WO2018137154A1 - 一种无源光网络pon的通信方法、装置和系统 - Google Patents

一种无源光网络pon的通信方法、装置和系统 Download PDF

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Publication number
WO2018137154A1
WO2018137154A1 PCT/CN2017/072512 CN2017072512W WO2018137154A1 WO 2018137154 A1 WO2018137154 A1 WO 2018137154A1 CN 2017072512 W CN2017072512 W CN 2017072512W WO 2018137154 A1 WO2018137154 A1 WO 2018137154A1
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Prior art keywords
wavelength
onu
uplink
olt
downlink
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PCT/CN2017/072512
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English (en)
French (fr)
Inventor
林华枫
刘德坤
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华为技术有限公司
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Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to PCT/CN2017/072512 priority Critical patent/WO2018137154A1/zh
Priority to EP17826125.1A priority patent/EP3382919A4/en
Priority to CN201780004346.0A priority patent/CN108633325A/zh
Priority to TW107102008A priority patent/TW201828621A/zh
Priority to ARP180100146A priority patent/AR110842A1/es
Priority to US15/909,624 priority patent/US20180213307A1/en
Publication of WO2018137154A1 publication Critical patent/WO2018137154A1/zh

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    • 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
    • H04Q11/0067—Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0227—Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H04J14/0228—Wavelength allocation for communications one-to-all, e.g. broadcasting wavelengths
    • H04J14/023—Wavelength allocation for communications one-to-all, e.g. broadcasting wavelengths in WDM passive optical networks [WDM-PON]
    • H04J14/0235—Wavelength allocation for communications one-to-all, e.g. broadcasting wavelengths in WDM passive optical networks [WDM-PON] for upstream transmission
    • H04J14/0236—Wavelength allocation for communications one-to-all, e.g. broadcasting wavelengths in WDM passive optical networks [WDM-PON] for upstream transmission using multiple wavelengths
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0278—WDM optical network architectures
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0278—WDM optical network architectures
    • H04J14/0282—WDM tree architectures
    • 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
    • H04Q2011/0086—Network resource allocation, dimensioning or optimisation
    • 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 application relates to access network communication technologies, and in particular, to a communication method, apparatus, and system for a passive optical network PON.
  • FIG. 1 is a schematic diagram of a PON architecture of the prior art.
  • the PON architecture includes an optical line terminal (OLT) at the central office, an optical distribution network (ODN), and multiple optical network units located at the customer premises (optical).
  • ONT optical line terminal
  • ODN optical distribution network
  • ONU optical network unit
  • the ODN includes a backbone fiber, a split beam splitter (Splitter), and a branch fiber.
  • PON passive optical network
  • IEEE Institute of Electrical and Electronics Engineers
  • 2a is a schematic diagram of a 25Gb/s EPON architecture
  • FIG. 2b is a 50Gb/s EPON architecture diagram
  • each 25G ONU is configured with a pair of uplink and downlink wavelengths ⁇ 1.
  • ⁇ 1 may include a downstream wavelength ⁇ d1 and an upstream wavelength ⁇ u1.
  • 50 Gb/s EPON each 50G ONU is configured with two pairs of uplink and downlink wavelengths ⁇ 1, ⁇ 2.
  • ⁇ 1 may include a downstream wavelength ⁇ d1 and an upstream wavelength ⁇ u1
  • ⁇ 2 may include a downstream wavelength ⁇ d2 and an upstream wavelength ⁇ u2.
  • each 100G ONU is configured with four pairs of uplink and downlink wavelengths ⁇ 1, ⁇ 2, ⁇ 3, ⁇ 4.
  • ⁇ 1 may include a downstream wavelength ⁇ d1 and an upstream wavelength ⁇ u1
  • ⁇ 2 may include a downstream wavelength ⁇ d2 and an upstream wavelength ⁇ u2
  • ⁇ 3 may include a downstream wavelength ⁇ d3 and an upstream wavelength ⁇ u3
  • ⁇ 4 may include a downstream wavelength ⁇ d4 and an upstream wavelength ⁇ u4.
  • ⁇ d1 and ⁇ u1 used by the ONU of the 25G are one pair of uplink and downlink wavelengths in the ONU of 100G.
  • the allowable center wavelength operating range of ⁇ d1, ⁇ u1 used by the 25G ONU is the same as the center wavelength operating range of ⁇ d1, ⁇ u1 used by the 100G ONU, and the center wavelength operating range has a width of +/- 1 nm. Since ⁇ u1 uses a +/-1 nm center wavelength operating range width is relatively narrow, the ONU requires a refrigerating device, resulting in a complicated PON system architecture and high cost.
  • the embodiment of the invention provides a communication method, device and system for a passive optical network PON, which solves the problem of complicated structure and high cost of the PON system.
  • an embodiment of the present invention provides a communication method of a PON of a passive optical network, where the PON includes an optical line terminal OLT and a first optical network unit ONU, and the method includes: the OLT passes A downlink wavelength ⁇ dx is communicated with the first ONU, and the one downlink wavelength ⁇ dx is any one of N downlink wavelengths ⁇ d1 ⁇ dN; the OLT communicates with the first ONU through an uplink wavelength ⁇ u0, The one upstream wavelength ⁇ u0 is different from any one of the M upstream wavelengths ⁇ u1 ⁇ uM; wherein the N downlink wavelengths ⁇ d1 ⁇ ⁇ dN and the M uplink wavelengths ⁇ u1 ⁇ ⁇ uM are wavelength values configured by the second ONU N and M are integers greater than or equal to 2, and x is any one of 1 to M.
  • the first ONU and the second ONU can be deployed in the same PON system.
  • the second ONU may be any one of the ONUs other than the first ONU.
  • the first ONU may be a single upstream wavelength ONU, that is, an ONU having an upstream wavelength.
  • the second ONU may be a multi-upstream wavelength ONU, that is, an ONU having a plurality of upstream wavelengths.
  • the downlink wavelength ⁇ dx of the first ONU may be any one of the N downlink wavelengths of the second ONU, so that the first ONU and the second ONU can share one optical transmitter Tx on the OLT side, which reduces the cost of network deployment.
  • the upstream wavelength ⁇ u0 of the first ONU and the M upstream wavelengths of the second ONU are different, so that the first ONU has a wider wavelength range, thereby eliminating the need for cooling, reducing the manufacturing cost of the ONU, thereby reducing the PON system. Complexity and cost.
  • the operating range of the center wavelength allowed by the one upstream wavelength ⁇ u0 is different from the operating range of the center wavelength allowed by any one of the M upstream wavelengths ⁇ u1 ⁇ uM.
  • the center wavelength operating range allowed for the upstream wavelength ⁇ u0 is from ⁇ u0-10 nm to ⁇ u0+10 nm.
  • the central wavelength operating range allowed by ⁇ u1 to ⁇ uM is from ⁇ u1-1nm to ⁇ u1+1nm.
  • the wavelength width of the upstream wavelength ⁇ u0 and the wavelength width of any one of the N upstream wavelengths ⁇ u1 ⁇ uN may be different.
  • the wavelength width of the upstream wavelength ⁇ u0 may be 20 nm.
  • the wavelength width of any one of the N upstream wavelengths ⁇ u1 ⁇ uN may be narrower than ⁇ u0, for example, +/- 1 nm, or +/- 1.5 nm, or even narrower.
  • the first ONU may have one downlink wavelength or multiple downlink wavelengths.
  • any one of the N downlink wavelengths of the second ONU may be taken as the downlink wavelength of the first ONU.
  • the downlink wavelength of the first ONU may also be selected from the N downlink wavelengths of the second ONU.
  • the first ONU and the second ONU use the same downlink wavelength, so that the first ONU and the second ONU can share the same optical transmitter on the OLT side, which reduces the cost of the OLT.
  • the first ONU may be a symmetric ONU.
  • both the uplink and the downlink have a wavelength of 10G or 25G symmetric ONUs with equal uplink and downlink rates.
  • the first ONU can also be an asymmetric ONU.
  • 25G/10G asymmetric ONUs with one wavelength and one uplink, but with an uplink rate of 10 Gb/s and a downlink rate of 25 Gb/s.
  • the uplink has one wavelength
  • the downlink has a plurality of wavelengths, and each wavelength has a rate of 25 Gb/s of a 100 G/25 G asymmetric ONU.
  • the second ONU may be a symmetric ONU, that is, M is equal to N.
  • the second ONU can also be an asymmetric ONU, for example, M is less than N.
  • the OLT sends a registration message to the first ONU by using the one downlink wavelength ⁇ dx; the OLT receives a registration response message from the first ONU by using the one uplink wavelength ⁇ u0.
  • the communication between the OLT and the ONU may include a registration process. During the registration process, the OLT receives the response message of the first ONU through the uplink wavelength ⁇ u0. In the process, first The ONU does not require cooling and saves costs.
  • the OLT sends a time slot grant message to the first ONU by using the one downlink wavelength ⁇ dx, where the time slot grant message includes an authorization time slot of the one uplink wavelength ⁇ u0;
  • the OLT receives an uplink signal from the first ONU through the grant slot of the one uplink wavelength ⁇ u0.
  • the communication between the OLT and the ONU may include a data transmission process. During data transmission, the OLT receives the uplink signal of the first ONU through the uplink wavelength ⁇ u0. In this process, the first ONU does not require cooling, saving costs.
  • an embodiment of the present invention provides a communication method of a passive optical network PON, where the PON includes an optical line terminal OLT and a first optical network unit ONU, and the method includes: the first ONU passes a downlink wavelength ⁇ dx communicates with the OLT, the one downlink wavelength ⁇ dx is any one of N downlink wavelengths ⁇ d1 ⁇ dN; the first ONU communicates with the OLT through an uplink wavelength ⁇ u0, the one upstream wavelength ⁇ u0 It is different from any one of the M uplink wavelengths ⁇ u1 ⁇ uM; wherein the N downlink wavelengths ⁇ d1 ⁇ ⁇ dN and the M uplink wavelengths ⁇ u1 ⁇ uM are wavelength values configured by the second ONU, and N and M are both For an integer greater than or equal to 2, x is any one of 1 to M.
  • the first ONU and the second ONU can be deployed in the same PON system.
  • the second ONU may be any one of the ONUs other than the first ONU.
  • the first ONU may be a single upstream wavelength ONU, that is, an ONU having an upstream wavelength.
  • the second ONU may be a multi-upstream wavelength ONU, that is, an ONU having a plurality of upstream wavelengths.
  • the downlink wavelength ⁇ dx of the first ONU may be any one of the N downlink wavelengths of the second ONU, so that the first ONU and the second ONU can share one optical transmitter Tx on the OLT side, which reduces the cost of network deployment.
  • the upstream wavelength ⁇ u0 of the first ONU and the M upstream wavelengths of the second ONU are different, so that the first ONU has a wider wavelength range, thereby eliminating the need for cooling, reducing the manufacturing cost of the ONU, thereby reducing the PON system. Complexity and cost.
  • the operating range of the center wavelength allowed by the one upstream wavelength ⁇ u0 is different from the operating range of the center wavelength allowed by any one of the M upstream wavelengths ⁇ u1 ⁇ uM.
  • the center wavelength operating range allowed for the upstream wavelength ⁇ u0 is from ⁇ u0-10 nm to ⁇ u0+10 nm.
  • the central wavelength operating range allowed by ⁇ u1 to ⁇ uM is from ⁇ u1-1nm to ⁇ u1+1nm.
  • the wavelength width of the upstream wavelength ⁇ u0 and the wavelength width of any one of the N upstream wavelengths ⁇ u1 ⁇ uN may be different.
  • the wavelength width of the upstream wavelength ⁇ u0 may be 20 nm.
  • the wavelength width of any one of the N upstream wavelengths ⁇ u1 ⁇ uN may be narrower than ⁇ u0, for example, +/- 1 nm, or +/- 1.5 nm, or even narrower.
  • the first ONU may have one downlink wavelength or multiple downlink wavelengths.
  • any one of the N downlink wavelengths of the second ONU may be taken as the downlink wavelength of the first ONU.
  • the downlink wavelength of the first ONU may also be selected from the N downlink wavelengths of the second ONU.
  • the first ONU and the second ONU use the same downlink wavelength, so that the first ONU and the second ONU can share the same optical transmitter on the OLT side, which reduces the cost of the OLT.
  • the first ONU may be a symmetric ONU.
  • both the uplink and the downlink have a wavelength of 10G or 25G symmetric ONUs with equal uplink and downlink rates.
  • the first ONU can also be asymmetric ONU.
  • 25G/10G asymmetric ONUs with one wavelength and one uplink, but with an uplink rate of 10 Gb/s and a downlink rate of 25 Gb/s.
  • the uplink has one wavelength
  • the downlink has a plurality of wavelengths, and each wavelength has a rate of 25 Gb/s of a 100 G/25 G asymmetric ONU.
  • the second ONU may be a symmetric ONU, that is, M is equal to N.
  • the second ONU can also be an asymmetric ONU, for example, M is less than N.
  • the method includes: the first ONU receiving a registration message from the OLT by using the one downlink wavelength ⁇ dx; the first ONU sending the OLT to the OLT by using the one uplink wavelength ⁇ u0 Send a registration response message.
  • the communication between the OLT and the ONU may include a registration process. During the registration process, the first ONU sends a registration response message to the OLT through the upstream wavelength ⁇ u0. In this process, the first ONU does not require cooling, saving costs.
  • the method includes: receiving, by the first ONU, a time slot grant message from the OLT by using the one downlink wavelength ⁇ dx, where the time slot grant message includes the one uplink wavelength ⁇ u0 Authorizing the time slot; the first ONU sends an uplink signal to the OLT through the authorization time slot of the one uplink wavelength ⁇ u0.
  • the communication between the OLT and the ONU may include a data transmission process. During data transmission, the first ONU sends an uplink signal to the OLT through the uplink wavelength ⁇ u0. In this process, the first ONU does not require cooling, saving costs.
