WO2002102089A1

WO2002102089A1 - System for supervision of digital equipment and input and output signals thereof

Info

Publication number: WO2002102089A1
Application number: PCT/FR2002/001525
Authority: WO
Inventors: Christian Gerard; Alain Souquet; Joël Conchis
Original assignee: France Telecom
Priority date: 2001-06-08
Filing date: 2002-05-02
Publication date: 2002-12-19
Also published as: FR2825878B1; FR2825878A1

Abstract

The invention concerns a system form monitoring the incoming (SE) and outgoing (SS) signals of a set of equipment items (E1-EQ), such as a digital television transmitter, and the equipment items themselves to detect various faults therein. In response to one of the detected operating faults (MFE) in an equipment (Eq), an equipment alarm (AE) signals the breakdown of the equipment, and a service alarm (AS) is directly generated if it determines with sufficient certainty the impact of the detected fault on the outgoing signal, or in correlation with alarms resulting from detected faults in the outgoing signals if the impact of the detected fault on the outgoing signal is defined with uncertainty. Additionally, the system prevents cascading alarms resulting from a detected fault and coming from detectors downstream of the location where the fault has been detected.

Description

SYSTEM FOR MONITORING DIGITAL EQUIPMENT AND ITS INPUT AND OUTPUT SIGNALS

The present invention relates to the supervision of digital signals and digital equipment in order to generate alarms reflecting in particular operational faults in the equipment and quality faults in the signal leaving all the equipment.

In particular, the invention relates to the supervision of a platform for generating digital signals, in particular for digital television, digital radio or the broadcasting of data by a network of IP (Internet Protocol) type. For example, the invention makes it possible to supervise a digital television transmitter transmitting a composite multiplex signal outgoing in clear or scrambled format, supporting several audiovisual programs to be broadcast through a satellite.

Currently, MPEG-2 standard flow analyzers measure many predetermined parameters in the flow of transport packets leaving the digital television transmitter. Such an analyzer is thus limited to the analysis of signaling according to the MPEG-2 standard, while there is a need to monitor operating faults in the equipment of the transmitter which can cause quality faults in the signal. coming out of the transmitter.

The present invention thus aims to provide a supervision system which supervises both operating faults in equipment and quality faults in the signal leaving all the equipment, and preferably also in signals entering all the equipment, while synthesizing the alarms resulting from the detected faults so that an operator exploiting the alarms is not invaded by too many d alarms.

To achieve this objective, a system for monitoring at least one item of equipment and a digital signal leaving the item of equipment, comprising downstream detection means for detecting quality faults in the outgoing signal, and an equipment fault detector for detecting operating faults relating to the equipment, is characterized in that it comprises a first fault filtering means generating equipment alarms each in response to one detected of respective operating faults of the equipment, a second fault filtering means generating downstream service alarms each in response to a detected one of respective quality faults in the outgoing signal, a first decision means generating a self-sufficient service alarm and inhibiting any downstream service alarm generated by the second filtering means as long as the detected equipment fault persists when the impact of the equipment fault t detected is defined with certainty on the outgoing signal, and a second decision means generating a service alarm dependent on any downstream service alarm generated by the second filtering means as long as the detected equipment fault persists when the impact of the Equipment fault detected is defined with uncertainty on the outgoing signal. The invention also relates to a supervision device included in the system for supervising according to the invention, including the filtering means and the decision means set out above and cooperating with the fault detectors which transmit respective fault messages to it.

Thanks to the filtering and correlation means, only the service alarm which corresponds to a fault detected the most upstream in relation to a faulty equipment, or as will be seen hereinafter in relation to a faulty set of equipment. , is only signaled so that the operator is not invaded by other alarms resulting from faults detected further downstream. More generally, the supervision system of the invention can comprise several pieces of equipment and at least the signal leaving all the pieces of equipment. The system then comprises equipment fault detectors for detecting operating faults respectively relating to the equipment. In the supervision device, the first fault filtering means generates equipment alarms relating respectively to sets of respective operating malfunctions of the equipment, and the first decision means also inhibits all the service alarms resulting from faulty operations. equipment relating to equipment located downstream of the equipment in which the equipment fault corresponding to the generated self-sufficient service alarm has been detected.

More completely, the supervision system comprises at least one upstream detector for detecting quality faults in an incoming signal from the equipment or from several equipment. The supervision device then comprises a third fault filtering means generating upstream service alarms each in response to a detected one of respective quality faults in the incoming signal, and a third decision means inhibiting any equipment alarm generated by the first fault filtering means , any self-sufficient service alarm generated by the first decision means, any dependent service alarm generated by the second decision means and any downstream service alarm generated by the second fault filtering as long as a quality fault detected by the upstream detector persists. In general, the system includes as many upstream quality fault detectors as there are components or multiplex signals in the incoming signal to detect quality faults in the components or multiplex signals respectively.

According to a preferred embodiment described in detail below, the supervision system supervises several pieces of equipment in a digital television transmitter.

Other characteristics and advantages of the present invention will appear more clearly on reading the following description of several preferred embodiments of the invention with reference to the corresponding appended drawings in which:

- Figure 1 is a schematic block diagram of a supervision system according to the invention; - Figure 2 is a fault message processing algorithm, and alarm generation implemented in a system supervision device; Figure 3 is a block diagram of a supervised digital television signal transmitter according to the invention; and FIG. 4 is similar to FIG. 1 and relating to a supervision system for the transmitter of FIG. 3.

A signal and digital equipment supervision system SUP according to the invention is intended to supervise at least at least one telecommunications equipment, at least one signal leaving this equipment and preferably at least one signal entering this equipment. More generally, as illustrated in FIG. 1, the SUP system supervises several pieces of equipment El, ... Eq, ... EQ for example arranged in cascade, a signal SE entering all the pieces of equipment El to EQ and a signal SS leaving all the equipment El to EQ.

All of the equipment E1 to EQ is included in a digital telecommunications network RT, or in a set of telecommunications networks. A network can be a telephone or radiotelephone network, or a broadband network for example a network for broadcasting digital television signals DVB (Digital Video Broadcasting), a network for broadcasting digital radio signals DAB (Digital Radio Broadcasting), a packet transmission network, the internet network, an intranet network, a local network, or any terrestrial or satellite network, etc. As detailed below, all of the equipment E1 to EQ can constitute, for example, a transmitter of a telecommunications link LT to the network RT, or a receiver at the other end of this link.

