BLE communication between a vehicle remote key box and a vehicle

Abstract

BLE Communication Between a Vehicle Remote Key Housing and a Vehicle A method for communication between a vehicle remote key housing and a vehicle is proposed. The key housing is configured to perform Bluetooth Low Energy, BLE, communications with the vehicle. The method comprises a first communication phase (S1) between the key housing and the vehicle, the first communication phase being performed according to an original 1M PHY modality; a provision (S2) to the key housing of an exchange command between the key housing and the vehicle; and following the command, a second communication phase (S4) between the key housing and the vehicle, the second communication phase being performed according to a coded PHY modality or a 2M PHY modality. This constitutes an improved solution for communication between a vehicle remote key housing and a vehicle. [Fig. 1]

Description

Title of the invention: BLE communication between a vehicle remote key box and a vehicle Technical field

[0001] The disclosure relates to a method of Bluetooth Low Energy (BLE) communication between a vehicle remote key housing and a vehicle, as well as a vehicle remote key housing configured for such a communication method. Technical background

[0002] Vehicle remote control key boxes, often called "identifiers" or "keyfobs" in English, are particularly energy-intensive due in particular to their BLE communications with a vehicle. Given the compactness and lightness sought for these boxes, the batteries integrated therein generally have a limited capacity. In order to maintain a relatively long battery life, for example of the order of at least two years, BLE communications between the key box and the vehicle are usually carried out according to the original PHY IM modality of the BLE protocol. However, the characteristics of the communication according to this modality are limited, in particular with regard to the range of the communication and / or its flow rate.

[0003] Thus, there is a need for an improved BLE communication solution between a vehicle remote key box and a vehicle. Summary

[0004] To this end, a method is proposed for communication between a vehicle remote control key housing and a vehicle. The key housing is configured to carry out Bluetooth low energy, BLE, communications with the vehicle. The method comprises a first communication phase between the key housing and the vehicle. The first communication phase is carried out according to an original IM PHY mode. The method further comprises providing the key housing with an exchange command between the key housing and the vehicle. The method also comprises, following the command, a second communication phase between the key housing and the vehicle. The second communication phase is carried out according to a coded PHY mode or a 2M PHY mode.

[0005] According to a first variant, the command may consist of a request to the key box to send a remote instruction to the vehicle. The second communication phase comprises sending the remote instruction from the key box to the vehicle according to the coded PHY mode. The command may for example be provided to the key housing by actuating a button on the key housing, such as a push button.

[0006] Optionally for this first variant, the method may comprise an evaluation of whether or not the key housing is sufficiently close to the vehicle to send the remote instruction according to the original PHY IM modality. Sending the remote instruction from the key housing to the vehicle according to the encoded PHY modality follows a negative result of the evaluation. The key housing is configured to otherwise send the remote instruction from the key housing to the vehicle according to the original PHY IM modality.

[0007] Optionally for this first variant, the evaluation may be based on a set of measurements indicative of the presence or absence of a received signal, the strength of a received signal, and / or an error rate of a frame exchange according to the original PHY IM modality. Each measurement is carried out during the first communication phase.

[0008] According to one embodiment, the command may occur before the end of the first communication phase and while no BLE connection is established between the key box and the vehicle. The first communication phase comprises, following the command, a sub-phase of sending one or more signals from the key box to the vehicle according to the original PHY IM modality. The set of measurements comprises one or more measurements carried out during the sending sub-phase. The evaluation provides a negative result following an indication, by the set of measurements, of an absence of signal received by the key box, in response to the sending of one or more signals from the key box, or, of a lower strength of a signal received by the key box from the vehicle, in response to the sending of one or more signals from the key box compared to a predetermined threshold.

[0009] According to another embodiment, the command may occur after the start of the first communication phase and while a BLE connection is established between the key box and the vehicle. The first communication phase comprises, before the command, a sub-phase of exchanging one or more frames between the key box and the vehicle according to the original PHY IM modality. The set of measurements comprises one or more measurements carried out during the exchange sub-phase.

[0010] In an example of this alternative embodiment, the one or more measurements performed during the exchange sub-phase include one or more measurements of the strength of a signal received by the key housing from the vehicle, and / or one or more measurements of any one or any combination of the following parameters: a number of packets received, a number of events or frames initiated, a number of failed redundancy checks, a number of resend attempts, a number of missed connection events, and / or a data transmission rate.

[0011] According to a second variant, the command may consist of a request to the key box to download an update from the vehicle. The second communication phase comprises a download of the update by the key box from the vehicle according to the PHY 2M mode.

[0012] Optionally for this second variant, the method may comprise an evaluation of whether or not the key housing is inside the vehicle. The download follows a positive result of the evaluation. The key housing is configured to otherwise not initiate the download. According to one example, the evaluation may be an evaluation of whether or not the key housing is stationary inside the vehicle.

