-12 任一项所述的线路框和全光交换单元；
所述全光交换单元包括： 多个输入端和多个输出端； 每个所述接收端 电交换单元的每个输出端口通过所连接的 FTL 分别与所述全光交换单元 的一个输入端相连接， 每个所述发送端电交换单元的每个接收端口通过所 连接的 OR分别与所述全光交换单元的一个输出端相连接；
每个所述接收端电交换单元， 用于通过所述接收端电交换单元的多个 接收端口接收多路数据单元， 对接收到的多路数据单元进行第一级电交 换，并通过所述接收端电交换单元的多个输出端口所连接的 FTL进行电光 转换后输出给所述全光交换单元；
所述全光交换单元， 用于对所述接收端电交换单元输出的多路数据单 元进行全光空分交换后输出给所述发送端电交换单元； 所述发送端电交换单元， 用于通过所述发送端电交换单元的多个接收 端口所连接的 OR对所述全光交换单元输出的多路数据单元进行光电转 换， 然后对光电转换后的多路数据单元进行第二级电交换后通过所述发送 端电交换单元的多个输出端口输出多路数据单元。
16、根据权利要求 15所述的多框集群的光网络交换节点， 其特征在于， 所述全光交换单元为列阵波导光栅路由器 AWGR;
每个所述 FTL与一个所述 AWGR的一个输入端相连接；每个所述 OR 与一个所述 AWGR的一个输出端相连接； 相对应的一个 FTL和一个 OR 位于同一线路框内， 并分别与同一个 AWGR的一个输入端和一个输出端 连接；
所有所述接收端电交换单元的相同编号的输出端口分别通过所连接 的 FTL连接于同一个 AWGR的不同输入端； 所有所述发送端电交换单元 的相同编号的输入接口分别通过所连接的 OR连接于同一个 AWGR的不 同输出端。
17、 根据权利要求 16所述的多框集群的光网络交换节点， 其特征在 于，每个所述 FTL, 用于接收所述接收端电交换单元上与所述 FTL相连的 输出端口上的电时分突发数据单元， 并将所述电时分突发数据单元转换为 时分光突发信号后发送给所述 AWGR;
每个所述 AWGR, 用于将相同时隙上来自不同所述 FTL的时分光突 发信号交换到不同的输出端发送给所述 OR;
每个所述 OR,用于接收所述 AWGR发送的一个输出端上的时分光突 发信号， 并将所述时分光突发信号转换为电时分突发数据单元， 然后发送 给所述发送端电交换单元上与所述 OR连接的输入端口。
18、 根据权利要求 16或 17所述的多框集群的光网络交换节点， 其特 征在于， 每个所述 AWGR 同时接收到相同时隙上的时分光突发信号， 并 将交换到不同输出端的时分光突发信号同时发送给与所述各个输出端连 接的所述 OR。
19、 一种多框集群的光网络交换节点， 其特征在于， 包括权利要求 13 或 14所述的线路框和全光交换单元；
所述全光交换单元包括： 多个输入端和多个输出端； 每个所述接收端 电交换单元的每个输出端口通过所连接的 FTL 分别与所述全光交换单元 的一个输入端相连接， 每个所述发送端电交换单元的每个接收端口通过所 连接的 OR分别与所述全光交换单元的一个输出端相连接；
每个所述接收端电交换单元， 用于通过所述接收端电交换单元的多个 接收端口接收多路数据单元， 对接收到的多路数据单元进行第一级电交 换，并通过所述接收端电交换单元的多个输出端口所连接的 FTL进行电光 转换后输出给所述全光交换单元；
所述全光交换单元， 用于对所述接收端电交换单元输出的多路数据单 元进行全光空分交换后输出给所述发送端电交换单元；
所述发送端电交换单元， 用于通过所述发送端电交换单元的多个接收 端口所连接的 OR对所述全光交换单元输出的多路数据单元进行光电转 换， 然后对光电转换后的多路数据单元进行第二级电交换后通过所述发送 端电交换单元的多个输出端口输出多路数据单元。
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