FR2787281A1 - Base station/peripheral information communication technique having information time length divided and transmission active/passive sequence having detection phase interrupting transmission/introducing delay when other stations detected. - Google Patents

Abstract

The information communication technique transfers information from a base station to a number of peripheral stations. The reservation of information time is divided up into lengths and transmitted over time intervals. The access request for information has a real attribution sequence to the peripheral communication. Each arbitration sequence has an active and passive part. A detection phase (E5) finds when another station is transmitting at the same time. If an interruption is found (E6) then a delay is introduced and the actual transmission carried out on the next cycle, otherwise the active arbitration sequence is sent.

Description

The present invention relates to a method of communicating information

  by radio frequencies between a base communication station and several peripheral communication stations and also relates to a base communication station, a peripheral communication station, an information processing device and a communication network

communication of information.

  Radio frequency information communication networks are known which include a generally fixed base communication station and several peripheral communication stations

  distant from each other as well as from the base station.

  In such communication networks, the base station allocates to the various peripheral stations the different radio communication channels to be used during their future information transmissions as well as the

  corresponding time windows.

  In order for a peripheral station to be able to transmit information to the base station on a given radio communication channel for a determined period of time, it is necessary for said peripheral station to signal it before said base station by a method called "reservation", according to which the peripheral station transmits to the base station a request for access to said radio communication channel in order to reserve the latter for its

next communication.

  Document US Pat. No. 4,583,217 discloses a method of reserving access to a radio communication channel in a network of the type previously described which consists, firstly, in dividing the time allocated to a so-called reservation phase into one plurality of consecutive time intervals and, secondly, to transmit from peripheral stations which want to reserve access to said radio communication channel a so-called access request which takes the form of energy pulses. The pulses are coded so that the codes of all these stations

are orthogonal.

  Thus, this allows the base communication station to differentiate the access requests from the different communication stations

peripherals between them.

  In the event of a collision, that is to say when several peripheral communication stations simultaneously transmit their access requests, only the peripheral station whose energy pulses are received by the base station with the highest intensity is recognized by said base station and will therefore see its request for access to a radio communication channel accepted. The base station will therefore allocate a time window to the

  peripheral station selected for its next transmission of information.

  However, the other peripheral stations will not be informed of the acceptance of their request for access to a radio communication channel until later, during a so-called signaling phase, during which the base station transmits to the stations. devices a message affecting them

  a transmission time window.

  The present invention aims to remedy this drawback and proposes for this purpose a method of communicating information between a base communication station and a plurality of peripheral communication stations on at least one radio communication channel, comprising a reservation phase access to said radio communication channel by said peripheral communication stations, said method comprising the following steps: -dividing the duration of said reservation phase into a plurality of consecutive time intervals, [III-broadcast, during '' the same time interval, by each of said peripheral communication stations of a so-called access request, characterized in that said access request takes the form of a so-called arbitration sequence specific to said peripheral communication station corresponding, each so-called arbitration sequence consisting of a series of so-called active and passive parts s, and in that said method further comprises the following steps: -detection, during said same time interval, by at least one of said peripheral communication stations having at a given time a passive part in its arbitration sequence of the nature of the part of the arbitration sequences transmitted by other peripheral communication stations at the same time, interruption of the transmission of the arbitration sequence of said at least one peripheral communication station having detected an active part in the arbitration sequence of another peripheral communication station. Thus, a peripheral station seeing the transmission of its interrupted arbitration sequence knows, therefore, that its request for access to the transmission channel

  radio communication was not immediately accepted.

  In addition, the method according to the invention makes it possible to carry out in a simple manner an arbitration between the different access requests originating from the different peripheral stations in order to prevent them from simultaneously issuing their requests for the purpose of booking access to the

radio communication.

  In addition, the recognition of the active and passive parts of the arbitration sequences by the base communication station does not require a step of decoding the access requests, which brings simplification and

time saving.

  Furthermore, the fact that the arbitration sequence of a peripheral station is interrupted makes it possible to reduce the information rate

  transmitted by it and therefore its energy consumption.

  According to one characteristic, the method also comprises, during the following time interval, a step of retransmission of an arbitration sequence by said at least one peripheral communication station whose

  the transmission of the arbitration sequence was previously interrupted.

  Thus, this characteristic makes it possible to increase the efficiency of the method according to the invention since several requests for access to the radio communication channel can be transmitted by the same peripheral communication station during the same reservation phase without the need, as the prior art previously provided for, to wait for the phase

  next reservation to transmit requests.

  The arbitration sequence consists for example of a series of bits in which a bit of a first nature corresponds to the so-called active part

  and the second nature bit corresponds to the so-called passive part.

  Prior to the transmission of an arbitration sequence specific to each peripheral communication station, said method comprises a step of generating either a random sequence of active and passive parts constituting said arbitration sequence or of a determined series of active and passive parts constituting said arbitration sequence is again, on the one hand, a determined series of active and passive parts and, on the other hand, a random series of active and passive parts constituting said arbitration sequence. Generating a random sequence of active and passive games ensures that not all arbitration sequences will transmit

  part of the same nature simultaneously.

  It may be advantageous to fix at least part of the arbitration sequence (s) in order to establish priorities between the different stations.

peripheral communication.

  According to one characteristic, the arbitration sequence specific to each peripheral communication station comprises at least one bit of

  confirmation at the end of the said arbitration sequence.

  This makes it possible to confirm to the base communication station that the arbitration sequence of the corresponding peripheral communication station has come to an end without the latter having simultaneously detected other peripheral communication stations desiring

  reserve access to the radio communication channel.

  This characteristic is advantageous insofar as the appearance of a parasitic energy pulse can cause the interruption of one or more arbitration sequences originating from peripheral stations which are, at the same time, in phase of detection of any other arbitration sequences and thus allow the base communication station to allocate a time window to a peripheral communication station

that does not exist.

  Consequently, the absence of a confirmation bit at the end of an arbitration sequence prevents the base communication station from reserving

  a time window which would subsequently remain unused.

  According to one characteristic, the method also includes a step of detection and reception of the arbitration sequences transmitted by the peripheral communication stations as well as of control, by said base communication station, of the fact that an arbitration sequence d 'a peripheral communication station has come to an end without interruption. When the arbitration sequence of a peripheral communication station has ended without interruption, the latter therefore knows that its request for access to the radio communication channel has been accepted and that a time window is allocated to it for the purpose of his future communication

  information to the base station.

