FR3133721A1 - IMPROVED METHOD FOR SELECTING A COMMUNICATION CHANNEL BETWEEN AN AIRCRAFT AND A REMOTE STATION, AND COMMUNICATION SYSTEM EXECUTING THE METHOD. - Google Patents

Abstract

The invention relates to a method for selecting a so-called “best channel” communication channel from a plurality of communication channels (11, 13, 15) between an onboard communication system (100) of an aircraft (1) and a remote communication station (10), the method comprising the steps of determining a so-called “best channel” channel presenting the best end-to-end transmission quality, selecting this channel to carry out redundant communications with those already carried out on a current transmission channel, and, if the channel identified as being the best channel is different from the current channel and remains the best channel after a predetermined duration, interruption of communications on the current channel, the best channel becoming then, in turn, the current channel. Advantageously, it is thus possible to increase the reliability of communications between the aircraft (1) and the remote station (10). Fig. 1

Description

IMPROVED METHOD FOR SELECTING A COMMUNICATION CHANNEL BETWEEN AN AIRCRAFT AND A REMOTE STATION, AND COMMUNICATION SYSTEM EXECUTING THE METHOD.

The present invention relates to a method for selecting a communication channel between an aircraft and a remote communication station, in particular terrestrial. The invention relates more precisely to a method for selecting a channel between an aircraft and a remote communication station, from a plurality of available communication channels, based on one or more pieces of information representative of a quality of communication link. , considered end-to-end (for example latency), of each of these channels, as well as a communication system on board an aircraft and configured to execute the selection process.

STATE OF PRIOR ART

Aircraft most often use a data communication system towards one or more ground stations, allowing operators to carry out radio surveillance of the aircraft, obtaining various operational and logistical information such as, for example, the location of the aircraft but also its condition, in detail, and information relating to possible breakdowns. It is thus possible to organize maintenance actions in advance, after returning to the ground. A well-known system of this type is conventionally called ACARS, an acronym for the English term “Aircraft Communication Addressing and Reporting System”. This system relies on means of communication initially based on HF and VHF transmission channels and more recently on SATCOM type satellite links, particularly in oceanic areas.

In many flight situations, multiple communications channels are available in parallel, and the quality of transmission on these channels can vary differently depending on the channel type. According to certain uses, a list defining channel use preferences is statically defined in an onboard database of the aircraft concerned. In addition, it is sometimes possible to select one channel rather than another channel in view of the operating cost. However, such practices can lead to using a transmission channel that is not the most efficient at a given time. There is therefore a need to be able to select the channel best able to guarantee the best performance in terms of data transmission, and good continuity of service.

Furthermore, depending on the mode of monitoring and management of transmission quality, successive switching of transmission channels may prove counterproductive and it is necessary to find a good balance between the advantage that a change of channel can provide and the risks inherent in too frequent switching.

The situation can be improved.

An object of the present invention is to increase the reliability of data transmissions between an aircraft and a remote station by optimizing the selection of a transmission channel and the conditions for switching from one channel to another channel to minimize the risks. of service interruption.

For this purpose, a method is proposed for selecting a so-called “best channel” communication channel among a plurality of communication channels between a communication system on board an aircraft and a remote communication station, the method comprising the steps :

- i) carry out first communications via a first communication channel among said plurality of communication channels,

- ii) determine, for each of the communication channels of said plurality of communication channels, one or more pieces of information representative of end-to-end transmission quality,

- iii) classify the communication channels of said plurality of communication channels according to indices respectively representative of the end-to-end transmission qualities determined for each of said channels, from said determined information; a single index being assigned for each of the channels,

- iv) determine, from said indices, a second communication channel determined as being the communication channel presenting the best end-to-end transmission quality,

- v) determine said best channel as being the second channel,

- vi) if the best channel is different from the first channel, carry out second communications via the second channel, in parallel with said first communications, and otherwise, repeat steps ii) to vi),

- vii) wait a predetermined period during which steps ii) to iv) are successively repeated, and,

if at the end of said predetermined period the second channel is identical to the best channel, stop operating said first communications, and otherwise stop operating said second communications on the second channel.

The method of selecting a communication channel according to the invention may also include the following characteristics, considered alone or in combination:

- The method further comprises a step of transmitting said indices to the remote station.

