Aircraft communication systems and methods

The disclosure herein proposes minimizing the processing and transmission time of an urgent message from an aircraft and relates to a communication system of an aircraft including a set of communication devices or systems intended to transmit data streams, the system including a data processing interface configured to transmit a data stream by dividing it into several data packets and by making the data packets simultaneously pass through different communication devices or systems from among the set of communication devices or systems.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of and priority to French patent application No. 14 62856 filed on Dec. 19, 2014, the entire disclosure of which is incorporated by reference herein.

TECHNICAL FIELD

The present disclosure generally relates to the communication system of an aircraft and, more particularly, to data transmission and methods.

BACKGROUND

The communication system of an aircraft usually comprises various communication devices, systems and/or structures according to several transmission technologies (for example, VHF, HF, SATCOM, WIFI, Cellular) and according to several exchange protocols of the IP, AGARS or ATN type. The exchange protocol is determined by the communication system and possibly by the type of application.

The choice of a communication devices or system at a given time is made according to a predetermined criterion based, for example, on the cost of the communications, the quality of the transmission on the preference of the airline company. Once a communication system has been selected for each type of protocol (AGARS, ATN, IP), it is then used exclusively as long as it is available for transmitting the data steams. The exchange protocol used is determined by the communication device or system itself and possibly by the type of application. Thus, the transmission of a message or of a data stream can be more or less slow as a function of the selected routing strategy.

However, in certain cases, it can be advantageous to transmit the data to the ground as fast as possible. At present the only option is to select the communication device or system offering the highest data rate. This can however prove to be inadequate with the current communication system.

Consequently, a purpose of the present disclosure is to provide an aircraft communication system and method having an architecture which makes it possible to transmit data from the aircraft at maximum speed.

SUMMARY

The disclosure herein proposes minimizing the processing and transmission time of an urgent message from the aircraft to a station on the ground by using different communication devices or systems simultaneously.

The disclosure herein relates to an aircraft communication system comprising a set of communication devices or systems intended to transmit data streams, the system comprising a data processing interface configured or designed to transmit a data stream by dividing it into several data packets and by making the data packets simultaneously pass through different communication devices or systems from among the set of communication devices or systems.

The disclosure herein also relates to a method of communication in an aircraft comprising a set of communication devices or systems intended to transmit data streams, the method comprising:dividing a data stream to be transmitted into several data packets; andsimultaneous transmission of the data packets via different communication devices or systems from among the set of communication devices or systems.

The disclosure herein also relates to a method of communication on the ground, comprising:retrieving a set of data packets transmitted by an aircraft; andreconstructing an initial data stream by re-ordering the data packets using numbers associated with the data packets. The reconstituted data stream can thus be transmitted to the address of its final destination written for example in the header of the data stream.

The disclosure herein also relates to a set of on-board computers comprising a communication system such as defined above. “Set of computers” refers to one or more computers.

Finally, the disclosure herein relates to an aircraft, comprising a communication system such as defined above.

DETAILED DESCRIPTION

A principle of the disclosure herein involves simultaneously using all of the available communication devices or systems in order to reduce, by a maximum amount, the overall transmission time of a same data stream.

FIG. 1is a diagrammatic representation of the architecture of an aircraft communication system according to one embodiment of the disclosure herein. The communication system is generally associated with systems monitoring the correct functioning of the aircraft or with elementary control systems managing particular functions of the aircraft.

The communication system1according to the disclosure herein comprises a data processing interface3and a set5of communication devices or systems (or channels)51-55.

The communication devices or systems51-55are intended to transmit data streams or messages between the aircraft7in flight and a station9on the ground and possibly between different aircraft.

The set of communication devices or systems51-55comprises for example satellite communication devices or systems of the SATCOM type, HF (High Frequency) or VHF (Very High Frequency) broadcast, telephonic of the cellular type, or wireless of the WIFI type.

According to one embodiment of the disclosure herein, the data processing interface3is an access point which is configured to receive a message or a data stream from applications11(for example, monitoring or control systems) of the aircraft and to transmit the data stream to the ground (or possibly to other aircraft) via different communication devices or systems from among the set5of communication devices or systems51-55. In fact, the processing interface3is configured to divide or partition the data stream into several data packets and to make these data packets simultaneously pass through the different available communication devices or systems51-55. “Simultaneously” is understood to mean that the different packets composing a given message are transmitted in parallel and virtually at the same time over the different communication devices or systems.

