SEMANTIC DATA EXCHANGE SYSTEM WITH A SEMANTIC RETRANSMISSION CHANNEL

Abstract

The invention relates to a semantic data exchange system between at least one data transmitter (10, 11) and at least one data receiver (13) communicating via a communication channel (12) characterized in that it comprises in combination at least the following elements: - A transmitter (10) comprising a semantic data generator (11) and a BGKS knowledge base, - A receiver (13) comprising a semantic data interpreter module (14) configured to interpret the received semantic data, and a BGKD knowledge base, - A .A semantic interpretation control module (15) configured to control the interpretation of semantic data from the semantic data interpreter module; a feedback channel (17) between the receiver and the sender, and a feedback channel (18) between the data control module and the semantic data interpreter module, transmitting an ACK or NACK acknowledgment generated by the control module (15). Figure for the abbreviation: Fig. 1.

Description

Title of the invention: SEMANTIC DATA EXCHANGE SYSTEM WITH A SEMANTIC RETRANSMISSION CHANNEL

[0001] The invention relates to a system for exchanging semantic data comprising a channel for retransmitting semantic data in the event of a “reading” error (interpretation or understanding) of the transmitted semantic data.

[0002] The invention finds, for example, its application in semantic communication systems and in oriented communication systems, i.e., in which the purpose of the communication is known or estimated at the receiver.

[0003] It can also be used in data exchange systems respecting a semantic message format. For example, the invention can be used in “edge cloud” type applications.

[0004] It applies in any “semantic communication” system comprising one or more semantic data transmitters, such as a mobile telephone, a smart mobile telephone known by the Anglo-Saxon term “Smartphone”, a mobile peripheral host known by the Anglo-Saxon abbreviation of “mobile edge host”, or in systems comprising devices of the Internet of Things or loT (Internet of Things) type.

[0005] Communication has been classified by Shannon and Weaver into three levels: (i) the transmission of symbols, (ii) the semantic exchange of transmitted symbols, (iii) the effect of the exchange of semantic information. In recent decades, communications have mainly focused on how to accurately and efficiently transmit symbols from the transmitter to the receiver. Today, with the development of next-generation wireless communication systems, such as 5G and beyond, there is a need for solutions in communication exchanges to “distill” data (choose useful data for transmission) to enable “reliable cognition” and task execution at the receiver.

[0006] The prior art describes different systems for retransmitting messages or data following transmission errors.

[0007] Conventional automatic retransmission mechanisms of the ARQ (Automatic Repeat Request) type or in their hybrid version HARQ where the retransmitted packets are recombined at the receiver, handle transmission errors detected at the receiver which are due to wireless channel errors. These mechanisms do not take into account the “semantic” nature of the message.

[0008] Some brief reminders relating to the retransmission protocols known from the prior art are set out below.

[0009] Error control schemes in data transmission systems can be classified into two broad categories: ARQ schemes and forward error correction FEC schemes.

[0010] ARQ protocols are used for reliable data transmission in wireless communications. In these protocols, the transmitter sends a packet consisting of payload bits and an error detection code, usually a CRC (Cyclic Redundancy Check) code. The receiver verifies the integrity of the packet by decoding the error detection code. Depending on the result of the decoder, a positive acknowledgment ACK (error-free decoding) or a negative acknowledgment NACK is returned to the data sender. The transmitter retransmits the message when it has received a negative acknowledgment.

[0011] The "stop and wait" technique, known as "stop and wait", is the simplest and is well suited to a simple communication protocol. A stop and wait protocol transmits a packet to a receiver and waits for a response. The receiver receives each packet and sends a positive acknowledgment ACK if the packet is received correctly and a negative acknowledgment NACK if the packet is received with errors. In practice, the receiver may not be able to reliably identify whether a packet has been received and the transmitter will need to implement a "timer" to check that the receiver is responding. In the case of a normal transmission, the transmitter will receive a positive acknowledgment ACK for the data and then begin transmission of the next packet. While waiting, the transmitter is said to be in the "idle" state and is unable to send any further data to that destination.

[0012] Another technique is called "Go-Back". Packets are transmitted without waiting for ACK or NACK acknowledgments, until the transmitter receives feedback from the receiver. Then, in case of a transmission error, the transmitter goes back the sequence numbers of the erroneous packet and retransmits all packets starting from this sequence number. This technique is easy to implement, but it also introduces a significant load in the retransmission, because correctly transmitted packets may have to be retransmitted several times before being delivered to the upper layers of the transmission system. In addition, the average delay of the connections is also higher.