  • an embodiment of the present invention provides an OLT, which is capable of performing the functions of the method steps in the first aspect and any possible implementation manner of the first aspect.
  • the functions may be implemented by hardware or by corresponding software implemented by hardware.
  • the hardware or software includes one or more modules corresponding to the functions described above.
  • the modules can be software and/or hardware.
  • the structure of the OLT includes a light emitter and a light receiver.
  • the transmitter and the optical receiver are configured to support communication between the OLT and the ONU, and the optical transmitter is configured to send information or instructions involved in the foregoing method to the ONU, and the optical receiver is configured to receive information or instructions sent by the ONU.
  • the OLT can also include a memory for coupling with the processor that holds the program instructions and data necessary for the OLT.
  • an embodiment of the present invention provides an ONU capable of performing the functions of the method steps in any one of the possible implementations of the second aspect and the second aspect.
  • the functions may be implemented by hardware or by corresponding software implemented by hardware.
  • the hardware or software includes one or more modules corresponding to the functions described above.
  • the modules can be software and/or hardware.
  • the structure of the ONU includes a light emitter and a light receiver.
  • the transmitter and the optical receiver are configured to support communication between the OLT and the ONU, and the optical transmitter is configured to send information or instructions involved in the foregoing method to the OLT, where the optical receiver is configured to receive information or instructions sent by the OLT.
  • the ONU may also include a memory for coupling with a processor that stores program instructions and data necessary for the ONU.
  • an embodiment of the present invention provides a PON system, where the PON system includes the OLT and the ONU described in the foregoing aspects.
  • Yet another aspect of the present application provides a computer readable storage medium having instructions stored therein that, when executed on a computer, cause the computer to perform the methods described in the above aspects.
  • Yet another aspect of the present application provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the methods described in the various aspects above.
  • FIG. 1 is a schematic structural diagram of a PON of the prior art
  • 2a is a schematic diagram of the architecture of a 25 Gb/s EPON
  • Figure 2b is a schematic diagram of the architecture of a 50 Gb/s EPON
  • 2c is a schematic diagram of the architecture of a 100 Gb/s EPON
  • FIG. 3a is a schematic structural diagram of a PON system 300a according to an embodiment of the present invention.
  • FIG. 3b is a schematic structural diagram of another PON system 300b according to an embodiment of the present invention.
  • FIG. 4a is a schematic structural diagram of an OLT 400a according to an embodiment of the present invention.
  • FIG. 4b is a schematic structural diagram of an OLT 400b according to an embodiment of the present invention.
  • FIG. 5 is a schematic diagram of a wavelength distribution according to an embodiment of the present invention.
  • FIG. 6 is a schematic structural diagram of an ONU 600a according to an embodiment of the present invention.
  • FIG. 6b is a schematic structural diagram of an ONU 600b according to an embodiment of the present invention.
  • FIG. 6c is a schematic structural diagram of an ONU 600c according to an embodiment of the present invention.
  • FIG. 7 is a schematic diagram of signaling interaction of an ONU registration according to an embodiment of the present invention.
  • FIG. 8 is a schematic diagram of interaction of data transmission of an ONU according to an embodiment of the present invention.
  • FIG. 9 is an exemplary flowchart of a method for communicating a passive optical network PON according to an embodiment of the present invention.
  • FIG. 10 is an exemplary flowchart of a method for communicating a passive optical network PON according to an embodiment of the present invention
  • FIG. 11 is a schematic structural diagram of a network device 1100 according to an embodiment of the present invention.
  • an ONU In order to increase the bandwidth of a passive optical network PON system, a PON system supporting multiple wavelengths (or wavelength channels/wavelength channels) has been proposed, for example, 50G EPON and 100G EPON mentioned in the background art.
  • an ONU In a PON system, an ONU can be configured with multiple pairs of upstream and downstream wavelengths (two pairs and above). It can also be configured with a pair of uplink and downlink wavelengths. The number of wavelengths is different and the rate of the ONU can be different.
  • an ONU having a pair of uplink and downlink wavelengths may include an ONU having an uplink and downlink rate of 10G or 25G, and an ONU having multiple pairs of uplink and downlink wavelengths may include an ONU having an uplink and downlink rate of 100G or 50G.
  • the uplink and downlink rates may be the same, and the number of uplink and downlink wavelengths may also be the same, which is called a symmetric ONU.
  • the traffic of the uplink and downlink services may be different.
  • the downlink traffic is usually far greater than the uplink traffic. Therefore, the uplink and downlink rates of the same ONU can be Different, for example, the downlink rate on ⁇ d1 may be 25Gb/s, and the corresponding uplink rate may be 10Gb/s, and such ONU constitutes a 25G/10G asymmetric ONU.
  • the number of downlink wavelengths and the number of uplink wavelengths of the ONU may be different.
  • an ONU may have four downlink wavelengths ⁇ d1, ⁇ d2, ⁇ d3, and ⁇ d4, and only one uplink wavelength ⁇ u1, each wavelength rate is 25 Gb/s,
  • An asymmetric ONU constituting 100G/25G; or two upstream wavelengths ⁇ u1 and ⁇ u2 on the upstream form a 100G/50G asymmetric ONU.
  • the single uplink wavelength ONU in the embodiment of the present invention may include an ONU having only one wavelength of uplink and downlink wavelengths, and may also include an ONU having one uplink wavelength and multiple downlink wavelengths.
  • the multi-uplink wavelength ONU may include an ONU having multiple wavelengths on the uplink and downlink wavelengths, or an ONU having multiple uplink wavelengths and one downlink wavelength.
  • an ONU having an upstream wavelength of only one wavelength whether it is a symmetric ONU or an asymmetric ONU, may be a single upstream wavelength ONU as described in the embodiment of the present invention.
  • multiple uplink wavelength ONUs and single upstream wavelength ONUs can be deployed in the same PON system to share network devices such as ODNs to save network upgrade costs.
  • the embodiment of the invention can be applied to a PON system in which multiple uplink wavelength ONUs and single uplink wavelength ONUs coexist, and the manufacturing cost of the single uplink wavelength ONU can be saved.
  • the embodiments of the present invention can be applied to multiple PON systems, for example, an Asynchronous Transfer Mode (PON) (PON), a Broadband PON (BPON), an Ethernet PON (EPON), and 10 Gigabit.
  • PON Asynchronous Transfer Mode
  • BPON Broadband PON
  • EPON Ethernet PON
  • 10 Gigabit 10 Gigabit
  • EPON (10gigabite-EPON, 10G-EPON), gigabit-capable PON (GPON), XGPON, wavelength division multiplexing (PON), WDM-PON, time division wavelength division multiplexing (PON)
  • PON wavelength division multiplexing
  • WDM-PON WDM-PON
  • PON time division wavelength division multiplexing
  • TWDM-PON can also be applied to a next generation PON (NGPON) system, NG-PON2, and the like.
  • FIG. 3 is a schematic structural diagram of a PON system 300a according to an embodiment of the present invention.
  • the PON system 300a includes at least one OLT 301, a plurality of ONUs 303, and an ODN 305.
  • the OLT 301 is connected to the plurality of ONUs 303 in a point-to-multipoint manner via the ODN 305.
  • the direction from the OLT 301 to the ONU 303 may be a downlink direction, and the direction from the ONU 303 to the OLT 301 may be an uplink direction.
  • the OLT 301 can transmit a downlink wavelength signal to the ONU 303; in the uplink direction, the ONU 303 can transmit an uplink wavelength signal to the OLT 301.
  • the wavelength signal can be an optical signal carrier having a certain wavelength for carrying data, information or messages, and the like.
  • the plurality of ONUs 303 may include at least one single upstream wavelength ONU, such as an ONU of 25G, and may also include at least one multi-upstream wavelength ONU, such as an ONU of 100G.
  • at least one other rate ONU such as a 50G ONU, may also be included in the multiple ONUs 303.
  • a single upstream wavelength ONU uses a pair of uplink and downlink wavelengths.
  • the 25G ONU uses the downstream wavelength ⁇ d1 and the upstream wavelength ⁇ u0.
  • Multiple upstream wavelength ONUs use two or more pairs of upstream and downstream wavelengths.
  • the 50G ONU uses the downstream wavelengths ⁇ d1 and ⁇ d2, and the upstream wavelengths ⁇ u1 and ⁇ u2.
  • the ONUs of 100G use the downstream wavelengths ⁇ d1, ⁇ d2, ⁇ d3, and ⁇ d4, and the upstream wavelengths ⁇ u1, ⁇ u2, ⁇ u3, and ⁇ u4.
  • FIG. 3b is a schematic structural diagram of another PON system 300b according to an embodiment of the present invention.
  • the PON system 300b may also include a single upstream wavelength ONU of other rates, such as an ONU of 10G.
  • the PON system 300b may further include an asymmetric single uplink wavelength ONU, such as an asymmetric ONU of 25G/10G or an asymmetric ONU of 100G/25G.
  • the 25G ONU and the 10G ONU can use the same upstream wavelength ⁇ u0.
  • the 25G ONU and the 10G ONU can use different downstream wavelengths.
  • a 10G ONU uses a downstream wavelength ⁇ d0
  • an ONU of 25G uses a downstream wavelength ⁇ d1.
  • the same downstream wavelength can be used for the 25G ONU and the 10G ONU.
  • the OLT 301 is typically located at a central location, such as a central office (CO).
  • the OLT 301 can serve as a transmission medium between the ONU 303 and an upper layer network (not shown), and forwards the signal received from the upper layer network to the ONU 303 as a downlink signal, or forwards the uplink signal received from the ONU 303 to Upper network.
  • FIG. 4 is a schematic structural diagram of an OLT 400a according to an embodiment of the present invention.
  • the OLT 301 in Fig. 3a can refer to the structure of the OLT 400a.
  • the OLT 400a may include optical transmitters Tx1 - Tx4 401, optical receivers Rx0 - Rx4 403, a multiplexer 405, an optical coupler 407, and a demultiplexer 409.
  • the light emitters Tx1 to Tx4 401 are used to generate a downstream wavelength signal. For example, four downlink wavelength signals ⁇ d1, ⁇ d2, ⁇ d3, ⁇ d4 are shown.
  • the four downstream wavelength signals are combined into one optical signal after passing through the multiplexer 405, and are sent to the ODN 305 through the optical coupler 407.
  • the optical receivers Rx0 to Rx4 403 are for receiving uplink wavelength signals. For example, five uplink wavelength signals ⁇ u0, ⁇ u1, ⁇ u2, ⁇ u3, and ⁇ u4 are shown.
  • the upstream wavelength signals ⁇ u0, ⁇ u1, ⁇ u2, ⁇ u3, and ⁇ u4 are split into two paths after passing through the optical coupler 407. One path includes ⁇ u0 and is received by Rx0, and the other path includes ⁇ u1, ⁇ u2, ⁇ u3, and ⁇ u4, which are respectively received by Rx1 to Rx4.
  • a preamplifier such as a semiconductor optical amplifier (SOA) 411
  • SOA semiconductor optical amplifier
  • the upstream wavelength signals ⁇ u1, ⁇ u2, ⁇ u3, ⁇ u4 are split by the optical demultiplexer 409; then enter the SOA 411 for optical power amplification; then pass through the narrowband filter 413 to filter out the spontaneous radiated optical signals other than the effective optical signals; Enter the optical receiver Rx, such as avalanche photodiode (APD).
  • the sensitivity gain provided by the preamplifier is usually determined by its gain noise figure.
  • the narrow-band filter can filter out the noise outside the signal band well, which can effectively increase the gain brought by the amplifier. For example, when there is no narrow-band filter, the amplifier can only provide 1.3dB of gain, and after adding a narrow-band filter, the amplifier can provide 4.3dB of gain, and the sensitivity can be significantly improved.
  • FIG. 4b is a schematic structural diagram of an OLT 400b according to an embodiment of the present invention.
  • the OLT 301 in Fig. 3b can refer to the structure of the OLT 400b.
  • the OLT 400b of Figure 4b differs from the OLT 400a of Figure 4a in that the OLT 400b of Figure 4b has a 10G optical transmitter Tx0 for generating a downstream wavelength signal ⁇ d0 for the 10G ONU.
  • the OLT 400b can receive the upstream wavelength signal ⁇ u0 from the 25G ONU and the 10G ONU through the same optical receiver 10G/25G Dual Rx0.
  • the 25G ONU can share an upstream wavelength ⁇ u0 with the 10G ONU, and the OLT can use the same optical receiver Rx0 to receive the upstream wavelength of the 10G ONU and the 25G ONU.
  • the signal ⁇ u0 saves the cost of network upgrades.
  • the wavelength signal needs to be distributed over a narrow range, which facilitates filtering of the narrowband filter after the preamplifier.
  • the OLT receives the upstream wavelength signal from the ONU, in order to enable the preamplifier on the OLT side to provide sufficient gain to meet the power requirement, ONU
  • the width of the central wavelength operating range allowed for the upstream wavelength (which may be referred to simply as "wavelength width") may typically be +/- 1 nm or +/- 1.5 nm, or even a narrower width.
  • FIG. 5 is a schematic diagram of a wavelength distribution provided by an embodiment of the present invention. As shown in FIG.
  • ⁇ d1 of the four downstream wavelengths ⁇ d1 to ⁇ d4 of the 100G ONU can be configured as the downstream wavelength, and an upstream wavelength ⁇ u0 of a wider wavelength width is arranged.
  • the wavelength width of ⁇ u1 ⁇ 4 may be +/- 1 nm or +/- 1.5 nm, or between +/- 1 nm and +/- 1.5 nm, or less than +/- 1 nm.
  • the wavelength width of ⁇ u0 is larger than the wavelength width of any one of ⁇ u1 ⁇ 4, such as +/- 10 nm.
