FR2757338A1 - ADAPTATION BETWEEN UNIDIRECTIONAL PAGING NETWORKS - Google Patents

Abstract

A first one-way paging network already in operation (DN1), and a second network (DN2) to be set up have base stations (BS1, BS2) periodically transmitting in quasi-synchronism batches of messages to mobile receivers (REC). Each mobile receiver monitors in standby position a respective batch in a sub-sequence of predetermined duration TS. In order to avoid the designer of the second network having recourse to "owner" interfaces in the first network, the networks are connected through an adaptor (AD) connected to a predetermined base station (ABS) in the first network (DN1) and imposing a batch transit time of about k.TS, with k >/= 1. In the adaptor, a delay equal to the difference of the transit time and of the batch processing time in the adaptor is imposed on the batches.

Description

Adaptation between paging networks
unidirectional
The present invention relates to the connection of a first unidirectional paging distribution network in a first coverage area to a second unidirectional paging distribution network to be located in a second coverage area.

 A unidirectional paging network broadcasting messages over a first coverage area essentially comprises two parts. A first fixed switching and maintenance part is connected to the telecommunications networks accessible to requesting terminals and manages the routing of messages transmitted by requesting users to mobile receivers. A second fixed part constitutes a message distribution network between the first part and base stations distributed in the coverage area and transmitting messages in near synchronism to the mobile receivers.

 When the broadcast area of the first paging network already in operation must be extended to a second coverage area which may be different from the first area, or which may be confused with the first area to increase traffic there, by means of '' a second paging network of different technology, this should be directly connected to the first part of the first network. The interfaces in this first part are "proprietary" interfaces which are specific to the designer of the second network and require specific adaptation by the designer of the second network. This specific adaptation would limit the installation of second networks only in relation to the first determined networks and therefore increase the cost of the second networks.

 The present invention aims to connect first and second unidirectional paging networks of different technologies to allow the designer of the second network to connect it to any first network insofar as the two networks meet standards imposed at the level of radio interface between base stations and mobile receivers.

To this end, a method for connecting a first unidirectional paging network to a second unidirectional paging network both having base stations transmitting batches of messages in quasi-synchronous fashion to mobile receivers, each mobile receiver monitoring in the state watch a batch having a respective rank in a sub-sequence, a cycle of duration
TC comprising NS sub-sequences of predetermined duration TS, is characterized in that the networks are connected through an adapter which is connected to a predetermined base station in the first network and which imposes a transit time on the batches transmitted by the station of predetermined base equal to approximately k.TS, k being an integer at least equal to 1.

 The adapter is thus connected at the radio interface of the first network. The radio interface is "open" to all network designers since it must satisfy in detail a standard prescribed at least at European level.

 The transit time of the batches through the adapter ensures the quasi-synchronism of the base stations of the networks, and the monitoring of the respective batches by the mobile receivers whether they are in the coverage area of the first or of the second network.

 The transit time can be equal to approximately m.TC, m being an integer at least equal to 1, which still ensures the research of the respective lots by the mobile receivers in spite of the delay due to the crossing of the adapter by the lots .

 The input port of the adapter is preferably connected to the bus between the controller and the transmitter included in the predetermined base station, the transmitter having an antenna output connected to a load preventing it from transmitting. Such a link between adapter and predetermined base station saves the addition of a radio receiver to the antenna output of the station and guarantees a better quality of information transmission.

 The invention also relates to an adapter for implementing the method for linking the above networks. The adapter is characterized in that it comprises a means for processing the batches of message transmitted by the predetermined base station, and a means for imposing a delay in the batches equal to the difference between the transit time and a transmission time. batch processing in the means for processing.

The means for processing are provided essentially for retransmitting "batches" compatible at least in terms of the information they contain with the second paging network. As will be seen below, depending on the content of batches transmitted by the predetermined base station, the means for processing can comprise
a means for deinterleaving the messages contained in the batches transmitted by the predetermined base station; and or
- means for extracting error correction control bits in code words contained in parts other than a synchronization part in batches; and or
a means for modifying a sequence number i contained in each batch into a number j such that
j = (i + k) modulo NS; and or
a means for modifying a cycle number contained in each batch by incrementing it by at least one unit when i + k 2 NS, i being the number of the sub-sequence containing the batch; and or
- a means of modifying time-stamping information contained in each batch by adding to it the transit time.

