BLE communication between a vehicle remote key fob and a vehicle

Abstract

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

Description

Title of the invention: BLE communication between a vehicle remote key fob and a vehicle technical field

[0001] The disclosure relates to a low-energy Bluetooth (BLE) communication method between a vehicle remote key fob and a vehicle, and a vehicle remote key fob configured for such a communication method. Technical background

[0002] Vehicle remote key fobs, often called "key fobs" or "key identifiers," are particularly energy-intensive, notably due to their BLE communication with a vehicle. Given the desired compactness and light weight of these fobs, the integrated batteries generally have limited capacity. In order to maintain a relatively long battery life, for example, at least two years, BLE communication between the key fob and the vehicle is usually carried out using the original PHY IM modality of the BLE protocol. However, the communication characteristics using this modality are limited, particularly with regard to communication range and / or data rate.

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

[0004] A method for communication between a vehicle remote key fob and a vehicle is proposed. The key fob is configured to perform Bluetooth Low Energy (BLE) communication with the vehicle. The method includes a first communication phase between the key fob and the vehicle. This first communication phase is carried out using the original PHY IM modality. The method further includes providing the key fob with a command to exchange information between the key fob and the vehicle. Following this command, the method also includes a second communication phase between the key fob and the vehicle. This second communication phase is carried out using either a coded PHY modality or a PHY 2M modality.

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

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

[0007] Optionally, for this first variant, the evaluation can 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 performed during the first communication phase.

[0008] According to one embodiment, the command can be initiated before the end of the first communication phase and while no BLE connection is established between the key fob and the vehicle. Following the command, the first communication phase includes a sub-phase of sending one or more signals from the key fob to the vehicle according to the original PHY IM modality. The measurement set includes one or more measurements taken during the sending sub-phase. The evaluation provides a negative result following an indication, by the measurement set, of the absence of a signal received by the key fob in response to the sending of one or more signals from the key fob, or of a signal strength lower than a predetermined threshold when the signal received by the key fob from the vehicle is sent after the sending of one or more signals from the key fob.

[0009] According to another embodiment, the command can be issued after the start of the first communication phase and while a BLE connection is established between the key fob and the vehicle. The first communication phase includes, prior to the command, a sub-phase of exchanging one or more frames between the key fob and the vehicle according to the original PHY IM modality. The measurement set includes one or more measurements performed during the exchange sub-phase.

[0010] In an example of this other embodiment, the one or more measurements taken during the exchange subphase include one or more measurements of the strength of a signal received by the key fob 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 retries, 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 fob to download an update from the vehicle. The second communication phase includes a download of the update by the key fob from the vehicle according to the PHY 2M modality.

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

[0013] A vehicle remote control key fob configured to perform BLE communications with a vehicle is also proposed. The key fob is configured to communicate with the vehicle according to the proposed method. The key fob can 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 proposed for each respective variant, and / or according to one or both of the embodiments proposed for an option of the first variant.

[0014] A computer program is also proposed, comprising instruction code configured, when executed by a vehicle remote key fob, to perform the proposed method with a vehicle. The program can be installed on the memory of a vehicle remote key fob already configured to perform BLE communications with a vehicle, and the program can thus add a configuration to the key fob enabling it to communicate with the vehicle according to the proposed method. The computer program can include 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 proposed for each respective variant, and / or according to one or both of the embodiments proposed for an option of the first variant.

[0015] A computer program is also proposed comprising instruction code configured, when executed by a vehicle, to perform the method according to the proposed method with a vehicle remote key fob. The program can be installed on the memory of a vehicle already configured to perform BLE communications with a vehicle remote key fob, and the program can thus add a configuration to the vehicle enabling it to communicate with the vehicle remote key fob according to the proposed method. The computer program can include 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 proposed 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] Figure 1 shows the proposed method of communication between a key fob box vehicle order and a vehicle, where the order of steps as represented on the diagram is not necessarily representative of the actual chronology.

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

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

[0020] Figure 4 shows another embodiment of an example of the first variant of the process.

