FORM 2
THE PATENTS ACT,
1970 (39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10, rule 13)
“A RESILIENT LOW FREQUENCY-RADIO FREQUENCY BASED PASSIVE KEYLESS ACCESS SYSTEM AND METHOD THEREOF”
MINDA CORPORATION LIMITED, of E-5/2, Chakan Industrial Area, Phase-III, M.I.D.C., Nanekarwadi, Tal: Khed, Dist.Pune-410 501, India
The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD
[001] The present disclosure generally relates to a passive keyless access system
for vehicles. More particularly, but not exclusively, the present disclosure relates to a resilient low frequency-radio frequency (LF-RF) based authentication in the passive keyless access system.
BACKGROUND
[002] Vehicles of modern times embed complex electronic systems to improve
user/driver safety and convenience. Areas of significant public and manufacturer interests include access to the vehicle (i.e., entry in the vehicle) and authorization to drive (i.e., start of the vehicle). Traditionally, the access and authorization have been achieved using physical key and lock systems, where a user was able to enter and drive the vehicle by inserting a correct key into door and ignition locks. In the last decade, this system has been augmented with remote access in which a user is able to open his/her vehicle remotely by pressing a button on an associated key fob. In these systems, the authorization to drive is still mainly enforced by a physical key and lock system.
[003] In the next technological transformation and upgradation over the earlier
authorization system, Passive Entry Passive Start (PEPS) system has been introduced. The PEPS system is deployed not only for four wheelers and multi-wheelers but for two wheelers as well. A PEPS system allows a user/driver to enter and start a vehicle through a wireless authentication process between the vehicle and a paired key fob. The PEPS system is used to lock, unlock, or start the vehicle without user intervention (i.e., without physically using the key fob by insertion into a key hole for cranking the vehicle), when the key fob is in proximity to the vehicle. Additionally, the PEPS system allows the user to control the opening of door, trunk and alarm, in case of four-wheelers.
[004] Four-wheeler vehicles employ an immobilizer system that verifies
legitimacy of the user’s key fob before starting the engine. Immobilizers are usually implemented using a cryptographically enabled Radio-Frequency Identification (RFID)

device embedded in the key fob. While traditionally keyless entry and immobilization were two separate systems, but nowadays these features are combined into a single PEPS system. This allows unlocking the vehicle and disengaging the immobilizer without any user interaction. Immobilizer chips are generally used to avoid key copying. In the immobilizer system, a vehicle communicates with its corresponding key using magnetically coupled Low Frequency signals. In that, a communication channel is established when the key is in close proximity to the vehicle. Most immobilizer systems in the vehicles adopt a challenge-response technique.
[005] Figure 1 shows an exemplary environment 100 illustrating the working of
a passive keyless access system comprising a vehicle 102 and a key fob 104. The passive keyless access system uses two separate frequencies: a low frequency (LF) for short-range communication and an ultra-high frequency (RF) for long range communication. In the challenge-response technique, the vehicle 102 periodically broadcasts a random challenge or wake up signal 106 (also known as LF signal or LF challenge) on the LF channel, comprising a vehicle identifier to find the key fob 104 and instructing the key fob 104 to wake up and accept challenges. The key fob 104 periodically monitors signals on the LF channel. As the communication range of the LF communication is few meters, the key fob 104 wakes up only when it is in the close proximity of the vehicle 102. If the LF signal 106 is detected, the key fob 104 wakes up from the sleep mode. If the received LF signal is successfully decoded, the key fob 104 sends an encrypted response message 108 (or RF response signal) on RF channel using a secret key stored in it. The vehicle 102 verifies the RF response signal 108 from the key fob 104 and unlocks the doors. So, the vehicle 102 successfully unlocks when the authentic key fob 104 is in the proximity of the vehicle 102.
[006] However, there exists a case where the LF signal 106 originating from the
vehicle 102 might get corrupted or the LF communication from the vehicle 102 might get interrupted due to various undesirable and unknown environmental conditions around the vehicle 102. The LF signal 106 may get degraded/corrupted in such noisy locations, where environmental interferences may occur due to various factors such as, but not limited to, proximity of an industrial equipment operating in the same frequency band near the vehicle 102; unbalancing of underground or overhead three phase electric

