Summary of the invention
The technical problem that the present invention will solve is in order to overcome the defective that PON of the prior art system only supports the distance of 20KM and lacks the circuit debugging technique, a kind of light bridge equipment and distance-finding method thereof based on GPON to be provided.
The present invention solves above-mentioned technical problem through following technical proposals:
A kind of light bridge equipment based on GPON, its characteristics are that it comprises:
PON downlink transfer layer analysis module is used for reusing the descender of GPON MAC;
Information and event analysis module; Be used to analyze the concrete incident and the information of this equipment needs; This information and event analysis module comprise: GPON event analysis submodule, downlink information are analyzed submodule and GPON analyzing and processing submodule; Wherein GPON analyzing and processing submodule is used to calculate the global logic distance of this equipment, and the window of up each burst Burst frame;
Uplink frame is analyzed and rebuilding module; Be used for after the up sequential that information and event analysis module obtain rebuilding, obtaining, analyze and rebuild uplink frame; This uplink frame analysis and rebuilding module comprise a up frame head search submodule, are used for location and Count of Status, receipts packet counting and the anomalous counts of up frame head.
Preferably, said PON downlink transfer layer analysis module also is used for solving of downlink frame, decoding, frame head analysis, the parsing of PLOAM and the parsing of up BWMAP.
Preferably, said downlink information is analyzed submodule and also is used for setting up and distributes number and the ONU correspondence table, so that based on ONU state and the data of each ONU are carried out statistics and analysis.
Preferably, said GPON event analysis submodule also is used to gather the information of power level change, so that the local ONU optical module of control.
Preferably, said information and event analysis module also comprise a up sequential computing module, are used on the basis of having calculated each uplink burst Burst frame, rebuilding up sequential.
Preferably, said uplink frame analysis and rebuilding module also comprise an OLT optical module and CPA control submodule, are used to calculate resetting constantly of CPA and resetting constantly of OLT optical module.
Preferably, said uplink frame analysis and rebuilding module also comprise the physical circuit detection sub-module of makeing mistakes, and are used for the check of data parity check.
Preferably, said uplink frame analysis and rebuilding module comprise that also a uplink frame rebuilds submodule, be used for according to up frame head search submodule to the location of frame head and up sequential calculating sub module rebuild up Frame constantly and compensation lead sign indicating number.
Another technical scheme of the present invention is: a kind of distance-finding method of aforesaid light bridge equipment based on GPON, and its characteristics are that it may further comprise the steps:
S
1, said downlink information analyzes submodule and gathers the ascending idle port packets of information, obtains uplink burst Burst frame parameter, comprises protection length, leads pattern, the pattern of frame delimiter and preassignment t
Pre_EqDValue;
S
2, before the ONU serial number request, gather descending expansion Burst length information bag, record adjustment lead code length;
S
3, the ONU serial number request;
S
4, said downlink information analyzes the state that submodule is gathered descending distribution ONU identification number packets of information and set up the ONU of each subordinate;
S
5, said GPON event analysis submodule analyzes descending distance measurement request incident, the ONU in this incident as target ONU, and beginning counter, the up transmission mandate t zero hour obtains finding range from the distance measurement request incident
Ranging_Sstart
S
6, utilize up frame head to search submodule, when the up time point that finds range finding to reply the frame frame head, end counter, setting Counter Value is t
AG
S
7, said downlink information analyzes submodule target ONU gathered descending range finding temporal information bag, the balanced time delay t that obtains distributing
EqD, the global logic through this equipment of computes is apart from t
Gblr, t
Gblr=t
AG-t
Pre_EqD+ t
EqD-t
Ranging_Sstart, the unit of calculating is a bit; Repeat S
5-S
7Step, obtaining with each ONU is that the global logic of this equipment of calculating of target is apart from t
Gblr, be placed in the ONU ranging table;
S
8, said GPON analyzing and processing submodule is based on t
GblrWith the mapping of parameter upstream bandwidth, calculate the window of the up packet of search, formula is following: t
Dlmt_p=t
Gblr+ t
Sstart, unit of account is a bit, the upstream bandwidth mapping includes the uplink authorization transmission container t zero hour
Sstart, t
Dlmt_pIt is the moment of uplink frame delimiter when having found range the back operate as normal.
Preferably, step S
2In if do not expand Burst length information bag, then lead code length and calculate according to the G984.2 standard.