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

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

[0023] Figure 7 shows an example of the second variant of the process. Detailed description

[0024] Figure 1 shows a method for communication between a vehicle and a vehicle remote key fob (also known as an "identifier" or "keyfob," a commonly used English term). The key fob is configured to perform BLE communications with the vehicle. The method includes a first communication phase (SI) between the key fob and the vehicle. This first communication phase (SI) is carried out using the original PHY IM modality. The method further includes providing the key fob with a command (S2) to exchange information between the key fob and the vehicle. Following this command, the method also includes a second communication phase (S4) between the key fob and the vehicle, this second communication phase being carried out using either a coded PHY modality or a PHY 2M modality.

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

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

[0027] The method's ability to provide a given exchange command between the key fob and the vehicle in S2, and subsequently for the key fob to initiate a second communication phase S4 with the vehicle using either a coded PHY or a PHY 2M modality, overcomes the limitations of the original PHY IM modality. In particular, the original PHY IM modality has a limited range. The coded PHY modality increases this range, thus enabling, for example, sending a command to the vehicle at a distance where this would be impossible or difficult using the original PHY IM modality. Furthermore, the original PHY IM modality has a limited data rate. The PHY 2M modality increases the data rate, for example, when faster exchange of a large amount of data is required.The dynamic switching from the original PHY IM modality to the coded PHY modality or the PHY 2M modality thus allows for optimization of the exchanges controlled at the key fob, by optimally exploiting different possible BLE communication modalities.

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

[0029] The vehicle 30 can be a car, a motorcycle, a truck, or more generally any land vehicle. The vehicle includes a BLE transceiver, configured to perform BLE exchanges with the key fob 20. The vehicle 30 and the key fob 20 may have been previously paired (according to the BLE protocol) to enable these exchanges.

[0030] The vehicle remote control key fob 20, or "identifier," may include a protective housing 22 enclosing components of the key fob 20. The protective housing 22 may be made of plastic, metal, and / or rubberized plastic. The key fob 20 may include 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 trademark. The logo disrupts BLE communications, and thus the logo may contribute to the failure of certain BLE communications carried out according to the original PHY IM modality when they are performed at too great a distance between the key fob 20 and the vehicle 30.The key housing 20 may include inside the protective housing 22 a metal insert 24, which allows the vehicle 30 to be opened and / or started manually, by inserting and manipulating the insert into a respective lock of the vehicle 30. The metal insert 24 also disrupts BLE communications.

[0031] The key housing 20 includes at least one BLE transceiver 26, configured To perform BLE exchanges with vehicle 30, the transceiver 26 may comprise or consist of an electronic microchip, including a microprocessor and an antenna adapted for BLE communication. The microprocessor may have in its memory a computer program enabling BLE communications and performing various specific functions, such as initiating the second communication phase S4.

[0032] In particular, the transceiver 26 can 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 housing 20 can be such that the same transceiver 26 performs both exchanges occurring in SI and exchanges occurring in S4. This offers a more compact key housing 20 and reduces the number of components. Alternatively, the function of the transceiver 26 can be limited to exchanges according to the original PHY IM modality, and the key housing 20 can include at least one additional transceiver for exchanges according to the coded PHY modality and / or the PHY 2M modality.

[0033] Optionally, the key fob 20 can be configured to communicate in addition to the original PHY IM mode, and also to communicate in both the coded PHY and PHY 2M modes. Thus, the method can be repeated, with at least one repetition where communication in S4 is in the coded PHY mode, and one repetition where communication in S4 is in the PHY 2M mode. The method can include selecting the mode for S4 based on the nature of the command provided in S2. The key fob 20 is therefore configured to dynamically switch between different PHY modes depending on the situation, with the original PHY IM mode serving as the pivot. Examples of the method where communication in S4 is in the coded PHY mode, and examples of the method where communication in S4 is in the PHY 2M mode, are subsequently provided.The procedure can be repeated to achieve any combination of these examples, for example, each of these examples. Accordingly, the key fob 20 can be configured to communicate with the vehicle 30 according to any one of these examples depending on the situation, for example, each of these examples depending on the situation.

[0034] The key housing 20 also includes a battery 28, which provides 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 can be a button cell and / or a 3V battery or a battery with a voltage between IV and 10V.

[0035] The key housing 20 may optionally include a UWB transceiver (acronym for "Ultra Wide Band"). Large"), configured to perform UWB exchanges with vehicle 30. The UWB transceiver may comprise or consist of an electronic microchip, including a microprocessor and an antenna adapted for UWB communication. The microprocessor may have in memory a computer program enabling UWB communications and performing various specific functions, such as allowing vehicle 30 to locate key fob 20. Vehicle 30 may optionally include UWB anchors, each with a transceiver adapted to calculate the distance to key fob 20 via UWB exchanges.