  • Table 1 shows an example of the operating range of the center wavelength allowed for the downstream wavelengths ⁇ d1 to ⁇ d4 and the upstream wavelengths ⁇ u0 to ⁇ u4.
  • the operating range of the center wavelength allowed by ⁇ u0 may be different from the operating range of the center wavelength allowed by any of the four upstream wavelengths ⁇ u1 ⁇ u4 in the 100G ONU.
  • the wavelength width of ⁇ u0 may be different from the wavelength width of any of ⁇ u1 to ⁇ u4.
  • the center wavelength of ⁇ u1 is 1289.71 nm
  • the center wavelength operating range allowed by ⁇ u1 is 1288.71 nm to 1129.71 nm
  • the wavelength width is 2 nm.
  • the center wavelength of ⁇ u2 is 1394.16 nm, and the center wavelength allowed for ⁇ u2 is from 1393.16 nm to 1295.16 nm, and the wavelength width is 2 nm.
  • the center wavelength of ⁇ u3 is 1296.65 nm, and the center wavelength allowed for ⁇ u3 is from 1297.65 nm to 1299.65 nm, and the wavelength width is 2 nm.
  • the center wavelength of ⁇ u4 is 1303.16 nm, and the center wavelength allowed for ⁇ u4 is 1302.16 nm to 1304.16 nm, and the wavelength width is 2 nm.
  • the center wavelength of ⁇ u0 is 1270 nm, and the center wavelength allowed for ⁇ u0 is from 1260 nm to 1280 nm, and the wavelength width is 20 nm.
  • Wavelength value Wavelength working range (range/band) ⁇ d1 1334.78 ⁇ 1nm ⁇ d2 1349.20 ⁇ 1nm ⁇ d3 1354.08 ⁇ 1nm ⁇ d4 1358.99 ⁇ 1nm ⁇ u1 1289.71 ⁇ 1nm ⁇ u2 1294.16 ⁇ 1nm ⁇ u3 1298.65 ⁇ 1nm ⁇ u4 1303.16 ⁇ 1nm ⁇ u0 1270 ⁇ 10nm
  • the ONU 303 can be distributed in a user-side location, such as a customer premises.
  • the ONU 303 can serve as a medium between the OLT 301 and the user equipment.
  • the ONU 303 can forward the downlink signal received from the OLT 301 to the user equipment, or forward the signal received from the user equipment to the OLT 301 as an uplink signal.
  • the user equipment may include terminal devices such as a personal computer (PC), a portable electronic device, and the like. It should be understood that the structure of the ONU 303 is similar to that of an optical network terminal (ONT). Therefore, in the embodiment of the present invention, the ONU and the ONT can be interchanged.
  • ONT optical network terminal
  • FIG. 6 is a schematic structural diagram of an ONU 600a according to an embodiment of the present invention.
  • ONU 600a can It is a 25G ONU.
  • the ONU 600a may include an optical receiver Rx1 601, a light emitter Tx0 603, and a WDM 605.
  • the optical transmitter Rx1 601 is configured to receive a downlink wavelength signal ⁇ d1 from the OLT, and the optical transmitter Tx0 603 is configured to send an uplink wavelength signal ⁇ u0 to the OLT.
  • the WDM 605 is used for wavelength division multiplexing of the upstream wavelength signal and the uplink wavelength signal.
  • FIG. 6b is a schematic structural diagram of an ONU 600b according to an embodiment of the present invention.
  • the ONU 600b can be a 100G ONU.
  • the ONU 600b may include optical receivers Rx1 to Rx4 601, optical transmitters Tx1 to Tx4 603, WDM 605, and an optical multiplexer 607.
  • the optical transmitters Rx1 to Rx4 601 are for receiving downlink wavelength signals ⁇ d1 to ⁇ d4 from the OLT, respectively, and the optical transmitters Tx1 to Tx4 603 are for transmitting uplink wavelength signals ⁇ u1 to ⁇ u4 to the OLT.
  • the WDM 605 is used to wavelength division multiplex each pair of upstream wavelength signals and upstream wavelength signals.
  • the optical multiplexer 607 divides the downlink wavelength signals ⁇ d1 to ⁇ d4 and combines the upstream wavelength signals ⁇ u1 to ⁇ u4.
  • FIG. 6c is a schematic structural diagram of an ONU 600c according to an embodiment of the present invention.
  • the ONU 600c can also be a 100G ONU.
  • the difference between Fig. 6c and Fig. 6b is that the WDM 605 and the optical multiplexer 607 are arranged at different positions.
  • the 10G ONU is similar to the 25G ONU.
  • the difference is that the downstream wavelength of the 10G ONU can be different from the downstream wavelength ⁇ d1 used by the 25G ONU, and the line rate of the wavelength is different.
  • the ONU of the 50G is similar to the ONU of the 100G.
  • the difference is that the optical receiver includes Rx1 and Rx2, and the optical transmitter includes Tx1 and Tx2, which are not described here.
  • the downstream wavelength ⁇ d1 of the 25G ONU may be one of the downstream wavelengths of the 50G ONU or the 100G ONU.
  • different ONUs can use different time slots on the wavelength in a time division multiplexed manner.
  • a 25G ONU and a 100G ONU use different time slots on the downlink wavelength ⁇ d1 in a time division multiplex manner.
  • the same ONU can also be configured with multiple different wavelengths, or different ONUs can be configured with different wavelengths.
  • the same ONU or different ONUs can use different wavelengths by wavelength division multiplexing.
  • a 100G ONU can use four different downlink wavelengths ⁇ d1 ⁇ d4 or four different upstream wavelengths ⁇ u1 ⁇ 4 by wavelength division multiplexing.
  • the 25G ONU and the 100G ONU can be used by wavelength division multiplexing.
  • the PON system 300 can implement the ODN 305 between the OLT 301 and the ONU 303 without any active devices.
  • the ODN 305 may include a passive optical device such as a passive splitter or a multiplexer, an optical fiber, or the like.
  • the ODN 305 can use a splitter with a split ratio of 1:4, 1:8, 1:6, 1:32 or 1:64.
  • the figure shows a 1:4 Splitter, including a common port and four branch ports.
  • the splitter is connected to the backbone fiber through the public port and the OLT 301.
  • the splitter is connected to the four ONUs 303 through four branch ports and branch fibers.
  • the ODN 305 can further increase the split ratio by two or more beamsplitters.
  • one wavelength different from any one of multiple uplink wavelengths of the multiple uplink wavelength ONUs is configured as an uplink wavelength of a single uplink wavelength ONU.
  • the upstream wavelength of the single upstream wavelength ONU has a wider central wavelength operating range without refrigeration, which reduces the complexity and cost of the PON system.
  • the communication between the OLT and the ONU may include ONU online registration and ONU data transmission.
  • the OLT sends a downlink wavelength signal to the ONU
  • the ONU sends an uplink wavelength signal to the OLT. Therefore, the upstream wavelength and the downstream wavelength need to be configured on the OLT and the ONU, respectively.
  • the wavelength configuration can be configured directly on the optical transmitter and optical receiver of the OLT and ONU. For example, the emission wavelength of the laser or the reception wavelength of the APD is adjusted to a certain wavelength value in the OLT or the ONU.
  • the wavelength configuration mode can also be dynamically configured through the network management or OLT. For example, the OLT dynamically configures a certain wavelength value to the emission wavelength of the ONU laser or the reception wavelength of the APD.
  • FIG. 7 is a schematic diagram of signaling interaction of an ONU registration according to an embodiment of the present invention.
  • a 25G ONU is taken as an example, as shown in Figure 7.
  • the OLT periodically generates a legal discovery time window on the broadcast channel of the downlink wavelength ⁇ d1, for example, generates a discovery time window by using a Gate message.
  • the Gate message can include the time and length of the discovery window.
  • the ONUs of 702 and 25G are received by the optical receiver, and when the period of the discovery time window in the Gate message starts, the registration request message is sent on the uplink wavelength ⁇ u0.
  • the registration request message may be a Register_REQ message.
  • the OLT After receiving the registration request message of the ONU, the OLT allocates a Logical Link Identifier (LLID) of the ONU to the ONU, and sends a Register message to the ONU at the downlink wavelength ⁇ d1 for completing the ranging.
  • the Register message may include information such as the LLID of the ONU and the synchronization time required by the OLT.
  • the OLT sends a time slot authorization message, such as a Gate message, to the ONU at the downlink wavelength ⁇ d1.
  • the time slot grant message includes an authorized time slot of the uplink wavelength ⁇ u0, that is, an authorized time slot that allows the ONU to send a registration response message at the uplink wavelength ⁇ u0.
  • the time slot authorization message may also be carried in a Register message sent by the OLT to the ONU.
  • the ONU After receiving the Register message, the ONU returns a registration response message in the grant slot of the uplink wavelength ⁇ u0 in the slot grant message.
  • the registration response message can be a Register_ACK message.
  • the OLT After receiving the registration response message, the OLT can complete the ranging and calculate the distance from the ONU to the OLT or the time required to transmit information between the ONU and the OLT.
  • the ranging may also be implemented by a Gate message of 701 and a Register_REQ message of 702. That is, the ranging can be completed after 702 or after 705.
  • an ONU of 100G is taken as an example for description.
  • the signaling interaction process of the 100G ONU registration is similar to that of the 25G ONU. See also Figure 7.
  • the OLT periodically generates a legal discovery time window on a broadcast channel of one or more downlink wavelengths (eg, one or more of downlink wavelengths ⁇ d1 ⁇ d4), for example, generating a discovery time window by using a Gate message.
  • the Gate message can include the time and length of the discovery window.
  • the 702, 100G ONU receives the Gate message through the optical receiver, and when the period of the discovery time window in the Gate message starts, one or more upstream wavelengths (for example, the upstream wavelength) One or more of ⁇ u1 to ⁇ u4) send registration to the OLT Ask for news.
  • the registration request message may be a Register_REQ message.
  • the registration request message may include wavelength information of the ONU, such as the number of wavelength channels in the uplink and downlink, the wavelength channel, and the like.
  • the upstream wavelength channel may include four upstream wavelengths ⁇ u1 ⁇ u4, and the downstream wavelength channel may include four downstream wavelengths ⁇ d1 ⁇ d4.
  • the OLT After receiving the registration request message of the ONU, the OLT allocates the LLID of the ONU and the channel identifier of each wavelength channel to the ONU.
  • the OLT sends a Register message on each of the downstream wavelength channels (eg, the downstream wavelengths ⁇ d1 ⁇ ⁇ d4) for completing the ranging of each wavelength channel.
  • the Register message may include information such as the LLID of the ONU and the synchronization time required by the OLT.
  • the OLT sends a time slot grant message on each downlink wavelength channel (eg, downlink wavelengths ⁇ d1 ⁇ d4).
  • the time slot grant message includes an authorized time slot of each uplink wavelength (for example, downlink wavelengths ⁇ u1 ⁇ 4), that is, an authorized time slot that allows the ONU to transmit a registration response message at the uplink wavelengths ⁇ u1 ⁇ u4.
  • the OLT transmits a slot grant message containing an grant slot of the uplink wavelength ⁇ u1 on the downlink wavelength ⁇ d1, a slot grant message containing the grant slot of the uplink wavelength ⁇ u2 on the downlink wavelength ⁇ d2, and so on.
  • the time slot authorization message may also be carried in a Register message sent by the OLT to the ONU.
  • the ONU After receiving the Register message, the ONU returns a registration response message in the grant slot of the uplink wavelengths ⁇ u1 ⁇ 4 in the slot grant message.
  • the registration response message can be a Register_ACK message.
  • the OLT After receiving the registration response message, the OLT can complete the ranging and calculate the distance from the ONU to the OLT or the time required to transmit information between the ONU and the OLT.
  • the ranging may also be implemented by a Gate message of 701 and a Register_REQ message of 702. That is, the ranging can be completed after 702 or after 705.
  • FIG. 8 is a schematic diagram of interaction of data transmission of an ONU according to an embodiment of the present invention. After the registration is completed, data can be transferred between the ONU and the OLT. For the data transmission process of a single upstream wavelength ONU, a 25G ONU is taken as an example, as shown in FIG. 8.
  • the OLT sends a time slot grant message to the 25G ONU on the downlink wavelength ⁇ d1, where the time slot grant message may include an authorized time slot of the 25G ONU at the uplink wavelength ⁇ u0.
  • the grant slot of the upstream wavelength ⁇ u0 that is, the slot that allows the 25G ONU to transmit the uplink signal.
  • the 802, 25G ONU sends an uplink signal to the OLT through the uplink wavelength ⁇ u0 in the grant slot of the uplink wavelength ⁇ u0 included in the slot grant message.
  • an ONU of 100 G is taken as an example for description.
  • the 100G ONU data transmission interaction process is similar to the 25G ONU. See also Figure 8.
  • the OLT sends a first time slot grant message to the 100G ONU on the downlink wavelength ⁇ d1, where the first time slot grant message may include an authorized time slot of the 100G ONU at the uplink wavelength ⁇ u1.
  • the OLT sends a second time slot grant message to the 100G ONU on the downlink wavelength ⁇ d2, where the second time slot grant message may include an authorized time slot of the 100G ONU at the uplink wavelength ⁇ u2.
  • the OLT sends a third time slot grant message to the 100G ONU on the downlink wavelength ⁇ d3, wherein the third time slot grant message may include an authorized time slot of the 100G ONU at the uplink wavelength ⁇ u3.
  • the OLT sends a time slot grant message to the 100G ONU on the downlink wavelength ⁇ d4, where the time slot grant message may include an authorized time slot of the 100G ONU at the uplink wavelength ⁇ u4.