supply which may create electric noise; presence of battery chargers (DC-DC Power supplies) etc. The presence of any or all of the aforementioned factors might result in corruption of LF signal transmission from the vehicle 102 (i.e., absence of LF wake-up/challenge signal 106). Due to which the user may not be able to unlock the vehicle 102, as the key fob 104 may not wake up and transmission of RF response signal might not occur as a part of LF-RF authentication process, resulting in failure of LF-RF based keyless authentication process.
[007] There is no efficient and convenient solution for preventing the LF-RF
based authentication failure incurred due to the noisy surroundings. Thus, there exists a need for further improvements in the technology to solve above-mentioned problems and overcome the disadvantages or difficulties of existing keyless access systems and/or techniques associated therewith.
[008] The information disclosed in this background of the disclosure section is
only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
SUMMARY
[009] One or more shortcomings discussed above are overcome, and additional
advantages are provided by the present disclosure. The present disclosure provides a solution to the above-identified problems by providing a control strategy to overcome the failure of LF-RF based authentication process due to various undesirable environmental conditions. The proposed techniques counter the LF based authentication failure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the disclosure.
[0010] An objective of the present disclosure is to provide a resilient low frequency- radio frequency (LF-RF) based vehicle keyless access system.

[0011] Another objective of the present disclosure is to detect a failure in LF-RF based authentication process due to various undesirable environmental conditions.
[0012] Yet another objective of the present disclosure is to find an easy way out to start the vehicle without wasting time in contacting a service engineer/station to replace/bypass security mechanisms of vehicles.
[0013] The above stated objects as well as other objects, features, and advantages of the present disclosure will become clear to those skilled in the art upon review of the following description, the attached drawings, and the appended claims.
[0014] According to an aspect of present disclosure, methods and apparatus/systems are provided for overcoming low frequency-radio frequency (LF-RF) based authentication failure in a vehicle.
[0015] In one non-limiting embodiment of the present disclosure, a method of overcoming low frequency-radio frequency (LF-RF) based authentication failures in a vehicle is disclosed. The method may comprise receiving a radio frequency (RF) signal from an authorized remote device upon failure of LF-RF based authentication and in response to receiving the RF signal from the authorized remote device, temporarily unlocking the vehicle and turning ON an engine of the vehicle. The method may further comprise in response to turning ON the vehicle engine, displacing the vehicle for a minimal predefined threshold distance and locking the vehicle and turning OFF the vehicle engine to bring the vehicle in a standstill position after being displaced by the minimal predefined threshold distance. The method may further comprise in response to determining that the vehicle has been displaced by the minimal predefined threshold distance, performing LF-RF based authentication; and propelling the vehicle to enter in ready to go condition upon successful LF-RF based authentication.
[0016] In another non-limiting embodiment, the present disclosure discloses an apparatus for overcoming low frequency-radio frequency (LF-RF) based authentication failures for a vehicle. The apparatus may comprise a memory, at least one transceiver, and at least one processor communicatively coupled to the memory and the transceiver.

The at least one processor may be configured to receive a radio frequency (RF) signal from an authorized remote device upon failure of LF-RF based authentication and in response to receiving the RF signal from the authorized remote device, temporarily unlock the vehicle and turn ON an engine of the vehicle. In response to turning ON the vehicle engine, at least one processor may be configured to displace the vehicle for a minimal predefined threshold distance; and lock the vehicle and turn OFF the vehicle engine to bring the vehicle in a standstill position after being displaced by the minimal predefined threshold distance. In response to determining that the vehicle has been displaced by the minimal predefined threshold distance, the at least one processor may be configured to perform LF-RF based authentication and propel the vehicle to enter in ready to go condition upon successful LF-RF based authentication.
[0017] In another non-limiting embodiment, the present disclosure discloses a method of operating a remote device for overcoming low frequency-radio frequency (LF-RF) based authentication failures in a vehicle. The method may comprise receiving an input from a user upon failure of LF-RF based authentication and in response to receiving the user input, transmitting a radio frequency (RF) signal to the vehicle for displacing the vehicle for a minimal predefined threshold distance. The method may further comprise receiving an LF wake-up signal from the vehicle after being displaced by the minimal predefined threshold distance and upon receiving the LF wake-up signal, performing LF-RF based authentication for propelling the vehicle to enter in ready to go condition.
[0018] In another non-limiting embodiment, the present disclosure discloses a remote device for overcoming low frequency-radio frequency (LF-RF) based authentication failures in a vehicle. The remote device may comprise a memory, at least one transceiver, and at least one processor communicatively coupled to the memory and the transceiver. The at least one processor may be configured to receive an input from a user upon failure of LF-RF based authentication and in response to receiving the user input, transmit a radio frequency (RF) signal to the vehicle for displacing the vehicle for a minimal predefined threshold distance. The at least one processor may be further configured to receive an LF wake-up signal from the vehicle after being displaced by the minimal predefined threshold distance; and upon receiving the LF wake-up signal,

