BLE communication between a vehicle key fob and a vehicle

Abstract

The invention relates to a method for communication between a vehicle key fob and a vehicle. The key fob is configured to perform Bluetooth Low Energy, BLE, communications with the vehicle. The method comprises a step (S1) of performing a first communication phase between the key fob and the vehicle, wherein the first communication phase is performed according to an original 1M PHY mode; a step (S2) of providing the key fob with a command for an exchange between the key fob and the vehicle; and, in response to the command, a step (S4) of performing a second communication phase between the key fob and the vehicle, wherein the second communication phase is performed according to an encoded PHY mode or a 2M PHY mode. This constitutes an improved solution for communication between a vehicle key fob and a vehicle.

Description

BLE communication between a vehicle remote key box and a vehicle

[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 fobs, often referred to as "identifiers" or "keyfobs", are particularly energy-intensive, particularly due to their BLE communications with a vehicle. Given the compactness and lightness required for these key fobs, the batteries integrated into them 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 fob and the vehicle are usually carried out using the original 1M PHY mode of the BLE protocol. However, the characteristics of communication using this mode are limited, particularly with regard to the communication range and / or its throughput.

[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 1M 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 housing to send a remote instruction to the vehicle. The second communication phase comprises sending the remote instruction from the key housing 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 1M PHY 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 1M PHY 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 1M 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 housing and the vehicle. The first communication phase comprises, following the command, a sub-phase of sending one or more signals from the key housing to the vehicle according to the original PHY 1M 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 housing, in response to the sending of one or more signals from the key housing, or, of a lower strength of a signal received by the key housing from the vehicle, in response to the sending of one or more signals from the key housing 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 1M 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 includes 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, e.g., 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 thereby 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 thereby 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 respective variant, and / or according to one or both of the proposed embodiments 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] The diagram shows the proposed method of communication between a vehicle remote control key housing and a vehicle, where the order of steps as shown in the diagram is not necessarily representative of the actual timeline.

[0018] Shows a vehicle remote key fob configured to perform BLE communications with a vehicle.

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

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

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

[0022] The watch shows a progressive degradation of the signal.

[0023] Lamontre shows an example of the second variant of the process. Detailed description

[0024] The invention relates to a method for communication between a vehicle and a vehicle remote control key housing (also known as an identifier or a commonly used English term, a keyfob). The key housing is configured to carry out BLE communications with the vehicle. The method comprises a first communication phase S1 between the key housing and the vehicle. The first communication phase S1 is carried out according to an original 1M PHY 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 provides an improved solution for BLE communication between a vehicle remote key box and a vehicle.

[0026] BLE communications enable 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 1M PHY mode, it is particularly energy-efficient. The key box can be configured to communicate by default using this original 1M PHY mode when communicating with the vehicle via BLE, so that 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 mode or a 2M PHY mode, makes it possible to respond to the limitations of the original 1M PHY mode. In particular, the original 1M PHY mode has a limited range. The coded PHY mode 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 1M PHY mode. Furthermore, the original 1M PHY mode has a limited throughput. The 2M PHY mode makes it possible to increase the throughput, for example when a faster exchange of a large quantity of data is desired.Dynamic switching from the original 1M 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] The show 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 the.

[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, metal 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 1M modality to fail when they are carried out at too great a distance 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 housing 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 various 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 1M 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 housing 20 may be such that the same transceiver 26 performs both the exchanges occurring in S1 and the exchanges occurring in S4. This provides better compactness of the key housing 20 and reduces the number of components. Alternatively, the function of the transceiver 26 may be limited to exchanges according to the original PHY 1M modality, and the key housing 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 1M 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 1M PHY modality serving as a pivot. Below, 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 perform 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 1V and 10V.