[0013] Also provided is a vehicle remote key housing configured to perform BLE communications with a vehicle. The key housing is configured to communicate with the vehicle according to the proposed method. The key housing may be configured to communicate with the vehicle according to any one or both of the proposed variants, according to one or more, for example each, of the options provided for each respective variant, and / or according to one or both of the proposed embodiments for an option of the first variant.

[0014] Also provided is a computer program comprising instruction code configured, when executed by a vehicle remote key housing, to perform the proposed method with a vehicle. The program may be installable on a memory of a vehicle remote key housing already configured to perform BLE communications with a vehicle, and the program may thus add a configuration to the key housing making it capable of communicating with the vehicle according to the proposed method. The computer program may comprise instruction code configured to perform the method according to any one or both of the proposed variants, according to one or more, for example each, of the options provided for each respective variant, and / or according to one or both of the proposed embodiments for an option of the first variant.

[0015] Also provided is a computer program comprising instruction code configured, when the code is executed by a vehicle, to perform the method according to the proposed method with a vehicle remote key housing. The program may be installable on a memory of a vehicle already configured to perform BLE communications with a vehicle remote key housing, and the program may thus add a configuration to the vehicle making it capable of communicating with the vehicle remote key housing according to the proposed method. The computer program may comprise instruction code configured to perform the method according to any one or both of the proposed variants, according to one or more, for example each, of the options provided for each variant respective, and / or according to one or both of the embodiments proposed for an option of the first variant. Brief description of the figures

[0016] Non-limiting examples will be described with reference to the following figures:

[0017] [Fig. 1] shows the proposed method of communication between a TV key box vehicle control and a vehicle, where the order of steps as shown in the diagram is not necessarily representative of the actual timeline.

[0018] [Fig.2] shows a vehicle remote key housing configured to perform BLE communications with a vehicle.

[0019] [Fig.3] shows an embodiment of an example of the first variant of the method.

[0020] [Fig.4] shows another embodiment of an example of the first variant of the method.

[0021] [Fig.5] illustrates several situations of application of the method according to the embodiments of figures 3 and 4.

[0022] [Fig.6] shows a progressive degradation of the signal.

[0023] [Fig.7] shows an example of the second variant of the method. Detailed description

[0024] [Fig. 1] shows a method of communication between a vehicle and a vehicle remote control key housing (also known as "identifier", or "keyfob", a commonly used English term). The key housing is configured to carry out BLE communications with the vehicle. The method comprises a first communication phase SI between the key housing and the vehicle. The first communication phase SI is carried out according to an original PHY IM modality. The method further comprises a supply S2 to the key housing of an exchange command between the key housing and the vehicle. The method also comprises, following the command, a second communication phase S4 between the key housing and the vehicle, the second communication phase being carried out according to a coded PHY modality or a 2M PHY modality.

[0025] Such a method constitutes an improved solution for BLE communication between a vehicle remote key box and a vehicle.

[0026] BLE communications allow for relatively long-range, low-power remote exchanges. These exchanges make it possible to anticipate or remotely activate functionalities, for example to send commands to the vehicle from the key box. Since the first communication phase S1 is carried out using an original PHY IM mode, it is particularly energy-efficient. The key box can be configured to communicate by default using this original PHY IM modality when communicating in BLE with the vehicle, so it aims to consume as little energy as possible.

[0027] The possibility according to the method of providing in S2 a given exchange command between the key box and the vehicle, and following this, the fact for the key box to engage a second communication phase S4 with the vehicle which is carried out according to a coded PHY modality or a 2M PHY modality, makes it possible to respond to the limitations of the original PHY IM modality. In particular, the original PHY IM modality has a limited range. The coded PHY modality makes it possible to increase this range, and thus for example to send a command to the vehicle at a distance where this would be impossible or difficult according to the original PHY IM modality. Furthermore, the original PHY IM modality has a limited throughput. The 2M PHY modality makes it possible to increase the throughput, for example when a faster exchange of a large quantity of data is desired.The dynamic switching from the original IM PHY mode to the coded PHY mode or the 2M PHY mode thus allows optimization of the exchanges ordered from the key box, by optimally exploiting different possible BLE communication modes.

[0028] [Fig. 2] shows a vehicle remote control key housing 20 configured to perform BLE communications with a vehicle 30, the key housing 20 being configured to communicate with the vehicle 30 according to the method of [Fig. 1].

[0029] The vehicle 30 may be an automobile, a motorcycle, a truck, or more generally any land vehicle. The vehicle comprises a BLE transceiver, configured to carry out BLE exchanges with the key box 20. The vehicle 30 and the key box 20 may have been previously paired (according to the BLE protocol), in order to allow these exchanges.