[0036] The key fob 20 may also optionally include a motion sensor, configured to detect movement of the key fob 20. Such detections allow for the management of BLE communications between the key fob 20 and the vehicle 30. For example, a stationary key fob 20 can stop or reduce the frequency of any BLE signal transmission, at least in certain situations. In this case, movement of the initially stationary key fob 20, detected by the motion sensor, can initiate or accelerate the transmission of BLE signals, for example, in an attempt to re-establish a BLE connection with the vehicle 30.

[0037] The "Bluetooth Low Energy" (BLE) protocol is the communication standard commonly used for communications involving data exchange between a vehicle remote control key fob and a vehicle, for example, so that the key fob can transmit remote commands to the vehicle, and / or so that the vehicle can transmit update data to the key fob. The standard allows for the implementation of different communication modalities, known as "PHY" (Physical Layer), at the protocol's physical layer.

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

[0039] Therefore, the original PHY IM modality is the preferred modality for implementing BLE communication between the vehicle key fob and the vehicle is preferred because it best preserves battery life while maintaining a range of several tens of meters for controlling the vehicle, which is generally satisfactory. However, there may be specific situations where the coded PHY mode, which allows for a longer range, can be useful, for example, for certain remote commands that need to be performed at a distance exceeding 100 meters or even 250 meters. Alternatively, there may also be specific situations where the PHY 2M mode, which allows for a higher data rate, can be useful, for example, for certain exchanges of large amounts of data that need to be carried out as quickly as possible, particularly during a software update of the key fob.

[0040] With reference to Figures 1 and 2, such situations can arise as a result of a specific communication command between the key fob 20 and the vehicle 30 provided to the key fob 20, particularly in step S2. This refers to any action performed on the key fob 20 so that the key fob 20 executes a BLE communication exchange with the vehicle 30. The command can be physical, thus involving a physical operation on the key fob 20. In particular, the key fob 20 may include one or more buttons, each of which can be actuated. A command can thus be provided to the key fob 20 by actuating at least one such button. The one or more buttons may, in particular, include one or more pushbuttons, actuated by pressing.The key fob 20 can be configured to receive a command via S2 by pressing a single button, for example, a single push button, and / or to receive a command via S2 by pressing multiple buttons, for example, each button pressed simultaneously or according to a predetermined sequence. Alternatively or additionally, the command can be provided to the key fob 20 via a signal via S2. For example, the key fob 20 can receive a request for an update signal from the vehicle, corresponding to a command to initiate an update.

[0041] Thus, during the process, the key fob 20 is initially in a first BLE communication mode according to the original PHY IM modality, and the key fob 20 performs a communication in SI with the vehicle 30 according to this first mode. Following S2, and possibly the evaluation of certain conditions, the key fob 20 switches to a second communication mode according to the PHY coded modality or the PHY 2M modality, and it thus sends all signals in S4 according to this second mode. The S4 step may notably include establishing a BLE connection according to the PHY coded modality or the PHY 2M modality with the vehicle, then, once the connection is established, exchanging "useful" frames according to the PHY coded modality or the PHY 2M modality with the vehicle. By "useful" frame, we mean a frame intended to go beyond establishing a connection. or maintaining a connection, for example aimed at transmitting to its interlocutor a command to be executed (e.g., and resulting in a physical actuation of a piece of equipment in the vehicle) or information to be recorded in non-volatile memory.

[0042] Examples of the process according to the first variant (and corresponding configuration of the key housing 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 fob 20 to send a remote instruction to the vehicle 30. The second communication phase S4 may then include the transmission of said instruction from the key fob 20 to the vehicle 30, this transmission being carried out in the coded PHY mode. Thus, the ability to switch from the original IM PHY mode to the coded PHY mode allows the transmission of a remote instruction in a mode with a longer range.

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

[0045] According to the method, the instruction is sent to S4 using the coded PHY mode. To achieve this, the key fob S20 can switch from its original default PHY IM mode to a coded PHY mode that it supports. This allows for better vehicle contact and enables the vehicle to execute the instruction, even if the key fob 20 is located at a considerable distance from the vehicle. For example, the user and / or the fob 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 using the original default PHY IM mode.