- The information representative of end-to-end transmission quality is determined in the form of value intervals.

- The information representative of end-to-end transmission quality is determined from carried out transmissions or protocol messages executing a so-called “ping” mechanism, preferably according to a TCP or ICMP protocol.

- The communications channels used by the process have characteristics defined by a type of channel among: VHF, HF, SATCOM or L-DACS.

- The information representative of end-to-end transmission quality comprises second information representative of the transmission quality through the transmission channel concerned and/or a utilization rate of this channel, or is weighted by said second information.

The invention also relates to a communication system on board an aircraft, configured to operate communications with a remote communication station through a communication channel called "best channel" among a plurality of communication channels, the system being characterized in that it includes electronic and electromagnetic circuits configured to:

- i) carry out first communications via a first communication channel among said plurality of communication channels,

- ii) determine, for each of the communication channels of said plurality of communication channels, one or more pieces of information representative of end-to-end transmission quality,

- iii) classify the communication channels of said plurality of communication channels according to indices respectively representative of the end-to-end transmission qualities determined for each of said channels, from said determined information; a single index being assigned for each of the channels,

- iv) determine, from said indices, a second communication channel determined as being the communication channel presenting the best end-to-end transmission quality,

- v) determine said best channel as being the second channel,

- vi) if the best channel is different from the first channel, carry out second communications via the second channel, in parallel with said first communications, and otherwise, repeat steps ii) to vi),

- vii) wait a predetermined period during which steps ii) to iv) are successively repeated, and,

if at the end of said delay the second channel is identical to the best channel, stop operating said first communications, and otherwise, stop operating said communications on the second channel.

According to one embodiment, the communication system further comprises electronic and electromagnetic circuits configured to transmit said indices to said remote station.

The invention further relates to an aircraft comprising an on-board communication system as mentioned above.

The characteristics of the invention mentioned above, as well as others, will appear more clearly on reading the following description of an exemplary embodiment, said description being made in relation to the attached drawings, among which:

schematically represents a communication system between an aircraft and a remote ground station comprising a plurality of communication channels;

schematically represents a method of classification by performance index of the channels of the communication system represented on the ;

represents a channel selection algorithm comprising the channel classification method illustrated in the ;

schematically represents an example of architecture of a communication system on board the aircraft shown on the ; And,

schematically represents an aircraft comprising the system illustrated on the , configured to execute the channel selection method according to the invention;

DETAILED DESCRIPTION OF EMBODIMENTS

There is a schematic representation of a communication system for the transmission of data between an aircraft 1 operating on the ground or in flight and a remote communication station 10. In the description which follows, we call indifferently "station 10", "remote station 10" or "communication station 10" the remote communication station 10. According to the example described, the communication station 10 is a terrestrial station, but this example is not limiting and the station 10 could be located in different locations space, according to variants. The communication system illustrated on the comprises infrastructures and installations configured to operate data transmissions between the aircraft 1 and the communication station 10, in the upstream direction and in the downstream direction. The upstream direction designates a transmission of data from the remote station 10 to the aircraft 1 and the downstream direction designates a transmission of data from the aircraft 1 to the remote station 10. The communication system illustrated in the allows data transmissions to be carried out between the aircraft 1 and the remote station 10 via a plurality of communication channels. According to the example described, the system comprises three communication channels 11, 13 and 15. Each of the communication channels 11, 13 and 15 comprises an antenna system and a routing link to the remote station 10. Thus, the antenna systems 15 ', 13' and 11' are each configured to respectively operate a communication relay between the aircraft 1 and the remote station 10, in the communication channels 15, 13 and 11. A routing link 15'' of the communication channel 15 operates a relay between the antenna system 15' and the remote station 10; a routing link 13'' operates a relay between the antenna system 13' of the communication channel 13 and the remote station 10, and a routing link 11'' operates a communication relay between the antenna system 11' of the communication channel 11 and the remote station 10. Advantageously, and thanks to the communication system described, the aircraft 1 can transmit a wide variety of data to the remote station 10, in particular for the purposes of precisely locating the aircraft but also of organizing management, operating and maintenance actions, during the flight or after returning to the ground. In addition, the aircraft communication system makes it possible to provide relevant information useful for the operation of the aircraft, such as, for example, meteorological information or relating to a flight plan of the aircraft or of a third party aircraft. According to one embodiment, the communication channel 11 is a communication channel of a type commonly called “HF”; the communication channel 13 is a communication channel of a type commonly called "VHF" and the communication channel 11, which includes a satellite relay device 11s, is a communication channel of a type commonly called "SATCOM".