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 known one-way paging system relating to a predetermined coverage area
FIG. 2 is a diagram showing a sequence of cycles each composed of twelve sub-sequences of sixteen batches transmitted at the level of a radio interface in a known paging distribution network;
- Figure 3 is a diagram showing in detail the known structure of the parts of a batch of sequences;
- Figure 4 is a block diagram showing the connection of a second unidirectional paging distribution network to the first unidirectional paging distribution network via a network adapter according to the invention
- Figure 5 is a functional block diagram of the network adapter;
- Figure 6 is a diagram showing the time difference between sub-sequences from the first network and corresponding sub-sequences transmitted in the second network according to a first embodiment;
- Figure 7 is a diagram showing the time difference between sub-sequences from the first network and corresponding sub-sequences transmitted in the second network according to a first embodiment
- Figure 8 is a diagram showing a time offset imposed by the adapter according to first and second variants of the invention; and
- Figure 9 is a diagram showing a time offset imposed by the adapter according to a third variant of the invention.

In order to better understand the invention, the main characteristics of a unidirectional paging system (in English: paging system) which are particularly concerned with the invention are recalled. The paging system is of the ERMES (European Radio) type
Message System) complies with ETS 300 133 standards published in 1992 by ETSI (European
Telecommunications Standard Institute), Sophia
Antipolis, France.

 The paging system is divided into several paging areas provided respectively by one-way paging telecommunications networks. Figure 1 schematically shows such a paging network covering a predetermined coverage area, for example approximately a French region such as the Ile de France.

A unidirectional paging network is organized around a PNC (Paging) network controller
Network Controller) and at least one PAC (Paging Area Controller) coverage area controller. The PNC controller manages three interfaces, an I4 interface with PNC network controllers from other operators, a dual I5 / I6 interface with telecommunications networks accessible to users, such as the public PSTN telephone network, and an I3 interface with the PAC coverage area controller.

The PNC network controller is analogous to a switching center and ensures dialogue with requesting users so as to record messages and transmit them respectively to the PAC controller of the predetermined coverage area, and to the network controllers of others. coverage areas. The network controller
PNC manages message traffic by consulting databases on functional, subscription and geographic characteristics of REC mobile receivers. The network controller also exchanges information, in particular on quality measurements, alarms and traffic statistics, with an OMC (Operation and
Maintenance Center).

 The PAC coverage area controller queues the messages intended for the predetermined coverage area so as to format them into frames transmitted to the base stations through an interface I2. Data is exchanged in accordance with the I2 interface between the PAC controller and BSC base stations through a DN distribution network. The DN network is located between a management and operating site comprising the PNC and PAC controllers and transmission sites where the BS (Base Station) stations are located, appropriately distributed in the coverage area where REC portable receivers (pagers) of requested users can move. The distribution network may be a satellite telecommunications network or a packet telecommunications network or a network of dedicated links.

 The coverage areas are associated respectively with channel frequencies, at the rate of one or more frequencies per area depending on whether the traffic is low or high in the area. The frequencies between two adjacent zones can be different, as in a radio-cellular network, although two adjacent zones can share temporal sub-sequences of cycles of a common frequency channel, as specified below.

 When a requesting user wishes to transmit a message to a requested mobile user, the number of the requested user is transmitted by the terminal of the requesting user which can be a conventional telephone set or else a videotex terminal or any access terminal to the PNC network controller so as to communicate either vocally or via a screen with the PNC network controller serving the terminal of the requesting user. The PNC controller converts the message into a message compatible with ETS standards and accesses a database containing information on the type of receiver of the requested user as well as on the characteristics of the messages to be sent to him, if applicable. if necessary by means of the network controller serving the coverage area where the requested user is located. Then the PNC controller which is responsible for the distribution of the message in the coverage area where the requested user is located composes one or more frames containing a radio identity code of the receiver so as to transmit the message or the successive parts of that -this via the PAC controller to the BS base stations.

 The interface I2 between the coverage area controller PAC and the base stations BS is bidirectional in order to transmit from the controller to the base stations the messages intended for the mobile receivers REC and information related to the traffic and to the maintenance of the stations base to the PAC controller.

 At the radio interface I1 between the base stations BS and the mobile receivers REC, the messages are formatted in four subdivisions, first a sequence, then a cycle, a sub-sequence and finally a batch, as shown in FIG. 2. A sequence comprises sixty cycles each having a duration TC of one minute. A receiver monitors one or a few cycles in a sequence so as to reduce the consumption of batteries included in it. Each cycle is composed of NS = 5 sub-sequences SSO to SS4. Each sub-sequence has a duration TS of twelve seconds and is divided into sixteen batches denoted A to P. Each batch constitutes a unit of protocol data at the level of the radio interface I1 and comprises in a message part typically 154 words of 30-bit code, except for the last batch P which contains 190.