  Thus, the reservation of access to the radio communication channel for all of the peripheral communication stations is carried out more quickly than in the reservation method described in the document of the prior art where only an access request is admitted. during each phase

of reservation.

  Furthermore, the step of checking that an arbitration sequence of a peripheral communication station has come to an end without interruption may consist in detecting the presence of a confirmation bit

  at the end of the said arbitration sequence.

  According to another characteristic, the method comprises a step of interrupting the reservation phase when no arbitration sequence has been received by said base station during the whole of a time interval. According to another characteristic, the duration of the reservation phase is flexible, for example, depending on the number of stations.

peripheral communication.

  Therefore, it is not necessary to provide a recording phase for new peripheral communication stations which wish to communicate information with the communication station.

basic.

  According to one characteristic, the method comprises a signaling phase consecutive to the reservation phase and comprising a step of transmission by said basic communication station of a message to the peripheral communication station, the request for access to the communication channel.

  radio communication was accepted.

  The message may include the arbitration sequence specific to the said

  peripheral communication station which advantageously allows this

  to immediately recognize the message intended for it.

  The present invention also relates to a method of communicating information between a peripheral communication station and a base communication station during a phase called reservation of access to at least one radio communication channel by said peripheral communication station, said reservation phase having a duration which is divided into a plurality of consecutive time intervals, said method comprising a step of transmission, by said peripheral communication station, of a so-called access request, during a time interval, characterized in that said access request takes the form of a sequence called arbitration specific to said peripheral communication station IrIf I and which consists of a series of so-called active parts and passive, and in that said method further comprises the following steps: -detection, during said same time interval, by said communication station peripheral device which presents at a given moment a passive part in its arbitration sequence of the nature of the part of the arbitration sequences transmitted by other peripheral communication stations at the same instant, -interruption of the transmission of the sequence of the peripheral communication station having detected an active part in the

  arbitration sequence of another peripheral communication station.

  The present invention further relates to a method of communicating information between a base communication station and a plurality of peripheral communication stations on at least one radio communication channel, comprising a phase of reserving access to said communication channel radio during which said peripheral communication stations wishing to reserve access to said radio communication channel transmit a so-called access request, said method comprising a step of dividing the duration of said reservation phase into a plurality of time intervals consecutive, characterized in that said method further comprises, on the one hand, a step of detecting and receiving access requests taking the form of arbitration sequences and transmitted, during the same time interval, by said peripheral communication stations and, on the other hand, control the fact that an arbitration sequence of a station peripheral communication has come to an end without being

  interrupted by the transmission of other arbitration sequences.

  The present invention also relates to a peripheral communication station capable of transmitting on at least one radio communication channel information to a remote base communication station which itself communicates with a plurality of other peripheral communication stations, said communication station on the one hand, prior to this transmission, before reserving access to said communication channel with said base communication station during a so-called reservation phase which is divided into a plurality of consecutive time intervals and, d secondly, comprising: means for transmitting an access request during a time interval, characterized in that said access request takes the form of a so-called arbitration sequence specific to said peripheral communication station which consists of a series of so-called active and passive parts, and in that said communication station peripheral also includes: -means of detection, during said same time interval, of the nature of the portion of the arbitration sequences transmitted by other peripheral communication stations at the same time, -means of interrupting the transmission of its own arbitration sequence, during the same time interval, when a passive party appears in its own arbitration sequence and an active party has been detected at the same time in the arbitration sequence of a other station

peripheral communication.

  The present invention further relates to a base communication station capable of communicating with a plurality of peripheral communication stations which must, before transmitting information on a radio communication channel, reserve access to said communication channel from said base communication station during a so-called reservation phase, said base communication station comprising means for dividing the duration of said reservation phase into a plurality of consecutive time intervals, said peripheral stations wanting to reserve a access to said radio communication channel transmitting a so-called access request during the same time interval, characterized in that said base communication station comprises means, on the one hand, of detection and reception of said requests for access taking the form of arbitration sequences and issued, during the same time interval, by lesdi your peripheral communication stations and, on the other hand, to control the fact that an arbitration sequence of a communication station! '. i 1 peripheral has come to an end without being interrupted by the transmission

other arbitration sequences.

  The present invention also relates to: an information processing device, characterized in that it comprises a peripheral communication station as mentioned above; -an information processing device, characterized in that it

  includes a base communication station as mentioned above

  above. The invention also relates to an information communication network which comprises a plurality of information processing devices each comprising a peripheral communication station as mentioned above and an information processing device

  including a base communication station as mentioned above

above.

  The invention further relates to a communication network which comprises a plurality of peripheral communication stations and a

  base communication station as set out above.

  According to one characteristic, at least some of said communication stations of the information communication network are associated with

  at least one information processing device.

  According to another characteristic, the communication station of

  base is associated with at least one information processing device.

  The aforementioned information processing devices can take the form of a computer, a printer, a fax machine, a scanner, a digital camera or even a digital camera. The invention also relates to a means of storing information readable by a computer or a processor containing instructions of a computer program, characterized in that it allows the implementation of the communication method according to the invention such as

briefly outlined above.

  The invention further relates to a means of storing information readable by a computer or a processor containing data originating from the implementation of the communication method according to

  the invention as briefly set out above.

  It should be noted that these storage means can be

  partially or completely removable.

  The advantages and characteristics of the information communication method between a peripheral communication station and a base communication station, of the information communication method between a base communication station and a plurality of peripheral communication stations, of the peripheral communication station, of the base communication station, of the processing devices, of the communication network and of information storage means being the same as those described above concerning the method according to the invention, they do not

will not be recalled here.