[0013] The functionalities required for the “Go-Back-N ARQ” technique are summarized below:

[0014] To support the Go-Back-N ARQ technique, a protocol numbers each packet sent,

[0015] The local node keeps a buffer containing all packets that have been sent, but have not yet been acknowledged,

[0016] The receiver of the remote node keeps a record of the packet with the highest number that was correctly received. This number corresponds to the last acknowledgment packet that it was able to transmit.

[0017] Recovering a corrupted packet takes place in three steps:

[0018] First, the corrupted packet is discarded at the receiver of the remote node,

[0019] The remote node then requests retransmission of the missing packet using a control packet (sometimes called NACK or REJECT). The receiver discards all packets that do not have the requested packet number,

[0020] The last step consists of retransmitting the lost packet(s).

[0021] A third method of retransmission is selective repeat transmission. “SR ARQ”. Packets are transmitted continuously as in the method "Go-to-Back", but only packets with a negative acknowledgment are retransmitted. The functionality required to support a selective repeat protocol is the same as that required for the "Go-to-Back" technique, with a buffer of frames at the receiver that have been received but not yet acknowledged. Recovering a corrupted packet using selective repeat, known as "Selective Repeat ARQ", involves performing the following four steps:

[0022] The corrupted data packet is discarded at the receiver of a remote node,

[0023] The remote node requests retransmission of the missing packet using a control packet, sometimes called a selective discard,

[0024] The receiver then stores all out-of-sequence packets in the receive buffer until the requested packet has been retransmitted,

[0025] The transmitter receives the retransmission request and transmits the lost packet(s),

[0026] The receiver transmits the retransmitted packet and all subsequent in-sequence packets which are kept in the receiver's buffer.

[0027] Upon receipt of a selective repeat control packet (by the local node), the transmitter sends a single packet from its buffer of unacknowledged packets. The transmitter then continues normal transmission of new packets until the packets are acknowledged or another selective repeat request is received.

[0028] The techniques known in the prior art do not allow the problem of transmission error in semantic communication systems to be solved and do not take into account the nature of semantic communication.

[0029] The notions of semantic equivalence or semantic similarity are known from the prior art, for example in the publication by Floridi. L, entitled “outline of a theory of strongly semantic information. Minds Mach. 14, 2 (2004), 197-221.; or the publication by D'ALFONSO, S. entitled “On quantifying semantic information”. Information 2, 1 (2011), 61-101.).

[0030] The idea of ​​the present invention is to propose a system for exchanging semantic data, said exchange system comprising a semantic retransmission channel which takes into account the semantic nature of the exchange of semantic data and which effectively adapts the retransmitted information accordingly.

[0031] The invention relates to a system for exchanging semantic data between at least one semantic data transmitter and at least one semantic data receiver communicating via a transmission channel, characterized in that it comprises in combination at least the following elements:

[0032] - A transmitter comprising a semantic data generator and a database BGKS knowledge,

[0033] - A receiver comprising a configured semantic data interpreter module to interpret the received semantic data, and a BGKD knowledge base,

[0034] - A semantic interpretation control module configured to control the interpretation of semantic data from the semantic data interpreter module,

[0035] - A module for choosing the modifications to be made for the generation of the message mantic,

[0036] - A return path between the receiver and the transmitter, and a return path between the data control module and the semantic data interpreter module, said channel transmitting an acknowledgment of correct receipt ACK or of erroneous receipt NACK generated by the control module.

[0037] The system may comprise a data aggregation module MA disposed between the semantic data interpreter module and the semantic interpretation control module.

[0038] The semantic data exchange system is, for example, a semantic data communication system in the form of semantic messages or an “edge cloud” type system.

[0039] The invention also relates to a method for exchanging semantic data between at least one semantic data transmitter and a semantic data receiver via a transmission channel, characterized in that it comprises at least the following steps:

[0040] - A semantic interpretation control module controls the interpretation of the semantic data,

[0041] - If the interpretation is correct, then the semantic data is transmitted,

[0042] - If the interpretation of the semantic data is incorrect, the control module semantic interpretation transmits information to the transmitter so that the semantic data generation module generates new semantic data before retransmission to the receiver.