[0030] The vehicle remote control key housing 20, or "identifier", may comprise a protective housing 22 encompassing components of the key housing 20. The protective housing 22 may comprise plastic material, metallic material and / or rubber plastic material. The key housing 20 may comprise a logo 23, for example made of metal. The logo may be arranged on the outer casing of the protective housing 22, and / or the logo may represent a manufacturer's brand. The logo disrupts BLE communications, and thus the logo may contribute to causing certain BLE communications carried out according to the original PHY IM modality to fail when they are carried out too far away between the key housing 20 and the vehicle 30.The key housing 20 may comprise inside the protective housing 22 a metal insert 24, which makes it possible to open and / or start the vehicle 30 manually, by inserting and manipulating the insert in a respective lock of the vehicle 30. The metal insert 24 also disrupts BLE communications.

[0031] The key box 20 comprises at least one BLE transceiver 26, configured to carry out BLE exchanges with the vehicle 30. The transceiver 26 may comprise or consist of an electronic microchip, comprising a microprocessor and an antenna adapted to BLE communication. The microprocessor may have in memory a computer program allowing BLE communications, and to carry out different specific functionalities such as for example initiating the second communication phase S4.

[0032] In particular, the transceiver 26 may be configured to perform BLE exchanges not only according to the original PHY IM modality of the BLE protocol, but also according to the coded PHY modality and / or the PHY 2M modality of the BLE protocol. Thus, the key box 20 may be such that the same transceiver 26 performs both the exchanges occurring in SI and the exchanges occurring in S4. This provides better compactness of the key box 20 and reduces the number of components. Alternatively, the function of the transceiver 26 may be limited to exchanges according to the original PHY IM modality, and the key box 20 may comprise at least one additional transceiver for exchanges according to the coded PHY modality and / or the PHY 2M modality.

[0033] Optionally, the key box 20 may be configured to, in addition to being able to communicate according to the original IM PHY modality, be able to communicate according to both the coded PHY modality and the 2M PHY modality. Thus, the method may be repeated, with at least one repetition where the communication in S4 is done according to the coded PHY modality, and one repetition where the communication in S4 is done according to the 2M PHY modality. The method may include a selection of the modality for S4 depending on the nature of the command provided in S2. The key box 20 is thus configured to dynamically switch between different PHY modalities depending on the situation, the original IM PHY modality serving as a pivot. Subsequently, examples of the method where the communication in S4 is done according to the coded PHY modality, and examples of the method where the communication in S4 is done according to the 2M PHY modality, are provided.The method may be repeated to achieve any combination of these examples, e.g., each of these examples. Accordingly, the key housing 20 may be configured to communicate with the vehicle 30 according to any one of these examples depending on the situation, e.g., each of these examples depending on the situation.

[0034] The key housing 20 also comprises a battery 28, which makes it possible to supply power to its components, in particular at least one transceiver of the key housing 20 including the transceiver 26, for example each transceiver of the key housing 20. The battery 28 may be a button cell and / or a voltage of 3V or a voltage between IV and 10V.

[0035] The key housing 20 may optionally comprise a UWB transceiver (acronym for “Ultra Wide Band”). Large »), configured to carry out UWB exchanges with the vehicle 30. The UWB transceiver may comprise or consist of an electronic microchip, comprising a microprocessor and an antenna adapted to UWB communication. The microprocessor may have in memory a computer program enabling UWB communications, and to carry out various specific functionalities such as for example enabling the vehicle 30 to locate the key housing 20. The vehicle 30 may indeed optionally comprise UWB anchors, each comprising a transceiver adapted to calculate the distance from the key housing 20 via UWB exchanges.

[0036] The key housing 20 may also optionally comprise a motion sensor, configured to detect movements of the key housing 20. Such detections make it possible to manage the BLE communications of the key housing 20 with the vehicle 30. For example, a stationary key housing 20 may stop or reduce the frequency of any BLE signal sending, at least in certain situations. In this case, a movement imparted to the initially stationary key housing 20 and detected by the motion sensor may initiate or accelerate a sending of BLE signals, for example in order to attempt to reestablish a BLE connection with the vehicle 30.

[0037] The "Bluetooth Low Energy" or "Bluetooth Low Energy" protocol (corresponding to the acronym BLE or BTLE) is the communication standard usually used for communications involving an exchange of data between a vehicle remote control key box and a vehicle, for example so that the key box transmits remote commands to the vehicle, and / or so that the vehicle transmits update data to the key box. The standard makes it possible to implement different "PHY" communication methods at the physical layer of the protocol. The name PHY is an abbreviation of the English "Physical layer", which means "physical layer".

