Abstract:
An apparatus comprising an individual optical power level calculation (IOPLC) module and a transceiver coupled to the IOPLC module and configured to communicate with a plurality of optical network units (ONUs). Also disclosed is an apparatus comprising a control and management (CM) module, an average power level measurement (APLM) module coupled to the CM module, a first transceiver coupled to the CM module and configured to communicate with an optical line terminal (OLT), and a second transceiver coupled to the CM module and the APLM module, and configured to communicate with a plurality of ONUs.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. application Ser. No. 12/276,578 filed Nov. 24, 2008 by Frank J. Effenberger, et al. and entitled “Burst Power Measurements Using Averaged Power Measurement,” which claims the benefit of U.S. Provisional Patent Application No. 61/018,800 filed Jan. 3, 2008 by Frank J. Effenberger, et al. and entitled, “Burst Power Measurements Using Averaged Power Measurement,” both of which are incorporated herein by reference as if reproduced in their entirety. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     REFERENCE TO A MICROFICHE APPENDIX 
     Not applicable. 
     BACKGROUND 
     A passive optical network (PON) is one system for providing network access over “the last mile.” The PON is a point to multi-point network comprised of an optical line terminal (OLT) at the central office, an optical distribution network (ODN), and a plurality of optical network units (ONUs) at the customer premises. The ODN comprises optical fibers, couplers, splitters, distributors, filters, and other passive optical devices, which connect the OLT to the ONUs. A PON may be a long reach PON (LR-PON), where the OLT and the ONUs may communicate along longer distances in comparison with other PONs. An LR-PON may comprise an Extender Box, which may be coupled to the OLT and the ONUs. The Extender Box may amplify the optical signals forwarded between the OLT and the ONUs and along at least some of the other LR-PON components. As such, the amplified optical signals may be less affected by increased signal attenuations, which are introduced at the various LR-PON components, along longer distances between the OLT and the ONUs. 
     SUMMARY 
     In one embodiment, the disclosure includes an apparatus comprising an individual optical power level calculation (IOPLC) module and a transceiver coupled to the IOPLC module and configured to communicate with a plurality of ONUs. 
     In another embodiment, the disclosure includes an apparatus comprising a control and management (CM) module, an average power level measurement (APLM) module coupled to the CM module, a first transceiver coupled to the CM module and configured to communicate with an OLT, and a second transceiver coupled to the CM module and the APLM module, and configured to communicate with a plurality of ONUs. 
     In yet another embodiment, the disclosure includes a method comprising at least one processor configured to implement a method comprising obtaining a plurality of average power levels over a plurality of time intervals for a plurality of burst power levels corresponding to a plurality of optical signals from a plurality of ONUs, obtaining a plurality of timeslots associated with the optical signals, and determining values for the burst power levels using the average powers levels, the time intervals, and the timeslots. 
     These and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of this disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts. 
         FIG. 1  is a schematic diagram of an embodiment of a PON. 
         FIG. 2  is a schematic diagram of an embodiment of an OLT. 
         FIG. 3  is a schematic diagram of an embodiment of an Extender Box. 
         FIG. 4  is a chart showing the power levels and time lengths of a plurality of transmissions. 
         FIG. 5  is a flowchart of an embodiment of a burst power level estimation method. 
         FIG. 6  is a schematic diagram of one embodiment of a general-purpose computer system. 
     
    
    
     DETAILED DESCRIPTION 
     It should be understood at the outset that although an illustrative implementation of one or more embodiments are provided below, the disclosed systems and/or methods may be implemented using any number of techniques, whether currently known or in existence. The disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated below, including the exemplary designs and implementations illustrated and described herein, but may be modified within the scope of the appended claims along with their full scope of equivalents. 
     Disclosed herein is a method and system for estimating a plurality of unknown burst power levels corresponding to a plurality of optical signals, which may be transmitted from a plurality of ONUs in a PON. The burst power levels may be estimated based on a plurality of known average power levels. The average power levels may be measured over a plurality of corresponding time intervals at an Extender Box coupled to the ONUs and an OLT without using timing information for the individual optical signals. Accordingly, the average power levels and the corresponding time intervals may be processed, in addition to bandwidth information, to calculate the unknown burst power levels corresponding to the ONUs. Specifically, a plurality of timeslots may be obtained based on the bandwidth information, and may be associated with the corresponding unknown burst power levels. The sum of the individual products of the unknown burst power levels and the corresponding timeslots may be equated to a product of one known average power level and one corresponding time interval to obtain one equation. As such, a plurality of equations, corresponding to each measured average power level, may be obtained and processed using a numerical procedure to obtain the unknown burst power levels. Once obtained, the burst power levels may be analyzed to assess the performances of or detect problems in the individual ONUs. 