[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 switching functionality from the original IM PHY mode to the coded PHY mode with a longer range. The predetermined list may include a lock instruction, allowing the vehicle to be locked remotely; a remote start instruction, allowing the engine to be started remotely from outside the vehicle in order to preheat it; a preconditioning instruction, allowing the vehicle's air conditioning or heating to be started from outside the vehicle; and / or a hazard warning instruction, allowing the vehicle's horn to be sounded remotely, for example, in the event of a panic or danger situation.Such functions are useful because they can be activated remotely by the user, even at distances. Too important for the original PHY IM. The predetermined list may exclude any vehicle unlocking instructions, in order to avoid the risk of a third party entering the vehicle when it has been unlocked at too great a distance to prevent it.

[0047] By way of example, the method may include an evaluation of whether or not the key fob 20 is sufficiently close to the vehicle to send the remote instruction according to the original PHY IM modality. This evaluation may be performed by a microprocessor of the key fob 20, for example, the microprocessor of the transceiver 26. The remainder of the method may be conditional upon this evaluation. In particular, sending the remote instruction from the key fob 20 to the vehicle 30 according to the coded PHY modality follows a negative result of the evaluation. And the key fob 20 is otherwise configured to send the remote instruction from the key fob 20 to the vehicle 30 according to the original PHY IM modality.In other words, the key box 20 is configured to, upon receiving the S2 command: 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 IM modality, otherwise send the instruction according to the coded PHY modality.

[0048] Thus, the increased power consumption of the battery 28 caused by switching to the coded PHY mode is limited to only those cases where it is necessary, thereby optimizing the battery life. Furthermore, this allows for a uniform response from the vehicle 30 to a remote instruction sent by the key fob 20, whether the instructions belong to the predetermined list or not, provided the key fob 20 is sufficiently close to the vehicle, and the user can therefore potentially see the vehicle's live response following S2. The original IM PHY mode and the coded PHY mode have significantly different signal characteristics, so the vehicle's responsiveness differs depending on whether the same instruction is sent from the same key fob, located in the same position, or whether the instruction is sent in one mode or the other.Using the coded PHY modality only when necessary, i.e., at a sufficiently long distance, avoids visible differences in vehicle behavior depending on the instruction given, in terms of reaction time, which is undesirable from an ergonomic point of view for the user.

[0049] 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 performed by the key box 20 during the first communication phase S2. Thus, during the first communication phase S2, the key fob 20 measures whether the connection exists and / or is strong enough to maintain the original PHY IM mode. If not, the key fob 20 switches to the coded PHY mode to increase the chances of successfully communicating with the vehicle during the second communication phase S4.

[0050] Figure 3 illustrates one embodiment of such an example of the first variant of the method, where an exchange command between the key box and the vehicle, consisting of a request to the key box to send 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 includes a first sub-phase S12 of the first communication phase between the key fob and the vehicle. "Sub-phase" refers to a portion of the first communication phase. This sub-phase S12 is implemented according to the original PHY IM modality. At some point and for some reason, a loss S14 of the BLE connection occurs. This loss S14 of connection may occur, for example, because the user has moved away from their vehicle beyond the BLE range of the original PHY IM modality for a period exceeding a predetermined duration, and / or because the key fob has remained stationary outside the vehicle (which can be detected based on measurements from the optional motion sensor) for a period exceeding a predetermined duration, optionally when the last exchange command provided to the fob was to send the vehicle a vehicle lock instruction.

[0052] Subsequently, the method includes providing S20 to the key box with an exchange command between the key box and the vehicle, consisting of a request to the key box to send the vehicle a remote instruction, as described previously.

[0053] Following this command provided in S20, the method includes an S16 transmission of one or more signals from the key fob to the vehicle according to the original PHY IM modality. Since this S16 transmission is carried out according to the original PHY IM modality, it can be considered as a second sub-phase of the first communication phase. In the absence at that moment of an established BLE connection between the key fob and the vehicle, this S16 transmission may include 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 may respond to such an advertising signal with a scan request. Alternatively, the vehicle may have actively sent a scan request, and the S16 transmission may consist of responding to it with a signal of advertisement.