Preferably, step S
7The global logic of middle this equipment of selecting first target ONU to calculate and coming is apart from t
GblrAs step S
8In the basis of calculating, perhaps through asking average method to provide the t of this equipment
Gblr, and the target ONU of rejecting abnormalities calculate and the global logic of this equipment of coming apart from t
Gblr
Positive progressive effect of the present invention is: the present invention has realized the PON system of longer distance, and range upon range of through a plurality of PON light bridges can reach 40 or 60KM.The present invention is except prolonging the distance of PON; Analysis and management function also in PON, have been increased;, can find effectively the PON equipment of makeing mistakes to comprise ONU (Optical Network Unit for the precision ranging of each ONU and the monitoring of state through light bridge; Optical network unit) and the monitoring of OLT (Optical Line Terminal, optical line terminal) and each circuit delay variation.
On product was used, the present invention had prolonged the PON distance; On tester was used, the present invention strengthened development analysis, circuit uniting and adjustment and monitoring.
Embodiment
Provide preferred embodiment of the present invention below in conjunction with accompanying drawing, to specify technical scheme of the present invention.
As indicated above, because a light path transmission range of optical module is limited, so the prolongation of the distance of light bridge equipment is to be able to use a plurality of light paths through photoelectricity and electric light conversion.But according to the uplink burst Burst frame characteristics of PON, up realization photoelectricity and electric light need accurately be known the moment of burst Burst frame, simultaneously as a bridging device, uply must compensates the sign indicating number of leading that diminishes, and transmit in order to continuing past OLT.The present invention just is being based on this thought; Through detecting the ranging process between OLT and the ONU; Set up the global logic distance of bridger oneself, solved budget uplink frame problem constantly, thereby can control burst photoelectric conversion device CPA (Clock Phase Aligner effectively through calculating; The clock phase locator) and the OLT optical module, for example CPA resets constantly.Owing to correctly translate the uplink burst frame, also can compensate the sign indicating number of leading of opto-electronic conversion loss effectively.
For ease of understanding the present invention, the structure of slave unit and the operation principle of distance-finding method two aspects are introduced.
(1) the concrete structure of this equipment
As shown in Figure 1, in the left and right sides, the OLT optical module of this equipment connects the ONU optical module of next stage, and the ONU optical module connects higher level's OLT optical module.Mid portion shows several big module that this equipment comprises, is respectively PON downlink transfer layer analysis module, information and event analysis module and uplink frame analysis and rebuilding module.
Wherein, PON downlink transfer layer analysis module is reusing the descender of GPON MAC (Medium Access Control, media interviews control); Main function has solving of downlink frame, decoding, frame head analysis; PLOAM (Physical Layer Operations; Administration and Maintenance, physical layer operations administers and maintains) parsing and the parsing of up BWMAP (Bandwidth map, bandwidth mapping).
On PON downlink transfer layer analysis module basis, information and event analysis module mainly are used for analyzing concrete incident Event and the information Message that this equipment needs, and significant feature is:
1, analyzes the incident of GPON, realize by GPON event analysis submodule;
2, analyze the downlink information of GPON, analyze submodule by downlink information and realize, set up distribution ALLOCID and ONU correspondence table, so that state and the data of each ONU are carried out statistics and analysis based on ONU.
3, to carrying out the analysis of intrinsic procedure after the incident mentioned in the hereinafter operation principle and the information, realize, mainly comprise following function by GPON analyzing and processing submodule:
A, calculate the global logic distance of this equipment: mainly feed back the actual frame head moment with top incident and information and uplink frame analysis and rebuilding module.
The window of b, up each burst Burst frame;
The information of c, collection power level change is so that control local ONU optical module effectively.
The function of this GPON analyzing and processing submodule is introduced in the operation principle part with incident that relates generally to and information in detail.
4, reach the up sequential of reconstruction on the basis of having calculated each uplink burst Burst frame, realize by up sequential calculating sub module.
And uplink frame analysis and rebuilding module are obtained after the up sequential that information and event analysis module obtain rebuilding exactly, analyze and rebuild uplink frame, and concrete function is following:
A, the moment that resets of calculating the reset moment and the OLT optical module of CPA, realize by OLT optical module and CPA control submodule;
The accurate location and the Count of Status of b, up frame head are received packet counting and anomalous counts, search submodule by up frame head and realize;
The check of c, data parity check is realized by the physical circuit detection sub-module of makeing mistakes;
D, according to up frame head search submodule to the location of frame head and up sequential calculating sub module rebuild up Frame constantly and compensation lead sign indicating number, rebuild submodule by uplink frame and realize.
Can do trigger condition to above-described information and incident itself or parameter or detected makeing mistakes, the initial data of gathering up-downgoing is to external memory, so that further analyze.
