CN101431372B

CN101431372B - Method and apparatus for acquiring optical power, and optical line terminal

Info

Publication number: CN101431372B
Application number: CN200710166591XA
Authority: CN
Inventors: 杨素林; 徐之光
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2007-11-07
Filing date: 2007-11-07
Publication date: 2011-11-16
Anticipated expiration: 2027-11-07
Also published as: CN101431372A

Abstract

The invention discloses a method, a device and an OLT for obtaining optical power, belonging to the field of optical networks. The method includes: receiving uplink signals from at least two optical network units; judging whether it is necessary to obtain the optical power of the optical network units according to the identification information or upload time of the optical network units in the uplink signals, and if yes, obtaining the optical network unit's optical power Optical power. The device includes: a receiving module, a judging module and an acquiring module. An OLT includes ADC, storage and a medium access control unit, the medium access control unit is connected with the storage or with the ADC. The present invention can accurately obtain the optical power of the ONU, reduces the cost, does not need to interrupt the normal business during the acquisition, and can obtain in real time; the system is easy to expand, has good maintainability and low maintenance cost; it can also obtain selectively, and can control the start of the acquisition time and end time, which greatly improves the accuracy rate.

Description

Method and device for acquiring optical power and optical line terminal

Technical Field

The present invention relates to the field of optical networks, and in particular, to a method and an apparatus for obtaining optical power, and an optical line terminal.

Background

PON (Passive Optical Network) technology is a point-to-multipoint Optical fiber access technology. Referring to fig. 1, the PON has a tree topology, and is composed of an ODN (Optical Distribution Network), an OLT (Optical Line Terminal) on a central office side, and an ONU (Optical Network Unit) or an ONT (Optical Network Terminal) on a subscriber side. By "passive", it is meant that the ODN does not contain any active electronic devices and electronic power sources, and is composed of all passive devices, such as optical splitters (Splitter), etc., so that the PON is relatively low in management and maintenance costs.

In a Gigabit Passive Optical Network (GPON) system, a transmission direction from an OLT to an ONU is a downlink direction, and a Time-Division Multiplexing (TDM) mode is adopted, that is, downlink data is continuously transmitted, the OLT continuously broadcasts information to each ONU, and each ONU selects data reception belonging to itself. Referring to fig. 2, ONU1 selects data 1 reception in the downstream data, ONU2 selects data 2 reception in the downstream data, and so on. The transmission direction from the ONU to the OLT is an uplink direction, and a TDMA (Time-Division multiple access) manner is adopted, that is, the transmission of uplink data is bursty, different ONUs occupy different uplink Time slots, a plurality of ONUs share an uplink in a TDMA manner, and a guard Time interval for avoiding collision exists between each uplink Time slot. Referring to fig. 3, ONU1 selects one slot in the upstream slot to transmit data 1, ONU2 selects one slot in the upstream slot to transmit data 2, and so on.

In the PON network deployment and operation process, in order to better control the management system and more accurately locate a fault point and a fault reason, the burst optical power upstream of each ONU needs to be measured at the OLT end. There are currently three prior art techniques that enable measurement of optical power in bursts.

In the prior art, manual measurement is adopted, an optical cable connected with the ODN is unplugged at an OLT end, and the optical cable is directly inserted into an optical power meter, so that the uplink optical power of each ONU can be measured. In the process of implementing the present invention, the inventor finds that at least the following disadvantages exist in the prior art: manual operation is needed, and the labor cost is increased; the normal service is interrupted during measurement, and real-time measurement cannot be carried out.

The second prior art integrates a power measurement circuit into the opto-electronic module inside the OLT. Referring to fig. 4, the power supply provides power for the optoelectronic module, the mirror current source mirrors the photocurrent generated by the uplink signal at the photodiode PD into two identical paths, and one path is sent to the Data Recovery circuit, and Data Recovery is performed by modules such as TIA (trans impedance Amplifier), LA (limited Amplifier), BCDR (Burst Clock and Data Recovery), SERDES (serial/DESerialize), and GMAC (Gigabit Media Access Control); and the other path is sent to a power measurement circuit for power measurement. During measurement, the amplifier firstly amplifies the signal to be in a range suitable for measurement for subsequent sampling; an ADC (Analog-digital converter) samples a signal power value and stores the sampled value in a RAM (Random access memory); and the CPU reads the data in the RAM, and performs data processing on the sampling values for multiple times to finish the measurement of the uplink optical power. In the process of implementing the invention, the inventor finds that the second prior art has at least the following disadvantages: it is impossible to determine which ONU optical power value is currently measured, and it is impossible to selectively measure the required ONU optical power.