[0054] The method then includes an S30 evaluation of whether or not the key fob is sufficiently close to the vehicle to send the remote instruction according to the original PHY IM modality. This S30 evaluation is based on measurements taken by the key fob during S16. In particular, the key fob can analyze whether it is receiving one or more scan requests in response to its advertising signal(s), or one or more active scan requests, which indicates the vehicle's presence within range. If so, the key fob can further analyze the strength of such "scan request" signals received by the fob. This can consist of one or more RSSI (Received Signal Strength Indication) measurements taken on any received scan requests.The process 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 can be inferred that the vehicle is too far away for proper PHY IM communication.

[0055] Thus, following the S30 evaluation, if it concludes that no vehicle is 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 from the key fob to the vehicle in coded PHY mode. The probability that the remote instruction will be successfully received by the vehicle is thus increased.

[0056] If, on the other hand, the S30 evaluation concludes that the vehicle is close enough for sending the instruction in PHY IM of origin, then the box will indeed use this mode by default in order to preserve the battery and not to disturb the user.

[0057] Figure 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, consisting of a request to the key box to send 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] Once a BLE connection is established, the key fob and the vehicle periodically exchange frames S12' according to the original PHY IM modality, in order to maintain the connection, as generally known in the BLE protocol, for example every 50 milliseconds or every 100 milliseconds, depending on the BLE protocol option selected. The method may include performing one or more measurements S32' during this exchange S12', for example as a background task. Indeed, these periodically performed BLE exchanges, 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 the instruction in S40 according to the original PHY IM modality or to switch to the coded PHY mode.

[0059] At the precise moment S20 of the instruction to be sent, the key fob can base its evaluation S34' on past measurements (i.e., measurements taken in S32' over a recent period, for example, over a duration that began less than 5 seconds or 2 seconds before the detection of the S20 supply) and / or on present measurements (i.e., measurements S33' in progress or to be taken in the very near future, ending within 1 second or 500 milliseconds immediately following the detection of the S20 supply). Using past measurements allows for the use of more measurements, for example, all measurements over a period of time greater than 500 milliseconds or 1 second, and thus bases the evaluation S34' on an evolution of the measurements, making it more robust to artifacts and isolated noise. Furthermore, using present measurements allows for a more refined evaluation S34', as present measurements are the most representative of what is to be anticipated.

[0060] The measurements may relate to one or more metrics that together indicate the strength of a received signal and / or the 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 out over time. A metric may thus have a point value, corresponding to the measurement(s) taken at a given instant to calculate the metric, or an average value, because if several measurements spaced out over 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 verifying whether one or more metrics, or a formula based on metrics, exceeds a predetermined threshold, either at a specific point in time and / or on average (the threshold may differ depending on whether a point or averaged metric is being considered). The S34' evaluation can thus be performed in any way as long as it tends to switch to the coded PHY mode when the original PHY IM connection appears degraded based on 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 fob 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 IM PHY exchanges during the existing connection, for example, the exchanges performed periodically to maintain the existing connection. A decrease in the strength or RSSI indicates a degradation of the connection, and thus favors sending an S40 PHY-encoded signal.

[0063] Alternatively or additionally, the one or more measures on which The S34' evaluation may include one or more measurements of one or any combination of the following (e.g., all) parameters related to a packet error rate, taken over a predetermined period. In particular, the one or more measurements may include RSSI, which allows for a simple determination of whether the connection is good or bad, and the S34' evaluation can be advantageously refined by additional measurements available through the BLE exchange according to the current PHY IM modality.