The incoming signal SE may consist of a single signal, or of several component signals, called components, which may be of different natures and which are multiplexed. digitally in the single signal, as the video and audio components in a digital television signal, or as composite signals of several multiplex television programs, or may consist of several composite signals and / or components in parallel. The outgoing signal SS is generally of the same nature as the incoming signal SE and can result, for example, from the multiplexing of several incoming signals processed by the equipment. An item of equipment to be monitored El to EQ can be, for example, a digital interface, an encoder, a scrambler, a multiplexer, a switch, or an item of equipment whose function is reciprocal from that of one of the preceding items of equipment or a set of such items of equipment. .

The supervision system SUP includes three fault detector batteries DM1 to DMI, DE1 to DEQ and DV1 to DVJ for detecting quality faults in the incoming signal SE, operating faults in the equipment El to EQ, and faults of quality in the outgoing signal SS, and a supervision device DS for processing fault messages produced by the detectors in order to generate alarms.

The first fault detectors DMI to DMI, where I is an integer greater than or equal to 1, detect various quality faults in the incoming signal SE, such as an absence or an insufficient level of the incoming signal SE or of a component or of a multiplex signal in the incoming signal, a lack of synchronization of the incoming signal or of one of its components with a local clock, insufficient flow of the incoming signal or of a component or of a multiplex signal of that here, or even defects depending on the nature of the data supported by the incoming signal, such as image quality defects in a video signal or in one of its components or acoustic quality defects in a sound signal or in one of its components. Each upstream detector DMi, with 1 <i <I, is connected to the input of all the equipment El to EQ, in this case to the input of the first equipment El, in order to analyze the incoming signal SE in based on predetermined criteria. Each fault detector DMi detects one or more respective quality faults in the incoming signal SE in order to produce one or more respective fault messages MFM transmitted to an upstream fault filter FM in the device DS. The supervision system SUP can comprise as many upstream quality fault detectors DVM, DAM (FIG. 4) as there are components or multiplex signals in the incoming signal SE to detect respectively quality faults in the components or in the multiplex signals.

The third battery of detectors is constituted by downstream quality fault detectors DV1 to DVJ, where J is an integer greater than or equal to 1. Each downstream detector DVj, with 1 <j <J, detects one or more respective quality faults in the outgoing signal SS in order to produce one or more respective fault messages MFV transmitted to a downstream fault filter FV in the device DS. The quality faults detected by the downstream detectors in the outgoing signal SS can be similar to those detected by the upstream detectors DMI to DMI in the incoming signal SE, and can be linked for some of them to the components or multiplexed signals in the outgoing signal. So the system SUP can comprise as many downstream quality defect detectors DVA, DAA (FIG. 4) as there are components or multiplex signals in the outgoing signal SS to detect respectively quality faults in the components or in the multiplex signals. A detector fault ^downstream dvj can detect at least one of the following drawbacks: absence or inadequate level of the output signal SS or a component or a multiplex signal in the outgoing signal, no synchronization of the output signal or of one of its components with a local clock, insufficient flow of the outgoing signal or of a component of the outgoing signal. Downstream quality defects may depend on the nature of the data supported by the outgoing signal SS, such as for example inconsistencies in the signal SS or syntax defects in signaling tables transmitted in a digital television signal, or else errors in access parameters transmitted in the outgoing signal due to errors in managing access conditions to all or part of the outgoing signal.

The second battery of fault detectors are detectors DE1 to DEQ which detect operating faults in the equipment El to EQ respectively. In FIG. 1, it has been assumed that each item of equipment Eq, with 1 <q <Q, is associated with a malfunction detector DEq, although in practice, all the items of equipment are not associated with a fault detector; a device can be associated with several malfunction detectors, and a malfunction detector can be associated with several devices. A DEq detector relating to a given piece of equipment treats at least one of the faults following equipment: loss or non-compliance of a data signal entering or leaving the determined equipment or of a clock signal entering the determined equipment, a communication failure between the determined equipment and other equipment, loss or nonconformity of a multiplex signal or of a component of the signal entering or leaving the determined equipment, a bad configuration or a malfunction of the determined equipment, or even a failure or a malfunction of one of the circuits included in 1 'determined equipment or a power supply failure of the determined equipment, ^absence' clock input of the determined equipment or inside thereof, an overshoot of the incoming signal or a component thereof relative to a minimum threshold or a maximum threshold. Like each upstream fault detector DMi and downstream DVj, each malfunction detector DEq detects one or more respective operating faults in one or more respective devices to produce one or more fault messages MFE to an equipment fault filter FE in the DS device. In practice, each fault detector DMi, DEq, DVj includes a software agent according to the SNMP network administration protocol (Simple Network Management Protocol) so that the supervision device DS constituting the heart of the supervision system SUP manages the various detectors by being able to add, modify or delete certain parameters in these detectors and periodically interrogate the detectors so that they transmit their MFM, MFE, MFV fault messages of the "SNMP trap" message type. The supervision device DS comprises, in the form of software modules, the fault message filters FM, FE and FV as well as decision means brought together in an alarm correlator COR. The DS device is for example constituted as a workstation with an alarm display console C and can be relatively distant from the fault detectors and connected to these by its own signaling network. Each SNMP trap error message is encapsulated in a packet of the User Datagram Protocol / Internet Protocol (UDP / IP) transport protocol.

Each of the three fault filters FM, FE and FV filters the respective fault messages MFM, MFE, MFV according to respective filtering rules so as to produce upstream ASM service alarms, AE equipment alarms and possibly alarms respectively. of ASE equipment service, and ASV downstream service alarms. An alarm called "service alarm" translated in the form of a description of alphanumeric characters to be displayed in the console C an effect on the transmission service, that is to say an effect on the outgoing signal SS and / or the if necessary on the incoming signal SE, or on at least one of the components of the outgoing signal, caused by a fault detected upstream, or detected in one of the devices, or detected downstream. An equipment alarm AE translates in the form of an alphanumeric character label to be displayed in the console C an MFE fault message transmitted by one of the operating fault detectors DE1 to DEQ.

