CN102149027A

CN102149027A - Passage switching method and system and downlink data transmitting method

Info

Publication number: CN102149027A
Application number: CN2010101125275A
Authority: CN
Inventors: 张伟良; 张德智; 耿丹
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2010-02-05
Filing date: 2010-02-05
Publication date: 2011-08-10
Anticipated expiration: 2030-02-05
Also published as: WO2011094990A1; CN102149027B

Abstract

The invention provides a passage switching method, a passage switching system and a downlink data transmitting method. The passage switching method comprises the following steps that: an optical line terminal (OLT) which works currently transmits downlink data in which the identity information of the OLT is carried to an optical network unit (ONU); the ONU receives and analyzes the downlink data to acquire the identity information of the OLT which works currently; and the ONU switches a passage when detecting that the identity information of the OLT which works currently changes. Certain conventional registering and activating steps are skipped by the ONU, so that the time required by switching the OLT and the ONU from a principal passage to a backup passage is reduced, and the communication efficiency between the OLT and the ONU is improved.

Description

Path switching method, system and downlink data transmission method

Technical field

The present invention relates to passive optical network technique, relate in particular to path switching method, system and downlink data transmission method in a kind of EPON.

Background technology

Gigabit passive optical network (GPON, Gigabit-Capable Passive Optical Network) technology is important techniques branch in EPON (PON) family, with other PON technology type seemingly, GPON also is a kind of passive light access technology that adopts some the multidrop topology structure.

Fig. 1 is the topological structure schematic diagram of existing GPON system, as shown in Figure 1, GPON is by the optical line terminal (OLT of office's side, Optical Line Terminal), the optical network unit (ONU of user side, OpticalNetwork Unit) and Optical Distribution Network (ODN, Optical Distribution Network) forms, adopt the network configuration of point usually to multiple spot.ODN is made up of Passive Optical Components such as monomode fiber, optical branching device, optical connectors, for the physical connection between OLT and the ONU provides light-transmitting medium.

In the GPON system, the transfer of data of down direction (by OLT to ONU) adopts broadcast mode, each ONU receives all frames respectively, obtains one's own frame according to ONU sign (ONU-ID), GEM port-mark (GEM-Port ID), configuration identifier (Allocation-ID) again.For the transfer of data of up direction (from ONU to OLT) because each ONU need share transmission medium, so each ONU should be in OLT arranges transmit ascending data to the time slot of oneself.

Fig. 2 is the Transmission Convergence (GTC of GPON, G-PON Transmission Convergence) schematic diagram of Ceng downlink frame structure, as shown in Figure 2, the downlink frame of GPON is by downlink physical controll block (PCBd, Physical Control Block downstream) and payload two parts form, wherein, PCBd is by physics synchronization field (Psync, Physical Synchronization), the Ident territory, the downlink physical layer operation, manage and safeguard (PLOAMd, Physical Layer Operation, Administraion and Maintenancedownstream) territory, bit interleaved parity territory (BIP, Bit Interleaved Parity), information payload length field (Plend, Payload Length downstream) and upstream bandwidth mapping territory (US BWmap) are formed.

In EPON was disposed, if the staff installs ONU in PON system as shown in Figure 1, under some scene, OLT and ONU distance may be far away, so that reach tens kilometers.The characteristic information that does not comprise OLT in the downlink frame according to OLT transmission (as shown in Figure 2) in the present GPON agreement, but when the staff installs ONU at the branch optical fiber access point, need obtain this and put pairing OLT port information, be installed in the correct PON system to guarantee ONU.Be installed among the affiliated ODN of correct OLT if can not guarantee ONU, may cause the ONU cisco unity malfunction of installing.

In addition, in the application deployment of EPON, have certain customers to need higher fail safe, wish that operator can provide a kind of security mechanism to guarantee that its service channel does not interrupt, perhaps the requirement of time one-level is, can have no progeny in service channel and recover fast.This has just proposed protection path and the requirement of switched path fast to the EPON of carrying customer service operation.

Fig. 3 is in the existing passive optical network standards, a kind of typical network architecture schematic diagram under the protected mode, and Fig. 4 is in the existing passive optical network standards, the another kind of typical network architecture schematic diagram under the protected mode.