[0035] The key housing 20 may optionally comprise a UWB (acronym for "Ultra Wide Band") transceiver, 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 allowing UWB communications, and to carry out various specific functionalities such as for example allowing 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 include 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 (BLE or BTLE) is the communication standard commonly used for communications involving the exchange of data between a vehicle remote control key unit and a vehicle, for example so that the key unit transmits remote commands to the vehicle, and / or so that the vehicle transmits update data to the key unit. The standard allows for the implementation of different "PHY" communication methods at the physical layer of the protocol. The term PHY is an abbreviation of the English "Physical layer".

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

[0039] Therefore, the original 1M PHY 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 modality 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 modality 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 actuable. A command may thus be provided to the key housing 20 by actuating at least one such button. The one or more buttons may in particular comprise one or more push buttons, actuable 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 PHY 1M modality, and the key box 20 carries out in S1 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 PHY 2M 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 PHY 2M modality with the vehicle, then, once the connection is established, an exchange of “useful” frames according to the coded PHY modality or the PHY 2M modality with the vehicle. By “useful” frame, we mean a frame aiming beyond an establishment or maintenance of a connection, for example aiming to transmit to its interlocutor a command to be executed (eg, and resulting in physical actuation of vehicle hardware) 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 PHY 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 PHY 1M mode to the coded PHY mode allows sending a remote instruction according to a modality having a longer range.

[0044] In 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 above, 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 1M 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 1M 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 PHY 1M 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 started remotely 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 be activated remotely by the user, even at distances too great for the original PHY 1M. The predetermined list can exclude any vehicle unlocking instructions, in order to avoid the risk of a third party entering the vehicle when it would have been unlocked at too great a distance to prevent it.

[0047] According to one 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 1M 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 encoded 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 1M 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 PHY 1M 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 life 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 live following S2. The original PHY 1M 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 visible different 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 1M 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 PHY 1M 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] Illustrates an embodiment of such an example of the first variant of the method, where an exchange command between the key housing and the vehicle and which consists of a request to the key housing to send to the vehicle a remote instruction as described above is provided at S20 to the key housing, while no BLE connection is established between the key housing 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 1M 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 1M 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 previously described.

[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 1M modality. This sending S16 being carried out according to the original PHY 1M modality, it can be considered as 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 1M 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 an advertising signal.

[0054] The method then comprises an evaluation S30 of whether or not the key housing is close enough to the vehicle to send the remote instruction according to the original PHY 1M modality. This evaluation S30 is in this case carried out on the basis of measurements carried out by the key housing during S16. In particular, the key housing can analyze whether it is indeed receiving one or more scan requests in response to its advertising signal(s), or one or more active scan requests, which indicates the presence within range of the vehicle. If applicable, the key housing can further analyze the strength of such “scan request” signals received by the housing. This can consist of one or more RSSI measurements (acronym for “Received Signal Strength Indication”) carried out on the possible scan requests received.The method may include a comparison between the measured force and a predetermined threshold. If the force (e.g., the RSSI measurement) is below the predetermined threshold, it may be inferred that the vehicle is too far away for proper originating 1M PHY communication.

[0055] Thus, following the S30 evaluation, if it concludes that there is no vehicle detected within range, or that the vehicle is too far away even if detected, the method may include switching to coded PHY mode and sending 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 close enough to send the instruction in the original 1M PHY, then the box will actually use this mode by default in order to preserve the battery and not disturb the user.

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

[0058] A BLE connection being established, the key box and the vehicle exchange S12' periodically frames according to the original 1M PHY 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 performing S32' one or more measurements during this S12' exchange, for example in the background. Indeed, these BLE exchanges performed periodically, for example with a period of less than 1 second or less than 500 milliseconds, directly provide the appropriate information for the decision based on the evaluation S34' to send in S40 the instruction according to the original 1M PHY modality or to rather switch to the coded PHY mode.

[0059] At the precise instant of the provision S20 of the instruction to be sent, the key box can base its S34' evaluation on past measurements (i.e., carried out in S32' over a period close to 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., S33' measurements 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 measurements over a period of time greater than 500 milliseconds or 1 second, and thus to base the S34' evaluation on an evolution of the measurements, making it more robust to artifacts and occasional noise. Furthermore, using present measurements makes it possible to refine the S34' evaluation, the present measurements being 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 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 can be calculated.