Each filtering rule can apply one or more conditions to a single respective fault message, or to a group of messages relating to respective faults which have the same or similar impact on the quality of the outgoing signal, or of a component or characteristic of the outgoing signal, so that the filter applying this filtering rule produces a respective alarm in response to at least one of the group's fault messages.

Thus the FM filter produces some ASM alarms according to respective labels to be displayed in the console C each in response to a respective fault message or to one of several respective fault messages MFM corresponding to faults detected in the incoming signal SE having the same impact on the quality of the outgoing signal SS. For example, one of the faults corresponding to a lack of component or synchronization in the incoming signal generates the generation of an ASM service alarm by the upstream filter FM to the correlator COR to indicate the loss of a component of the signal SE entering all the equipment El to EQ. Similarly, the filtering rules applied in the downstream filter FV are applied to sets of fault messages MFV corresponding respectively to downstream service alarms ASV which each indicate a respective impact on the quality of the service rendered in response to a message of respective fault or to one of the messages relating to respective quality faults detected in the outgoing signal SS. For example, faults such as hissing, buzzing, saturation and right / left phase shift of a stereophonic audio component in the outgoing signal SS generates the generation of an ASV service alarm by the FV filter towards the COR correlator to indicate a bad quality of the audio component in the outgoing signal SS. Alternatively, some of the fault detectors DMI to DMI, DV1 to DVJ operate in automatic mode to continuously scan the respective signal SE, SS, and others of these fault detectors are activated manually from the DS device in order to carry out a punctual analysis relative to predetermined faults of the respective signal SE, SS.

In the central filter FE, each equipment alarm AE results from at least one malfunction message MFE, and very often results from one of several predetermined fault messages MFE. AE alarm equipment and gathers under one label alphanumeric characters to display in the console C a set of technical malfunctions that have a common origin on a ^'fixed equipment such as a failure of specific equipment or a circuit therein, or an absence or nonconformity of a multiplex signal or of a data signal component or of a clock signal as input from or internal to the determined equipment. The AE equipment alarms constitute a first level of supervision of all the equipment. A second level of supervision is carried out by the FE filter and the COR correlator. The second level of supervision defines filtering rules to generate an ASE service alarm to be displayed in the supervision console C which depends in particular on the alarm of equipment AE and of the type of equipment El to EQ at the origin of the AE alarm.

An AS service alarm results from the application of a self-sufficient filtering rule or a dependent filtering rule. As will be seen in more detail below, a self-sufficient rule determines with certainty the impact of an equipment malfunction signaled by an AE alarm on the service rendered, i.e. the consequence of the fault on the outgoing signal SS or more precisely, if necessary, on a so-called analog signal such as a multiplex signal in the outgoing signal, or a component in the outgoing signal or in the multiplex signal. The correspondence between the technical malfunction in an equipment and the impact on the SS signal or the like is ensured by TM modeling tables included in the FE filter. As will be seen in certain examples below, an ASE service alarm resulting from a self-sufficient rule may be "nil", that is to say confused with the corresponding equipment alarm AE, or may be selected among two service alarms depending on whether the outgoing signal SS or an analog signal which is liable to suffer the detected fault is being broadcast in the link LT.

A rule is dependent when it determines with uncertainty the impact of the equipment malfunction signaled by an AE alarm on the quality of the service provided, i.e. on the quality of the outgoing signal SS or an analogous signal. . In this case, the COR correlator decides additional analyzes in order to remove any uncertainty about the impact caused to the SS service, by correlating one or more ASV downstream service alarms produced by the FV filter in response to relative MFV downstream fault messages. quality faults which are detected by one or more downstream detectors DV1 to DVJ at the same time as the operating fault causing the AE alarm is detected. FIG. 2 summarizes in the form of an algorithm for processing the MFM, MFE, MFV fault messages in the supervision device DS according to the invention in order to generate at least one alarm.

Initially, in a step E0, a current fault detector DC, which can be one of the detectors DMI to DMI, DE1 to DEQ and DV1 to DVJ detects a fault signaled by a fault message MF, which can be a message MFM , MFE or MFV. The fault is suffered, directly or indirectly through one of the equipment to be supervised El to EQ, by a current signal S which may in particular be an incoming signal SE or outgoing SS or a signal similar to the latter relating to one of the equipment. Then in one of the conditional steps E1, E2 and E3, the supervision device DS identifies the message MF transmitted by the current detector DC as an upstream fault message MFM, or as an equipment fault message MFE, or as an MFV downstream fault message, in order to apply the respective filtering and correlation rules defined above.

When the current fault message MF is an upstream quality fault message MFM produced by a current detector DMi, the device DS essentially performs three steps Eli, E12 and E13. Step E1 filters the message MFM in the FM filter in order to produce in step E12 an ASM alarm which is applied to the correlator COR. In order to prevent the personnel using the SUP supervision system from being overwhelmed by a flood of alarms displayed on the console C, the correlator COR inhibits in step E13 any alarm AE, ASE, ASV which results from any fault message MFE, MFV produced by any fault detector located downstream of the current fault detector DMi as long as the MFM fault message persists. Finally in a final step EF, the correlator COR communicates in alphanumeric form the alarm ASM to the supervision console C to display it. In a manner analogous to steps Eli to E13, the supervision device DS proceeds to three steps E31 to E33 when the current fault message MF is identified by the device DS as a downstream fault message MFV produced by a current detector DVj to step E3. Step E31 filters the message MFV in the filter FV in order to produce in step E32 an ASV alarm which is communicated by the correlator COR in alphanumeric form to the supervision console C in order to display it in the final step EF . In step E33, the correlator COR inhibits any alarm which may result from any fault message MFV relating to the signal S and produced by one of the downstream fault detectors DV (j + l) to DVJ located downstream of the current detector DVj as long as the MFV fault message persists.