Shown in Figure 3 is the mode of the protection trunk optical fiber of type B.As shown in Figure 3, two the light mouth PON LT (0) of OLT and PON LT (1) all are connected to the optical splitter of a 2:N, and this optical splitter down direction is connected to each ONU (label is from N altogether of #1 to #N) by optical fiber respectively.The light mouth PON LT (0) that supposes OLT is the main path of using by the path that optical splitter arrives ONU, and the light mouth PON LT (1) of OLT is a stand-by channel by the path that optical splitter arrives ONU.Have no progeny in main, will enable stand-by channel as communicating by letter between the service path maintenance optical network unit of optical network unit and optical line terminal and optical line terminal with the service path of path as optical network unit and optical line terminal.

Shown in Figure 4 is the all-fiber protection mode of Type C.As shown in Figure 4, the light mouth PON LT (0) of OLT is connected to the optical splitter 1 of 1:N, and 2, two optical splitters of optical splitter that the light mouth PON LT (1) of OLT is connected to 1:N are connected with each ONU by optical fiber respectively.The path that the light mouth PON LT (0) that supposes OLT arrives ONU by optical splitter 1 is the main path of use, and the light mouth PON LT (1) of OLT is a stand-by channel by the path of optical splitter 2 arrival ONU.Have no progeny in main, will enable stand-by channel as communicating by letter between the service path maintenance optical network unit of optical network unit and optical line terminal and optical line terminal with the service path of path as optical network unit and optical line terminal.

Under the existing protected mode of Fig. 3 and EPON shown in Figure 4, in conjunction with Fig. 5, with main be example with the process of enabling stand-by channel behind the path fault, the logic state transition process of optical network unit is described.

Fig. 5 for existing main when enabling stand-by channel behind the path fault, the schematic diagram of the logic state transition process of optical network unit, as shown in Figure 5, suppose that ONU and the OLT master by between the two is that PONLT (0) mouthful path is communicated by letter with path, ONU is in running status (O5); Main with having no progeny in the path, comprising:

ONU, produces lock-out (LOS/LOF) alarm, and enters ejection state (O6) with the light signal of path detection less than OLT the master, and ONU enters initial condition (O1) after being in the duration of time above the setting of TO2 timer of ejection state (O6);

OLT enables the path that stand-by channel is PON LT (1) mouthful, synchronized reserve path related protocol configuration parameter (as transmitting optical power, ONU ID, T-CONT ID, GEM ID etc.), and send that downlink optical signal and ONU carry out that frame is delimited and synchronously to ONU;

After ONU detects the downlink optical signal of OLT, eliminate the LOS/LOF alarm of OLT, by stand-by channel and OLT finish that frame is delimited and synchronous after, ONU changes holding state (O2) over to from initial condition (O1);

Change serial-number-state (O3) over to from holding state (O2) after the up expense parameter that ONU reception OLT sends; Up expense parameter comprises: the lead code bit type, delimiter parameter (Delimiter) is used to indicate the horizontal parameter of other ONU transmitting optical power of level of ONU transmitting optical power and other parameter.

After OLT switched to stand-by channel from the master with path, need were redistributed the ID of the ONU of its management, and the ID of each ONU after will redistributing is sent to each ONU; ONU changes distance measuring states (O4) over to from serial-number-state (O3) after receiving the ONU-ID information of OLT transmission;

ONU changes running status (O5) over to from distance measuring states (O4) after receiving balanced time delay (EqD, the Equalization Delay) message of OLT transmission;

So far, the stand-by channel between ONU and OLT is set up fully, and ONU and OLT carry out information interaction by stand-by channel.

In path handoff procedure shown in Figure 5, after setting up the physical layer path on the stand-by channel, OLT need send related datas such as EqD to all ONU, each ONU need upgrade self parameter after receiving related data, and and the OLT light mouth of stand-by channel between finish adjustment to transmitting power, could recover normal operating conditions at last.Network configuration with type B shown in Figure 3 is an example, when an ONU that OLT managed has 32, in the path handoff procedure, OLT is need be with 32 ONU mutual and all finish as shown in Figure 5 state transition process (promptly experiencing O1, O2, O3, O4 and O5).As seen, there is following problem in existing path switching flow:

(1) each ONU all finishes above-mentioned a series of state transition, makes OLT need bear a large amount of message transmission work;

(2) in processing procedure, because the finite capacity of path between OLT and the ONU, in the GTC downlink frame, there are not enough capacity to deposit Physical Layer OAM (PLOAM, Physical LayerOperation Administration and Maintenance) message supports 32 ONU to finish aforesaid state transition process simultaneously, therefore, most of ONU need wait for the arrival of news, prolonged the time that path switches, influenced the fast quick-recovery proper communication of ONU and OLT, it is consuming time substantially at 100 milliseconds more than the magnitude to make ONU and OLT recover operate as normal, can not satisfy the requirement of user to the fast quick-recovery of network failure.

