CN105264853B - A kind of method, apparatus and system applied to passive optical network PON communication - Google Patents

Abstract

The embodiment of the present invention discloses a PON system supporting multi-protocol ONU registration, including an OLT and an ONU, the OLT is connected to a plurality of ONUs based on different MAC protocols and different rates through the ODN, and the OLT includes a plurality of MAC units, wherein , each of the MAC units is used for ONU registration based on different MAC protocols. Through the above technical solutions, when the PON system needs to be upgraded, there is no need to replace the OLT equipment, which can be upgraded smoothly and the upgrade cost can be saved. At the same time, the bandwidth can be increased on demand, and the utilization rate of the ODN is high, saving resources.

Description

A method, device and system applied to passive optical network PON communication

technical field

The invention relates to the technical field of network communication, in particular to a method, device and system applied to a passive optical network (PON).

Background technique

A passive optical network (Passive Optical Network, PON) consists of an optical line terminal (OpticalLine Terminal, OLT) on the office side, an optical network unit (Optical Network Unit, ONU) or an optical network terminal (Optical Network Terminal, ONT) on the user side, and Optical distribution network (Optical Distribute Network, ODN) composition. At present, representative PON technologies are GPON (Gigabit-Capable Passive Optical Network, Gigabit Passive Optical Network), EPON (Ethernet Passive Optical Network, Ethernet Passive Optical Network), 10G-GPON (also known as XG -PON), 10G-EPON.

The OLT provides a network-side interface for the PON system and connects to one or more ODNs. The ONU provides a user-side interface for the PON system and is connected to the ODN. If the ONU directly provides user port functions, such as an Ethernet user port for a personal computer (PC) to access the Internet, it is called an ONT. Unless otherwise specified, the ONU mentioned below collectively refers to ONU and ONT. ODN is a network composed of optical fibers and passive optical splitting devices, used to connect OLT equipment and ONU equipment, and used to distribute or multiplex data signals between OLT and ONU. In the PON system, from OLT to ONU is called downlink; conversely, from ONU to OLT is called uplink.

Orthogonal Frequency Division Multiplexing-Passive Optical Network (OFDM-PON) is a passive optical network based on OFDM technology, as shown in Figure 1. Because the MAC layers of OLT and ONU need to be used in pairs, and the MAC layer can only support a single protocol. For example, when the ONU of GPON only supports the GPON protocol, the MAC layer of the corresponding OLT can only support the GPON protocol, and the 10G-EPON OLT cannot be used with ONU communication of GPON or EPON, and so on, when the ONU only supports the EPON protocol, the MAC layer of the corresponding OLT can only support the EPON protocol. Therefore, when the existing PON system needs to support a variety of ONUs with different rates and different protocols in the face of upgrading requirements, the OLT equipment needs to be replaced, and the upgrading cost is relatively high.

Contents of the invention

In view of this, the embodiments of the present invention provide a method, device, and system applied to PON communication, which can solve the above-mentioned problem that OLT equipment needs to be replaced when the PON is upgraded, and the cost is high.

In the first aspect, a device applied to a passive optical network PON, the PON includes an optical line terminal OLT and a plurality of optical network units ONU, between the OLT and the plurality of ONUs based on orthogonal frequency division multiplexing Using OFDM to carry data, the device includes:

Multiple PON media access control MAC modules for coupling OFDM-based physical layer modules;

The multiple PON media access control MAC modules include a first PON MAC module and a second PONMAC module, the first PON MAC module and the second PON MAC module support different PON types, and the PON types include MAC protocols and at least one of PON link rates;

The first PON MAC module is associated to a first OFDM subchannel supported by the OFDM-based physical layer module;

The second PON MAC module is associated to the second OFDM sub-channel supported by the OFDM-based physical layer module, wherein the OFDM sub-carrier contained in the second OFDM sub-channel is the same as the OFDM sub-carrier contained in the first OFDM sub-channel. The OFDM subcarriers are different.

With reference to the first aspect, in a first possible implementation manner of the first aspect, a parameter interface module is further included, configured to transfer OFDM subchannel information between the OLT and the first ONU among the multiple ONUs.

With reference to the first possible implementation of the first aspect, in the second possible implementation of the first aspect, the OFDM subchannel information transmitted by the parameter interface module includes the first ONU allocated by the OLT to the first ONU. The channel information of the OFDM sub-channel, the PON type supported by the first ONU is consistent with the PON type of the first PON MAC module associated with the first OFDM sub-channel.

With reference to the second possible implementation of the first aspect, in a third possible implementation of the first aspect, the OLT allocates the first OFDM subchannel to the first ONU when at least one of the following conditions is met:

The OFDM sub-channel supported by the first ONU matches the sub-channel contained in the first OFDM sub-channel; the spectrum range supported by the first ONU matches the spectrum range of the first OFDM sub-channel; the PON type supported by the first ONU matches the first OFDM sub-channel. The PON types of the first PON MAC modules associated with the OFDM sub-channels are consistent; and the bandwidth capacity of the first OFDM sub-channel meets the bandwidth requirement of the first ONU.

With reference to any one of the first to third possible implementations of the first aspect, in a fourth possible implementation of the first aspect, the parameter interface module is configured to pass the physical layer negotiation process Passing channel information of multiple OFDM sub-channels supported by the OFDM-based physical layer module.

With reference to any one of the first to fourth possible implementations of the first aspect, in a fifth possible implementation of the first aspect, the OFDM subchannel information includes an OFDM channel identifier and an OFDM subcarrier at least one of the information.

In combination with the first aspect, and any one of the first to fifth possible implementations of the first aspect, in the sixth possible implementation of the first aspect, a management module is also included, configured to establish an ONU The association relationship with the OFDM sub-channel includes the association relationship between the first ONU and the first OFDM sub-channel.

With reference to the sixth possible implementation manner of the first aspect, in a seventh possible implementation manner of the first aspect, the association relationship represents a relationship between the ONU identifier and the channel information of the OFDM subchannel.

In combination with the first aspect, and any one of the first to seventh possible implementations of the first aspect, in an eighth possible implementation of the first aspect, the first OFDM subchannel and the The second OFDM sub-channel is a downlink sub-channel.

In combination with the first aspect, and any one of the first to eighth possible implementations of the first aspect, in the ninth possible implementation of the first aspect, the plurality of PON media access control MACs A module is a part of the OLT.

In the second aspect, an optical line terminal OLT is applied to a PON network, and the PON includes the OLT and a plurality of optical network units ONU; between the OLT and the plurality of ONUs based on orthogonal frequency division multiplexing OFDM carries data, and the OLT includes multiple PON MAC modules and OFDM-based physical layer modules,

Wherein, the multiple PON MAC modules are the devices described in the first aspect or any possible implementation manner of the first aspect;

The OFDM-based physical layer module is used to transmit the data of the first PON MAC module through the first OFDM sub-channel; transmit the data of the second PON MAC module through the second OFDM sub-channel.

With reference to the second aspect, in a first possible implementation of the second aspect, the physical layer module is configured to transmit the data of the first PON MAC module through the first OFDM subchannel, and transmit the data of the first PON MAC module through the second OFDM subchannel. The data of the two PON MAC modules, including:

The physical medium association module PMD module is used to receive the data of the first PON MAC module through the first OFDM sub-channel and modulate it into an OFDM signal; receive the data of the second PON MAC module through the second OFDM sub-channel and modulate it into an OFDM signal ;

A digital-to-analog converter for converting said OFDM signal into an analog electrical signal;

Optical transmitter: used to convert the analog electrical signal into an optical signal, and transmit the optical signal to the optical distribution network ODN;

A MAC adaptation module, configured to associate the first OFDM sub-channel with the first PON MAC module, and associate the second OFDM sub-channel with the second PON MAC module.

In the third aspect, a passive optical network PON system includes an optical line terminal OLT and a plurality of optical network units ONU; data is carried between the OLT and the plurality of ONUs based on OFDM; the The OLT is the OLT described in the second aspect and any possible implementation manner of the second aspect.

In a fourth aspect, a communication method applied to a PON, the PON includes an optical line terminal OLT and a plurality of optical network units ONU, between the OLT and the plurality of ONUs based on Orthogonal Frequency Division Multiplexing OFDM bearer data, the method comprising:

The OLT sends data information based on the first MAC protocol to the first ONU through the first OFDM downlink sub-channel, and the OLT sends data information based on the second MAC protocol to the second ONU through the second OFDM downlink sub-channel, wherein the The OFDM subcarriers included in the first OFDM subchannel are different from the subcarriers included in the second OFDM subchannel.

With reference to the fourth aspect, in a first possible implementation manner of the fourth aspect, the OLT sends OFDM subchannel information to the first ONU.

With reference to the fourth aspect, in a second possible implementation of the fourth aspect, the OLT allocates the first OFDM sub-channel to the first ONU when at least one of the following conditions is satisfied: the OFDM sub-channel supported by the first ONU The channel matches the subchannel contained in the first OFDM subchannel; the spectrum range supported by the first ONU matches the spectrum range of the first OFDM subchannel; the PON type supported by the first ONU matches the first PON associated with the first OFDM subchannel The PON types of the MAC modules are consistent; and the bandwidth capacity of the first OFDM sub-channel meets the bandwidth requirement of the first ONU.

With reference to the fourth aspect and the first or second possible implementation manner of the fourth aspect, the OLT sends the first uplink OFDM subchannel information allocated to the first ONU by the OLT to the first ONU.