As shown in the center of Figure 2, the fault message processing and alarm generation algorithm is divided into two branches corresponding respectively to self-sufficient and dependent filtering rules when the current fault message MF is a message of malfunction of MFE equipment produced by a current detector DEq in step E2. After the FE filter has filtered the current message MFE in step E21 so as to produce an equipment alarm AE and possibly an ASE service alarm in step E22, the FE filter reads the modeling tables TM so to know the self-sufficient type or dependent on the rule to be applied to the detected operating fault and thus to the alarm of equipment AE produced by the filter FE in step E22. A service alarm AS is then displayed in the console C naturally only if the faulty equipment is actually being processed from a useful signal to the signal SS.

In the next step E24, if the ASE alarm is of the self-sufficient type, this service alarm can be constituted by the equipment alarm AE itself or by an alarm deduced from the AE alarm in a modeling table , the COR correlator transmits the ASE alarm to the supervision console C, as indicated in steps E25 and EF. As in steps E13 and E33, this first central branch of the algorithm succeeding step E2 also includes a step E26 so that the correlator COR inhibits all the alarms of equipment AE and of service ASE, ASV which are generated for the current signal S having undergone the detected fault and which result from any fault message MFE, MFV produced by any equipment malfunction detector DE (q + l) to DEQ or of downstream quality DV1 to DVJ located downstream of the detector DEq current operating fault in which the operating fault corresponding to the self-sufficient alarm was detected, as long as the fault of current equipment processed MFE message persists.

Thus, any other ASE or ASV alarm produced by the FE or FV filter is not displayed by the console C.

For example, when the equipment in which the current fault MFE is at the origin of the self-sufficient alarm ASE is a multiplexer having suffered one of three faults relating to a power supply failure, to a lack of clock output, or if there is no internal clock, indicated by the current fault message MFE, the FE filter produces an AE equipment alarm which signals that the multiplexer has failed. In response to this equipment alarm, the FE filter communicates to the COR correlator the self-sufficient character of the filtering rule to be applied, that is to say the COR correlator notes that the AE alarm corresponds to a single service alarm. ASE which is the direct and unequivocal consequence of the equipment alarm, in this case the absence of the outgoing signal SS at the output of all the equipment El to EQ insofar as the outgoing signal SS could be broadcast in the LT link. The AS service alarm displayed by console C is then constituted by the ASE alarm. During the entire duration of one of the three aforementioned faults signaled in the current message MFE to the filter FE, the correlator COR transmits in step E26 the self-sufficient nature of the alarm ASE on the fault detectors located downstream of the location. in all the equipment where the DC current fault was detected in order to inhibit any other corresponding alarm AE, ASE, ASV produced by the filter FE, FV.

This contextual filtering of cascading alarms originating from faults detected downstream of the place where the treated fault has been detected is preferably increased by a time delay in order to take into account "the propagation time and fault treatment" in detectors and filters capable of treating these faults downstream. According to the previous example, if one of the downstream detectors DV1 to DVJ monitors the presence of a component in the signal SS, this downstream detector generates the generation of an ASV service alarm through the FV filter since the outgoing signal SS himself is absent, and by consequently, the correlator COR inhibits the corresponding alarm ASV.

Returning to steps E23 and E24, if the correlator COR finds that the equipment alarm AE, or that the equipment alarms AE and service ASE transmitted by the filter FE correspond to a service alarm of dependent type in the modeling tables TM, the correlator performs steps E27, E28 and E29 followed by the display step EF. Still according to the previous example, if the faulty equipment is a multiplexer for which the current malfunction detector has signaled in the current message MFE an overflow of one of the components of a signal entering the multiplexer at FE filter in relation to a minimum or maximum flow threshold, the FE filter produces an AE equipment alarm signaling that the flow limit has been exceeded at the output of the multiplexer. The first level of alarm in the FE filter only allows to know that the multiplexer risks generating an erroneous flow distribution in the outgoing signal, but it is not possible to directly deduce the impact on the outgoing signal SS and thus predict what will be altered or not in the outgoing SS signal. In this case, if one of the downstream fault detectors DV1 to DVJ is a flow analyzer which detects excess flow for each of the components of the outgoing signal SS, the flow analyzer causes the generation of at least one alarm ASV service signal which signals a maximum flow threshold exceeded for at least one component and which, correlated with the possible ASE equipment service alarm in the COR correlator, produces an AS service alarm in step E29 to be displayed as a alphanumeric label in console C. For this example, the ASE alarm is not really produced by the FE filter and the COR correlator only finds the type dependent on the AS alarm to be displayed, which signals that at least the one of the components of the signal SS is likely to be fleeting and random given the risk of overflow of output at the output of the multiplexer considered.

According to other examples of removal of ambiguity of a dependent rule, the AS service alarm to be displayed in the console C results from the correlation of a possible ASE alarm and of several ASV alarms originating from several faults detected by several detectors. DVl downstream to DVJ, or else states at least the various downstream ASV service alarms generated by the FV filter, preceded by an ASE service alarm of generic formulation of the type "SS signal (service) configuration may not correspond to what it should be ", or is constituted by a single ASV downstream service alarm generated by the FV filter. Naturally, as before, a time delay as a function of the propagation time and of fault processing is provided in the correlator COR before processing ASV alarms to possibly correlate with an ASE alarm in order to constitute an alarm to display AS.

The filtering of alarm cascades resulting in an inhibition of alarms downstream of the place where the current fault was detected, in steps E13, E2β and E33, can occur on intra-equipment alarms and / or on inter-equipment alarms.

For example, an intra-equipment filtering rule results from the detection of an absence of an external clock at the input of a device. determined, such as the aforementioned multiplexer. The current fault message MFE relating to the multiplexer causes the emission of an equipment alarm AE by the filter FE signaling the absence of an external clock at the input of the multiplexer in step E22, then the emission of a ASE service alarm by the correlator COR to signal that the outgoing signal SS is absent at the output of the multiplexer in step E25, and the inhibition of the AE equipment alarms resulting from MFE equipment fault messages induced by the fault of current operation detected and already processed by the FE filter such as absence of output signal from the multiplexer or overflow of a FIFO memory included in the multiplexer, in step E26. According to an example of inter-equipment filtering rule, if the determined faulty equipment is an encoder, the current fault message MFE produced by an encoder fault detector and relating to an encoder supply failure, or an absence of signal d the clock at the output or inside the encoder generates an equipment alarm AE by the filter FE signaling the failure of the encoder in step E22. The filtering rule being still self-sufficient, the correlator then produces an ASE service alarm signaling that the signal SS is absent due to the absence of coding, in step E25. At the same time, fault detectors monitoring the operation of equipment located downstream of the encoder, such as a multiplexer and a switch connected in cascade to the encoder output, produce MFE malfunction messages induced by the observed absence of 'a signal entering the multiplexer. These equipment fault messages generate AE equipment alarms as well as possibly ASE service alarms. which are inhibited in step E26 by the COR correlator. Thus in this example, a fault in the encoder causes an inhibition of parasitic alarms in the multiplexer downstream of the encoder, induced by the fault in the encoder.