  • the OLT When the OLT performs uplink time slot authorization, it needs to perform unified scheduling calculation on multiple wavelength channels, and allocate different time slots to ONUs using the same wavelength. For each upstream wavelength, the time that the uplink signals sent by different ONUs on the same wavelength arrive at the OLT optical receiver cannot overlap each other to avoid collision. For example, an ONU of 100G and an ONU of 50G have the same upstream wavelengths ⁇ u1, ⁇ u2, and an ONU of 100G and an ONU of 50G use different time slots in a time division multiplexing manner on the upstream wavelength ⁇ u1 or ⁇ u2.
  • the 802, 100G ONU sends an uplink signal to the OLT through the uplink wavelength ⁇ u1 in the grant slot of the uplink wavelength ⁇ u1 included in the slot grant message.
  • the 100G ONU sends an uplink signal to the OLT through the uplink wavelength ⁇ u2 in the grant slot of the uplink wavelength ⁇ u2 included in the slot grant message.
  • the 100G ONU transmits an uplink signal to the OLT through the uplink wavelength ⁇ u3 in the grant slot of the uplink wavelength ⁇ u3 included in the slot grant message.
  • the 100G ONU sends an uplink signal to the OLT through the uplink wavelength ⁇ u4 in the grant slot of the uplink wavelength ⁇ u4 included in the slot grant message.
  • FIG. 9 is an exemplary flowchart of a method for communicating a passive optical network PON according to an embodiment of the present invention.
  • the PON includes an optical line terminal OLT and a first optical network unit ONU, and includes the following steps:
  • the OLT communicates with the first ONU by using a downlink wavelength ⁇ dx, where the one downlink wavelength ⁇ dx is any one of N downlink wavelengths ⁇ d1 ⁇ dN;
  • the OLT communicates with the first ONU by using an uplink wavelength ⁇ u0, where the one uplink wavelength ⁇ u0 is different from any one of the M uplink wavelengths ⁇ u1 ⁇ uM.
  • the N downlink wavelengths ⁇ d1 to ⁇ dN and the M uplink wavelengths ⁇ u1 ⁇ uM are wavelength values of the second ONU, and N and M are integers greater than or equal to 2, and x is any one of 1 to M. A value.
  • the operating range of the center wavelength allowed by the one upstream wavelength ⁇ u0 is different from the operating range of the center wavelength allowed by any one of the M upstream wavelengths ⁇ u1 ⁇ uM.
  • the wavelength width of the upstream wavelength ⁇ u0 and the wavelength width of any one of the N upstream wavelengths ⁇ u1 ⁇ uN may be different.
  • the communication process between the OLT and the ONU may include a registration process and a data transfer process.
  • the OLT sends a registration message to the first ONU by using the one downlink wavelength ⁇ dx; the OLT receives a registration response message from the first ONU by using the one uplink wavelength ⁇ u0.
  • the OLT sends a time slot grant message to the first ONU by using the one downlink wavelength ⁇ dx, where the time slot grant message includes an authorization time slot of the one uplink wavelength ⁇ u0;
  • An grant slot of an upstream wavelength ⁇ u0 receives an uplink signal from the first ONU.
  • any one of the optical transmitters Tx1 to Tx4 is configured to communicate with the first ONU through a downlink wavelength ⁇ dx, which is any one of N downlink wavelengths ⁇ d1 ⁇ dN; the optical receiver And Rx0, configured to communicate with the first ONU by using an uplink wavelength ⁇ u0, where the one uplink wavelength ⁇ u0 is different from any one of the M uplink wavelengths ⁇ u1 ⁇ uM; wherein the N downlink wavelengths ⁇ d1 ⁇ ⁇ dN and the M upstream wavelengths ⁇ u1 to ⁇ uM are wavelength values of the second ONU, and N and M are integers greater than or equal to 2, and x is any one of 1 to M.
  • the operating range of the center wavelength allowed by the one upstream wavelength ⁇ u0 is different from the operating range of the center wavelength allowed by any one of the M upstream wavelengths ⁇ u1 ⁇ uM.
  • uplink The wavelength width of the wavelength ⁇ u0 and the wavelength width of any one of the N upstream wavelengths ⁇ u1 to ⁇ uN may be different.
  • the communication process between the OLT and the ONU may include a registration process and a data transfer process.
  • any one of the optical transmitters Tx1 to Tx4 sends a registration message to the first ONU by using the one downlink wavelength ⁇ dx; and the optical receiver Rx0 receives the first ONU by using the one uplink wavelength ⁇ u0 Registration response message.
  • any one of the optical transmitters Tx1 to Tx4 sends a time slot grant message to the first ONU by using the one downlink wavelength ⁇ dx, where the time slot grant message includes the one authorized time slot of the uplink wavelength ⁇ u0
  • the optical receiver Rx0 receives the uplink signal from the first ONU through the grant time slot of the one uplink wavelength ⁇ u0.
  • the downlink wavelength of the first ONU is any one of the downlink wavelengths of the second ONU, and the first ONU and the second ONU may share one optical transmitter on the OLT side.
  • the upstream wavelength of the first ONU is different from any one of the upstream wavelengths of the second ONU, so that the first ONU does not need to be cooled, which reduces the complexity and cost of the PON system.
  • FIG. 10 is an exemplary flowchart of a communication method of a passive optical network PON according to an embodiment of the present invention.
  • the PON includes an optical line terminal OLT and a first optical network unit ONU, and includes the following steps:
  • the first ONU communicates with the OLT through a downlink wavelength ⁇ dx, and the one downlink wavelength ⁇ dx is any one of N downlink wavelengths ⁇ d1 ⁇ dN;
  • the first ONU communicates with the OLT by using an uplink wavelength ⁇ u0, where the one uplink wavelength ⁇ u0 is different from any one of the M uplink wavelengths ⁇ u1 ⁇ uM.
  • the N downlink wavelengths ⁇ d1 to ⁇ dN and the M uplink wavelengths ⁇ u1 ⁇ uM are wavelength values of the second ONU, and N and M are integers greater than or equal to 2, and x is any one of 1 to M. A value.
  • the operating range of the center wavelength allowed by the one upstream wavelength ⁇ u0 is different from the operating range of the center wavelength allowed by any one of the M upstream wavelengths ⁇ u1 ⁇ uM.
  • the wavelength width of the upstream wavelength ⁇ u0 and the wavelength width of any one of the N upstream wavelengths ⁇ u1 ⁇ uN may be different.
  • the first ONU receives a registration message from the OLT by using the one downlink wavelength ⁇ dx; the first ONU sends a registration response message to the OLT by using the one uplink wavelength ⁇ u0.
  • the first ONU receives a time slot grant message from the OLT by using the one downlink wavelength ⁇ dx, where the time slot grant message includes an authorization time slot of the one uplink wavelength ⁇ u0; the first ONU The uplink signal is sent to the OLT by the grant time slot of the one uplink wavelength ⁇ u0.
  • the method steps shown in Figure 10 can be performed by the ONU shown in Figure 6a.
  • the optical receiver Rx1 is configured to communicate with the OLT through a downlink wavelength ⁇ dx, which is any one of N downlink wavelengths ⁇ d1 ⁇ dN; and the optical transmitter Tx0 is used to pass an uplink
  • the wavelength ⁇ u0 is communicated with the OLT, and the one upstream wavelength ⁇ u0 is different from any of the M upstream wavelengths ⁇ u1 ⁇ uM.
  • the N downlink wavelengths ⁇ d1 ⁇ ⁇ dN and the M uplink wavelengths ⁇ u1 ⁇ uM are wavelength values configured by the second ONU, and N and M are integers greater than or equal to 2, x is any one of 1 to M.
  • the operating range of the center wavelength allowed by the one upstream wavelength ⁇ u0 is different from the operating range of the center wavelength allowed by any one of the M upstream wavelengths ⁇ u1 ⁇ uM.
  • the wavelength width of the upstream wavelength ⁇ u0 and the wavelength width of any one of the N upstream wavelengths ⁇ u1 ⁇ uN may be different.
  • the optical receiver Rx1 is configured to receive a registration message from the OLT by using the one downlink wavelength ⁇ dx
  • the optical transmitter Tx0 is configured to send a registration response message to the OLT by using the one uplink wavelength ⁇ u0.
  • the optical receiver Rx1 is configured to receive, by using the one downlink wavelength ⁇ dx, a time slot grant message from the OLT, where the time slot grant message includes an authorized time slot of the one uplink wavelength ⁇ u0; Tx0 is configured to send an uplink signal to the OLT by using an authorization time slot of the one uplink wavelength ⁇ u0.
  • the downlink wavelength of the first ONU is any one of the downlink wavelengths of the second ONU, and the first ONU and the second ONU may share one optical transmitter on the OLT side.
  • the upstream wavelength of the first ONU is different from any one of the upstream wavelengths of the second ONU, so that the first ONU does not need to be cooled, which reduces the complexity and cost of the PON system.
  • the embodiment of the present invention provides a PON system, including an OLT, a first ONU, and a second ONU.
  • the first ONU is configured with a downlink wavelength ⁇ dx and an uplink wavelength ⁇ u0
  • the second ONU is configured with N downlink wavelengths ⁇ d1.
  • the OLT has the structure shown in Fig. 4a or Fig. 4b, and the method steps shown in Fig. 9 are performed.
  • the first ONU may have the structure shown in FIG. 6a, and the method steps shown in FIG. 10 are performed.
  • the second ONU may have a structure as shown in FIG. 6b or 6c.
  • FIG. 11 is a schematic structural diagram of a network device 1100 according to an embodiment of the present invention.
  • the network device 1100 includes a processor 1101, a memory 1102, and a transceiver 1003.
  • the transceiver 1103 may further include a medium access control (MAC) 1104.
  • MAC medium access control
  • Network device 1100 can also include WDM 1105 and communication interface 1106. Any one of the OLTs or ONUs in the above embodiments may have a structure similar to that of the network device 1100.
  • the processor 1101 may be a general-purpose central processing unit (CPU), a microprocessor, an application specific integrated circuit (ASIC), or at least one integrated circuit for executing related programs to implement the present invention.
  • CPU central processing unit
  • ASIC application specific integrated circuit
  • the memory 1102 can be a read only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM).
  • the memory 1102 can store an operating system and other applications.
  • the program code for implementing the technical solution provided by the embodiment of the present invention is stored in the memory 1102 and executed by the processor 1101.
  • the transceiver 1103 can include a light emitter and/or a light receiver.
  • An optical transmitter can be used to transmit signals and an optical receiver can be used to receive signals.
  • the light emitter can be realized by a light emitting device such as a gas laser, a solid laser, a liquid laser, a semiconductor laser or the like.
  • the light receiver can pass the photodetector, for example Such as photoelectric detectors or photodiodes.
  • Transceiver 1103 can be coupled to WDM 1105, which acts as a multiplexer when transmitting signals to communication interface 1106, and WDM 1105 acts as a demultiplexer when receiving signals from communication interface 1106.
  • WDM 1105 can also be referred to as an optocoupler.
  • Communication interface 1106 can be coupled to the ODN.
  • the transceiver 1103 of the network device 1100 communicates with the first ONU through a downlink wavelength ⁇ dx, and the one downlink wavelength ⁇ dx is any one of N downlink wavelengths ⁇ d1 ⁇ dN;
  • An upstream wavelength ⁇ u0 is communicated with the first ONU, and the one upstream wavelength ⁇ u0 is different from any one of the M upstream wavelengths ⁇ u1 ⁇ uM; wherein the N downlink wavelengths ⁇ d1 ⁇ dN and the M
  • the uplink wavelengths ⁇ u1 to ⁇ uM are wavelength values of the second ONU, and N and M are integers greater than or equal to 2, and x is any one of 1 to M.
  • the above functions may be performed under the control of the processor 1101.
  • the processor 1101 executes code stored in the memory 1102 to implement the functions described above.
  • the transceiver 1103 of the network device 1100 communicates with the OLT through a downlink wavelength ⁇ dx, and the one downlink wavelength ⁇ dx is any one of N downlink wavelengths ⁇ d1 ⁇ dN;
  • the wavelength ⁇ u0 is communicated with the OLT, and the one uplink wavelength ⁇ u0 is different from any one of the M uplink wavelengths ⁇ u1 ⁇ uM;
  • the N downlink wavelengths ⁇ d1 ⁇ ⁇ dN and the M uplink wavelengths ⁇ u1 ⁇ uM is a wavelength value of the second ONU, and N and M are integers greater than or equal to 2, and x is any one of 1 to M.
  • the above functions may be performed under the control of the processor 1101.
  • the processor 1101 executes code stored in the memory 1102 to implement the functions described above.
  • the method steps shown in FIG. 9 or FIG. 10 can be implemented by the network device 1100 shown in FIG.
  • the network device 1100 shown in FIG. 11 only shows the processor 1101, the memory 1102, the transceiver 1103, the MAC 1104, the WDM 1105, and the communication interface 1106, in a specific implementation process, those skilled in the art should It is understood that the network device 1100 also contains other devices necessary to achieve normal operation. At the same time, those skilled in the art will appreciate that the network device 1100 may also include hardware devices that implement other additional functions, depending on the particular needs. Moreover, those skilled in the art will appreciate that computer device 1100 may also only include the components necessary to implement embodiments of the present invention, and does not necessarily include all of the devices shown in FIG.
  • the uplink wavelength of the first ONU is different from any one of the uplink wavelengths of the second ONU, so that the first ONU does not need to be cooled, which reduces the complexity and cost of the PON system.
  • the above embodiments it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof.
  • software it may be implemented in whole or in part in the form of a computer program product.
  • the computer program product includes one or more computer instructions.
  • the computer program instructions When the computer program instructions are loaded and executed on a computer, the processes or functions described in accordance with embodiments of the present invention are generated in whole or in part.
  • the computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable device.
  • the computer instructions can be stored in a computer readable storage medium or transferred from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be from a website site, computer, server or data center By wire (eg coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (eg infrared, wireless, microwave, etc.) transmission to another website site, computer, server or data center.
  • the computer readable storage medium can be any available media that can be accessed by a computer or a data storage device such as an integrated server, data center, or the like that includes one or more available media.
