FR3113532A1 - SEMANTIC DATA EXCHANGE SYSTEM WITH A SEMANTIC RETRANSMISSION CHANNEL - Google Patents

Abstract

The invention relates to a system for exchanging semantic data 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 knowledge base BGKS, - A receiver (13) comprising a semantic data interpreter module (14) configured to interpret the semantic data received, and a knowledge base BGKD, - A semantic interpretation control module (15) configured to control the interpretation of the semantic data from the semantic data interpreter module, - A return channel (17) between the receiver and the transmitter, and a return channel (18) between the data control module and the semantic data interpreter module, transmitting an acknowledgment of receipt ACK or NACK generated by the control module ole (15). Figure for the abstract: Fig.1

Description

SEMANTIC DATA EXCHANGE SYSTEM WITH A SEMANTIC RETRANSMISSION CHANNEL

The invention relates to a semantic data exchange system comprising a semantic data retransmission channel in the event of an error in “reading” (interpretation or understanding) of the transmitted semantic data.

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 level of the receiver.

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

It applies in any "semantic communication" system comprising one or more semantic data transmitters, such as a mobile telephone, an intelligent mobile telephone known by the Anglo-Saxon term "Smartphone", a mobile peripheral host known under the English abbreviation for “mobile edge host”, or in systems comprising devices of the Internet of Things or IoT (Internet of Things) type.

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. Communications over the past few decades have focused primarily on how to accurately and efficiently transmit symbols from transmitter to receiver. Today, with the development of next-generation wireless communication systems, such as 5G and beyond, it is necessary to have solutions in communication exchanges to "distill" data (choose useful data for transmission) to enable “reliable cognition” and task performance at the receiver.

The prior art describes various systems for retransmitting messages or data following transmission errors.

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 level, deal with the transmission errors detected at the receiver level which are due to channel errors without thread. These mechanisms do not take into account the "semantic" character of the message.

A few brief reminders relating to the retransmission protocols known from the prior art are set out below.

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

ARQ protocols are used for reliable data transmission in wireless communications. In these protocols, the sender 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 sent back to the data sender. The sender retransmits the message when it has received a negative acknowledgment.

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 verify that the receiver is responding. In the case of a normal transmission, the transmitter will receive a positive ACK acknowledgment for the data and then begin transmission of the next packet. While waiting, the sender is said to be in the "idle" state and is unable to send any further data to that destination.

Another technique is called “Go-Back”. Packets are transmitted without waiting for ACK or NACK acknowledgements, until the sender receives feedback from the receiver. Then, in the event of a transmission error, the transmitter goes back up the sequence numbers of the erroneous packet and retransmits all the packets from this sequence number. This technique is easy to implement, but it also introduces a significant overhead in retransmission, since correctly transmitted packets may need to be retransmitted several times before being delivered to higher layers of the transmission system. In addition, the average connection delay is also higher.

The features required for the “Go-Back-N ARQ” technique are summarized below:

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

The local node maintains a buffer containing all packets that have been sent, but not yet acknowledged,

The receiver at the remote node maintains a record of the highest-numbered packet that was correctly received. This number corresponds to the last acknowledgment packet that it was able to transmit.

Recovering a corrupted package involves three steps:

First, the corrupted packet is discarded at the remote node receiver,

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

The last step is the retransmission of the lost packet(s)

A third retransmission method is "SR ARQ" selective repeat transmission. Packets are transmitted continuously as in the "Go-to-Back" method, but only packets with a negative acknowledgment are retransmitted. The functionalities required to support a selective repetition protocol are the same as those required for the "Go-to-Back" technique with, at the receiver, a buffer of frames which have been received but not yet acknowledged. The recovery of a corrupted packet, using selective repetition known by the English abbreviation "Selective Repeat ARQ" by performing the following four steps:

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

The remote node requests retransmission of the missing packet using a control packet, sometimes called a selective reject,

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

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

The receiver transmits the retransmitted packet and all subsequent in-sequence packets that are held in the receiver's buffer.

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

The techniques known in the prior art do not make it possible to solve the problem of transmission error in semantic communication systems and do not take into account the nature of semantic communication.

The notions of semantic equivalence or semantic similarity are known from the prior art, for example in the Floridi publication. 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.).

The idea of the present invention is to provide a semantic data exchange system, said exchange system comprising a semantic retransmission channel which takes into account the semantic nature of the semantic data exchange and which effectively adapts the information forwarded accordingly.

The invention relates to a semantic data exchange system 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:

- A transmitter comprising a semantic data generator and a BGK _S knowledge base,

- A receiver comprising a semantic data interpreter module configured to interpret the semantic data received, and a knowledge base BGK _D ,

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

- A module for choosing the modifications to be made for the generation of the semantic message,

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

The system may include a data aggregation module MA disposed between the semantic data interpreter module and the semantic interpretation control module.

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

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

- A semantic interpretation control module controls the interpretation of semantic data,

- If the interpretation is correct, then the semantic data is transmitted,

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

The semantic data generation module can use data from a knowledge database to generate new semantic data.

The semantic interpretation control step uses, for example, knowledge graphs to detect semantic similarity or equivalent similarity of semantic data.

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

, a diagram illustrating the semantic communication system according to the invention comprising a retransmission channel,

, an illustration of the steps implemented for the method according to the invention.

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

For example, considering the conversation between three people:

Giulio: "Are you home this weekend?"

Livio: "Emilio, Giulio asks if you are free to play with us this weekend"

Emilio: "No, I'm not available on Saturdays and Sundays"

Livio serves as a semantic channel between Giulio and Emilio. Livio does not accurately convey Giulio's original message to Emilio. However, Emilio is still able to preserve the original meaning of Giulio's message.