Both upstream frame structures of GPON and EPON (Ethernet Passive Optical Network) include source information of an upstream signal. Referring to fig. 5, a block diagram of an upstream frame of an EPON is shown. The upstream Frame includes a Preamble (Preamble), a destination address, a source address, a length/type, data, and a Frame Check Sequence (Frame Check Sequence). The length of the preamble is 8 bytes, wherein the 6 th byte and the 7 th byte are LLIDs (Logical Link IDs) which correspond to ONU-IDs of GPONs. Referring to fig. 6, a diagram of an upstream frame of GPON is shown. The uplink frame includes PLOu (Physical Layer Overhead), PLOAMu (Physical Layer operations Administration and Maintenance uplink), PLSu (power level Sequence), DBRu (Dynamic Bandwidth Report) and Payload (Payload). The PLOu includes a-byte preamble, b-byte Delimiter (Delimiter), BIP (Bit Interleaved Parity), ONU-ID, and Ind (Indication). The specific values of a and b are set by the OLT, typically 3 bytes. The specific content of the delimiter is also set by the OLT. The length of both BIP and ONU-ID is 1 byte.

In the third prior art, a power measurement circuit is integrated into an RSSI (Received Signal Strength indicator) circuit inside the OLT, and a conversion initialization module and a power calculation module are disposed in the power measurement circuit. Referring to fig. 7, the photodiode dc power supplies the optoelectronic module circuit to provide power, and the dc load provides dc bias to the photodiode; the mirror current source mirrors the photocurrent generated by the uplink signal on the photodiode into two identical paths, and one path is sent to a data recovery circuit (not shown in the figure) for recovering the transmission data; and the other path is sent to a power measurement circuit for power measurement. During measurement, the analog filtering unit filters harmful noise in the signal, and the logarithmic amplifier amplifies the signal to a proper measurement range for subsequent sampling; the analog filtering unit filters harmful noise in the signal again; a counter is integrated in the conversion initialization module, the value of the counter is the arrival time of the ONU signal to be measured, and when the counting time of the counter is up, the conversion initialization module triggers the analog/digital converter to sample the power value of the signal; and finally, calculating a plurality of sampling values obtained by the analog/digital converter by a power calculation module to obtain the optical power of the burst uplink signal. In the process of implementing the invention, the inventor finds that the third prior art has at least the following disadvantages: the estimated time of the signal arrival of the ONU to be measured needs to be written into a counter inside the conversion initialization module in advance, and the counter triggers the analog/digital converter to sample the signal according to the time.

Disclosure of Invention

In order to accurately obtain the uplink optical power of an ONU in a PON system, embodiments of the present invention provide a method and an apparatus for obtaining optical power, and an optical line terminal. The technical scheme is as follows:

in one aspect, a method for obtaining optical power is applied to a point-to-multipoint passive optical network communication system, and the method includes:

receiving uplink signals from at least two optical network units;

judging whether the optical power of the optical network unit needs to be acquired or not according to the identification information or the uploading time of the optical network unit in the uplink signal, and if so, acquiring the optical power of the optical network unit;

wherein the determining whether the optical power of the optical network unit needs to be acquired according to the identification information or the uploading time of the optical network unit in the uplink signal includes:

analyzing a photocurrent signal generated by the uplink signal at a photodiode, extracting optical network unit identification information in the current uplink signal, comparing the extracted optical network unit identification information with optical network unit identification information corresponding to a pre-stored uplink signal to be detected, and if the extracted optical network unit identification information is consistent with the pre-stored optical network unit identification information, judging that the optical power of the optical network unit needs to be acquired; or,

and acquiring the uploading start time of the optical network unit in the received uplink signal, judging whether the acquired uploading start time of the optical network unit is the uploading start time of the optical network unit to be detected according to the uploading start time value of the optical network unit to be detected stored in the counter, and if so, judging that the optical power of the optical network unit needs to be acquired, wherein the uploading start time of the optical network unit to be detected is acquired before the uplink signal is received and is stored in the counter.

In another aspect, an optical line terminal for performing the method of obtaining optical power as described above includes:

the device comprises an analog-digital converter, a memory, a medium access control unit and a data processing unit;

the media access control unit is connected with the memory and used for judging whether the optical power of the optical network unit needs to be acquired or not according to the identification information or the uploading time of the optical network unit in the uplink signal in the passive optical network communication system, and if so, triggering the memory to store the signal sampled by the analog-digital converter;

the data processing unit is used for performing data processing on the signals sampled by the analog-digital converter to obtain optical power and outputting the optical power to the memory, and the data processing unit is respectively connected with the analog-digital converter and the memory.

the media access control unit is connected with the analog-digital converter and used for judging whether the optical power of the optical network unit needs to be acquired or not according to the identification information or the uploading time of the optical network unit in the uplink signal in the passive optical network communication system, and if so, triggering the analog-digital converter to sample;

The technical scheme has the following beneficial effects:

and judging whether the optical power of the ONU in the uplink signal in the passive optical network communication system needs to be acquired or not through the identification information or the uploading time, and if so, acquiring the optical power of the ONU. The manual operation is not needed, so that the labor cost is reduced; normal service is not required to be interrupted during acquisition, and real-time acquisition is realized; the system is convenient to expand, the flexibility of application is improved, the maintainability of the system is good, and the maintenance cost is low.