  Other features and advantages will become apparent during the

  description which follows, given solely by way of example and made in

  reference to the accompanying drawings in which: - Figure 1 shows a schematic view of an information communication network according to the invention; - Figure 2 schematically illustrates the different phases of a communication cycle, the division of the reservation phase into deltaT time intervals, the transmission and interruption of arbitration sequences according to the method of the invention ; - Figure 3 shows a block diagram of a base communication station; - Figure 4 shows a block diagram of a peripheral communication station; - Figure 5 is a schematic representation in the form of blocks illustrating the main functions performed by the central unit 18 of the base station - Figure 6 is a schematic representation in the form of blocks illustrating the main functions performed by the central unit 30 of the peripheral station; - Figure 7 shows an information communication algorithm from a peripheral communication station to a base communication station during the reservation phase; - Figure 8 shows a peripheral information communication algorithm from the base communication station to a peripheral communication station during the reservation phase - Figures 9 and 10 show alternative embodiments

  respective block diagrams of Figures 3 and 4.

  As shown in FIG. 1 and designated by the reference noted 10, a communication network according to the invention, for example a centralized communication network, comprises a base communication station 12 and several communication stations called peripheral

  SM1, SM2, ..., SM (N-1), SMN which are independent of each other.

  In the embodiment shown in FIG. 1, each peripheral communication station SM1, SM2, ..., SM (N-1), SMN is connected to an information processing device T1, T2, ..., .TN by a data bus bl, b2, ..., bN and the base station 12 is also connected to a

  processing of TO information by a data bus bO.

  The information processing device associated with each peripheral communication station and with the base station can take the form, for example, of a computer, a printer, a fax machine, a scanner,

  a digital camera or even a digital camera.

  The communication network 10 operates according to the principle of radio frequency communication between the base station 12 and the peripheral stations SM1, SM2, ..., SM (N-1), SMN on one or more channels of

radio communication.

  Time is divided into communication cycles such as by

  example that shown in Figure 2.

  This cycle has four phases: a first so-called signaling phase during which the base communication station 12 addresses the peripheral stations SM1, SM2, ... SM (N-1), SMN, or at least to certain '' between them, a message informing them each, on the one hand, that a time window has been allocated to them on a given radio communication channel with a view to their next transmission of information intended for said base communication station and , on the other hand, the characteristics of this window (duration of the windows and instant of the start of their opening); a second phase known as downlink communication which is dedicated to information communications from the base communication station 12 to the peripheral stations SM1, SM2, ..., SM (N-1), SMN; a third so-called upward communication phase which is reserved for information communications from peripheral stations SM1, SM2, ..., SM (N-1), SMN to the base communication station 12; -a fourth and final so-called reservation phase during

  which each of the peripheral communication stations SM1, SM2, ...

  SM (N-1), SMN wishing to communicate information to the base communication station during the next upward communication phase of the following communication cycle must first signal to said base communication station that it wants to reserve access to a radio communication channel, this reservation being made by transmitting a

  so-called access request to the base communication station.

  To communicate with each other, the base station and the peripheral stations use a communication protocol called MAC ("Medium Access Control" in English terminology) and which will be briefly described later. It should however be noted that this protocol controls the different

  phases of the communication cycle mentioned above.

  Before explaining in more detail the mechanism for reserving access to a radio communication channel by several peripheral communication stations SM1, SM2, ..., SM (N-1), SMN, it is necessary to describe the structure the base communication station and said stations

communication devices.

  As shown in FIG. 3, the base communication station 12 is connected by the data bus bO to the information processing device TO which is for example here a computer. The base communication station includes a ROM memory 14 and a RAM memory 16 which serves as a buffer memory, for example for storing information in the form of data frames coming, for example, from the TO device and intended to be transmitted on a radio communication channel. This RAM 16 can also be used to store the data frames received by a radio communication channel coming from the peripheral communication stations. The memories 14 and 16 have other functions which will be described later. Thereafter, we will call "register" any part of one of

these memories of variable size.

  Furthermore, it should be noted that the register 16f of the memory 16 contains a number of data frames I represented by the variable "Frame O to 1" and which are intended to be transmitted during a phase of

downlink communication.

  The base communication station also includes a central unit 18 which is, for example, a microcontroller, a modem interface, a conventional radio module 22 used to format the information before it is transmitted (digital / analog conversion,

  amplification, filtering ...) and a radio antenna 24.

  The information processing device TO is connected to the base station 12 by the data bus bO. The memories ROM 14, RAM 16

  and the central unit 18 are connected to a data bus bO1.

  The ROM memory 14 can for example be a “flash” type memory and contain different programs which will be loaded into the unit

central 18.

  The radio module 22 and the modem interface 20 are connected by a

b02 data bus.

  As shown in FIG. 4, each peripheral communication station SMi, i = 1, ..., N, also includes a ROM memory 26, a RAM memory 28, a central unit 30, a modem interface 32, a module

radio 34 and a radio antenna 36.

  The ROM memory 26 can for example be a “flash” type memory and contain the various programs which will be loaded into the unit

central 30.

  The memories, the modem interface, the radio module and the radio antenna of the peripheral communication station SMi exercise the same functions as the corresponding elements of the communication station of

base 12.

  The memories 26 and 28 have other functions which will be described later. The term "register" mentioned above will also be

  used in connection with memories 26 and 28 and retains the same meaning.

  An information processing device Ti, i = 1, .., N, is connected to

  the peripheral communication station SMi via a bi data bus. The memories ROM 26, RAM 28 and the central unit 30 are connected to a

  bil data bus and radio module 34 and modem interface

  32 are connected by a bi2 data bus.

  The central unit 18 of the base communication station brings together several functionalities which allow the transmission and reception of data frames as well as the management of the communication cycle and in particular the management of the time allocated to each phase of said phase.

communication cycle.

  These functionalities are ensured by the layers of the MAC communication protocol mentioned above which are contained in the ROM memory 14 and loaded into the central unit 18. For more information concerning this protocol, the person skilled in the art can refer to the document. EP

0 483 546.

  According to this protocol identified by the reference noted MACSB in FIG. 5 and whose main functions are illustrated in this figure, the "Transmission of a data frame" function identified by the reference TSB consists in formatting the data frames which must be transmitted on a

  radio communication channel to a peripheral communication station.

  These frames can be information frames from the

  associated TO information processing device or control frames.

  Control frames have several functions such as network reset requests, acknowledgment of data frames, the exchange of information concerning the configuration of each communication station ... The formatting of a frame includes the addition of a header which contains for example information concerning the number of the frame, the

  source and destination addresses.

