CN104618052A

CN104618052A - Gibabit-Capable (GPON) optical line terminal (OLT) light module interface circuit

Info

Publication number: CN104618052A
Application number: CN201410852787.4A
Authority: CN
Inventors: 王侃; 许国威; 胥小均; 王彦伟
Original assignee: Shenzhen Gongjin Electronics Co Ltd
Current assignee: Shenzhen Gongjin Electronics Co Ltd
Priority date: 2015-03-09
Filing date: 2015-03-09
Publication date: 2015-05-13
Anticipated expiration: 2035-03-09
Also published as: CN104618052B

Abstract

The invention discloses a GPON OLT light module interface circuit. The circuit comprises a light component, a reset unit and a limiting amplifier. A golden finger interface pointer of the interface circuit is consistent with an Ethernet Passive Optical Network (EPON) OLT. According to the interface circuit, a level switching module is arranged at an eight pin, and a signal input port can be set into an SD state through the level switching module on HOST in the GPON system pattern. Internal reset clock signals are input in the limiting amplifier, an alarm generator shapes middle alarm signals output by the limiting amplifier into emergency alarm signals to be output to PIN8 and input in the reset unit, and the reset clock signal frequency is not lower than 50 M. By means of the interface circuit, the system RESET timing problem can be cast aside completely, and accordingly, the GPON OLT light module has good system compatibility.

Description

A kind of interface circuit of GPON OLT optical module

Technical field

The present invention relates to PON OLT optical module field, particularly the common version of a kind of EPON OLT system and GPON OLT system designs optical module interface circuit.

Background technology

Design today of high speed development at IC, the integration degree of IC is more and more higher, and the chip of close agreement also can be total to inside version IC to one by compatible design.In PON (passive optical-fiber network Passive optical network) system, common version can be adopted to design at the master chip MAC of ONU (Optical Network Unit optical node) terminal at present, a design can be applied in different Access Network agreements simultaneously, i.e. EPON(Ethernet Passive Optical Network Ethernet passive optical network optical link local side) and GPON(Gigabit-Capable PON gigabit passive optical network optical link local side) agreement.

For operator, the hardware facility of upgrade of network will be the upgrading of equipment of a very huge engineering, particularly local side and terminal equipment, no matter manpower, or financial resources are all very large expenses, current ONU terminal has achieved the design of common version, and on some network provider, start application.But at OLT (optical line terminal optical line terminal) local side, also do not come into effect the common version design of OLT system, but this will be a trend, particularly for the network provider newly entered, in the EPON scheme that first stage of construction can adopt cost relatively low, but along with user is to the surge of web database technology, wish to use the GPON scheme carrying more big data quantity, but for local side OLT, still do not support the optical module scheme of the common version OLT system of EPON and GPON, reason is: the hardware protocol of the PON interface of OLT system is different, as shown in Figures 1 and 2.The RESET(of the golden finger of GPON OLT resets) signal is positioned at PIN7, RSSI Trigger (instruction of receiving light power degree triggers) signal is positioned at PIN9, the PIN7 of the golden finger of EPON OLT is then RSSI Trigger, because the difference of the hardware interface of above-mentioned two signals, design being difficult to adopt the hardware and software of common version, even if software simulating reluctantly, that also will bring the unsteadiness hidden danger on Software for Design.If adopt hardware interface compatible design, to be a huge convenience undoubtedly, the OLT optical module that carry opto-electronic conversion also needs to adapt to this version design altogether, make two kinds of OLT optical modules also can hardware interface compatible, solve the RESET signal of GPON OLT optical module and EPON OLT optical module and the incompatible problem of RSSI Trigger PIN.

On the other hand, the reason that can not set foot in OLT optical module field for a lot of optical module manufacturer is the matching problem that there is sequential between OLT system and OLT optical module, if correct timing Design cannot be realized, so OLT system is by cisco unity malfunction, but in general this sequential is rest in OLT system business hand, cannot obtain for general manufacturer, even if obtain, also need to carry out actual Interoperability Testing, otherwise still cannot ensure normal use, OLT system resource is then a huge threshold.The timing Design of each OLT system manufacturer is not quite similar, so the multiple timings compatibility issue of OLT optical module is also a challenge, and this sequential is the design of a nanosecond.How solving multi-vendor sequence problem, realizing being the key issue that OLT applies smoothly.In OLT sequential, comprise RESET sequential and RSSI Trigger sequential, RESET sequential is then the most difficult.

Summary of the invention

The GPON OLT optical module interface circuit that the common version that the object of the invention is to propose a kind of compatible EPON OLT system and GPON OLT system designs.

Technical scheme of the present invention is a kind of interface circuit of GPON OLT optical module, the optical assembly comprised, reset unit, limiting amplifier, this interface circuit golden finger interface pointer is consistent with EPON OLT, in this interface circuit: the 8th pin is provided with level handover module, in EPON system pattern, by the mainboard flat handover module that powers on, signal input is arranged to los state; At GPON system pattern, by the mainboard flat handover module that powers on, signal input is arranged to SD state.Mainboard can complete switching by software or hardware.Internal reset clock signal is input in limiting amplifier, the middle alarm signal that limiting amplifier exports by alarm maker outputs to PIN8 after being shaped to burst alarm signal, be input in the reset unit exported in reset unit, reset clock signal frequency is not less than 50M simultaneously.

By above this design, just cast aside the sequence problem of system RESET completely, thus make GPON OLT optical module have better system compatibility, and reach the object of EPON OLT and the common version of GPON OLT system, reduce the equipment construction cost of operator, for later grid is upgraded the convenience provided very.