[0064] With reference to the Bluetooth protocol, the method can measure, in the first category of parameters relating to a packet error rate, the number of packets (correctly) received and / or the number of events or frames (correctly) initiated. The higher the value of this or these parameters, particularly compared to the parameters in the second category, the more this indicates a stable PHY IM connection from the origin, and therefore one that can be maintained. The method can also measure, in the second category of parameters relating to a packet error rate, the number of failed redundancy checks, the number of retransmission attempts, and / or the number of missed connection events. The lower the value of this or these parameters, particularly compared to the parameters in the first category, the more this indicates a stable PHY IM connection from the origin, and therefore one that can be maintained.The process can also measure, as a third category of parameters relating to packet error rate, the transmission rate of "useful" data or frames, as defined previously, when such exchanges take place. The higher this rate, the more it indicates a stable PHY IM connection of origin, 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 if the stability falls below a predetermined threshold, the connection is evaluated in S34' as poor, and the remote instruction is sent in S40 in PHY-encoded mode. For example, the method can continuously and in the background during the exchange of originating 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 process can continuously average these measurements over a sliding time window that includes frame exchanges, and the S34' evaluation can conclude that the distance is too great to send the remote instruction via the originating 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 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 corresponding 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 may be acceptable as signifying 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] Figure 5 illustrates several situations where the embodiments of Figures 3 and 4 are useful. In each situation, the key fob 20 is carried by a user in a position P1, P2, P3, or P4, and the user activates it 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 fob 20 is in position PI during the S20 provisioning, i.e., well within range 52, then the RSSI signal received by the key fob 20 from the vehicle is high. Furthermore, a BLE connection is likely established, and the metrics also indicate a low packet error rate. Therefore, the remote instruction is sent 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 fob 20 is in position P2 during the S20 provisioning, i.e., at the limit of range 52, then the RSSI signal received by the key fob 20 from the vehicle has gradually decreased over a predetermined past and just elapsed time period, and / or the metrics indicate a packet error rate that is increasing over a predetermined past and just elapsed time period. Therefore, the remote instruction can be sent using the coded BLE PHY method, depending on the situation (i.e., S34' is possible). If the user was actually approaching vehicle 30 when they reached P2 and activated the key fob 20, and / or remained in P2 for some time, then the received RSSI signal was previously weak and the packet error rate high, so that in this case, the remote instruction transmission is most likely carried out using the BLE PHY-encoded modality (i.e., S34' very likely).

[0069] If the key fob 20 is in position P3 during the S20 provisioning, i.e., well outside the range 52 but well within the 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 remote instruction is most likely sent in the BLE PHY-encoded mode (i.e., S30 is very likely), and it is probable that the vehicle receives it correctly. instruction.

[0070] If the key fob 20 is in position P4 during the S20 supply, i.e., well outside the range 54, then no signal is received from the car. Transmission can still occur via coded BLE PHY, but it is unlikely that the vehicle will correctly receive the instruction unless the user moves within 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 process according to the second variant (and corresponding configuration of the key housing 20) where the second communication phase S4 is carried out according to the modality PHY 2M are now described.

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

[0074] Figure 7 shows an embodiment of this second variant. In this embodiment, the method comprises a first communication phase S100 between the key fob 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 SI10 of the key fob in a stationary position inside the vehicle, for example, because the user places the keys in a storage compartment inside the vehicle. The method then comprises providing the key fob, via a signal sent by the vehicle according to the original PHY IM modality, with a request to download a software update. The method comprises an evaluation S300 by the key fob of whether or not the key fob is stationary and inside the vehicle.This can be achieved using the key fob's optional UWB transceiver and optional vehicle UWB anchors and / or the key fob's optional motion sensor. Following a positive S300 assessment, the S400 download can be initiated via PHY 2M, resulting in a faster download than the original PHY IM (for the same amount of update information). The key fob can be configured to prevent the download from initiating if the S300 assessment is negative, allowing the device to wait for a future opportunity.

Claims

Demands

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

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

3. A method according to claim 2, wherein the method comprises an evaluation (S30, S32'-S34') of whether or not the key fob is close enough to the vehicle to send the remote instruction according to the original PHY IM modality, sending (S20) the remote instruction from the key fob to the vehicle according to the coded PHY modality following a negative result of the evaluation, the key fob being configured to otherwise send the remote instruction from the key fob 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 performed during the first phase of communication.

5. A 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 fob 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 fob to the vehicle according to the original PHY IM modality, the measurement set comprising one or more measurements taken during the sending sub-phase (S16), the evaluation (S30) providing a negative result following an indication by the measurement set of an absence of a signal received by the key fob in response to the sending of one or more signals from the key fob, or of a lower strength of a signal received by the key fob from the vehicle in response to the sending of one or more signals from the key fob compared to a predetermined threshold.

6. 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 IM modality, the set of measures comprising one or more measures (S32') carried out during the sub-phase of exchange (S12').

7. A method according to claim 6, wherein the one or more measurements taken during the exchange subphase include one or more measurements of the strength of a signal received by the key fob 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 retries, • a number of missed connection events, and / or • a data transmission rate.

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

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

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