  When the frames are thus formatted, the "Transmission of a frame" function TSB waits for the transmission order coming from the "Communication cycle management" function identified by the reference GCSB in FIG. 5 to transmit said frames to one or more several stations

  peripheral communication by requesting their modem interface 32.

  The "Reception of a frame" function identified by the RSB reference in FIG. 5 is activated when the modem interface 20 signals via the "Detection" function, identified by the DSB reference in this same figure. information on the radio communication channel used. This RSB function decodes this information by analyzing the header of the frame: if the destination address of the frame corresponds to the address identifying the base station 12, then the latter analyzes the frame and, depending on whether this frame is an information or control frame, it transmits it to the information processing device TO or else it analyzes its content and transmits the information to the "Communication cycle management" function GCSB. The "Detection" DSB function signals the presence of information on the radio communication channel used by the peripheral communication stations SM1, SM2, ..., SM (N-1), SMN by means of the modem interface 20

  which detects a power greater than the noise level on said channel.

  During the upward communication phase, the DSB function signals the arrival of frames from the peripheral communication stations. The GCSB function fixes the duration of each of the phases of the communication cycle illustrated in FIG. 2. The duration of the signaling and downward communication phases vary according to the amount of information that the

  base station must communicate with peripheral stations.

  During the signaling phase, the GCSB function indicates to the TSB function the information concerning the characteristics of the time windows reserved by the peripheral communication stations during the reservation phase of the previous communication cycle, this information having to be transmitted by the TSB function. who will prepare accordingly

  control frames and will then issue them.

  Depending on the number of time slots reserved, the GCSB function also defines the duration of the upward communication phase. The TSB, RSB, and DSB functions implemented by the central unit 18 of the base station 12 are similar to those used by the

  peripheral communication stations SM1, SM2, ..., SM (N-1), SMN.

  The functions "Transmission of a frame", "Reception of a frame" and "Detection" implemented by the central unit 30 of each peripheral communication station SMi are respectively referenced TSMi,

RSMi and DSMi in Figure 6.

  The "Communication cycle management" function of the communication protocol which is identified by the reference MACSMi in FIG. 6, referenced GCSMi in this figure, manages the different phases of the communication cycle.

  communication for the peripheral station SMi considered.

  During the signaling phase and during the time allocated by the GCSB function of the base station 12 to the downlink communication phase, the GCSMi function is placed on standby for reception of frames

  from the base station by activating the DSMi function.

  During the time allocated to the upward communication phase, the GCSMi function activates the TSMi function in order to prepare and transmit data frames according to the information received from the base station during the previous signaling phase and which relate to the characteristics of the time window that has been allocated to it. The communication method according to the invention will now be

  described with reference to Figures 2, 7 and 8.

  FIG. 7 represents an algorithm of the information communication method according to the invention seen from the side of a radio station.

SMi peripheral communication.

  This algorithm illustrates the reservation procedure provided for each peripheral station wishing to reserve access to a radio communication channel in order to communicate information to the base station 12 during the upward communication phase of the next cycle of

communication.

  The ROM memory 26 contains the instructions of the computer program, the algorithm of which is represented in FIG. 7 and which allows the implementation of the information communication method between a peripheral communication station SMi and the base station 12. This program

  called "Prog Périph" is stored in register 26a of memory 26.

  FIG. 8 represents an algorithm of the information communication method according to the invention seen from the side of the station.

  basic communication 12, during the reservation phase.

  The ROM memory 14 contains the instructions of the computer program, the algorithm of which is shown in FIG. 8 and which allows the implementation of the information communication method between the base station 12 and the peripheral communication stations SMi. This program called

  "Prog Base" is stored in register 14a of memory 14.

  When at least one data frame has been formatted by the TSMi function of the peripheral communication station as previously mentioned, it is stored in register 28a of the RAM memory 28 of said station (variable "Frame 0 to j"). When this frame is ready to be sent on the order of the GCSMi function, the algorithm represented in FIG. 7 is in step E1 and the variable "Frame ready" is positioned at the value "true" in the register 28b. Step E1 is followed by step E2 marking

  waiting for the start of the time window reservation phase.

  As indicated in FIG. 8 by step S1, the GCSB function of the base communication station 12 initializes the timers (called "timers" in Anglo-Saxon terminology) used for dividing the reservation phase into a plurality deltaT consecutive time intervals each with a fixed duration (variable "TdeltaT"). The GCSB function transmits this duration with the number of authorized time intervals (variable "NbdeltaT"), as well as the duration that was allocated during the reservation phase to the "Management of time intervals" function referenced

GSB in Figure 5.

  It should be noted that the variables "TdeltaT" and "NbdeltaT" are respectively stored in the registers 14b and 14c of the ROM memory 14 and are loaded, on initialization, in the registers 16a and 16b of the memory

RAM 16.

  A phase start message (step S2 of FIG. 8) is for example sent by the base communication station 12 to the peripheral communication stations SMi to inform them of the start of the phase of

  reservation and content of the variables "TdeltaT" and "NbdeltaT".

  It should be noted that other methods can be used

  to signal the start of the reservation phase.

  The GCSMi function will activate the "Detection" and "Time interval management" functions of the peripheral station SMi hereinafter referenced DSMi and GSMi in FIG. 6 which will manage the procedure for

  reservation of the time window for this station.

  When the base communication station 12 informs the peripheral station SMi of the start of the reservation phase, the GSMi function activates the "Generation of an arbitration sequence" function referenced GSAi in FIG. 6 and step E2 of l the algorithm of FIG. 7 is followed by step E3 during which the peripheral station generates and transmits a sequence

  to the base station.

  The GSMi function of the SMi peripheral station synchronizes the

  start of an arbitration sequence at the start of a deltaT time interval.

  An arbitration sequence constitutes a request for access to a radio communication channel which will be sent by the peripheral station SMi

wanting to reserve said access.

  An arbitration sequence is specific to a peripheral station and consists of a series of parts, some said to be active and others said to be passive. The arbitration sequence generated by the peripheral station is identified by the variable "SeqArb" and is stored in register 28c of memory 28. Thus, the GSAi function communicates to the modem interface 32 the orders relating to the active and passive parts of the arbitration sequence under consideration. When at a given instant the arbitration sequence of a peripheral station has a so-called passive part (steps E4 and E5 in FIG. 7), it is agreed that said peripheral station goes into detection or reception mode and informs the function DSMi to report any presence of others

  peripheral stations on the radio communication channel.