Drawings

FIG. 1 is a schematic diagram of a tree topology of a PON system in the prior art;

fig. 2 is a schematic diagram of TDM mode transmission in the downlink direction in a GPON system in the prior art;

FIG. 3 is a schematic diagram of the transmission in the uplink TDMA mode in the GPON system in the prior art;

FIG. 4 is a schematic diagram of a prior art structure for obtaining optical power;

fig. 5 is a block diagram of an upstream frame of an EPON in the prior art;

fig. 6 is a structural diagram of an upstream frame of GPON in the prior art;

FIG. 7 is a schematic diagram of a prior art optical power acquisition configuration;

FIG. 8 is a flow chart for obtaining optical power provided by an embodiment of the present invention;

fig. 9 is a flowchart of a method for obtaining optical power according to embodiment 1 of the present invention;

fig. 10 is a schematic structural diagram of a GMAC trigger RAM in the method provided in embodiment 1 of the present invention;

fig. 11 is a schematic structural diagram of adding a data processing module in the method according to embodiment 1 of the present invention;

fig. 12 is a flowchart of a method for obtaining optical power according to embodiment 2 of the present invention;

fig. 13 is a schematic diagram of a GMAC-triggered ADC structure in the method provided in embodiment 2 of the present invention;

fig. 14 is a schematic structural diagram of adding a data processing module in the method according to embodiment 2 of the present invention;

fig. 15 is a flowchart of a method for obtaining optical power according to embodiment 3 of the present invention;

fig. 16 is a schematic diagram of an OLT allocating a time slot to a T-CONT according to embodiment 3 of the present invention;

fig. 17 is a structural diagram of an apparatus for obtaining optical power according to embodiment 4 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to fig. 8, according to the identification information or the upload time of the optical network unit in the uplink signal in the passive optical network communication system, the embodiment of the present invention determines whether the optical power of the optical network unit in the uplink signal needs to be acquired, and if so, acquires the optical power of the ONU.

Example 1

Referring to fig. 9, an embodiment of the present invention provides a method for acquiring optical power, which is applied to a point-to-multipoint passive optical network communication system, and in this embodiment, a method for determining whether to acquire optical power of an ONU in a received uplink signal according to identification information is adopted, and a method for starting to record a sampled signal after determining that acquisition is required is performed by sampling and determining whether to acquire the ONU according to an identification is adopted, which specifically includes the following steps:

step 101: receiving uplink signals from at least two ONUs in the PON, carrying out power sampling on the received uplink signals, and extracting identification information of the ONUs from the received uplink signals;

sampling can be realized by using an ADC (analog to digital converter), referring to fig. 10, the ADC in the power measurement circuit is respectively connected with an amplifier and an RAM (random access memory), the amplifier amplifies a photocurrent signal generated by an uplink signal at the PD (potential difference) and then the ADC samples the amplified signal to obtain a sampling signal;

the identification information of the ONU can be ID information of the ONU; the ID information of the ONU can be extracted through a data recovery circuit in a photoelectric module in the OLT; referring to fig. 10, the data recovery circuit analyzes the photocurrent signal generated by the uplink signal at the PD through TIA, LA, BCDR, SERDES, and GMAC, and may extract the ONU ID information in the current uplink signal; for example, the 6 th byte and the 7 th byte of a preamble of an EPON uplink frame are extracted, and the ID information of the ONU is extracted from the bytes; or extracting a byte positioned behind the BIP in the PLOu of the GPON, namely the ID information of the ONU;

step 102: judging whether the optical power of the ONU corresponding to the extracted identification information needs to be acquired, if so, executing step 103; otherwise, ending;

referring to fig. 10, ID information of an ONU corresponding to an uplink signal to be detected may be pre-stored in a GMAC in the data recovery circuit, and after extracting ID information of a current uplink signal, the GMAC compares the pre-stored ID information with the extracted ID information, and if the pre-stored ID information is consistent with the extracted ID information, the current uplink signal is an uplink signal of the ONU to be detected;

step 103: recording the sampled signals;

the acquired sampling signal can be stored in the RAM, referring to fig. 10, the ADC is connected to the RAM, an amplifier is connected in front of the ADC, the RAM is connected to the GMAC, and when the GMAC confirms that the optical power of the ONU corresponding to the extracted ID information needs to be acquired, the RAM is triggered to start storing the signal acquired by sampling the ADC;

step 104: carrying out data processing on the recorded sampling signal to obtain optical power;

the data processing process can be completed by a CPU, referring to fig. 10, the CPU is connected to a RAM, the CPU reads a plurality of sampling signals stored in the RAM, and performs data processing on the read sampling signals to obtain optical power; for example, the CPU performs an averaging operation on the read sampling signal to obtain the optical power.