Below in conjunction with specific embodiment, the present invention is described in more detail.

Accompanying drawing explanation

Fig. 1 is current GPON OLT golden finger interface pinouts.

Fig. 2 is current EPON OLT golden finger interface pinouts.

Fig. 3 is GPON OLT golden finger interface pinouts of the present invention.

Fig. 4 is conduction reset diagram before GPON OLT.

Fig. 5 is conduction reset timing figure before GPON OLT.

Fig. 6 is GPON OLT GUARD Time formula reset diagram.

Fig. 7 is GPON OLT GUARD Time formula sequential chart.

Fig. 8 is the reset diagram in the general GPON OLT of the embodiment of the present invention.

Fig. 9 is the sequential chart in the general GPON OLT of the embodiment of the present invention.

Embodiment

Embodiment 1, as shown in Figure 3, the present embodiment proposes a kind of solution of the novel GPON OLT optical module without outside RESET, the interface circuit of this GPON OLT optical module compatible GPON OLT optical module and EPON OLT optical module simultaneously simultaneously, hardware interface compatibility is to EPON system and GPON system, to form edition system design altogether, it is a kind of general GPON OLT optical module.The maximum advantage of this general GPON OLT optical module is its design without outside RESET, with the sequential compatibling problem of multiple OLT system manufacturer by without the need to considering, will bring facilitate greatly to application.

Owing to adopting the mode designed without outside RESET, so be no longer reserved with the input pin of RESET on the hardware interface of the golden finger of optical module, i.e. PIN 7 pin, consider the hardware interface definition of EPON system again, by the hardware In-put design of RSSI Trigger on PIN 7, the hardware interface of such two kinds of agreement optical modules is unified by realization, and the PIN 9 of former RSSI Trigger can be connected to ground.PIN 8 pin in EPON OLT system is los state, and PIN 8 pin in GPON OLT system is SD pin, and both both can realize unified at this, also still can keep the design of former level logic, in the application, by the switching of HOST software simulating level.

RESET sequential on the GPON OLT optical module of current main flow has the following two kinds: one is front conduction RESET sequential, and one is GUARD Time formula RESET sequential.

Front conduction RESET sequential: as shown in Figure 4,5, reset is arranged on leading the inside, be directly inputted to Reset Unit(reset unit) and Burst mode LA(burst mode limiting amplifier), the decision level of reset signal reset burst luminous signal, be positioned at the leading time of light signal, after reset completes, Burst SD(happens suddenly alarm) set up.

GUARD Time formula RESET sequential: as shown in Figure 6, Figure 7; reset is arranged on guard time(guard time) in; reset is directly inputted to Burst mode LA(burst mode limiting amplifier); reset Burst SD; and Burst mode LA exports Reset form LA to Reset Unit simultaneously; the decision level of reset burst luminous signal, after light signal is set up, Burst SD sets up.

Due to the complete difference of above two kinds of RESET sequential, there is the not same sex completely, to be determined to use any sequential by OLT system, just so, a kind of solution of the novel GPON OLT optical module without outside RESET is proposed in this patent, because without the intervention of outside RESET signal, so the problem of sequential can not become key issue, be illustrated in fig. 6 shown below.In this design, no longer include the existence of outside RESET signal, then on the hardware interface of the golden finger of this optical module, save RESET input pin, therefore can unify with the hardware interface of EPON OLT.Because the sequential of the nanosecond of GPON OLT, if do not have RESET signal to remove reset Reset Unit and Burst mode LA, what then cannot meet light signal sets up sequential, therefore RESET signal must be produced by inside, but the sequential of ONU is not fixing, so the RESET signal of a real-time sequence of timing really cannot be arranged for each uplink burst bag data.For this kind of situation, the RESET signal being input to Burst mode LA is the clock signal that frequency is not less than 50M, the level of signal meets Transistor-Transistor Logic level, Burst mode LA is in continuous reset mode, when there being burst input light, the signal A that Burst mode LA exports equally also is the Transistor-Transistor Logic level signal close to clock signal frequency, signal A is through SD generator(alarm signal generator) after produce Burst SD, SD generator produces RESET signal Reset from SD generator simultaneously and is input to the decision level that Reset Unit removes reset burst luminous signal, when not happening suddenly input light, the signal A that Burst mode LA exports will be low level, signal A produces alarm level after SD generator, and SD generator produces RESET signal Reset from SD generator simultaneously and is input to the decision level that Reset Unit carries out reset burst luminous signal.

Claims

1. an interface circuit for GPON OLT optical module, the optical assembly comprised, reset unit, limiting amplifier, is characterized in that:

This interface circuit golden finger interface pointer is consistent with EPON OLT,

In this interface circuit:

8th pin is provided with level handover module, by the mainboard flat handover module that powers on, signal input is arranged to SD state;

Internal reset clock signal is input in limiting amplifier, the middle alarm signal that limiting amplifier exports by alarm maker outputs to the 8th pin after being shaped to burst alarm signal, be input in the reset unit exported in reset unit, reset clock signal frequency is not less than 50M simultaneously.

2. the interface circuit of GPON OLT optical module according to claim 1, is characterized in that: described optical assembly is burst mode optical assembly.

3. the interface circuit of GPON OLT optical module according to claim 1, is characterized in that: described limiting amplifier is the limiting amplifier of burst mode.

4. the interface circuit of GPON OLT optical module according to claim 1, is characterized in that: mainboard utilizes hardware level handover module that the 8th pin is arranged to SD state.

5. the interface circuit of GPON OLT optical module according to claim 1, is characterized in that: mainboard utilizes software level handover module that the 8th pin is arranged to SD state.