With reference to the fourth aspect and any possible implementation manner of the fourth aspect, the OFDM subchannel information includes at least one of an OFDM channel identifier and OFDM subcarrier information.

In the fifth aspect, an ONU registration method is applied in a PON network, and the PON includes an optical line terminal OLT and a plurality of optical network units ONU; between the OLT and the plurality of ONUs, based on orthogonal frequency division Multiplexing OFDM bearer data, the method includes:

The OLT sends a registration request message with a first MAC protocol through the first OFDM subchannel;

The OLT sends a registration request message with the second MAC protocol through the second OFDM sub-channel, wherein the OFDM sub-carriers included in the first OFDM sub-channel are different from the OFDM sub-carriers included in the first OFDM sub-channel; The MAC protocol is a MAC protocol associated with the first OFDM subchannel, the second MAC protocol is a MAC protocol associated with the second OFDM subchannel, and the first MAC protocol is different from the second MAC protocol;

The OLT receives the registration request response message from the ONU, judges whether the ONU is legal, and if legal, allocates an ONU identifier for the ONU, performs ranging for the ONU, allocates OFDM sub-channels for the ONU, and establishes an ONU identifier Association with the OFDM subchannel.

With reference to the fifth aspect, in a first possible implementation of the fifth aspect, the OLT sends physical layer configuration parameters related to the first OFDM subchannel with the first MAC protocol on the first OFDM subchannel;

The OLT sends physical layer configuration parameters related to the second OFDM sub-channel through the second MAC protocol on the second OFDM sub-channel, wherein the physical layer configuration parameters include at least one of OFDM channel identifier and OFDM sub-carrier information.

With reference to the fifth aspect, in a second possible implementation of the fifth aspect, assigning OFDM sub-channels to the ONU includes:

Assign OFDM sub-channels for the ONU, including:

When at least one of the following conditions is satisfied, the OLT allocates the third OFDM subchannel to the first ONU:

The OFDM sub-channel supported by the first ONU matches the sub-channel contained in the third OFDM sub-channel; the spectrum range supported by the first ONU matches the spectrum range of the third OFDM sub-channel; the PON type supported by the first ONU matches that of the third OFDM sub-channel The PON types of the first PON MAC modules associated with the OFDM sub-channel are consistent; and the bandwidth capacity of the third OFDM sub-channel meets the bandwidth requirement of the first ONU.

With reference to the second possible implementation manner of the fifth aspect, in a third possible implementation manner of the fifth aspect, the method further includes:

When the third OFDM sub-channel is different from the first OFDM sub-channel, the OLT performs a second ranging on the ONU.

With reference to the third possible implementation manner of the fifth aspect, in a fourth possible implementation manner of the fifth aspect, the method further includes:

After the OLT allocates a new OFDM subchannel to the ONU, the OLT delivers the default bit bearing table to the ONU.

With reference to the fourth possible implementation of the fifth aspect, in the fifth possible implementation of the fifth aspect, the method further includes:

The OLT sends a downlink training sequence to the ONU through the third OFDM downlink subchannel;

The OLT receives the downlink bit value of the ONU through the third OFDM downlink sub-channel, generates the updated bit bearing table and sends the updated bit bearing table to the ONU;

The OLT performs ranging for the ONU for the third time.

In a sixth aspect, an OLT includes:

A memory for storing the mapping relationship information between each of the downlink subchannels and the MAC protocol;

The first media access control MAC module is used to send a registration request message with the first MAC protocol through the first OFDM sub-channel; receive a registration request response message from the first ONU, judge whether the first ONU is legal, and if legal The first ONU distributes the ONU mark; The first ONU is ranged, and the OFDM sub-channel is allocated for the first ONU;

The second MAC module is used to send a registration request message with the second MAC protocol through the second OFDM sub-channel; receive a registration request response message from the second ONU, and judge whether the second ONU is legal, and if legal, it is the second ONU Assigning an ONU identification; performing ranging on the second ONU, and assigning OFDM sub-channels to the second ONU;

Wherein, the OFDM subcarrier contained in the first OFDM subchannel is different from the OFDM subcarrier contained in the first OFDM subchannel; the first MAC protocol is a MAC protocol associated with the first OFDM subchannel, and the second MAC the protocol is a MAC protocol associated with the second OFDM subchannel, and the first MAC protocol is different from the second MAC protocol;

The physical medium is associated with the PMD module, which is used to associate the first OFDM subchannel to the first PON MAC module, and the second OFDM subchannel to the second PON MAC module; in the downlink direction, the first PON MAC module is received through the first OFDM subchannel The data of the second PON MAC module is modulated into an OFDM signal; the data of the second PON MAC module is received through the second OFDM sub-channel, and modulated into an OFDM signal;

A MAC adaptation module, one end is coupled to the PMD module, and one end is coupled to the first MAC module and/or the second MAC module, for when receiving an ONU upstream optical signal, according to the bandwidth allocation bitmap BWmap, the The OFDM signal demodulated by the PMD module is sent to the first MAC module or the second MAC module.

In a first possible implementation manner of the sixth aspect, the first MAC module is further configured to send physical layer configuration parameters related to the first OFDM subchannel by using the first MAC protocol through the first OFDM subchannel.

In a second possible implementation of the sixth aspect, the first MAC module is configured to assign a downlink subchannel to the first ONU, specifically including:

When the spectrum range supported by the ONU type does not match the first OFDM sub-channel; or, the ONU type does not match the MAC protocol carried by the first OFDM sub-channel; or, the bandwidth capacity of the first OFDM sub-channel does not match Can satisfy the bandwidth requirement of the first ONU, distribute the 3rd OFDM sub-channel to the first ONU, wherein, the 3rd OFDM sub-channel meets the following conditions:

The spectrum range supported by the first ONU matches the spectrum range of the third OFDM sub-channel; the PON type supported by the first ONU is consistent with the PON type of the first PON MAC module associated with the third OFDM sub-channel; and the third OFDM sub-channel The bandwidth capacity of meets the bandwidth requirement of the first ONU.

In a third possible implementation of the sixth aspect, the first MAC module is further configured to perform a second test on the first ONU after the OLT allocates the third OFDM subchannel to the first ONU. distance.

In a fourth possible implementation of the sixth aspect, the first MAC module is further configured to perform a third test on the first ONU after the OLT sends the updated bit bearing table to the ONU. distance.

In the seventh aspect, an optical line terminal OLT includes: a processor, a memory, a bus, and a communication interface; the memory is used to store computer-executable instructions, the processor and the memory are connected through the bus, and when the When the computer is running, the processor executes the computer-executable instructions stored in the memory, so that the computer executes the method according to the fifth aspect and any possible implementation manner of the fifth aspect.

The present invention proposes a novel PON system, equipment and a method for supporting multi-protocol ONU registration. When the PON system is required to be upgraded, there is no need to replace the OLT equipment, and the upgrade can be performed smoothly, saving the upgrade cost.

Description of drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the drawings used in describing the background technology and the embodiments. Obviously, what is described in the following drawings is only a part of the embodiments of the present invention, and those skilled in the art can obtain other drawings or embodiment, and the present invention is intended to cover all such derivative figures or embodiments.

FIG. 1 is a schematic diagram of a PON network architecture;

Fig. 2a is a block diagram of a device applied to a passive optical network PON provided by Embodiment 1 of the present invention;

FIG. 2b is a structural diagram of another device module applied to a passive optical network PON provided by Embodiment 1 of the present invention;

3 is a schematic structural diagram of an optical line terminal OLT provided by Embodiment 2 of the present invention;

FIG. 4 is a schematic structural diagram of a passive optical network PON provided by Embodiment 3 of the present invention;

5 is a schematic structural diagram of an ONU provided by Embodiment 3 of the present invention;

6 is a schematic structural diagram of another ONU provided in Embodiment 3 of the present invention;

FIG. 7 is a flowchart of a communication method applied to PON provided by Embodiment 4 of the present invention;

FIG. 8 is a flow chart of a method for ONU registration provided in Embodiment 5 of the present invention;

FIG. 9a is a flow chart of another ONU registration method provided in Embodiment 5 of the present invention;

FIG. 9b is an interactive schematic diagram of an ONU registration provided in Embodiment 5 of the present invention;

FIG. 9c is another schematic diagram of ONU registration interaction provided by Embodiment 5 of the present invention;

FIG. 9d is another schematic diagram of ONU registration interaction provided by Embodiment 5 of the present invention;

FIG. 10 is a schematic structural diagram of an optical line terminal OLT provided in Embodiment 6 of the present invention;

FIG. 11 is a schematic structural diagram of an optical line terminal OLT provided by Embodiment 7 of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Embodiment one

Orthogonal Frequency Division Multiplexing (OFDM-PON) is a passive optical network based on OFDM technology. OFDM technology belongs to multi-carrier modulation technology. Its basic idea is to divide the channel into several frequency-orthogonal sub-channels, convert high-speed data signals into parallel low-speed sub-data streams, and modulate them on each sub-channel for transmission. In the OFDM-PON system, there is only one wavelength in the uplink and downlink directions. In the downlink direction, the MAC (Media Access Control, Media Access Control) module of the OLT is used to implement functions such as ONU management, DBA (Dynamic Bandwidth Allocation, dynamic bandwidth allocation), ONU registration activation, and data transmission and reception; the physical layer includes PMD ( Physical Medium Dependent, physical medium association layer), DAC (Digital-to-Analog Converter, digital-to-analog converter) ADC (Analog-to-Digital Converter, analog-to-digital converter), optical transmitter, optical receiver and other hardware devices, among which , the PMD module is used to modulate the data output by the MAC module into an OFDM signal, the DAC is used to convert the OFDM signal in the digital domain into an analog electrical signal, and the optical transmitter Tx is used to convert the electrical signal into an optical signal and transmit it to the optical distribution Network ODNs. The optical signal is transmitted to the ONU through the ODN network. The optical receiver Rx of the ONU is used to receive the optical signal and convert the optical signal into an electrical signal. The analog-to-digital converter ADC is used to convert the analog electrical signal into a digital signal, which is realized by the PMD module. For demodulation of OFDM signals, the demodulated signals are transmitted to the MAC module for processing. In the upstream direction, the MAC module of the ONU is used to implement functions such as ONU management, DBA, and data transmission. The functions of the PMD, DAC, Tx, Rx, and ADC modules are similar to those described in the downstream direction, and will not be repeated here.