[0038] As is now widely known, the "original IM PHY" modality offers a rate of 1 Mega symbols / second, where each data bit is represented by 1 symbol, which gives 1 Mbps. The "coded PHY" modality also offers a rate of 1 Mega symbols / second, where each data bit is represented by several symbols, for example 2 or 8 symbols, which gives 500 Kbps or 125 Kbps. Compared to the original IM PHY modality, the coded PHY modality allows, thanks to the coding, to operate a different modulation resulting in a longer range, at the cost of increased energy consumption. The "2M PHY" modality offers a rate of 2 Mega symbols / second, where each data bit is represented by 1 symbol, which gives 2 Mbps. Compared to the original IM PHY modality, the 2M PHY modality allows for higher throughput, also at the cost of increased power consumption.

[0039] Therefore, the original PHY IM modality is the preferred modality for implementing BLE exchanges between the vehicle key box and the vehicle, because it allows the battery life to be preserved as much as possible, while maintaining a range of several tens of meters to control the vehicle, which is generally satisfactory. However, there may be occasional situations where the coded PHY mode allowing a longer range may be useful, for example for certain remote commands that one wishes to carry out at a distance beyond 100 meters or even 250 meters. There may also be occasional situations where the 2M PHY mode allowing a higher throughput may be useful, for example for certain exchanges of large quantities of data that one wishes to carry out as quickly as possible, in particular during a software update of the key box.

[0040] With reference to Figures 1 and 2, such situations may arise following a particular exchange command between the key housing 20 and the vehicle 30 provided to the key housing 20, in particular in step S2. This is understood to mean any action performed on the key housing 20 so that the key housing 20 performs a BLE communication exchange with the vehicle 30. The command may be physical, thus involving a physical operation on the key housing 20. In particular, the key housing 20 may comprise one or more buttons each operable. A command may thus be provided to the key housing 20 by actuation of at least one such button. The one or more buttons may in particular comprise one or more push buttons, operable by pressure.The key housing 20 may be configured to receive at S2 a command by actuation of a single button, for example pressing a single push button, and / or to receive at S2 a command by actuation of several buttons, for example each by pressing a respective button, for example simultaneously or according to a predetermined sequence. Alternatively or additionally, the command may be provided at S2 to the key housing 20 via a signal. For example, the key housing 20 may receive from the vehicle an update request signal, corresponding to an update launch command.

[0041] Thus, during the method, the key box 20 is initially in a first BLE communication mode according to the original IM PHY modality, and the key box 20 carries out in SI a communication with the vehicle 30 according to this first mode. Following S2, and possibly the evaluation of certain conditions, the key box 20 switches to a second communication mode according to the coded PHY modality or the 2M PHY modality, and it thus sends any signal in S4 according to this second mode. Step S4 may in particular comprise an establishment of a BLE connection according to the coded PHY modality or the 2M PHY modality with the vehicle, then, once the connection is established, an exchange of “useful” frames according to the coded PHY modality or the 2M PHY modality with the vehicle. By “useful” frame, we mean a frame aiming beyond an establishment or maintaining a connection, for example aimed at transmitting to its interlocutor a command to be executed (eg, and resulting in physical actuation of vehicle equipment) or information to be recorded in non-volatile memory.

[0042] Examples of the method according to the first variant (and corresponding configuration of the key box 20) where the second communication phase S4 is carried out according to the coded PH Y modality are now described.

[0043] According to the first variant, the command provided in S2 may consist of a request to the key box 20 to send a remote instruction to the vehicle 30. The second communication phase S4 may then comprise sending said instruction from the key box 20 to the vehicle 30, this sending being carried out according to the coded PHY mode. Thus, the ability to switch from the original IM PHY mode to the coded PHY mode allows sending a remote instruction according to a modality having a longer range.

[0044] During step S2, the key housing 20 may be carried and / or manipulated by a user located at a distance from the vehicle, the user initiating a remote instruction using the key housing 20. The command may be provided by actuating a button on the key housing 20 as described previously, for example by pressing a push button. The vehicle may be empty of any person during step S2.

[0045] According to the method, the instruction is sent in S4 according to the coded PHY mode. For this, the key box S20 can switch from its original default PHY IM mode to a coded PHY mode that it supports. This makes it possible to better reach the vehicle and thus for the latter to carry out the instruction, even if the key box 20 is located at a long distance from the vehicle. For example, the user and / or the box may be located at a distance greater than 100 meters, or even greater than 250 meters, or even greater than 1 kilometer, from the vehicle 30, which would make it difficult or even impossible to successfully send the instruction according to the original PHY IM mode used by default.