  By convention, the presence of other peripheral stations on the radio communication channel is detected when the arbitration sequence (s) of this (these) last (s) appear (s) at the same time

  a so-called active part (steps E4 and E7 of FIG. 7).

  The boolean variable "Detect" stored in the register 28d of the memory 28 is used to signal the fact that a presence is detected on the radio communication channel. When the DSMi function detects a presence

  on the channel, it sets this variable "Detect" to the value "true".

  When a given arbitration sequence has an active part, it is agreed that the peripheral station from which said sequence originates is then in transmission mode and transmits, for example, only one

  pulse at the carrier radio frequency.

  11i The presence of this active part in the arbitration sequence at this precise moment signals to the other peripheral stations that a station

  device already wants to access the radio communication channel.

  If, at this instant, the other peripheral stations are in reception mode (step E5), then the DSMi functions of these signal to the GSAi functions that another peripheral station is making an access request and that they must suspend generation and transmission of their sequence

arbitration (step E6).

  Figure 2 illustrates what has just been said.

  In this example, the arbitration sequence consists of a series of bits in which a bit of a first nature corresponds to the part

  said active and the second nature bit corresponds to the so-called passive part.

  For example, the bit of first nature is worth "0" and that of

second nature is "1".

  In this figure, the peripheral communication station SM2 generates and transmits (step E3 of FIG. 7) an arbitration sequence constituted,

  for example, a random sequence of bits during the first time interval.

  The sequence is random to prevent all the sequences from being identical to each other, but it would of course be possible for the arbitration sequences of the peripheral stations to be all predetermined in order to establish priorities for access to the communication channel for all the stations. . It would also be conceivable that only the start of the station arbitration sequence is predetermined in order to establish priorities between said stations, the end of their arbitration sequence being random. By preserving the end of the random sequence this makes it possible to decide between the peripheral stations at the end of the sequence and to prevent certain stations from

  monopolize the radio communication channel.

  As shown in Figure 2, the arbitration sequence consists of three active parts separated from each other by two parts

passive.

  The emission of the first active part corresponds to steps E4 and E7 of the communication method illustrated in FIG. 7, step E7 having a

  duration corresponding to that of an impulse.

  The arbitration sequence not having come to an end, step E8 is followed by step E4, then by step E5 corresponding to the transition to

  reception or detection mode of the SM2 station.

  Since during step E5 of duration equal to that of a pulse, no other presence is detected on the radio communication channel (FIG. 2), step E5 is followed by step E6 then by steps E8, E4 and E7

  because a new active part is present in the arbitration sequence.

  The active part having a duration equal to that of two pulses,

  step E7 is followed once again by steps E8, E4 and E7.

  This arbitration sequence then comprising a passive part and an active part, the corresponding steps already described above are repeated: step E7 is followed by steps E8, E4 and E5 for the passive part,

  then steps E6, E8, E4 and E7 for the active part.

  The DSM2 function of the SM2 station did not detect any other peripheral station wanting to transmit when it was in detection or reception mode since, at that time, the SM station (N-1) was also in detection or reception mode and the SM2 station arbitration sequence is therefore

  terminated without interruption.

  On the side of the base station 12, when an arbitration sequence is transmitted on the radio communication channel, it is received by the latter. The DSB function of the base station detects the presence of this sequence (step S3 of FIG. 8), receives it (step S4) and checks, as indicated in step S5 of FIG. 8, whether said sequence of arbitration is

  terminated without interruption.

  The boolean variable "Detect" stored in the register 16c of the memory 16 is used to mention the fact that a presence is detected on the radio communication channel. When the DSB function detects an MI presence on the radio channel, it sets this "Detect" variable to the value

"true" (step S3 of Figure 8).

  Advantageously, the control step is carried out by detecting the presence of a so-called confirmation bit at the end of the arbitration sequence of each peripheral station, as indicated in FIG. 8 (step S5). The boolean variable "RcvConfirm" stored in the register 16d of the memory 16 is set to the value "true" if the confirmation bit concerning an arbitration sequence has been received (step S5 of FIG. 8). She

  returns to the value "false" when the arbitration sequence has been recorded.

  Peripheral stations SM2 and SM (N-1) have this bit of

  confirmation as shown in Figure 2.

  This prevents the base station receiving a spurious energy pulse via the radio communication channel from deducing that this is the start of an arbitration sequence from a station.

  device and only assign a time window to it.

  Such a parasitic energy pulse can effectively cause the interruption of the sequences transmitted by other stations which are in reception mode (presence of a "0" bit in the arbitration sequences) and lead the station to believe base that a peripheral station wishes to reserve

  access to a radio communication channel.

  When this confirmation bit is not present in the arbitration sequence, this is not retained by the base station and no

  reservation is not envisaged for this station.

  In the example of FIG. 2, the non-interruption information is transmitted to the GSM2 function which transmits this information to the GCSM2 function, the latter then having to expect to receive a message from the base station during the signaling phase of the next communication cycle confirming the allocation of a time window as well as the parameters linked to it. The "PositionWindow" variable indicates the position of the time window in the upward communication phase and this parameter is communicated by the base station during the signaling phase and is

* stored in register 28e of memory 28.

  The variable 'Tfenetre' indicates the duration of the time window dedicated to the peripheral station for the transmission of data frames during the upward communication phase, and this parameter is stored in the

memory register 28f 28.

  To find out whether the arbitration sequence has ended, the algorithm of FIG. 7 performs a test on the variable "Tdelta". The variable "TdeltaT" is used to initialize a timer which is used to indicate the end of a time interval deltaT when the duration has elapsed, that is to say at the end

  an arbitration sequence (step E8 of FIG. 7).

  This variable is stored in register 28g of memory 28.

  Step E8 is then followed by step E9 and the peripheral station

  SM2 awaits the message from the base station.

  The peripheral station will recognize that this message is intended for it by virtue of the fact that the base station will use in this message the arbitration sequence specific to this peripheral station as the latter's identifier. If the information expected from the base station is not received by the peripheral station, this means that an error appeared during the allocation of the time window and step E9 is then followed by step E2: a new access request will be made during the reservation phase of

next communication cycle.