As shown in Figure 2a and Figure 2b, the embodiment of the present invention discloses a device 200 applied to a passive optical network PON, the PON includes an optical line terminal OLT and a plurality of optical network units ONU, between the OLT and the Orthogonal frequency division multiplexing OFDM bears data between multiple ONUs, and the device includes:

Multiple PON media access control MAC modules for coupling OFDM-based physical layer modules;

The multiple PON media access control MAC modules include a first PON MAC module and a second PON MAC module, the first PON MAC module and the second PON MAC module support different PON types, and the PON type includes a MAC protocol and at least one of PON link rate;

The first PON MAC module is associated to a first OFDM subchannel supported by the OFDM-based physical layer module;

The second PON MAC module is associated to the second OFDM sub-channel supported by the OFDM-based physical layer module, wherein the OFDM sub-carrier contained in the second OFDM sub-channel is the same as the OFDM sub-carrier contained in the first OFDM sub-channel. The OFDM subcarriers are different.

Optionally, the MAC protocol includes GPON protocol, EPON protocol, 10G-GPON protocol, 10G-EPON protocol, or MAC protocol with higher transmission rate such as 40G-PON, 100G-PON, or Ethernet protocol, CPRI (Common One of MAC protocols such as PublicRadio Interface, OBSAI (Open Base Station Architecture Initiative, Open Base Station Architecture Protocol).

Optionally, the first PON MAC module and the second PON MAC module may be integrated together.

Optionally, the first OFDM sub-channel and the second OFDM sub-channel divide downlink channels into subcarrier groups. For example, the downlink OFDM signal has a total of 1024 subcarriers, which are assumed to be divided into 4 subchannels, each subchannel occupies 256 subcarriers, and the IDs of the subchannels are 0-3 respectively.

Optionally, the first OFDM sub-channel and the second OFDM sub-channel divide the downlink channel according to the frequency spectrum of the downlink OFDM signal. For example, the frequency spectrum of the downlink OFDM signal is 1 GHz, and it is assumed that it is divided into 4 sub-channels, and each sub-channel occupies a spectrum resource of 250 MHz, and the IDs of the sub-channels are 0-3 respectively.

Optionally, the device further includes a parameter interface module, configured to transfer OFDM subchannel information between the OLT and the first ONU among the plurality of ONUs. Wherein, the OFDM sub-channel information includes the channel information of the first OFDM sub-channel allocated by the OLT to the first ONU, the PON type supported by the first ONU and the first PON MAC associated with the first OFDM sub-channel The PON types of the modules are the same. For example, the first PON MAC module supports the GPON protocol, the first OFDM sub-channel supports the GPON protocol, and the first ONU corresponding to the first OFDM sub-channel supports the GPON protocol; the second PON MAC module supports the EPON protocol, and the second OFDM sub-channel supports the GPON protocol. The subchannel supports the EPON protocol, and the second ONU corresponding to the subchannel supports the EPON protocol.

The device also includes: when any of the following conditions is met, assigning the first OFDM subchannel to the first ONU, the conditions including:

The spectrum range supported by the first ONU matches the spectrum range of the first OFDM sub-channel; the PON type supported by the first ONU is consistent with the PON type of the first PON MAC module associated with the first OFDM sub-channel; and the first OFDM sub-channel The bandwidth capacity of meets the bandwidth requirement of the first ONU.

Optionally, the parameter interface module is configured to transmit channel information of multiple OFDM sub-channels supported by the OFDM-based physical layer module through the physical layer negotiation process.

Wherein, the OFDM sub-channel information includes at least one of OFDM channel identifier and OFDM sub-carrier information.

Optionally, the device further includes a management module, configured to establish an association relationship between an ONU and an OFDM subchannel, including an association relationship between a first ONU and a first OFDM subchannel. The association relationship represents the relationship between the ONU identifier and the channel information of the OFDM sub-channel.

Optionally, the first OFDM sub-channel and the second OFDM sub-channel are downlink sub-channels.

Optionally, the first OFDM sub-channel and the second OFDM sub-channel are respectively an uplink OFDM sub-channel and a downlink OFDM sub-channel, or are respectively a downlink OFDM sub-channel and an uplink OFDM sub-channel.

Optionally, the multiple PON media access control MAC modules are part of the OLT.

The first PON MAC module or the second PON MAC module may use a Field-Programmable Gate Array (Field-Programmable Gate Array, FPGA), may use an Application Specific Integrated Circuit (ASIC), or may use a system chip ( System on Chip, SoC), can also use a central processing unit (Central Processor Unit, CPU), can also use a network processor (Network Processor, NP), can also use a digital signal processing circuit (Digital Signal Processor, DSP), or A microcontroller (Micro Controller Unit, MCU) may be used, and a programmable controller (Programmable Logic Device, PLD) or other integrated chips may also be used.

Embodiment two

The embodiment of the present invention discloses an optical line terminal OLT, as shown in FIG. 3 , which is applied to a passive optical network PON. Orthogonal frequency division multiplexing OFDM is used to carry data between them, and the OLT includes multiple PON MAC modules and OFDM-based physical layer modules.

Wherein, the PON MAC module includes the device described in Embodiment 1;

The multiple PON MAC modules are coupled to the OFDM-based physical layer module, and the OFDM-based physical layer module is used to transmit the data of the first PON MAC module through the first OFDM sub-channel; transmit through the second OFDM sub-channel Data of the second PON MAC module.

Specifically, the physical layer module includes:

The physical medium is associated with the PMD module, which is used in the downlink direction, receives the data of the first PON MAC module through the first OFDM sub-channel, and modulates it into an OFDM signal; receives the data of the second PON MAC module through the second OFDM sub-channel, and modulates it into OFDM signal; in the uplink direction, it receives the digital baseband OFDM signal sent by the analog-to-digital converter, and demodulates the data signal that the MAC can process.

It is worth noting that in OFDM-PON, the ONU upstream uses Time Division Multiple Access (TDMA) to transmit data. The OLT will allocate a small amount of bandwidth for the ONU to report its bandwidth requirements, such as the length or size of the data buffer to be sent. After receiving it, the OLT will calculate the bandwidth authorization size allocated to the ONU, and use the bandwidth allocation bitmap (BandWidth Map, BWmap ) or other forms to the ONU, indicating the start time and length information of the uplink time slot authorized to the ONU. When the ONU receives the BWmap, it will emit light in the corresponding uplink time slot according to the timing of the BWmap, and send the uplink data to the OLT.

Wherein, the PON MAC module is configured to allocate BWmaps to ONUs supporting the same MAC protocol as the PON MAC respectively. For example, the MAC module supporting the GPON protocol allocates BWmap to the ONU supporting the GPON protocol, and the MAC module supporting the EPON protocol allocates BWmap to the ONU supporting the EPON protocol.

A digital-to-analog converter for converting said OFDM signal into an analog electrical signal;

an optical transmitter, configured to convert the analog electrical signal into an optical signal, and transmit the optical signal to an optical distribution network ODN.

A MAC adaptation module, one end is coupled to each of the PON MAC modules, and one end is coupled to the PMD module, for associating the first OFDM sub-channel to the first PON MAC module, and the second OFDM sub-channel to the second PON MAC module; when receiving an uplink optical signal, according to the BWmap, determine the PON MAC module corresponding to the ONU sending the signal at this moment, and send the data signal demodulated by the PMD module to the corresponding PON MAC module.

The physical layer module also includes an analog-to-digital converter and an optical receiver, wherein the optical receiver is used to receive the upstream optical signal sent from the ONU, and convert the optical signal into an analog electrical signal; the analog-to-digital converter is used to convert the analog electrical signal The signal is converted to a digital signal and sent to the PMD module.

Embodiment three

The embodiment of the present invention discloses a passive optical network PON, as shown in FIG. 4 , including an OLT and a plurality of ONUs, and the OLT and the ONUs carry data based on OFDM, and the OLT Can support a variety of MAC protocols, such as GPON, EPON, 10G-GPON or 10G-EPON, and future development of higher-speed 40G-PON, 100G-PON protocols, or Ethernet protocols, CPRI protocols, OBSAI and other MAC protocols one or more of. Correspondingly, the multiple ONUs support one of GPON, EPON, 10G-GPON or 10G-EPON, Ethernet protocol, CPRI protocol, OBSAI and other protocols, and there are at least two MAC protocols in the PON system.

In the PON system described in Figure 4, the downlink channel is divided into multiple sub-channels according to the frequency spectrum of the downlink analog OFDM signal or sub-carriers. Taking 1GHz as an example, it is divided into 4 sub-channels, and each sub-channel occupies 250MHz of spectrum resources. The ID of the sub-channel can be 0-3.