Summary of the invention

In view of this, main purpose of the present invention is to provide path switching method and the system in a kind of EPON, can shorten the time that path switches, and realizes the recovery of ONU and OLT proper communication fast.

Another object of the present invention is to provide the downlink data transmission method in a kind of EPON, can guarantee that ONU is installed among the affiliated ODN of correct OLT, guarantees the operate as normal of ONU.

For achieving the above object, technical scheme of the present invention is achieved in that

A kind of path switching method comprises:

The work at present optical line terminal OLT sends the downlink data of the identity information that carries this OLT to optical network unit ONU;

ONU receives and resolves described downlink data, obtains the identity information of work at present OLT; When the identity information that detects work at present OLT as ONU changed, the ONU execution path switched.

When the described identity information that detects work at present OLT as ONU changed, the ONU execution path switched and comprises:

When the identity information that ONU detects work at present OLT changes, self running parameter is configured at the corresponding relation of the running parameter on the stand-by channel according to the identity information of the OLT on the stand-by channel of self storage and ONU enter operating state behind the running parameter of stand-by channel.

Described work at present OLT comprises to the downlink data that ONU sends the identity information that carries this OLT:

When the master uses path as active channel, the main downlink data that sends the identity information that carries this OLT with the OLT on the path to ONU; After the master was invalid with path, stand-by channel was as active channel, and the OLT on the stand-by channel sends the downlink data of the identity information that carries this OLT to ONU.

Described ONU receives the identity information from described OLT when being in following state: holding state; Perhaps, transfer to serial-number-state, and be in serial-number-state from holding state; Perhaps, transfer to serial-number-state, transfer to distance measuring states from serial-number-state then, and be in distance measuring states from holding state.

ONU stores the identity information of the OLT on the stand-by channel and the corresponding relation of the running parameter of ONU on stand-by channel in the following manner:

Main with path during as active channel, the OLT on the stand-by channel sends to self identity information main with the OLT on the path, and finishes measurement to the running parameter of all ONU on stand-by channel by main with the OLT on the path;

The master sends to corresponding ONU with the OLT on the path with the identity information of the OLT on the stand-by channel that receives and the running parameter of ONU on stand-by channel that measures;

Described ONU receives the identity information of the OLT on the main described stand-by channel that sends with the OLT on the path and ONU behind the running parameter on the stand-by channel, stores the corresponding relation of described identity information and described running parameter.

Identity information and the running parameter of ONU on stand-by channel of OLT on the ONU storage stand-by channel, and the corresponding relation of the two is the system default setting.

Described OLT sends the downlink data of the identity information that carries described OLT by following manner:

Described identity information is carried in the downlink frame in the newly-increased territory, and described newly-increased territory is arranged in the downlink physical controll block PCBd territory of the downlink frame of GPON, perhaps, is arranged in the GEM frame head of payload of the downlink frame of GPON;

Perhaps described identity information is carried in the existing territory in the downlink frame, described existing territory is down physical layer OAM PLOAMd territory, or payload field.

The identity information of described OLT comprises one of the following or combination in any: the emission luminous power information of the groove position identifying information of the city at the country at OLT place, OLT place, OLT identifying information, OLT, the port identification information of OLT work at present, OLT; Perhaps,

There is the logical message of presetting corresponding relation with the identity information of actual OLT.

A kind of path switched system comprises optical line terminal OLT and optical network unit ONU;

Described OLT comprises main with OLT on the path and the OLT on the stand-by channel, and main with path or stand-by channel during as active channel, the OLT on the active channel is used for sending to ONU the downlink data of the identity information that carries this OLT;

Described ONU is used for when the master uses the path proper communication, the identity information of the OLT on the storage stand-by channel and the corresponding relation of the running parameter of ONU on stand-by channel; Also be used for receiving and resolving described downlink data, obtain the identity information of work at present OLT; And be used for when the identity information that detects work at present OLT changes, according to the described corresponding relation of self storage self running parameter is configured to enter operating state behind the running parameter of stand-by channel.