[0043] The semantic data generation module may use data from a knowledge database to generate new semantic data.

[0044] The semantic interpretation control step uses, for example, knowledge graphs in order to detect the semantic similarity or equivalent similarity of the semantic data.

[0045] Other characteristics, details and advantages of the invention will emerge on reading the description given with reference to the appended drawings given by way of illustrative and non-limiting example and which represent, respectively:

[0046] [Fig.l], a diagram illustrating the semantic communication system according to the invention comprising a retransmission channel,

[0047] [Fig.2], an illustration of the steps implemented for the method according to the invention.

[0048] In the field of semantic data exchange, the objective is not to re to produce, exactly or approximately, the data or semantic message transmitted, but rather to obtain a faithful and understandable interpretation of the content of the data.

[0049] For example, considering the conversation between three people:

[0050] Giulio: "Are you home this weekend?"

[0051] Livio: "Emilio, Giulio is asking if you are free to play with us this weekend."

[0052] Emilio: "No, I'm not available on Saturdays and Sundays."

[0053] Livio serves as a semantic channel between Giulio and Emilio. Livio does not transmit pre precisely Giulio's original message to Emilio. However, Emilio is still able to preserve the original meaning of Giulio's message.

[0054] There may be transmission errors of the "x" symbols due to the wireless channel. However, there is no semantic failure since Emilio understands the meaning of Giulio's message.

[0055] One of the objectives of the present invention is therefore to avoid errors of interpretation at the level of the received message or to correct them by retransmitting data which will have been misinterpreted, making the content of the semantic message incomprehensible to the recipient. To better understand the object of the invention, the following description is given as a non-limiting example in the case of a semantic communication system.

[0056] [Fig.l] illustrates an example of a semantic communication system according to the invention. A transmitting source 9 is connected to a transmitter 10 comprising a semantic message generator 11. Said semantic message generator 11 is configured to transmit via a wireless communication channel 12 a message semantics to a receiver 13 comprising a message interpreter module 14 whose output is connected to a message interpretation control module 15. The output of the message interpretation control module 15 is connected to a recipient 16 when the result of the interpretation control is correct, i.e., the recipient will be able to interpret the content of the message without error and to a module 17 configured to determine the “parameters” to be adapted by the message generator. The message interpretation module 14 suggests the interpretation of the received message w'.

[0057] The system according to the invention comprises a BGKS knowledge base at the transmitter level and a BGKD knowledge base at the receiver level.

[0058] The message interpretation control module generates a correct interpretation result, OK, to validate the semantic understanding of the message by the interpreter module or an incorrect interpretation result, not OK otherwise. In the case where the message has been correctly semantically decoded, the message is delivered to its recipient 16.

[0059] In the event that the message could not be interpreted correctly, the message interpretation control module transmits via a return channel 18 to the transmitter an acknowledgment of erroneous receipt, NACK, (erroneous interpretation of the message) and this same information to the message interpreter via an internal communication channel 19.

[0060] The message generator module at the transmitter level, when it receives NACK information of incorrect interpretation of the message, will generate a new message.

[0061] To decide on the “retransmission” of a semantic message following an erroneous acknowledgment of receipt, the message generator takes into account a semantic interpretation function qs from the knowledge base of the transmitter BGKS to generate a message x=gj(w) where gj is a semantic interpretation function with j=l....k forming a semantic interpretation engine.

[0062] [Fig.2] illustrates a succession of steps implemented by the method according to the invention for the retransmission of a semantic message following an erroneous interpretation of this semantic message.

[0063] The first step, 21, is a step of checking the understanding or interpretation of the content of the message carried out at the receiver. For this, the semantic message interpreter module can use the knowledge graphs for the detection of semantic similarity or equivalent which are expected at reception taking into account the BGKD knowledge base present at the receiver. It is also possible to take into account the partial or total BGKS knowledge base at the sender (message generator).

[0064] The received message w' is transmitted to the message interpretation module which will suggest, 22, a semantic interpretation of the message content.

[0065] At the receiver level, the semantic message interpretation control module is responsible for drawing a conclusion on the understanding of the received message thanks to the interpreted received message w' and the receiver's knowledge base.