According to another aspect of the role of the COR correlator, the latter decides to replace a faulty item of equipment current Eq with identical standby item of equipment in response to alarms of equipment AE and / or service ASE, ASV predetermined. The correlator then controls a switch connected to the inputs of the faulty equipment and of the emergency equipment whose outputs are connected, or to the outputs of the faulty equipment and of the emergency equipment whose inputs are connected.

According to a preferred embodiment, FIGS. 3 and 4 schematically show the installation of a supervision system according to the invention with alarm detectors in a digital television transmitter EM. A bouquet of multiplex digital video signals is transmitted by the transmitter EM in the form of transport packets according to the digital television standard MPEG-2, multiplexed in an outgoing multiplex signal SS which is to be modulated in order to be transmitted to a broadcasting satellite digital television.

As shown in FIG. 3, the transmitter EM comprises several digital service channels which are packaged and multiplexed in a multiplexer MUX into an outgoing multiplex signal SS through a backup switch CS. The service channels correspond respectively to programs audiovisuals of a digital satellite television broadcasting operator managing the EM transmitter. An audiovisual program is supported by a composite digital video signal transmitted in the form of transport packets according to the MPEG-2 standard. For example, the multiplexer MUX comprises N input ports PE1 to PEN respectively allocated to N television programs, with 1 <N, a backup port PES to rescue one of the faulty service channels, and an input port PEA to receive a digital multiplex video signal from another operator if necessary.

The MUX multiplexer is essentially associated with three pieces of SIMS, DM and CTA equipment relating to signaling and scrambling in the SS signal. The SIMS (Signaling Management System) equipment manages audiovisual programs transmitted in the SS signal in order to describe them and program events in them according in particular to an event information table EIT (Event Information Table). The DM equipment is a messaging broadcaster that sends user rights to authorize access to certain programs. The CTA equipment is an access title controller which controls the scrambling of predetermined audiovisual programs.

The switch CS at the output of the MUX multiplexer comprises two inputs respectively connected to the MUX multiplexer and to a backup MUXS multiplexer also connected to the input ports of the MUX multiplexer in order to replace the latter when it fails under the control in particular of the DS supervision.

As shown in the input port service channel En in Figure 3, each service channel comprises a switching gate GR having several inputs respectively connected to at least M AVA audio video acquisition equipment, only one of which is shown in FIG. 3. Each AVA equipment formats the various components of a composite digital video signal relating to a service, for example the video, audio and teletext components according to the 4: 2: 2 luminance and chrominance coding format and the format of the elementary packets according to the MPEG-2 standard. For example, some AVA acquisition equipment are respectively connected to cameras relating to an audiovisual program so that the switching grid GC switches one of the corresponding audiovisual signals to the output of the grid which is connected to the corresponding input of the MUX multiplexer through a COD coder. Preferably, an input of the grid GC is connected to an AVAS emergency audio video acquisition device so that it replaces one of the AVA devices whose operation has become faulty under the control in particular of the DS supervision device.

The main functions of the COD encoder are compression of the data flow leaving the switching grid GR having a very high bit rate, typically 270 Mbit / s, in a relatively low bit rate of the order of a few Mbit / s applied to the port. corresponding input PEn of the multiplexer MUX, and the introduction of signaling specific to the corresponding service in the form of a standardized table PSI (Program Specifies Information) such as PAT and PMT tables according to the MPEG-2 standard.

The EM transmitter also includes a GC channel manager which is connected to most of the aforementioned equipment included in the EM transmitter in order to program various parameters for configuring each television program service to be multiplexed in the multiplexer MUX as an outgoing signal SS. In addition, the channel manager GC cooperates with the supervision device DS according to the invention to replace a faulty item of equipment determined by an identical standby item of equipment, by commanding a switching in the switching grid GR to the standby acquisition device. AVAS, or a switch in the MUX multiplexer to the PES emergency input port, or a switch in the switch CS to the MUXS emergency multiplexer according to the MFM, MFE, MFV fault messages processed by the DS device.

According to the invention, three equipment malfunction detectors DE1, DE2 and DE3 are respectively integrated into the AVA, GR and COD equipment of a service channel PEn and six other equipment malfunction detectors DE4 to DE9 are respectively integrated in the MUX multiplexer, the SIMS, DM and CTA equipment, the CS switch and the CG manager. As already said, these fault detectors are in the form of SNMP software agents implemented in the aforementioned respective equipment of the emitter EM to be consulted by the supervision device DS.

In general, each equipment malfunction detector DE1 to DE9 is capable of causing generation by the equipment fault filter FE of several equipment alarms AE due to a malfunction of a specific equipment in which the detector is integrated. The AE alarm can signal a loss or alteration of the signal leaving the determined equipment; a non conformity of the clock signal entering the determined equipment or of or one of the signals entering the determined equipment causing loss or alteration of the signal leaving the equipment and likewise, a non-conformity of the one of the audio, video and teletext components of the or one of the signals entering the equipment, which signals a loss or alteration of the component; incorrect configuration of the MUX multiplexer causing loss or alteration of an audio, video and teletext component of the outgoing signal; a bad configuration of the MUX multiplexer or of the GC channel manager, or a malfunction of the CTA controller or a communication failure between two of these three equipments leading to an impossibility of scrambling of components or multiplexed signals in service; inability to load and / or retrieve a backup from the GC channel manager; exceeding a flow rate setpoint in a service channel or of a component on an input port PEn of the MUX multiplexer; overheating due to excessive temperature or a faulty ventilation of the equipment determined anticipating a malfunction of the equipment, etc. The filtering rules for the numerous equipment alarms set out above are self-sufficient.