When the master uses path as active channel,

OLT on the described stand-by channel is used for self identity information is sent to described master with the OLT on the path;

Described master is used to finish measurement to the running parameter of all ONU on stand-by channel with the OLT on the path, and the identity information of the OLT on the stand-by channel that receives and the running parameter of ONU on stand-by channel that measures are sent to corresponding ONU;

Described ONU is used to receive main with the identity information of the OLT on the described stand-by channel of the transmission of the OLT on the path and ONU stores described identity information and described running parameter behind the running parameter on the stand-by channel corresponding relation; Perhaps, identity information and the running parameter of ONU on stand-by channel of the OLT on the described ONU storage stand-by channel, and the corresponding relation of the two is the system default setting.

A kind of downlink data transmission method comprises:

ONU receives and resolves described downlink data, and the identity information of acquisition work at present OLT also shows.

Described ONU is the handheld terminal of band display screen.

Described ONU shows the identity information of described OLT by webmaster.

The technical scheme that provides from the invention described above as can be seen, realize the method and system that path switches by the present invention, OLT and ONU are after the master breaks down with path, transferred on the stand-by channel fast, ONU skips existing registration and activates step, reduced OLT and ONU and used the required time of conversion that is routed to stand-by channel, improved the communication efficiency between OLT and the ONU from the master.In the method that downlink data of the present invention sends, OLT sends the downlink data of the identity information that carries OLT to ONU, ONU receives downlink data and can resolve the identity information that identifies work at present OLT and show, thereby guaranteed that ONU is installed among the correct PON, has guaranteed the normal mounting of ONU.

Description of drawings

Fig. 1 is the topological structure schematic diagram of existing GPON system;

Fig. 2 is the schematic diagram of the downlink frame structure of the GTC layer of existing GPON;

Fig. 3 is in the existing passive optical network standards, a kind of typical network architecture schematic diagram under the protected mode;

Fig. 4 is in the existing passive optical network standards, the another kind of typical network architecture schematic diagram under the protected mode;

Fig. 5 for existing main when enabling stand-by channel behind the path fault, the schematic diagram of the logic state transition process of optical network unit;

Fig. 6 is the schematic diagram of the downlink frame structure of the GTC layer of GPON of the present invention;

Fig. 7 realizes the flow chart that path switches for the present invention.

Embodiment

Downlink data transmission method of the present invention comprises: OLT sends the downlink data of the identity information carry OLT to ONU, and ONU receives and also resolves downlink data, and the identity information that obtains work at present OLT also shows.Wherein, can carry the identity information of OLT in the following manner:

Mode one is carried at the identity information of OLT in newly-increased in the downlink frame territory, and this newly-increased territory can be arranged in the PCBd territory of GPON downlink frame, also can be arranged in the GEM frame head of the payload of GPON downlink frame.To increase the identity information that a territory is used to carry the OLT that sends this downlink frame in the PCBd territory of GPON downlink frame is example, and Fig. 6 is the schematic diagram of the downlink frame structure of the GTC layer of GPON of the present invention.

As shown in Figure 6, in the PCBd territory of the downlink frame of GPON, include PON identifying information (PON-ID, PON identifier) territory, the PON-ID territory is (Fig. 6 has just provided an example to the position of PON-ID, and PON-ID also can be positioned at other position in PCBd territory) between Psync territory and Ident territory.The PON-ID territory is used to carry the identity information (being PON-ID information) of OLT, comprises one of following or combination in any: the port identification information (Port-ID) of the groove position identifying information (Slot-ID) of the city (City) at the country at OLT place (Country), OLT place, OLT identifying information (OLT-ID), OLT, OLT work now, the emission luminous power information (Power) of OLT.Certainly, the identity information that the PON-ID territory is used to carry OLT also can be a logical message, promptly has the code name or the coding of default corresponding relation with actual information.

Like this, in the application deployment of GPON, when the staff need be installed to an ONU in the GPON system, the staff selects the access node of a GPON, and (for example with a device that can receive the GPON downlink frame, the handheld terminal of band display screen) is connected to this access node to receive downlink frame, the staff is according to the information in the PON-ID territory in the downlink frame that receives, whether the access node of judging current use belongs to the PON that ONU will insert, thereby has guaranteed that ONU is installed among the correct PON.Further, the OLT luminous power that ONU receives after the emission luminous power information of the OLT in the PON-ID territory and ONU self receives compares, and calculates the loss of PON system link.