Advantageously, the aircraft 1 comprises an on-board communication system 100 configured to execute a method of selecting a communication channel among the plurality of selection channels 15, 13 and 11 available, which selected channel is considered to be the "best channel” from at least a first communication performance criterion and possibly other, second communication criteria. The terms “performance criterion” here designate a criterion aimed at evaluating transmission quality, or transmission link quality, from end to end (between the aircraft and a remote communication station). According to the example of embodiment described, the first communication performance criterion is the latency of the channel considered and the second criteria, possibly considered, are communication performance quality criteria such as, for example, a signal ratio noise or information representative of the use made of the channel (use rate, duration of continuous use, error rate, etc.).

According to variants, the first performance criterion aimed at evaluating end-to-end transmission quality is a criterion other than latency, representative of the transmission quality via a communication channel, such as, for example, a signal-to-noise ratio or information representative of the use made of the channel (use rate, duration of continuous use, error rate, etc.) possibly weighted by one or more second criteria.

According to one embodiment, the communication system 100 of the aircraft 1 is configured to begin operating communications towards the remote station 10 as soon as the aircraft is started, on a first communication channel chosen based on criteria performance or based on another criterion. For example, the communication channel used immediately after starting up the aircraft 1 may be the last channel used before stopping the aircraft, a channel chosen arbitrarily, a channel defined according to a regulation or a regulation , or even a channel chosen after a prior evaluation of the performance of the different communication channels available. According to one embodiment, the communication channel initially used is defined in a static list of channels in an aircraft database. According to a variant, a selection of the channel is made by an operator on board the aircraft or on the ground according to an operating cost and the least expensive communication channel to operate is initially chosen. The terms "start-up" of the aircraft 1 designate here a set of actions carried out from the cockpit of the aircraft 1, with a view to its evolution on the ground and/or in flight, and requiring the implementation depending on at least one piece of equipment on board, normally followed by the ignition of the aircraft's engines.

Cleverly, and while first communications are carried out via the first communication channel chosen from the available channels 15, 13 and 11, for example by operating on channel 15 as a first channel, the on-board communication system executes a method of determination of the latency specific to each of the communication channels 15, 13 and 11, based on information collected for this purpose. The latency of a channel is defined here as the complete travel time of data transmitted from the aircraft 1 to the remote station 10 then retransmitted by the remote station 10 to the aircraft 1. The latency thus defined can be expressed as an addition of a so-called down latency and a so-called up latency (respectively associated with the down link and the up link), the local processing times of the remote station 10 then being neglected.

According to one embodiment, the latency of a channel is determined by means of an index representative of a determined latency value or a set of successively determined latency values. The determined latency values mainly constitute the information used to determine a unique latency index for each channel. In other words, a latency index specific to a channel considered can be determined from a determined latency value or from a set of latency values determined for this channel over a given time interval, such as that, for example, a minimum latency, a maximum latency or even an average or median latency. When latency indices are determined for each of the communication channels, the communication channels are classified by index. Thus, the lowest latency index corresponds to the latency index of the communication channel detected as offering the best communication performance among the available channels and the highest latency index corresponds to the latency index of the communication channel detected as offering the worst communication performance in the system illustrated in relation to the , or vice versa. According to one embodiment, information representative of the latency of a channel at a given moment is determined from transmissions which have just been carried out by determining the travel time of an end-to-end data packet .

According to another embodiment, information representative of the latency of a channel at a given moment is determined by the use of a function called "ping", commonly used in communication networks, in particular computer networks, and is relying for example on communications protocols such as TCP (English acronym for “Transmission Control Protocol” and which means “transmission control protocol”) or ICMP (English acronym for “Internet control Message Protocol”, and which means “transmission control protocol”). control of a message on the Internet". Overall, the ping function is a computer command intended to test the accessibility of a remote machine through a communication network and to measure, in the case where the remote machine is accessible, the time taken to receive a response, also called “round-trip time” or “round-trip time” (RTT) in English.

