Hands-free systems for vehicles

Abstract

The invention relates to a hands-free system for vehicles, comprising: a) an identifier comprising a first BLE module configured to transmit events comprising primary frames, b) a vehicle device comprising a third BLE module configured to receive the events, characterized in that: c) a primary frame comprises a location indication indicating a location of a first auxiliary frame comprising a synchronization index for synchronizing with second auxiliary synchronization frames, d) the first BLE module is furthermore configured to: - transmit the first auxiliary frame and the second auxiliary synchronization frames so that the vehicle device synchronizes with the second auxiliary synchronization frames, - after the synchronization, receive a BLE connection request from the vehicle device following a distance estimation indicating whether the hands-free identifier is within a BLE range of the vehicle, e) the third BLE module is furthermore configured to: - search for the first auxiliary frame based on the location indication, - decode the first auxiliary frame in order to extract therefrom the synchronization index, - synchronize with the second auxiliary synchronization frames, - after the synchronization, carry out one or more RSSI measurements, perform a distance estimation based on the one or more RSSI measurements, and transmit the BLE connection request to make a BLE connection with the identifier following the distance estimation indicating whether the identifier is within a BLE range of the vehicle.

Description

Hands-free vehicle systems

[0001] The present invention relates to a hands-free vehicle access and automatic start system. It also relates to a method for locating a hands-free vehicle access and automatic start identifier relative to said vehicle. It also relates to a hands-free vehicle access and automatic start identifier. It also relates to a vehicle device for automatic vehicle access and starting. It also relates to a first communication method implemented by said hands-free vehicle access and automatic start identifier. It also relates to a vehicle device for automatic access and starting and a second communication method implemented by said vehicle device.

[0002] It finds a particular but not limited application in the field of motor vehicles.

[0003] In the field of motor vehicles, a hands-free access and automatic starting system for a vehicle comprises, in a manner known to those skilled in the art: a) a hands-free identifier (Id) comprising a first BlueTooth Low Energy module TM(referenced as BLE) configured to transmit events according to a BLE communication protocol when said hands-free identifier is in an announcement mode, an event comprising a plurality of frames transmitted on primary channels, and to receive a BLE connection request from said vehicle following a distance estimation indicating whether said hands-free identifier is within BLE range relative to said vehicle,b) a vehicle device comprising a third BLE communication module of said vehicle configured to receive said events transmitted by said hands-free identifier when said vehicle is in a scanning mode, to perform said distance estimation from one or more RSSI measurements, and to transmit said BLE connection request to perform a BLE connection with said hands-free identifier following said distance estimation.

[0004] A disadvantage of this prior art is that the hands-free identifier includes a battery whose autonomy must be approximately 2 years according to the requirements of motor vehicle manufacturers. In order to have low energy consumption and thus preserve the battery of the hands-free identifier, the hands-free identifier emits an event over a high time interval (of the order of 3 to 4 seconds). On the vehicle side, the vehicle must therefore listen to a primary channel over a high scanning window to be able to retrieve an event. The problem is that this results in significant energy consumption on the vehicle side.

[0005] In this context, the present invention aims to propose a hands-free system which proposes to solve the mentioned drawback.

[0006] For this purpose, the invention proposes a hands-free access and automatic start system for a vehicle, said hands-free system comprising:a) a hands-free identifier comprising a first BLE communication module configured to transmit events according to a BLE communication protocol when said hands-free identifier is in an announcement mode, an event comprising a plurality of primary frames transmitted on primary channels,b) a vehicle device comprising a third BLE communication module configured to scan said events transmitted by said hands-free identifier when said vehicle is in a scanning mode,Characterized in that:c) a primary frame comprises a location indication indicating the location of a first auxiliary frame, said first auxiliary frame comprising a synchronization index with second auxiliary synchronization frames,and in that:d) said first BLE communication module is further configured to:- transmit said first auxiliary frame and said second auxiliary synchronization frames on secondary channels so that the vehicle device synchronizes said second auxiliary synchronization frames, and- receive after said synchronization a BLE connection request from said vehicle device following a distance estimation indicating whether said hands-free identifier is within BLE range relative to said vehicle, and in that:e) said third BLE communication module is further configured to:- search for said first auxiliary frame in a secondary channel from said location indication,- decode said first auxiliary frame to extract the synchronization index therefrom, and- according to said synchronization index synchronize with the second auxiliary synchronization frames,- after said synchronization, performing one or a plurality of RSSI measurements and performing a distance estimation from said plurality of RSSI measurements,- after said distance estimation, issuing said BLE connection request to perform a BLE connection with said hands-free identifier following said distance estimation indicating whether said hands-free identifier is within BLE range relative to said vehicle.,

[0007] Thus, as we will see in detail below, the synchronization between the transmission of events by the hands-free identifier and the scanning by the vehicle makes it possible to reduce energy consumption on the vehicle side since the latter will listen to a primary channel only when necessary.

[0008] According to non-limiting embodiments, said hands-free system may further comprise one or more additional characteristics taken alone or in all technically possible combinations, among the following.

[0009] According to a non-limiting embodiment, said primary frames are transmitted in a first time interval.

[0010] According to a non-limiting embodiment, a first time interval is spaced from another first time interval by a time period of random value.

[0011] According to a non-limiting embodiment, said synchronization index is indicative of a second time interval separating the transmission of two second consecutive auxiliary synchronization frames.

[0012] According to a non-limiting embodiment, said second time interval is periodic.

[0013] According to a non-limiting embodiment, said synchronization is a synchronization of the scanning mode with said second auxiliary synchronization frames.

[0014] According to a non-limiting embodiment, a) said hands-free identifier further comprises a second UWB communication module configured to, after the BLE connection, receive UWB signals from said vehicle device for a UWB distance measurement relative to said vehicle, and transmit in return UWB return signals for said UWB distance measurement, and b) said vehicle device further comprises a fourth UWB communication module configured to, after the BLE connection, transmit said UWB signals, to receive said UWB return signals, and to perform said UWB distance measurement from said UWB signals and said UWB return signals.

[0015] According to a non-limiting embodiment, the location indication is located in a header of a frame.

[0016] Further provided is a method for locating a hands-free vehicle access and auto-start identifier relative to a vehicle, said hands-free identifier comprising a first BLE communication module and said vehicle comprising a vehicle device, the latter comprising a third BLE communication module, characterized in that said locating method comprises:- a transmission by said first BLE communication module of events according to a BLE communication protocol when said hands-free identifier is in an announcement mode, and a reception by said third BLE communication module of said events when said vehicle is in a scanning mode, an event comprising a plurality of primary frames transmitted on primary channels, a primary frame comprising a location indication indicating the location of a first auxiliary frame,said first auxiliary frame comprising a synchronization index with second auxiliary synchronization frames,- a transmission by said first BLE communication module of said first auxiliary frame and said second auxiliary synchronization frames on secondary channels so that said vehicle device synchronizes said second auxiliary synchronization frames,- a scan by said third BLE communication module of said events to extract said location indication therefrom,- a search by said third BLE communication module of said first auxiliary frame in a secondary channel from said location indication,- a decoding by said third BLE communication module of said first auxiliary frame to extract said synchronization index therefrom, and- according to said synchronization index,a synchronization by said third BLE communication module with said second auxiliary synchronization frames,- after said synchronization, a performance by said third BLE communication module of one or more RSSI measurements and a distance estimation by said third BLE communication module from said one or more RSSI measurements,- after said distance estimation, a transmission by said third BLE communication module of a BLE connection request following said distance estimation indicating whether said hands-free identifier is within BLE range relative to said vehicle, and a reception by said first BLE communication module of said BLE connection request,- a BLE connection between said hands-free identifier and said vehicle device.,

[0017] According to a non-limiting embodiment, the localization method further comprises: - after said BLE connection, a transmission by said fourth UWB communication module of UWB signals for a UWB distance measurement of said hands-free identifier relative to said vehicle, and a reception by said second UWB communication module of said UWB signals, - a return transmission of UWB return signals for said UWB distance measurement, - a distance measurement by said fourth UWB communication module of said hands-free identifier from said UWB signals and said UWB return signals.

[0018] There is further provided a hands-free access and auto-start identifier for a vehicle comprising a first BLE communication module configured to transmit events according to a BLE communication protocol when said hands-free identifier is in an announcement mode, an event comprising a plurality of primary frames transmitted on primary channels,Characterized in that:a) a primary frame comprises a location indication indicating the location of a first auxiliary frame, said first auxiliary frame comprising a synchronization index with second auxiliary synchronization frames,and in that:b) said first BLE communication module is further configured to:- transmit said first auxiliary frame and said second auxiliary synchronization frames on secondary channels such that said vehicle device synchronizes with said second auxiliary synchronization frames,and- receiving after said synchronization a BLE connection request from said vehicle device following a distance estimation indicating whether said hands-free identifier is within BLE range relative to said vehicle.,

[0019] According to a non-limiting embodiment, said hands-free identifier further comprises a second UWB communication module configured to, after the BLE connection:- receive UWB signals from said vehicle for a UWB distance measurement relative to said vehicle,- transmit in return UWB return signals for said UWB distance measurement.

[0020] Further provided is a first method of communicating a hands-free vehicle access and auto-start identifier with a vehicle device for locating it relative to said vehicle, said hands-free identifier comprising a first BLE communication module, characterized in that said first communication method comprises:- a transmission by said first BLE communication module of events according to a BLE communication protocol when said hands-free identifier is in an announcement mode, an event comprising a plurality of frames transmitted on primary channels, a frame comprising a location indication indicating where a first auxiliary frame is located, said first auxiliary frame comprising a synchronization index with second auxiliary synchronization frames,- a transmission by said first BLE communication module of a first auxiliary frame and said second auxiliary synchronization frames on secondary channels so that a vehicle device synchronizes said second auxiliary synchronization frames,- after said synchronization, a reception by said first BLE communication module of a BLE connection request transmitted by said vehicle device following a distance estimation indicating whether said hands-free identifier is within BLE range relative to said vehicle,- a BLE connection with said vehicle device following the reception of said BLE connection request.,

[0021] According to a non-limiting embodiment, the first communication method further comprises after said BLE connection: - reception by a second UWB communication module of said hands-free identifier of UWB signals emitted by said vehicle device for a UWB distance measurement of said hands-free identifier relative to said vehicle, - a return transmission of UWB return signals for said UWB distance measurement.

[0022] Further provided is a vehicle device for automatic vehicle access and starting, said device comprising a third BLE communication module configured to scan events emitted by said hands-free identifier according to a BLE communication protocol when said vehicle is in a scanning mode, an event comprising a plurality of primary frames emitted on primary channels,Characterized in that said third BLE communication module is further configured to:- search for a first auxiliary frame in a secondary channel from a location indication included in a primary frame,- decode said first auxiliary frame to extract a synchronization index therefrom, and- depending on the synchronization index, synchronize with second synchronization auxiliary frames emitted by said hands-free identifier on secondary channels,- after said synchronization,performing one or a plurality of RSSI measurements and performing a distance estimation from said plurality of RSSI measurements,- after said distance estimation, issuing said BLE connection request to perform a BLE connection with said hands-free identifier following said distance estimation indicating whether said hands-free identifier (Id) is within BLE range relative to said vehicle,- performing a BLE connection with said hands-free identifier.,

[0023] According to a non-limiting embodiment, said synchronization is a synchronization of the scanning mode with said second auxiliary synchronization frames.

[0024] According to a non-limiting embodiment, said vehicle device further comprises a fourth UWB communication module configured to:- transmit UWB signals for a UWB distance measurement of said hands-free identifier relative to said vehicle,- receive in return UWB return signals transmitted by a second UWB communication module of said hands-free identifier, and- carry out said UWB distance measurement.

[0025] There is further provided a second method of communicating a vehicle device with a hands-free vehicle access and auto-start identifier for locating said hands-free identifier relative to said vehicle, said vehicle device comprising a third BLE communication module, characterized in that said second method of communicating comprises:- reception by said third BLE communication module of events transmitted by said hands-free identifier according to a BLE communication protocol when said vehicle is in a scanning mode, an event comprising a plurality of primary frames transmitted on primary channels, a primary frame comprising a location indication indicating where a first auxiliary frame is located, said first auxiliary frame comprising a synchronization index with second auxiliary synchronization frames,- a scan by said third BLE communication module of said events to extract said location indication therefrom,- a search by said third BLE communication module of said first auxiliary frame in a secondary channel from said location indication,- a decoding by said third BLE communication module of said first auxiliary frame to extract said synchronization index therefrom, and- depending on said synchronization index, a synchronization by said third BLE communication module with the second auxiliary synchronization frames,- after said synchronization, a performance by said third BLE communication module of one or a plurality of RSSI measurements and a distance estimation by said third BLE communication module from the one or more plurality of RSSI measurements,- after said distance estimation,a transmission by said third BLE communication module of a BLE connection request following said distance estimation indicating whether said hands-free identifier is within BLE range relative to said vehicle,- a BLE connection with said hands-free identifier.,

[0026] According to a non-limiting embodiment, the second communication method further comprises:- a transmission by a fourth UWB communication module of said vehicle device of UWB signals for a UWB distance measurement of said hands-free identifier relative to said vehicle,- a reception of UWB return signals transmitted by a second UWB communication module of said hands-free identifier,- a UWB distance measurement by said fourth UWB communication module of said hands-free identifier relative to said vehicle from said UWB signals and said UWB return signals.

[0027] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures:

[0028] is a schematic figure of a hands-free access and automatic start system for a vehicle, according to a non-limiting embodiment of the invention, said hands-free system comprising a hands-free identifier comprising a first BLE communication module and a second UWB communication module, and a vehicle device comprising a third BLE communication module and a fourth UWB communication module,

[0029] is a diagram illustrating a synchronization of a scanning mode of the vehicle device with a transmission of frames by said hands-free identifier of the,

[0030] is a diagram of a non-limiting embodiment of a method for locating a hands-free vehicle access and auto-start identifier relative to said vehicle, said locating method being implemented by said hands-free system of the,

[0031] is a diagram of a non-limiting embodiment of a first method of communicating a hands-free vehicle access and auto-start identifier with a vehicle device for its location relative to said vehicle, said first communication method being implemented by said hands-free identifier of the,

[0032] is a diagram of a non-limiting embodiment of a second method of communicating a vehicle device with a hands-free vehicle access and auto-start identifier for locating said hands-free identifier relative to said vehicle, said second method of communication being implemented by said vehicle device of the.

[0033] Identical elements, by structure or function, appearing in different figures retain, unless otherwise specified, the same references.

[0034] The hands-free system Sys for automatic access and starting for vehicle V according to the invention is described with reference to figures 1 and 2. In a non-limiting embodiment, the vehicle V (illustrated in the) is a motor vehicle. By motor vehicle is meant any type of motorized vehicle, whether it is a vehicle with a thermal engine, an electric motor or even a hybrid. This embodiment is taken as a non-limiting example in the remainder of the description. In the remainder of the description, the vehicle V is thus otherwise called a motor vehicle V.

[0035] As illustrated in the, the hands-free system Sys includes:- a hands-free identifier Id, and- a vehicle device Disp.

[0036] The elements of the hands-free system Sys are described in detail below, starting with the hands-free identifier Id.

[0037] The hands-free identifier Id allows automatic access and starting of the motor vehicle V without the user having to take the identifier Id out of their bag or pocket, for example. This function is known to those skilled in the art under the acronym PEPS for "Passive Entry Passive Start" in English.

[0038] Conventionally, the hands-free identifier Id is configured to be in an ADV announcement mode, otherwise called ADV broadcast mode and “Advertising Mode” in English, or in an SCN scanning mode otherwise called listening mode and “Scanning Mode” in English. In ADV announcement mode, the hands-free identifier Id can transmit ADV_ev events periodically on primary channels Cx1 which are communication channels. In SCN scanning mode, the hands-free identifier Id can receive events (not shown) from the motor vehicle V. For this purpose, it periodically scans the primary channels Cx1.

[0039] As illustrated in the, the hands-free identifier Id includes a first BlueTooth Low Energy communication module TM , otherwise called first BLE communication module or first BLE module in the rest of the description and referenced M_BLE1 on the.

[0040] In a non-limiting embodiment, the hands-free identifier Id further comprises a second Ultra Wide Band communication module, otherwise called second UWB communication module or second UWB module in the remainder of the description and referenced M_UWB1 on the.

[0041] The hands-free identifier Id further comprises a battery B (illustrated in the) configured to in particular power the first BLE communication module M_BLE1 and the second UWB communication module M_UWB1. In a non-limiting example, the battery is a button cell.

[0042] The first BLE communication module M_BLE1 is configured to transmit ADV_ev events according to a BLE communication protocol (illustrated function f10(M_BLE1, ADV_ev(Adv_ext)) on the) when the hands-free identifier Id is in an ADV announcement mode. It is recalled that the BLE communication protocol uses three primary channels Cx1 numbered 37, 38 and 39 (illustrated on the) and that it uses as BLE frequency band the ISM frequency band of 2.4 GHz. As illustrated on the, an ADV_ev event comprises a plurality of primary frames Adv_ext which are sent on the three primary channels Cx1.

[0043] An Adv_ext primary frame includes a location indication i1 indicating where a first Aux_Adv auxiliary frame is located (illustrated in the figure). A Cx2 secondary channel is otherwise known as a Cx2 extended auxiliary channel. In the BLE communication protocol, Cx2 secondary channels are the channels numbered between 1 and 36. This location indication i1 allows the vehicle device Disp to know which Cx2 secondary channel it will be able to synchronize to in order to retrieve a first Aux_Adv auxiliary frame. In a non-limiting example, the location indication i1 is an offset. Thus, depending on the Adv_ext primary frames sent on the different Cx1 primary channels, the offset i1 will be different.

[0044] The vehicle device Disp starts scanning using the synchronization index Idx and does so during a reduced scanning window Sc_w, namely the time to receive the auxiliary synchronization frame Aux_Sync. It stops scanning at the end of the reception of said auxiliary synchronization frame Aux_Sync.

[0045] The primary Adv_ext frames are transmitted in a first Adv_Int time interval illustrated in the figure. In a non-limiting example, this first Adv_Int time interval is between 3 and 4 seconds. This saves the power of the battery B of the hands-free identifier Id.

[0046] As illustrated in the, the transmission of an ADV_ev event is spaced from the transmission of another ADV_ev event by a period of time Adv_Del. In a non-limiting embodiment, this period of time Adv_Del is of random value, namely non-periodic. This avoids having collisions between primary frames Adv_ext sent by different hands-free identifiers Id. In a non-limiting example, the random value of the period of time Adv_Del is between 0 and 10 milliseconds (ms).

[0047] The first BLE module M_BLE1 is further configured to:- transmit the first auxiliary frame Aux_Adv on a secondary channel Cx2 (illustrated function f11(M_BLE1, Aux_Adv, Cx2), and- transmit the second auxiliary synchronization frames Aux_Sync on secondary channels Cx2 (illustrated function f12(M_BLE1, Aux_Sync, Cx2) so that the vehicle device Disp synchronizes said second auxiliary synchronization frames Aux_Sync.

[0048] Note that the transmission time of the second auxiliary synchronization frames Aux_Sync corresponds to the scanning window Sc_w of the vehicle device Disp.

[0049] The first auxiliary frame Aux_Adv includes a synchronization index Idx with second auxiliary synchronization frames Aux_Sync. This synchronization index Idx allows the motor vehicle V to synchronize with the transmission of the second auxiliary synchronization frames Aux_Sync to retrieve them.

[0050] The synchronization index Idx is indicative of a second time interval Sync_Int (illustrated in the) separating the transmission of two second consecutive auxiliary synchronization frames Aux_Sync. In a non-limiting embodiment, the synchronization index Idx is a hexadecimal number, and in memory of the hands-free identifier Id, a second time interval Sync_Int is associated with each synchronization index Idx. In another non-limiting embodiment, the synchronization index Idx directly indicates the value of the second time interval Sync_Int. The second time interval Sync_Int is periodic.

[0051] Thus, the first auxiliary frame Aux_Adv tells the motor vehicle V when to find the second auxiliary synchronization frames Aux_Sync. The second auxiliary synchronization frames Aux_Sync are thus transmitted after the first auxiliary frame Aux_Adv on also Cx2 data channels.

[0052] The first BLE module M_BLE1 is further configured to receive, after synchronization, a BLE connection request CN_Rq from said motor vehicle V (illustrated function f13(M_BLE1, V, CN_Rq) on the) following estimation of a first distance d1, called BLE distance, indicating whether the hands-free identifier Id is within a BLE range relative to the motor vehicle V. The BLE range can be up to 100 meters. Thus, the first distance d1 can be up to 100 meters.

[0053] The first BLE module M_BLE1 is further configured to be connected to the motor vehicle V in BLE following the reception of this BLE connection request CN_Rq (illustrated function f14(M_BLE1, V, Cnx_BLE).

[0054] It should be noted that the hands-free identifier Id is in a connectable mode to be connected by a third BLE communication module of the motor vehicle V described later.

[0055] In a non-limiting embodiment, the distance estimation d1 is done from one or more RSSI (“Received Signal Strength Indicator” measurements). Since an RSSI measurement is known to those skilled in the art, it is not described here.

[0056] An RSSI measurement makes it possible to estimate the distance between the hands-free identifier Id and the motor vehicle V. This confirms whether the hands-free identifier Id is within the BLE range of the motor vehicle V. If so, the hands-free identifier Id and the motor vehicle V can establish a BLE connection. The BLE connection allows for UWB communication to make a UWB distance measurement, which is more accurate than a distance estimation via the RSSI measurement(s). Without a BLE connection, there can be no UWB communication.

[0057] In a non-limiting embodiment, an RSSI measurement is carried out by the first BLE communication module M_BLE1 (illustrated function f15(M_BLE1, RSSI) on the).

[0058] To perform these functions f10 to f15, the first BLE communication module M_BLE1 comprises a first electronic control unit Ecu1 which is coupled to one or more BlueTooth Low Energy transmitting / receiving antennas TM referenced TxRx1 on which are part of the first BLE communication module M_BLE1.

[0059] The second UWB communication module M_UWB1 is configured to, following the BLE connection with said motor vehicle V, receive UWB signals referenced s_UWB from said motor vehicle V for a UWB distance measurement of said hands-free identifier Id relative to said motor vehicle V (illustrated function f20(M_UWB1, V, s_UWB) on the). The UWB signals are received when the hands-free identifier Id is within a UWB range relative to the motor vehicle V. The UWB range is less than 10 meters. The UWB distance is a second distance d2. It is thus measured when the hands-free identifier Id is within the UWB range relative to the motor vehicle V, namely at a distance of less than 10 meters around the motor vehicle V. Upon receipt of the UWB signals s_UWB, the second UWB communication module M_UWB1 is further configured to return UWB return signals s'_UWB (illustrated function f21(M_UWB1, V, s'_UWB).UWB distance measurement is performed if the hands-free identifier Id is within the UWB range around the motor vehicle V. Indeed, there can be no UWB distance measurement if the hands-free identifier Id is outside the UWB range.

[0060] The UWB distance measurement is made by the motor vehicle V and is based on a calculation of the time difference between the transmitted UWB signal and the returned UWB signal. This gives an accurate measurement of the second distance d2 of the hands-free identifier Id from the motor vehicle V when it is within the UWB range.

[0061] When the hands-free identifier Id is within the UWB distance, in this case, access to the motor vehicle V can be authorized. Thus, the doors of the motor vehicle V can be unlocked in a non-limiting example. Since a UWB distance measurement is known to those skilled in the art, it is not described here.

[0062] To perform these functions f20 and f21, the second UWB communication module M_UWB1 comprises a second electronic control unit Ecu2 coupled to one or more Ultra Wide Band transmitting / receiving antennas referenced TxRx2 on which are part of the second UWB communication module M_UWB1.

[0063] The elements of the vehicle device Disp are now described below. In a non-limiting embodiment, the vehicle device Disp is part of the motor vehicle V.

[0064] As illustrated in the, the vehicle device Disp includes a third BLE communication module otherwise called third BLE module and referenced M_BLE2.

[0065] In a non-limiting embodiment, the vehicle device Disp further comprises a fourth UWB communication module otherwise called fourth UWB module and referenced M_UWB2.

[0066] The motor vehicle V is initially positioned in a SCN scanning mode to receive ADV_ev events. This positioning is carried out by the manufacturer of the motor vehicle V which manages the hands-free identifiers Id associated with the motor vehicle V.

[0067] The third BLE communication module M_BLE2 is configured to:- scan the ADV_ev events emitted by the hands-free identifier Id according to the BLE communication protocol when said vehicle V is in a SCN scanning mode (illustrated function f31(M_BLE2, Id, ADV_ev(Adv_ext)) on the),- search for a first auxiliary frame Aux_Adv from the location indication i1 found in a primary frame Adv_ext emitted on the primary channels Cx1 (illustrated function f32(M_BLE2, Aux_Adv, Cx2, i1) on the).

[0068] It will be noted that the reception of ADV_ev events and in particular of Adv_ext primary frames on the different primary channels Cx1, here 37, 38 and 39, is based on a scanning interval Sc_Int called in English "Scan interval" and on a scanning window Sc_w called in English "Scan window" illustrated on the. The scanning interval Sc_Int defines at which intervals the motor vehicle V begins scanning and the scanning window Sc_w defines the scanning time during each scanning interval Sc_Int. The ratio between the two Sc_w / Sc_Int defines a duty cycle.

[0069] In the non-limiting example of primary channels 37, 38 and 39, during a first scanning interval Sc_Int and during a first scanning window Sc_w, the third BLE communication module M_BLE2 will listen to the primary channel 37 to retrieve the primary Adv_ext frames transmitted on this primary channel 37. During a second scanning time interval Sc_Int and during a second scanning window Sc_w, the third BLE communication module M_BLE2 will listen to the primary channel 38 to retrieve the primary Adv_ext frames transmitted on this primary channel 38. And, during a third scanning time interval Sc_Int and during a third scanning window Sc_w, the third BLE communication module M_BLE2 will listen to the primary channel 39 to retrieve the primary Adv_ext frames transmitted on this primary channel 39.

[0070] If the location indication i1 indicates that there is a first auxiliary frame Aux_Adv, then the vehicle device Disp will be able to perform a synchronized scan.

[0071] For this purpose, the third BLE communication module M_BLE2 is further configured to:- decode said first auxiliary frame Aux_Adv to extract the synchronization index Idx (illustrated function f33(M_BLE2, Aux_Adv, Idx) on the), and- depending on said synchronization index Idx, synchronize with the second auxiliary synchronization frames Aux_Sync (illustrated function f34(M_BLE2, Aux_Sync, Idx) on the).

[0072] Synchronization is a synchronization of the SCN scanning mode of the motor vehicle V with the second auxiliary synchronization frames Aux_Sync. Since it knows the second time interval Sync_Int separating the transmission of two consecutive second auxiliary synchronization frames Aux_Sync, the third BLE communication module M_BLE2 sets the SCN scanning mode of the motor vehicle V to the transmission of these second auxiliary synchronization frames Aux_Sync. Thus, the third BLE communication module M_BLE2 modifies its scanning interval Sc_Int with the second time interval Sync_Int so that it has the same value. Thus, since the second time interval Sync_Inc is periodic, the scanning interval Sc_Int becomes periodic whereas previously it was random non-periodic. It also modifies its scanning window Sc_w by setting it to the transmission time of a second auxiliary synchronization frame Aux_Sync.

[0073] Still in scanning mode, SCN, and as it has synchronized with the transmission of the second auxiliary synchronization frames Aux_Sync, the third BLE communication module M_BLE2 can thus trigger a distance estimation d1 more quickly. The latter is therefore more efficient in seeing if the hands-free identifier Id is within the BLE range around the motor vehicle V.

[0074] Thus, after synchronization, the third BLE communication module M_BLE2 can perform a distance estimation d1 from one or more RSSI measurements.

[0075] In a non-limiting embodiment, an RSSI measurement is made on the hands-free identifier Id side and an RSSI measurement is made on the motor vehicle V side.

[0076] Thus, after synchronization, the third BLE communication module M_BLE2 is further configured to perform one or more RSSI measurements (illustrated function f35(M_BLE2, RSSI) on the) and perform a distance estimation d1 from the RSSI measurement(s) (illustrated function f36(M_BLE2, d1, RSSI) on the). The distance estimation d1 indicates whether said hands-free identifier Id is within BLE range relative to said vehicle.

[0077] When the hands-free identifier Id is within the BLE range, the third BLE communication module M_BLE2 is further configured to:- after said distance estimation, issue a connection request CN_Rq (illustrated function f37(M_BLE2, CN_Rq) on the) according to the BLE communication protocol following said distance estimation d1, and- perform the BLE connection with said hands-free identifier Id (illustrated function f38(M_BLE2, Id, Cnx_BLE) on the).

[0078] Note that it is the motor vehicle V which in this case connects the hands-free identifier Id. It initiates the connection by sending said connection request CN_Rq to the hands-free identifier Id.

[0079] To perform these functions f31 to f38, the third BLE communication module M_BLE2 includes a third electronic control unit Ecu3 coupled to one or more BlueTooth Low Energy transmitting / receiving antennas TM referenced TxRx3 on the.

[0080] When the hands-free identifier Id and the motor vehicle V are connected via BLE, UWB distance measurement can be performed.

[0081] The fourth UWB communication module M_UW2 is configured to:- transmit UWB signals s_UWB for the UWB distance measurement of said hands-free identifier Id relative to the motor vehicle V (illustrated function f39(M_UW2, s_UWB) on the), and- receive in return UWB return signals s'_UWB transmitted by the hands-free identifier Id (illustrated function f40(M_UW2, s'_UWB) on the).

[0082] The fourth UWB communication module M_UW2 is further configured to calculate the second distance d2, called UWB distance, of the hands-free identifier Id relative to the motor vehicle V (illustrated function f41(M_UW2, d2) on the).

[0083] To perform these functions f39 to f41, the fourth UWB communication module M_UW2 comprises a fourth electronic control unit Ecu4 coupled to one or more Ultra Wide Band transmitting / receiving antennas referenced TxRx4 on the.

[0084] The hands-free system Sys described above makes it possible to implement a Pro0 location method of a hands-free access and automatic start identifier Id in relation to a motor vehicle V, said Pro0 location method being illustrated in the.

[0085] The localization method Pro0 comprises an initial step E0 illustrated F0(Id, ADV) on which the first BLE communication module M_BLE1 positions the hands-free identifier Id in the ADV announcement mode.

[0086] In a step E1 illustrated F1(Id(M_BLE1), ADV_ev), the hands-free identifier Id transmits via its first BLE communication module M_BLE1 the ADV_ev events according to the BLE communication protocol, an ADV_ev event comprising a plurality of primary frames Adv_ext transmitted on primary channels Cx1, a primary frame Adv_ext comprising a location indication i1 indicating the location where a first auxiliary frame Aux_Adv is located, said first auxiliary frame Aux_Adv comprising a synchronization index Idx with second auxiliary synchronization frames Aux_Sync.

[0087] In a step E2 illustrated F2(Id(M_BLE1), Aux_Adv), the hands-free identifier Id transmits via its first BLE communication module M_BLE1 following the transmission of the three primary frames Adv_ext on the three primary channels 37, 38, 39 the first auxiliary frame Aux_Adv on a secondary channel Cx2 according to the BLE communication protocol.

[0088] In a step E3 illustrated F3(Id(M_BLE1), Aux_Sync), the hands-free identifier Id starts a periodic ADV announcement mode and thus transmits following the first auxiliary frame Aux_Adv the second auxiliary synchronization frames Aux_Sync using the second time interval Sync_Int which is periodic.

[0089] Note that we can have an alternation of primary Adv_ext frame and second auxiliary synchronization frames Aux_Sync given that the Adv_Del time period is random.

[0090] In an illustrated step E4 F4(Disp(M_BLE2), ADV_ev), the vehicle device Disp via its third BLE communication module M_BLE2 scans the ADV_ev events and retrieves the location indication i1 in a primary frame Adv_ext. Such a scan of ADV_ev events being known to those skilled in the art, it is not described here.

[0091] In a step E5 illustrated F5(Disp(M_BLE2), Aux_Adv, Cx2, i1), the vehicle device Disp via its third BLE communication module M_BLE2 searches for the first auxiliary frame Aux_Adv in said secondary channel Cx2 from said location indication i1.

[0092] When it has retrieved the first auxiliary frame Aux_Adv, in a step E6 illustrated F6(Disp(M_BLE2), Aux_Adv, Cx2, i1), the vehicle device Disp via its third BLE communication module M_BLE2 decodes the first auxiliary frame Aux_Adv to extract the synchronization index Idx.

[0093] Depending on said synchronization index Idx, in a step E7 illustrated F7(Disp (M_BLE2), Aux_Sync, Idx), the vehicle device Disp via its third BLE communication module M_BLE2 synchronizes with the second auxiliary synchronization frames Aux_Sync. Thus, the SCN scanning mode becomes synchronized with the broadcast of the auxiliary synchronization frames Aux_Sync. As the vehicle device Disp has aligned itself with these second auxiliary synchronization frames Aux_Sync, it can retrieve the data that is in it. The vehicle device Disp thus consumes less and has a controlled BLE connection time. It should be noted that there is no impact of BLE connection time with the hands-free identifier Id.

[0094] Synchronization allows RSSI measurements to be made periodically and therefore synchronized. Note that in the case where the scanning interval Sc_Int is small compared to when it was random and not periodic, then the vehicle device Disp can make more RSSI measurements which allows for a more reliable distance measurement d1. Furthermore, the vehicle device Disp can have more time to manage other connections with other electronic devices.

[0095] In a non-limiting example, the scan interval Sc_Int when periodic is equal to 50 milliseconds and when not periodic it is equal to 1 second plus a random time. In this case, in a non-limiting example, the vehicle device Disp will scan for 2 milliseconds every 50 milliseconds. Thus, the scanning is periodic. Otherwise, the scanning is arbitrary.

[0096] In a step E8 illustrated F8(Disp(M_BLE2), RSSI), after synchronization, the vehicle device Disp via its third BLE communication module M_BLE2 performs one or more RSSI measurements.

[0097] In a step E9 illustrated F9(Disp(M_BLE2), d1, RSSI), the vehicle device Disp via its third BLE communication module M_BLE2 estimates a distance d1 from one or more RSSI measurements. If applicable, it has also retrieved an RSSI distance measurement made on the hands-free identifier Id side. It will be noted that the retrieval of the RSSI distance measurement from the hands-free identifier Id can be done during a scanning request otherwise called in English "Scan Request" well known to those skilled in the art and a return response to this scanning request returned by the hands-free identifier Id, a return response well known to those skilled in the art and otherwise called in English "Scan Response" and which includes the RSSI measurement.

[0098] When the distance estimation d1 indicates that the hands-free identifier Id is within the BLE range, in a step E10 illustrated F10(Disp(M_BLE2), CN_Rq), the vehicle device Disp via its third BLE communication module M_BLE2 issues a BLE connection request CN_Rq to perform a BLE connection with said hands-free identifier Id, which BLE connection request CN_Rq is received by the hands-free identifier Id via its first BLE communication module M_BLE1 (step E10' illustrated F10'(Id(M_BLE1), CN_Rq).

[0099] In a step E11 illustrated F11(Id(M_BLE1), Disp(M_BLE2), Cnx_BLE), the vehicle device Disp via its third BLE communication module M_BLE2 makes a BLE connection with the hands-free identifier Id via its first BLE communication module M_BLE1. Thus, thanks to the synchronization described previously, if the periodic scanning interval Sc_Int is smaller than when it was random and not periodic, the vehicle device Disp can connect more quickly in BLE to the identifier Id. It will therefore have a reduced radiofrequency activity linked to the search for the identifier Id.

[0100] In a non-limiting embodiment, following the BLE connection, in a step E12 illustrated F12(Disp(M_UWB2), s_UWB)), the vehicle device Disp via its fourth UWB communication module M_UWB2 transmits UWB signals s_UWB for a UWB distance measurement (namely the second distance d2), of said hands-free identifier Id relative to the motor vehicle V, UWB signals s_UWB which are received by the hands-free identifier Id via its second UWB communication module M_UWB1 (step E12' illustrated F12'(Id(M_UWB1), s_UWB)). It will be noted that without a BLE connection, the UWB signals cannot be sent. It will be noted that the transmission of the UWB signals s_UWB is done only if the identifier Id is in the UWB range relative to the motor vehicle V.

[0101] In a step E13 illustrated F13(Id(M_UWB1), s'_UWB)), the hands-free identifier Id via its second UWB module M_UWB1 returns UWB return signals s'_UWB which are received by the vehicle device Disp via its fourth UWB module M_UWB2 (step E13' illustrated F13'(Disp(M_UWB2), s'_UWB)).

[0102] In a step E14 illustrated F14(Disp(M_UWB2), UWB(d2)), the vehicle device Disp via its fourth UWB module M_UWB2 performs a UWB distance measurement based on the transmitted UWB signals s_UWB and the returned UWB return signals s'_UWB.

[0103] If the UWB distance measurement indicates that the hands-free identifier Id is within the UWB range, namely at a second distance d2 of less than 10 meters, then the motor vehicle V can perform the following operations in non-limiting examples: - automatic opening of the doors, or - automatic opening of the tailgate or trunk.

[0104] Note that when the BLE connection is disabled (e.g. when the hands-free identifier goes out of BLE range), the Disp vehicle device reverts to an unsynchronized SCN scanning mode.

[0105] Thus, as illustrated in the, a first method of communication Pro1 with said vehicle device Disp is implemented by the hands-free identifier Id for its location relative to the motor vehicle V.

[0106] The first Pro1 communication process includes the following steps.

[0107] In a step E1 illustrated F1(Id(M_BLE1), ADV_ev), the hands-free identifier Id transmits via its first BLE communication module M_BLE2 the ADV_ev events according to the BLE communication protocol, an ADV_ev event comprising a plurality of primary frames Adv_ext transmitted on primary channels Cx1, a primary frame Adv_ext comprising a location indication i1 indicating the location where a first auxiliary frame Aux_Adv is located, said first auxiliary frame Aux_Adv comprising a synchronization index Idx with second auxiliary synchronization frames Aux_Sync.

[0108] In a step E2 illustrated F2(Id(M_BLE1), Aux_Adv), the hands-free identifier Id transmits via its first BLE communication module M_BLE1 following the transmission of the three primary frames Adv_ext on the three primary channels 37, 38, 39 the first auxiliary frame Aux_Adv on a secondary channel Cx2 according to the BLE communication protocol.

[0109] In a step E3 illustrated F3(Id(M_BLE1), Aux_Sync), the hands-free identifier Id starts a periodic ADV announcement mode and thus transmits the second auxiliary synchronization frames Aux_Sync using the second time slot Sync_Int which is periodic.

[0110] In a step E10' illustrated F10'(Id(M_BLE1), CN_Rq), the hands-free identifier Id via its first BLE communication module M_BLE1 receives a BLE connection request CN_Rq issued by the vehicle device Disp to perform a BLE connection.

[0111] In a step E11 illustrated F11(Id(M_BLE1), Disp(M_BLE2), Cnx_BLE), the hands-free identifier Id via its first BLE communication module M_BLE1 makes a BLE connection with the vehicle device Disp.

[0112] In a non-limiting embodiment, following the BLE connection, in a step E12' illustrated F12'(Id(M_UWB1), s_UWB), the hands-free identifier Id via its second UWB communication module M_UWB1 receives UWB signals s_UWB emitted by the vehicle device Disp for a UWB distance measurement of said hands-free identifier Id relative to the motor vehicle V.

[0113] In a step E13 illustrated F13(Id(M_UWB1), s'_UWB)), the hands-free identifier Id via its second UWB module M_UWB1 sends back UWB return signals s'_UWB which will be used for UWB distance measurement.

[0114] It should be noted that the numbering of the steps is the same as that used in the Pro0 localization process since the steps of the first Pro1 communication process are part of the Pro0 localization process.

[0115] Thus, as illustrated in the, a second communication method Pro2 with said hands-free identifier Id is implemented by the vehicle device Disp for locating said hands-free identifier Id relative to the motor vehicle V.

[0116] The second Pro2 communication method includes the following steps.

[0117] In a step E4 illustrated F4(Disp(M_BLE2), ADV_ev), the vehicle device Disp via its third BLE communication module M_BLE2 scans ADV_ev events transmitted by the hands-free identifier Id, an ADV_ev event comprising a plurality of primary frames Adv_ext transmitted on primary channels Cx1, a primary frame Adv_ext comprising a location indication i1 indicating the location of a first auxiliary frame Aux_Adv, said first auxiliary frame Aux_Adv comprising a synchronization index Idx with second auxiliary synchronization frames Aux_Sync. The vehicle device Disp thus recovers the frames Adv_Ext and the location indication i1. It will be noted that the time interval between two Adv_Ext is not periodic.

[0118] In a step E5 illustrated F5(Disp(M_BLE2), Aux_Adv, Cx2, i1), the vehicle device Disp via its third BLE communication module M_BLE2 searches for the first auxiliary frame Aux_Adv in said secondary channel Cx2 from said location indication i1.

[0119] When it has retrieved the first auxiliary frame Aux_Adv, in a step E6 illustrated F6(V(M_BLE2), Aux_Adv, Idx), the vehicle device Disp via its third BLE communication module M_BLE2 decodes the first auxiliary frame Aux_Adv to extract the synchronization index Idx.

[0120] Depending on said synchronization index Idx, in a step E7 illustrated F7(Disp(M_BLE2), Aux_Sync, Idx), the vehicle device Disp via its third BLE communication module M_BLE2 synchronizes with the second auxiliary synchronization frames Aux_Sync. As the vehicle device Disp has aligned with these second auxiliary synchronization frames Aux_Sync, it can retrieve the data that is therein.

[0121] In a step E8 illustrated F8(Disp(M_BLE2), RSSI), the vehicle device Disp via its third BLE communication module M_BLE2 performs one or more RSSI measurements.

[0122] In a step E9 illustrated F9(V(M_BLE2), d1, RSSI), the vehicle device Disp via its third BLE communication module M_BLE2 estimates a distance d1 from one or more RSSI measurements. To this end, it has previously carried out an RSSI distance measurement and retrieved, if necessary, an RSSI distance measurement made on the hands-free identifier side Id.

[0123] When the distance estimation d1 indicates that the hands-free identifier Id is within the BLE range, in a step E10 illustrated F10(Disp(M_BLE2), CN_Rq), after said distance estimation d1, the vehicle device Disp via its third BLE communication module M_BLE2 issues a BLE connection request CN_Rq to perform a BLE connection with said hands-free identifier Id.

[0124] In a step E11 illustrated F11(Id(M_BLE1), Disp(M_BLE2), Cnx_BLE), the vehicle device Disp via its third BLE communication module M_BLE2 makes a BLE connection with the hands-free identifier Id via its first BLE communication module M_BLE1.

[0125] In a non-limiting embodiment, following the BLE connection, in a step E12 illustrated F12(V(M_UWB2), s_UWB)), the vehicle device Disp via its fourth UWB communication module M_UWB2 transmits UWB signals s_UWB for a UWB distance measurement of said hands-free identifier Id in the UWB range relative to the motor vehicle V.

[0126] In a step E13' illustrated F13'(Disp(M_UWB2), s'_UWB)), the vehicle device Disp via its fourth UWB module M_UWB2 receives in return UWB return signals s'_UWB emitted by the hands-free identifier Id.

[0127] In a step E14 illustrated F14(Disp(M_UWB2), UWB(d2))), the vehicle device Disp via its fourth UWB module M_UWB2 carries out a UWB distance measurement from the UWB signals s_UWB that it has emitted and the return signals s'_UWB emitted by the hands-free identifier Id.

[0128] It should be noted that the numbering of the steps is the same as that used in the Pro0 localization process since the steps of the second Pro2 communication process are part of the Pro0 localization process.

[0129] Of course, the description of the invention is not limited to the application and embodiments described above and to the field described above.

[0130] Thus, the invention described presents in particular the following advantages: - it makes it possible to save the energy consumed by the vehicle device Disp since the latter only listens for the necessary time without this having an impact on the BLE connection time.

Claims

Hands-free system (Sys) for automatic access and starting for a vehicle (V), said hands-free system (Sys) comprising:a) a hands-free identifier (Id) comprising a first BLE communication module (M_BLE1) configured to transmit events (ADV_ev) according to a BLE communication protocol when said hands-free identifier (Id) is in an announcement mode (ADV), an event (ADV_ev) comprising a plurality of primary frames (Adv_ext) transmitted on primary channels (Cx1),b) a vehicle device (Disp) comprising a third BLE communication module (M_BLE2) configured to scan said events (ADV_ev) transmitted by said hands-free identifier (Id) when said vehicle (V) is in a scanning mode (SCN),Characterized in that:c) a primary frame (Adv_ext) comprises a location indication (i1) indicating the location of a first auxiliary frame (Aux_Adv),said first auxiliary frame (Aux_Adv) comprising a synchronization index (Idx) with second auxiliary synchronization frames (Aux_Sync), and in that: d) said first BLE communication module (M_BLE1) is further configured to: - transmit said first auxiliary frame (Aux_Adv) and said second auxiliary synchronization frames (Aux_Sync) on secondary channels (Cx2) so that the vehicle device (Disp) synchronizes said second auxiliary synchronization frames (Aux_Sync), and - receive after said synchronization a BLE connection request (CN_Rq) from said vehicle device (Disp) following a distance estimation (d1) indicating whether said hands-free identifier (Id) is within BLE range relative to said vehicle (V),and in that:e) said third BLE communication module (M_BLE2) is further configured to:- search for said first auxiliary frame (Aux_Adv) in a secondary channel (Cx2) from said location indication (i1),- decode said first auxiliary frame (Aux_Adv) to extract the synchronization index (Idx), and- depending on said synchronization index (Idx) synchronize with the second auxiliary synchronization frames (Aux_Sync),- after said synchronization, perform one or a plurality of RSSI measurements and perform a distance estimation (d1) from said plurality of RSSI measurements,- after said distance estimation (d1), transmit said BLE connection request (CN_Rq) to perform a BLE connection with said hands-free identifier (Id) following said distance estimation (d1) indicating whether said hands-free identifier (Id) is within BLE range relative to said vehicle (V)., Hands-free access system (Sys) according to claim 1, wherein said primary frames (Adv_ext) are transmitted in a first time interval (Adv_Int). A hands-free access system (Sys) according to claim 1 or claim 2, wherein a first time interval (Adv_Int) is spaced from another first time interval (Adv_Int) by a time period (Adv_Del) of random value. Hands-free access system (Sys) according to any one of the preceding claims, wherein said synchronization index (Idx) is indicative of a second time interval (Sync_Int) separating the transmission of two second consecutive auxiliary synchronization frames (Aux_Sync). Hands-free access system (Sys) according to any one of the preceding claims, wherein said second time interval (Sync_Int) is periodic. Hands-free access system (Sys) according to any one of the preceding claims, wherein said synchronization is a synchronization of the scanning mode (SCN) with said second auxiliary synchronization frames (Aux_Sync). Hands-free access system (Sys) according to any one of the preceding claims, wherein:a) said hands-free identifier (Id) further comprises a second UWB communication module configured to, after the BLE connection, receive UWB signals (s_UWB) from said vehicle device (Disp) for a UWB distance measurement (d2) relative to said vehicle (V), and transmit in return UWB return signals (s'_UWB) for said UWB distance measurement (d2), andb) said vehicle device (Disp) further comprises a fourth UWB communication module (M_UWB2) configured to, after the BLE connection, transmit said UWB signals (s_UWB), to receive said UWB return signals (s'_UWB), and to perform said UWB distance measurement (d2) from said UWB signals (s_UWB) and said UWB return signals (s'_UWB). A method of locating (Pro0) a hands-free identifier (Id) for access and automatic start for a vehicle (V) relative to a vehicle (V), said hands-free identifier (Id) comprising a first BLE communication module (M_BLE1) and said vehicle (V) comprising a vehicle device (Disp), the latter comprising a third BLE communication module (M_BLE2), characterized in that said locating method (Pro0) comprises: - a transmission by said first BLE communication module (M_BLE1) of events (ADV_ev) according to a BLE communication protocol when said hands-free identifier (Id) is in an announcement mode (ADV), and a reception by said third BLE communication module (M_BLE2) of said events (ADV_ev) when said vehicle (V) is in a scanning mode (SCN), an event (ADV_ev) comprising a plurality of primary frames (Adv_ext) transmitted on primary channels (Cx1),a primary frame (Adv_ext) comprising a location indication (i1) indicating the location of a first auxiliary frame (Aux_Adv), said first auxiliary frame (Aux_Adv) comprising a synchronization index (Idx) with second auxiliary synchronization frames (Aux_Sync),- a transmission by said first BLE communication module (M_BLE1) of said first auxiliary frame (Aux_Adv) and said second auxiliary synchronization frames (Aux_Sync) on secondary channels (Cx2) so that said vehicle device (Disp) synchronizes said second auxiliary synchronization frames (Aux_Sync),- a scan by said third BLE communication module (M_BLE2) of said events (ADV_ev) to extract said location indication (i1),- a search by said third BLE communication module (M_BLE2) of said first auxiliary frame (Aux_Adv) in a secondary channel (Cx2) from said location indication (i1),- a decoding by said third BLE communication module (M_BLE2) of said first auxiliary frame (Aux_Adv) to extract therefrom said synchronization index (Idx), and- depending on said synchronization index (Idx), a synchronization by said third BLE communication module (M_BLE2) with said second auxiliary synchronization frames (Aux_Sync),- after said synchronization, a performance by said third BLE communication module (M_BLE2) of one or more RSSI measurements and a distance estimation (d1) by said third BLE communication module (M_BLE2) from said one or more RSSI measurements,- after said distance estimation (d1),a transmission by said third BLE communication module (M_BLE2) of a BLE connection request (CN_Rq) following said distance estimation (d1) indicating whether said hands-free identifier (Id) is within BLE range relative to said vehicle (V), and a reception by said first BLE communication module (M_BLE1) of said BLE connection request (CN_Rq), - a BLE connection between said hands-free identifier (Id) and said vehicle device (Disp)., Hands-free identifier (Id) for access and automatic start for vehicle (V) comprising a first BLE communication module (M_BLE1) configured to transmit events (ADV) according to a BLE communication protocol when said hands-free identifier (Id) is in an announcement mode (ADV), an event (ADV_ev) comprising a plurality of primary frames (Adv_ext) transmitted on primary channels (Cx1),Characterized in that:a) a primary frame (Adv_ext) comprises a location indication (i1) indicating the location where a first auxiliary frame (Aux_Adv) is located, said first auxiliary frame (Aux_Adv) comprising a synchronization index with second auxiliary synchronization frames (Aux_Sync),and in that:b) said first BLE communication module (M_BLE1) is further configured to:- transmit said first auxiliary frame (Aux_Adv) and said second auxiliary synchronization frames (Aux_Sync) on secondary channels (Cx2) so that said vehicle device (Disp) synchronizes with said second auxiliary synchronization frames (Aux_Sync), and- receive after said synchronization a BLE connection request (CN_Rq) from said vehicle device (Disp) following a distance estimation (d1) indicating whether said hands-free identifier (Id) is within BLE range relative to said vehicle (V)., Hands-free identifier (Id) according to the preceding claim, wherein said hands-free identifier (Id) further comprises a second UWB communication module (M_UWB2) configured to, after the BLE connection:- receive UWB signals (s_UWB) from said vehicle (V) for a UWB distance measurement (d2) relative to said vehicle (V),- transmit in return UWB return signals (s'_UWB) for said UWB distance measurement (d2). First method of communicating (Pro1) a hands-free identifier (Id) for access and automatic start for a vehicle (V) with a vehicle device (Disp) for its location relative to said vehicle (V), said hands-free identifier (Id) comprising a first BLE communication module (M_BLE1), characterized in that said first communication method (Pro1) comprises: - a transmission by said first BLE communication module (M_BLE1) of events (ADV_ev) according to a BLE communication protocol when said hands-free identifier (Id) is in an announcement mode (ADV), an event (ADV_ev) comprising a plurality of frames (Adv_ext) transmitted on primary channels (Cx1), a frame (Adv_ext) comprising a location indication (i1) indicating the location where a first auxiliary frame (Aux_Adv) is located,said first auxiliary frame (Aux_Adv) comprising a synchronization index (Idx) with second auxiliary synchronization frames (Aux_Sync),- a transmission by said first BLE communication module (M_BLE1) of a first auxiliary frame (Aux_Adv) and said second auxiliary synchronization frames (Aux_Sync) on secondary channels (Cx2) so that a vehicle device (Disp) synchronizes said second auxiliary synchronization frames (Aux_Sync),- after said synchronization, a reception by said first BLE communication module (M_BLE1) of a BLE connection request (CN_Rq) transmitted by said vehicle device (Disp) following a distance estimation (d1) indicating whether said hands-free identifier (Id) is within a BLE range relative to said vehicle (V),- a BLE connection with said vehicle device (Disp) following the reception of said BLE connection request (CN_Rq)., Vehicle device (Disp) for accessing and automatically starting the vehicle, said device (Disp) comprising a third BLE communication module (M_BLE2) configured to scan events (ADV_ev) transmitted by said hands-free identifier (Id) according to a BLE communication protocol when said vehicle (V) is in a scanning mode (SCN), an event (ADV) comprising a plurality of primary frames (Adv_ext) transmitted on primary channels (Cx1),Characterized in that said third BLE communication module (M_BLE2) is further configured to:- search for a first auxiliary frame (Aux_Adv) in a secondary channel (Cx2) from a location indication (i1) included in a primary frame (Adv_ext),- decode said first auxiliary frame (Aux_Adv) to extract therefrom a synchronization index (Idx), and- depending on the synchronization index (Idx),synchronize with second auxiliary synchronization frames (Aux_Sync) transmitted by said hands-free identifier (Id) on secondary channels (Cx2),- after said synchronization, perform one or a plurality of RSSI measurements and perform a distance estimation (d1) from said plurality of RSSI measurements,- after said distance estimation (d1), transmit said BLE connection request (CN_Rq) to perform a BLE connection with said hands-free identifier (Id) following said distance estimation (d1) indicating whether said hands-free identifier (Id) is within BLE range relative to said vehicle (V),- perform a BLE connection with said hands-free identifier (Id)., Vehicle device (Disp) according to the preceding claim, wherein said synchronization is a synchronization of the scanning mode (SCN) with said second auxiliary synchronization frames (Aux_Sync). Vehicle device (Disp) according to the preceding claim, wherein said vehicle device (Disp) further comprises a fourth UWB communication module (M_UWB2) configured to:- transmit UWB signals (s_UWB) for a UWB distance measurement (d2) of said hands-free identifier (Id) relative to said vehicle (V),- receive in return UWB return signals (s'_UWB) transmitted by a second UWB communication module (M_UWB1) of said hands-free identifier (Id), and- perform said UWB distance measurement (d2). Second method of communication (Pro2) of a vehicle device (Disp) with a hands-free identifier (Id) for access and automatic start for vehicle (V) for the location of said hands-free identifier (Id) relative to said vehicle (V), said vehicle device (Disp) comprising a third BLE communication module (M_BLE2), characterized in that said second method of communication (Pro2) comprises: - a reception by said third BLE communication module (M_BLE2) of events (ADV_ev) transmitted by said hands-free identifier (Id) according to a BLE communication protocol when said vehicle (V) is in a scanning mode (SCN), an event (ADV_ev) comprising a plurality of primary frames (Adv_ext) transmitted on primary channels (Cx1), a primary frame (Adv_ext) comprising a location indication (i1) indicating the location where a first auxiliary frame (Aux_Adv) is located,said first auxiliary frame (Aux_Adv) comprising a synchronization index (Idx) with second auxiliary synchronization frames (Aux_Sync),- a scan by said third BLE communication module (M_BLE2) of said events (ADV_ev) to extract said location indication (i1) therefrom,- a search by said third BLE communication module (M_BLE2) of said first auxiliary frame (Aux_Adv) in a secondary channel (Cx2) from said location indication (i1),- a decoding by said third BLE communication module (M_BLE2) of said first auxiliary frame (Aux_Adv) to extract said synchronization index (Idx), and- depending on said synchronization index (Idx), a synchronization by said third BLE communication module (M_BLE2) with the second auxiliary synchronization frames (Aux_Sync),- after said synchronization,a performance by said third BLE communication module (M_BLE2) of one or a plurality of RSSI measurements and a distance estimation (d1) by said third BLE communication module (M_BLE2) from said plurality of RSSI measurements,- after said distance estimation (d1), a transmission by said third BLE communication module (M_BLE2) of a BLE connection request (CN_Rq) following said distance estimation (d1) indicating whether said hands-free identifier (Id) is within BLE range relative to said vehicle (V),- a BLE connection with said hands-free identifier (Id).,

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