[0046] The remote instruction may be any one of a predetermined list of one or more remote instructions for which the key housing 20 supports such a functionality of switching from the original IM PHY mode to the longer range encoded PHY mode. The predetermined list may include a lock instruction, allowing the vehicle to be remotely locked, a remote start instruction, allowing the engine to be remotely started from outside the vehicle, in order to preheat it, a preconditioning instruction, allowing air conditioning or heating of the vehicle from outside the vehicle, and / or a hazard instruction, allowing the vehicle to be remotely sounded, for example in the event of a panic or hazard situation.Such functions are useful to be able to activate remotely by the user, even at distances. too large for the original PHY IM. The predetermined list can exclude any vehicle unlocking instructions, to avoid the risk of a third party entering the vehicle when it has been unlocked too far away to prevent it.

[0047] According to an example, the method may comprise an evaluation of whether or not the key housing 20 is sufficiently close to the vehicle to send the remote instruction according to the original PHY IM modality. This evaluation may be carried out by a microprocessor of the key housing 20, for example the microprocessor of the transceiver 26. The remainder of the method may be conditioned on this evaluation. In particular, the sending of the remote instruction from the key housing 20 to the vehicle 30 according to the coded PHY modality follows a negative result of the evaluation. And the key housing 20 is configured to otherwise send the remote instruction from the key housing 20 to the vehicle 30 according to the original PHY IM modality.In other words, the key box 20 is configured to, upon receipt of the command S2: i) optionally check whether the commanded remote instruction belongs to the predetermined list, for example by a microprocessor of the key box 20, such as the microprocessor of the transceiver 26, ii) evaluate whether or not the key box 20 is sufficiently close to the vehicle, iii) if so, send the instruction according to the original IM PHY modality, otherwise send the instruction according to the coded PHY modality.

[0048] Thus, the overconsumption of the battery 28 caused by the switch to the coded PHY mode is limited to only those cases where this is necessary, which optimizes the lifetime of the battery 28. Furthermore, this allows a reaction of the vehicle 30 to a remote instruction sent by the key box 20 that is uniform between the instructions belonging to the predetermined list and those not belonging to it, in the case where the key box 20 is sufficiently close to the vehicle, and where the user therefore potentially sees the reaction of the vehicle directly following S2. The original IM PHY mode and the coded PHY mode in fact have significantly different signal characteristics, so that the reactivity of the vehicle is not the same depending on whether the same instruction is sent to it from the same key box, located at the same position, but according to one or other of the two modes.Using the coded PHY mode only when necessary, i.e. at a sufficiently long distance, makes it possible to avoid different visible behaviors of the vehicle depending on the instruction given to it, in terms of reaction time, which is undesirable from an ergonomic point of view for the user.

[0049] The evaluation ii) may be based on a set of measurements indicative of the presence or absence of a received signal, the strength of a received signal, and / or an error rate of a frame exchange according to the original PHY IM modality, each measurement being carried out by the key box 20 during the first communication phase. S2. Thus, the key box 20 measures during the first communication phase S2 whether the connection exists and / or is good enough to maintain the original IM PHY mode. Otherwise, the key box 20 switches to the coded PHY mode, in order to increase the chances of successfully communicating with the vehicle during the second communication phase S4.

[0050] [Fig.3] illustrates an embodiment of such an example of the first variant of the method, where an exchange command between the key box and the vehicle and which consists of a request to the key box to send to the vehicle a remote instruction as described above is provided in S20 to the key box, while no BLE connection is established between the key box and the vehicle.

[0051] In this embodiment, the method comprises a first sub-phase S12 of the first communication phase between the key box and the vehicle. By "sub-phase" is meant a part of the first communication phase. This sub-phase S12 is carried out according to an original PHY IM modality. At any time and for any reason, a loss S14 of the BLE connection occurs. This loss S14 of connection may for example occur because the user has moved away from his vehicle beyond the BLE range of the original PHY IM modality for a time greater than a predetermined duration, and / or because the key box has remained stationary outside the vehicle (which can be detected on the basis of measurements of the optional motion sensor) for a time greater than a predetermined duration, optionally while the last exchange command provided to the box was to send the vehicle an instruction to lock the vehicle.

[0052] Subsequently, the method comprises a provision S20 to the key housing of an exchange command between the key housing and the vehicle, consisting of a request to the key housing to send to the vehicle a remote instruction, as described previously.

[0053] Following this command provided in S20, the method comprises a sending S16 of one or more signals from the key box to the vehicle according to the original PHY IM modality. This sending S16 being carried out according to the original PHY IM modality, it can be considered as being a second sub-phase of the first communication phase. In the absence at this moment of a BLE connection established between the key box and the vehicle, this sending S16 can comprise so-called “advertising signals” aimed at establishing a BLE connection according to the original PHY IM modality with the vehicle. According to known protocols, the vehicle can respond to such an advertising signal with a scan request. Alternatively, the vehicle may have actively sent a scan request, and the sending S16 can consist of responding to it with a scan signal. advertisement.