The dependent rules are based for example on a communication failure between a given item of equipment and another item of equipment of the transmitter, in particular between one of the items of equipment GR, COD, MUX and CS and the channel manager GC; loss of trading options to be memorized by the GC channel manager; exceeding a flow setpoint for a input component of the MUX multiplexer; a malfunction of the multiplexer MUX or of the switch CS which can cause loss or alteration of the outgoing multiplex signal SS; a malfunction of the GC switching gate or of the COD encoder which could lead to loss or alteration of the composite signal leaving it; non-conformity of a signal at the input of AVA, COD or MUX equipment, such as loss of signaling or clock which could lead to a deterioration in the quality of the respective service; a malfunction of AVA or COD equipment that can lead to loss or alteration of a video or audio component, etc.

As shown in FIG. 4, the supervision system SUP for the emitter EM further comprises two types of quality fault detector upstream DVM and DAM as detectors DMI to DMI, and four types of fault detector downstream DVA , DAA, AF and SCA as detectors DV1 to DVJ.

A pair of upstream quality fault detectors DVM and DAM 'is introduced into each service channel PE1 to PEN of the transmitter EM, for example at the output of each AVA video or audio acquisition equipment. The DVM detector analyzes the quality of the video component at the output of the AVA equipment and produces MFM messages signaling any absence of program, synchronization or image, or poor quality of the image colors which generates two ASM service alarms by the FM filter. The DAM detector produces MFM messages signaling abnormal silences in the audio component, an absence of the latter or of the synchronization signal relating to it, or even faults in the audio component such as hissing, buzzing, saturation, right / left phase shift, lack of quality, which generates two respective ASM service alarms by the FM filter. DVA downstream quality fault detectors,

DAA, AP and SCA are for example introduced at the output of the multiplexer MUX or at the output of the switch CS.

The DVA and DAA detectors respectively detect quality faults in the video and audio components in the outgoing multiplex composite signal SS of the EM transmitter, signaled by MFV messages similar to those MFM produced by the upstream detectors DVM and DAM respectively which generates four ASV alarms by the FV filter. In addition, the DVA detector signals an insufficient bit rate in the components or a poor bit rate ratio between video components in the outgoing signal SS.

The AF detector is an MPEG flow analyzer which essentially detects syntax errors in PSI (Program Specifies Information) signaling tables according to the MPEG-2 standard transmitted in the transport packets making up the outgoing signal SS. Depending on the type of fault detected, the supervision device DS generates a service alarm AS signaling the loss of the output signal SS or a video or audio or teletext component in it, the loss of a signaling channel in it ci, the presence of unwanted packets in the SS signal, errors in the time distribution and in the bit rate of the SS signal or a component thereof, for example a bit rate exceeding a maximum threshold or a bit rate below a minimum threshold.

The SCA detector is an access control supervisor that checks predetermined data from management and access introduced through SIMS, DM and CTA equipment at the level of each multiplex television program in the outgoing signal SS. These data to be checked include the flow of a service between minimum and maximum limits, a scrambling period, and access rights to be transmitted. The SCA supervisor generates several service alarms by the DS device.

As regards the COR correlator in the supervision device DS linked to the video transmitter EM, the COR correlator ignores any alarm AE, AS and ASV resulting from a fault message MFE, MFV, in response to an upstream alarm ASM produced by the FM filter in accordance with step E13. Each of the four ASM service alarms produced by the DS device then concerns a loss of a video or audio component at the input of the transmitter, or poor quality of the video or audio component at the input of the transmitter.

When the filtering rule corresponding to an equipment alarm AE in the equipment fault filter FE is self-sufficient in response to one of the faults signaled by a determined DEq of the detectors DE1 to DE9 in the transmitter EM, the COR correlator ignores any AE, ASE and ASV alarm resulting from an MFE, MFV fault message produced by a fault detector downstream of the determined fault detector. In particular, the correlator COR ignores any alarm resulting from an equipment fault message MFE transmitted by one of the fault detectors DE (q + 1) to DEQ = DE9 relating to equipment downstream from the determined detector DEq, according to step E26. The self-sufficient rules signaled by an ASE service alarm correspond in particular to a loss of the outgoing multiplex signal SS due to the malfunction of the multiplexer MUX or a nonconformity of the clock signal at the input of the multiplexer; a loss of a composite signal in a service channel due to the malfunction of the AVA acquisition equipment or of the COD coder in the service channel or due to a nonconformity of the clock signal at the input of the COD coder or the composite signal at the input of the MUX multiplexer or else due to a bad configuration of the MUX multiplexer; loss of a video component in a service channel due to a non-conformity of the signal at the input of the AVA equipment, or to a malfunction of the video compressor in the COD encoder, or to poor communication between the compressor and the encoder of the service channel, or of a non-conformity of the signal at the input of the coder COD, or of a bad configuration of the multiplexer MUX; loss of an audio component in a service channel due to a nonconformity or absence of the signal at the input of the AVA acquisition equipment in this channel, or to the nonconformity of the signal at the input of the coder COD, or a malfunction of the COD coder, or a bad configuration of the MUX multiplexer; a loss of a teletext component in a service channel due to a non-conformity of the signal at the input of the AVA acquisition equipment or of the COD coder of this channel, or to the malfunction of the COD coder; loss of a signaling component due to incorrect configuration of the MUX multiplexer; impossible scrambling due to a configuration problem with the MUX multiplexer or the GC channel manager, or due to a communication problem between the multiplexer and the channel manager or between the multiplexer and the CTA access title controller; a scrambling stop due to a malfunction of the CTA controller; impossible scrambling due to a scrambling logon problem; a degraded mode of scrambling due to a communication problem between the multiplexer MUX and the channel manager GC or due to a malfunction of the CTA controller; a stopping of the broadcasting of the signaling components due to a bad configuration of the multiplexer MUX or to a problem of communication between this one and the broadcaster DM; management by SIMS equipment stopped; inability to load and / or retrieve a backup from the GC channel manager; a speed setpoint being exceeded in a data channel at the level of the MUX multiplexer; and anticipation of the malfunction of one of the AVA, COD, MUX and GC equipment due to overheating of it.