       FIG. 1  illustrates one embodiment of a PON  100 . The PON  100  may comprise an OLT  110 , an optical trunk line (OTL)  120 , an Extender Box  130 , an ODN  140 , and a plurality of ONUs  150 . The PON  100  may be a communications network that does not require any active components to distribute data between the OLT  110  and the ONUs  150 . Instead, the PON  100  may use the passive optical components in the ODN  140  to distribute data, in the form of optical signals, between the OLT  110  and the ONUs  150 . Examples of suitable PONs  100  include the asynchronous transfer mode PON (APON) and the broadband PON (BPON) defined by the ITU-T G.983 standard, the Gigabit PON (GPON) defined by the ITU-T G.984 standard, the Ethernet PON (EPON) defined by the IEEE 802.3ah standard, and the wavelength division multiplexing PON (WDM-PON). Further, the PON  100  may be an LR-PON, where the optical signals forwarded between the OLT  110  and the ONU  150  may be amplified, for instance using the Extender Box  130 , to tolerate increased signal attenuations introduced along increased distances between the OLT  110  and the ONUs  150 . 
     The OLT  110  may be any device that is configured to communicate with the ONUs  150  and another network (not shown). Specifically, the OLT  110  may act as an intermediary between the other network and the ONUs  150 . In an embodiment, the OLT  110  may communicate with the network using a server network interface (SNI) and with the ONUs  150  or other components of the PON  100  coupled to the ONUs  150  using a send/receive point or interface (S/R). The OLT  110  may forward data received from the network to the ONUs  150  and forward data received from the ONUs  150  onto the other network. For instance, the OLT  110  may forward the data in the form of optical signals to the ONUs  150  and in the form of electrical or radio signals to the network. Although the specific configuration of the OLT  110  may vary depending on the type of PON  100 , in an embodiment, the OLT  110  may comprise a transmitter, a receiver, a transceiver, or combinations thereof. When the other network is using a protocol, such as Ethernet or Synchronous Optical Networking (SONET)/Synchronous Digital Hierarchy (SDH), that is different from the communications protocol used in the PON  100 , the OLT  110  may comprise a converter that converts the other network&#39;s data into the PON&#39;s protocol. The converter may also convert the PON&#39;s data into the other network&#39;s protocol. The OLT  110  may be located at a central location, such as a central office, but may be located at other locations as well. 
     The OTL  120  may be a single optical fiber or a plurality of aggregated fibers coupled to the OLT  110  and the Extender Box  130 . In an alternative embodiment, the OTL  120  may be configured similar to the ODN  140  and comprise optical fibers, couplers, splitters, distributors, filters, other passive optical devices, or combinations thereof. 
     The Extender Box  130  may be configured to receive, amplify, and retransmit or forward the optical signals between the OLT  110  and the ONUs  150 . Specifically, the Extender Box  130  may act as a signal booster or regenerator for the optical signals, which may be transported over longer distances or through more optical components with respect to other PONs, such as in an LR-PON. For instance, the Extender Box  130  may comprise a repeater or amplifier, such as an optical-electrical-optical (OEO) converter or a semiconductor optical amplifier (SOA) inserted between the OTL  120  and the ODN  140 . In an embodiment, the Extender Box  130  may exchange the optical signals with the OTL  120  using an interface to the trunk (IFT), and exchange the optical signals with the ODN  140  using an interface to the distribution (IFD). Further, the Extender Box  130  may comprise a transmitter, a receiver, a transceiver, other modules, or combinations thereof. 
     The ODN  140  may be a data distribution system that may comprise optical fiber cables, couplers, splitters, distributors, and/or other equipment. In an embodiment, the optical fiber cables, couplers, splitters, distributors, and/or other equipment are passive optical components. Specifically, the optical fiber cables, couplers, splitters, distributors, and/or other equipment may be components that do not require any power to distribute data as optical signals between the OLT  110  and the ONUs  150 . The ODN  140  may extend from the Extender Box  130  to the ONUs  150  in a branching configuration or in any alternative configuration. 
