Method for diagnosing inteference in a termination device of a passive optical communications network, and corresponding computer program and device

Abstract

In using a passive optical network comprising an OLT (10) connected to a plurality of ONUs through a tree architecture, it can occur that some of the ONUs, or the OLT itself, malfunction, sometimes to the extent that they have to be replaced. These malfunctions negatively affect the operation of the network and consequently user experience quality. There is therefore a need to detect and characterise the impact of these malfunctions on the operation of the network. The present invention provides a method for diagnosing interference which makes it possible to evaluate the impact of a change in the transmission power (EOPT1, EOPT2) for an optical signal (SO, TS) for one termination device (50-1, 50-2, 70-i) belonging to a PON on the other termination devices of the PON, in particular for the purpose of evaluating possibilities for parametrically optimising the termination devices.

Description

[0001] DESCRIPTION

[0002] TITLE: Method for establishing a diagnosis of disturbances in a terminating device of a passive optical communication network, computer program product and corresponding device

[0003] Field of invention

[0004] The invention relates to the field of passive optical networks or PON networks (for “Passive Optical Network” in English).

[0005] More particularly, the invention relates to a technique for establishing a diagnosis of disruption of communications generated by a PON termination device on at least one other termination device.

[0006] The invention applies more particularly, but not exclusively, to new generation optical networks of the G-PON type (defined according to the ITU-T G.984 standard), NG-PON or NG-PON-2 (defined according to the ITU-T G.989 standard) or XGS-PON (defined according to the ITU-T G.9807 standard).

[0007] Prior art and its drawbacks

[0008] In recent years, increasing user demands for bandwidth and quality of service have prompted researchers to develop new architectures and protocols for optical communication networks.

[0009] PON architecture is a passive point-to-multipoint architecture that provides high-speed optical access to a primarily residential user population located at a distance (typically over several tens of kilometers). This architecture is characterized by the absence of active equipment along the network branches connecting the optical exchange to the user modules.

[0010] Traditionally, a PON network 100 comprises, as illustrated in [Fig. 1], an optical line terminal (or OLT for “Optical Line Terminal”) 10 located at the optical exchange (or CO for “Central Office”) connected to an optical coupler 30 by a first optical fiber 20, as well as a set of user modules (or ONU for “Optical Network Unit”) referenced ONU-1 to ONU-n (n being able to go up to 64). The user modules ONU-1 to ONU-n are respectively connected to the coupler 30 by means of dedicated optical fibers 40-1 to 40-n.

[0011] The OLT 10 transmits a downlink optical signal to the ONUs and each ONU transmits an uplink optical signal to the OLT in its own time slot. In order for the OLT 10 to be able to identify the uplink optical signal specific to each ONU, a transmission schedule is previously imposed on each ONU. The OLT is therefore configured to optically serve the ONUs via the fiber 20 passively shared via the coupler / combiner 30 according to a 1 to n topology and a defined communication schedule.

[0012] During the operation of a passive optical network, some ONUs or the OLT itself sometimes malfunction to the point of needing to be replaced. These malfunctions negatively impact the operation of the network and, consequently, the quality of user experience.

[0013] There is therefore a need to detect and qualify the impact of these malfunctions on the operation of the network.

[0014] The present invention proposes to resolve all or part of these drawbacks.

[0015] Presentation of the invention The invention meets this need by proposing a method for establishing a diagnosis of disturbances generated by at least a first termination device, located at one end of a first branch of a passive optical communication network or PON, on at least a second termination device located at one end of at least a second branch of said PON.

[0016] Such a method is particular in that it comprises the following steps implemented by a disturbance diagnosis establishment module: transmission to said first termination device of a request to transmit at least one first optical signal, called test signal at a first transmission power; transmission to the second termination device of a request to transmit at least one second optical signal at a second transmission power, called nominal power, obtaining, for said second optical signal, at least one measurement of a value of at least one indicator of reception quality of said second optical signal by a third termination device; establishment of the disturbance diagnosis of said second termination device as a function of said value of at least one indicator of reception quality of said second optical signal measured.