 The sequence time reference is universal time so that all active base stations transmit sub-sequences in synchronism to within 50 zs. Thus, each sequence begins exactly every hour and each cycle begins exactly every minute.

 As shown in more detail in Figure 3, each batch is made up of four parts, a synchronization part SP and a part of SIP system information which have a fixed length, and an address part AP and a message part MPs that have variable length.

The synchronization part SP comprises two words at 30 bits, a preamble PR for the synchronization of the bits and a synchronization word
SYN for batch synchronization.

 The SIP system information part comprises two words containing in addition to a country code, an operator code and a coverage area code, in particular information on the batch rank, that is to say the batch number to 4-bit BN in the respective subsequence, the 3-bit subsequence number SSN in the respective cycle, the 6-bit CN cycle number in the respective sequence, and an FSI frequency indicator among five of a frequency subset , each mobile receiver being associated with one of 16 frequency subsets. The system information part is terminated by an SSI additional system information word which is composed of the first four SSIT bits to indicate a type of time stamp information and the last fourteen SSIF bits to indicate time stamp information. corresponding to the selected type. When the SSIT bits are "0000", the additional SSIF information indicates in particular the local time from 0 to 24 with 5 bits and the day of the month from 1 to 31 with 5 bits. When the SSIT bits are "0001", the additional information indicates the day of the week with 3 bits, the month with 4 bits and the year with 7 bits.

The third part AP of a batch contains initial 18-bit addresses IA of the mobile receivers REC for which the messages, or the message portions, contained in the message part of the batch are intended. The AP address part is terminated by at least one end indicator APT (Address
Partition Terminator) which also serves as a fill code word.

 The message part MP comprises the messages proper separated by message delimiters. Each message begins with a header having a fixed length and comprising in particular the entire 22-bit local address of the requested receiver, the message number for this receiver, a bit indicating whether the receiver is in its home coverage area or no, and a variable information field including the type of message transmitted, for example tone or alphanumeric, and the long character of the message. The initial address includes the 18 most significant bits of the local address.

In each base station BS (FIG. 1), a controller BSC formats the messages transmitted in frames in the distribution network DN according to the batch format described above. The BSC controller adds the synchronization part to each frame
SP, the APT end indicator (s) and message delimiters. The controller BSC detects the message frames which are intended for the base station BS, and performs coding and interleaving of the code words before applying the batches thus formed to the radio interface I1 via a TM transmitter and AN transmitting antenna in the base station BS, to the mobile receivers REC.

A code word in one of the three parts of a batch comprises in practice eighteen bits of information and twelve control bits of a cyclic error corrector code whose generator polynomial is of the BCH code type. After coding, the code words only in the message part are grouped into blocks of nine words. Each block is interleaved so as to preserve the information during reception from errors due to the transmission between the transmitter and the mobile receivers.

 In the standby state, a mobile receiver "listens" only on a predetermined batch in a predetermined sequence. The message is contained in the message part of the predetermined batch, and if the message is long, it can be divided into subsequent batches of the sub-sequence, or even in other sub-sequences of the same cycle. If a message starts in one batch and is contained in the next batch, there is no message delimiter between the separate parts of the message. In the latter case, the number of bits remaining in the message to be transmitted is indicated in the header of the part of the message contained in the previous sub-sequence.

 With reference to FIG. 4, there is a first unidirectional paging distribution network DN1 which is served by the network controller PNC and the coverage area controller PAC and which serves several base stations BS1 each comprising a controller BSC1 and a TM1 transmitter as well as an AN1 antenna. The DN1 distribution network is considered to be already installed in a first predetermined coverage area.

 According to the objective of the invention, a second unidirectional paging distribution network DN2 must be located in a second predetermined coverage area distinct from the first area, such as one or more French regions, or merged with the first area if traffic in it must be increased. The second distribution network is allocated at least a second channel frequency which may be different from or equal to one of the first channel frequencies allocated to the first distribution network. The second DN2 distribution network is designed using a technology different from that of the first DN1 distribution network and transfers messages according to an I2 format and protocol different from those described above at the I2 interface in the first DN1 network. and defined by the designer of the second network. However, the radio transmission of messages by means of sequences of sixty minutes, cycles of one minute in each sequence, five sub-sequences SS0 to SS4 of twelve seconds in each cycle, and 16 batches in each sub-sequence is maintained. The DN2 distribution network also serves BN2 base stations, each comprising a BSC2 controller and a TM2 transmitter connected to an AN2 antenna.