     The ONUs  150  may be any devices that are configured to communicate with the OLT  110  and at least one customer or user (not shown). Specifically, the ONUs  150  may act as an intermediary between the OLT  110  and the customer. For instance, the ONUs  150  may forward data received from the OLT  110  to the customer and forward data received from the customer onto the OLT  110 . In an embodiment, the ONUs  150  may exchange the optical signals with the ODN  140  using a receive/send point or interface (R/S), and exchange the optical signals with the customer using a user network interface (UNI). Although four ONUs  150  are shown in  FIG. 1 , the PON  100  may comprise any number of ONUs  150 . 
     Although the specific configuration of the ONUs  150  may vary depending on the type of PON  100 , in an embodiment, the ONUs  150  may comprise an optical transmitter configured to send optical signals to the OLT  110 . Additionally, the ONUs  150  may comprise an optical receiver configured to receive optical signals from the OLT  110  and a converter that converts the optical signal into electrical signals for the customer, such as signals in the asynchronous transfer mode (ATM) or Ethernet protocol. The ONUs  150  may also comprise a second transmitter and/or receiver that may send and/or receive the electrical signals to a customer device. In some embodiments, the ONUs  150  and optical network terminals (ONTs) are similar, and thus the terms are used interchangeably herein. The ONUs  150  may be located at distributed locations, such as the customer premises, but may be located at other locations as well. 
     The optical signals transmitted from the ONUs  150  may be burst optical signals, e.g., optical signals that are transmitted intermittently or separated by time delays or pauses, which may have signal power levels referred to as burst power levels. In normal operating conditions, the burst power levels of the transmitted optical signals may be equal to at least one power level associated with the transmitters&#39; standard performances at the ONUs  150 . However, when the operating condition at an ONU  150  deteriorates due to a decrease in the transmitters&#39; performance, the burst power level may decrease or may fluctuate over time. Hence, measuring the burst power level corresponding to the optical signal may be advantageous to assess the performance of the ONU  150  or to detect a problem in the ONU  150  or the transmitter. 
     However, measuring the burst power levels of the optical signals at the OLT  110  may be difficult in the PON  100  in the presence of the Extender Box  130 . Specifically, the transmitted optical signals from the ONUs  150  may be amplified at the Extender Box  130  at variable amplification levels, for instance due to design or physical limitations, before being forwarded to the OLT  110 . Thus, it may be difficult to correlate the power levels of the amplified optical signals received at the OLT  110  with the burst power levels of the optical signals transmitted from the ONUs  150 . Hence, measuring the power levels of the amplified optical signals at the OLT  110  may not be an accurate evaluation of the burst power levels of the optical signals from the ONUs  150 . Moreover, the burst power levels of the optical signals may not be directly measured at the Extender Box  130 . Specifically, the Extender Box  130  may not be configured to implement a PON protocol, for instance to reduce the impact of adding the Extender Box  130  on system design. Hence, the Extender Box  130  may be configured as a passive device, which may not associate the individual burst power levels with the corresponding optical signals. 
     To overcome the difficulty in measuring the burst power levels of the optical signals at the OLT  110  or associating the optical signals with corresponding ONUs  150  at the Extender Box  130 , a plurality of average power levels corresponding to the optical signals may be measured at the Extender Box  130 . The average power levels may be measured over a plurality of corresponding time intervals or durations, which may each comprise the total time for receiving at least some of the optical signals at the Extender Box  130 . In an embodiment, the measured average power levels and the corresponding time intervals may then be forwarded from the Extender Box  130  to the OLT  110 , where they may be processed, in addition to timing information, to evaluate or estimate the corresponding burst power levels for the transmitted optical signals from the individual ONUs  150 . Specifically, the timing information may be needed to associate the burst power levels with the corresponding ONUs  150 . For instance, the timing information may comprise a plurality of timeslots or durations corresponding to the transmitted optical signals. In an embodiment, the timing information may be obtained from bandwidth information, which may be stored at the OLT  110 . The bandwidth information may be historic bandwidth information, which may be acquired by recording the time bandwidth of previously transmitted optical signals from the ONUs  150 . Hence, the timing information or timeslots may be extracted from the recorded time bandwidth. Alternatively, the bandwidth information may be statistical bandwidth information, which may be obtained based on anticipated traffic from the ONUs  150 , historic traffic in the PON  100 , or both. 