perform LF-RF based authentication for propelling the vehicle to enter in ready to go condition.
[0019] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BREIF DESCRIPTION OF DRAWINGS
[0020] Further aspects and advantages of the present disclosure will be readily understood from the following detailed description with reference to the accompanying drawings. Reference numerals have been used to refer to identical or functionally similar elements. The figures together with a detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages, in accordance with the present disclosure wherein:
[0021] Figure 1 illustrates an exemplary environment 100 for illustrating the working of a conventional passive keyless access system or PEPS system, in accordance with some embodiments of the present disclosure.
[001] Figure 2 shows an exemplary image 200 of a key fob used in the passive
keyless access system as illustrated in Figure 1, in accordance with some embodiments of the present disclosure.
[002] Figure 3 illustrates an exemplary environment 300 where the proposed
techniques are implemented in the passive keyless access system, in accordance with some embodiments of the present disclosure.
[003] Figure 4 illustrates a block diagram 400 of low frequency-radio frequency
(LF-RF) based passive keyless access system for overcoming low frequency-radio frequency (LF-RF) based authentication failures in a vehicle, in accordance with some

embodiments of the present disclosure.
[004] Figure 5 is a flow diagram representing exemplary method 500 of
overcoming low frequency-radio frequency (LF-RF) based authentication failures in a vehicle, in accordance with some embodiments of the present disclosure.
[005] Figure 6 is a flow diagram representing exemplary method 600 of
operating a remote device for overcoming low frequency-radio frequency (LF-RF) based authentication failures in a vehicle, in accordance with some embodiments of the present disclosure.
[006] It should be appreciated by those skilled in the art that any block diagrams
herein represent conceptual views of illustrative systems embodying the principles of the present subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in computer readable medium and executed by a computer or processor, whether or not such computer or processor is explicitly shown.
DETAILED DESCRIPTION
[007] Referring now to drawings, there is shown an illustrative embodiment of
the disclosure “a resilient low frequency-radio frequency based passive keyless access system and method thereof”. It is understood that the disclosure is susceptible to various modifications and alternative forms; specific embodiments thereof have been shown by way of example in the drawings and will be described in detail below. It will be appreciated as the description proceeds that the disclosure may be realized in different embodiments.
[008] The terms “comprises”, “comprising”, “includes” or any other variations
thereof, are intended to cover a non-exclusive inclusions, such that a setup, device that comprises a list of components that does not include only those components but may include other components not expressly listed or inherent to such setup or device. In

other words, one or more elements in a system or apparatus proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus or device. It could be noted with respect to the present disclosure that the terms like “resilient low frequency-radio frequency based passive keyless access system”, “The system” refers to the same system which is used in the present disclosure.
[009] In the present document, the word “exemplary” is used herein to mean
“serving as an example, instance, or illustration.” Any embodiment or implementation of the present subject matter described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.
[0010] While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.
[0011] The term like “key fob”, “remote device”, and “remote key fob” may be used interchangeably throughout the description. Further, the terms like “passive keyless access system”, “keyless access system”, “keyless entry and start system”, and “Passive Entry Passive Start (PEPS) system” may be used interchangeably throughout the description. Further, the terms like “LF signal”, “LF wakeup signal”, and “LF challenge” may be used interchangeably throughout the description. Further, the terms like “RF signal” and “RF frame sequence” may be used interchangeably throughout the description.
[0012] In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments

may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.
[0013] According to an aspect, the present disclosure provides techniques to overcome the failure of LF-RF based authentication process in remote passive keyless entry systems.
[0014] A Passive Entry Passive Start (PEPS) system or passive keyless entry system as illustrated in Figure 1 allows granting keyless access of a vehicle 102 to an authorized user by incorporating LF-RF based authentication mechanism between the vehicle 102 and a remote key fob 104. The PEPS system may be used for two wheelers, four-wheelers, or multi-wheelers. The brief working of a PEPS system used in four wheelers is discussed as follows. If an LF signal originated from the four-wheeler is detected by the key fob 104 while the key fob 104 is in the close vicinity of the vehicle 102, the key fob 104 wakes up from the sleep mode. If the received signal is successfully decoded, the key fob 104 sends an encrypted RF response signal on a RF channel using a secret key stored in it. The RF frequency range may be selected to save battery power of the key fob 104. If the vehicle 102 verifies the RF response signal from the key fob 104, it unlocks the doors. So, the vehicle 102 successfully unlocks when the authentic key fob 104 is in the proximity of the vehicle 102. The PEPS system when used in two wheelers, allows the access of the vehicle 102 by keyless LF-RF based authentication when the key fob 104 is in the vehicle proximity followed by unlocking of electronic steering column lock by short press of a push button switch on steering column of the two-wheeler vehicle.
[0015] Referring now to Figure 2 which shows an exemplary image 200 of the key fob 104 used in the PEPS system illustrated in Figure 1. The key fob 104 is depicted as possessing one push button switch referred as “vehicle finder button” 202. The vehicle finder button 202 may be used by an authentic user of the vehicle 102 for determining a location of the vehicle 102 (four-wheeler/two-wheeler/multi-wheeler) from a significant distance by transmission of ultra-high frequency or RF signal from the key fob 104. The vehicle 102 responds to the key fob button press in a stipulated

pattern (signed off by tier 1 supplier and vehicle manufacturer), by way of providing some indication / evidence of presence of the vehicle 102, which includes, but not limited to, blinking of front and/or back flashers in a predefined stipulated pattern, upon successful vehicle finder command validation. It should be noted here that the authentication process for vehicle lock and unlock is accomplished by the mere presence of key fob 104, without the user intervention in a typical PEPS system.
[0016] In one non-limiting embodiment, the key fob 104 may comprise various other command buttons such as lock, unlock, etc. The key fob 104 may be used to lock/unlock and locate any vehicle located within proximity of the key fob 104. Additional commands can be created by pressing multiple command buttons, by pressing a command button multiple times, or by pressing the command button for a prescribed time duration. The remote key-fob 104 may comprise an inbuilt LED to provide various indications for low battery indication, lock status indication, or any other similar and/or related purposes.
[0017] Referring now to Figure 3, which illustrates an exemplary environment 300 where the proposed techniques of overcoming low frequency-radio frequency (LF-RF) based authentication failures are implemented in the keyless access system or the PEPS system. The PEPS system shown in Figure 3 works in similar fashion as that of the system depicted in Figure 1, with at least one upgrade of depicting two types of RF response signals. The PEPS system comprises at least the vehicle 102 and the key fob 104. However, the present disclosure is not limited thereto, and the PEPS system may comprise other elements as well.
[0018] Now Figure 3 is explained in conjunction with Figure 4 which shows a block diagram illustrating the PEPS system 400 for overcoming the failure of LF-RF based authentication process due to various undesirable environmental conditions, in accordance with some embodiments of the present disclosure.
[0019] According to an embodiment of the present disclosure, the PEPS system 400 may comprise a vehicle security sub-system 410 and a key fob system 420. The vehicle security sub-system 410 may be a part of the vehicle 102 and may comprise at