[0066] The control module validates the interpretation of the semantic message 23 or indicates the presence of an error 25 by transmitting the “erroneous interpretation” NACK information to the transmitter 26.

[0067] If the interpretation of the semantic message is correct, then a following message can be sent by the transmitter, 24.

[0068] For a semantic message which is incomprehensible at the receiver, and following the reception of the NACK information, the semantic message generation module will generate a new semantic message, 26 and send it to the receiver, 27.

[0069] The message interpreter module may suggest an interpretation vector, different options for interpreting the message and associate with each interpretation vector li a confidence value w). This confidence value corresponds to a probability that an interpretation is semantically identical to the semantic message sent. The confidence value w'i may also indicate the probability that the interpretation of the message made by the message interpreter module is semantically equivalent to the transmitted message. The confidence values ​​may be used to define modifications in the generation of the semantic message in order to improve the quality of the transmission.

[0070] The system can also include a module for "aggregating different information", MA (dotted in [Fig.l]). After each semantic message received, the receiver accumulates (sums) each of the interpreted messages and performs an interpretation check on the sum resulting from this aggregation (set of interpreted semantic messages). An interpretation score Si is associated with the aggregated interpretation (sum of interpreted messages). When the sequence of semantic messages can be interpreted more precisely, and when the meaning of the sequence of semantic messages can be interpreted, this information is transmitted to the receiver to be used in checking for erroneous interpretation of the semantic message. When all the semantic messages have been correctly received, the interpretation is correct, the receiver transmits to the transmitter a semantic acknowledgment of receipt, ACK-Semantic.The transmitter can then start a new communication, transmit a new message sent by the transmitter can be received.

[0071] When the information is available at the transmitter level, the BGKS knowledge base or the BGKD knowledge base will be used in whole or in part. The interpretation vector w' is transmitted to the correction module. An erroneous interpretation is detected and a semantic retransmission mechanism is triggered. The receiver will transmit the transmission error it detected to the sender of the semantic message.

[0072] It is possible that the semantic message is correct at the transmission level, but that the interpretation is erroneous at the receiver level. This can result from various phenomena which will generate several actions to be undertaken during the message generation stage.

[0073] A first cause results from wireless communication errors, losses at the coding source, noise phenomena at the transmission channel, losses in the decoding of the wireless channel or a combination of these different elements.

[0074] When the received message 'y' contains too many errors to be correctly interpreted, the prior knowledge or semantic "Background" cannot systematically recover the errors and a retransmission of the semantic message x is mandatory. For example, the message sent is "Fire", the interpreted semantic message is "Hike", the letters H and k contained in the received message do not correspond to the initial letters F and r. The message cannot be correctly interpreted. For the physical transmission of the messages, conventional retransmission mechanisms will be used by returning the acknowledgments on the HARQ (Hybrid Automatic Repeat Request) packets. The message generator at the transmitter does not need to generate a new semantic message or new semantics for the message.

[0075] In some cases, the knowledge base at the receiver will not contain the information necessary for correct interpretation of the message.

[0076] When noise or wireless interference did not cause errors at reception, the message "y" was correctly decoded. However, if the receiver's BKGD knowledge base does not include the necessary elements, the message interpreter may arrive at an erroneous interpretation of the semantic message. In this case, the retransmission mechanisms according to the prior art are insufficient. Semantic information is necessary for the correction of the semantic message and for the retransmission of the semantic message.

[0077] The semantic message will be regenerated with a "semantic equivalence". The receiver informs the transmitter by transmitting an erroneous acknowledgment, or NACK, that a new transmission or retransmission of the message is necessary. Retransmission of a semantic message does not systematically result in correct reception, i.e., successful interpretation (without misinterpretation) of the semantic message.

[0078] In the case where the receiver has a value aggregation module, the semantic retransmission can trigger the emission of additional messages linked to previous messages, the latter not necessarily being equivalent semantic messages.

[0079] In some cases, there will be a mismatch between the received semantic message and the target objective of the communication. This occurs in particular when the purpose or object of the communication is not explicitly indicated and is misinterpreted by the receiver's interpretation module. The incorrect interpretation of the objective of the communication may be due to a semantic communication error or to an erroneous estimation of the knowledge bases of the transmitter and / or the receiver. This leads to a misinterpretation of the received signal since the interpretation function qD selected by the receiver's interpretation module to interpret the semantic message does not lead to correct semantics or leads to equivalent semantic interpretations. The receiver activates a semantic retransmission to reinforce the receiver's semantic information to resolve this problem.