       FIG. 2  illustrates one embodiment of an OLT  200 , which may be used to estimate the burst power levels at a PON, such as the PON  100 . The OLT  200  may comprise an IOPLC module  210 , which may be coupled to a PON adapter  220  and a transceiver  230 . The IOPLC module  210  may be configured to evaluate or calculate the burst power levels using the average power levels and the corresponding time intervals, which may be obtained from the Extender Box  130 , and the timing information, which may be stored in the OLT  200 . In an embodiment, the IOPLC module  210  may be a software, hardware, firmware, or combinations thereof, which may be programmed to receive as inputs the average power levels, the time intervals, and the timeslots corresponding to the burst power levels. Hence, the IOPLC  210  may process the inputs based on an algorithm or program to provide the burst power levels as outputs. 
     The PON adapter  220  may be coupled to a server or a network, for instance via an SNI, and may be used to exchange data between the OLT  200  and the server or network. For instance, the PON adapter  220  may forward at least some of the inputs or outputs of the IOPLC  210 , including the burst power levels, to a network operator or manager in charge of detecting problems in the PON&#39;s ONUs. Additionally, the PON adapter  220  may exchange other data, including data received from the ONUs, with the server or network. Accordingly, the PON adapter  220  may convert the exchanged data based on the protocols and the transport layer architectures of the OLT  200  and the network. In some embodiments, the PON adapter  220  may comprise a transmitter, receiver, transceiver, or combinations thereof. 
     The transceiver  230  may be coupled, for instance via an S/R, to an Extender Box, which may be in turn coupled to the ONUs. The transceiver  230  may be an integrated device comprising an optical transmitter and receiver or alternatively may comprise an optical transmitter coupled to an optical receiver. The transceiver  230  may be used to exchange data between the OLT  200  and the Extender Box, as well as the ONUs. For instance, the transceiver  230  may forward the average power levels and the time intervals from the Extender Box to the IOPLC  210 . Additionally, the transceiver  230  may forward data between the OLT  200  and the ONUs via the Extender Box. 
       FIG. 3  illustrates one embodiment of an Extender Box  300 , which may be used to measure the average power levels of the optical signals transmitted from a plurality of ONUs, such as the ONUs  150  described above. The Extender Box  300  may comprise a CM module  310 , an average power level measurement (APLM) module  320 , a first transceiver  330 , which may be coupled to the CM module  310 , and a second transceiver  340 , which may be coupled to the CM module  310  and the APLM module  320 . The CM module  310  may be configured to set the time intervals over which the average power levels may be measured. For instance, the CM module  310  may set a plurality of about equal or different time intervals for measuring a plurality of average signals. In some embodiments, the CM module  310  may set a discrete number equal to the quantity of the average power levels to be measured, a discrete number equal to the quantity of burst power levels to be detected for each average power level, or both. The CM module  310  may forward the time intervals, and in some embodiments the discrete numbers, to the APLM module  320  via the second transceiver  340 . For instance, the CM module  310  may comprise a software, hardware, firmware, or combinations thereof, which may be programmed to provide the time intervals as an input to the APLM module  320 . In other embodiments, the CM module  310  may be configured to receive such measurement settings via the first transceiver  330 , for instance from an OLT coupled to the Extender Box  300 , and to forward it to the APLM module  320 . 
     The APLM module  320  may be configured to measure the average power levels over the time intervals set by the CM module  310 . To measure each of the average power levels, the APLM module  320  may receive a plurality of optical signals from the individual ONUs, via the second transceiver  340 , and detect the corresponding individual burst power levels. For instance, the APLM module  320  may detect a quantity of burst power levels equal to the discrete number set by the CM module  310 . Hence, the APLM module  320  may sum the burst power levels, and divide the sum by the discrete number to obtain a corresponding average power level. Alternatively, the APLM module  320  may detect and average a plurality of burst power levels in a continuous manner over the time interval, for instance using a low pass filter. The APLM module  320  may comprise at least a software, hardware, firmware, or combinations thereof, which may be programmed to receive, as inputs, the burst power levels and provide, as outputs, the average power levels, which may then be forwarded to the CM module  310 , via the second transceiver  340 . In turn, the CM module  310  may forward the average power levels and the corresponding time intervals to the OLT, via the first transceiver  330 . 