[0017] Such a method for establishing a disturbance diagnosis makes it possible to evaluate the impact of a modification of the transmission power of an optical signal of a termination device belonging to a PON on the other termination devices belonging to the PON, in particular for the purposes of evaluating the possibilities of parametric optimization of the termination devices. Termination device is understood to mean an optoelectronic device comprising means for transmitting an optical signal at a given transmission power and means for receiving an optical signal transmitted by at least one other termination device.

[0018] To this end, a first termination device transmits a first optical test signal at a first transmission power transmitted by the PON. Following the transmission of this optical test signal transmitted by the PON, at least one second termination device transmits a second optical signal at a nominal transmission power transmitted by the PON. A third termination device, having neither transmitted the first optical test signal nor the second optical signal, measures at least one value of at least one reception quality indicator of said second signal making it possible to establish the disturbance diagnosis. In the remainder of this document, the term "measurement" must be interpreted as meaning "estimation" or "determination" of the value of at least one reception quality indicator of said second optical signal.

[0019] The method for establishing a disturbance diagnosis which is the subject of the present invention is implemented for example when a new termination device is introduced into the PON or when a termination device exhibits a malfunction or when a termination device exhibits a communication quality level below a threshold.

[0020] According to one aspect of the method for establishing a disturbance diagnosis, the latter comprises, prior to establishing said disturbance diagnosis, a step of transmitting, to the first termination device and said at least one second termination device, a schedule for transmitting said optical test signal and said at least one second optical signal, said transmission schedule being divided into a succession of transmission windows, a transmission window comprising: a first time interval during which said first termination device is authorized to transmit the optical test signal; at least one second time interval during which said at least one second device is authorized to transmit said second optical signal at the nominal transmission power, a value of the first transmission power of the optical test signal varying from one time window to another.

[0021] The transmission of a transmission schedule makes it possible to wake up the termination devices involved in the test process and thus to save energy. The transmission schedule makes it possible to temporally arbitrate the speaking times imposed on the different termination devices, with a view to good coordination between them for the implementation of the invention.

[0022] Such a transmission schedule proposes a repeated succession of transmission of the test signal by a first termination device followed by the transmission of at least a second optical signal at the nominal power by each of the termination devices concerned by the transmission schedule.

[0023] Each time the test signal is transmitted by said first termination device, the value of the transmission power of the test signal is modified in order to determine which transmission power value generates disturbances on the other termination devices.

[0024] According to another aspect of the method for establishing a disturbance diagnosis, the step of obtaining at least one measurement of a value of at least one reception quality indicator of said second optical signal comprises: a comparison of said value of at least one reception quality indicator of said second optical signal measured with a first threshold; when the value of at least one reception quality indicator of said second optical signal measured is less than or equal to the first threshold, a storage of an identifier of the first termination device, an identifier of the second device and a value of said first transmission power.

[0025] Thus, the module for establishing a disturbance diagnosis can identify, among all the termination devices belonging to the PON, which is the source of disturbance, the value of the transmission power for which this termination device generates disturbances and finally which are negatively impacted by the transmission of the test signal.

[0026] According to one aspect of the method for establishing a disturbance diagnosis, the step of obtaining at least one measurement of the value of at least one reception quality indicator of said second optical signal further comprises: a comparison of said value of at least one reception quality indicator of said second optical signal measured with a second threshold lower than the first threshold; when the value of at least one reception quality indicator of said second optical signal measured is lower than or equal to the second threshold, a storage of an identifier of the first termination device, an identifier of the second device, a value of said first transmission power and information on the off-hook of the second termination device.

[0027] Thus, the module for establishing a disturbance diagnosis can identify, among all the termination devices belonging to the PON which is the source of disturbance, the value of the transmission power for which this termination device generates disturbances and finally which are negatively impacted by the transmission of the test signal to the point of dropping out, that is to say to the point of no longer being functional. According to yet another aspect of the method for establishing a disturbance diagnosis, said at least one indicator of reception quality of said second optical signal belongs to the group comprising: a power level in reception of said second optical signal measured by said third termination device; a bit error rate of said second optical signal estimated by said third termination device.