Further, the method may further include the step of controlling the acquired time:

and when the uplink signal corresponding to the extracted identification information is finished or reaches the preset time, stopping recording the sampled signal obtained by sampling, and finishing recording.

The preset time is an acquisition ending time preset as required, and is usually not longer than the duration of the uplink signal, for example, if one uplink signal lasts for 100us, the time for stopping recording can be preset to 80us, that is, recording is stopped when the uplink signal does not end.

In the method, a mode of comparing first and then processing data is adopted, and in practical application, a mode of comparing first and then processing data can also be adopted, specifically as follows:

receiving uplink signals from at least two ONUs in the PON, extracting identification information of the ONUs from the received uplink signals, and judging whether optical power of the ONUs corresponding to the extracted identification information needs to be acquired or not; simultaneously, sampling the received uplink signal, and performing data processing on the sampled signal to obtain optical power; and if the optical power needs to be acquired, acquiring the optical power obtained by data processing.

Further, in this way, a step of controlling the acquisition time may be added:

and when the uplink signal corresponding to the extracted identification information is finished or reaches the preset time, stopping acquiring the optical power obtained by data processing.

For example, referring to fig. 11, an amplifier in the power measurement circuit is connected to an ADC, a data processing module is added between the ADC and the RAM, the amplifier amplifies a signal output by the mirror current source, the ADC samples the signal amplified by the amplifier, and the data processing module processes the signal sampled by the ADC to obtain optical power; when GMAC judges that the light power needs to be obtained, the light power value obtained by the data processing module is obtained and stored in the RAM; when the acquisition is finished, the optical power value stored in the RAM may be one or more, and if the optical power value is more than one, the CPU reads all the optical power values and performs corresponding data processing (e.g., averaging again) to obtain the required optical power.

In this embodiment, whether the optical power of the ONU needs to be obtained is determined by sampling the received uplink signal and extracting the identification information of the ONU from the received uplink signal, and if so, the optical power obtained by performing data processing according to the sampled signal is obtained. The acquisition precision can be better than one microwatt, and the acquisition time can be less than one microsecond; the method can support the acquisition of the optical power of all ONUs in the PON system with 128 ONUs within the time of one upstream frame. Moreover, manual operation is not needed, and the labor cost is reduced; normal service is not required to be interrupted during acquisition, and real-time acquisition is realized; the system expansion is convenient, and the application flexibility is improved; when a new ONU is added to the PON, the related configuration does not need to be added, the maintainability of the system is good, and the maintenance cost is low. In addition, the required optical power of the ONU can be selectively acquired, and the acquisition starting time can be accurately controlled; by setting the stopping time and stopping when the uplink signal is ended, the acquiring ending time can be accurately controlled, so that the accuracy of acquiring the optical power is greatly improved. When the mode of firstly processing the data and then judging the data is adopted, the processing time of the CPU to the data can be saved, the occupancy rate of the CPU is reduced, and the influence on the service is reduced.

Example 2

Referring to fig. 12, an embodiment of the present invention further provides a method for acquiring optical power, which is applied to a point-to-multipoint passive optical network communication system, in this embodiment, a manner of determining whether to acquire optical power of an ONU in a received uplink signal according to identification information is adopted, and a manner of determining first and then triggering sampling after determining that acquisition is required is adopted, and specifically, the method includes the following steps:

step 201: receiving uplink signals from at least two ONUs in the PON, and extracting identification information of the ONUs from the received uplink signals;

step 202: judging whether the optical power of the ONU corresponding to the extracted identification information needs to be acquired, if so, executing step 203; otherwise, ending;

step 203: sampling a current uplink signal;

step 204: and carrying out data processing on the sampled signal obtained by sampling to obtain the optical power.

and when the uplink signal corresponding to the extracted identification information is finished or reaches the preset time, stopping sampling the uplink signal.

The preset time is usually not longer than the duration of the uplink signal, i.e. the sampling is stopped when the uplink signal is not finished.

When controlling the acquired time, the step of data processing may be performed after the sampling is finished, or may be performed during the sampling. The first mode is specifically as follows: when the fact that the optical power needs to be acquired is judged, sampling is carried out on the uplink signal corresponding to the extracted identification information until the uplink signal is finished or the preset time is up, and then data processing is carried out on the sampled signal to obtain the optical power; the second mode is specifically as follows: when the uplink signal is judged to be acquired, sampling the uplink signal corresponding to the extracted identification information, performing data processing on the sampled signal to obtain optical power until the uplink signal is finished or the preset time is up, and acquiring the optical power obtained by the data processing.