     The first transceiver  330  and the second transceiver  340  may be integrated devices comprising a plurality of optical transmitters and receivers or alternatively may comprise a plurality of optical transmitters coupled to a plurality of optical receivers. The first transceiver  330  may be coupled to an OLT, for instance via an IFT, and may be used to exchange data between the OLT and the Extender Box  300 . For instance, the first transceiver  330  may forward at least some of the inputs or outputs of the CM module  310 , as described above. Additionally, the first transceiver  330  may exchange other data, including data received from the ONUs, with the OLT. The second transceiver  340  may be coupled, for instance via an IFD, to an ODN, which may be in turn coupled to the ONUs. The second transceiver  340  may be used to detect the burst power levels of the optical signals. For instance, the second transceiver  340  may comprise an optical detector, such as a detector array, a photodiode, or other types of detectors, which may detect the strength or power of the optical signal, or convert the optical signal into an electrical signal, which may be measured. The second transceiver  340  may also exchange data between the ONUs and the Extender Box  300  or the OLT, in addition to the measurements described above. For instance, the second transceiver  340  may forward the data from the ONUs and the average power levels from the APLM module  320 , via the CM module  310 , to the first transceiver  330 , which may in turn forward it to the OLT. 
     In other embodiments, instead of measuring the average power levels at the Extender Box  300  and forwarding the average power levels to the OLT  200  to estimate the burst power levels, the OLT may forward to the Extender Box the timing information, bandwidth information, or timeslots needed to estimate the burst power levels. Accordingly, the Extender Box may comprise an IOPLC module in addition to the APLM module  320 . The Extender Box may receive the needed information from the OLT, measure the average power levels, and estimate the burst power levels using the average power levels, the corresponding time intervals, and the received timeslots. In alternative embodiments, the Extender Box may send the sum of the detected power levels to the OLT. Accordingly, the OLT may comprise an APLM module  320  in addition to the IOPLC module, and may evaluate the average power levels and estimate the burst power levels. 
       FIG. 4  illustrates one embodiment of a plurality of burst optical signals, including a first burst optical signal  410 , a second burst optical signal  420 , and an nth burst optical signal  430 , which may be detected over a time interval equal to about T i . The nth burst optical signal  430  may be the last detected burst optical signal in a sequence of n burst optical signals, where n may be equal to an integer or a discrete number set by a CM module. The time interval T i  may be equal to the time interval, for instance set by a CM module, over which an average power of the ONUs&#39; optical signals may be measured. The burst power levels of the burst optical signals may be detected at about equal or different values by the optical detector. For instance, the first burst optical signal  410 , the second burst optical signal  420 , and the nth burst optical signal  430  may have a first burst power level equal to about P 1 , a second burst power level equal to about P 2 , and an nth burst power level equal to about P n , respectively. The burst power levels of the detected burst optical signals may be summed and divided by the quantity of the detected burst optical signals to measure or obtain the average power level. For instance, a total of n values, including P 1 , P 2 , and P n , may be summed up and divided by n to obtain a value of P a  for the average power level. 
     Further, each detected burst optical signal may be associated with a timeslot, for instance using bandwidth information, which may be a portion of the time interval T i . For instance, the first burst optical signal  410 , the second burst optical signal  420 , and the nth burst optical signal  430  may be associated with a first timeslot T i1 , a second timeslot T i2 , and an nth timeslot T in , respectively. The timeslots T i1 , T i2 , T in , as well as the remaining timeslots corresponding to the remaining detected burst optical signals over the time interval T i , may or may not be about equal to one another. The time interval T i  may include other time portions, in addition to the timeslots corresponding to the detected burst optical signals, such as time gaps that may exist between the timeslots. The time gaps may correspond to time durations where no burst power levels may be detected or no burst optical signals may be transmitted. 
     The burst power levels corresponding to the ONUs&#39; optical signals may be estimated, for instance at the IOPLC, using the average power levels measurements and based on a plurality of mathematical equations. The mathematical equations may define the relationship between the burst power levels, which may be unknown variables, with the corresponding timeslots, the average power levels, and the corresponding time intervals, which may be known values. If there are a sufficient number of equations to resolve the unknown variables, the mathematical equations may be solved to obtain values for the burst power levels. For example, the mathematical equations may comprise a system of n mathematical equations that relate n unknown burst power levels and n known average power levels, where n is an integer. Specifically, a total or sum of the products of each burst power level and its corresponding timeslot may be equated to a product of one average power level and its corresponding time interval. The system of n mathematical may be represented in a generic form, such as:
 
( P   1   ×T   i1 )+( P   2   ×T   i2 )+ . . . +( P   (n-1)   ×T   i(n-1) )+( P   n   ×T   in )= Pa   i   ×T   i .