  If the information expected from the base station is received by the peripheral station, step E9 is followed by step E10 and said peripheral station waits for the start of the time window which has been allocated to it during

  of the upward communication phase to come.

  When the start of this time window occurs, the function GCSM2 gives the order to the function TSM2 to send (E1) the data frame stored in the register 28a of the RAM memory 28 during the window

  reserved ("PositionWindow" and "Tfenetre" variables).

  Step Ell is then followed by step E1 and the peripheral station returns to the waiting phase for a new data frame to be transmitted. If we stand on the side of the base station and with reference to FIG. 8, when the DSB function has checked that the arbitration sequence of a peripheral station, for example SM2, has come to an end without interruption (step S5), this is memorized (step S6) in the register 16e of the memory 16. The arbitration sequence is represented by the

  variable "SeqArb 0 to k" where k denotes the number of arbitration sequences.

  When the reservation phase is completed (step S7), the GSB function of the base station signals to the GCSB function the end of said reservation phase and communicates to it (step S8) the information according to which one (or more) station ( s) SMi device (s) has (have) sent an arbitration sequence during a given time interval (s) in order to reserve access to the communication channel and that this (these ) last (s) was (were) accepted, as well as the corresponding arbitration sequence (s). The variable "NbDeltaT" is used to initialize a counter which is used to indicate the end of a reservation phase (step S7 in FIG. 8) when it reaches the value 0. The counter is decremented by one unit at each flow deltaT time interval. This variable can be changed if the

  number of deltaT allocated to each booking phase is unsuitable for traffic.

  The transmission of this information can also be carried out

  after acceptance of each arbitration sequence.

  This information which comes from the implementation of the communication method whose algorithm is represented in FIG. 8 is stored

in RAM 16.

  If the reservation phase is not completed (step S7) then step S3 of detection by the base station of the arbitration sequences

  transmitted on the channel is performed again.

  Returning to FIG. 2, the peripheral communication station SM (N-1) transmits simultaneously with the transmission of the station SM2 during the same first time interval deltaT its own arbitration sequence (step E3 of

Figure 7).

  At the start of the time interval considered, nothing happens given the simultaneous presence of two bits "1" in the respective arbitration sequences of the two stations which explain that they are both in

  transmission mode (steps E4 and E7 in FIG. 7).

  On the other hand, the station SM (N-1) then finds itself, during this same time interval, in detection or reception mode (steps E4 and E5 of FIG. 7) while the station SM2 is in transmission mode (steps E4 and E7

in Figure 7).

  The DSM (N-1) function of the SM station (N-1) detected on the channel

  radio communication station SM2 wanting to send an access request.

  Therefore, the information is transmitted to the GSA function (N-1) which interrupts (step E6 of FIG. 7) the generation of the arbitration sequence of

the station considered.

  This is illustrated in Figure 2 by the fact that bit "1" of the arbitration sequence of the SM station (N-1), which should normally appear

  at this time, is shown in dotted lines.

  The GSA function (N-1) informs the GSM function (N-1) of this interruption and the latter will signal to the GSA function (N-1) the start of the next time interval deltaT (step E12 of FIG. 7) and will ask him to generate and reissue (step E3) an arbitration sequence if the

  reservation does not end (step E13).

  The variable "NbDeltaT" used for the end of phase test of

  reservation is stored in register 28h of memory 28.

  If the reservation phase does not end then step E13 is followed by step E3 and a new arbitration sequence is generated as

shown in Figure 2.

  If, on the contrary, the reservation phase ends (which is not the case for the station SM (N-1) of FIG. 2), the peripheral station must wait for a new communication cycle (step E14) for access a

  new reservation phase (step E2).

  MI In such a case, the GSMi function informs the GCSMi function that the access request must be repeated during the reservation phase of the

next communication cycle.

  The information obtained as a result of the implementation of the communication method, the algorithm of which is shown in FIG. 7 is

  stored in the RAM memory 28 of each peripheral station SMi.

  In accordance with the algorithm represented in FIG. 8, it should be noted that the GSB function of the base station indicates to the GCSB function the end of the reservation phase (interruption step S10 of FIG. 8) in the case o no peripheral station has appeared (not detected in accordance with step S3 of FIG. 8) during the entire interval of

deltaT time (steps S9 and S10).

  The variable "TDeltaT" is used to initialize a timer which is used to indicate the end of a deltaT time interval when the duration is

  elapsed (step S9 in Figure 8).

  This case is illustrated on the last time interval of the

figure 2.

  The end of the reservation phase can be identified very simply by virtue of the presence of a bit in a control register of the base station: the bit is for example initially at "0" at the start of a time interval and it goes to "1" if an arbitration sequence has been issued during this

time interval.

  The bit then returns to the value "0" at the end of this time interval. When additional peripheral stations intervene during the reservation phases of the subsequent communication cycles and that, for example, all the access requests from the stations could not be accepted within the time allocated to these reservation phases, then this duration

  can be adjusted during the next booking phases.

  This adjustment is made according to the number of times that the reservation phase ends at the end of the period provided for this and the

  number of times it was interrupted before the end of this period.

  ItI! I Figures 9 and 10 are alternative embodiments of Figures 3 and 4 and only the elements modified in these figures will bear new references. FIG. 9 (resp.10) represents an information processing device referenced TO '(resp.Ti') which itself comprises a base station 12 (resp.SMi) and a unit generating and receiving data frames

referenced 40 (resp.50).

  This unit generating and receiving data frames depends on the nature of the information processing device (fax machine,

printer, computer ...).

  It should be noted that the unit generating and receiving data frames (resp. 50) can for example be connected by an Ethernet link to an Ethernet card placed in a computer which is itself located.

  remote from the information processing device TO '(resp. Ti'). The invention which has just been described is not limited to the examples of

  achievement mentioned and must, on the contrary, be interpreted as

  embracing all the variants which are within the reach of those skilled in the art.