[0028] Thus, several indicators of reception quality of an optical signal can be envisaged for the implementation of the invention. Typically, for a given termination device, a difference between a measured reception power level and an expected reception power level below a threshold means that the value of the transmission power of the test signal used during the measurement impacts the termination device considered. Similarly, a bit error rate above a threshold means, for example, that the transmission power value of the test signal for the current measurement impacts the termination device considered.

[0029] According to another aspect of the method for establishing a disturbance diagnosis, the PON comprising an optical exchange connected to at least one first line termination device by at least one optical fiber constituting said first branch of said PON and to at least one second line termination device by at least one other optical fiber constituting said second branch of said PON, the first termination device is embedded in the first line termination device, the second termination device is embedded in the second line termination device, and the third termination device is embedded in the optical exchange.

[0030] In this case, the process of establishing a disturbance diagnosis makes it possible to diagnose the impact of the emission of a line termination device located in the premises of an end user on the other line termination devices belonging to the PON.

[0031] According to another aspect of the method for establishing a disturbance diagnosis, the PON comprising an optical exchange connected to at least one first line termination device by at least one optical fiber constituting said first branch of said PON and to at least one second line termination device by at least one other optical fiber constituting said second branch of said PON, the first termination device is embedded in the optical exchange and transmits the optical test signal to the first termination device, the second termination device is also embedded in the optical exchange and transmits the second optical signal to the second termination device, and the third termination device is embedded in the second termination device.

[0032] In this case, the method for establishing a disturbance diagnosis makes it possible to diagnose, for example when the optical exchange is equipped with a dual operating interface, such as an MPM interface (“Multi-PON Module”) allowing the simultaneous use of G-PON and XGS-PON technologies within the same PON, the impact of a termination device conforming to G-PON technology on the termination device conforming to XGS-PON technology.

[0033] The invention also relates to a module for establishing a diagnosis of disturbances generated by at least one first termination device, located at one end of a first branch of a passive optical communication network or PON, on at least one second termination device located at one end of at least one second branch of said PON.Such a disturbance diagnosis establishment module comprises at least one processor configured to: transmit to said first termination device a request for transmission of at least one first optical signal, called test signal at a first transmission power; transmit to the second termination device a request for transmission of at least one second optical signal at a second transmission power, called nominal power, obtain, for said second optical signal, at least one measurement of a value of at least one indicator of reception quality of said second optical signal by a third termination device; establish the disturbance diagnosis of said second termination device as a function of said measured value of at least one indicator of reception quality of said second optical signal.

[0034] According to one aspect of the module for establishing a disturbance diagnosis, the PON comprising an optical exchange connected to at least one first line termination equipment by at least one optical fiber constituting said first branch of said PON and to at least one second line termination equipment by at least one other optical fiber constituting said second branch of said PON, said module for establishing a disturbance diagnosis is embedded in the optical exchange.

[0035] Thus, the disturbance diagnosis module can be a remote server communicating at least with the PON optical exchange or be embedded in the optical exchange.

[0036] In the first case, the diagnosis is established on the basis of measurement information received by the disturbance diagnosis module from the optical exchange, for example. In the second case, the diagnosis is established by the optical exchange itself.

[0037] The invention finally relates to a computer program product comprising program code instructions for implementing a method as described above, when executed by a processor.

[0038] The invention also relates to a computer-readable recording medium on which is recorded a computer program comprising program code instructions for executing the steps of the method according to the invention as described above.

[0039] Such a recording medium may be any entity or device capable of storing the program. For example, the medium may include a storage medium, such as a ROM, for example a CD-ROM or a microelectronic circuit ROM, or a magnetic recording medium, for example a USB flash drive or a hard disk.

[0040] On the other hand, such a recording medium may be a transmissible medium such as an electrical or optical signal, which may be conveyed via an electrical or optical cable, by radio or by other means, so that the computer program contained therein is remotely executable. The program according to the invention may in particular be downloaded over a network, for example the Internet.