 
For instance, the above equation may be the ith equation in the system of n equations, where Pa i  is the ith average power level, T i  is the ith corresponding time interval, P 1 , P 2 , . . . , P (n-1) , and P n  are n burst power levels, T i1 , T i2 , . . . , T i(n-1) , and T in  are n corresponding timeslots, n is equal to the number of burst power levels, and i is an integer less than or equal to the number of average power levels. The number of average power levels may be equal to or greater than n, e.g., the number of the unknown burst power levels to be estimated. Increasing the number of measured average power levels may reduce the amount of errors or uncertainties in the calculated burst power levels, for instance due to measurement errors or noise from the optical detector. Further, each average power level may be measured a plurality of times or repeatedly at a predetermined rate over the time interval, which may be set by the CM module. The measured values may then be averaged to obtain an average power level value with less error or uncertainty, and hence more accurate burst power level values.
 
     The n equations may be solved simultaneously using standard solution methods or any solution methods that may be used to obtain the values of the burst power levels from the average power levels. The standard solution methods may include statistical solution methods, linear and non-linear regression techniques, least error solutions, or any other solution methods that may be used to solve the burst power levels. For instance, using a least error solution, the estimated values of the burst power levels may correspond to an acceptable fitting error for the measured average power levels. In other words, using the least error solution, the obtained values of the burst power levels may correspond to measurement values that are substantially equal to the acquired values of the average power levels. 
     In another embodiment, one burst power level for an optical signal from a single ONU may be estimated without estimating the remaining burst power levels. The burst power level may be estimated using two equations that represent the relation between the unknown burst power levels for all the optical signals from the ONUs, with two measured average power levels. Specifically, the burst power level may be estimated based on a first average power level measured over a first time interval and a second average power level measured over a second time interval, which may be consecutive to the first time interval. Further, the burst power level may be associated with a first timeslot during the first time interval and a second timeslot during the second time interval, which may not be equal to the first timeslot. For instance, the second timeslot may be longer than the first timeslot. However, the remaining burst power levels may be associated with corresponding timeslots which may be about equal during the first time interval and the second time interval. The system of two equations may be represented such as:
 
( P   1   ×T   11 )+( P   2   ×T   12 )+ . . . +( P   (n-1)   ×T   1(n-1) )+( P   n   ×T   1n )= Pa   1   ×T   1  
 
( P   1   ×T   21 )+( P   2   ×T   22 )+ . . . +( P   (n-1)   ×T   2(n-1) )+( P   n   ×{T   2n +δ})= Pa   2   ×T   2 ,
 
wherein Pa 1  is the first average power level, T 1  is the first time interval, Pa 2  is the second average power level, T 2  is the second time interval, P n  is the burst power level, T 1n  is the first timeslot at the first time interval, {T 2n δ} is the second timeslot at the second time interval, and δ is equal to about the time difference between the second timeslot and the first timeslot. Additionally, P 1 , P 2 , . . . , and P n-1  are the remaining burst power levels, T 11 , T 12 , . . . , and T 1(n-1)  are the corresponding timeslots at the first time interval, T 21 , T 22 , . . . , and T 2(n-1)  are the corresponding timeslots at the second time interval, and n is equal to the number of burst power levels.
 
       FIG. 5  illustrates an embodiment of a burst power level estimation method  500 , which may be used in a PON system comprising an Extender Box, such as an LR-PON. The burst power level estimation method  500  may be implemented at the OLT. Alternatively, the burst power level estimation method  500  may be implemented at another PON component in communication with the OLT, such as the Extender Box. At block  510 , the burst power level estimation method  500  may obtain a plurality of average power levels, which may be measured at the Extender Box, and at least one time interval. For instance, the average power levels and the time interval may be forwarded from the Extender Box to the OLT via an OTL. Alternatively, the average power levels and the time interval may be obtained and stored within the Extender Box, for instance from the APLM and CM modules. 
     At block  520 , the burst power level estimation method  500  may obtain a plurality of timeslots corresponding to the burst power levels, for instance from historic or statistical bandwidth information. The bandwidth information may be stored at the OLT or may be forwarded from a network server or manager to the OLT, which may also receive the average power levels and the time interval. Alternatively, the bandwidth information or timeslots may be forwarded from the OLT to the Extender Box, where the average power levels and the time interval may be obtained and stored. 