[0061] The S34' evaluation can correspond to the verification that one or more metrics, or a formula based on the metrics, exceeds or not a predetermined threshold, punctually and / or on average (the threshold can be different depending on whether one is looking at a punctual or averaged metric). The S34' evaluation can thus be carried out in any way as long as it tends to carry out the switch to the coded PHY mode when the original 1M PHY connection appears degraded in view of the measurements.

[0062] In particular, the one or more measurements on which the S34' evaluation is based may include one or more measurements of the strength of a signal received by the key housing from the vehicle (e.g. RSSI measurement). In other words, the S34' evaluation is based on the strength or RSSI of the frames received from the vehicle during the original 1M PHY exchanges 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 sending in S40 in coded PHY.

[0063] Alternatively or additionally, the one or more measurements on which the S34' assessment is based may comprise one or more measurements of any or any combination of (e.g., all of) the following parameters relating to a packet error rate, taken over a predetermined period of time. 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 1M 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 1M PHY 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 retry 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 1M PHY 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 above, when such exchanges take place. The higher this rate, the more it indicates a stable original 1M PHY 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 1M 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 1M 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 respective first predetermined threshold.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 1M, but if a single metric is bad (second predetermined threshold), but below a certain criticality level (first predetermined threshold), this can be acceptable because it means an isolated indicator of a 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] Illustrates several situations where the embodiments of Figures 3 and 4 find utility. In each situation, the key housing 20 is carried by a user at a position P1, P2, P3 or P4, and the user actuates it to send a remote instruction to the vehicle 20. The figure illustrates the range 52 of communications according to the original BLE PHY 1M 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 at position P1 during the provision S20, i.e., well within the 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 carried out according to the original BLE PHY 1M 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 that has just passed, and / or the metrics indicate a packet error rate that increases over a predetermined period of time that has passed and that has just passed. 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 carried out according to the BLE PHY encoded modality (i.e., S34' very likely).

[0069] If the key box 20 is located at position P3 when S20 is provided, 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. The sending of 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 the instruction correctly.

[0070] If the key housing 20 is in position P4 when S20 is supplied, 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 receive the instruction correctly unless the user were to drive into the range 54.

[0071] It shows a gradual signal degradation, corresponding to the situation where a user moves away from the vehicle from the original 1M BLE PHY 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] Lamontre 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 1M modality, for example because a user approaches the vehicle, unlocks it and enters it. The method then comprises the positioning S110 of the key housing in a stationary manner inside the vehicle, for example because the user places the keys in a storage compartment 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 1M 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 housing's optional UWB transceiver and optional vehicle UWB anchors and / or the key housing'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 1M (for the same amount of update information). The key housing can be configured so that, if the S300 evaluation is negative, not to initiate the download, and thus wait for a new opportunity.

Claims

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 1M PHY modality;a supply (S2, S20, S200) to the key box of an exchange command between the key box and the vehicle; andfollowing 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. Method according to claim 1, wherein the command consists of a request to the key housing to send a remote instruction to the vehicle, 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 on the key housing, for example a push button. 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 1M 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 1M modality. 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 1M modality, each measurement being carried out during the first communication phase. The method of 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 (S16) one or more signals from the key box to the vehicle according to the original PHY 1M modality, the set of measurements comprising one or more measurements carried out during the sending sub-phase (S16), 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. Method according to claim 4, wherein 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 1M modality, the set of measurements comprising one or more measurements (S32') carried out during the exchange sub-phase (S12'). 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 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. Method according to 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 modality. The method of claim 8, wherein the method comprises an assessment (S300) of whether or not the key housing is inside the vehicle, optionally stationary inside the vehicle, the download (S400) following a positive result of the assessment (S300), the key housing being configured to otherwise not initiate the download. 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.

Images