[0054] The method then comprises an evaluation S30 of whether or not the key box is close enough to the vehicle to send the remote instruction according to the original PHY IM modality. This evaluation S30 is in this case carried out on the basis of measurements carried out by the key box during S16. In particular, the key box can analyze whether it is indeed receiving one or more scanning requests in response to its advertising signal(s), or one or more active scanning requests, which indicates the presence within range of the vehicle. If applicable, the key box can further analyze the strength of such “scan request” signals received by the box. This can consist of one or more RSSI measurements (acronym for “Received Signal Strength Indication”) carried out on any scanning requests received.The method may include a comparison between the measured force and a predetermined threshold. If the force (e.g. RSSI measurement) is below the predetermined threshold, it may be inferred that the vehicle is too far away for proper originating PHY IM communication.

[0055] Thus, following the evaluation S30, if this concludes that there is no vehicle detected within range, or that the vehicle is too far away even if detected, the method may comprise a switch to coded PHY mode and a sending of the remote instruction by the key box to the vehicle according to the coded PHY mode. The probability that the remote instruction is received from the vehicle is thus increased.

[0056] If, on the other hand, the S30 evaluation concludes that the vehicle is sufficiently close to send the instruction in the original PHY IM, then the box will actually use this mode by default in order to preserve the battery and not disturb the user.

[0057] [Fig.4] illustrates another embodiment of such an example of the first variant of the method, where an exchange command between the key box and the vehicle and which consists of a request to the key box to send to the vehicle a remote instruction as described above is provided in S20 to the key box, while a BLE connection is established between the key box and the vehicle.

[0058] A BLE connection being established, the key box and the vehicle exchange S12' frames periodically according to the original PHY IM modality, in order to maintain the connection, as generally known from the BLE protocol, for example every 50 milliseconds or every 100 milliseconds, depending on the BLE protocol option chosen. The method may comprise carrying out S32' one or more measurements during this exchange S12', for example in the background. Indeed, these BLE exchanges carried out periodically, for example with a period of less than 1 second or less than 500 milliseconds, directly provide the appropriate information to the decision based on the S34' evaluation to send in S40 the instruction according to the original IM PHY mode or to switch to the coded PHY mode instead.

[0059] At the precise instant of the provision S20 of the instruction to be sent, the key box can base its evaluation S34' on past measurements (i.e., carried out in S32' over a period close in the past, for example over a duration having started less than 5 seconds or 2 seconds before the detection of the provision S20) and / or on present measurements (i.e., measurements S33' in progress or to be carried out in a very close time, ending before 1 second or 500 milliseconds immediately following the detection of the provision S20). Using past measurements makes it possible to use more measurements, for example all the measurements over a period of time greater than 500 milliseconds or 1 second, and thus to base the evaluation S34' on an evolution of the measurements, making it more robust to one-off artifacts and noise. Using existing measurements in addition allows the S34' assessment to be refined, as existing measurements are the most representative of what is to be anticipated.

[0060] The measurements may relate to one or more metrics together indicative of the strength of a received signal, and / or of an error rate of a frame exchange. Each metric may be a function of one or more parameters, and each parameter may give rise to several measurements spaced in time. A metric may thus have a point value, corresponding to the measurement(s) made at a given time to calculate the metric, or an averaged value, because if several measurements spaced in time are available for a respective parameter of a given metric, then an average of the metric may be calculated.

[0061] The evaluation S34' may correspond to the verification that one or more metrics, or a formula based on the metrics, exceeds or does not exceed a predetermined threshold, punctually and / or on average (the threshold may be different depending on whether one is looking at a punctual or averaged metric). The evaluation S34' may thus be carried out in any manner as long as it tends to carry out the switch to the coded PHY mode when the original IM PHY connection appears degraded in view of the measurements.

[0062] In particular, the one or more measurements on which the evaluation S34' is based may comprise one or more measurements of the strength of a signal received by the key box from the vehicle (for example RSSI measurement). In other words, the evaluation S34' is based on the strength or RSSI of the frames received from the vehicle during the exchanges in original IM PHY during the existing connection, for example the exchanges carried out periodically to maintain the existing connection. A decrease in the strength or RSSI indicates a degradation of the connection, and thus favors a sending in S40 in coded PHY.

[0063] Alternatively or additionally, the one or more measures on which the S34' assessment is based may comprise one or more measurements of any or any combination of (eg, all of) the following parameters relating to a packet error rate, taken over a predetermined duration. In particular, the one or more measurements may comprise RSSI, which makes it possible to simply determine whether the connection is good or bad, and the S34' assessment may be advantageously refined by additional measurements available from the BLE exchange according to the current IM PHY modality.