For example, referring to fig. 13, the data recovery circuit extracts ID information of an uplink signal, and determines whether to acquire optical power of an ONU corresponding to the ID according to the ID information, if so, the GMAC triggers the ADC in the power measurement circuit to start sampling a signal amplified by the amplifier, the sampled signal is stored in the RAM until the sampling is finished, and then the CPU reads the sampled signal stored in the RAM and performs data processing to obtain the optical power.

For example, referring to fig. 14, the data recovery circuit extracts ID information of an uplink signal, and determines whether to acquire optical power of an ONU corresponding to the ID information according to the ID information, if so, the GMAC triggers an ADC in the power measurement circuit to start sampling a signal amplified by an amplifier, and after sampling, the data processing module performs data processing on the sampled signal to obtain optical power, and stores the optical power in the RAM until the data processing and storing are finished; then CPU reads the light power stored in RAM, if a plurality of them are read, then carries on the corresponding data processing (such as taking average value), obtains the needed light power.

In this embodiment, whether the optical power of the ONU needs to be acquired is determined by extracting the identification information of the ONU from the received uplink signal, and if so, the current uplink signal is sampled, and then the sampled signal is subjected to data processing, so as to obtain the optical power. The acquisition precision can be better than one microwatt, and the acquisition time can be less than one microsecond; the method can support the acquisition of the optical power of all ONUs in the PON system with 128 ONUs within the time of one upstream frame. Moreover, manual operation is not needed, and the labor cost is reduced; normal service is not required to be interrupted during acquisition, and real-time acquisition is realized; the system expansion is convenient, and the application flexibility is improved; when a new ONU is added to the PON, the related configuration does not need to be added, the maintainability of the system is good, and the maintenance cost is low. In addition, the required optical power of the ONU can be selectively acquired, and the acquisition starting time can be accurately controlled; by setting the stopping time and stopping when the uplink signal is ended, the acquiring ending time can be accurately controlled, so that the accuracy of acquiring the optical power is greatly improved. When the data processing mode is adopted in the acquisition process, the processing time of the CPU on the data can be saved, the occupancy rate of the CPU is reduced, and the influence on the service is reduced.

Referring to fig. 10 and 11, in embodiment 1, the GMAC trigger RAM is used to store the signal sampled by the ADC or store the signal obtained after data processing, and compared with the GMAC trigger ADC used to sample in embodiment 2, the control is easier and the efficiency is higher. Referring to fig. 13 and 14, since the GMAC triggers the ADC and also triggers the RAM, two devices need to be controlled simultaneously, and after triggering, data needs to be written into the RAM after the ADC is stabilized, so that the control is complicated and long-term. And the mode that GMAC directly triggers RAM overcomes the defect and is easy to realize.

Example 3

Referring to fig. 15, an embodiment of the present invention further provides a method for acquiring optical power, which is applied in a point-to-multipoint passive optical network communication system, and determines whether optical power of an ONU needs to be acquired according to upload start time of the ONU in a received uplink signal by allocating a time slot in advance, specifically including the following steps:

step 301: the GMAC of the OLT allocates a fixed time slot for each T-CONT (transmission container) in the PON according to a DBA (Dynamic Bandwidth Assignment) algorithm, each ONU can comprise one or more T-CONT, and the time slot allocated to the T-CONT determines the uploading start time and the uploading end time of the ONU so as to determine the uploading sequence of the ONUs.

The T-CONT can be distinguished by Alloc-ID (distribution identification), and the Alloc-ID and the ONU have unique corresponding relation. For example, referring to fig. 16, an Alloc-ID of 1 represents a time slot allocated for T-CONT1 (i.e., ONU1), an upload start time of 100, and an upload end time of 300; the Alloc-ID is 2 and represents the time slot allocated for the T-CONT2 (namely ONU2), the uploading starting time is 400, and the uploading ending time is 500; an Alloc-ID of 3 represents the time slot allocated for T-CONT3 (i.e., ONU3), the upload start time is 520, and the upload end time is 600.

Step 302: the OLT receives uplink signals from at least two ONUs in the PON and samples the received uplink signals;

step 303: the OLT acquires the uploading starting time of the ONU in the received uplink signal.

If the ONU to be tested is known, the upload start time of the ONU to be tested can be acquired before receiving the uplink signal, and the upload start time is stored in the timer or the counter. Further, the uploading end time of the ONU to be tested may be obtained and stored in a timer or a counter, for example, the uploading start time of the ONU to be tested is stored in a first timer, and the uploading end time of the ONU to be tested is stored in a second timer.

Step 304: judging whether the optical power of the ONU needs to be acquired or not according to the acquired uploading start time of the ONU, and if so, executing a step 305; otherwise, ending.

For example, whether the acquired upload start time of the ONU is the upload start time of the ONU to be measured is determined according to the upload start time value of the ONU to be measured stored in the counter, and if so, the step of acquiring the optical power is performed.