  • the usable medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a solid state disk (SSD)) or the like.
  • a magnetic medium eg, a floppy disk, a hard disk, a magnetic tape
  • an optical medium eg, a DVD
  • a semiconductor medium eg, a solid state disk (SSD)
  • the processor in the computer reads the computer readable program code stored in the computer readable medium such that the processor is capable of performing the various functional steps specified in each step of the flowchart, or a combination of steps; A device that functions as specified in each block, or combination of blocks.
  • the computer readable program code can execute entirely on the user's computer, partly on the user's computer, as a separate software package, partly on the user's computer and partly on the remote computer, or entirely on the remote computer or server.
  • the functions noted in the various steps in the flowcharts or in the blocks in the block diagrams may not occur in the order noted. For example, two steps, or two blocks, shown in succession may be executed substantially concurrently or the blocks may be executed in the reverse order.

Abstract

本发明实施例提供一种无源光网络PON的通信方法、装置和系统，所述PON包括光线路终端OLT和第一光网络单元ONU，该方法包括：所述OLT通过一个下行波长λdx和所述第一ONU进行通信，所述一个下行波长λdx为N个下行波长λd1～λdN中的任意一个；所述OLT通过一个上行波长λu0和所述第一ONU进行通信，所述一个上行波长λu0与M个上行波长λu1～λuM中的任意一个均不相同；其中，所述N个下行波长λd1～λdN和所述M个上行波长λu1～λuM为第二ONU配置的波长值，N、M均为大于或等于2的整数，x为1～M中的任意一个值。第一ONU的下行波长为第二ONU的下行波长中的任意一个，第一ONU的上行波长不同于第二ONU的任意一个上行波长，降低了PON系统的复杂度以及成本。

Description

一种无源光网络PON的通信方法、装置和系统 技术领域
本申请涉及接入网通信技术，尤其涉及一种无源光网络PON的通信方法、装置和系统。
背景技术
无源光网络(passive optical network，PON)是一种提供“最后一公里”网络接入的系统。PON是一种一点到多点的网络，图1是现有技术的一种PON的架构示意图。如图1所示，PON的架构包括一个位于中心局的光线路终端(optical line terminal，OLT)、一个光分配网络(optical distribution network，ODN)、以及多个位于用户驻地的光网络单元(optical network unit，ONU)。其中，ODN包括主干光纤、无源分光器(Splitter)和分支光纤。
随着无源光网络(PON)系统用户数据量的不断提升，带宽要求越来越高。通常PON系统带宽提升有两种方法，一种是提升PON系统每个波长的线路速率，另外一种方法是提升PON系统中可工作的波长数量，即在PON系统中使用更多的波长通道。例如，电气和电子工程师协会(Institute of Electrical and Electronics Engineers，IEEE)定义了三种容量的PON，分别是25Gb/s以太网无源光网络(Ethernet passive optical network，EPON),50Gb/s EPON和100Gb/s EPON。图2a为25Gb/s EPON的架构示意图，图2b为50Gb/s EPON的架构示意图，图2c为100Gb/s EPON的架构示意图。在25Gb/s EPON中，每个25G的ONU配置一对上下行波长λ1。λ1可以包括下行波长λd1和上行波长λu1。在50Gb/s EPON中，每个50G的ONU配置两对上下行波长λ1，λ2。λ1可以包括下行波长λd1和上行波长λu1，λ2可以包括下行波长λd2和上行波长λu2。在100Gb/s EPON中，每个100G的ONU配置四对上下行波长λ1，λ2，λ3，λ4。λ1可以包括下行波长λd1和上行波长λu1，λ2可以包括下行波长λd2和上行波长λu2，λ3可以包括下行波长λd3和上行波长λu3，λ4可以包括下行波长λd4和上行波长λu4。
当同一个PON系统同时具有25G的ONU和100G的ONU时，25G的ONU使用的λd1、λu1为100G的ONU中的其中一对上下行波长。25G的ONU使用的λd1、λu1的所允许的中心波长工作范围和100G的ONU使用的λd1、λu1允许中的中心波长工作范围一致，中心波长工作范围的宽度为+/-1nm。由于λu1使用+/-1nm的中心波长工作范围宽度比较窄，ONU需要制冷装置，导致PON系统的架构较复杂，成本比较高。
发明内容
本发明实施例提供了一种无源光网络PON的通信方法、装置和系统，解决PON系统的架构复杂、成本高的问题。
第一方面，本发明实施例提供一种无源光网络PON的通信方法，所述PON包括光线路终端OLT和第一光网络单元ONU，所述方法包括：所述OLT通过 一个下行波长λdx和所述第一ONU进行通信，所述一个下行波长λdx为N个下行波长λd1～λdN中的任意一个；所述OLT通过一个上行波长λu0和所述第一ONU进行通信，所述一个上行波长λu0与M个上行波长λu1～λuM中的任意一个均不相同；其中，所述N个下行波长λd1～λdN和所述M个上行波长λu1～λuM为第二ONU配置的波长值，N、M均为大于或等于2的整数，x为1～M中的任意一个值。
第一ONU和第二ONU可以部署在同一个PON系统中。第二ONU可以为除了第一ONU之外的任意一个ONU。第一ONU可以是单上行波长ONU，即具有一个上行波长的ONU。第二ONU可以是多上行波长ONU，即具有多个上行波长的ONU。第一ONU的下行波长λdx可以为第二ONU的N个下行波长的任意一个，使得第一ONU和第二ONU在OLT侧可以共用一个光发射器Tx，降低了网络部署的成本。第一ONU的上行波长λu0和第二ONU的M个上行波长均不相同，可以使第一ONU具有较宽的波长范围，从而不需要制冷，降低了ONU的制造成本，从而降低了PON系统的复杂度和成本。
一种可能的实现方式中，所述一个上行波长λu0所允许的中心波长的工作范围与M个上行波长λu1～λuM中任意一个所允许的中心波长的工作范围不同。例如，上行波长λu0所允许的中心波长工作范围为从λu0-10nm到λu0+10nm。λu1～λuM所允许的中心波长工作范围均为从λu1-1nm到λu1+1nm。
一种可能的实现方式中，上行波长λu0的波长宽度和N个上行波长λu1～λuN中任意一个波长的波长宽度可以不同。例如，上行波长λu0的波长宽度可以是20nm。N个上行波长λu1～λuN中任意一个波长的波长宽度可以比λu0窄，例如，+/-1nm，或者+/-1.5nm，甚至更窄。
一种可能的实现方式中，第一ONU可以具有一个下行波长，也可以具有多个下行波长。第一ONU有一个下行波长时，可以取第二ONU的N个下行波长的任意一个作为第一ONU的下行波长。第一ONU有多个下行波长时，第一ONU的下行波长也可以从第二ONU的N个下行波长中选取。第一ONU和第二ONU使用相同的下行波长，使得第一ONU和第二ONU在OLT侧可以共用相同的光发射器，降低了OLT的成本。
一种可能的实现方式中，第一ONU可以为对称ONU。例如，上下行均具有一个波长，且上下行速率相等的10G或25G的对称ONU。第一ONU也可为非对称ONU。例如，上下行均具有一个波长，但上行速率为10Gb/s、下行速率为25Gb/s的25G/10G的非对称ONU。或者，上行具有一个波长，下行具有多个波长，每个波长的速率为25Gb/s的100G/25G的非对称ONU。
一种可能的实现方式中，第二ONU可以为对称ONU，即M等于N。第二ONU也可以为非对称ONU，例如，M小于N。
一种可能的实现方式中，所述OLT通过所述一个下行波长λdx向所述第一ONU发送注册消息；所述OLT通过所述一个上行波长λu0接收来自所述第一ONU的注册响应消息。OLT和ONU之间的通信可以包括注册过程。在注册过程中，OLT通过上行波长λu0接收第一ONU的响应消息。在这个过程中，第一 ONU不需要制冷，节省了成本。
一种可能的实现方式中，所述OLT通过所述一个下行波长λdx向所述第一ONU发送时隙授权消息，所述时隙授权消息包括所述一个上行波长λu0的授权时隙；所述OLT通过所述一个上行波长λu0的授权时隙接收来自所述第一ONU的上行信号。OLT和ONU之间的通信可以包括数据传输过程。在数据传输过程中，OLT通过上行波长λu0接收第一ONU的上行信号。在这个过程中，第一ONU不需要制冷，节省了成本。
第二方面，本发明实施例提供一种无源光网络PON的通信方法，所述PON包括光线路终端OLT和第一光网络单元ONU，所述方法包括：所述第一ONU通过一个下行波长λdx和所述OLT进行通信，所述一个下行波长λdx为N个下行波长λd1～λdN中的任意一个；所述第一ONU通过一个上行波长λu0和所述OLT进行通信，所述一个上行波长λu0与M个上行波长λu1～λuM中的任意一个均不相同；其中，所述N个下行波长λd1～λdN和所述M个上行波长λu1～λuM为第二ONU配置的波长值，N、M均为大于或等于2的整数，x为1～M中的任意一个值。
第一ONU和第二ONU可以部署在同一个PON系统中。第二ONU可以为除了第一ONU之外的任意一个ONU。第一ONU可以是单上行波长ONU，即具有一个上行波长的ONU。第二ONU可以是多上行波长ONU，即具有多个上行波长的ONU。第一ONU的下行波长λdx可以为第二ONU的N个下行波长的任意一个，使得第一ONU和第二ONU在OLT侧可以共用一个光发射器Tx，降低了网络部署的成本。第一ONU的上行波长λu0和第二ONU的M个上行波长均不相同，可以使第一ONU具有较宽的波长范围，从而不需要制冷，降低了ONU的制造成本，从而降低了PON系统的复杂度和成本。
一种可能的实现方式中，所述一个上行波长λu0所允许的中心波长的工作范围与M个上行波长λu1～λuM中任意一个所允许的中心波长的工作范围不同。例如，上行波长λu0所允许的中心波长工作范围为从λu0-10nm到λu0+10nm。λu1～λuM所允许的中心波长工作范围均为从λu1-1nm到λu1+1nm。
一种可能的实现方式中，上行波长λu0的波长宽度和N个上行波长λu1～λuN中任意一个波长的波长宽度可以不同。例如，上行波长λu0的波长宽度可以是20nm。N个上行波长λu1～λuN中任意一个波长的波长宽度可以比λu0窄，例如，+/-1nm，或者+/-1.5nm，甚至更窄。
一种可能的实现方式中，第一ONU可以具有一个下行波长，也可以具有多个下行波长。第一ONU有一个下行波长时，可以取第二ONU的N个下行波长的任意一个作为第一ONU的下行波长。第一ONU有多个下行波长时，第一ONU的下行波长也可以从第二ONU的N个下行波长中选取。第一ONU和第二ONU使用相同的下行波长，使得第一ONU和第二ONU在OLT侧可以共用相同的光发射器，降低了OLT的成本。
一种可能的实现方式中，第一ONU可以为对称ONU。例如，上下行均具有一个波长，且上下行速率相等的10G或25G的对称ONU。第一ONU也可为非对称 ONU。例如，上下行均具有一个波长，但上行速率为10Gb/s、下行速率为25Gb/s的25G/10G的非对称ONU。或者，上行具有一个波长，下行具有多个波长，每个波长的速率为25Gb/s的100G/25G的非对称ONU。
一种可能的实现方式中，第二ONU可以为对称ONU，即M等于N。第二ONU也可以为非对称ONU，例如，M小于N。
一种可能的实现方式中，所述方法包括：所述第一ONU通过所述一个下行波长λdx接收来自所述OLT的注册消息；所述第一ONU通过所述一个上行波长λu0向所述OLT发送注册响应消息。OLT和ONU之间的通信可以包括注册过程。在注册过程中，第一ONU通过上行波长λu0向OLT发送注册响应消息。在这个过程中，第一ONU不需要制冷，节省了成本。
一种可能的实现方式中，所述方法包括：所述第一ONU通过所述一个下行波长λdx接收来自所述OLT的时隙授权消息，所述时隙授权消息包括所述一个上行波长λu0的授权时隙；所述第一ONU通过所述一个上行波长λu0的授权时隙向所述OLT发送上行信号。OLT和ONU之间的通信可以包括数据传输过程。在数据传输过程中，第一ONU通过上行波长λu0向所述OLT发送上行信号。在这个过程中，第一ONU不需要制冷，节省了成本。
第三方面，本发明实施例提供一种OLT，该OLT能够执行第一方面及第一方面任意一种可能的实现方式中的方法步骤的功能。所述功能可以通过硬件实现，也可以通过硬件执行相应的软件实现。所述硬件或软件包括一个或多个与上述功能相对应的模块。所述模块可以是软件和/或硬件。