[0064] With reference to the Bluetooth protocol, the method can measure, in the first category of parameters relating to a packet error rate, a number of packets (correctly) received and / or a number of events or frames (correctly) initiated. The higher the value of this or these parameters, in particular compared to the parameters of the second category of parameters, the more this indicates a stable original PHY IM connection which can therefore be maintained. The method can also measure, in the second category of parameters relating to a packet error rate, a number of failed redundancy checks, a number of repeated sending attempts, and / or a number of missed connection events. The lower the value of this or these parameters, in particular compared to the parameters of the first category of parameters, the more this indicates a stable original PHY IM connection which can therefore be maintained.The method can also measure, in a third category of parameters relating to a packet error rate, a transmission rate of "useful" data or frames, in the sense defined previously, when such exchanges take place. The higher this rate, the more this indicates a stable original PHY IM connection which can therefore be maintained.

[0065] The method can continuously and in the background calculate any metric (i.e., statistic) representative of signal stability, such that in case of stability below a predetermined threshold, the connection is evaluated in S34' as being bad, such that the remote instruction is sent in S40 in coded PHY mode. For example, the method can continuously and in the background during the exchanges of original BLE PHY IM frames measure and monitor the RSSI, as well as one or more metrics each representative of a packet error rate, and each calculated from one or more of the measured and listed parameters.The method can continuously and in the background average these measurements over a sliding time window comprising frame exchanges, and the evaluation S34' can conclude that the distance is too great to send the remote instruction in the original BLE PHY IM as soon as the RSSI or one of the metrics exceeds a respective first predetermined threshold, and / or as soon as several of the RSSI and the metrics each exceed a respective second predetermined threshold. In the case where both conditions are evaluated, each second predetermined threshold can be lower than its first predetermined threshold. respective. This represents the fact that if a single metric is very bad, namely beyond a criticality level (first predetermined threshold), then this can immediately disqualify the use of the original PHY IM, but if a single metric is bad (second predetermined threshold), but below a certain criticality level (first predetermined threshold), this can be acceptable as meaning an isolated indicator of bad signal, whereas if several metrics are bad (second predetermined threshold) this is no longer acceptable even if each is below the criticality level (first predetermined threshold).

[0066] [Fig. 5] illustrates several situations where the embodiments of Figures 3 and 4 find their utility. In each situation, the key housing 20 is carried by a user in a position P1, P2, P3 or P4, and the user actuates it in order to send a remote instruction to the vehicle 20. The figure illustrates the range 52 of communications according to the original BLE PHY IM modality, as well as the greater range 54 of communications according to the coded BLE PHY modality.

[0067] If the key box 20 is located in position PI during provision S20, i.e., well within range 52, then the RSSI signal received by the key box 20 from the vehicle is high. Furthermore, a BLE connection is probably established, and the metrics also indicate a low packet error rate. Therefore, the sending of the remote instruction is performed according to the original BLE PHY IM modality (i.e., neither S30 nor S34').

[0068] If, on the other hand, the user moves away and the key box 20 is located in position P2 during the provision S20, i.e. at the limit of the range 52, then the RSSI signal received by the key box 20 from the vehicle has gradually decreased over a predetermined period of time that has passed and has just elapsed, and / or the metrics indicate a packet error rate that increases over a predetermined period of time that has passed and has just elapsed. Therefore, the sending of the remote instruction can be carried out according to the coded BLE PHY modality, depending on the situation (i.e., S34' possible). If the user was actually approaching the vehicle 30 when he reached P2 and operated the key box 20, and / or remained in P2 for some time, then the received RSSI signal was previously low and the packet error rate high, so that in this case the sending of the remote instruction is most likely performed according to the BLE PHY encoded modality (i.e., S34' very likely).

[0069] If the key housing 20 is located in position P3 when providing S20, i.e., well out of range 52 but well within range 54, then a signal is indeed received from the car, but the RSSI is low. Since the connection is probably absent, packet error rate metrics are not available. Sending the remote instruction is most likely done in the encoded BLE PHY modality (i.e., S30 very likely), and it is likely that the vehicle receives correctly instruction.

[0070] If the key housing 20 is located in position P4 when supplying S20, i.e. well outside the range 54, then no signal is received from the car. Sending can still be done in coded BLE PHY, but it is unlikely that the vehicle will correctly receive the instruction, unless the user were to move towards the inside of the range 54.

[0071] [Fig.6] shows a progressive degradation of the signal, corresponding to the situation where a user moves away from the vehicle from the original BLE PHY IM range.

[0072] Examples of the method according to the second variant (and corresponding configuration of the key box 20) where the second communication phase S4 is carried out according to the PHY 2M modality are now described.