Preferably, the ONUs with similar SNRs can be assigned to the same sub-channel, and the sub-channels where the ONUs with higher SNRs are located can have higher requirements for modulating downlink signals, thereby increasing the total bandwidth of the downlink channel.

Optionally, GPON or EPON ONU can choose to support 250MHz low-frequency analog devices and optical devices, OLT or 10G-GPON, 10G-EPON ONU can choose to support 1GHz spectrum high-frequency analog devices and optical devices.

The OLT includes the OLT as described in the second implementation;

The multiple ONUs are used to receive downlink optical signals from the ODN, and transmit uplink data to the OLT in a TDMA manner.

The ONU specifically includes:

The optical receiver is used to receive the optical signal transmitted by the ODN and convert it into an analog electrical signal;

An analog-to-digital converter DAC for converting an analog electrical signal into a digital baseband signal;

The PMD module is used to demodulate the digital baseband signal to form a data signal that can be processed by the MAC module;

The MAC module is used to receive and process the data of the PMD module.

It should be noted that when the OLT modulates the OFDM signal, it converts the signal in the frequency domain into a signal in the time domain; when the ONU receives it, it demodulates the OFDM signal and converts the signal in the time domain into a signal in the frequency domain.

Specifically, there are two implementation schemes for the hardware structure of the ONU, as shown in Figure 5. The first scheme adopts the scheme of direct detection. Implementation of 10G-EPON.

The second is to adopt the scheme of coherent reception in the electrical domain, as shown in Figure 6, adjust the frequency of the local oscillator (Local Oscillator, LO) to align with the center frequency of the downlink spectrum, and can receive the OFDM of the sub-channel whose center frequency is consistent with the center frequency The signal can be used in the ONU implementation scheme of EPON and GPON.

It should be noted that the OLT needs to transmit the information of the sub-channel corresponding to the first ONU in advance, such as the identification ID of the sub-channel or the frequency range of the sub-channel, etc., so that the first ONU can adjust the frequency of the LO to the sub-channel and receive Signal. The prior notification may be sending the association relationship information between the ONU and the subchannel to the ONU through a message, or configuring the association relationship information locally on the ONU, or using other methods in the prior art, which will not be repeated here.

Both the direct detection scheme and the electrical domain coherent reception scheme are existing technologies, and will not be described in detail here.

For clarity of description, for example, the ONU supporting GPON is called the first ONU, the ONU supporting EPON is called the second ONU, and the ONU supporting 10G-GPON is called the third ONU.

The first ONU adopting the first type of direct detection receives the OFDM signal, demodulates and extracts the corresponding MAC data signal. According to Embodiment 1, the first PON MAC module is associated with the first OFDM subchannel, and the first MAC protocol is the GPON protocol, then the ONU receives the data signal of the first subchannel, that is, the first subchannel is bound with the GPON protocol.

Using the first ONU of the second type of electrical domain coherent reception, the frequency of the LO is adjusted to be aligned with the center frequency of the downlink spectrum, and the OFDM signal of the sub-channel aligned with the center frequency can be fixedly received and the data signal is demodulated.

The third ONU adopting the first solution needs to support receiving and processing OFDM signals of all or multiple sub-channels in order to achieve a larger bandwidth, that is, to bind multiple sub-channels into one downlink channel.

Embodiment Four

The embodiment of the present invention discloses a communication method applied to PON. The method is applied to the PON system described in Embodiment 3. As shown in FIG. 7, the PON includes an optical line terminal OLT and a plurality of optical network units ONU, Bearing data based on OFDM between the OLT and the plurality of ONUs, the method includes:

The OLT sends data information based on the first MAC protocol to the first ONU through the first OFDM downlink sub-channel, and the OLT sends data information based on the second MAC protocol to the second ONU through the second OFDM downlink sub-channel, wherein the The OFDM subcarriers included in the first OFDM subchannel are different from the subcarriers included in the second OFDM subchannel.

Optionally, the method also includes:

The OLT sends the first downlink OFDM subchannel information allocated to the first ONU by the OLT to the first ONU.

Optionally, the method also includes:

The OLT allocates the first OFDM subchannel to the first ONU when at least one of the following conditions is met: the spectrum range supported by the first ONU matches the spectrum range of the first OFDM subchannel; the PON type supported by the first ONU matches the spectrum range of the first ONU The PON types of the first PON MAC modules associated with an OFDM sub-channel are consistent; and the bandwidth capacity of the first OFDM sub-channel meets the bandwidth requirement of the first ONU.

Optionally, the method also includes:

The OFDM sub-channel information includes at least one of an OFDM channel identifier and OFDM sub-carrier information.

It should be noted that the uplink of the ONU adopts the mode of time division multiple access TDMA. The implementation process is as follows:

When the OLT performs OFDM modulation, it converts the signal in the frequency domain into the time domain through the inverse Fourier transform method and sends it to the ONU;

The ONU receiving end receives the subcarriers of different frequencies in chronological order, and converts the time domain signal into a frequency domain signal through the Fourier transform method, and each ONU receives corresponding data from the corresponding OFDM subchannel. When upstream, report to the OLT according to the time division multiple access TDMA method.

There is only one wavelength in the upstream, and ONUs with different MAC protocols access the OLT in TDMA mode. There are two methods for the PMD module of the OLT to demodulate the upstream OFDM signal: one is to switch the demodulation parameters according to the BWmap (Bandwidth Map, bandwidth allocation bitmap) information ( Such as the upstream B table, equalization coefficient table, etc.), demodulate the upstream data of the corresponding ONU, and then forward it to the PONMAC module corresponding to the ONU (the forwarding function can also be realized by the MAC adaptation module of the MAC layer); the second is that all ONUs Uplink uses the same demodulation parameters to demodulate uplink data, and the MAC adaptation module at the MAC layer forwards it to the PONMAC module corresponding to the ONU according to the BWmap information.

Specifically, the BWmap includes the description information of the ONU uplink time slot, and the BWmap is sent to the ONU by the OLT, and the OLT can also adjust the PMD layer parameters in advance according to the BWmap to prepare for receiving uplink data; in addition, the Alloc-ID can obtain the corresponding ONU-ID, the upstream data frame includes the ONU-ID, after the MAC receives the upstream data, it can compare the ONU-ID field to check whether the two are consistent, and can also compare the receiving time of the ONU upstream data with the authorization time in the BWmap. Determine whether the timing of the ONU is normal. This solution is a prior art, and will not be repeated here.

Embodiment five

Fig. 8 shows a flow chart of a method for ONU registration provided by an embodiment of the present invention, which is applied in a PON network, and the PON network includes an optical line terminal OLT and a plurality of optical network units ONU; between the OLT and the Orthogonal frequency division multiplexing OFDM bears data between a plurality of ONUs, as shown in Figure 8, the method includes:

S800, the OLT sends a registration request message through the first OFDM subchannel with the first MAC protocol;

S802. The OLT sends a registration request message using the second MAC protocol through the second OFDM subchannel, wherein the OFDM subcarriers included in the first OFDM subchannel are different from the OFDM subcarriers included in the first OFDM subchannel;

S804. The OLT receives the registration request response message from the ONU, allocates an ONU identifier and an OFDM subchannel to the ONU judged to be legal, and establishes an association between the allocated ONU identifier and the OFDM subchannel. The OLT judges whether the ONU is a legal ONU according to the serial number of the ONU.

Optionally, the method further includes: the OLT sends physical layer configuration parameters related to the first OFDM subchannel with the first MAC protocol on the first OFDM subchannel;

The OLT sends physical layer configuration parameters related to the second OFDM sub-channel through the second MAC protocol on the second OFDM sub-channel, wherein the physical layer configuration parameters include at least one of OFDM channel identifier and OFDM sub-carrier information.

Specifically, allocate OFDM sub-channels for the ONU, including:

When the spectrum range supported by the ONU type does not match the first OFDM sub-channel; or, the ONU type does not match the MAC protocol carried by the first OFDM sub-channel; or, the bandwidth capacity of the first OFDM sub-channel does not match When the bandwidth requirement of the first ONU can be satisfied, the third OFDM sub-channel is allocated to the first ONU, wherein the third OFDM sub-channel meets one of the following conditions:

The spectrum range supported by the first ONU matches the spectrum range of the third OFDM sub-channel; the PON type supported by the first ONU is consistent with the PON type of the first PON MAC module associated with the third OFDM sub-channel; and the third OFDM sub-channel The bandwidth capacity of meets the bandwidth requirement of the first ONU.

It should be noted that the ONU registration response request message carries the ONU serial number and can also carry the ONU type; the ONU can also report the ONU type separately through other messages, such as Physical Layer Operation Administration Management (PLOAM) information.

The method also includes the OLT allocating the third OFDM downlink sub-channel to the ONU, and when the third OFDM sub-channel is different from the first OFDM sub-channel, the OLT performs a second ranging on the ONU .

Wherein, the downlink sub-channel for the ONU to receive the registration message is selected by the ONU itself, not allocated by the OLT. If the sub-channel selected by the ONU conforms to the OLT's principle of allocating downstream sub-channels, the OLT formally allocates the sub-channel to the ONU, otherwise allocates other downstream sub-channels to the ONU.

Furthermore, the principles for the OLT to allocate official downlink sub-channels include: whether the PON protocol type of the sub-channel is consistent, whether the bandwidth capacity of the sub-channel meets the requirements of the ONU, and whether the operator ID is consistent (in one scenario, the downlink sub-channel is bound to the operator, Only the ONUs of the operator can access), load balancing considerations between downlink sub-channels, considerations for traffic scheduling between sub-channels (for example, to save energy, concentrate ONUs on some downlink sub-channels when there are fewer ONUs), etc.