11i1

Claims (46)

  1. Method for communicating information between a base communication station (12) and a plurality of peripheral communication stations SMi, i = 1, ..., n, on at least one radio communication channel, comprising a phase for reserving access to said radio communication channel by said peripheral communication stations, said method comprising the following steps: - division (Sl) of the duration of said reservation phase into a plurality of consecutive time intervals, - transmission (E4), during the same time interval, by each of said peripheral communication stations SMi of a so-called access request, characterized in that said access request takes the form of a so-called arbitration sequence specific to said corresponding peripheral communication station, each said arbitration sequence consisting of a series of so-called active and passive parts, and in that said method also comprises the steps following steps: -detection (E5, DSMi), during the same time interval, by at least one of said peripheral communication stations having at a given time a passive part in its arbitration sequence of the nature of the part of the arbitration sequences transmitted by other peripheral communication stations at the same time, - interruption (E6, GSAi) of the transmission of the arbitration sequence from said at least one peripheral communication station having detected an active part in the another station's arbitration sequence peripheral communication.   2. Communication method according to claim 1, characterized in that it also comprises, during the following time interval, a step of retransmission (E3, E4) of an arbitration sequence by said at least one station of SMi peripheral communication including the transmission of the sequence   was previously interrupted.   I1P 3. Communication method according to claim 1 or 2, characterized in that the arbitration sequence consists of a series of bits in which a bit of a first nature corresponds to the so-called active part and   the second nature bit corresponds to the so-called passive part.   4. Communication method according to one of claims 1 to 3,   characterized in that, prior to the transmission of an arbitration sequence specific to each peripheral communication station SMi, said method comprises a step of generation (E3) of a random sequence of active parts   and passive constituting said arbitration sequence.   5. Communication method according to one of claims 1 to 3,   characterized in that, prior to the transmission of an arbitration sequence specific to each peripheral communication station SMi, said method comprises a step of generation (E3) of a determined series of parts   active and passive constituting said arbitration sequence.   6. Communication method according to one of claims 1 to 3,   characterized in that, prior to the transmission of an arbitration sequence specific to each peripheral communication station SMi, said method comprises a step of generation (E3), on the one hand, of a determined series of active parts and passive and, on the other hand, a random sequence of parts   both active and passive constituting said arbitration sequence.   7. Communication method according to one of claims 1 to 6,   characterized in that the arbitration sequence specific to each peripheral communication station SMi comprises at least one confirmation bit at the   end of the said arbitration sequence.   8. Communication method according to one of claims 1 to 7,   characterized in that it also includes a step of detecting (S3) and receiving (S4) the arbitration sequences transmitted by the peripheral communication stations SMi as well as the control (S5), by said base communication station, that a station arbitration sequence   of peripheral communication ended without interruption.   9. Communication method according to claims 7 and 8,   characterized in that the step of checking (S5) that an arbitration sequence of a peripheral communication station SMi has come to an end without interruption consists in detecting the presence of a confirmation bit   at the end of the said arbitration sequence.   10. Communication method according to one of claims 1 to   9, characterized in that it comprises a step of interrupting (S10) the reservation phase when no arbitration sequence has been received by said   base station (12) during the entire time interval.   11. Communication method according to one of claims 1 to   , characterized in that the duration of the reservation phase is flexible.   12. Communication method according to one of claims 1 to   11, characterized in that it comprises a signaling phase consecutive to the reservation phase and comprising a step of transmission by said base communication station (12) of a message to the peripheral communication station whose request for access to the radio communication channel has been accepted, said message including the arbitration sequence specific to said peripheral communication station for the purpose of recognizing the message which is destined.   13. Method for communicating information between a peripheral communication station SMi and a base communication station (12) during a phase known as reservation of access to at least one radio communication channel by said communication station peripheral communication, said reservation phase having a duration which is divided into a plurality of consecutive time intervals, said method comprising a step of transmission (E4), by said peripheral communication station, of a so-called access request , during a time interval, characterized in that said access request takes the form of a sequence called arbitration specific to said peripheral communication station and which consists of a series of so-called active and passive parts , and in that said method also comprises the following steps: detection (E5, DSMi), during said same time interval, by said peripheral communication station which presents nte at a given moment a passive part in its arbitration sequence of the nature of the part of 111, 1   arbitration sequences transmitted by other peripheral communication stations at the same time, -interruption (E6, GSMi) of the transmission of the arbitration sequence from the peripheral communication station having detected an active part in the sequence arbitration of another peripheral communication station. 14. Communication method according to claim 13, characterized in that it also comprises, during the following time interval, a step of re-transmission (E3, E4) of an arbitration sequence by said   peripheral communication station having been previously interrupted.   15. Communication method according to claim 13 or 14, characterized in that the arbitration sequence consists of a series of bits in which a bit of a first nature corresponds to the so-called active part and   the second nature bit corresponds to the so-called passive part.   16. Communication method according to one of claims 13 to   , characterized in that, prior to the transmission of an arbitration sequence specific to said peripheral communication station SMi, said method comprises a step of generation (E3) of a random sequence of parts   say active and passive constituting said arbitration sequence.   17. Communication method according to one of claims 13 to   , characterized in that, prior to the transmission of an arbitration sequence specific to said peripheral communication station SMi, said method comprises a step of generation (E3) of a determined series of   so-called active and passive parts constituting said arbitration sequence.   18. Communication method according to one of claims 13 to   , characterized in that, prior to the transmission of an arbitration sequence specific to said peripheral station SMi, said method comprises a step of generation (E3), on the one hand, of a determined series of so-called parts active and passive and, on the other hand, a random sequence of so-called parts   active and passive constituting said arbitration sequence.   19. Communication method according to one of claims 13 to   18, characterized in that the arbitration sequence specific to said peripheral communication station SMi comprises at least one confirmation bit at the   end of the said arbitration sequence.   20. A method of communicating information between a base communication station (12) and a plurality of peripheral communication stations SMi on at least one radio communication channel, comprising a phase of reserving access to said radio communication channel during which said peripheral communication stations wanting to reserve access to said radio communication channel send a so-called access request, said method comprising a step of dividing (S1) the duration of said reservation phase into a plurality of intervals of consecutive times, characterized in that said method further comprises, on the one hand, a step of detecting (S3) and receiving (S4) access requests taking the form of arbitration sequences and transmitted, during 'a same time interval, by said peripheral communication stations and, on the other hand, control (S5) the fact that an arbitration sequence of a station peripheral communication is completed without being interrupted by transmission other arbitration sequences.   