[0041] List of figures

[0042] Other aims, characteristics and advantages of the invention will appear more clearly on reading the following description, given as a simple illustrative, and non-limiting, example, in relation to the figures, among which:

[0043] [fig. U: this figure represents a PON type network according to the state of the art, [fig- 2]: this figure represents a PON type network in which the method for establishing a disturbance diagnosis according to the present invention,

[0044] [fig. 3]: this figure represents the steps implemented by the different terminating equipment of the PON network during the execution of the method for establishing a diagnosis of disturbances generated by at least a first terminating device embedded in a first ONU on at least a second terminating device embedded in a second ONU,

[0045] [fig- 4]: this figure represents a first emission schedule,

[0046] [fig- 5]: this figure represents the steps implemented by the various termination equipment constituting the PON network during the execution of the method for establishing a diagnosis of disturbances generated by at least a first termination device embedded in the OLT on the second termination device also embedded in the OLT, knowing that the first termination device complies with G-PON technology and complies with XGS-PON technology, and the second termination device complies with XGS-PON technology,

[0047] [fig- 6]: this figure represents a second emission schedule,

[0048] [fig- 7]: this figure represents a module for establishing a disturbance diagnosis capable of implementing the method for establishing a disturbance diagnosis which is the subject of the present invention.

[0049] Detailed description of embodiments of the invention

[0050] The general principle of the invention is based on the implementation of a test campaign within a PON during which the impact of the emission of a first optical signal called a test signal by a first PON termination device on at least one other PON termination device is evaluated.

[0051] We now present, in relation to [fig. 2] a PON type network 100. The components of this network 100 previously described with reference to figure 1 keep the same references.

[0052] The network 100 comprises an optical line terminal 10 located at the optical exchange (or CO for "Central Office") connected to an optical coupler 30 by a first optical fiber 20, as well as a set of user modules ONU-i, where i G {1, ... , n}. The user modules ONU-i are respectively connected to the coupler 30 by means of a dedicated optical fiber 40-i where i G {1, ... , n]. A branch Bi of the network 100 is made up of the optical fiber 20, coupler 30 and an optical fiber 40- i. Thus, each ONU-i is connected to the OLT 10 by means of a dedicated branch Bi.

[0053] The OLT 10 and the ONU-i are commonly referred to as termination equipment because they are each located at one end of a constituent Bi branch of the 100 network.

[0054] In the example shown in Figure 2, the OLT 10 comprises two termination devices 50-1 and 50-2. A termination device 50-1, 50-2 is an optoelectronic device comprising means for transmitting an optical signal at a given transmission power and wavelength and means for receiving an optical signal transmitted by at least one other termination device.

[0055] It is understood that the OLT 10 may comprise a single termination device 50-1, 50-2 or more than two termination devices 50-1, 50-2. In the remainder of this document, the termination device 50-1 conforms to the G-PON technology and conforms to the XGS-PON technology, and the termination device 50-2 conforms to the XGS-PON technology. Thus, the termination device 50-1 transmits at a first wavelength specific to this technology and the termination device 50-2 transmits at a second wavelength specific to this technology, distinct from the first wavelength.

[0056] In the example shown in Figure 2, an ONU-i comprises a termination device 70-i. A termination device 70-i is an optoelectronic device comprising means for transmitting an optical signal at a given transmission power and wavelength and means for receiving an optical signal transmitted by at least one other termination device.

[0057] It is understood that an ONU-i may include more than one 70-i termination device. In the remainder of this document, the 70-1 termination device embedded in the ONU-1 is compliant with G-PON technology compliant with XGS-PON technology, and the 70-2 termination device embedded in the ONU-2 is compliant with XGS-PON technology. Thus the termination device.

[0058] As already explained with reference to FIG. 1, the termination device 50-1 transmits a downlink optical signal to the ONU-i and each termination device 70-i embedded in an ONU-i transmits an uplink optical signal to the OLT 10 in a time interval specific to it. In order for the OLT 10 to be able to identify the uplink optical signal specific to each ONU-i, a transmission schedule is previously imposed on each ONU-i.

[0059] Finally, in the example shown in Figure 2, the OLT 10 includes a module 60 for establishing a disturbance diagnosis, the function of which will be better understood upon reading the remainder of this document. In other implementations of the present invention, the module 60 for establishing a disturbance diagnosis may be located in a remote server with which the OLT can communicate in order to exchange data relating to establishing a disturbance diagnosis.