(2) the distance-finding method operation principle of this equipment
This equipment makes up burst Burst frame regenerate through accurately range finding, carries out the analysis monitoring test of PON equipment and regards the light bridge use.So this method core, is promptly estimated this equipment global logic distance and the window that calculates uplink burst Burst frame in range finding.
Following step 1) to 4) mainly gets parms and each ONU state.Step 5) to 7) finds range, see Fig. 2 state transition diagram.The result that step 8) is based on preceding step calculates up frame sequential.
Step 1) is utilized downlink information to analyze submodule and is gathered ascending idle port packets of information Upstream_Overhead; It is following to obtain following uplink burst Burst frame parameter: protection guard length; Lead a yard preamble pattern, the pattern of frame delimiter delimiter and preassignment t
Pre_EqDValue (Equalization Delay, balanced time delay);
Step 2) before ONU sequence number SN request, gathers descending expansion Burst length information bag Extended_Burst_Length, write down yard Preamble length of leading of adjustment.If this packets of information is not led yard Preamble length and calculated according to the G984.2 standard, the G984.2 standard is the common practise of this area, does not do at this and gives unnecessary details;
Step 3) ONU sequence number SN request;
Step 4) is utilized downlink information to analyze submodule and is gathered descending distribution ONU identification number id information bag Assign_ONU_ID, sets up the state of the ONU of each subordinate;
The aforementioned GPON event analysis of step 5) submodule is analyzed descending distance measurement request incident Ranging_Request, the ONU in this incident as target ONU, and beginning counter..Time point A in this moment reference view 3.The up transmission mandate t zero hour obtains finding range from the distance measurement request incident
Ranging_Sstart
Step 6) ought uply find range finding to reply the time point C of frame Serial_Number_ONU frame head, utilizes up frame head to search submodule and realizes that end counter, Counter Value are t
AG
Step 7) downlink information analysis submodule is gathered the balanced time delay t that descending range finding temporal information bag Ranging_Time obtains distributing to the ONU of target
EqD, the global logic through this equipment of computes is apart from t
Gblr, its sketch map is seen Fig. 3:
t
gblr=t
AG-t
pre_EqD+t
EqD-t
ranging_Sstart;
The unit that calculates is a bit; Repeat 5)-7) step, obtaining with each ONU is that the global logic of this equipment of calculating of target is apart from t
Gblr, be placed in the ONU ranging table.Those skilled in the art generally can select first target ONU to calculate and the global logic of this equipment of coming apart from t
GblrBasis as the calculating of following step.Simultaneously also can provide the t of this equipment through asking average method
Gblr(Global Logic Reach, global logic distance), and the target ONU of rejecting abnormalities calculate and the global logic of this equipment of coming apart from t
Gblr
Step 8) GPON analyzing and processing submodule is based on t
GblrWith parameter upstream bandwidth Mapping B WMAP, the window that calculates the up packet of search is following:
t
dlmt_p=t
gblr+t
Sstart;
Unit of account is a bit; BWMAP includes uplink authorization transmission container T-CONT (Transmission Container) the t zero hour
Sstart, t
Dlmt_pIt is the uplink frame delimiter delimiter moment when having found range the back operate as normal.
By on can know; Because in the bridger design process; Some processes of OLT and ONU have been done monitoring (being information and the event analysis in the preamble); So on the basis of bridger, do collection to the various types of uplink/downlink frames between OLT and the ONU, OLT and ONU equipment analyzed thereby can be implemented in the PON system.This function has been quickened different manufacturers OLT greatly and ONU sets up the speed of intercommunication, also can analyze the problem in the exploitation effectively.
In sum, the present invention has not only expanded the distance of GPON system, and can use as test analytical instrument.And the equipment of present GPON generally is exactly common ONU, has only the coverage of 20KM, and the present invention not only uses as common ONU, also can increase service range, and the test analytical instrument that also can be used as PON uses.This equipment is fit to various PON system, comprises EPON (Ethernet Passive Optical Network, Ethernet passive optical network), GPON or the like.
In addition, external memory can be done the data acquisition under the various conditions to the data of up-downgoing, and the bag of gathering has been done relevant analysis.Further, can carry out the development and testing of PON system effectively through the analysis and the arrangement of software to initial data.
Though more than described embodiment of the present invention, it will be understood by those of skill in the art that these only illustrate, protection scope of the present invention is limited appended claims.Those skilled in the art can make numerous variations or modification to these execution modes under the prerequisite that does not deviate from principle of the present invention and essence, but these changes and modification all fall into protection scope of the present invention.