21. Communication method according to claim 20, characterized in that each arbitration sequence consists of a series   of so-called active and passive parts.   22. Communication method according to claim 21, characterized in that the arbitration sequence consists of a series of bits in which a bit of a first nature corresponds to the so-called active part and the bit of second nature corresponds to the so-called passive part, and that a bit   said confirmation is placed at the end of each arbitration sequence.   23. The communication method as claimed in claim 22, characterized in that the control step (S5) of the fact that an arbitration sequence of a peripheral communication station has come to an end without being interrupted by the transmission other arbitration sequences consists in detecting the presence of a confirmation bit at the end of said arbitration sequence.   24. Communication method according to one of claims 20   to 23, characterized in that it includes a step of interrupting (SIO) the reservation phase when no arbitration sequence has been received by said base communication station during the entire interval of time.   25. Communication method according to one of claims 20 to   24, characterized in that the duration of the reservation phase is flexible.   26. Communication method according to one of claims 20 to   , characterized in that it comprises a signaling phase consecutive to the reservation phase and comprising a step of transmission by said basic communication station of a message to the peripheral communication station, the request for access to the channel radio communication has been accepted, said message including the arbitration sequence specific to said peripheral communication station for the purpose of recognizing the message which is destined.   27. SMi peripheral communication station capable of transmitting information on at least one radio communication channel to a remote base communication station (12) which itself communicates with a plurality of other SMi peripheral communication stations, said station peripheral communication, on the one hand, before this transmission must reserve access to said communication channel with said base communication station during a so-called reservation phase which is divided into a plurality of consecutive time intervals and, secondly, comprising: -means for sending (30,32,34,36) an access request during a time interval, characterized in that said access request takes the form of '' a so-called arbitration sequence specific to said peripheral communication station and which consists of a series of so-called active and passive parts, and in that said peripheral communication station Risk also includes: -means of detection (30, E5, DSMi), during said same time interval, of the nature of the part of the arbitration sequences transmitted by other peripheral communication stations at the same time, means for interrupting (30, E6, GSAi) the transmission of its own arbitration sequence, during the same time interval, when a passive party appears in its own arbitration sequence and an active party has was detected at the same time in the arbitration sequence of another   peripheral communication station.   28. Peripheral communication station according to claim 27, characterized in that the arbitration sequence consists of a series of bits in which a bit of a first nature corresponds to the so-called active part   and the second nature bit corresponds to the so-called passive part.   29. Peripheral communication station according to claim 27 or 28, characterized in that it comprises means of generation (30, GSAi, E3) of a random sequence of active and passive parts constituting said arbitration sequence.   30. Peripheral communication station according to claim 27 or 28, characterized in that it comprises means of generation (30, GSAi, E3) of a determined series of active and passive parts constituting said arbitration sequence.   31. Peripheral communication station according to claim 27 or 28, characterized in that it comprises means of generation (30, GSAi, E3), on the one hand, of a determined series of active and passive parts and, d on the other hand, from a random sequence of active and passive parts constituting   both said arbitration sequence.   32. Peripheral communication station according to one of   Claims 27 to 31, characterized in that the arbitration sequence specific to   said peripheral communication station comprises at least one bit of   confirmation at the end of the said arbitration sequence.   33. Peripheral communication station according to one of the   Claims 27 to 32, characterized in that it comprises means for   management (30, GSMi) of the time intervals of the reservation phase.   34. Base communication station (12) capable of communicating with a plurality of peripheral communication stations SMi which must, prior to the transmission of information on a radio communication channel, reserve access to said communication channel with said communication channel base communication station during a so-called reservation phase, said base communication station (12) comprising means for dividing (18, S1) the duration of said reservation phase into a plurality of consecutive time intervals , said peripheral stations SMi wishing to reserve access to said radio communication channel transmitting a so-called access request during the same time interval, characterized in that said base communication station (12) comprises means, of a part, of detection (18, S3) and reception (18,20,22,24, S4) of said access requests taking the form of arbitration sequences and transmitted, during the same interval of te mps, by said peripheral communication stations and, on the other hand, by control (18, S5) of the fact that an arbitration sequence of a peripheral communication station has come to an end without being interrupted by   the issuance of other arbitration sequences.   35. Basic communication station (12) according to claim 34, characterized in that it comprises means for interrupting (18, S10) the reservation phase when no arbitration sequence has been received by said base communication station during the entire time interval. 36. Basic communication station (12) according to claim 34 or 35, characterized in that it comprises modulation means (18)   the duration of the reservation phase.   37.Base communication station (12) according to one of   claims 34 to 36, characterized in that it comprises means for   management (18, GSB) of the time intervals of the reservation phase.   38. Base communication station (12) according to one of   Claims 34 to 37, characterized in that it comprises, during a phase   signaling consecutive to the reservation phase, means for transmitting (18,20,22,24) a message to a peripheral communication station whose request for access to the radio communication channel has been accepted, said message including the arbitration sequence specific to said peripheral communication station for the purpose of recognizing the message intended for it. 39.An information processing device (Ti '), characterized in that it comprises a peripheral communication station SMi according to one of the claims 27 to 33.   40. An information processing device (TO '), characterized in that it comprises a base communication station (12) according to one of claims 34 to 38.   41. An information processing device (TO ', Ti') according to claim 39 or 40, characterized in that said information processing device is for example a computer, a printer, a fax machine,   a scanner, digital camera or digital camera.   42. An information communication network (10), characterized in that it comprises a plurality of information processing devices (Ti ') according to claim 39 and an information processing device (TO') according to claim 40.   43. Information communication network (10), characterized in that it comprises a plurality of SMi peripheral communication stations   according to one of claims 27 to 33 and a communication station of   base (12) according to one of claims 34 to 38.   44. An information communication network (10) according to claim 43, characterized in that at least some of said peripheral communication stations SMi are associated with at least one communication device. information processing (Ti).   45. An information communication network (10) according to claim 43, characterized in that the base communication station   (12) is associated with at least one information processing device (TO).   46. An information communication network (10) according to claim 44 or 45, characterized in that said information processing device (Ti) is for example a computer, a printer, a fax machine, a scanner, a digital camera or a digital camera.