According to another embodiment, the latency of a communication channel is determined from “useful” communications carried out via this channel, and in the absence of sufficiently regular communications, the ping function is used in a manner complementary to “useful” communications. useful.”

In the case of a latency defined from “useful” communications carried out on a communication channel, the data packet(s) used to determine a latency include information similar to that used in messages implementing a ping function. .

Cleverly, after having thus characterized the latencies of different communication channels available between the aircraft and the remote station 10, and consequently the performances of these different channels which are channels 15, 13 and 11, the on-board communication system 100 can check if the channel offering the best communication performance is still the first channel, active and used to carry out first communications at least towards the remote station 10 and possibly from the remote station 10, depending on the channel selection made by the station remote 10 for uplink transmissions. Cleverly and in parallel with this classification of communication channels, the onboard communication system 100 of the aircraft 1 carries out a scan of the best determined communication channel, and the evolution of the classification of the channels over time, so as to be able to carry out a selection of a new communication channel, if necessary, and to have the best channel available.

Thus, if the on-board communication system 100 detects that the channel determined to be the best channel is not the one on (via) which the first communications are carried out, the system begins to operate second communications, via a second communication channel which is the best communication channel detected, in parallel with the first communications carried out on the first channel. In this configuration, the transmissions made between the aircraft 1 and the remote station 10 are redundant and the remote ground station manages the redundancy of the data it receives by eliminating duplicates.

Cleverly, the onboard communication system 100 scrutinizes the evolution of the classification it makes of the channels, in terms of performance, during a predetermined period T1, so that, if at the end of the period T1, the second channel is still the best channel, then the first communications carried out via the first channel are interrupted. In this case, the second communication channel, then the only communication channel, “becomes” the first channel and the second communications “become” the first communications and the process of determining the best channel continues to execute on this new basis. Failing this, the on-board communication system 100 continues to carry out the first communications via the first communication channel. According to a variant, for the on-board communication system 100 to stop operating the first communications and to operate the channel switch between the first communication channel and the second communication channel (determined as the best communication channel), it is appropriate not only that the second channel is the best channel at the end of the delay T1, but also that it has remained so throughout the delay T1, which tends to show and makes it possible to verify that the second communication channel is sufficiently reliable at this moment, or at the very least that it offers performance in line with expectations at that moment. This also makes it possible to create a temporal filter avoiding operating a channel switch when the relative situation of the different channels is not at all stable in terms of performance (transient phenomena).

According to one embodiment, the onboard aircraft communication system 100 transmits to the remote station 10 the classification of the channels by performance index, so that the remote station 10 is informed of the relative quality of the communication channels such as it is evaluated by the aircraft 1. This information can be sent to the remote station 10 in the form of coded and identified data according to a predefined protocol. For example, a packet header carries a recognizable identifier and includes a number of channels, followed by a list of channel identifiers, ordered in ascending or descending order of performance. Thus the remote station 10 can select a communication channel to operate uplink communications, in the case where the latter are not operated via the same communication channel as that used to operate downlink communications. According to one embodiment of the invention, the remote station 10 operates all uplink communication on the last channel used for downlink communication. According to a variant, the remote station 10 uses the information received from the aircraft, relating to the performance of the channels, to select the channel to be used for the uplink communications to follow.

Advantageously, different channel latency evaluation techniques can be implemented to evaluate the latter depending on the type of channel used. For example, the evaluation of the latency of a first channel can be carried out using a ping network command (or function) according to an ICMP protocol and the evaluation of the latency of a second communication channel can be carried out using a network ping command using a TCP protocol. Following a similar reasoning, latencies of only downlinks are used to rank channels in terms of performance.

According to one example, the latency of a communication channel can be determined by deducting the time of transmission of a message from the on-board communication system 100 from the time of reception of this same message by the remote station 10, for this which concerns downlink latency. According to another example, the latency of a channel can be determined by subtracting the reception time of an acknowledgment of receipt, transmitted by the remote station 10 in response to a message transmitted by the aircraft, from the transmission time of this message by the on-board system 100 of the aircraft. Additionally, an approximation can be made to determine an uplink or downlink latency as half the full travel time (RTT).