There may be “x” symbol transmission errors due to the wireless channel. Nevertheless, there is no semantic failure since Emilio understands the meaning of Giulio's message.

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

There illustrates an example of a semantic communication system according to the invention. A transmitter 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 semantic message 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, ie, 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′.

The system according to the invention comprises a knowledge base BGK _S at the level of the transmitter and a knowledge base BGK _D at the level of the receiver.

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. If the message has been correctly decoded semantically, the message is delivered to its recipient 16.

In the event that the message could not be interpreted correctly, the message interpretation control module transmits via a return channel 18 to the sender 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.

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

To decide on the “retransmission” of a semantic message following an erroneous acknowledgement, the message generator takes into account a semantic interpretation function q_s from the knowledge base of the issuer BGK_Sto generate a message x=gj(w) where gj is a semantic interpretation function with j=1….k forming a semantic interpretation engine.

There 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.

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

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

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.

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

If the interpretation of the semantic message is correct, then a next message can be sent by the sender, 24.

For a semantic message that is incomprehensible at the receiver, and following receipt of the NACK information, the semantic message generation module will generate a new semantic message, 26 and send it to the receiver, 27.

The message interpreter module can suggest an interpretation vector, various options for interpreting the message and associate with each interpretation vector Ii a confidence value w ^′ _i . This confidence value corresponds to a probability that an interpretation is semantically identical to the semantic message sent. The confidence value w ^′ _i can 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 can be used to define modifications in the generation of the semantic message in order to improve the quality of the transmission.

The system can also include an "aggregation of different information" module, MA (dotted on the ) 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 the messages interpreted). When the sequence of semantic messages can be interpreted with more precision, and when the meaning of the sequence of semantic messages can be interpreted, this information is transmitted to the receiver to be used in the control of an erroneous interpretation of the semantic message. When all the semantic messages have been correctly received, the interpretation is correct, the receiver transmits a semantic acknowledgement, ACK-Semantic, to the sender. The sender can then start a new communication, transmit a new message sent by the sender can be received.

When the information is available at the issuer, the knowledge base BGK _S or the knowledge base BGK _D 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 that it has detected to the sender of the semantic message.

It is possible that the semantic message is correct at the level of the emission, but that the interpretation is erroneous at the level of the receiver. This can result from various phenomena that will generate several actions to be taken during the message generation step.

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

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 semantic message interpreted is “Hike, the letters H and k contained in the message received do not correspond to the initial letters F and r. The message cannot be correctly interpreted. For the physical transmission of messages, conventional retransmission mechanisms will be used by sending back acknowledgments on HARQ (Hybrid Automatic Repeat Request) packets. The sender-level message generator does not need to generate a new message semantic or new semantics for the message.

In some cases, the knowledge base at the receiver level will not include the information necessary for a correct interpretation of the message.

When noise or wireless interference did not cause receive errors, the “y” message was successfully decoded. However, if the knowledge base BKG _D of the receiver 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 the retransmission of the semantic message.

The semantic message will be generated again with a "semantic equivalence". The receiver informs the sender by transmitting an erroneous acknowledgment, or NACK, that a new transmission or retransmission of the message is required. The retransmission of a semantic message does not systematically lead to correct reception, i.e., a successful interpretation (without interpretation error) of the semantic message.

If the receiver has a value aggregation module, the semantic retransmission can trigger the transmission of additional messages linked to the previous messages, the latter not necessarily being equivalent semantic messages.

In some cases, there will be a mismatch between the semantic message received 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 interpretation module of the receiver. The incorrect interpretation of the objective of the communication may be due to a semantic communication error or even to an erroneous estimation of the knowledge bases of the sender and/or the receiver. This leads to a bad interpretation of the signal received since the interpretation function q _D selected by the interpretation module of the receiver to interpret the semantic message does not lead to correct semantics or lead to equivalent semantic interpretations. The receiver activates a semantic retransmission to reinforce the receiver's semantic information to solve this problem.

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

The message generator of the sender or of a semantic coder generates a new semantic message taking into account different strategies. The message generator has some freedom to ensure the generation of a semantic message that will be interpreted correctly.

For example, the message generator can generate and transmit messages whose message is more precise or easier to generate (according to a cost function) or even more relevant in relation to the recipient's expectations.

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

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

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

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

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

The message generator may also convey an additional explanation of the purpose of the communication. Misinterpretation of the message by the receiver may result from misunderstanding or misinterpreting the purpose of the communication. If the sender is notified, with a dedicated semantic NACK acknowledgment, the sender can 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.

The explanations that have just been given in the case of a semantic communication system apply in the case of a system of the "egde cloud" type.

The system and the method according to the invention make it possible to improve the exchanges of semantic data within the framework of a system for communicating semantic messages or any system exchanging semantic data.

Claims (7)

Semantic data exchange system 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 minus the following:
- A transmitter (10) comprising a semantic data generator (11) and a knowledge base BGK _S ,
- A receiver (13) comprising a semantic data interpreter module (14) configured to interpret the semantic data received, and a knowledge base BGK _D ,
- 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,
- 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 reception ACK or of incorrect reception NACK generated by the control module (15). Semantic data exchange system according to Claim 1, characterized in that it comprises a data aggregation module MA placed between the semantic data interpreter module (14) and the semantic interpretation control module (15). 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. Data exchange system according to one of the preceding claims, characterized in that the data exchange system is an “edge cloud” type system. 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 sender so that the semantic data generation module generates new semantic data (26) before retransmission (27) to the receiver. Method according to Claim 5, characterized in that the semantic data generation module uses data from a knowledge database to generate new semantic data. 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.