     At block  530 , the relation between the burst power levels, the timeslots, the average power levels, and the time intervals may be established, for instance using a system of mathematical equations, as described above. The system of mathematical equations may comprise a number of equations equal to the number of measured average power levels, and equal to or greater than the number of unknown burst power levels. Additionally or alternatively, another system of equations, comprising at least two equations, may be established to estimate the value of any burst power level associated with a selected ONU, as described above. 
     At block  540 , the relation or system of equations that relates the unknown burst power levels to the measured average power levels and the other known values may be processed or solved to calculate or resolve at least one of the burst power levels, as described above. The system of equations may be established and solved at the OLT, for instance using an IOPLC module. Alternatively, the an IOPLC module may be present at or coupled to the Extender Box, where the burst power levels may be estimated, and then forwarded to the OLT. Additionally, the burst power levels may optionally be forwarded to other PON components, such as the ONUs or a PON component in charge of monitoring or detecting problems in the ONUs. 
     The network components described above may be implemented on any general-purpose network component, such as a computer or network component with sufficient processing power, memory resources, and network throughput capability to handle the necessary workload placed upon it.  FIG. 6  illustrates a typical, general-purpose network component  600  suitable for implementing one or more embodiments of the components disclosed herein. The network component  600  includes a processor  602  (which may be referred to as a central processor unit or CPU) that is in communication with memory devices including secondary storage  604 , read only memory (ROM)  606 , random access memory (RAM)  608 , input/output (I/O) devices  610 , and network connectivity devices  612 . The processor  602  may be implemented as one or more CPU chips, or may be part of one or more application specific integrated circuits (ASICs). 
     The secondary storage  604  is typically comprised of one or more disk drives or tape drives and is used for non-volatile storage of data and as an over-flow data storage device if RAM  608  is not large enough to hold all working data. Secondary storage  604  may be used to store programs that are loaded into RAM  608  when such programs are selected for execution. The ROM  606  is used to store instructions and perhaps data that are read during program execution. ROM  606  is a non-volatile memory device that typically has a small memory capacity relative to the larger memory capacity of secondary storage  604 . The RAM  608  is used to store volatile data and perhaps to store instructions. Access to both ROM  606  and RAM  608  is typically faster than to secondary storage  604 . 
     At least one embodiment is disclosed and variations, combinations, and/or modifications of the embodiment(s) and/or features of the embodiment(s) made by a person having ordinary skill in the art are within the scope of the disclosure. Alternative embodiments that result from combining, integrating, and/or omitting features of the embodiment(s) are also within the scope of the disclosure. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a numerical range with a lower limit, R 1 , and an upper limit, R u , is disclosed, any number falling within the range is specifically disclosed. In particular, the following numbers within the range are specifically disclosed: R=R 1 +k*(R u −R 1 ), wherein k is a variable ranging from 1 percent to 100 percent with a 1 percent increment, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . , 50 percent, 51 percent, 52 percent, . . . , 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Moreover, any numerical range defined by two R numbers, as defined in the above, is also specifically disclosed. Use of the term “optionally” with respect to any element of a claim means that the element is required, or alternatively, the element is not required, both alternatives being within the scope of the claim. Use of broader terms such as comprises, includes, and having should be understood to provide support for narrower terms such as consisting of, consisting essentially of, and comprised substantially of. Accordingly, the scope of protection is not limited by the description set out above but is defined by the claims that follow, that scope including all equivalents of the subject matter of the claims. Each and every claim is incorporated as further disclosure into the specification and the claims are embodiment(s) of the present disclosure. The discussion of a reference in the disclosure is not an admission that it is prior art, especially any reference that has a publication date after the priority date of this application. The disclosure of all patents, patent applications, and publications cited in the disclosure are hereby incorporated by reference, to the extent that they provide exemplary, procedural, or other details supplementary to the disclosure. 
     While several embodiments have been provided in the present disclosure, it should be understood that the disclosed systems and methods might be embodied in many other specific forms without departing from the spirit or scope of the present disclosure. The present examples are to be considered as illustrative and not restrictive, and the intention is not to be limited to the details given herein. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted, or not implemented. 
     In addition, techniques, systems, subsystems, and methods described and illustrated in the various embodiments as discrete or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown or discussed as coupled or directly coupled or communicating with each other may be indirectly coupled or communicating through some interface, device, or intermediate component whether electrically, mechanically, or otherwise. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the spirit and scope disclosed herein.