The method further includes that after the OLT allocates the third OFDM sub-channel to the ONU, the ONU reports the updated downlink bit bearing table to the OLT.

It should be noted that, the OLT and the ONU determine the PMD layer working parameters of the sub-channels through the default bit-carrying table B or the updated bit-carrying table B.

By default, the technology in Table B is the prior art, please refer to the relevant records of the prior art, and will not repeat them here.

Before the ONU reports the updated downlink bit bearing table to the OLT, it also includes: the OLT sends a downlink training sequence to the ONU through the third OFDM downlink sub-channel; the ONU sends the downlink training sequence to the ONU through the third OFDM The OFDM downlink sub-channel receives the downlink training sequence, and calculates and generates the updated downlink bit bearing table; the ONU sends the updated downlink bit bearing table to the OLT.

The method further includes that after the OLT allocates the third OFDM sub-channel to the ONU, the OLT sends the updated uplink bit bearing table to the ONU.

Before the OLT sends the updated uplink bit bearing table to the ONU, it also includes: the ONU sends an uplink training sequence to the OLT; the OLT receives the uplink training sequence through the OFDM uplink channel, and calculates generating the updated uplink bit bearing table; the OLT sending the updated uplink bit bearing table to the ONU through the downlink OFDM sub-channel.

The method further includes the OLT performing a third ranging on the ONU.

The following describes the embodiment of the present invention in combination with specific application scenarios. FIG. 9a is a flow chart of an ONU registration method provided by the embodiment of the present invention. Figures, as shown in Figures 9a, 9b, 9c, 9d.

In the PON network, the optical line terminal OLT is connected to a plurality of optical network units ONUs with different passive optical network MAC protocols through the optical distribution network ODN, and the optical line terminal OLT is provided with mappings between M downlink sub-channels and N types of MAC protocols Relationship information, where M and N are both integers greater than or equal to 1. Said setting may be that the mapping relationship information is stored in the memory RAM or ROM of the OLT, flash memory, registers, etc., or directly write the mapping relationship information into the chip, or by configuring the command line or The network management system is set on the OLT by means of external input.

S900. The OLT acquires a correspondence between each downlink subchannel and a MAC protocol, where the first subchannel corresponds to the first MAC protocol.

Wherein, the mapping relationship information between the M downlink sub-channels and the MAC protocol may be shown in Table 1 below:

Table 1 Mapping relationship table between downlink sub-channel and MAC protocol

Subchannel ID MAC protocol 0 GPON 1 EPON 2 10G-GPON 3 10G-EPON

As shown in Table 1, the sub-channel with ID 0 corresponds to the GPON protocol one-to-one, the sub-channel with ID 1 corresponds to the EPON protocol one-to-one, the sub-channel with ID 2 corresponds to the 10G-GPON protocol one-to-one, and the ID is 3 The sub-channels correspond to the 10G-EPON protocol one by one.

Further, the M downlink sub-channels may be divided into multiple sub-channels according to the frequency spectrum of the downlink OFDM signal. In this embodiment, taking the frequency spectrum of the OFDM signal as 1 GHz as an example, it is assumed that it is divided into 4 sub-channels (of course, it can also be divided into other multiple sub-channels), and each sub-channel occupies a spectrum resource of 250 MHz. The 4 sub-channels The channel IDs are set to 0~3 respectively.

Further, it is assumed that the frequency spectrum of 1 GHz can support a data transmission rate of 10 Gbps. For GPON, usually the downlink data transmission rate is 2.5Gbps, and the uplink data transmission rate is 1.25Gbps. For EPON, the uplink and downlink data transmission rates are usually 1.25Gbps, so G/E-PON (collectively referred to as GPON and EPON) only needs to occupy less spectrum resources, assuming that the spectrum allocated for G/E-PON is 250MHz. For 10G-GPON, usually the downlink data transmission rate is 10Gbps, and the uplink data transmission rate is 2.5Gbps. Asymmetric 10G-EPON, the downlink data transmission rate is 10Gbps, and the uplink data transmission rate is 1.25Gbps, so the downlink of 10G-PON (collectively referred to as downlink 10Gbps PON, including 10G-GPON and 10G-EPON) needs 1GHz spectrum.

Further, the M downlink sub-channels may divide the downlink channel into multiple sub-channels according to the frequency spectrum of the downlink OFDM signal. In this embodiment, taking the frequency spectrum of the OFDM signal as 1 GHz as an example, it is assumed that it is divided into 4 sub-channels (of course, it can also be divided into other multiple sub-channels), and the IDs of the 4 sub-channels are respectively set to 0-3 .

The ONU of OLT and 10G-PON needs to select high-frequency analog devices and optical devices that support 1GHz spectrum. The analog devices include digital-to-analog converters DAC and analog-to-digital converters ADC, etc.; the optical devices include optical transmitters and optical receivers. The ONU of G/E-PON can also adopt this type of ONU, and then allocate sub-channels of corresponding bandwidth to it.

Preferably, according to the above-mentioned downlink spectrum requirements, the ONU of the G/E-PON can select low-frequency analog devices and optical devices that support 250MHz spectrum. For the ONU of the first scheme, the analog device includes a low-pass electric filter and an analog-to-digital converter ADC, a digital-to-analog converter DAC, etc.; for the ONU of the second scheme, the analog device includes a band-pass electric filter, this oscillator LO, analog-to-digital converter ADC or IQ demodulator (In-phase and Quadrature Modulator), digital-to-analog converter DAC; the optical device includes an optical receiver.

Obviously, with the optimal solution, the cost of G/E-PON ONUs can be lower than that of 10G-PON ONUs. Therefore, choosing appropriate analog devices and optical devices for ONUs of different PONs can effectively reduce costs.

Step S901: the OLT sends a registration request message through the first OFDM sub-channel with the first MAC protocol;

For ease of understanding, the GPON protocol corresponding to the subchannel ID of 0 in Table 1 is taken as an example for the first MAC protocol. The OLT reads the mapping relationship information in Table 1, and according to the mapping relationship information, sends the first ONU registration request message to the first ONU through the sub-channel whose ID is 0; wherein, the first ONU supports the GPON protocol The ONU.

Specifically, the frame format of the first ONU registration request message may adopt the frame format of the ONU registration request message issued by the OLT in the GPON system in the prior art, or other self-defined frame formats. Regarding the GPON system in the prior art, the frame format of the ONU registration request message is the prior art, and will not be repeated here.

Further, before the OLT periodically starts the ONU registration process and sends the registration request message with the first MAC protocol, it can also send the first ONU to work normally through the first sub-channel of the M sub-channels through the default downstream bit bearing table. The required physical layer parameters describe the message, and the quiet window is opened on the uplink channel.

Step 902: The OLT sends a registration request message with the second MAC protocol through the second OFDM sub-channel;

For ease of understanding, the EPON protocol corresponding to the subchannel ID of 1 in Table 1 is used as an example for the second MAC protocol. The OLT reads the mapping relationship information in Table 1, and according to the mapping relationship information, sends the second ONU registration request message to the second ONU through the sub-channel whose ID is 1; wherein, the second ONU supports the EPON protocol The ONU.

Specifically, the frame format of the second ONU registration request message may adopt the frame format of the ONU registration request message sent by the OLT in the EPON system in the prior art, or other self-defined frame formats. Regarding the EPON system in the prior art, the frame format of the ONU registration request message is the prior art, and will not be repeated here.

Further, before the OLT periodically starts the ONU registration process and sends the registration request message with the second MAC protocol through the default downlink bit bearing table, it can also send the second ONU to work normally through the second sub-channel of the M sub-channels. The required physical layer parameters describe the message, and the quiet window is opened on the uplink channel.

As shown in 9b, after the first ONU (GPON ONU in the figure) is powered on, it scans the downstream sub-channels it can support through the default downstream bit carrying table, if it can reach on one of the downstream sub-channels Synchronize and correctly parse the downlink frame, it means that the MAC protocol supported by the shown downlink subchannel is consistent with the MAC protocol supported by the ONU, and the ONU can use the downlink subchannel as a temporary downlink subchannel and continue the registration process, The temporary downlink sub-channel can only be used for registration and cannot transmit service data. As shown in Figure 9b, the GPON ONU chooses to receive and synchronize downlink frames on sub-channel 0.

Optionally, in step 900, the OLT sends a physical layer parameter description message required for the normal operation of the first ONU to the first ONU, and after receiving the physical layer parameter description message, the first ONU configures according to the parameter description message, Then receive the first ONU registration request message, respond to the first ONU registration request message, and report the serial number SN.

Wherein, the physical layer parameters include the center frequency and number of subcarriers of the downlink subchannel, uplink transmit power, default modulation format, preamble length and mode, and so on.

Optionally, the first ONU can also report the ONU type to the OLT, and the reported ONU type can be reported together by reporting the serial number SN message; a new message format can also be customized and reported separately.

The ONU type can be the hardware parameter information of the ONU, the type code of the ONU or other parameters of the ONU device, and the OLT can learn information such as the frequency supported by the ONU, the uplink and downlink rates, the supported MAC protocol, and the bandwidth according to the ONU type .

Optionally, if the first ONU does not report the ONU type to the OLT, the OLT can obtain information such as frequencies supported by the first ONU, uplink and downlink transmission rates, supported MAC protocols, and bandwidth according to the serial number SN.