According to the invention, the second distribution network DN2 is coupled to the first network DN1 via a predetermined base station
ABS included in the first network and an AD network adapter according to the invention. The role of the adapter mainly consists in synchronizing the second distribution network DN2 with the first distribution network DN1 and in extending the transmission of messages to the entire second coverage area via the first network.

The AD adapter does not disturb the operation of the first network since the message batches are picked up in an ABS base station of the first network.

 As shown in Figure 4, an input bus BE of the AD adapter is connected, not to the SAN antenna output of the ATM transmitter in the ABS base station, but to an intermediate interface bus I20 between the ABSC controller and the ATM transmitter in the ABS base station, which avoids the addition of a suitable reception circuit. More specifically, the input bus BE is connected to the unidirectional parallel part of the bus I20 which transmits data bits and a bit clock signal normally to the ATM transmitter, and is not connected to the bidirectional serial part of the I20 bus to send commands and parameters to the ATM transmitter and return alarms and status information from the latter through the ABSC controller to the PAC coverage area controller. The SAN antenna output is not connected to an antenna, but to a dummy load CH, typically a termination at 50 ohms.

The output SA of the adapter AD is in practice connected to a distribution network controller CRD of the second distribution network DN2 through an interface I2 specific to the designer of the second network
DN2.

 Referring now to FIG. 5, the network adapter AD comprises at the input BE a clock recovery circuit 1 and a batch detection circuit 2. The circuit 1 detects the preamble PR and the synchronization word SYN in each batch transmitted by the ABSC controller to recover a clock signal at the frequency of the bits and a clock signal at the frequency of the code words at 30 bits. The batch detection circuit 2 is controlled by the circuit 1 to extract the last three parts in each batch after recognition of the preamble PR and the synchronization word SYN.

 At the output of the detection circuit, only the detected message part MP is deinterleaved by blocks of nine message code words in a deinterleaver 3. The other two parts SIP and AP undergo a delay corresponding to the deinterlacing at output of the detection circuit 2 .

The detected SIP system information part and the AP address part and the message part
Deinterleaved MPs are decoded one after the other in an error correction decoder 4. The 12 control bits in each code word are removed. During the error correction decoding, the wrong code words are detected, but the information bits in these wrong words are not corrected. The APT end flags and message delimiters are also removed. In this way, the three-part batches leaving the decoder 4 are analogous to the information contained in the message frames transmitted to the base stations BS1 through the interface I2.

The decoded SIP system information part and AP address part and the message part
MP deinterleaved and decoded from each batch produced by circuits 2 to 4 are applied successively to a time compensation circuit 5.

 The batches received from the I20 interface of the ABS base station are retransmitted according to the same time order in the I2 interface of the DN2 distribution network without changing the useful content of the addresses and messages.

As already said, all the base stations BSC1 and BSC2 of the networks DN1 and DN2 must transmit in quasi-synchronism the subsequences SS0 to SS4 in each cycle. However, messages may be out of sync in the second distribution network
DN2 due to the processing of messages between the ABS base station in the first network and the BS2 base stations in the second network. A time offset of a few seconds, in practice 0 to 9 seconds, relative to a time reference of start of sub-sequence in the base stations is tolerated for the reception of messages in the base stations, this time offset corresponding to the data storage capacity to be transmitted from each base station controller.

 Typically, the quasi-synchronous transmissions from the base stations in the two networks DN1 and DN2 are such that the start of each of their cycles is fixed to within + 2 ms relative to the time reference, which is universal time, and therefore the start of each of their batches at + 50 ps.

This condition is imposed by the periodic reception of the predetermined batch having a respective rank in the sub-sequences to which each mobile receiver REP is assigned in the standby state.

Knowing that the processing of the batches between the ports BE and SA of the adapter AD of the invention confers a processing time TR, the batches in a subsequence SSi entering the adapter must be retransmitted in a subsequent subsequence SSj outgoing of the adapter, after a transit time greater than TR and equal to an integer multiple of the duration TS of the sub-sequences, as shown in Figure 6, where i and j are integers varying between 0 and 4 and j is greater than i + l modulo 5. The subsequence SSj can be included in the same sequence as the subsequence SSi, or in one of the following sequences.