[0060] [Fig. 3] represents the steps implemented by the different termination equipment 10, ONU-i constituting the network 100 during the execution of the method for establishing a diagnosis of disturbances generated by at least one first termination device 70-1 embedded in the ONU-1 on at least one second termination device 70-i embedded in an ONU-i with i different from 1.

[0061] In a first step E1, the module for establishing a disturbance diagnosis 60 transmits, in a message MSG1 to the OLT 10 and the ONU-i, a transmission schedule CalUp relating to a test campaign to be carried out within the network 100 for the upstream communication direction, that is to say for optical signals transmitted by the different ONU-i to the OLT 10.

[0062] Such a CalUp transmission schedule is represented with reference to [FIG. 4]. Such a CalUp transmission schedule comprises a plurality of transmission windows Wj, j G {1, ... , m}. Each transmission window Wj is itself divided into a plurality of time slots TSi, i G {1, ... , n}. For each transmission window Wj, the first time slot TSI is granted to the termination device 70-1 which is the subject of the test campaign, the other time slots TSi, with i different from 1, are allocated to the other ONU-i, for example, the time slot TS2 is allocated to the ONU-2, the time slot TS3 is allocated to the ONU-3, etc.

[0063] For each first time interval TSI of each time window Wj, the message MSG1 comprises an indication of a value of an optical transmission power EOPT that the termination device 70-1 must use when transmitting the test signal TS, the value of this transmission power EOPT of the optical test signal TS varying from one time window to another.

[0064] Upon receipt of the MSG1 message, the ONU-i wait for the start time of the TSi time slot allocated to them in the first transmission window W1 in order to transmit an optical signal to the OLT 10.

[0065] Thus, in a step E2, the termination device 70-1 transmits the optical test signal TS at a first optical transmission power value EOPT1 to the OLT 10.

[0066] In a step E3, the termination device 50-1 embedded in the OLT 10 receives the test signal TS.

[0067] In accordance with the CalUp transmission schedule, at the start time of the TS2 time slot, the termination device 70-2 embedded in the ONU-2 transmits, during a step E4, an optical signal SO at the nominal transmission power to the OLT 10.

[0068] In a step E5, upon receipt of the optical signal SO, the OLT 10 measures a value of a reception quality indicator IQR of the optical signal SO received by the termination device 50-1. Such a reception quality indicator IQR of the received optical signal SO may be a reception power level of the optical signal SO measured by the termination device 50-1 or a bit error rate of the optical signal SO estimated by the termination device 50-1.

[0069] In a step E6, the OLT 10 compares the value of the reception quality indicator IQR of the received optical signal SO with a first threshold SI.

[0070] When the value of the reception quality indicator IQR of the received optical signal SO is less than or equal to the threshold SI, the OLT 10 transmits, in a step E7, a message MSG2 comprising an identifier of the termination device 70-1, an identifier of the device 70-2 and the first optical transmission power value EOPT1 to the module for establishing a disturbance diagnosis 60.

[0071] In a step E8, the OLT 10 also compares the value of the reception quality indicator IQR of the received optical signal SO with a second threshold S2 lower than the first threshold SI.

[0072] When the value of the reception quality indicator IQR of the received optical signal SO is less than or equal to the threshold S2, the OLT 10 transmits, in a step E9, a message MSG3 comprising an identifier of the termination device 70-1, an identifier of the device 70-2 and the first optical transmission power value EOPT1 as well as an item of off-hook information IDec of the termination device 70-2 to the module for establishing a disturbance diagnosis 60.

[0073] Steps E2 to E9 are repeated for each time interval TSi of a time window Wj, therefore for all the ONU-Is receiving the CalUp transmission schedule, and for all the m Wj windows included in the CalUp transmission schedule.

[0074] Once all the measurements of the test campaign have been carried out, the disturbance diagnosis establishment module 60 is in possession of all the data necessary for establishing a diagnosis of the disturbances generated by the termination device 70-1 on the termination devices 70-i, with I different from 1, as a function of the values ​​of at least one reception quality indicator IQR obtained for each of the termination devices 70-i as well as, where appropriate, the data included in the messages MGS2 and MSG3.