Step 305: and recording the sampled signals, such as storing the sampled signals in a RAM.

For example, referring to fig. 10, an ADC in the OLT is connected to a RAM, an amplifier is connected in front of the ADC, and when it is determined that optical power needs to be acquired according to the upload start time, the GMAC triggers the RAM to start storing a signal sampled by the ADC.

Step 306: the recorded sampling signal is processed to obtain the optical power, and the data processing process can be completed by the CPU.

For example, referring to fig. 10, a CPU is connected to a RAM, and the CPU reads a plurality of sampling signals stored in the RAM and performs data processing on the read sampling signals to obtain optical power; for example, the CPU performs an averaging operation on the read plurality of sampling signals to obtain the optical power.

Further, the method may further include:

and in the process of acquiring the optical power, judging whether the uploading end time of the current uplink signal is reached or the preset time is reached, if so, stopping recording the sampled signal, and finishing the acquisition. The preset time is usually not longer than the duration of the current uplink signal, that is, the sampling is stopped when the uplink signal is not finished.

In the method, a mode of triggering recording of the sampling signal when the optical power needs to be acquired is adopted, and in practical application, a mode of triggering recording of the optical power when the optical power needs to be acquired can also be adopted, specifically as follows:

receiving uplink signals from at least two ONUs, sampling the received uplink signals, and performing data processing on the sampled signals to obtain optical power; and when the optical power of the ONU in the current uplink signal needs to be acquired, recording the optical power obtained by data processing.

In this way, the work of data processing can be handled by a separate added data processing module. For example, referring to fig. 11, an amplifier in a power measurement circuit of the OLT is connected to an ADC, a data processing module is added between the ADC and the RAM, the amplifier amplifies a signal output by a mirror current source, the ADC samples the signal amplified by the amplifier, and the data processing module processes the signal sampled by the ADC to obtain optical power; when the optical power of the ONU in the current uplink signal needs to be acquired, acquiring an optical power value obtained by the data processing module and storing the optical power value in the RAM; the CPU reads the optical power value from the RAM.

In addition, further, in the process of acquiring the optical power, when the uploading ending time is reached or the preset time is reached, the optical power obtained by recording the data processing is stopped, and the acquisition is ended. The preset time is usually not longer than the duration of the upstream signal of the current ONU. For example, referring to fig. 11, when the upload end time of the ONU in the current uplink signal reaches, the optical power value obtained by the data processing module stops being obtained, that is, the RAM stops storing the optical power, at this time, the optical power value stored in the RAM may be one or multiple, the CPU reads all the optical power values stored in the RAM, and if the optical power values are multiple, the CPU performs corresponding data processing (e.g., averaging again) to obtain the required optical power.

Further, in this embodiment, the optical power may also be obtained by triggering sampling of the uplink signal when it is determined that the optical power of the ONU in the current uplink signal needs to be obtained, which is specifically as follows:

receiving uplink signals from at least two ONUs, acquiring uplink starting time of the ONUs in the received uplink signals, judging whether optical power of the ONUs needs to be acquired, if so, sampling the uplink signals of the ONUs, and performing data processing on the sampled signals to obtain the optical power. The data processing may be executed by the CPU, or may be executed by a separate data processing module.

For example, referring to fig. 13, when it is determined that the optical power of the current ONU needs to be obtained, the GMAC triggers the ADC to sample the uplink signal of the current ONU, the RAM stores the signal sampled by the ADC, and the CPU performs data processing after reading out the signal to obtain the optical power of the ONU. Referring to fig. 14, when it is determined that the optical power of the current ONU needs to be obtained, the GMAC triggers the ADC to sample the uplink signal of the current ONU, the data processing module performs data processing on the signal sampled by the ADC to obtain the optical power, and the RAM stores the optical power obtained by the data processing module and the optical power read by the CPU.

In this way, further, in the process of acquiring the optical power, it may be determined whether the uploading end time of the current uplink signal is reached or a preset time is reached, and if so, the sampling is stopped, and the acquisition is ended. The preset time is usually not longer than the duration of the upstream signal of the current ONU.

In this embodiment, each ONU in the PON is allocated with a fixed upload time in advance, and whether the optical power of the ONU in the uplink signal needs to be acquired is determined according to the upload start time of the received uplink signal, and if so, the optical power of the ONU is acquired. The acquisition precision can be better than one microwatt, and the acquisition time can be less than one microsecond; the method can support the acquisition of the optical power of all ONUs in the PON system with 128 ONUs within the time of one upstream frame. Moreover, manual operation is not needed, and the labor cost is reduced; normal service is not required to be interrupted during acquisition, and real-time acquisition is realized; the system expansion is convenient, and the application flexibility is improved. In addition, the required optical power of the ONU can be selectively acquired, and the acquisition start time and the acquisition end time can be accurately controlled, so that the acquisition accuracy is greatly improved. The data processing is carried out on the sampling signals, the data processing can be carried out in the uploading time, the data processing can also be carried out when the uploading time is finished, and the application is more flexible.