Obviously, in the case where a ping function is used to determine a latency, the ping network commands or functions include information useful for their proper execution, namely a ping command identifier, a sender identifier, a recipient identifier , a transmission time, a reception time by the recipient, a link type, one or more message routing (control) device identifiers, a quality index determined by the aircraft for the channel used, etc. . This list of examples is not exhaustive.

Advantageously, the evaluation of a channel carried out by the on-board communication system 100 may include other parameters, such as, for example, a link quality index (signal-to-noise ratio, for example), a rate of transmission errors via the link concerned, a jitter (defined as the variation over time of latency), a number of latency measurements carried out over a predetermined time interval, likely to indicate a latency reliability rate determined, an occupancy rate of a communication channel.

For example, the latency indices determined for each of the channels can be weighted by a weighting coefficient defined, for each of the channels, by a transmission quality index and/or by an index representative of use of the channel considered on a predefined time interval.

According to one embodiment, the on-board communication system 100 of the aircraft 1 executes in parallel a first method of evaluating the performance of each of the channels and of classifying the channels according to an index, mainly determined, for each of the channels, from the latency of this channel, and a second method for selecting a best communication channel from the classification carried out in the background. The two processes are in reality two sub-processes of the overall process for selecting a communication channel according to the invention.

There is a flowchart illustrating the overall progress of the process (or more precisely sub-process) of evaluating the performance of each of the communication channels available between the aircraft 1 and the remote station 10, of defining a unique index per channel determined from the latency of the channel, possibly weighted by another transmission performance index, then classification of the communication channels, according to the determined indices, so as to define an established order, starting from the best communication channel to the least good communication channel or vice versa.

A step S0 is a step of initializing the systems of the aircraft 1, at the end of which the systems of the aircraft are supplied with electrical energy, initialized and normally operational. In particular, the on-board communication system 100 is configured to be able to operate the first communications on a first available and selected communication channel, in particular towards the remote station 10. During a step S1, ping commands are executed at regular intervals on all the communication channels available between the aircraft 1 and the remote station 10, so as to define one or more latency information for each of the channels. The ping command execution frequency is, in one example, such that a ping command is sent once every 30 seconds. This frequency of measuring the latency of a communication channel can, however, be increased or decreased depending on the results observed on each of the communication channels. In addition, this evaluation frequency per channel may differ from one channel to another channel, depending on the type of channel, in particular. According to a variant embodiment, “useful” communications are sufficiently frequent to not have to resort to the use of ping commands, and the current communications are used to define the latency of each of the available communication channels. The data packets exchanged on the channel then contain all the information useful for determining latency, that is to say information equivalent to that present in a ping command to carry out a latency calculation. A range of latency values and an average latency value can be defined for each of the communication channels 11, 13 and 15 and a latency index can be determined from this latency information. A latency index may be determined, for example, such that the channel with the highest latency is assigned a latency index equal to 10 and the channel with the lowest latency is assigned a latency index equal to 0, or vice versa, depending on the index definition convention used. Typically, in the embedded communication system 100, the latency values are expressed in seconds. The evaluation of the latency of each channel is thus carried out for a duration T1, usually several minutes.

During a step S2, the latency indices defined for each of the channels are recorded in a table and the channels are classified in this table in order of performance (latencies or weighted latencies). The channel classification table is for example recorded in a volatile or non-volatile memory of the on-board communication system 100 of the aircraft 1. A step S3 consists of identifying the communication channel whose index is representative of the best performance communication, so that the improved method of selecting a communication channel, executed by the on-board system 100, can, by a simple reading from memory, know the channel presenting the best communication conditions towards the remote station 10.

After step S3, the process loops back to step S1, which amounts to saying that the evaluation of the channel latency is carried out continuously, in the background, by the on-board communication system 100 of the aircraft 1. In the case where second information, representative of the quality of channel transmission, is used to weight the latency indices of the channels, these operations are executed during step S1 and the weighted indices are considered for the classification carried out in step S2. In this case, the information representative of the quality of transmissions is defined as protocol and transmitted during the exchange of messages between the aircraft 1 and the remote station 10, but also, possibly from third party communications, carried out towards reference equipment .