[0075] Thus, in a step E10, the module for establishing the disturbance diagnosis 60 establishes a diagnosis of disturbances generated by the termination device 70-1 on the different termination devices 70-i, with i different from 1. [Fig. 5] represents the steps implemented by the different termination equipment 10, ONU-i constituting the network 100 during the execution of the method for establishing a diagnosis of disturbances generated by at least a first termination device 50-1 embedded in the OLT 10 on the second termination device 50-2 also embedded in the OLT 10 knowing that the termination device 50-1 complies with the G-PON technology and complies with the XGS-PON technology, and the termination device 50-2 complies with the XGS-PON technology.

[0076] In a first step Gl, the module for establishing a disturbance diagnosis 60 transmits, in a message MSG1' to the OLT 10 and the ONU-i, a transmission schedule CalDw relating to a test campaign to be carried out within the network 100 for the downlink communication direction, that is to say for optical signals transmitted by the different termination devices 50-1 and 50-2 to the different ONU-i.

[0077] Such a transmission schedule CalDw is represented with reference to [FIG. 6], Such a transmission schedule CalDw comprises a plurality of transmission windows Wj, j £ {1, Each transmission window Wj is itself divided into two time intervals TS1 and TS2. For each transmission window Wj, the first time interval TS1 is granted to the termination device 50-1 which is the subject of the test campaign, and the second time interval TS2, to the termination device 50-2.

[0078] For each first time interval TS1 of each time window Wj, the message MSG1' comprises an indication of a value of an optical transmission power EOPT that the termination device 50-1 must use when transmitting the test signal TS, the value of this transmission power EOPT of the optical test signal TS varying from one time window to another.

[0079] Upon receipt of the MSG1' message, the termination devices 50-1 and 50-2 wait for the start time of the time slot TS1 or TS2 allocated to them in the first transmission window W1 in order to transmit an optical signal to the ONU-i.

[0080] Thus, in a step G2, the termination device 50-1 transmits the optical test signal TS at a first optical transmission power value EOPT1 through the network 100.

[0081] In accordance with the transmission schedule CalDw, at the start time of the time interval TS2, the termination device 50-2 transmits, during a step G3, an optical signal 50 at the nominal transmission power to the ONU-2 which is the only one, in the example described, to have a termination device 70_2 capable of implementing the XGS-PON and therefore capable of receiving and carrying out measurements on the signal SO.

[0082] In a step G4, upon receipt of the optical signal SO, the ONU-2 measures a value of a reception quality indicator IQR of the optical signal SO received by the termination device 70-2. Such a reception quality indicator IQR of the received optical signal SO may be a reception power level of the optical signal SO measured by the termination device 70-2 or a bit error rate of the optical signal SO estimated by the termination device 70-2.

[0083] In a step G5, the ONU-2 compares the value of the reception quality indicator IQR of the received optical signal SO with a first threshold SI.

[0084] When the value of the reception quality indicator IQR of the received optical signal SO is less than or equal to the threshold SI, the ONU-2 transmits, in a step G6, a message MSG2' comprising an identifier of the termination device 50-1, an identifier of the device 50-2 and the first optical transmission power value EOPT1 to the module for establishing a disturbance diagnosis 60 either directly or via the OLT 10 which then serves as a relay. In a step G7, the ONU-2 also compares the value of the reception quality indicator IQ.R of the received optical signal SO with a second threshold S2 lower than the first threshold SI.

[0085] When the value of the reception quality indicator IQR of the received optical signal SO is less than or equal to the threshold S2, the ONU-2 transmits, in a step G8, a message MSG3' comprising an identifier of the termination device 50-1, an identifier of the device 50-2 and the first optical transmission power value EOPT1 as well as an item of off-hook information IDec of the termination device 50-2 to the module for establishing a disturbance diagnosis 60 either directly or via the OLT 10 which then serves as a relay.

[0086] Steps G2 to G8 are repeated for all m windows Wj that make up the emission schedule CalDw.