Example 4

Referring to fig. 17, an embodiment of the present invention further provides a device for acquiring optical power, which is applied to a point-to-multipoint passive optical network communication system, and specifically includes:

the receiving module is used for receiving uplink signals from at least two optical network units;

the judging module is used for judging whether the optical power of the optical network unit needs to be acquired or not according to the identification information or the uploading time of the optical network unit in the uplink signal received by the receiving module;

and the obtaining module is used for obtaining the optical power of the optical network unit when the judgment result of the judging module is yes.

Wherein, the judging module specifically includes:

the extracting unit is used for extracting the identification information of the optical network unit from the uplink signal received by the receiving module;

and the judging unit is used for judging whether the optical power of the optical network unit corresponding to the identification information extracted by the extracting unit needs to be acquired or not.

Further, the above apparatus further comprises:

the distribution module is used for distributing a fixed time slot for each optical network unit in the passive optical network communication system, and the starting time of the time slot corresponds to the uploading starting time;

the judging module is specifically configured to judge whether the optical power of the optical network unit in the uplink signal needs to be acquired according to the upload start time of the uplink signal received by the receiving module.

Further, the above apparatus further comprises:

the sampling module is used for sampling the uplink signal received by the receiving module;

correspondingly, the obtaining module specifically includes:

the acquisition unit is used for acquiring a signal sampled by the sampling module when the judgment result of the judgment module is yes;

and the processing unit is used for carrying out data processing on the signals acquired by the acquisition unit to obtain the optical power.

Further, the above apparatus further comprises:

the sampling and processing module is used for sampling the uplink signal received by the receiving module and processing the sampled signal to obtain optical power;

correspondingly, the obtaining module is specifically configured to obtain the optical power obtained by the sampling and processing module when the judgment result of the judging module is yes.

In addition, the obtaining module specifically includes:

the sampling unit is used for sampling the uplink signal, and when the judgment result of the judgment module is yes, the sampling unit samples the uplink signal;

and the processing unit is used for carrying out data processing on the sampling signal obtained by the sampling unit to obtain the optical power.

Further, the apparatus further comprises:

and the control module is used for judging whether the uploading ending time of the uplink signal is reached or the preset time is reached in the process of acquiring the optical power of the optical network unit by the acquisition module, and if so, informing the acquisition module of stopping acquiring the optical power of the optical network unit.

In this embodiment, the determining module determines whether the optical power of the ONU in the current uplink signal needs to be acquired, and if so, the acquiring module acquires the optical power of the ONU. The acquisition precision can be better than one microwatt, and the acquisition time can be less than one microsecond; the method can support the acquisition of the optical power of all ONUs in the PON system with 128 ONUs within the time of one upstream frame. Moreover, manual operation is not needed, and the labor cost is reduced; normal service is not required to be interrupted during acquisition, and real-time acquisition is realized; the system expansion is convenient, and the application flexibility is improved; when a new ONU is added to the PON, the related configuration does not need to be added, the maintainability of the system is good, and the maintenance cost is low. In addition, the required optical power of the ONU can be selectively acquired, and the acquisition starting time can be accurately controlled; the acquisition of the optical power is stopped when the uploading end time is reached or the preset time is reached, so that the acquired end time can be accurately controlled, and the accuracy of acquiring the optical power is greatly improved. When the data processing mode is adopted in the acquisition process, the processing time of the CPU on the data can be saved, the occupancy rate of the CPU is reduced, and the influence on the service is reduced.

Example 5

Referring to fig. 10, an embodiment of the present invention further provides an OLT (optical line terminal) for acquiring optical power, including an ADC (analog-to-digital converter), a memory, and a media access control unit, where the media access control unit is further connected to the memory, and is configured to determine whether optical power of an ONU needs to be acquired according to identification information or upload time of the ONU in an uplink signal in a passive optical network communication system, and if so, trigger the memory to store a signal sampled by the media access control unit. The ADC is connected with the amplifier, and the ADC samples signals amplified by the amplifier during sampling.

Further, referring to fig. 11, the OLT may further include:

and the data processing unit is used for carrying out data processing on the signals sampled by the ADC to obtain optical power and outputting the optical power to the memory, and the data processing unit is respectively connected with the ADC and the memory. Accordingly, the RAM stores the optical power obtained by the data processing unit.

In addition, referring to fig. 13, an embodiment of the present invention further provides an OLT for measuring burst optical power, including an ADC, a memory, and a medium access control unit, where the medium access control unit is connected to the ADC, and is configured to determine whether to acquire optical power of an ONU according to identification information or upload time of the ONU in an uplink signal in a passive optical network communication system, and if so, trigger the ADC to perform sampling. The ADC is connected with the amplifier, and the ADC samples signals amplified by the amplifier during sampling.