The processing interface3is thus configured to use, at a given time, the maximum amount of communication devices or systems51-55in parallel in order to carry out the transmission of the data stream from on board the aircraft7in a minimum amount of time. In fact, in certain conditions and in particular in an emergency situation, it can prove to be useful to send data from the aircraft to the ground in the shortest possible time, whatever communication devices or systems are available.

FIG. 2is a block diagram of a communication system in an aircraft according to a preferred embodiment of the disclosure herein.

It will be noted that the communication system can be comprised in one or more computers installed in an aircraft.

According to the disclosure herein, the communication system comprises a set of communication devices or systems51-55intended to transmit data streams and a processing interface3configured to partition each data stream coming from the applications11into several packets and making these packets simultaneously pass though at least one sub-set of the set5of communication devices or systems51-55.

Thus, the processing interface3is an access module which interfaces between the applications11of the aircraft and the communication devices or systems51-55. The processing interface3can correspond to hardware processing system(s) and/or to software installed in one or more computers of the aircraft.

According to this embodiment, the processing interface3comprises a controller31, a selector33and a set35of routers35a,35b,35c.

The routers35implement different protocols of the IP, AGARS or ATN type and are connected to the communication devices or systems51-55. In the example shown, the communication system1comprises three routers35a,35b,35c. A first router35aimplementing the AGARS exchange protocol is connected to two communication devices or systems51and52. A second router35bimplementing the ATN exchange protocol is connected to a single communication device or system53and, finally, a third router35cimplementing the IP exchange protocol is connected to two communication devices or systems54and55. The routers35a-35care thus configured to cause the data to pass though the different communication devices or systems51-55.

The controller31is configured to receive a message or a data stream from the applications11of the aircraft. It will be noted that the data stream comprises, for example in its header, the address of the station9on the ground to which the data are to be sent.

Following a triggering event (for example an emergency situation), the controller31is configured to deactivate the initial routing strategy implemented by the routers35a-35cin order to change into the simultaneous transmission mode. According to this mode, the controller11is configured to divide the data stream into several data packets whilst identifying each one of these packets. In fact, in addition to the destination address and the overall identification of the data stream, each data packet is numbered in order to allow the reconstruction of the initial data stream by reassembling the different packets according to their numbers. Moreover, the controller31is adapted to allocate each data packet with the address of a reconstruction module91in the station9on the ground and which is configured to reconstruct the data stream transmitted by the aircraft.

Advantageously, the controller31is configured to divide the data stream into data packets having sizes compatible with the different exchange protocols relative to the routers35a-35c. Thus, each data packet can be transmitted via any of the routers without taking account of the protocol used.

According to a first variant, the controller31is configured to divide the data stream simply into packets having the same predetermined size.

According to a second variant, the controller31is configured to divide the data stream in an optimal manner into packets having sizes that vary according to the communication devices or systems51-55and/or the exchange protocols relative to the routers35a-35c. This makes it possible to take into account the protocol used in order to optimize the size of the packets. For example small packets can be assigned to the router35adefining the AGARS protocol whilst large packets can be assigned to the router35cdefining the IP protocol having a higher data rate.

Moreover, the selector33is a module coupled on the one hand to the controller31and on the other hand to the routers35. The selector33is configured to establish a correspondence between the set of data packets formed by the controller31and the set of communication devices or systems51-55according to a criterion of availability and/or of data rate relative to each communication device or system. Thus, the selector33is configured to assign each data packet to a corresponding router (i.e. to the router connected to the communication device or system through which the data packet must pass). The selector33thus acts as a generic router which takes account only of the availability of the communication devices or systems51-55. For example, if the communication device or system54is the most free, the selector33sends the current packet to the router35cwhich will use the IP protocol.

According to a particular embodiment of the present disclosure, the criterion of availability and/or of data rate relative to each communication device or system is defined by a counter associated with the communication device or system.