The time compensation circuit 5 essentially comprises a delay means which imposes a delay RE on the batches, such that the transit time through the adapter AD is equal to
TR + RE z k.TS
where TS is the 12-second duration of a subsequence and k is an integer at least equal to 1, such that j = (i + k) modulo NS, where NS = 5 is the number of subsequences. The sign "approximately" means that the equality between the two members of the previous relation is true to within a few seconds, that is to say from 0 to 9 seconds, delay less than the duration of the sub-sequence, in agreement with the time offset for receiving messages at base stations.

 When a message is long and is distributed in several batches of the same sub-sequence or in several sub-sequences, the continuity of the message is preserved through the AD adapter thanks to the time offset k.TS. As shown in FIG. 7, for example a message MR distributed in the successive sub-sequences SSO and SS1 at the input RE of the adapter AD is further distributed in the same way in subsequent sub-sequences SS3 and SS4 at the output SA of the adapter, after a time difference of approximately k.TS = 3TS.

 Under these conditions, when a receiver REC recognizes its initial address in the address part AP of a batch, it classically monitors the message part MP of the batch for a duration appreciably less than TS, without the time offset provided by the adapter of the invention modifies the periodic monitoring of the batch.

When several frequencies are allocated to several coverage areas and / or several frequencies are allocated to the same coverage area with high traffic, the sub-sequences relating to two consecutive frequency channels are time-shifted according to the ETS standard 300 133. For example, If the following subsequence has as carrier frequency the channel frequency Ol
ABCDEFGHIJKLMNOP
the following subsequences are assigned to channel frequencies 03 and 05:
BCDEFGHIJKLMNOPA
CDEFGHIJKLMNOPAB.

 The time shift of a batch from one frequency to the next facilitates the channel search by a REC mobile receiver, and allows the receiver to monitor all the channels only during the duration of a sub-sequence, that is to say ie for 12 seconds.

 When the frequencies F1 and F2 allocated to the distribution networks DN1 and DN2 are different, the time difference of at least one batch duration would mean that the last and sixteenth batch of a sub-sequence is different; for example, the batch P is different from the batches A and B in the two subsequences above, the batch P being longer by 36 words of code than the other batches A with O. In order to preserve the same order of the batches in the frequencies passing through the AD adapter, and to avoid a longer or shorter batch than that expected, the frequency (or frequencies) "declared" in the second distribution system DN2 is the same as that in the first distribution network DN1 , i.e. PNC network controllers consider the coverage area covered by the DN1 and DN2 networks as a coverage area covered by the frequencies allocated to the DN1 network although the frequency (s) in the ABS base and therefore to the second DN2 network, the sub-sequences SS1, SS2 and SS (i + 1) are used in the channel F2, the sub-sequences SS2 to SS4 in the channel F1 can be attributed to other coverage areas. The transit time imposed by the network adapter AD is then equal to approximately k.TS with k 2 1, k being equal to 1 according to the example in FIG. 8.

According to a second variant also shown in FIG. 8, the first and second distribution networks share a common channel frequency. For example, the second network is initially assigned the sub-sequences SSO and SS1 in the first network, and the sub-sequence SS2 is not used in the first network. With a transit time of approximately k.TS = TS, the adapter moves the sub-sequences SSO and SS1 into the two sub-sequences SS1 and SS2 which are used by the second network
DN2, without disturbing the sub-sequences used by the first DN1 network.

 According to a third variant of the invention, a common frequency F1 = F2 is allocated to the distribution networks DN1 and DN2. According to the example shown in FIG. 9, the sub-sequences SSO and SS1 allocated in the network DN1 are assigned to the network DN2, and the other sub-sequences SS2, SS3 and SS4 also modulating the channel frequency F1 = F2 are assigned to the first DN1 network and / or to other coverage areas respectively. The SS2, SS3 and SS4 sub-sequences cannot be assigned to the second DN2 network. The transit time imposed by the network adapter AD is then equal to a cycle time TC, or more generally to m.TC where m is an integer at least equal to 1.

 Each batch without synchronization part leaving the time compensation circuit 5 is applied to an update circuit 6 to update the batch and more precisely the part of SIP system information shown in FIG. 3.

Updating each batch in circuit 6 is the main contribution in processing time
TR in the adapter.

In the SSN 3-bit subsequence number field, the number i of the incoming subsequence
SSi is replaced by the number j of the outgoing sub sequence SSj
j = (i + k) modulo NS, with NS = 5.

The CN cycle number in the SIP part of the SSi sub-sequence is incremented by at least one unit in the SSj sub-sequence when the sub-sequences
SSi and SSj belong to different cycles, that is to say when i + k 2 NS.