Step 903: The OLT receives the registration request response message from the ONU, judges whether the ONU is legal, and if it is legal, assigns an ONU identifier (also called an ONU-ID) to the ONU, and performs distance measurement on the ONU, Allocating a formal downlink sub-channel to the ONU, and establishing an association between the ONU identifier and the downlink sub-channel. The official downlink sub-channel can not only be used for registration, but also can transmit service data.

Optionally, the OLT records the mapping relationship information between the subchannel ID, ONU-ID and the MAC protocol, and the updated table 1 is (if the ONU of EPON, 10G-EPON, and 10G-GPON has not been assigned an ONU-ID, then In the ONU ID column, it is empty, and Table 1 shows the status after all ONU-IDs are allocated):

Table 1 Mapping relationship table between downlink sub-channel and MAC protocol

Subchannel ID MAC protocol ONU identification 0 GPON ONU-ID=1 1 EPON ONU-ID=2 2 10G-GPON ONU-ID=3 3 10G-EPON ONU-ID=4

The OLT sends the physical layer parameter description message required for the normal operation of the second ONU to the second ONU through the physical layer operation management message (Physical Layer Operation And Management, PLOAM) or other self-defined broadcast messages. After the second ONU is powered on After receiving the physical layer parameter description message, perform initialization configuration according to the parameter description message, then receive the second ONU registration request message, respond to the second ONU registration request message, and report the serial number SN.

Optionally, the second ONU can also report the ONU type to the OLT. The reported ONU type can be reported together by reporting the serial number SN message; a new message format can also be customized and reported separately. The ONU type can be the hardware parameter information of the ONU, the type code of the ONU or other parameters of the ONU device, and the OLT can learn information such as the frequency supported by the ONU, the uplink and downlink rates, the supported MAC protocol, and the bandwidth according to the ONU type .

Optionally, if the second ONU does not report the ONU type to the OLT, the OLT can obtain information such as frequencies, uplink and downlink transmission rates, supported MAC protocols, and bandwidths supported by the second ONU according to the serial number SN.

Specifically, after receiving the response message of the first ONU registration request message from the first ONU, the OLT verifies whether the serial number SN reported by the first ONU is legal, and if it is legal, the OLT allocates the first ONU for the first ONU -ID, and issue the first ONU-ID to the first ONU; if it is illegal, the OLT will kick the first ONU offline.

Referring to Table 1, for example, the OLT receives the SN reported from the ONU supporting the GPON protocol through the sub-channel with the ID of 0, and after verifying that the SN is legal, assigns the ONU-ID with the ONU-ID of 1 to the ONU that supports the GPON protocol , otherwise, if the SN is verified to be illegal, the ONU will be kicked offline.

Among them, whether it is a legal ONU can be based on the prior art, and the reported SN can be matched with the SN pre-stored by the OLT, or pre-configured, or input through the command line, or input through the network management system. If the match is consistent, the The ONU is a legal ONU; otherwise, it is an illegal ONU.

After the OLT successfully verifies the SN reported by the ONU, the OLT initiates the first ranging, and completes the ranging with the cooperation of the ONU.

The OLT allocates a formal downlink subchannel to the ONU, and sends the ID of the downlink subchannel to the ONU.

Among them, if the temporary sub-channel currently selected by the ONU meets one of the following conditions, the OLT assigns another downlink sub-channel to the ONU as the official sub-channel; otherwise, the OLT assigns the temporary sub-channel as the official downlink sub-channel to the ONU, the condition is :

The spectrum range supported by the ONU type does not match the current temporary subchannel; or, the ONU type does not match the MAC protocol carried by the current temporary subchannel; or, the bandwidth capacity of the current subchannel does not meet the bandwidth requirements of the ONU.

Among them, the OLT assigns another downlink sub-channel to the ONU as the official sub-channel, including:

The OLT allocates the first OFDM sub-channel that meets the needs of the ONU to the ONU; or, the OLT allocates any one of the multiple OFDM sub-channels that meet the needs of the ONU to the ONU; or, the OLT allocates the optimal OFDM that meets the needs of the ONU The sub-channel is allocated to the ONU; or the OLT is bound with multiple downlink OFDM sub-channels and allocated to the ONU.

As shown in FIG. 9b, the current temporary sub-channel meets the requirements of the GPON ONU, and the OLT allocates the sub-channel whose sub-channel ID is 0 to the ONU. As shown in Figure 9c, the current temporary sub-channel does not meet the requirements of the GPON ONU, and the OLT allocates the sub-channel whose sub-channel ID is 3 to the ONU. As shown in Figure 9d, the ONU of XG-PON has a large demand for the bandwidth of the sub-channel, and the ONU is synchronized on sub-channel 1 and 2. When the two temporary sub-channels meet the requirements of the XG-PON ONU, the OLT will sub-channel ID After subchannels 1 and 2 are bound, they are assigned to the XG-PON ONU as formal downlink subchannels.

Step 904: When the downlink sub-channel of the ONU changes, the OLT initiates a second ranging.

Specifically, in step 904, the OLT re-assigns the downlink subchannel for the ONU. The formal downlink subchannel of this allocation may be different from the previous temporary subchannel ID. Therefore, when the ONU downlink subchannel changes, the OLT needs to test again or obtain the ranging result of the ONU on the new downlink sub-channel through calculation, such as calculating the ONU’s ranging result by the difference between the same ONU’s ranging results on the allocated downlink sub-channel and the current sub-channel distance results; on the contrary, OLT does not need the second distance measurement.

Step 905: When the downlink sub-channel of the ONU changes, the OLT and the ONU need to determine the PMD layer working parameters of the sub-channel.

Generally, in OFDM-PON, OLT and ONU use the default bit bearing table B table (also called bit mapping table) to communicate during the registration process, and then determine the working parameters of the PMD layer. The OFDM signal has multiple subcarriers in the frequency domain. Each subcarrier can carry a different number of bits per clock according to the characteristics of the Signal Noise Ratio (SNR), that is, the B value. The B table is the subcarrier in the channel Mapping relationship table between ID and B value.

Optionally, the OLT and the ONU determine the method of the downlink B table: the OLT sends the downlink training sequence to the ONU, and the ONU calculates the signal-to-noise ratio (Signal Noise Ratio, SNR) of each subcarrier according to the received downlink training sequence, and then according to the SNR, calculate the downlink B table of the ONU. The ONU reports the calculated downlink B-list to the OLT, and the OLT performs configuration according to the downlink B-list.

Optionally, the OLT and the ONU determine the uplink B-table method: the ONU sends the uplink training sequence to the OLT, and the OLT calculates the signal-to-noise ratio (Signal Noise Ratio, SNR) of each subcarrier according to the received uplink training sequence, and then according to the SNR, calculate the upstream B table of the OLT. The OLT sends the calculated uplink B table to the ONU, and the ONU performs configuration according to the uplink B value.

After a period of time delay, the OLT and the ONU update the upstream and downstream B tables synchronously. The period of time delay may be pre-configured or set, or set in real time.

Step 906: The OLT and the ONU need to re-range after updating the uplink and downlink B tables, that is, the third time of ranging.

The third ranging process is the same as the first and second ranging processes, and will not be repeated here.

OLT and ONU enter the normal communication state.

Embodiment six

The embodiment of the present invention discloses an optical line terminal OLT. As shown in FIG. 10, the OLT includes:

The memory 100 is configured to store the corresponding relationship between each of the downlink sub-channels and the MAC protocol, wherein the first sub-channel corresponds to the first MAC protocol;

The first MAC module 101 is used to send a registration request message with the first MAC protocol through the first OFDM sub-channel; receive a registration request response message from the first ONU, judge whether the first ONU is legal, and if legal, then the The first ONU distributes the ONU mark; Establishes the association between the ONU mark and the OFDM sub-channel, and performs ranging on the first ONU; Distributes a formal downlink sub-channel for the first ONU;

Optionally, the first MAC module 101 is further configured to send physical layer configuration parameters related to the first OFDM subchannel by using the first MAC protocol through the first OFDM subchannel.

Optionally, the first MAC module 101 is configured to assign a formal downlink subchannel to the first ONU, specifically including:

When the spectrum range supported by the ONU type does not match the current temporary subchannel (the current temporary subchannel is the first OFDM subchannel); or, the ONU type does not match the MAC protocol carried by the current temporary subchannel; or, the current temporary subchannel When the bandwidth capacity of the channel fails to meet the bandwidth requirements of the ONU, the third OFDM sub-channel is allocated to the first ONU; at this time, the third OFDM sub-channel meets the following conditions:

The spectrum range supported by the first ONU matches the spectrum range of the third OFDM sub-channel; the PON type supported by the first ONU is consistent with the PON type of the first PON MAC module associated with the third OFDM sub-channel; and the third OFDM sub-channel The bandwidth capacity of meets the bandwidth requirement of the first ONU.

When there are multiple OFDM sub-channels that can meet the above conditions, the principle for OLT to allocate sub-channels can be:

The OLT allocates the first OFDM sub-channel that meets the needs of the ONU to the ONU; or, the OLT allocates any one of the multiple OFDM sub-channels that meet the needs of the ONU to the ONU; or, the OLT allocates the optimal OFDM that meets the needs of the ONU The sub-channel is allocated to the ONU; or the OLT is bound with multiple downlink OFDM sub-channels and allocated to the ONU.

Optionally, the first MAC module 101 is also used for reassigning the OFDM sub-channel to the first ONU when the official downlink sub-channel allocated by the OLT to the first ONU is different from the current temporary sub-channel. Take the second distance measurement.