Mode two is carried at the identity information of OLT in the existing territory in the downlink frame, in PLOAMd territory (or claiming PLOAM message), or in the payload.Wherein,

The PLOAM message of carrying the identity information of OLT is referred to herein as PON-ID message, and the form of PON-ID message is as shown in table 1.

Table 1

As shown in table 1, the 1st byte of PON-ID message is the value of ONU-ID, and the content of this byte is 11111111, and expression is broadcasted this message to all ONU; The content of this byte is 11111110, and expression is broadcasted this message to the ONU of all unregistered activation; When the content of this byte is value ONU-ID1 except that 11111111 and 11111110, represent that this message sends to the ONU of ONU-ID value for ONU-ID1.

The type of this PLOAM message of content representation of the 2nd byte of PON-ID message is a PON identifying information type.

The content of the 3rd to the 12nd byte of PON-ID message is the identity information of OLT, comprising: the emission luminous power information of the city at the country at OLT place, OLT place, OLT-ID, Slot-ID, Port-ID, OLT.

OLT can send the PON-ID message of broadcasting with certain cycle; Perhaps, OLT sends PON-ID message for the ONU that sends the PON-ID request after receiving the PON-ID request message that certain ONU sends.The form of the PON-ID request message that ONU sends is as shown in table 2.

Table 2

As shown in table 2, the 1st byte of PON-ID request message is the value of ONU-ID, represents that this message is from the ONU of ONU-ID value for ONU-ID1.

The type of this PLOAM message of content representation of the 2nd byte of PON-ID request message is the PON-ID request type.

Also can carry the identity information of OLT by newly-built OMCI message, the OMCI message of carrying the identity information of OLT is referred to herein as PON-ID message.OMCI message can comprise type of message (Message type) territory, and message content (Message contents) territory.Wherein, the type of message territory comprises and is used to represent that this message is the PON-ID message of carrying the identity information of OLT, such as bit 1～bit 5; The message content territory is used to carry the identity information of OLT, comprising: the emission luminous power information of the city at the country at OLT place, OLT place, OLT-ID, Slot-ID, Port-ID, OLT.The value that encapsulates the port-mark (Port-ID) in the GEM frame head of GEM frame of this OMCI can be set to 11111110, represents that the type of the OMCI message of this GEM frame encapsulation is a PON-ID message.

It is the OMCI message of PON-ID that OLT can send type of message with certain cycle, after ONU receives the OMCI message of the PON-ID type that OLT sends, obtains to send the identity information of the OLT of this message according to the message content territory of OMCI message.

After pass-through mode two, ONU receive the PON-ID message that OLT sends, according to after the emission luminous power information that receives the OLT in the PON-ID message and the OLT luminous power received of ONU self compare, calculate the loss of PON system link.

In type B in the prior art and the PON of the Type C protection structure, current path at work is called the main path of using, and after the master broke down with path, OLT (and ONU) switched on the stand-by channel.Fig. 7 as shown in Figure 7, may further comprise the steps for the present invention realizes the flow chart that path switches:

Step 700: main with path during as the active channel proper communication, the main downlink data that adopts aforesaid way one or mode two to send to carry self identity information with the OLT on the path is to ONU, and ONU receives and also resolves the identity that downlink data obtains work at present OLT; The identity information PON-ID of the OLT of ONU storage stand-by channel and ONU are at the corresponding relation of the running parameter of stand-by channel.

This step roughly comprises: when the master uses path as active channel, OLT on the stand-by channel sends to self identity information main with the OLT on the path, and the OLT on the stand-by channel finishes surveying work to the running parameter of all ONU on stand-by channel by main with the OLT on the path; Main identity information and the running parameter of ONU on stand-by channel of OLT on the stand-by channel sent to all ONU by newly-built PLOAM message or GEM frame with the OLT on the path; After described ONU receives main above-mentioned information with the transmission of the OLT on the path, the identity information of the OLT on the ONU storage stand-by channel and the corresponding relation of the running parameter of ONU on stand-by channel; Perhaps,

Identity information and the running parameter of ONU on stand-by channel of OLT on the described ONU storage stand-by channel, and the corresponding relation of the two is the system default setting.What this step was emphasized is no matter that by what method, ONU stores the identity information PON-ID of the OLT on the stand-by channel and the corresponding relation of the running parameter of ONU on stand-by channel.