Thus, the communication system comprises a set of counters71-75associated with the set of communication devices or systems51-55. Each counter is configured to determine the size of a queue relative to the communication device or system with which it is associated. In other words, each of the counters71-75measures the number of data packets waiting for transmission by the corresponding communication device or system. The selector33is configured to read the value of the counter associated with each communication device or system and to increment this value when this communication device or system is selected for transmitting a new packet.

According to a variant, a significance is allocated to each counter71-75as a function of the data rate of the communication device or system with which it is associated. Thus, the value of the counter is determined both as a function of the size of the queue and of the data rate of the communication device or system. For example, a communication device or system having a low data rate can for example have its counter increased by a value greater than 1 in order to take account of the fact that the sending of the waiting data packets will require more time.

Thus, the selector33is configured to browse through the set of active communication devices or systems51-55and to establish the correspondence between the data packets and the different communication devices or systems as a function of the values defined by the counters71-75according to the queue and/or data rate criteria relative to each communication devices or systems.

According to another embodiment, the communication system1can be limited to a predetermined sub-set of the set5of communication devices or systems. It is for example possible to exclude the most expensive communication device(s) or system(s) or the communication device(s) or system(s) whose quality of service (i.e. the successful transmission data rate) is not considered to be sufficient, etc. It is also possible to impose the use of a single protocol.

Moreover, according to one or other of the embodiments, the different communication devices or systems51-55selected are intended to transmit the various data packets to a receiving system101installed in a station9on the ground or possibly in another aircraft.

The receiving system101on the ground comprises a reconstruction module91and receiving routers95a-95c. These receiving routers95a-95care routers symmetrical with those of the communication system1of the aircraft and also define different exchange protocols of the IP, AGARS or ATN type. The receiving routers95a-95care thus intended to receive the respective data packets transmitted by the aircraft.

The reconstruction module91is intended to reconstruct the data stream from the different data packets by using the numbering assigned to the latter by the controller31.

FIG. 3is a block diagram of an aircraft communication method according to the embodiment shown inFIG. 2.

Step E1corresponds to the occurrence of an event (for example, a state of emergency) triggering the activation of the simultaneous transmission mode in order to allow the rapid sending of data, for example to a station9on the ground.

In step E2, after the occurrence of the triggering event, the controller31acts on the routers35in order to deactivate the usual routing policies in progress which led to choosing a preferred communication device or system (for example a reference means of the airline company, a system having low communication cost, a system having a high quality of service, etc.).

In step E3, the controller31divides the data stream F received from aircraft applications into data packets P1-Pn. The controller31proceeds with the numbering of each packet knowing that the heterogeneity of the communication devices or systems51-55used can result in an unordered reception of the different packets. The controller31also assigns each data packet with the address of the reconstruction module91.

In step E4, for each data packet, the selector33browses through the list of the active communication devices or systems51-55and selects the one whose counter71-75of packets being processed has the smallest value and then increments that counter. The data packet is then allocated to the router associated with the selected communication device(s) or system(s).

As a variant, steps E3and E4are replaced by a step E34in which the data packets are divided progressively and dynamically into variable sizes as a function of the communication devices or systems and/or of the exchange protocols relative to the routers. Thus, a first packet is created after choosing a communication device or system, then a second packet (possibly of different size) is created after choosing the next communication device or system, and so on.

In step E5, the routers35a-35c, whose routing policy is deactivated, process the packets allocated to them with the required protocols (AGARS, ATN, IP) associated with the selected communication device or system.

According to a first variant, the routers35a-35cthemselves choose the least busy communication device or system. According to a second variant, the routers use the communication device or system imposed by the selector33.

In step E6, the different communication devices or systems51-55selected send the data packets to the address of the reconstruction module91on the ground.

In step E7the routers95a-95con the ground retrieve the different respective data packets and transmit them to the reconstruction module91.

In step E8, the reconstruction module91reassembles the initial data stream F by re-ordering the data packets p1, . . . , Pn using the numbers assigned to them by the controller31.

In step E9, the reconstruction module91transmits the reconstituted data stream F to the address of its final destination written for example in the header of the data stream.

Thus, the communication method is not limited to a single communication device or system and uses all of the available communication device or system in parallel in order to transmit messages to the station on the ground as quickly as possible.