There illustrates steps for selecting a communication channel referenced as being the best communication channel available between the aircraft 1 and the remote station 10, among channels 15, 13 and 11. This is also, more precisely, of a sub-process of the improved method of selecting a communication channel according to the invention, since according to the embodiment described, two sub-processes executed in parallel operate the steps of the complete process. A step S0' corresponds to an initialization step of the systems of the aircraft 1, at the end of which the systems are supplied with energy, initialized and normally operational. In particular, the onboard communication system 100 is configured to be able to operate the first communications on a first available and selected communication channel, in particular towards the remote station 10. According to one embodiment, the steps S0 and S0' are combined in a single step called “start-up” of the aircraft. During a step S10, the onboard communication system 100 of the aircraft 1 sends first information (data) to the remote station 10, after having selected a first communication channel to the remote station 10 then waits, when a step S20, for a duration T1 (from several seconds to several minutes, typically), that a determination of the best channel can be carried out in the background, so as to be able to determine, at the end of a step S30, whether the first channel selected to operate the first communications is the best channel or not. In the case where it is determined, in step S30, that the channel currently used (i.e. the first channel) is the best channel, the method loops back to step S10 and therefore continues to operate communications with the remote station via the first channel. Otherwise, that is to say if the current channel is not the best channel, the method initiates, during a step S40, additional communications, also called here second communications, via a second communication channel. communication which is none other than the channel determined as being the best channel by reading the information included in the memory of the on-board communication system 100, and updated by the continuous execution of the sub-process illustrated in relation to the . A new wait, of a duration T2, is then carried out during a step S50, with the aim of producing a “temporal filter”, that is to say with the aim of being able to check whether the second channel continues to offer the best communication performance at the end of the T2 delay. To do this, a new reading of the best communication channel is carried out during a step S60, at the end of the delay T2. According to one embodiment of the invention, the duration T2 is between 1 minute and 4 minutes, preferably 2 minutes.

In the case where the second channel is still the best channel at the end of the delay T2, the first communications carried out on the first channel are stopped during a step S70 and the process loops back to step S10. In this case, the second channel is then considered as the first channel for the reiteration of the sub-process described and the second communications are then considered as the first communications. Otherwise, that is to say if another channel is determined to be the best communication channel at the end of the delay T2 during step S60, the second communications carried out on the second channel are stopped during a step S80 and the first communications continue to be carried out on the first channel, then the process loops back to step S10. Advantageously and according to one embodiment of the invention, it is verified during steps S50 and S60 that the second communication channel remains the best communication channel for the entire duration of the delay T2. Failing this, additional information is defined (an indicator of variation of the best channel during the delay T2) making it possible to force the result of the test carried out during step S60.

According to one embodiment of the invention, the selection method described can be deactivated by an operator in the aircraft or on the ground to then carry out a communication channel selection from a second selection method, using for example statically defined communication channel preference criteria.

There schematically illustrates an example of internal architecture of the on-board communication system 100 of the aircraft 1.

According to the hardware architecture example shown in , the on-board communication system 100 then comprises, connected by a communication bus 1000: a processor or CPU (“Central Processing Unit” in English) 101; a RAM (“Random Access Memory” in English) 102; a ROM (“Read Only Memory” in English) 103; a storage unit such as a hard disk (or a storage media reader, such as an SD card reader ("Secure Digital" in English) 104; communication interfaces 105, 106 and 107 configured to operate communications on, respectively, the communication channels 11, 13 and 15. The on-board communication system 100 further comprises interfaces of the input/output port type, in particular capable of receiving and transmitting signals from and to third-party devices of the aircraft.

Processor 101 is capable of executing instructions loaded into RAM 102 from ROM 103, external memory (not shown), storage media (such as an SD card), or attached to a communications network. When the onboard communication system 100 is powered on, the processor 101 is capable of reading instructions from the RAM 102 and executing them. These instructions form a computer program causing the implementation, by the processor 101, of the method and sub-processes described in relation to the And or a process derived therefrom.

All or part of the method implemented by the on-board communication system 100, or its variants described, can be implemented in software form by execution of a set of instructions by a programmable machine, for example a DSP (“Digital Signal Processor” in English) or a microcontroller, or be implemented in hardware form by a machine or a dedicated component, for example an FPGA (“Field-Programmable Gate Array” in English) or an ASIC (“Application-Specific Integrated Circuit” in English). In general, the on-board communication system 100 comprises electronic circuitry configured to implement the methods and sub-processes described in relation to itself making it possible to operate communications between the aircraft 1 and the remote station 10. obviously, the on-board communication system 100 further comprises all the elements usually present in a system comprising a control unit and its peripherals, such as a power supply circuit, a power supply supervision circuit, one or more control circuits. clock, a reset circuit, input-output ports, interrupt inputs, bus drivers, digital to analog and analog to digital converters, ideally fast. This list is not exhaustive.