For other MFE equipment malfunction messages, the COR correlator applies dependent rules signaled by the FE filter which are less numerous than the self-sufficient rules. These dependent rules impose a service alarm signaling a frozen configuration due to a communication problem between the channel manager and one of the GR and COD equipment by correlation with ASV alarms resulting from MFV messages produced by the AF flow analyzer. , or between the channel manager and one of the MUX and CS equipment by correlation of ASV alarms resulting from MFV messages produced by the AF flow analyzer and the SCA supervisor; a frozen configuration due to a power supply failure of a GR switching or an AVA acquisition equipment or COD encoder configuration problem following a fault message produced by the AF flow analyzer; a frozen configuration due to a configuration problem in the MUX multiplexer or the GC channel manager by correlation with ASV alarms resulting from MFV messages produced by the AF analyzer and the SCA supervisor; exceeding a flow rate setpoint of a component at the level of the MUX multiplexer by correlation with ASV alarms resulting from MFV messages produced by the DVA, DAA and AF detectors; a possible loss or alteration of the outgoing multiplex signal SS from the transmitter due to the malfunction of the switch CS by correlation with an ASV alarm resulting from MSV messages produced by the AF flow analyzer; loss or alteration of the outgoing multiplex signal due to the malfunction of the MUX multiplexer by correlation with ASV alarms resulting from MFV messages produced by the DVA, DAA, AF and SCA detectors; loss or alteration of a composite signal in a service channel due to a malfunction of the GR switching grid by correlation with ASV alarms resulting from MFV messages produced by the AF flow analyzer; deterioration of the quality of a composite signal in a service channel due to non-conformity of the signal at the input of the AVA acquisition equipment by correlation of ASV alarms resulting from MFV messages produced by the DVA, DAA detectors and AF; an alteration in the quality of the multiplex signal in a service channel due to the malfunction of the COD coder or the MUX multiplexer by correlation with ASV alarms resulting from MFV messages produced by DVA, DAA and AF detectors; loss or alteration of the quality of a video component in a service channel due to the malfunction of the AVA acquisition equipment or of the COD coder in the service channel, by correlation with ASV alarms resulting from MFV messages produced by the DVA, DAA and AF; an alteration of a video component in statistical multiplexing based on the use of an HDLC bus between the coders COD, by correlation of ASV video alarms resulting from MFV messages produced by the DVA and AF detectors; alteration of a statistical multiplexing video component due _to a malfunction of the GC channel manager by correlation with video ASV alarms resulting from MFV messages produced by the VAD detector; an alteration in the quality of an audio component due to a non-conformity of the multiplex signal at the input of the coder COD by correlation of ASV audio alarms resulting from MFV messages produced by the DAA detector; and an alteration in the quality of an audio component due to the malfunction of a COD coder by correlation of ASV audio alarms resulting from MFV messages produced by the DAA and AF detectors.

The COR correlator also validates ASV alarms resulting from quality defect detections or loss of the video or audio component signaled by the DVA or DAA detector, by inhibiting the respective video or audio alarms possibly produced by the flow analyzer. AF. The correlator also ignores any possible ASV alarm produced by the SCA supervisor when it receives an ASV alarm resulting from an MFV message produced by the AF analyzer due to loss or desynchronization of the outgoing multiplex signal SS or a loss of a signaling path therein.

Claims

1 - System for supervising at least one item of equipment and a digital signal leaving the item of equipment, comprising a downstream detection means for detecting quality faults in the outgoing signal, and an equipment fault detector (DEq) for detecting operating faults (MFE) relating to the equipment ^' (Eq), characterized in that it comprises a first fault filtering means (FE) generating equipment alarms (AE) each in response to one detected respective operating faults of the equipment, a second fault filtering means (FV) generating downstream service alarms (ASV) each in response to one detected of respective quality faults (MFV) in the outgoing signal ( SS), a first decision means (TM, COR) generating a self-sufficient service alarm (AS) and inhibiting (E26) any downstream service alarm (ASV) generated by the second filtering means (FV) as long as the fault d equipment detected é (MFE) persists when the impact of the detected equipment failure is defined with certainty (E25) on the outgoing signal, and a second decision means (TM, COR) generating an alarm ^'service (AS) dependent (E29 ) any downstream service alarm (ASV) generated by the second filtering means (FV) as long as the detected equipment fault persists when the impact of the detected equipment fault is defined with uncertainty (E27) on the outgoing signal .

2 - System according to claim 1, wherein the self-sufficient service alarm (AS) is confused with an equipment alarm (AE). 3 - System according to claim 1 or 2, wherein the dependent service alarm (AS) consists of a single downstream service alarm

(ASV) generated by the second fault filtering means (FV) or else states different downstream service alarms (ASV) generated by the second fault filtering means (FV).

4 - System according to any one of claims 1 to 3, wherein the generated service alarm (AS) relates to a multiplexed signal in the outgoing signal (SS), or to one of the components of the outgoing signal (SS).

5 - System according to any one of claims 1 to 4, for supervising several pieces of equipment (El-EQ) and at least the outgoing signal

(SS) of all the equipment, characterized in that it comprises equipment fault detectors (DE1-DEQ) for detecting operating faults (MFE) relating respectively to the equipment (El- EQ), the first fault filtering means (FE) generates equipment alarms (AE) relating respectively to sets of respective equipment malfunctions, and the first decision means (TM, COR) also inhibits all service alarms (AE) , ASE) resulting from equipment faults (MFE) relating to equipment

(E (q + 1) -EQ) located downstream of the equipment (Eq) in which the equipment fault corresponding to the generated self-sufficient service alarm (AS) was detected.

6 - System according to claim 5, wherein the first decision means (TM, COR) inhibits also equipment alarms (AE) relating to a given item of equipment resulting from equipment faults induced by a detected equipment fault relating to the item of equipment determined and processed by the first fault filtering means (FE).

7 - System according to claim 5 or β, wherein the first decision means (TM, COR) inhibits equipment alarms (AE) resulting from equipment faults (MFE) induced by an equipment fault relating to determined equipment and detected by fault detectors relating to equipment located downstream of the determined equipment.

8 - System according to any one of claims 1 to 7, in which the first and second decision means (TM, COR) replace faulty equipment (Eq) with emergency equipment in response to equipment alarms and / or predetermined service (ASE, ASV).