[0087] Once all the measurements of the test campaign have been carried out, the disturbance diagnosis establishment module 60 is in possession of all the data necessary for establishing a diagnosis of the disturbances generated by the termination device 50-1 on the termination device 50-2 based on the values ​​of at least one reception quality indicator IQ.R obtained for the termination device 50-2 as well as, where applicable, the data included in the messages MGS2' and MSG3'.

[0088] Thus, in a step G9, the disturbance diagnosis establishment module 60 establishes a diagnosis of disturbances generated by the termination device 50-1 on the termination device 50-2.

[0089] [Fig. 7] represents a module for establishing a disturbance diagnosis 60 capable of implementing the method for establishing a disturbance diagnosis which is the subject of the present invention.

[0090] A disturbance diagnosis establishment module 60 may comprise at least one hardware processor 700, a storage unit 701, a first interface 702, and at least one second interface 703 which are connected to each other through a bus 704. Of course, the constituent elements of the disturbance diagnosis establishment module 60 may be connected by means of a connection other than a bus. In an exemplary embodiment, the disturbance diagnosis establishment module 60 is embedded in the OLT 10.

[0091] The processor 700 controls the operations of the troubleshooting module 60. The storage unit 701 stores at least one program for implementing the method of the invention to be executed by the processor 700, and various data, such as parameters used for calculations performed by the processor 700, intermediate data of calculations performed by the processor 700, etc. The processor 700 may be formed by any known and suitable hardware or software, or by a combination of hardware and software. For example, the processor 700 may be formed by dedicated hardware such as a processing circuit, or by a programmable processing unit such as a central processing unit (Central Processing Unit) which executes a program stored in a memory thereof.

[0092] The storage unit 701 may be formed by any suitable means capable of storing the program(s) and data in a computer-readable manner. Examples of the storage unit 701 include non-transitory computer-readable storage media such as semiconductor memory devices, and magnetic, optical, or magneto-optical recording media loaded into a read and write unit. The first interface 702 provides an interface between the troubleshooting module 60 and at least one termination device 50-1, 50-2 embedded in the OLT 10.

[0093] The second network interface 703 provides a connection between the troubleshooting module 60 and the ONU-i.

Claims

CLAIMS 1. Method for establishing a diagnosis of disturbances generated by at least one first terminating device (50-1, 50-2, 70-i), located at one end of a first branch (20, 40-i) of a passive optical communication network or PON, on at least one second terminating device (50-1, 50-2, 70-i) located at one end of at least one second branch (20, 40-i) of said PON, said method comprising the following steps implemented by a disturbance diagnosis establishing module (60): transmitting to said at least one first terminating device (50-1, 50-2, 70-i) a request to transmit at least one first optical signal (TS), called test signal at a first transmission power (EOPT1, EOPT2);transmitting to said at least one second termination device (50-1, 50-2, 70-i) a request to transmit at least one second optical signal (SO) at a second transmission power, called nominal power, obtaining, for said second optical signal (SO), at least one measurement of a value of at least one reception quality indicator (IQR) of said second optical signal by a third termination device (50-1, 50-2, 70-i); establishing the disturbance diagnosis of said at least one second termination device (10, 50-1, 50-2, 70-i) as a function of said measured value of at least one reception quality indicator (IQR) of said second optical signal.; 2. Method for establishing a disturbance diagnosis according to claim 1, comprising, prior to establishing said disturbance diagnosis, a step of transmitting, to said at least one first termination device (50-1, 50-2, 70-i) and said at least one second termination device (50-1, 50-2, 70-i) a transmission schedule for said optical test signal and said at least one second optical signal, said transmission schedule (Calup, Caldw) being divided into a succession of transmission windows (Wi), a transmission window comprising: a first time interval (TS n ) during which said first termination device is authorized to transmit said optical test signal (TS); at least a second time interval (TS n) during which said at least one second device is authorized to transmit said second optical signal (SO) at the nominal transmission power, a value of the first transmission power of said optical test signal varying from one time window to another.