Optionally, the first MAC module 101 is also used to update the upstream bit of the OLT after the OLT allocates a formal OFDM sub-channel (that is, the above-mentioned third OFDM sub-channel) to the first ONU. The bearer list is sent to the ONU.

Optionally, the first MAC module 101 is further configured to perform a third ranging on the first ONU after updating the bit bearing table.

The second MAC module 102 is used to send the registration request message with the second MAC protocol through the second OFDM sub-channel; receive the registration request response message from the second ONU, judge whether the second ONU is legal, if legal, then the The second ONU distributes the ONU identification; the second ONU performs ranging; distributes the downlink sub-channel for the second ONU;

Optionally, the second MAC module 102 is further configured to send physical layer configuration parameters related to the second OFDM subchannel by using the second MAC protocol through the second OFDM subchannel.

The second MAC module 102 is configured to allocate a downlink sub-channel for the second ONU, specifically including:

When the OLT satisfies at least one of the following conditions, allocate the second OFDM subchannel to the second ONU:

The spectrum range supported by the second ONU matches the spectrum range of the second OFDM sub-channel; the PON type supported by the second ONU is consistent with the PON type of the second PON MAC module associated with the second OFDM sub-channel; and the second OFDM sub-channel The bandwidth capacity of meets the bandwidth requirement of the second ONU.

Optionally, the second MAC module 102 is also used to perform the second ONU redistribution of the OFDM sub-channel for the second ONU when the official downlink sub-channel allocated by the OLT to the second ONU is different from the temporary sub-channel. secondary ranging.

Optionally, the second MAC module 102 is further configured to, after the OLT allocates a formal OFDM sub-channel to the second ONU, the OLT sends an updated uplink bit carrying table to the ONU.

Optionally, the second MAC module 102 is further configured to perform a third ranging on the second ONU after updating the bit bearing table.

MAC adaptation module 103, one end is coupled in PMD module, and one end is coupled with the first MAC module 101 and the second MAC module 102, is used for associating the first OFDM sub-channel to the first PON MAC module, and the second OFDM sub-channel is associated to The second PONMAC module: receives the upstream optical signal of the ONU, and sends the data signal demodulated by the PMD module to the first MAC module 101 or the second MAC module 102 according to the BWmap.

The PMD module 104 is used for the downlink direction, receives the data of the first PON MAC module through the first OFDM sub-channel, and modulates it into an OFDM signal; receives the data of the second PON MAC module through the second OFDM sub-channel, and modulates it into an OFDM signal ; In the uplink direction, receive the digital baseband OFDM signal sent by the analog-to-digital converter, and demodulate the data signal that the MAC can process;

Wherein, the OFDM subcarrier contained in the first OFDM subchannel is different from the OFDM subcarrier contained in the first OFDM subchannel; the first MAC protocol is a MAC protocol associated with the first OFDM subchannel, and the second MAC the protocol is a MAC protocol associated with the second OFDM subchannel, and the first MAC protocol is different from the second MAC protocol;

For the specific interaction process, refer to the description of Embodiment 5, which will not be repeated here.

The first MAC module 101 or the second MAC module 102 may use a Field-Programmable Gate Array (Field-Programmable Gate Array, FPGA), may use an Application Specific Integrated Circuit (ASIC), or may use a system chip ( System on Chip, SoC), can also use a central processing unit (Central Processor Unit, CPU), can also use a network processor (Network Processor, NP), can also use a digital signal processing circuit (Digital Signal Processor, DSP), or A microcontroller (Micro Controller Unit, MCU) may be used, and a programmable controller (Programmable Logic Device, PLD) or other integrated chips may also be used.

Embodiment seven

The embodiment of the present invention discloses an optical line terminal OLT, as shown in FIG. 11 , including a processor 1101 , a memory 1102 , a communication bus 1103 and a communication interface 1104 . The CPU 1101 , the memory 1102 and the communication interface 1104 are connected through a communication bus 1103 to complete mutual communication.

The processor 1101 may be a single-core or multi-core central processing unit, or a specific integrated circuit, or one or more integrated circuits configured to implement embodiments of the present invention.

The memory 1102 may be a high-speed RAM memory, or a non-volatile memory (non-volatile memory), such as a flash memory, or at least one disk memory.

The memory 1102 is used for the computer to execute the instructions 1105 . Specifically, the computer execution instructions 1105 may include program codes.

When the computer is running, the processor 1101 executes the computer to execute instructions 1105, and can execute the method flow described in the fifth embodiment.

Through the above technical solutions, when the PON system needs to be upgraded, there is no need to replace the OLT equipment, which can be upgraded smoothly and the upgrade cost can be saved. At the same time, the bandwidth can be increased on demand, and the utilization rate of the ODN is high, saving resources.

In the embodiment of the present invention, only G/E-PON and 10G-PON are taken as examples for illustration, but it is not limited to this. With the evolution of the network, single-channel 40G-PON and 100G-PON may appear in the network, and both The technical scheme of the present invention can be adopted to realize the coexistence of ONUs with multiple protocols and multiple rates, which will not be repeated here.

Those of ordinary skill in the art will understand that various aspects of the present invention, or possible implementations of various aspects, may be embodied as systems, methods or computer program products. Accordingly, aspects of the present invention, or possible implementations of various aspects, may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, etc.), or an embodiment combining software and hardware aspects, described in These are collectively referred to herein as "circuits," "modules," or "systems." In addition, aspects of the present invention, or possible implementations of various aspects, may take the form of computer program products, and computer program products refer to computer-readable program codes stored in computer-readable media.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. Computer-readable storage media include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or devices, or any suitable combination of the foregoing, such as random access memory (RAM), read-only memory (ROM), Erase Programmable Read-Only Memory (EPROM or Flash), Fiber Optic, Portable Read-Only Memory (CD-ROM).

The processor in the computer reads the computer-readable program code stored in the computer-readable medium, so that the processor can execute the functional actions specified in each step in the flow chart, or a combination of steps; A device that performs functional actions specified in each block or a combination of blocks.

The computer readable program code may 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 a remote computer, or entirely on the remote computer or server . It should also be noted that, in some alternative implementations, the functions noted at the steps in the flowcharts or blocks in the block diagrams may occur out of the order noted in the figures. For example, two steps, or two blocks shown in succession, may in fact be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.

Those skilled in the art can appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present invention.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

The above descriptions are only a few embodiments of the present invention, and those skilled in the art can make various changes or modifications to the present invention according to the disclosure of the application documents without departing from the spirit and scope of the present invention.

Claims (30)

1. a kind of device applied to passive optical network PON, the PON includes optical line terminal OLT and multiple optical network units ONU, which is characterized in that data, the dress are carried based on orthogonal frequency division multiplex OFDM between the OLT and the multiple ONU Set including：

Multiple PON media access control MACs modules, for coupling the physical layer block based on OFDM；

The multiple PON media access control MACs module includes the first PON MAC modules and the 2nd PON MAC modules, and described the The PON types that one PON MAC modules and the 2nd PON MAC modules are supported are different, and the PON types include MAC protocol and PON chains At least one of road rate；

The first PON MAC modules are associated with the first OFDM subchannels that the physical layer block based on OFDM is supported；

The 2nd PON MAC modules are associated with the 2nd OFDM subchannels that the physical layer block based on OFDM is supported, Wherein, the OFDM subcarriers that the OFDM subcarriers and the first OFDM subchannels that the 2nd OFDM subchannels include include are not Together.

2. device as described in claim 1, which is characterized in that further include parameter interface module, in OLT and the multiple OFDM sub-channel informations are transmitted between the first ONU in ONU.

3. device as claimed in claim 2, which is characterized in that the OFDM sub-channel information packets that the parameter interface module is transmitted The channel information that the OLT distributes to the first OFDM subchannels of the first ONU is included, the PON types and institute that the first ONU is supported The PON types for stating the associated first PON MAC modules of the first OFDM subchannels are consistent.

4. device as claimed in claim 3, which is characterized in that the OLT is at least one when meeting in the following conditions, distribution First OFDM subchannels give the first ONU：

The OFDM subchannels that first ONU is supported are matched with the subchannel that the first OFDM subchannels include；What the first ONU was supported Spectral range is matched with the spectral range of the first OFDM subchannels；The PON types that first ONU is supported are closed with the first OFDM subchannels The PON types of first PON MAC modules of connection are consistent；And the first OFDM subchannels bandwidth capacity meet the first ONU band Wide demand.

5. the device as described in claim 2-4 any one, which is characterized in that the parameter interface module is used for by described Physical layer negotiation process transmits the channel information for multiple OFDM subchannels that the physical layer block based on OFDM is supported.

6. the device as described in claim 2-4 any one, which is characterized in that the OFDM sub-channel informations include OFDM logical At least one of road mark and OFDM subcarrier informations.

7. device according to any one of claims 1-4, which is characterized in that further include management module, for establish ONU and The incidence relation of OFDM subchannels includes the incidence relation of the first ONU and the first OFDM subchannels.

8. device as claimed in claim 7, which is characterized in that the incidence relation indicates ONU marks and OFDM subchannels The relationship of channel information.

9. device according to any one of claims 1-4, which is characterized in that the first OFDM subchannels and described second OFDM subchannels are downlink subchannel.

10. device according to any one of claims 1-4, which is characterized in that the multiple PON media access control MACs mould Block is a part of component of the OLT.