There represents the aircraft 1 comprising the on-board communication system 100 advantageously making it possible to increase the reliability of communications with the remote station 10, by operating an optimized selection of the best communication channel among the channels available for communicating with the remote station 10, according to a first performance criterion defined from information representative of end-to-end transmission quality via this channel (for example channel latency), as well as possibly one or more second determined transmission quality criteria and used to weight the first criterion.

Claims (9)

Method for selecting a so-called “best channel” communication channel from a plurality of communication channels (11, 13, 15) between an on-board communication system (100) of an aircraft (1) and a communication station ( 10) remote, the method comprising the steps:

• i) carry out first communications (S10) via a first communication channel among said plurality of communication channels (11, 13, 15),
• ii) determine (S1), for each of the communication channels (11, 13, 15) of said plurality of communication channels, one or more pieces of information representative of end-to-end transmission quality,
• iii) classify the communication channels (S2) of said plurality of communication channels according to indices respectively representative of the end-to-end transmission qualities determined for each of said channels, from said determined information; a single index being assigned for each of the channels,
• iv) determine (S3), from said indices, a second communication channel determined as being the communication channel presenting the best end-to-end transmission quality,
• v) determine (S3) said best channel as being the second channel,
• vi) if the best channel is different from the first channel (S30), carry out second communications via the second channel (S40), in parallel with said first communications, and otherwise, repeat steps ii) to vi),
• vii) wait (S50) for a predetermined period (T2) during which steps ii) to iv) are successively repeated, and,

if at the end of said predetermined period (T2) the second channel is identical to the best channel, stop operating (S70) said first communications, and otherwise, stop operating (S80) said communications on the second channel. Method of selecting a communication channel according to claim 1 further comprising a step of transmitting said indices to the remote station. Method for selecting a communication channel according to one of claims 1 and 2, in which the information representative of end-to-end transmission quality is determined in the form of value intervals. Method for selecting a communication channel according to one of claims 1 to 3, in which the information representative of end-to-end transmission quality is determined from carried out transmissions or protocol messages executing a so-called mechanism of “ping”, preferably according to a TCP protocol or an ICMP protocol. Method for selecting a communication channel according to one of claims 1 to 4, in which the communications channels have characteristics defined by a type of channel among: VHF, HF, SATCOM, L-DACS. Method for selecting a communication channel according to one of claims 1 to 5, in which the information representative of end-to-end transmission quality further comprises second information representative of the transmission quality through the transmission channel concerned and/or a utilization rate of this channel, or are weighted by said second information. Onboard communication system (100) in an aircraft (1), configured to operate communications with a remote communication station (10) through a communication channel (11, 13, 15) called “best channel” among a plurality of communication channels (11, 13, 15), the on-board system 100 being characterized in that it comprises electronic and electromagnetic circuits configured to:
- i) carry out first communications via a first communication channel among said plurality of communication channels,
- ii) determine, for each of the communication channels of said plurality of communication channels, one or more pieces of information representative of end-to-end transmission quality,
- iii) classify the communication channels of said plurality of communication channels according to indices respectively representative of the end-to-end transmission qualities determined for each of said channels, from said determined information; a single index being assigned for each of the channels,
- iv) determine, from said indices, a second communication channel determined as being the communication channel presenting the best end-to-end transmission quality,
- v) determine said best channel as being the second channel,
- vi) if the best channel is different from the first channel, carry out second communications via the second channel, in parallel with said first communications, and otherwise, repeat steps ii) to vi),
- vii) wait a predetermined period during which steps ii) to iv) are successively repeated, and,
if at the end of said delay the second channel is identical to the best channel, stop carrying out said first communications. On-board communication system (100) according to claim 7 further comprising electronic and electromagnetic circuitry configured to transmit said indices to said remote station. Aircraft (1) comprising an on-board communication system (100) according to one of claims 7 and 8.