在一个可能的实现方式中，OLT的结构中包括光发射器和光接收器。所述发射器器和光接收器用于支持OLT与ONU之间的通信，光发射器用于向ONU发送上述方法中所涉及的信息或者指令，光接收器用于接收ONU所发送的信息或指令。所述OLT还可以包括存储器，所述存储器用于与处理器耦合，其保存OLT必要的程序指令和数据。
第四方面，本发明实施例提供一种ONU，该ONU能够执行第二方面及第二方面任意一种可能的实现方式中的方法步骤的功能。所述功能可以通过硬件实现，也可以通过硬件执行相应的软件实现。所述硬件或软件包括一个或多个与上述功能相对应的模块。所述模块可以是软件和/或硬件。
在一种可能的实现方式中，ONU的结构中包括光发射器和光接收器。所述发射器器和光接收器用于支持OLT与ONU之间的通信，光发射器用于向OLT发送上述方法中所涉及的信息或者指令，光接收器用于接收OLT所发送的信息或指令。所述ONU还可以包括存储器，所述存储器用于与处理器耦合，其保存ONU必要的程序指令和数据。
又一方面，本发明实施例提供了一种PON系统，该PON系统包括上述方面所述的OLT和ONU。
本申请的又一方面提供了一种计算机可读存储介质，所述计算机可读存储介质中存储有指令，当其在计算机上运行时，使得计算机执行上述各方面所述的方法。
本申请的又一方面提供了一种包含指令的计算机程序产品，当其在计算机上运行时，使得计算机执行上述各方面所述的方法。
附图说明
为了更清楚地说明本发明实施例，下面将对实施例描述中所需要使用的附图作简单地介绍。
图1是现有技术的一种PON的架构示意图；
图2a为25Gb/s EPON的架构示意图；
图2b为50Gb/s EPON的架构示意图；
图2c为100Gb/s EPON的架构示意图；
图3a是本发明实施例提供的一种PON系统300a的架构示意图；
图3b是本发明实施例提供的另一种PON系统300b的架构示意图；
图4a是本发明实施例提供的一种OLT 400a的结构示意图；
图4b是本发明实施例提供的一种OLT 400b的结构示意图；
图5是本发明实施例提供的一种波长分布的示意图；
图6a是本发明实施例提供的一种ONU 600a的结构示意图；
图6b是本发明实施例提供的一种ONU 600b的结构示意图；
图6c是本发明实施例提供的一种ONU 600c的结构示意图；
图7是本发明实施例提供的一种ONU注册的信令交互示意图；
图8是本发明实施例提供的一种ONU数据传输的交互示意图；
图9是本发明实施例提供的一种无源光网络PON的通信方法的示范性流程图；
图10是本发明实施例提供的一种无源光网络PON的通信方法的示范性流程图；
图11为本发明实施例提供的一种网络设备1100的结构示意图。
具体实施方式
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描述。
为了提升无源光网络PON系统的带宽，支持多个波长(或波长通道/波长信道)的PON系统已经被提出，例如，背景技术中提到的50G EPON和100G EPON等。在PON系统中，ONU可以被配置多对上下行波长(两对及以上)。也可以被配置一对上下行波长。波长的数目不同，ONU的速率可以不同。例如，具有一对上下行波长的ONU可以包括上下行速率均为10G或25G的ONU，具有多对上下行波长的ONU可以包括上下行速率均为100G或50G的ONU等。以上所述的几种ONU，上下行的速率可以是相同的，上下行的波长数目也可以是相同的，称为对称ONU。
实际网络中，上下行业务的流量可以不相同，例如，对于住宅用户，通常其下行业务流量远远大于上行的业务流量，因此同一个ONU的上下行的速率可以 不一样，例如λd1上的下行速率可以是25Gb/s，而对应的上行速率可以为10Gb/s，而这样的ONU则构成一个25G/10G的非对称ONU。另一个例子中，ONU的下行波长数目和上行波长数目可以不相同，例如一个ONU可以有4个下行波长λd1、λd2、λd3、λd4，而只有一个上行波长λu1，每个波长速率25Gb/s，构成100G/25G的非对称ONU；或者上行有两个上行波长λu1和λu2，构成一个100G/50G的非对称ONU。
本发明实施例所说的单上行波长ONU，可以包括上下行波长均只有一个波长的ONU；也可以包括有一个上行波长、多个下行波长的ONU。多上行波长ONU，可以包括上下行波长均有多个波长的ONU；或者有多上行波长、一个下行波长的ONU。总的来说，上行波长只有一个波长的ONU，不管是对称ONU，还是非对称ONU，都可以是本发明实施例所说的单上行波长ONU。
在网络部署的过程中，多上行波长ONU和单上行波长ONU可以部署在同一个PON系统中，共用ODN等网络设备，以节省网络升级的成本。本发明实施例可以应用于多上行波长ONU和单上行波长ONU并存的PON系统中，并且可以节省单上行波长ONU的制造成本。本发明实施例可以应用于多种PON系统，例如，异步传输模式PON(asynchronous transfer mode PON，APON)、宽带PON(broadband PON，BPON)、以太网PON(Ethernet PON，EPON)、10千兆比特EPON(10gigabite-EPON，10G-EPON)、千兆比特PON(gigabit-capable PON，GPON)、XGPON、波分复用PON(wavelength division multiplexing-PON，WDM-PON、时分波分复用PON(time wavelength division multiplexing-PON，TWDM-PON)，还可以应用于下一代PON(next generation PON，NGPON)系统、NG-PON2等。
图3a是本发明实施例提供的一种PON系统300a的架构示意图。如图3a所示，PON系统300a包括至少一个OLT 301、多个ONU 303和ODN 305。OLT 301通过ODN 305以点到多点的形式连接到多个ONU 303。其中，从OLT 301到ONU 303的方向可以为下行方向，从ONU 303到OLT 301的方向可以为上行方向。在下行方向上，OLT 301可以向ONU 303发送下行波长信号；在上行方向上，ONU 303可以向OLT 301发送上行波长信号。波长信号可以是具有某种波长的光信号载体，用来承载数据、信息或消息等。多个ONU 303中可以包括至少一个单上行波长ONU，例如25G的ONU，还可以包括至少一个多上行波长ONU，例如100G的ONU。可选的，多个ONU 303中还可以包括至少一个其他速率的ONU，例如50G的ONU。单上行波长ONU使用一对上下行波长。例如，25G的ONU使用下行波长λd1、上行波长λu0。多上行波长ONU使用两对或以上的上下行波长。例如，50G的ONU使用下行波长λd1、λd2，上行波长λu1、λu2。100G的ONU使用下行波长λd1、λd2、λd3、λd4，上行波长λu1、λu2、λu3、λu4。
图3b是本发明实施例提供的另一种PON系统300b的架构示意图。图3b和图3a的区别在于，图3b中，PON系统300b还可以包括其他速率的单上行波长ONU，例如10G的ONU。可选的，PON系统300b还可以包括非对称的单上行波长ONU，例如25G/10G的非对称ONU、或者100G/25G的非对称ONU， 图中未示出。在PON系统300b中，25G的ONU和10G的ONU可以使用相同的上行波长λu0。25G的ONU和10G的ONU可以是使用不同的下行波长。比如，10G的ONU使用下行波长λd0，25G的ONU使用下行波长λd1。可选的，25G的ONU和10G的ONU也可以使用相同的下行波长。
下面分别介绍PON系统300a、300b中各个网络设备的结构以及工作原理。
OLT
OLT 301通常位于中心位置，例如，中心局(central office，CO)。OLT 301可以充当ONU 303和上层网络(图中未示出)之间的传输媒介，将从上层网络接收到的信号作为下行信号转发到ONU 303，或者将从ONU 303接收到的上行信号转发到上层网络。
图4a是本发明实施例提供的一种OLT 400a的结构示意图。图3a中的OLT301可以参考OLT 400a的结构。如图4a所示，OLT 400a可以包括光发射器Tx1～Tx4 401、光接收器Rx0～Rx4 403、复用器405、光耦合器407和解复用器409。光发射器Tx1～Tx4 401用于产生下行波长信号，例如，图中示出了四个下行波长信号λd1、λd2、λd3、λd4。四个下行波长信号经过复用器405之后合并为一路光信号，经过光耦合器407后发送到ODN 305。光接收器Rx0～Rx4 403用于接收上行波长信号，例如，图中示出了五个上行波长信号λu0、λu1、λu2、λu3、λu4。上行波长信号λu0、λu1、λu2、λu3、λu4经过光耦合器407后分为两路，一路包括λu0，被Rx0接收，另一路包括λu1、λu2、λu3、λu4，分别被Rx1～Rx4接收。可选的，可以在光接收器Rx1～Rx4前增加前置放大器，例如半导体光放大器(semiconductor optical amplifier，SOA)411。上行的波长信号λu1、λu2、λu3、λu4经过光解复用器409进行分光；然后进入SOA 411进行光功率放大；然后经过窄带滤波器413，滤除有效光信号以外的自发辐射光信号；然后进入光接收器Rx，例如雪崩二极管(avalanche photodiode，APD)。前置放大器提供的灵敏度增益，通常取决于其增益噪声指数。而窄带滤波器可以很好地滤除信号带外的噪声，可以有效地提高放大器所带来的增益。例如，当没有窄带滤波器时，放大器仅能提供1.3dB的增益，而增加一个窄带滤波器以后，放大器可以提供4.3dB的增益，灵敏度可以得到明显的提升。
图4b是本发明实施例提供的一种OLT 400b的结构示意图。图3b中的OLT301可以参考OLT 400b的结构。图4b的OLT 400b和图4a的OLT 400a的区别在于，图4b的OLT 400b多了一个10G的光发射器Tx0，用于产生发送给10G的ONU的下行波长信号λd0。OLT 400b可以通过同一个光接收器10G/25G Dual Rx0接收来自25G的ONU和10G的ONU的上行波长信号λu0。在10G的ONU和25G的ONU共存的PON系统中，25G的ONU可以和10G的ONU共用一个上行波长λu0，以及OLT可以使用同一个光接收器Rx0来接收10G的ONU和25G的ONU的上行波长信号λu0，节省了网络升级的成本。
对于采用前置放大器的OLT，波长信号需要分布在一个比较窄的范围，这样可以便于前置放大器后的窄带滤波器进行滤波。OLT接收来自ONU的上行波长信号，为了使OLT侧的前置放大器提供足够大的增益，以满足功率要求，ONU 上行波长允许的中心波长工作范围的宽度(可以简称“波长宽度”)通常可以为+/-1nm或+/-1.5nm，甚至更窄的宽度。图5是本发明实施例提供的一种波长分布的示意图。如图5所示，针对100G的ONU，可以配置四个相同波长宽度的下行波长λd1、λd2、λd2、λd4和四个相同波长宽度的上行波长λu1、λu2、λu3、λu4。针对25G的ONU，可以配置100G的ONU四个下行波长λd1～λd4中的λd1作为下行波长，配置一个较宽波长宽度的上行波长λu0。例如，λu1～λu4的波长宽度可以为+/-1nm或+/-1.5nm，或者在+/-1nm～+/-1.5nm之间，或者小于+/-1nm。λu0的波长宽度大于λu1～λu4中任意一个的波长宽度，如+/-10nm。
表1为下行波长λd1～λd4以及上行波长λu0～λu4所允许的中心波长工作范围的例子。λu0所允许的中心波长的工作范围可以和100G的ONU中四个上行波长λu1～λu4中任意一个所允许的中心波长的工作范围均不相同。λu0的波长宽度可以与λu1～λu4中任意一个的波长宽度不同。例如，λu1的中心波长是1289.71nm，λu1所允许的中心波长工作范围为1288.71nm～1290.71nm，波长宽度为2nm。λu2的中心波长是1294.16nm，λu2所允许的中心波长工作范围为1293.16nm～1295.16nm，波长宽度为2nm。λu3的中心波长是1298.65nm，λu3所允许的中心波长工作范围为1297.65nm～1299.65nm，波长宽度为2nm。λu4的中心波长是1303.16nm，λu4所允许的中心波长工作范围为1302.16nm～1304.16nm，波长宽度为2nm。λu0的中心波长是1270nm，λu0所允许的中心波长工作范围为1260nm～1280nm，波长宽度为20nm。
表1
波长值(wavelength) 波长工作范围(range/band)
λd1 1334.78±1nm
λd2 1349.20±1nm
λd3 1354.08±1nm
λd4 1358.99±1nm
λu1 1289.71±1nm
λu2 1294.16±1nm
λu3 1298.65±1nm
λu4 1303.16±1nm
λu0 1270±10nm
ONU
ONU 303可以分布式地设置在用户侧位置，例如用户驻地。ONU 303可以充当OLT 301和用户设备之间的媒介，例如，ONU 303可以将从OLT 301接收到的下行信号转发给用户设备，或者将从用户设备接收到的信号作为上行信号转发到OLT 301。用户设备可以包括个人电脑(personal computer，PC)、便携电子设备等终端设备。应当理解，ONU 303的结构与光网络终端(optical network terminal，ONT)相近，因此，本发明实施例中，ONU和ONT可以互换。
图6a是本发明实施例提供的一种ONU 600a的结构示意图。ONU 600a可以 为25G的ONU。如图6a所示，ONU 600a可以包括光接收器Rx1 601、光发射器Tx0 603和WDM 605。光发射器Rx1 601用于接收来自OLT的下行波长信号λd1，光发射器Tx0 603用于向OLT发送上行波长信号λu0。WDM 605用于对上行波长信号和上行波长信号进行波分复用。
图6b是本发明实施例提供的一种ONU 600b的结构示意图。ONU 600b可以为100G的ONU。如图6b所示，ONU 600b可以包括光接收器Rx1～Rx4 601、光发射器Tx1～Tx4 603、WDM 605和光复用器607。光发射器Rx1～Rx4 601用于分别接收来自OLT的下行波长信号λd1～λd4，光发射器Tx1～Tx4 603用于向OLT发送上行波长信号λu1～λu4。WDM 605用于对每一对上行波长信号和上行波长信号进行波分复用。光复用器607用于将下行波长信号λd1～λd4进行分波，对上行波长信号λu1～λu4进行合波。