When the first four SSIT bits of the additional system information field are "0000" or "0001", the time stamp information
SSIF must be updated as a function of the transit time k.TS of the order of a few tens of seconds per minute imposed by the AD adapter on an incoming SSi sub-sequence containing time information near the end of an hour, or the end of a day (midnight), or the end of a month, or the end of a year. In other words, the previous timestamp information contained in the SSi sub-sequence must be modified by adding the transit time k.TS to it.

 More precisely for SSIT = "0000", when the local time available in the AD adapter is close to the end of an hour to the time difference k.TS near when entering the subsequence SSi, the "local time" information is incremented by a modulo 24 unit in the sub-sequence SSj; when the local time is near the end of the 24 hours to the nearest k.TS when entering the SSi sub-sequence, the "day of the month" information is incremented by one unit modulo the number of days in the current month in the SSj subsequence. For SSIT = "0001", when the local time is close to the end of a day to the nearest k.TS when entering the SSi sub-sequence, the "day of the week" information is changed to the next day in the SSj sequence; when the local time is near the end of a month to the nearest k.TS when entering the SSi sub-sequence, the "month" information is incremented by a modulo 12 unit in the sub-sequence SSj; when the local time is near the end of a year to the nearest k.TS when entering the subsequence SSi, the "year" information is incremented by one in the subsequence SSj.

 The batch update circuit 6 also corrects the time stamp information when the local time changes between summer and winter periods.

 The adapter AD finally comprises a message request formatting circuit 7 followed by a message transmission circuit 8. The circuit 7 introduces the corrected batches leaving the update circuit 6 in request primitives, called frames of message request (Request frame) conforming to the I2 interface, at the rate of one or more successive corrected batches per frame. Each frame includes a header preceding the batch field and a cyclic redundancy code (CRC) field succeeding the batch field and deducted therefrom; interleaving is performed by bit blocks on the batch field and the cyclic redundancy code field. The circuit 7 is for example a modem which transmits the message request frames to the CRD controller of the second distribution network DN2.

Claims (9)

 1 - Method for connecting a first unidirectional paging network (DN1) to a second unidirectional paging network (DN2) both having base stations (BS1, BS2) transmitting cyclically in batches of message batches (A to P) to mobile receivers (REC), each mobile receiver monitoring in the standby state a batch having a respective rank in a sub-sequence (SS0 to SS1), a cycle of duration TC comprising NS subsequences of predetermined duration TS,  characterized in that the networks (DN1, DN2) are connected through an adapter (AD) which is connected to a predetermined base station (ABS) in the first network (DN1) and which imposes a transit time on the batches transmitted by the predetermined base station equal to approximately k.TS, k being an integer at least equal to 1.  2 - Process according to claim 1, according to which the transit time is equal to approximately m.TC, m being an integer at least equal to 1.  3 - Method according to claim 1 or 2, according to which an input port (BE) of the adapter (AD) is connected to a bus (I20) between a controller (ABSC) and a transmitter (ATM) included in the predetermined base station (ABS), the transmitter having an antenna output (SAN) connected to a load preventing it from transmitting (CH).  4 - Adapter for implementing the method according to any one of claims 1 to 3, characterized in that it comprises means (2, 3, 4, 6, 7) for processing the message batches (A to P) transmitted by the predetermined base station (ABS), and means (5) for imposing a delay (RE) on the batches equal to the difference of the transit time (k.TS) and a processing time of batch (TR) in the means for processing.  5 - An adapter according to claim 4, wherein the means for processing comprises means (3) for deinterleaving the messages (MP) contained in the batches transmitted by the predetermined base station (ABS).  6 - Adapter according to claim 4 or 5, wherein the means for processing comprises means (4) for extracting error correction check bits in code words contained in parts (SIP, AP, MP) other than a synchronization part (SP) in batches.  7 - An adapter according to any one of claims 4 to 6, wherein the means for processing comprises means (6) for modifying a sub-sequence number i (SSN) contained in each batch into a number j such that  j = (i + k) modulo NS.  8 - Adapter according to any one of claims 4 to 7, wherein the means for processing comprises means (6) for modifying a cycle number (CN) contained in each batch by incrementing it by at least one unit when i + k 2 NS, i being the number of the sub-sequence containing the lot.  9 - Adapter according to any one of claims 4 to 8, wherein the means for processing comprises means (6) for modifying time stamping information (SSIF) contained in each batch by adding thereto the time of transit (k.TS).