[0080] When the receiver indicates in a semantic acknowledgment NACK of misinterpretation that it does not understand the purpose of the communication, the sender may decide to transmit semantic equivalents to increase the probability that the receiver correctly interprets the semantics of the received message. The sender may also explicitly transmit information about the purpose (objective) of the communication.

[0081] The message generator of the sender or a semantic encoder generates a new semantic message taking into account different strategies. The message generator has a certain freedom to ensure the generation of a semantic message that will be interpreted correctly.

[0082] For example, the message generator may generate and transmit messages whose message is more precise or easier to generate (based on a cost function) or even more relevant to the recipient's expectations.

[0083] The semantic message generator can also modify the method it uses for message generation. It can reduce the redundancy of transmitted messages, improve reliability in transmissions (channel coding).

[0084] The semantic retransmission actions according to the invention may also include the following actions:

[0085] The message generator can also use a filter that will generate a semantic message containing more useful data with a lower compression rate. It can use a storage unit (not shown for reasons of simplification of the figure).

[0086] The message generator may decide to emit the identical semantic messages. The semantic message may be exactly the same or a message enriched with one or more semantic contents.

[0087] The semantic equivalent. The sender may decide to transmit semantic equivalent messages. Considering the example of a fire in a forest. The first objective of the communication is to transmit the semantics "FIRE". In case of misinterpretation or the fact that the sender is an unknown sender, then the sender may transmit semantically equivalent words, such as temperature, smoke, alert, fog, etc.

[0088] The message generator may also transmit an additional explanation about the purpose of the communication. The misinterpretation of the message by the receiver may result from a misunderstanding or misinterpretation of the purpose of the communication. If the sender is notified, with a dedicated semantic NACK, the sender may transmit an additional explanation in the form of a semantic message or additional information about the purpose of the communication or decide to explicitly transmit this information.

[0089] The explanations which have just been given in the case of a semantic communication system apply in the case of a “egde cloud” type system.

[0090] The system and method according to the invention make it possible to improve the exchange of semantic data within the framework of a semantic message communication system or any system exchanging semantic data.

Claims

Claims

1. System for exchanging semantic data between at least one semantic data transmitter (10, 11) and at least one semantic data receiver (13) communicating via a transmission channel (12) characterized in that it comprises in combination at least the following elements: - A transmitter (10) comprising a semantic data generator (11) and a BGKS knowledge base, - A receiver (13) comprising a semantic data interpreter module (14) configured to interpret the received semantic data, and a BGKD knowledge base, - A .semantic interpretation control module (15) configured to control the interpretation of the semantic data from the semantic data interpreter module, - A module (17) for choosing the modifications to be made for the generation of the semantic message by the semantic message generator of the transmitter, - A return channel (18) between the receiver and the transmitter, and a return channel (19) between the data control module and the semantic data interpreter module, transmitting an acknowledgment of correct receipt ACK or of erroneous receipt NACK generated by the control module (15).

2. Semantic data exchange system according to claim 1 characterized in that it comprises a data aggregation module MA arranged between the semantic data interpreter module (14) and the semantic interpretation control module (15).

3. Semantic data exchange system according to one of the preceding claims, characterized in that the data exchange system is a semantic data communication system in the form of semantic messages.

4. Data exchange system according to one of the preceding claims, characterized in that the data exchange system is an “edge cloud” type system.

5. Method for exchanging semantic data between at least one semantic data transmitter (10) and a semantic data receiver (13) via a transmission channel (12), characterized in that it comprises at least the following steps: - A semantic interpretation control module controls the interpretation used to interpret the semantic data, - If the interpretation is correct, then the semantic data is transmitted (24), - If the interpretation of the data is incorrect, the semantic interpretation control module transmits (25) information to the transmitter so that the semantic data generation module generates new semantic data (26) before retransmission (27) to the receiver.

6. Method according to claim 5 characterized in that the semantic data generation module uses data from a knowledge database to generate new semantic data.

7. Method according to one of claims 5 or 6 characterized in that the step of controlling the semantic interpretation uses knowledge graphs in order to detect the semantic similarity or the equivalent similarity of the semantic data.

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