图6c是本发明实施例提供的一种ONU 600c的结构示意图。ONU 600c也可以为100G的ONU。图6c和图6b的差别在于，WDM 605和光复用器607设置的位置不同。
10G的ONU和25G的ONU结构类似，区别在于10G的ONU使用的下行波长可以和25G的ONU使用的下行波长λd1不同，以及波长的线路速率不同。50G的ONU和100G的ONU结构类似，区别在于光接收器包括Rx1、Rx2，光发射器包括Tx1、Tx2，此处不再赘述。
不同的ONU可以配置相同的波长。例如，25G的ONU的下行波长λd1可以是50G的ONU或100G的ONU中的其中一个下行波长。当不同的ONU使用相同的波长时，不同的ONU可以通过时分复用的方式使用该波长上的不同时隙。例如，25G的ONU和100G的ONU通过时分复用的方式使用下行波长λd1上的不同时隙。同一个ONU也可以配置多个不同的波长，或者不同的ONU配置不同的波长。同一个ONU或不同的ONU可以通过波分复用的方式使用不同的波长。例如，100G的ONU可以通过波分复用的方式使用四个不同的下行波长λd1～λd4或四个不同的上行波长λu1～λu4。25G的ONU和100G的ONU可以通过波分复用的方式使用五个不同的上行波长λu0～λu4。
ODN
PON系统300可以不需要任何有源器件来实现OLT 301和ONU 303之间的ODN 305。例如，ODN 305可以包括无源分光器(Splitter)或复用器、光纤等无源光器件。ODN 305可以采用分光比为1:4、1:8、1:6、1:32或者1:64的分光器。例如，图中示出了1:4的Splitter，包括一个公共端口和四个分支端口。Splitter通过公共端口和主干光纤、OLT 301相连，Splitter通过四个分支端口和分支光纤分别、四个ONU 303相连。可选的，ODN 305可以通过两级或以上的分光器进一步提高分光比。
本发明实施例中，在单上行波长ONU和多上行波长ONU共存的PON系统中，将与多上行波长ONU多个上行波长中任意一个均不相同的一个波长配置为单上行波长ONU的上行波长。使得单上行波长ONU的上行波长具有较宽的中心波长工作范围而不需要制冷，降低了PON系统的复杂度以及成本。
下面介绍OLT和ONU之间的通信过程及原理。OLT和ONU之间的通信可以包括ONU上线注册和ONU数据传输。在OLT和ONU通信的过程中，OLT向ONU发送下行波长信号，ONU向OLT发送上行波长信号。因此，需要在OLT和ONU上分别配置上行波长和下行波长。波长配置的方式可以直接在OLT和ONU的光发射器和光接收器上进行配置。例如，在OLT或ONU中调整激光器的发射波长或APD的接收波长至某个波长值。波长配置的方式还可以通过网管或OLT进行动态配置。例如，OLT将某个波长值动态配置为ONU激光器的发射波长或APD的接收波长。
图7是本发明实施例提供的一种ONU注册的信令交互示意图。对于单上行波长ONU的注册过程，以25G的ONU为例进行说明，参见图7。
701、OLT在下行波长λd1的广播信道上周期性地产生合法的发现时间窗口，例如，通过Gate消息产生发现时间窗口。Gate消息中可以包括发现窗口的时间和长度。
702、25G的ONU(以下步骤703-705简称ONU)通过光接收器接收到Gate消息后，当Gate消息中的发现时间窗口的周期开始时，在上行波长λu0上发送注册请求消息。例如，该注册请求消息可以为Register_REQ消息。
703、OLT在接收到ONU的注册请求消息后，为该ONU分配ONU的逻辑链路ID(Logical Link Identifier，LLID)，并在下行波长λd1向ONU发送Register消息，用于完成测距。Register消息中可以包括ONU的LLID、OLT要求的同步时间等信息。
704、OLT在下行波长λd1向ONU发送时隙授权消息，例如Gate消息。时隙授权消息中包括上行波长λu0的授权时隙，即允许ONU在上行波长λu0发送注册响应消息的授权时隙。可选的，时隙授权消息也可以携带在OLT发给ONU的Register消息中。
705、ONU收到Register消息后，在时隙授权消息中上行波长λu0的授权时隙返回注册响应消息。例如，注册响应消息可以为Register_ACK消息。
OLT收到注册响应消息后可以完成测距，计算ONU到OLT的距离或者ONU和OLT之间传输信息所需要的时间。
可选的，在步骤703中，测距也可以通过701的Gate消息和702的Register_REQ消息来实现。即，测距可以在702之后完成，也可以在705之后完成。
对于多上行波长ONU的注册过程，以100G的ONU为例进行说明。100G的ONU注册的信令交互过程和25G的ONU类似，也可以参见图7。
701、OLT在一个或多个下行波长(例如，下行波长λd1～λd4中的其中一个或多个)的广播信道上周期性地产生合法的发现时间窗口，例如，通过Gate消息产生发现时间窗口。Gate消息中可以包括发现窗口的时间和长度。
702、100G的ONU(以下步骤703-705简称ONU)通过光接收器接收到Gate消息后，当Gate消息中的发现时间窗口的周期开始时，在其中一个或多个上行波长(例如，上行波长λu1～λu4中的其中一个或多个)向OLT发送注册请 求消息。例如，该注册请求消息可以为Register_REQ消息。注册请求消息中可以包括ONU的波长信息，例如上下行的波长通道数、波长通道等。上行波长通道可以包括四个上行波长λu1～λu4，下行波长通道可以包括四个下行波长λd1～λd4。
703、OLT收到ONU的注册请求消息后，为该ONU分配ONU的LLID，以及每个波长通道的通道标识。OLT在每个下行波长通道(例如，下行波长λd1～λd4)发送Register消息，用于完成每个波长通道的测距。Register消息中可以包括ONU的LLID、OLT要求的同步时间等信息。
704、OLT在每个下行波长通道上(例如，下行波长λd1～λd4)发送时隙授权消息。时隙授权消息中包括各个上行波长(例如，下行波长λu1～λu4)的授权时隙，即允许ONU在上行波长λu1～λu4发送注册响应消息的授权时隙。例如，OLT在下行波长λd1上发送包含上行波长λu1的授权时隙的时隙授权消息，在下行波长λd2上发送包含上行波长λu2的授权时隙的时隙授权消息……以此类推。可选的，时隙授权消息也可以携带在OLT发给ONU的Register消息中。
705、ONU收到Register消息后，在时隙授权消息中上行波长λu1～λu4的授权时隙返回注册响应消息。例如，注册响应消息可以为Register_ACK消息。
OLT收到注册响应消息后可以完成测距，计算ONU到OLT的距离或者ONU和OLT之间传输信息所需要的时间。
可选的，在步骤703中，测距也可以通过701的Gate消息和702的Register_REQ消息来实现。即，测距可以在702之后完成，也可以在705之后完成。
图8是本发明实施例提供的一种ONU数据传输的交互示意图。在完成注册之后，ONU和OLT之间可以进行数据传输。对于单上行波长ONU的数据传输过程，以25G的ONU为例进行说明，参见图8。
801、OLT在下行波长λd1上向25G的ONU发送时隙授权消息，其中，时隙授权消息中可以包含25G的ONU在上行波长λu0的授权时隙。上行波长λu0的授权时隙，即允许25G的ONU发送上行信号的时隙。
802、25G的ONU在时隙授权消息包含的上行波长λu0的授权时隙，通过上行波长λu0向OLT发送上行信号。
对于多上行波长ONU的数据传输过程，以100G的ONU为例进行说明。100G的ONU数据传输交互过程和25G的ONU类似，也可以参见图8。
801、OLT在下行波长λd1上向100G的ONU发送第一时隙授权消息，其中，第一时隙授权消息中可以包含100G的ONU在上行波长λu1的授权时隙。OLT在下行波长λd2上向100G的ONU发送第二时隙授权消息，其中，第二时隙授权消息中可以包含100G的ONU在上行波长λu2的授权时隙。OLT在下行波长λd3上向100G的ONU发送第三时隙授权消息，其中，第三时隙授权消息中可以包含100G的ONU在上行波长λu3的授权时隙。OLT在下行波长λd4上向100G的ONU发送时隙授权消息，其中，时隙授权消息中可以包含100G的ONU在上行波长λu4的授权时隙。
OLT进行上行时隙授权时，需要在多个波长通道上统一调度计算，对使用同一波长的ONU分配不同的时隙。对于每个上行波长，不同的ONU在同一波长上发送的上行信号到达OLT光接收器的时间不能相互重叠，避免发生冲突。例如，100G的ONU和50G的ONU具有相同的上行波长λu1、λu2，100G的ONU和50G的ONU在上行波长λu1或λu2上通过时分复用的方式使用不同时隙。
802、100G的ONU在时隙授权消息包含的上行波长λu1的授权时隙，通过上行波长λu1向OLT发送上行信号。100G的ONU在时隙授权消息包含的上行波长λu2的授权时隙，通过上行波长λu2向OLT发送上行信号。100G的ONU在时隙授权消息包含的上行波长λu3的授权时隙，通过上行波长λu3向OLT发送上行信号。100G的ONU在时隙授权消息包含的上行波长λu4的授权时隙，通过上行波长λu4向OLT发送上行信号。
图9是本发明实施例提供的一种无源光网络PON的通信方法的示范性流程图。所述PON包括光线路终端OLT和第一光网络单元ONU，包括如下步骤：
901：所述OLT通过一个下行波长λdx和所述第一ONU进行通信，所述一个下行波长λdx为N个下行波长λd1～λdN中的任意一个；
902：所述OLT通过一个上行波长λu0和所述第一ONU进行通信，所述一个上行波长λu0与M个上行波长λu1～λuM中的任意一个均不相同；
其中，所述N个下行波长λd1～λdN和所述M个上行波长λu1～λuM为第二ONU配置的波长值，N、M均为大于或等于2的整数，x为1～M中的任意一个值。
可选的，所述一个上行波长λu0所允许的中心波长的工作范围与M个上行波长λu1～λuM中任意一个所允许的中心波长的工作范围不同。可选的，上行波长λu0的波长宽度和N个上行波长λu1～λuN中任意一个波长的波长宽度可以不同。
OLT和ONU的通信过程可以包括注册过程和数据传输过程。
可选的，OLT通过所述一个下行波长λdx向所述第一ONU发送注册消息；所述OLT通过所述一个上行波长λu0接收来自所述第一ONU的注册响应消息。
可选的，所述OLT通过所述一个下行波长λdx向所述第一ONU发送时隙授权消息，所述时隙授权消息包括所述一个上行波长λu0的授权时隙；所述OLT通过所述一个上行波长λu0的授权时隙接收来自所述第一ONU的上行信号。
图9所示的方法步骤可以通过图4a或图4b所示的OLT执行。例如，光发射器Tx1～Tx4中任意一个，用于通过一个下行波长λdx和所述第一ONU进行通信，所述一个下行波长λdx为N个下行波长λd1～λdN中的任意一个；光接收器Rx0，用于通过一个上行波长λu0和所述第一ONU进行通信，所述一个上行波长λu0与M个上行波长λu1～λuM中的任意一个均不相同；其中，所述N个下行波长λd1～λdN和所述M个上行波长λu1～λuM为第二ONU配置的波长值，N、M均为大于或等于2的整数，x为1～M中的任意一个值。
可选的，所述一个上行波长λu0所允许的中心波长的工作范围与M个上行波长λu1～λuM中任意一个所允许的中心波长的工作范围不同。可选的，上行 波长λu0的波长宽度和N个上行波长λu1～λuN中任意一个波长的波长宽度可以不同。
OLT和ONU的通信过程可以包括注册过程和数据传输过程。
可选的，光发射器Tx1～Tx4中任意一个，通过所述一个下行波长λdx向所述第一ONU发送注册消息；光接收器Rx0，通过所述一个上行波长λu0接收来自所述第一ONU的注册响应消息。
可选的，光发射器Tx1～Tx4中任意一个，通过所述一个下行波长λdx向所述第一ONU发送时隙授权消息，所述时隙授权消息包括所述一个上行波长λu0的授权时隙；光接收器Rx0，通过所述一个上行波长λu0的授权时隙接收来自所述第一ONU的上行信号。
根据本发明实施例提供的技术方案，第一ONU的下行波长为第二ONU的下行波长中的任意一个，第一ONU和第二ONU可以在OLT侧共用一个光发射器。第一ONU的上行波长不同于第二ONU的任意一个上行波长，使得第一ONU不需要制冷，降低了PON系统的复杂度以及成本。
图10是本发明实施例提供的一种无源光网络PON的通信方法的示范性流程图。所述PON包括光线路终端OLT和第一光网络单元ONU，包括如下步骤：
1001：所述第一ONU通过一个下行波长λdx和所述OLT进行通信，所述一个下行波长λdx为N个下行波长λd1～λdN中的任意一个；
1002：所述第一ONU通过一个上行波长λu0和所述OLT进行通信，所述一个上行波长λu0与M个上行波长λu1～λuM中的任意一个均不相同；
其中，所述N个下行波长λd1～λdN和所述M个上行波长λu1～λuM为第二ONU配置的波长值，N、M均为大于或等于2的整数，x为1～M中的任意一个值。
可选的，所述一个上行波长λu0所允许的中心波长的工作范围与M个上行波长λu1～λuM中任意一个所允许的中心波长的工作范围不同。可选的，上行波长λu0的波长宽度和N个上行波长λu1～λuN中任意一个波长的波长宽度可以不同。
可选的，所述第一ONU通过所述一个下行波长λdx接收来自所述OLT的注册消息；所述第一ONU通过所述一个上行波长λu0向所述OLT发送注册响应消息。
可选的，所述第一ONU通过所述一个下行波长λdx接收来自所述OLT的时隙授权消息，所述时隙授权消息包括所述一个上行波长λu0的授权时隙；所述第一ONU通过所述一个上行波长λu0的授权时隙向所述OLT发送上行信号。
图10所示的方法步骤可以通过图6a所示的ONU执行。例如，光接收器Rx1，用于通过一个下行波长λdx和所述OLT进行通信，所述一个下行波长λdx为N个下行波长λd1～λdN中的任意一个；光发射器Tx0，用于通过一个上行波长λu0和所述OLT进行通信，所述一个上行波长λu0与M个上行波长λu1～λuM中的任意一个均不相同。其中，所述N个下行波长λd1～λdN和所述M个上行波长λu1～λuM为第二ONU配置的波长值，N、M均为大于或等于2的整数， x为1～M中的任意一个值。