9 - System according to any one of claims 1 to 8, in which an equipment fault detector (DEq) relating to a given piece of equipment (Eq) detects at least one of the following equipment faults (MFE) : malfunction of the determined equipment, absence or non-conformity of a data signal entering or leaving the determined equipment or of a multiplex signal or of a component of the data signal, power supply failure of the determined equipment, absence of a clock at the input of the determined equipment or inside the determined equipment, overflow of the signal rate entering the determined equipment or of a component thereof ci with respect to a minimum threshold or a maximum threshold.

10 - System according to any one of claims 1 to 9, wherein the downstream detection means comprises several downstream quality fault detectors (DVl-DVJ) in cascade to each detect one or more respective quality faults (MFV) in the outgoing signal (SS).

11 - System according to claim 10, comprising as many downstream quality fault detectors (DVA, DAA) as components or multiplexed signals in the outgoing signal (SS) to detect respectively quality faults in the components or in the multiplex signals.

12 - System according to claim 10 or 11, wherein a downstream quality fault detector (DVj) detects at least one of the following faults: absence or insufficient level of the outgoing signal (SS) or of a component or d 'a multiplex signal in the outgoing signal, lack of synchronization of the ^' outgoing signal or one of its components with a local clock, insufficient flow of the outgoing signal or of a component of the outgoing signal, quality defects depending on the nature of the data supported by the outgoing signal.

13 - System according to any one of claims 1 to 12, comprising at least one upstream detector (DM1-DMI) for detecting quality faults (MFM) in an incoming signal (SE) of the equipment or of several equipment (El-EQ), and a third fault filtering means (FM) generating upstream service alarms (ASM) each in response to one detected of respective quality faults (MFM) in the incoming signal, and a third decision means (TM, COR) inhibiting (E13) any equipment alarm (AE) generated by the first fault filtering means (FE), any self-sufficient service alarm (AS) generated by the first decision means, any dependent service alarm

(AS) generated by the second decision means and any downstream service alarm (ASV) generated by the second fault filtering (FV) as long as a quality fault (MFM) detected by the upstream detector (DM1-

DMI) persists.

14 - System according to claim 13, comprising as many upstream quality fault detectors (DVM, DAM) as components or multiplex signals in the incoming signal (SE) to detect respectively quality faults in the components or in the multiplex signals.

15 - System according to claim 13 or 14, in which an upstream quality fault detector (DVi) detects at least one of the following faults: absence or insufficient level of the incoming signal (SE) or of a component or d '' a multiplex signal in the incoming signal, lack of synchronization of the incoming signal or one of its components with a local clock, insufficient flow of the incoming signal or of a component of the incoming signal, quality defects depending on the nature data supported by the incoming signal.

16 - System according to any one of claims 1 to 15, supervising several equipment (AVA, GR, COD, MUX, SIMS, DM, CTA, CS, GC) in a digital television transmitter (EM).

17 - System according to claim 16 and to any one of claims 13 to 15, comprising upstream quality fault detectors (DVM, DAM) for detecting quality faults (MFM) respectively in incoming composite signals, or in components of composite signals entering the transmitter.

18 - System according to claim 16 or 17 and to any one of claims 10 to 12, comprising downstream quality fault detectors (DVA, DAA) for detecting respectively quality faults and insufficient flow in components outgoing multiplex (SS) composite signal from the transmitter.

19 - System according to any one of claims 16 to 18, comprising a flow analyzer (AF) as a downstream quality fault detector for detecting syntax faults in signaling tables transmitted in packets making up the signal outgoing (SS).

20 - System according to any one of claims 16 to 19, comprising an access control supervisor (SCA) as a downstream quality fault detector for checking predetermined management and access data introduced by equipment. (SIMS, DM, CTA) of the transmitter in the outgoing signal (SS). 21 - Supervisory device (DS) for supervising at least one item of equipment and a digital signal leaving the item of equipment, characterized in that it comprises a first fault filtering means (FE) generating equipment alarms (AE) each in response to one of the respective operating faults (MFE) of the equipment detected by an equipment fault detector (DEq) relating to the equipment (Eq), a second fault filtering means (FV) generating downstream service alarms

(ASV) each in response to one of respective quality faults (MFV) in the outgoing signal (SS) detected by a downstream quality fault detector, a first decision means (TM, COR) generating a service alarm self-sufficient (AS) and inhibiting (E26) any downstream service alarm (ASV) generated by the second filtering means (FV) as long as the detected equipment fault (MFE) persists when the impact of the detected equipment fault is defined with certainty (E25) on the outgoing signal, and a second decision means (TM, COR) generating a service alarm (AS) dependent (E29) on any downstream service alarm (ASV) generated by the second filtering means (FV) as long as the detected equipment fault persists when the impact of the detected equipment fault is defined with uncertainty (E27) on the outgoing signal.

22 - Device according to claim 21, for supervising several pieces of equipment (El-EQ) and at least the outgoing signal (SS) of all of the pieces of equipment, in which the first fault filtering means (FE) generates alarms d 'equipment (AE) relating respectively to sets of operating faults (MFE) respectively detected by equipment fault detectors (DE1-DEQ) relating to equipment (El-EQ), and the first decision means (TM, COR) also inhibits all service alarms (AE, ASE) resulting from equipment faults (MFE) relating to equipment (E (q + 1) -EQ) located downstream of the equipment (Eq) in which the equipment fault corresponding to the generated self-sufficient service alarm (AS) has been detected.

23 - Device according to claim 21 or 22, comprising a third fault filtering means (FM) generating upstream service alarms (ASM) each in response to one of respective quality faults (MFM) in an incoming signal equipment or more equipment (El-EQ), detected by at least one upstream quality defect detector (DM1-DMI) (MFM), and a third decision means (TM, COR) inhibiting (E13) equipment alarm (AE) generated by the first fault filtering means (FE), any self-sufficient service alarm (AS) generated by the first decision means, any dependent service alarm (AS) generated by the second means of decision and any downstream service alarm (ASV) generated by the second fault filtering (FV) as long as a quality fault (MFM) detected by the upstream detector (DM1- DMI) persists.