[0073] According to the second variant, the command provided in S2 may consist of a request to the key box to download an update from the vehicle. The second communication phase S4 may then comprise a download of the update by the key box from the vehicle according to the PHY 2M mode.

[0074] [Fig.7] shows an embodiment of this second variant. In this embodiment, the method comprises a first communication phase S100 between the key housing and the vehicle, carried out according to an original PHY IM modality, for example because a user approaches the vehicle, unlocks it and enters it. The method then comprises the positioning SI 10 of the key housing in a stationary manner inside the vehicle, for example because the user places the keys in a storage space inside the vehicle. The method then comprises a provision S200 to the key housing, via a signal sent by the vehicle according to the original PHY IM modality, of a request to download a software update. The method comprises by the key housing an evaluation S300 of whether or not the key housing is stationary and inside the vehicle.This can be achieved using the key case's optional UWB transceiver and optional vehicle UWB anchors and / or the key case's optional motion sensor. Following a positive evaluation in S300, the S400 download can be initiated in PHY 2M so that it is performed faster than if it were done in the original PHY IM (for the same amount of update information). The key case can be configured so that, if the S300 evaluation is negative, not to initiate the download, and thus wait for a new opportunity.

Claims

Claims

1. A method of communication between a vehicle remote control key box (20) and a vehicle (30), the key box being configured to carry out Bluetooth low energy, BLE, communications with the vehicle, the method comprising: • a first communication phase (S1, S12-S16, S12', S100) between the key box and the vehicle, the first communication phase being carried out according to an original IM PHY modality; • a supply (S2, S20, S200) to the key box of an exchange command between the key box and the vehicle; and • following the command, a second communication phase (S4, S40, S400) between the key box and the vehicle, the second communication phase being carried out according to a coded PHY modality or a 2M PHY modality.

2. Method according to claim 1, in which the command consists of a request to the key housing to send to the vehicle a remote instruction, the second communication phase comprising a sending (S20) of the remote instruction from the key housing to the vehicle according to the coded PHY modality, the command being optionally provided to the key housing by actuation of a button of the key housing, for example a push button.

3. The method of claim 2, wherein the method comprises evaluating (S30, S32'-S34') whether or not the key housing is sufficiently close to the vehicle to send the remote instruction according to the original PHY IM modality, sending (S20) the remote instruction from the key housing to the vehicle according to the encoded PHY modality following a negative result of the evaluation, the key housing being configured to otherwise send the remote instruction from the key housing to the vehicle according to the original PHY IM modality.

4. A method according to claim 3, wherein the evaluation (S30, S32'-S34') is based on a set of measurements indicative of the presence or absence of a received signal, the strength of a received signal, and / or an error rate of a frame exchange according to the original PHY IM modality, each measurement being carried out during the first phase of communication.

5. Method according to claim 4, wherein the command (S20) occurs before the end of the first communication phase (S12-S16) and while no BLE connection is established between the key box and the vehicle, the first communication phase comprising, following the command (S20), a sub-phase of sending (S 16) one or more signals from the key box to the vehicle according to the original PHY IM modality, the set of measurements comprising one or more measurements carried out during the sending sub-phase (S 16), the evaluation (S30) providing a negative result following an indication by the set of measurements of an absence of signal received by the key box in response to the sending of one or more signals from the key box, or of a lower strength of a signal received by the key box from the vehicle in response to the sending of one or more signals from the key box compared to a predetermined threshold.

6. Method according to claim 4, in which the command (S20) occurs after the start of the first communication phase and while a BLE connection is established between the key box and the vehicle, the first communication phase comprising, before the command, a sub-phase of exchange (S12') of one or more frames between the key box and the vehicle according to the original PHY IM modality, the set of measurements comprising one or more measurements (S32') carried out during the exchange sub-phase (S 12').

7. The method of claim 6, wherein the one or more measurements performed during the exchange sub-phase comprise one or more measurements of the strength of a signal received by the key box from the vehicle, and / or one or more measurements of any one or any combination of the following parameters: • a number of packets received, • a number of events or frames initiated, • a number of failed redundancy checks, • a number of resend attempts, • a number of missed connection events, and / or • a data transmission rate.

8. The method of claim 1, wherein the command consists of a request (S200) to the key box to download an update from the vehicle, the second communication phase comprising a download (S400) of the update by the key box from the vehicle according to the PHY 2M mode.

9. The method of claim 8, wherein the method comprises an evaluation (S300) of whether or not the key housing is inside the vehicle, optionally stationary inside the vehicle, the downloading (S400) following a positive result of the evaluation (S300), the key housing being configured to otherwise not initiate the download.

10. A vehicle remote key housing (20) configured to perform BLE communications with a vehicle (30), the key housing being configured to communicate with the vehicle according to the method of any one of claims 1 to 9.

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