The main running parameter of ONU storage in this step with path and stand-by channel, the OLT identity information that comprises two paths, be PON-ID information, lead code bit type, delimiter parameter (Delimiter), the horizontal parameter of ONU transmitting optical power, balanced time delay (EqD, Equalization Delay), and two OLT distribute to ONU ID of oneself etc.Wherein, PON-ID information comprises the city, OLT identifying information (OLT-ID), the groove position identifying information (Slot-ID) of OLT, the identifying information (Port-ID) of the present working port of OLT, the emission luminous power information of OLT at country, the OLT place at OLT place, ONU is according to the identity of the in running order OLT of PON-ID information Recognition of OLT transmission, and according to the above-mentioned running parameter of the PON-ID information configuration self of the OLT that receives, with set up and work OLT between communication.

Step 701: after the master was invalid with path, the OLT on ONU and the stand-by channel realized synchronously.

Carry out data communication between ONU and OLT main with path invalid after, ONU enters ejection state (O6) after producing lock-out (LOS/LOF) alarm, the time that ONU is in ejection state (O6) enters initial condition (O1) after surpassing default TO2 length of timer.OLT enables stand-by channel and sends downlink frame, and ONU finishes with OLT synchronous, and ONU enters into the O2 state.

Step 702: stand-by channel is as active channel, OLT on the stand-by channel adopts mode one or mode two to send to carry the downlink data of self identity information (PON-ID) to give ONU, ONU receives and also to resolve downlink data, and according to the identity of the PON-ID information acquisition work at present OLT in the downlink data.After ONU found that the identity information of described OLT changes, ONU was configured to self running parameter at the corresponding relation of stand-by channel running parameter according to the OLT identity information on the stand-by channel of self storage and ONU enter operating state behind the running parameter of stand-by channel.

Realize the method that path switches by the present invention, OLT and ONU are after the master breaks down with path, transferred on the stand-by channel fast, ONU skips existing registration from the O2 state to the O5 state and activates step, reduced OLT and ONU to greatest extent and used the required time of conversion that is routed to stand-by channel, farthest improved the communication efficiency between OLT and the ONU from the master.

The specific implementation of step 702 also can be: ONU according to existing method from the O2 state transitions to the O3 state; After the ONU of O3 state receives that OLT adopts the downlink frame or PON-ID message of mode one or mode two transmissions, according to the PON-ID content of carrying in downlink frame or the PON-ID message, obtain the identity information of work at present OLT, ONU is according to the corresponding relation of the running parameter of the PON-ID of stand-by channel of storage and stand-by channel, the running parameter that disposes self is the running parameter of stand-by channel, and ONU enters operating state.As seen, OLT and ONU are after the master breaks down with path, transferred on the stand-by channel fast, ONU skips existing registration from the O3 state to the O5 state and activates step, reduced OLT and ONU and used the required time of conversion that is routed to stand-by channel, improved the communication efficiency between OLT and the ONU from the master.

The specific implementation of step 702 can also be: ONU according to existing method from the O2 state transitions to the O3 state, then from the O3 state transitions to the O4 state; After the ONU of O4 state receives that OLT adopts the downlink frame or PON-ID message of mode one or mode two transmissions, according to the PON-ID content of carrying in downlink frame or the PON-ID message, obtain the identity information of work at present OLT, ONU is according to the corresponding relation of the running parameter of the PON-ID of stand-by channel of storage and stand-by channel, the running parameter that disposes self is the running parameter of stand-by channel, and ONU enters operating state.As seen, OLT and ONU are after the master breaks down with path, transferred on the stand-by channel fast, ONU skips existing registration from the O4 state to the O5 state and activates step, reduced OLT and ONU and used the required time of conversion that is routed to stand-by channel, improved the communication efficiency between OLT and the ONU from the master.