可选的，所述一个上行波长λu0所允许的中心波长的工作范围与M个上行波长λu1～λuM中任意一个所允许的中心波长的工作范围不同。可选的，上行波长λu0的波长宽度和N个上行波长λu1～λuN中任意一个波长的波长宽度可以不同。
可选的，光接收器Rx1，用于通过所述一个下行波长λdx接收来自所述OLT的注册消息；光发射器Tx0，用于通过所述一个上行波长λu0向所述OLT发送注册响应消息。
可选的，光接收器Rx1，用于通过所述一个下行波长λdx接收来自所述OLT的时隙授权消息，所述时隙授权消息包括所述一个上行波长λu0的授权时隙；光发射器Tx0，用于通过所述一个上行波长λu0的授权时隙向所述OLT发送上行信号。
根据本发明实施例提供的技术方案，第一ONU的下行波长为第二ONU的下行波长中的任意一个，第一ONU和第二ONU可以在OLT侧共用一个光发射器。第一ONU的上行波长不同于第二ONU的任意一个上行波长，使得第一ONU不需要制冷，降低了PON系统的复杂度以及成本。
本发明实施例提供一种PON系统，包括OLT、第一ONU和第二ONU，所述第一ONU被配置一个下行波长λdx和一个上行波长λu0，所述第二ONU被配置N个下行波长λd1～λdN和M个上行波长λu1～λuM。OLT具有图4a或图4b所示的结构，执行如图9所示的方法步骤。第一ONU可以具有图6a所示的结构，执行如图10所示的方法步骤。第二ONU可以具有如图6b或图6c所示的结构。
图11为本发明实施例提供的一种网络设备1100的结构示意图。如图11所示，网络设备1100包括：包括处理器1101、存储器1102和收发器1003。可选的，收发器1103中还可以包括媒体访问控制(medium access control，MAC)1104。网络设备1100还可以包括WDM 1105和通信接口1106。上述实施例中的任意一个OLT或ONU都可以具有类似网络设备1100的结构。
处理器1101可以采用通用的中央处理器(Central Processing Unit，CPU)，微处理器，应用专用集成电路(Application Specific Integrated Circuit，ASIC)，或者至少一个集成电路，用于执行相关程序，以实现本发明实施例所提供的技术方案。
存储器1102可以是只读存储器(Read Only Memory，ROM)，静态存储设备，动态存储设备或者随机存取存储器(Random Access Memory，RAM)。存储器1102可以存储操作系统和其他应用程序。在通过软件或者固件来实现本发明实施例提供的技术方案时，用于实现本发明实施例提供的技术方案的程序代码保存在存储器1102中，并由处理器1101来执行。
收发器1103可以包括光发射器和/或光接收器。光发射器可以用于发送信号，光接收器可以用于接收信号。光发射器可以通过发光器件，例如气体激光器、固体激光器、液体激光器、半导体激光器等实现。光接收器可以通过光检测器，例 如光电检波器或者光电二极管等实现。
收发器1103可以耦合到WDM 1105，当向通信接口1106发送信号时，WDM1105充当复用器，当从通信接口1106接收信号时，WDM 1105充当解复用器。WDM 1105也可以称为光耦合器。通信接口1106可以耦合到ODN。
当网络设备1100为OLT时，网络设备1100的收发器1103，通过一个下行波长λdx和所述第一ONU进行通信，所述一个下行波长λdx为N个下行波长λd1～λdN中的任意一个；通过一个上行波长λu0和所述第一ONU进行通信，所述一个上行波长λu0与M个上行波长λu1～λuM中的任意一个均不相同；其中，所述N个下行波长λd1～λdN和所述M个上行波长λu1～λuM为第二ONU配置的波长值，N、M均为大于或等于2的整数，x为1～M中的任意一个值。
可选的，上述功能可以在处理器1101的控制下执行，例如，处理器1101执行保存于存储器1102的代码，实现上述的功能。
当网络设备1100为ONU时，网络设备1100的收发器1103，通过一个下行波长λdx和所述OLT进行通信，所述一个下行波长λdx为N个下行波长λd1～λdN中的任意一个；通过一个上行波长λu0和所述OLT进行通信，所述一个上行波长λu0与M个上行波长λu1～λuM中的任意一个均不相同；其中，所述N个下行波长λd1～λdN和所述M个上行波长λu1～λuM为第二ONU配置的波长值，N、M均为大于或等于2的整数，x为1～M中的任意一个值。
可选的，上述功能可以在处理器1101的控制下执行，例如，处理器1101执行保存于存储器1102的代码，实现上述的功能。
具体地，通过图11所示的网络设备1100可以实现图9或图10所示的方法步骤。应注意，尽管图11所示的网络设备1100仅仅示出了处理器1101、存储器1102、收发器1103、MAC 1104、WDM 1105以及通信接口1106，但是在具体实现过程中，本领域的技术人员应当明白，网络设备1100还包含实现正常运行所必须的其他器件。同时，根据具体需要，本领域的技术人员应当明白，网络设备1100还可包含实现其他附加功能的硬件器件。此外，本领域的技术人员应当明白，计算机设备1100也可仅仅包含实现本发明实施例所必须的器件，而不必包含图11中所示的全部器件。
根据本发明实施例提供的技术方案，第一ONU的上行波长不同于第二ONU的任意一个上行波长，使得第一ONU不需要制冷，降低了PON系统的复杂度以及成本。
在上述实施例中，可以全部或部分地通过软件、硬件、固件或者其任意组合来实现。当使用软件实现时，可以全部或部分地以计算机程序产品的形式实现。所述计算机程序产品包括一个或多个计算机指令。在计算机上加载和执行所述计算机程序指令时，全部或部分地产生按照本发明实施例所述的流程或功能。所述计算机可以是通用计算机、专用计算机、计算机网络、或者其他可编程装置。所述计算机指令可以存储在计算机可读存储介质中，或者从一个计算机可读存储介质向另一个计算机可读存储介质传输，例如，所述计算机指令可以从一个网站站点、计算机、服务器或数据中心通过有线(例如同轴电缆、光纤、数字用户线 (DSL))或无线(例如红外、无线、微波等)方式向另一个网站站点、计算机、服务器或数据中心进行传输。所述计算机可读存储介质可以是计算机能够存取的任何可用介质或者是包含一个或多个可用介质的集成服务器、数据中心等数据存储设备。所述可用介质可以是磁性介质，(例如，软盘、硬盘、磁带)、光介质(例如，DVD)、或者半导体介质(例如，固态硬盘Solid State Disk(SSD))等。
计算机中的处理器读取存储在计算机可读介质中的计算机可读程序代码，使得处理器能够执行在流程图中每个步骤、或各步骤的组合中规定的功能动作；生成实施在框图的每一块、或各块的组合中规定的功能动作的装置。
计算机可读程序代码可以完全在用户的计算机上执行、部分在用户的计算机上执行、作为单独的软件包、部分在用户的计算机上并且部分在远程计算机上，或者完全在远程计算机或者服务器上执行。也应该注意，在某些替代实施方案中，在流程图中各步骤、或框图中各块所注明的功能可能不按图中注明的顺序发生。例如，依赖于所涉及的功能，接连示出的两个步骤、或两个块实际上可能被大致同时执行，或者这些块有时候可能被以相反顺序执行。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本发明的范围。

Claims (21)

  1. 一种无源光网络PON的通信方法，其特征在于，所述PON包括光线路终端OLT和第一光网络单元ONU，所述方法包括：
    所述OLT通过一个下行波长λdx和所述第一ONU进行通信，所述一个下行波长λdx为N个下行波长λd1～λdN中的任意一个；
    所述OLT通过一个上行波长λu0和所述第一ONU进行通信，所述一个上行波长λu0与M个上行波长λu1～λuM中的任意一个均不相同；
    其中，所述N个下行波长λd1～λdN和所述M个上行波长λu1～λuM为第二ONU配置的波长值，N、M均为大于或等于2的整数，x为1～M中的任意一个值。
  2. 如权利要求1所述的方法，其特征在于，所述一个上行波长λu0所允许的中心波长的工作范围与M个上行波长λu1～λuM中任意一个所允许的中心波长的工作范围不同。
  3. 如权利要求1或2所述的方法，其特征在于，所述方法包括：
    所述OLT通过所述一个下行波长λdx向所述第一ONU发送注册消息；
    所述OLT通过所述一个上行波长λu0接收来自所述第一ONU的注册响应消息。
  4. 如权利要求1或2所述的方法，其特征在于，所述方法包括：
    所述OLT通过所述一个下行波长λdx向所述第一ONU发送时隙授权消息，所述时隙授权消息包括所述一个上行波长λu0的授权时隙；
    所述OLT通过所述一个上行波长λu0的授权时隙接收来自所述第一ONU的上行信号。
  5. 一种无源光网络PON的通信方法，其特征在于，所述PON包括光线路终端OLT和第一光网络单元ONU，所述方法包括：
    所述第一ONU通过一个下行波长λdx和所述OLT进行通信，所述一个下行波长λdx为N个下行波长λd1～λdN中的任意一个；
    所述第一ONU通过一个上行波长λu0和所述OLT进行通信，所述一个上行波长λu0与M个上行波长λu1～λuM中的任意一个均不相同；
    其中，所述N个下行波长λd1～λdN和所述M个上行波长λu1～λuM为第二ONU配置的波长值，N、M均为大于或等于2的整数，x为1～M中的任意一个值。
  6. 如权利要求5所述的方法，其特征在于，所述一个上行波长λu0所允许的中心波长的工作范围与M个上行波长λu1～λuM中任意一个所允许的中心波长的工作范围不同。
  7. 如权利要求5或6所述的方法，其特征在于，所述方法包括：
    所述第一ONU通过所述一个下行波长λdx接收来自所述OLT的注册消息；
    所述第一ONU通过所述一个上行波长λu0向所述OLT发送注册响应消息。
  8. 如权利要求5或6所述的方法，其特征在于，所述方法包括：
    所述第一ONU通过所述一个下行波长λdx接收来自所述OLT的时隙授权消息，所述时隙授权消息包括所述一个上行波长λu0的授权时隙；
    所述第一ONU通过所述一个上行波长λu0的授权时隙向所述OLT发送上行信号。
  9. 一种光线路终端OLT，应用于无源光网络PON，其特征在于，所述PON包括光线路终端OLT和第一光网络单元ONU，所述OLT包括：
    光发射器，用于通过一个下行波长λdx和所述第一ONU进行通信，所述一个下行波长λdx为N个下行波长λd1～λdN中的任意一个；
    光接收器，用于通过一个上行波长λu0和所述第一ONU进行通信，所述一个上行波长λu0与M个上行波长λu1～λuM中的任意一个均不相同；
    其中，所述N个下行波长λd1～λdN和所述M个上行波长λu1～λuM为第二ONU配置的波长值，N、M均为大于或等于2的整数，x为1～N中的任意一个值。
  10. 如权利要求9所述的OLT，其特征在于，所述一个上行波长λu0所允许的中心波长的工作范围与M个上行波长λu1～λuM中任意一个所允许的中心波长的工作范围不同。
  11. 如权利要求9或10所述的OLT，其特征在于，
    所述光发射器，用于通过所述一个下行波长λdx向所述第一ONU发送注册消息；
    所述光接收器，用于通过所述一个上行波长λu0接收来自所述第一ONU的注册响应消息。
  12. 如权利要求9或10所述的OLT，其特征在于，
    所述光发射器，用于通过所述一个下行波长λdx向所述第一ONU发送时隙授权消息，所述时隙授权消息包括所述一个上行波长λu0的授权时隙；
    所述光接收器，用于通过所述一个上行波长λu0的授权时隙接收来自所述第一ONU的上行信号。
  13. 一种光网络单元ONU，应用于无源光网络PON，其特征在于，所述PON包括光线路终端OLT和第一光网络单元ONU，所述ONU包括：
    光接收器，用于通过一个下行波长λdx和所述OLT进行通信，所述一个下行波长λdx为N个下行波长λd1～λdN中的任意一个；
    光发射器，用于通过一个上行波长λu0和所述OLT进行通信，所述一个上行波长λu0与M个上行波长λu1～λuM中的任意一个均不相同；
    其中，所述N个下行波长λd1～λdN和所述M个上行波长λu1～λuM为第二ONU配置的波长值，N、M均为大于或等于2的整数，x为1～M中的任意一个值。
  14. 如权利要求13所述的ONU，其特征在于，所述一个上行波长λu0所允许的中心波长的工作范围与M个上行波长λu1～λuM中任意一个所允许的中心波长的工作范围不同。
  15. 如权利要求13或14所述的ONU，其特征在于，
    所述光接收器，用于通过所述一个下行波长λdx接收来自所述OLT的注册消息；
    所述光发射器，用于通过所述一个上行波长λu0向所述OLT发送注册响应消息。
  16. 如权利要求13或14所述的ONU，其特征在于，所述方法包括：
    所述光接收器，用于所述一个下行波长λdx接收来自所述OLT的时隙授权消息，所述时隙授权消息包括所述一个上行波长λu0的授权时隙；
    所述光发射器，用于通过所述一个上行波长λu0的授权时隙向所述OLT发送上行信号。
  17. 一种计算机可读存储介质，包括指令，当其在计算机上运行时，使得计算机执行如权利要求1-4任意一项所述的方法。
  18. 一种计算机可读存储介质，包括指令，当其在计算机上运行时，使得计算机执行如权利要求5-8任意一项所述的方法。
  19. 一种包含指令的计算机程序产品，当其在计算机上运行时，使得计算机执行如权利要求1-4任意一项所述的方法。
  20. 一种包含指令的计算机程序产品，当其在计算机上运行时，使得计算机执行如权利要求5-8任意一项所述的方法。
  21. 一种无源光网络PON，其特征在于，所述PON包括如权利要求9-12任意一项所述的光线路终端OLT和如权利要求13-16任意一项所述的光网络单元ONU。
PCT/CN2017/072512 2017-01-24 2017-01-24 一种无源光网络pon的通信方法、装置和系统 WO2018137154A1 (zh)

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