3. Method for establishing a disturbance diagnosis according to claim 1 or claim 2 wherein the step of obtaining at least one measurement of a value of at least one reception quality indicator (IQR) of said second optical signal comprises: a comparison of said value of at least one reception quality indicator of said second optical signal (SO) measured with a first threshold; when the value of at least one reception quality indicator (IQR) of said second optical signal measured is less than or equal to the first threshold, a storage of an identifier of the first termination device, an identifier of the second termination device and a value of said first transmission power (EOPT1, EOPT2).

4. Method for establishing a disturbance diagnosis according to claim 3 in which the step of obtaining at least one measurement of the value of at least one quality indicator (IQR) of reception of said second optical signal further comprises: a comparison of said value of at least one reception quality indicator of said second measured optical signal with a second threshold lower than the first threshold; when the value of at least one reception quality indicator (IQR) of said second measured optical signal is lower than or equal to the second threshold, a storage of an identifier of the first termination device (50-1, 50-2, 70-i), of an identifier of the second termination device (50-1, 50-2, 70-i), of a value of said first transmission power (EOPT1, EOPT2) and of off-hook information of the second termination device.

5. Method for establishing a disturbance diagnosis according to any one of the preceding claims, in which said at least one reception quality indicator of said second optical signal belongs to the group comprising: a reception power level of said second optical signal measured by said third termination device (50-1, 50-2, 70-i); a bit error rate of said second optical signal estimated by said third termination device (50-1, 50-2, 70-i).

6. Method for establishing a disturbance diagnosis according to any one of the preceding claims wherein, the PON comprising an optical exchange connected to at least one first line termination equipment (10) by at least one optical fiber (20, 40-i) constituting said first branch of said PON and to at least one second line termination equipment) by at least one other optical fiber (20, 0-i) constituting said at least one second branch of said PON, said at least one first termination device (50-1, 50-2, 70-i) is embedded in the first line termination equipment, said at least one second termination device (50-1, 50-2, 70-i) is embedded in the second line termination equipment, and the third termination device is embedded in the optical exchange.

7. Method for establishing a disturbance diagnosis according to any one of claims 1 to 5 wherein, the PON comprising an optical exchange (10) connected to at least one first line termination equipment (50-1, 50-2, 70-i) by at least one optical fiber (20, 40-i) constituting said first branch of said PON and to at least one second line termination equipment by at least one other optical fiber (20, 40-i) constituting said second branch of said PON, the at least one first termination device (50-1, 50-2) is embedded in the optical exchange (10) and transmits said test signal to said at least one first termination equipment, said at least one second termination device (50-1, 50-2) is also embedded in the optical exchange and transmits said at least one second optical signal to said at least one second termination equipment,and the third termination device is embedded in the second termination equipment., 8. Module for establishing (60) a diagnosis of disturbances generated by at least one first terminating device (50-1, 50-2, 70-i), located at one end of a first branch (20, 40-i) of a passive optical communication network or PON, on at least one second terminating device (50-1, 50-2, 70-i) located at one end of at least one second branch (20, 40-i) of said PON, said disturbance diagnosis establishing module comprising at least one processor configured to: transmit to said at least one first terminating device a request for transmission of at least one first optical signal, called test signal at a first transmission power; transmit to said at least one second terminating device a request for transmission of at least one second optical signal at a second transmission power, called nominal power, obtain, for said second optical signal, at least one measurement of a value of at least one indicator of reception quality of said second optical signal by a third termination device; establishing the diagnosis of disturbance of said at least one second termination device as a function of said value of at least one indicator of reception quality of said measured second optical signal.

9. Module for establishing (60) a disturbance diagnosis according to claim 8 characterized in that the PON comprises an optical exchange (10) connected to at least one first line termination equipment (50-1, 50-2) by at least one optical fiber (20, 40-i) constituting said first branch of said PON and to at least one second line termination equipment by at least one other optical fiber (20, 40-i) constituting said second branch of said PON, said module for establishing a disturbance diagnosis is embedded in the optical exchange (10).

10. Computer program product downloadable from a communications network and / or stored on a computer-readable medium and / or executable by a microprocessor, characterized in that it comprises program code instructions for executing a method according to any one of claims 1 to 7 when executed by a computer.

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