At the described path switching method of Fig. 7 of the present invention, a kind of path switched system also is provided, comprise OLT and ONU, wherein,

OLT comprises main with OLT on the path and the OLT on the stand-by channel, and main with path or stand-by channel during as active channel, the OLT of active channel is used for sending to ONU the downlink data of the identity information that carries this OLT;

ONU is used for when the master uses the path proper communication, the identity information of the OLT on the storage stand-by channel and the corresponding relation of the running parameter of ONU on stand-by channel; Also be used for receiving and resolving downlink data, obtain the identity information of work at present OLT; And be used for when the identity information that detects work at present OLT changes, according to the above-mentioned corresponding relation of self storage self running parameter is configured to enter operating state behind the running parameter of stand-by channel.

ONU receives the PON-ID content that OLT sends when being in O2 state or O3 state or O4 state, obtain the identity information of work at present OLT, ONU is according to the corresponding relation of the running parameter of the PON-ID of stand-by channel of storage and stand-by channel, the running parameter that disposes self is the running parameter of stand-by channel, and ONU enters operating state.

When the master used path as active channel, the OLT on the stand-by channel was used for sending to the identity information of self main with the OLT on the path; Main be used to finish measurement, and the identity information of the OLT on the stand-by channel that receives and the running parameter of ONU on stand-by channel that measures are sent to corresponding ONU the running parameter of all ONU on stand-by channel with the OLT on the path; ONU is used to receive main with the identity information of the OLT on the stand-by channel of the transmission of the OLT on the path and ONU stores this identity information and running parameter behind the running parameter on the stand-by channel corresponding relation;

Perhaps, identity information and the running parameter of ONU on stand-by channel of the OLT on the ONU storage stand-by channel, and the corresponding relation of the two is the system default setting.

Need to prove that the PON-ID content that sends that the present invention proposes can be subjected to the protection of forward error correction (FEC, Forward Error Correction) coding in downlink frame, also can be not in the scope of FEC coding.

The downlink data transmission method that comprises the PON-ID content that the present invention proposes is equally applicable to the PON of future generation system based on GPON.

The above is preferred embodiment of the present invention only, is not to be used to limit protection scope of the present invention, all any modifications of being done within the spirit and principles in the present invention, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.

Claims

1. a path switching method is characterized in that, comprising:

2. path switching method according to claim 1 is characterized in that, when the described identity information that detects work at present OLT as ONU changed, the ONU execution path switched and comprises:

3. path switching method according to claim 1 is characterized in that, described work at present OLT comprises to the downlink data that ONU sends the identity information that carries this OLT:

4. path switching method according to claim 1 is characterized in that described ONU receives the identity information from described OLT when being in following state: holding state; Perhaps, transfer to serial-number-state, and be in serial-number-state from holding state; Perhaps, transfer to serial-number-state, transfer to distance measuring states from serial-number-state then, and be in distance measuring states from holding state.

5. path switching method according to claim 2 is characterized in that, ONU stores the identity information of the OLT on the stand-by channel and the corresponding relation of the running parameter of ONU on stand-by channel in the following manner:

6. path switching method according to claim 2 is characterized in that, ONU stores the identity information of the OLT on the stand-by channel and the corresponding relation of the running parameter of ONU on stand-by channel in the following manner:

7. according to each described path switching method of claim 1 to 6, it is characterized in that described OLT sends the downlink data of the identity information that carries described OLT by following manner:

8. according to each described path switching method of claim 1 to 6, it is characterized in that the identity information of described OLT comprises one of the following or combination in any: the emission luminous power information of the groove position identifying information of the city at the country at OLT place, OLT place, OLT identifying information, OLT, the port identification information of OLT work at present, OLT; Perhaps,

9. a path switched system is characterized in that, comprises optical line terminal OLT and optical network unit ONU;

10. path switched system according to claim 9 is characterized in that, when the master uses path as active channel,

11. a downlink data transmission method is characterized in that, comprising:

12. downlink data transmission method according to claim 11 is characterized in that, described OLT sends the downlink data of the identity information that carries described OLT by following manner:

13. downlink data transmission method according to claim 11, it is characterized in that the identity information of described OLT comprises one of the following or combination in any: the emission luminous power information of the groove position identifying information of the city at the country at OLT place, OLT place, OLT identifying information, OLT, the port identification information of OLT work at present, OLT; Perhaps,

14. downlink data transmission method according to claim 11 is characterized in that, described ONU is the handheld terminal of band display screen.

15. downlink data transmission method according to claim 11 is characterized in that, described ONU shows the identity information of described OLT by webmaster.