Further, referring to fig. 14, the OLT may further include:

and the data processing unit is used for carrying out data processing on the signals sampled by the ADC to obtain optical power and outputting the optical power to the memory, and the data processing unit is respectively connected with the ADC and the memory. Accordingly, the memory stores the optical power obtained by the data processing unit.

In this embodiment, the medium access control unit may determine whether to acquire optical power according to the identification information, that is, extract the identification information of the ONU from the uplink signal of the PON, and determine whether to acquire the optical power of the ONU corresponding to the identification information; in addition, the medium access control unit may also adopt a method of allocating a time slot in advance, that is, the medium access control unit allocates a fixed time slot to each ONU in the PON, where a start time of the time slot is an upload start time, and an end time of the time slot is an upload end time, and the medium access control unit determines whether to acquire optical power of the ONU in the uplink signal according to the upload start time of the current uplink signal.

In this embodiment, the memory may be specifically a RAM (random access memory), and the media access control unit may be specifically a GMAC (gigabit media access control unit).

In the OLT in this embodiment, by increasing a connection relationship between the media access control unit and the component memory or the ADC in the power measurement circuit, when the media access control unit determines that the optical power of the ONU in the current uplink signal needs to be acquired, the media access control unit triggers the memory or triggers the ADC to acquire the optical power. The acquisition precision can be better than one microwatt, and the acquisition time can be less than one microsecond; the method can support the acquisition of the optical power of all ONUs in the PON system with 128 ONUs within the time of one upstream frame. Moreover, manual operation is not needed, and the labor cost is reduced; normal service is not required to be interrupted during acquisition, and real-time acquisition is realized; the system expansion is convenient, and the application flexibility is improved; when a new ONU is added to the PON, the related configuration does not need to be added, the maintainability of the system is good, and the maintenance cost is low. In addition, the required optical power of the ONU can be selectively acquired, and the acquisition starting time can be accurately controlled; by stopping storing or sampling when the uploading end time arrives or the preset time arrives, the acquired end time can be accurately controlled, and the acquisition accuracy is greatly improved. When a mode of increasing the data processing unit to process data in the acquisition process is adopted, the processing time of the CPU to the data can be saved, the occupancy rate of the CPU is reduced, and the influence on the service is reduced.

In the embodiment of the present invention, the manner of storing in the power measurement circuit by using a separate memory device may be replaced by: the memory is integrated in the media access control unit, and the media access control unit triggers the ADC to sample or triggers the internal memory to store according to the requirement.

In the embodiment of the invention, when the memory is used for storing the sampling signal, the read-write state of the memory can be set, and when data is written into the memory, the read-write state is set; when data is read from the memory, the data is set to a read state; and the rest time is set to be in a non-read-write state, so that the accuracy of the system can be improved. For example, referring to fig. 10 and 11, the RAM is initially set to a non-read-write state, when the GMAC triggers the RAM and writes data into the RAM, the RAM is set to a write state, and after the write is completed, the non-read-write state is recovered; when the CPU reads data from the RAM, the data is set to be in a read state, and after the data is read, the data is restored to be in a non-read-write state.

The embodiment of the present invention can be implemented by combining software and hardware, and the corresponding software program can be stored in a readable storage medium, such as a hard disk or a cache of the OLT.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A method for obtaining optical power, applied to a point-to-multipoint passive optical network communication system, the method comprising:

receiving uplink signals from at least two optical network units;

2. The method of deriving optical power according to claim 1, further comprising:

after receiving uplink signals from at least two optical network units, sampling the uplink signals;

correspondingly, the acquiring the optical power of the optical network unit specifically includes:

and acquiring the sampled signal, and performing data processing on the acquired sampled signal to obtain the optical power of the optical network unit.

3. The method of deriving optical power according to claim 1, further comprising:

after receiving uplink signals from at least two optical network units, sampling the uplink signals, and performing data processing on the sampled signals to obtain optical power;

correspondingly, the obtaining the optical power of the optical network unit specifically includes:

and acquiring the optical power obtained by processing the data.

4. The method according to claim 1, wherein the obtaining the optical power of the onu specifically includes:

and sampling the uplink signal, and performing data processing on the sampled signal to obtain optical power.

5. The method of deriving optical power according to claim 1, further comprising:

and in the process of acquiring the optical power of the optical network unit, judging whether the uploading ending time or the preset time of the uplink signal is reached, and if so, stopping acquiring the optical power of the optical network unit.

6. An optical line terminal for performing the method of obtaining optical power of claim 1, comprising:

7. An optical line terminal for performing the method of obtaining optical power of claim 1, comprising: