FR2867646A1 - Multi-channel signal transferring method for digital video broadcasting network, involves replacing identifiers for components in signal modulating frequency, by identifiers in table extracted from signal modulating test frequency - Google Patents

Abstract

The method involves tuning a receiver to a test frequency, when a parameter of a reference signal not satisfies a preset condition. The parameter is evaluated for the frequency. Packet identifiers for television service components in the signal modulating a frequency are replaced, by identifiers in a table extracted from the signal modulating the test frequency when the parameter satisfies the condition, to configure decoders.

Description

Video broadcast network multiplex transfer

  The present invention generally relates to a digital video broadcast network between terrestrial multiplex signal transmitters and user receivers. The network is particularly intended to broadcast digitally from transmitters television program services according to the European standard DVB-T (Digital Video Broadcasting Terrestrial) or DVB-H (Digital Video Broadcasting Hand-Held).

  The invention relates more particularly to the continuity of the audio, video and data components of a reference service consumed in a digital television receiver that is mobile in the network.

  The ETSI TR 101 211 V1.5.1, "Digital Video Broadcasting (DVB)" report, May 2002, pages 37-45, recommends in an Integrated ReceiverDecoder (IRD) receiver to automatically select and tune to a different frequency than a reference multiplex signal supporting a reference service during consumption, or at a frequency of another multiplex signal supporting the reference service, for a multiplex signal transfer (hand-over). However, this report does not provide a means to effectively perform this transfer, in particular without resorting to a cellular architecture of the digital video broadcasting network, or to a geographical positioning of the mobile receiver with respect to a geographical location of terrestrial transmitters of the broadcast network.

  The present invention aims at providing a multiplex signal transfer method for automatically selecting another frequency broadcasting the reference multiplex signal, or possibly a frequency broadcasting another multiplex signal supporting the reference service, in order to ensure the continuity of the multiplex signal. reference service in the mobile receiver.

  To this end, a multiplex signal transfer method in a mobile digital television receiver tuned to a first carrier frequency of a reference multiplex signal supporting a first table associating identifiers of several multiplex signals respectively to frequency lists. test carrier and a second table defining components of a reference service consumed in the receiver and supported by the reference multiplex signal, characterized in that it comprises a tuning of the receiver at a test frequency and according to characteristics modulation values read in the first table when at least one sequentially evaluated transfer parameter relative to the reference multiplex signal modulating the first frequency does not satisfy a predetermined condition, an evaluation of the transfer parameter for the reference multiplex signal modulating the frequency of test, and one replaced encoding packet identifiers relating to reference service components in the reference multiplex signal modulating the first frequency, by those read in the second extracted table of the reference multiplex signal modulating the test frequency when the evaluated transfer parameter satisfies the predetermined condition for configuring decoders.

  In general, the reference service is a television service combining audio and video components and possibly data, although it can be reduced to data only.

  The transfer parameter can be one of several parameters. A parameter may be relative to a synchronization of the receiver for which the predetermined condition is satisfied when the receiver has acquired correct first bytes detected in a predetermined number of consecutive packets in the reference multiplex signal. Another parameter may be a signal to noise ratio for which the predetermined condition is satisfied when it is greater than a minimum signal-to-noise ratio. Another parameter may still be a bit error rate for which the predetermined condition is satisfied when it is less than a maximum bit error rate. A fourth parameter may be a number of uncorrected blocks of predetermined length after decoding in the reference multiplex signal for which the predetermined condition is satisfied when it is less than a maximum number of uncorrected blocks.

  In order to detect a change of cell during moving of the mobile receiver, the method of the invention comprises, together with the sequential evaluation of said at least one transfer parameter, or more generally of all the transfer parameters relating to the multiplex signal of reference modulating the first frequency, comparing the identifier of the reference multiplex signal stored in the mobile receiver to the multiplex signal identifier in the multiplex signal packets received by the mobile receiver in order to proceed to a tuning of the mobile receiver to the test frequency and an evaluation of the transfer parameter for the reference multiplex signal modulating the test frequency when the compared identifiers are different.

  As long as the evaluated transfer parameter for the reference multiplex signal does not satisfy the predetermined condition, the evaluation of the at least one transfer parameter can be iterated several times for the test frequency, and / or for each of several frequencies. in the first table, and / or for the reference multiplex signal with several associated test frequencies.

  The evaluation of the at least one transfer parameter can be iterated several times for at least one test multiplex signal whose identifier is included in the first table and is associated with the identifier of the reference service in a third extracted table. multiplex test signal and describing services offered by the test multiplex signal when the predetermined condition is not satisfied by the evaluated transfer parameter for the reference multiplex signal. In this case, the method rejects the test multiplex signal frequencies that do not support the reference service.

  The method may also comprise a replacement of packet identifiers relating to components of the reference service in the reference multiplex signal modulating the first frequency, by those provided by a specific application external to the transfer and for example resulting from a zapping in the receiver.

  Other characteristics and advantages of the present invention will appear more clearly on reading the following description of a number of preferred embodiments of the invention, by way of non-limiting examples, with reference to the corresponding appended drawings in which: FIG. 1 is a diagram of two neighboring cells in the network; Figure 2 is a schematic block diagram of a mobile digital television user receiver in a terrestrial digital video broadcasting network; FIG. 3 is an algorithm illustrating the multiplex signal transfer method according to the invention; and FIG. 4 is a transfer step algorithm for searching for a reference service on another frequency of a current reference multiplex signal or in a test multiplex signal other than the reference multiplex signal, in the method of transfer according to the invention.

  Some concepts and parameters relating to a digital television signal broadcast by a terrestrial transmitter of the repeater (relay) or wireless transmitter (gap fillers or transmission sites) type in a DVB-T digital terrestrial video broadcasting network are described below. according to the MPEG-2 standard and can be received by a mobile receiver of digital television user RE. For example, the transmitter transmits four digital television signals each supporting eight program services, ie 32 services.

  Each digital television signal broadcast by the transmitter modulates a carrier at a respective frequency typically in QAM quadrature and amplitude modulation or QPSK four-phase modulation. The digital television signals can be broadcast by a common transmitter according to different modulations. The channel coding in the transmitter is for example a Reed Solomon coding accompanied or not by a convolutional coding, for example of the Viterbi type.

  A digital television signal is a multiplex signal TS (Transport Stream), also called "multiplex", supporting the flow of all digital data of several services in a physical channel. In general, a service is a sequence of programs of a broadcaster, a television channel, comprising three components: a video component, an audio component and, where appropriate, a component of auxiliary data such as teletext, high-speed data IP (Internet Protocol) and selective data for interactive video and / or audio services; however a service may be restricted to the audio or auxiliary data component. The multiplex signal also supports particular signaling tables PSI (Program Specific Information) associated with these services including four PAT, PMT, SDT and NIT relate more particularly to the present invention.

  The service components and the signaling tables are transmitted in the form of transport packets having a constant length, typically 188 bytes, composing the multiplex signal TS.

  The DVB-T broadcast network is divided into 35 cells which are geographical areas each covered by one or more transmitters each broadcasting multiplex signals on different frequencies. Two neighboring cells sharing a multiplex signal broadcast it on different frequencies. For example, as shown in FIG. 1, emitters EM1 in a cell C1 emit two multiplex signals TS1 and TS2 respectively on different frequencies F1 and F2, and emiters EM2 of a cell C2 adjacent to the cell C1 emit the two multiplex signals TS1 and TS2 respectively on frequencies F3 and F4 different from the frequencies F1 and F2.

  As will be seen hereinafter, the transfer according to the invention makes no use of any characteristic of the geographical location of the cells, nor a geographical positioning of the mobile receiver with respect to the cells.

  The mobile receiver RE, also known integrated receiver-decoder IRD (Integrated Receiver-Decoder), shown schematically in Figure 2 essentially comprises a tuner TU connected to an antenna and tunable programmable to the carrier frequency F d a reference multiplex signal TS, a DMD demodulator for Coded Orthogonal Frequency Division Multiplex (CMD) producing transport packets included in the multiplex signal, and a DMUX demultiplexer-demultiplexer decrypting and decrypting, if requested, the transport packets received to reconstruct elementary packets, as well as a time base BT and a CPU unit UC such as a microprocessor connected to the previous elements.

  The elementary packets are partly respectively associated with the audio, video and data components of a user-selected MPEG-2 audiovisual reference service and applied to three decoders D1, D2 and D3 and partly relating to the signaling associated with the signals. programs and applied through the central unit to an RTAB signaling table recovery circuit that reconstruct the signaling tables in the receiver. The decoder D1 renders stereophonic components to two speakers HP through a specific digital-to-analog converter (DAC) COI. The decoders D2 and D3 render three video components and auxiliary data to an EC television screen through a specific digital-to-analog converter CO23.

  The frequency of the reference multiplex signal is selected initially by the user by selecting a reference service in a window displayed on the EC screen by means of a TC remote control with infrared or radio proximity link with a local reception circuit RL connected to the central unit UC, or during a transfer according to the invention following a movement of the receiver RE.

  As will be seen below, the central processing unit UC constantly monitors that the reference multiplex signal is the current multiplex signal received by the receiver.

  Each transport packet consists of a four-byte EN header 01 to 04 and a 184-byte CD data field.

  The first byte of the header is a Sync Byte whose value is normally equal to 47 'in hexadecimal code. The first byte in the transmitted packets TS is detected at the output of the DMD demodulator by the time base BT to synchronize the three decoders D1, D2 and D3 in the receiver RE. The time base considers the synchronization as acquired, that is to say, locked, when correct first bytes are detected in a predetermined number K of consecutive packets of the current multiplex signal TS, and as lost in the opposite case . K is a predetermined integer io for example equal to 5.

  The second byte of the header contains in particular a bit of transport error indicator, as the first bit, which constitutes a flag used to indicate the presence of erroneous bits in the corresponding packet.

  The last five bits of the second octet and the third octet of the header contain a 13 bit Pid packet identifier. Pid packet identifiers are different for the components of a service. A packet identifier for a given component of a given service may vary from one multiplex signal (transport stream) in one cell to another multiplex signal in another cell in the broadcast network and, of course, between network cells. different broadcast.

  The last four bits of the fourth octet of the header constitute a 4-bit continuity count relating to a continuity counter in the timebase which is incremented by one modulo unit 16 for each packet corresponding to the identifier of a component of a respective service.

  The signal tables supported by a multiplex signal allow the RE receiver to identify different parameters and components for accessing the initial audiovisual program services.

  The Program Association Table (PAT) association table contains a list of all audiovisual service programs in correspondence with Sid packet identifiers for Program Map Table (PMT) program description tables associated with services designated by lo Sid identifiers. Each PMT table contains Pid packet identifiers relating to the audio, video and data components of a respective service supported by the multiplex signal and descriptors of the service components, as well as i5 Pid packet identifiers for the transmission of values. program clock reference numbers associated with the respective program for retrieving the transmitter clock from the time base BT. The PMT table is thus essential for the decoding of an audio and video service in the decoders D1 to D3 and enables the central processing unit UC to follow a service during a transfer (hand-over) from the reference multiplex signal. to another according to the method of the invention. If the PMT is invalid or contains errors, a decoder in the RE receiver is unable to select and decode a service component by the multiplex signal.

  The PAT table is transmitted by packets having Pid identifiers equal to 00 'in hexadecimal code. The PMT is transmitted by packets with variable Pid identifiers ranging from 0020 'to 1FFE' in hexadecimal code.

  The PAT and PMT tables as well as the SDT and NIT tables are transmitted periodically, for example every 10 seconds, to be saved by the RTAB signaling table recovery circuit.

  An SDT service description table

  (Service Description Table) is only associated with one

  respective multiplex signal. It contains the identifier TSid of the respective multiplex signal and the identifier ONid of the terrestrial digital video broadcasting network broadcasting it and the lo identifiers Sid of the services offered by the respective multiplex signal and in particular the type of a service, the service name and service provider.

  It will be assumed that the SID of a given service remains unchanged in the multiplex signals broadcast in the same network; however, in the opposite case infrequent, the invention uses a specific application "external transfer" so as to identify the desired service in all the multiplex signals the offerer.

  The identifier of the SDT table is equal to 42 'or 46' in hexadecimal code.

  The network information table (NIT) contains in association with the identifier TSid of each of the multiplex signals TS broadcast by one or more broadcast networks the list of all the carrier frequencies F on which the respective multiplex signal is broadcast and therefore in particular the TSid identifier of the reference multiplex signal TS in the receiver. Indeed the frequency of a multiplex signal varies from one cell to a neighboring cell in a given network when the reference multiplex signal is broadcast in the neighboring cell, and varies from one cell in a given network to a neighboring cell in a neighboring network when the reference multiplex signal is broadcast in the neighbor cell of the neighboring network. The NIT table also includes modulation characteristics of each multiplex signal.

  Thanks to the NIT table, the unit UC finds the reference service Sid during consumption in the mobile receiver RE on another frequency of the same multiplex signal or on the frequency of another multiplex signal in the same network or in the same network. a neighboring network.

  The identifier of the NIT table is 40 'or' 41 '.

  As shown in FIG. 3, the hand-over method essentially comprises the steps E0 to E8 to ensure the continuity of the reception of a reference program service S1 multiplexed initially in a reference multiplex signal TS on a first carrier frequency F that the mobile receiver RE receives. The method is essentially in the form of an API (Application Programming Interface) program implemented in the CPU.

  In the initial step E0, it is assumed that the central processing unit UC has memorized all the packet identifiers relating to the reference program service currently displayed on the screen EC, ie the network identifier ONID. initial digital terrestrial video broadcast, the TSid identifier of the reference multiplex signal TS, the identifier Sid of the reference service and the Pid identifiers of the components of the reference service. The tuner TU is tuned to the first frequency F of the reference multiplex signal TS.

  The above reference identifiers may result from a specific application "external to the transfer" following a change of service controlled by the remote control TC in the local reception circuit RL in particular during a zapping or an interruption of service.

  The steps E1 to E8 are repeated.subsequely according to a loop of variable duration from a few hundred milliseconds to a few tens of seconds depending on the result of conditional steps for a received current multiplex signal TS by the receiver RE and transmitted in a current network . The identifiers TSid and ONid of the current multiplex signal and the current network are merged with those of the reference multiplex signal and the reference network at the initial step E0.

  In step E1, the CPU UC reads in the PAT program association table recently retrieved from the current multiplex signal by the recovery circuit RTAB the identifier of the PMT program description table associated with the identifier Sid of the reference service so that the recovery circuit RTAB delivers the Pid packet identifiers relating to the audio, video and data components of the reference service. The central processing unit UC compares the identifiers initially stored Pid relative to the components of the reference service with the identifiers read in the PMT recently retrieved and relating to the components of the current multiplex signal received by the DMD demodulator for the reference service, at the step E2.

  If at least two compared component identifiers are different, the CPU unit changes the component Pid packet identifiers to a step E21 so that the identifiers of the reference service components are those of the current service received. This change may result from a multiplex signal transfer according to the invention as will be described later. The unit UC applies the identifiers of the components of the service which have become reference respectively to the decoders D1 to D3 in order to reconfigure them, if necessary according to another tested carrier frequency and / or another tested multiplex signal supporting the service. reference to a step E22, as will be explained below. In the case of the specific "external" application, the tuner TU and the demodulator DMD are tuned to the frequency and modulation characteristics of the multiplex signal providing the service which has become reference which has been selected in the receiver by the user at the the remote control TC, and the tables are erased in the RTAB circuit so that the latter retrieves the tables corresponding to the reference service that has been selected.

  After step E22, or after at step E2 when the component-related packet identifiers have not changed, the RTAB recovery circuit attempts to retrieve the SDT service description table in the current multiplex signal received during a predetermined predetermined period of time At, typically from 1 s to about 1.5 s, in step E3. If no SDT table is retrieved and recovered, the process proceeds to step E5. On the other hand, if the recovery circuit RTAB retrieves a table SDT during At, the unit UC updates the table SDT: the multiplex signal identifier TSid and the broadcast network identifier ONid in the table recently retrieved SDT in correspondence with the identifier Sid of the reference service are read and saved in step E4 for subsequent comparison with the identifiers of the reference multiplex signal and the reference broadcast network in step E7.

  Then in the next step E5, the recovery circuit RTAB also attempts to update the NIT network information table after the previous refresh of the SDT table, by extracting the NIT table in the current multiplex signal received during a predetermined predetermined time period At 'which may be equal to or different from At. If no NIT table is retrieved and retrieved, the method proceeds to step E7. On the other hand, if the recovery circuit RTAB retrieves a table NIT during At ', the unit UC updates the table NIT: the values of the carrier frequencies and of the modulation characteristics of the current multiplex signal TS and more generally the values of the frequencies of carrier and the modulation characteristics of all the multiplex signals in at least the current network and neighboring networks are extracted from the last-retrieved table NIT in correspondence with the identifier TSid of the current multiplex signal and record them as multiplex signal characteristics reference in the RTAB circuit by overwriting the old ones in step E6.

  The central processing unit UC then proceeds to evaluate transfer parameters in step E7 so as to decide whether a transfer of the reference multiplex signal to another frequency thereof or to another multiplex signal supporting the reference service. must be executed.

  The transfer parameters are four in number: - a SYNC parameter relating to a synchronization of the receiver with respect to the transmitters of the network, continuously monitored by the time base BT; the SYNC parameter is in the "1" state when the BT timebase in the receiver has acquired locking synchronization on correct first bytes detected in K Io consecutive packets in the received current multiplex signal TS; the parameter SYNC is in the state of synchronization loss "0" when the time base BT detects at least a single first incorrect byte in K consecutive packets; a SNR average signal-to-noise ratio measured every second that the BT time base permanently estimates at the output of the tuner TU and compares with a predetermined minimum signal-to-noise ratio SNRmin, for example between about 15 dB and about 25 dB, in beyond which the current multiplex signal is unusable in the receiver RE, meaning that the current modulated multiplex signal is received with insufficient power; a bit error rate (BER) that the BT time base continuously detects in the bits (symbols) at the output of the DMD demodulator and is incapable of correcting in the current multiplex signal TS; the timebase compares the average BER for a predetermined time, in this case 30 since the last rate estimate in step E7 or step E80, to a predetermined maximum bit error rate BERmax typically 2 10 4 beyond which a transfer must be sought; and a number of uncorrected UNC blocks (uncorrected) in the reference multiplex signal TS at the output of the DMD demodulator after Reed-Solomon and Viterbi decodings; each block to a predetermined length of symbols; the time base BT has a number of uncorrected average UNC blocks periodically in the current multiplex signal received for a predetermined duration and the predetermined maximum number of uncorrected blocks UNCmax beyond which a transfer must be sought.

  Alternatively, one or two or three of the four previous transfer parameters or other similar parameters are monitored and evaluated by the central processing unit UC.

  Further, in step E7, the CPU CPU compares the stored reference identifiers TSid and OSid with the multiplex signal and network identifiers in the packets of the received current multiplex signal in order to proceed with a transfer if the compared identifiers are different. . This means that the mobile receiver RE has moved to another cell using the same carrier frequency F but with another multiplex signal.

  If the four transfer parameters satisfy the above predetermined transfer conditions, either first correct bytes detected in K consecutive packets in the current multiplex signal TS, an average SNR greater than SNRmin, a BER average BER less than BERmax, and a number of uncorrected blocks UNC less than UNCmax, and if the current multiplex signal and the current network are indeed the reference multiplex signal and the reference network, then the unit UC executes again the loop of sequential steps El at E7.

  On the other hand, if one of the five predetermined conditions preceding step E7 is not satisfied, the central processing unit UC attempts a transfer of the current multiplex signal TS by changing the frequency and / or by changing the multiplex signal supporting the service. current in step E8 which is composed of steps E80 to E87 shown in FIG. 4.

  In step E80, the CPU stores the identifier of the reference multiplex signal TS1 as a test multiplex signal identifier (TSid). Then the unit UC selects in step E81 a first carrier frequency Ftest from the list in the NIT table last saved in step E6 in association with i5 the identifier (TSid) test and reconfigures in step E82 the tuner TU to match the test frequency Ftest according to modulation characteristics read from the NIT table. A TEMP timeout of a few hundred milliseconds is triggered in the CPU. During the delay, the four transfer parameters SYNC, average SNR, mean BER and average UNC are evaluated in the CPU unit for the test frequency Ftest until the expiry of the timer in step E83. If the four previous conditions applied to the evaluated parameters are satisfied, the CPU searches for the reference service in the SDT table associated with the multiplexed signal that is current designated by the test identifier (TSid) TS, at a step E831. If the identifier Sid of the reference service is found, the unit UC replaces the identifiers of the reference multiplex signal TSid and of the reference network ONid and the frequency F of the reference multiplex signal by the identifiers (TSid) test and (ONid test and the test frequency Ftest of the multiplex signal become current at a step E832, and the transfer method returns to the step E1 for another execution of the loop E1 to E8. Otherwise, the process proceeds from step E832 to step E85.

  As long as the evaluated transfer parameters do not satisfy at least one of the four preceding conditions in step E81, the CPU unit iterates I times the transfer parameter evaluation steps E82 and E83 for the same test frequency Ftest. I is an integer for example equal to 1 or 2.

  If, after the iterations on the frequency Ft in step E81, the reception of the current multiplex signal TS is unsatisfactory, or if the identifier Sid of the reference service is not found in the table SDT associated with the current test multiplex signal in step E832, the CPU decides to test a next carrier frequency, if present, read in association with the test identifier (TSid) of the test multiplex signal in the saved table NIT, at steps E85 and E851. Steps E82 to E84, or E82 to E831, are performed again and are repeated for other carrier frequencies read in the backed up table NIT of the reference multiplex signal as long as the conditions on the evaluated transfer parameters are not satisfied. in step E83.

  If in step E85 the I iterations for each of the test frequencies F t is associated with the test identifier (TSid) of the test multiplex signal have been tested in vain, the transfer conditions not being fulfilled, at most J iterations test steps E81 to E85 are iterated for the test multiplex signal, as illustrated by step E86 in Fig. 4, as long as the evaluated transfer parameters do not satisfy the transfer conditions. The integer J is for example equal to 1, 2 or 3.

  As a variant for J = 2, the first iteration of the steps E81 to E85 for the test frequencies s Ftest is faster than the second iteration of the steps E81 to E85, the delay TEMP for each of the test frequencies during the first iteration being less longer than the delay during the second iteration. More generally, the timer increases from one iteration of steps E81 to E85 to the next.

  If the iterations for the current test multiplex signal TS for all frequencies modulated by it have produced no transfer parameters satisfying the respective transfer condition, and the unit UC notes in step E87 that all the multiplex signals have not been tested, it selects in step E871 the identifier TSid of another multiplex signal TS following that (TSid) test of the current test multiplex signal which has just been tested, for example according to a predetermined order of priority, in the NIT table of the reference multiplex signal recently saved in step E6. This other multiplex signal becomes the current test multiplex signal. The carrier frequencies F in association with the test identifier (TSid) of the current test multiplex signal are read one after the other in the NIT table last saved in step E6, executing for each of them the steps E81. at E85 as long as the transfer conditions on the transfer parameters are unsatisfied.

  Finally, after the execution of steps E81 to E87, if the CPU has selected a frequency of a current test multiplex signal for which the transfer conditions are satisfied in step E83, the CPU executes steps E831 and E832. The unit UC updates the PID packet identifiers relating to the audio, video and / or data components of the reference service in step E21 by replacing them with those stored and read in the PMT program description table which is designated in the PAT table associated with the current test multiplex signal, by the current service identifier Sid for the current test multiplex signal, the PAT and PMT tables having been retrieved and saved in a step El which has just been executed. Then in step E22, the identifiers of the current service components are applied by the CPU unit to the decoders D1 to D3 to reconfigure them so as to continue to reproduce the current service by means of the EC screen and the loudspeakers. HP, but with better quality of multiplex signal reception than before.

  Also some counters, such as a continuity counter, internal to the time base and the central unit are reset at each change of multiplex signal selected in step E21 to promote the current multiplex signal during the next loss of time. multiplex signal in step E8.

  If the transfer conditions have never been satisfied after the iterations at the last step E87 for each of the test multiplex signals identified in the NIT table and supporting the reference service, the method proceeds from step E87 to step El and preferably, the unit UC controls the broadcast of a text message or voice signaling that the mobile receiver RE is out of network coverage for the current service which encourages the user to change service by means of the remote control TC.

Claims (1)

  A method of transferring multiplex signal (TS) in a mobile digital television receiver (RE) tuned to a first carrier frequency of a reference multiplex signal supporting a first table (NIT) associating identifiers (TSid) of a plurality of multiplex signals (TS) to test carrier frequency lists and a second table (PMT) defining components of a reference service consumed in the receiver and supported by the reference multiplex signal, characterized in that it comprises a tuning (E82) of the receiver at a test frequency and according to modulation characteristics read in the first table (NIT) when at least one transfer parameter (SYNC, SNR, BER, UNC) evaluated sequentially relative to the signal reference multiplex (TS) modulating the first frequency does not satisfy (E7) a predetermined condition, an evaluation (E83) of the transfer parameter for the multiplex signal modulating the test frequency, and a replacement (E21) of packet identifiers (Pid) relating to reference service components in the reference multiplex signal (TS) modulating the first frequency, by those read in the second table (PMT) extracted from the reference multiplex signal modulating the test frequency when the evaluated transfer parameter satisfies the predetermined condition in order to configure decoders (D1-D3).   2 - Process according to claim 1, wherein the transfer parameter is relative to a synchronization (SYNC) of the receiver for which the predetermined condition is satisfied when the receiver has acquired correct first bytes detected in a predetermined number of consecutive packets in the reference multiplex signal (TS).   The method of claim 1 or 2, wherein the transfer parameter is a signal-to-noise ratio (SNR) for which the predetermined condition is satisfied when it is greater than a minimum signal-to-noise ratio.   The method according to any one of claims 1 to 3, wherein the transfer parameter is a bit error rate (BER) for which the predetermined condition is satisfied when it is less than an error rate. maximum binary.   A method according to any one of claims 1 to 4, wherein the transfer parameter is a number (UNC) of uncorrected blocks of predetermined length after decoding in the reference multiplex signal (TS) for which the predetermined condition is satisfied when it is less than a maximum number of uncorrected blocks.   6. Process according to any one of claims 1 to 5, comprising in conjunction with the sequential evaluation (E7) of said at least one transfer parameter (SYNC, SNR, BER, UNC) relative to the reference multiplex signal modulating the first frequency, a comparison (E7) of the identifier (TSid) of the reference multiplex signal stored in the mobile receiver (RE) to the multiplex signal identifier in the packets of the multiplex signal (TS) received by the mobile receiver (RE ) to perform a tuning (E82) of the mobile receiver at the test frequency and an evaluation (E83) of the transfer parameter for the reference multiplex signal modulating the test frequency when the compared identifiers are different.   Io 7 - Process according to any one of claims 1 to 6, wherein the evaluation (E83) of said at least one transfer parameter (SYNC, SNR, BER, UNC) is iterated (E82) several times for the frequency as long as the evaluated transfer parameter does not satisfy the predetermined condition.   8 - Process according to any one of claims 1 to 7, wherein the evaluation (E83) of said at least one transfer parameter (SYNC, SNR, BER, UNC) is iterated (E84, E85) several times for each of several test frequencies read in the first table (NIT) as the evaluated transfer parameter does not satisfy the predetermined condition.   9 - Process according to any one of claims 1 to 8, wherein the evaluation (E83) of said at least transfer parameter (SYNC, SNR, BER, UNC) is iterated (E86) several times for the multiplex signal of reference (TS) with several associated test frequencies as long as the evaluated transfer parameter does not satisfy the predetermined condition.   Method according to any one of claims 1 to 9, wherein said at least one transfer parameter (SYNC, SNR, BER, UNC) is evaluated (E85, E86, E87) for at least one test multiplex signal of which identifier (TSid) is included in the first table (NIT) and is associated with the identifier (SID) of the reference service in a third table (SDT) extracted from the test multiplex signal and describing services offered by the signal test multiplex when the evaluated transfer parameter for the reference multiplex signal does not satisfy the predetermined condition.   11 - Method according to any one of claims 1 to 10, comprising an update (E3, E5) of at least the first table (NIT) in the receiver while trying to extract the first table in the reference multiplex signal ( TS) for a predetermined predetermined period of time.   12 - Process according to any one of claims 1 to 11, comprising a replacement (E21) of packet identifiers (Pid) relating to components of the reference service in the reference multiplex signal (TS) modulating the first frequency , by those provided by a specific application external to the transfer.