11. a kind of optical line terminal OLT is applied to PON network, the PON includes the OLT and multiple optical network unit ONUs； It is characterized in that, carrying data based on orthogonal frequency division multiplex OFDM between the OLT and the multiple ONU, the OLT includes Multiple PON MAC modules and the physical layer block based on OFDM,

Wherein, the multiple PON MAC modules are the device as described in claim 1-10；

The physical layer block based on OFDM is used to transmit the data of the first PON MAC modules by the first OFDM subchannels； The data of the 2nd PON MAC modules are transmitted by the 2nd OFDM subchannels.

12. OLT as claimed in claim 11, which is characterized in that the physical layer block, for passing through the first OFDM subchannels The data for transmitting the first PON MAC modules transmit the data of the 2nd PON MAC modules by the 2nd OFDM subchannels, including：

Physical medium relating module PMD modules, the data for receiving the first PON MAC modules by the first OFDM subchannels, And it is modulated to ofdm signal；The data of the 2nd PON MAC modules are received by the 2nd OFDM subchannels, and are modulated to OFDM letters Number；

Digital analog converter, for the ofdm signal to be converted to analog electrical signal；

Optical sender：For the analog electrical signal to be converted to optical signal, by the optical signal launch to Optical Distribution Network ODN；

MAC adaptation modules close the 2nd OFDM subchannels for the first OFDM subchannels to be associated with the first PON MAC modules It is linked to the 2nd PON MAC modules.

13. a kind of passive optical network PON system, including optical line terminal OLT and multiple optical network unit ONUs；It is characterized in that, Data are carried based on orthogonal frequency division multiplex OFDM between the OLT and the multiple ONU；The OLT is such as claim 11- OLT described in 12.

14. a kind of communication means applied to PON, the PON includes optical line terminal OLT and multiple optical network unit ONUs, It is characterized in that, data is carried based on orthogonal frequency division multiplex OFDM between the OLT and the multiple ONU, the method includes：

The OLT is sent to the first ONU of the first PON types of support by the first OFDM downlinks subchannel and is assisted based on the first MAC The data information of view, twoth ONU transmissions of the OLT by the 2nd OFDM downlinks subchannel to the 2nd PON types of support are based on The data information of second MAC protocol, wherein OFDM subcarriers and the 2nd OFDM that the first OFDM subchannels include The subcarrier that channel is included is different.

15. method as claimed in claim 14, further includes：

The OLT sends the first downlink OFDM sub-channel informations that the OLT distributes to the first ONU to the first ONU.

16. method as claimed in claim 15, which is characterized in that the OLT is at least one when meeting in the following conditions, point The first ONU is given with the first OFDM subchannels：

The OFDM subchannels that first ONU is supported are matched with the subchannel that the first OFDM subchannels include；What the first ONU was supported Spectral range is matched with the spectral range of the first OFDM subchannels；The PON types that first ONU is supported are closed with the first OFDM subchannels The PON types of first PON MAC modules of connection are consistent；And the first OFDM subchannels bandwidth capacity meet the first ONU band Wide demand.

17. the method as described in claim 14-16 any one, further includes：The OLT sends OLT points described to the first ONU The first upgoing O FDM sub-channel informations of the first ONU of dispensing.

18. the method as described in claim 15-16 any one, which is characterized in that the OFDM sub-channel informations include At least one of OFDM gap markers and OFDM subcarrier informations.

19. a kind of register method of ONU is applied in PON network, the PON includes optical line terminal OLT and multiple optical-fiber networks Unit ONU；It is characterized in that, carrying data, institute based on orthogonal frequency division multiplex OFDM between the OLT and the multiple ONU The method of stating includes：

The OLT sends login request message by the first downlink OFDM subchannels with the first MAC protocol；

The OLT sends login request message by the second downlink OFDM subchannels with the second MAC protocol, wherein the first downlink The OFDM subcarriers that the OFDM subcarriers that OFDM subchannels include include with the second downlink OFDM subchannels are different；

The OLT receives the registration request response message from ONU, to be judged as that legal ONU distributes ONU marks and OFDM The ONU marks of distribution and being associated with for OFDM subchannels are established in channel.

20. method as claimed in claim 19, which is characterized in that further include：

OLT is sent on the first OFDM subchannels with the first MAC protocol to join with the relevant physical layer configurations of the first OFDM subchannels Number；

OLT is sent on the 2nd OFDM subchannels with the second MAC protocol to join with the relevant physical layer configurations of the 2nd OFDM subchannels Number, wherein the physical layer configuration parameter includes at least one of OFDM gap markers and OFDM subcarrier informations.

21. method as claimed in claim 19, which is characterized in that OFDM subchannels are distributed for the ONU, including：

When the spectral range and the first OFDM subchannels that ONU types are supported mismatch；Alternatively, ONU types and the first OFDM The MAC protocol of subchannel carrying mismatches；Alternatively, the bandwidth capacity of the first OFDM subchannels fails to meet the first ONU's When bandwidth demand, the 3rd OFDM subchannels of distribution give the first ONU, wherein the 3rd OFDM subchannels meet one of the following conditions：

The spectral range that first ONU is supported is matched with the spectral range of the 3rd OFDM subchannels；The PON classes that first ONU is supported Type is consistent with the associated PON types of first PON MAC modules of the 3rd OFDM subchannels；And the 3rd OFDM subchannels bandwidth Capacity meets the bandwidth demand of the first ONU.

22. according to the method for claim 21, which is characterized in that the method further includes：

When the 3rd OFDM subchannels are different from the first OFDM subchannels, the OLT carries out second to the ONU and surveys Away from.

23. according to the method for claim 22, which is characterized in that the method further includes：

When OLT is that the ONU distributes the 3rd OFDM subchannels, the bit carrying table of acquiescence is issued the ONU by OLT.

24. according to the method for claim 22, which is characterized in that further include：

The OLT issues downlink training sequence to the ONU by the 3rd OFDM downlink subchannels；

The OLT receives the downstream bits value of the ONU by the 3rd OFDM downlink subchannels, generates newer bit and holds Newer bit carrying table is simultaneously issued the ONU by load table；

The OLT carries out third time ranging to the ONU.

25. a kind of optical line terminal OLT, which is characterized in that including：

Memory, the mapping relation information for preserving each downlink subchannel and MAC protocol；

First media access control MAC module is disappeared for passing through the first OFDM subchannels with the first MAC protocol transmission registration request Breath；The registration request response message from the first ONU is received, judges whether the first ONU is legal, is described first if legal ONU distributes ONU marks；Ranging is carried out to the first ONU, OFDM subchannels are distributed for the first ONU；

Second MAC module, for sending login request message by the 2nd OFDM subchannels with the second MAC protocol；Reception comes from The registration request response message of 2nd ONU judges whether the 2nd ONU is legal, and ONU is distributed for the 2nd ONU if legal Mark；Ranging is carried out to the 2nd ONU, OFDM subchannels are distributed to the 2nd ONU；

Wherein, the OFDM subcarriers that the OFDM subcarriers and the 2nd OFDM subchannels that the first OFDM subchannels include include are not Together；First MAC protocol is to be and the 2nd OFDM with the first associated MAC protocol of OFDM subchannels, second MAC protocol The associated MAC protocol of subchannel, and first MAC protocol is different from second MAC protocol；

Physical medium is associated with PMD modules, is used for down direction, and the first PON MAC modules are received by the first OFDM subchannels Data, and it is modulated to ofdm signal；The data of the 2nd PON MAC modules are received by the 2nd OFDM subchannels, and are modulated to Ofdm signal；

MAC adaptation modules, one end are coupling in the PMD modules, and one end is coupled with first MAC module and the second MAC module, For the first OFDM subchannels to be associated with the first PON MAC modules, the 2nd OFDM subchannels are associated with the 2nd PON MAC moulds Block；When receiving ONU uplink optical signals, according to bandwidth allocation bitmap BWmap, the ofdm signal that the PMD modules are demodulated It is sent to the first MAC module or the second MAC module.

26. OLT according to claim 25, which is characterized in that first MAC module is additionally operable to through the first OFDM Subchannel is sent and the first relevant physical layer configuration parameter of OFDM subchannels with the first MAC protocol.

27. OLT according to claim 25, which is characterized in that first MAC module, for under the first ONU distribution Row subchannel, specifically includes：

When the spectral range that ONU types are supported and the first OFDM subchannels mismatch；Alternatively, ONU types and described first The MAC protocol of OFDM subchannels carrying mismatches；Alternatively, the bandwidth capacity of the first OFDM subchannels fails satisfaction first When the bandwidth demand of ONU, distribution the 3rd OFDM subchannels give the first ONU, wherein the 3rd OFDM subchannels meet the following conditions it One：

The spectral range that first ONU is supported is matched with the spectral range of the 3rd OFDM subchannels；The PON classes that first ONU is supported Type is consistent with the associated PON types of first PON MAC modules of the 3rd OFDM subchannels；And the 3rd OFDM subchannels bandwidth Capacity meets the bandwidth demand of the first ONU.

28. OLT according to claim 27, which is characterized in that first MAC module is additionally operable to when the 3rd OFDM When channel is different from the first OFDM subchannels, second of ranging is carried out to the first ONU.

29. the OLT according to claim 27 or 28, which is characterized in that the first MAC module is additionally operable to as OLT be described the After one ONU is assigned with the 3rd OFDM subchannels, newer upstream bits carrying table is sent to the ONU by the OLT.

30. OLT according to claim 29, which is characterized in that first MAC module is additionally operable to when OLT will be newer After bit carrying table is sent to the ONU, third time ranging is carried out to the first ONU.