least one memory 402, at least one transceiver 404, and at least one processor 406. The key fob system 420 may be same as the key fob 104 or may be part of the key fob 104 and may comprise at least one memory 412, at least one transceiver 414, at least one processor 416, and at least one command button 418. The transceivers 404, 414 may be used for transmitting and receiving signals and other information between the vehicle 102 and key fob 104. The transceivers 404, 414 may comprise antennas for transmitting and receiving the signals. In one embodiment, the vehicle security sub-system 410 and the key fob 420 may also comprise respective I/O interfaces that may include a variety of software and hardware interfaces, for example, a web interface, a graphical user interface, input device, output device and the like. The I/O interfaces may allow the vehicle security sub-system 410 to interact with the key fob 420 directly or through other devices.
[0020] The memories 402, 412 may be communicatively coupled with the processors 406, 416 respectively. The memories 402, 412 may store necessary commands needed for execution of various operation of the PEPS system 400. A memory may include a Random-Access Memory (RAM) unit and/or a non-volatile memory unit such as a Read Only Memory (ROM), optical disc drive, magnetic disc drive, flash memory, Electrically Erasable Read Only Memory (EEPROM), a memory space on a server or cloud and so forth. For the sake of illustration, it is assumed here that the memory is a non-volatile memory. Examples of the processors may include, but not restricted to, a general-purpose processor, a Field Programmable Gate Array (FPGA), an Application Specific Integrated Circuit (ASIC), a Digital Signal Processor (DSP), microprocessors, microcomputers, micro-controllers, digital signal processors, central processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions.
[0021] In one non-limiting embodiment of the present disclosure, the memory 402 may be referred as a storage unit, the processor 406 may be referred as a processing unit, the transceiver 404 may be referred as transmitting and/or receiving unit. Further, the memory 412 may be referred as a storage unit, the processor 416 may be referred as a processing unit, the transceiver 414 may be referred as transmitting and/or receiving unit. In one embodiment, the command button 418 may imitate or act as the vehicle

finder button 202.
[0022] An authentic user possessing the key fob 104 may press the command button 418 in a stipulated pattern for finding the location of the vehicle 102. Upon successful pressing the button 418, the processor 416 in conjunction with the transceiver 414 may generate and broadcast/transmit a vehicle finder command. The vehicle finder command may comprise a RF signal or RF frame sequence which contains a specific bit sequence. In the preferred embodiment, one way to generate the vehicle finder command is single pressing the command button 418 for a stipulated duration. However, any specific pattern of button press may be used for generating the vehicle finder command.
[0023] The vehicle finder command may be used to detect the presence of the vehicle 102 from the key fob 104 within an RF range. The vehicle transceiver 404 may detect the vehicle finder command and may send an alert, including, but not limited to, blinking the front and/or back flashers in a predefined pattern. When the user moves in the proximity of the vehicle 102, i.e., within LF range, the vehicle transceiver 404 in conjunction with the vehicle processor 406 may detect the presence of the key fob 104. When the key fob 104 is within the LF range, the LF wakeup signal or the LF challenge signal 106 emanating from the vehicle transceiver 404 reaches to the key fob transceiver 414 and subsequently the key fob processor 416 authenticates the LF challenge signal 106 by transmitting a first encrypted RF response signal 108 from the key fob transceiver 414 to the vehicle transceiver 404. This successfully completes the LF-RF authentication process.
[0024] In one exemplary non-limiting embodiment, the LF range may be considered as approximately 2 meters and the RF range may be considered as approximately 50 meters. The RF range is selected so as to save the battery power of the key fob 104. The vehicle security sub-system 410 may continuously transmit the LF signals with prescribed time intervals. Upon successful LF-RF authentication process, the user may short press a touch button switch (not shown) which might be placed on the steering / handle of the vehicle 102, to start the vehicle 102 and the vehicle may enter into ready to go condition. The aforementioned processes take place where there is

no LF signal corruption in the ambient environment. In one non-limiting exemplary embodiment, the LF ranges from 120 KHz to 135 KHz and the RF ranges from 315 MHz to 433 MHz.
[0025] As discussed previously, the LF signal 106 originating from the vehicle 102 might get corrupted or the LF communication from the vehicle 102 might get interrupted due to various undesirable and unknown environmental interferences such as, but not limited to, presence of electrical/magnetic/electromagnetic noises around the vehicle 102. The environmental interferences might occur due to various factors such as, but not limited to, proximity of an industrial equipment operating in the same frequency band near the vehicle 102; unbalancing of underground or overhead three phase electric supply which may create electric noise; presence of battery chargers (DC-DC Power supplies) etc. The presence of at least one of the aforementioned factors might result in corruption of LF signal transmission from the vehicle 102 (i.e., absence of LF wake-up/challenge signal). Due to which user may not be able to unlock the vehicle 102, as the key fob 104 does not wake up and transmission of RF response signal 108 might not occur as a part of LF-RF authentication process, resulting in failure of LF-RF based keyless authentication process.
[0026] Due to the various factors as discussed above, the LF signal 106 emanating from the vehicle transceiver 404 may get corrupted before reaching to the key fob transceiver 414. The user has already detected the location of the vehicle 102 by the press of vehicle finder command button 418, however the user comes to know about the LF authentication failure upon reaching in the vicinity of the vehicle 102 when he/she tries to unlock the vehicle 102 by the short press of a push button (in case of two wheelers) and not being able to unlock the steering lock and thereby start the vehicle 102 or to open the door (in case of four wheelers) and succeed due to the prevailing reasons. So, the user might not get success in unlocking the vehicle 102.
[0027] In one non-limiting embodiment, upon detecting the LF authentication failure, the user performs a predefined button press operation in a stipulated manner on the key fob 104 to generate a RF frame sequence 110 or second RF response signal. In one embodiment, the user may double press the vehicle finder button 418 within a

stipulated time interval to generate the RF frame sequence 110. In response to receiving the command from the user, the key fob processor 416 may generate and transmit the second RF response signal 110 to the vehicle processor 406 via the transceiver 414. The vehicle transceiver 404 may receive the second RF response signal 110 and the vehicle processor 406 may perform following operations upon receiving the second RF signal 110.
[0028] In one non-limiting embodiment, the processor 406 may process the received second RF signal 110 to determine a Received Signal Strength Indicator (RSSI) value associated with the second RF signal 110 and then compare the determined RSSI value with a predefined threshold value. The at least one processor 406 may allow subsequent operations to be performed only when the RSSI value is greater than the predefined threshold value i.e. the user is in close vicinity of the vehicle 102.
[0029] The vehicle processor 406 may determine whether the second RF signal 110 is received from an authorized key fob. In response to determining that the second RF signal 110 is received from the authorized key fob, the vehicle processor 406 may temporarily unlock the vehicle 102 and turn ON an engine of the vehicle 102. It is expected that the vehicle 102 will be displaced by some predefined threshold distance by the user after starting the vehicle engine.
[0030] The vehicle processor 406 may then obtain the data related to the distance moved from an instrument cluster Electronic Control Unit (ECU) / engine ECU over a Controller Area Network (CAN) interface and determine whether the vehicle 102 has been displaced by a distance greater than a predefined threshold distance. In response to determining that the vehicle 102 has been displaced by the predefined threshold distance, the vehicle processor 406 may lock the vehicle and turn OFF the vehicle engine to bring the vehicle 102 in a standstill position and again attempt the conventional LF-RF based authentication process. It is assumed here that after moving the vehicle by the predefined distance, the vehicle gets away from the noisy environment. Upon being successful in the LF-RF authentication process, the vehicle processor 406 may propel the vehicle to enter in ready to go condition.

[0031] In response to determining that LF-RF based authentication is unsuccessful, the vehicle processor 406 may take necessary safety measures such as, but not limited to, switching OFF the engine, locking the vehicle 102, and bringing the vehicle 102 in a standstill position. In case of unsuccessful LF-RF based authentication, the vehicle processor 406 may again start waiting for reception of RF response signal 110 from an authorized remote device.
[0032] In one non-limiting embodiment, in response to determining that the second RF response signal 110 is received from the authorized key fob, the vehicle processor 406 may temporarily unlock the vehicle 102 and turn ON the vehicle engine for a predefined time period. It is expected that the vehicle 102 will be displaced by the predefined threshold distance during the predefined time period. In response to determining that the vehicle 102 is not displaced by the predefined threshold distance during the predefined time period, the vehicle processor 406 may take necessary safety measures such as, but not limited to, switching OFF the engine, locking the vehicle 102, and bringing the vehicle 102 in the standstill position.
[0033] In this way the resilient LF-RF based passive keyless access system provides an easier, safer, efficient, and convenient way of overcoming the LF-RF authentication failure compared to the conventional keyless access systems.
[0034] Figure 5 depicts a flowchart illustrating a method 500 for providing low frequency- radio frequency (LF-RF) based authentications in a passive keyless access system. In particular, Figure 5 illustrates a method for overcoming low frequency-radio frequency (LF-RF) based authentication failures in a vehicle 102, in particular the LF authentication failure process, due to various undesirable environmental conditions, in accordance with some embodiments of the present disclosure.
[0035] The method starts when the user detects the LF-RF based authentication failure upon reaching in the vicinity of the vehicle 102, while the user is trying to unlock the vehicle 102 by the short press of a push button (in case of two wheelers) on the steering column or opening of the door (in case of four wheelers). Upon detecting the

LF-RF authentication failure, the user performs a predefined button press operation on the key fob 104 within a predefined time interval to generate a RF signal 110.
[0036] The method starts at block 502, where the vehicle processor 406 in conjunction with the vehicle transceiver 404 receives the RF signal 110 from the key fob 104. In a non-limiting embodiment, upon receiving the RF signal 110, the vehicle processor 406 may determine whether the RF signal 110 is received from an authorized key fob or not. The vehicle processor 406 may store data corresponding to predetermined stipulated RF signal 110 for its detection, vehicle identification, and subsequent authentication by the vehicle 102.
[0037] At block 504, the vehicle processor 406 may process the received RF signal 110 to determine the Received Signal Strength Indicator (RSSI) value associated with the RF signal 110.
[0038] At block 506, the vehicle processor 406 may compare the determined RSSI value with a predefined threshold value. If it is found that the RSSI value is greater than the predefined threshold value (block 508) which means that the user is in close vicinity of the vehicle 102, the method proceeds at block 510. Alternatively, if it is found that the RSSI value is less than or equal to the predefined threshold value, the method retrieves back to the block 502 and awaits to receive an RF signal 110 from the authorized key fob.
[0039] At block 510, upon determining that the RSSI value of the received RF signal 110 is greater than the predefined threshold value, the vehicle processor 406 may temporarily unlock the vehicle 102 and turn ON the vehicle engine.
[0040] At block 512, the vehicle user may prompt the processor 406 to displace the vehicle 102 for a predefined minimal threshold distance.
[0041] At block 514, the vehicle processor 406 may lock the vehicle and turn OFF the vehicle engine to bring the vehicle in a standstill position after being displaced by the predefined minimal threshold distance.

[0042] At block 516, in response to determining that the vehicle has been displaced by the minimal predefined threshold distance, the vehicle processor 406 may perform the LF-RF based authentication process as described above.
[0043] At block 518, the vehicle processor 406 may determine whether the LF-RF based authentication is successful. If the LF-RF based authentication is successful, the method proceeds at block 520. Else the method retrieves back to the block 502 awaiting to receive an RF signal 110 from the authorized key fob.
[0044] At block 520, upon determining that the LF-RF authentication process is successful, the vehicle processor 406 may propel the vehicle 102 to enter in ready to go condition.
[0045] In one non-limiting embodiment of the present disclosure, performing the LF-RF based authentication may comprise continuously broadcasting an LF wake-up signal 106 and receiving an encrypted RF response signal 108 from the authorized key fob 104, where the received encrypted RF response signal 108 corresponds to the broadcasted LF wake-up signal 106 and comprises a secret key. Performing the LF-RF based authentication may comprise verifying the RF response signal 108 using the secret key and unlocking the vehicle 102 upon successful verification of the RF response signal 108.
[0046] It has been shown that above method steps are being performed by a vehicle processor 406 in conjunction with the transceiver 404 and the memory 402. However, it may be noted that some or all of the above-mentioned method steps may be performed by dedicated hardware units such as, but not limited to, dedicated PEPS ECU, engine ECU etc.
[0047] Figure 6 depicts a flowchart illustrating a method 600 of operating a remote key fob 104 for overcoming low frequency-radio frequency (LF-RF) based authentication failures in a vehicle 102. As illustrated in Figure 6, the method 600 includes one or more blocks illustrating a method of operating the remote key fob 104

for overcoming low frequency-radio frequency (LF-RF) based authentication failures.
[0048] The method starts when the user detects the LF-RF based authentication failure upon reaching in the vicinity of the vehicle 102, while the user is trying to unlock the vehicle 102 by the short press of a push button (in case of two wheelers) on the steering column or opening of the door (in case of four wheelers). Upon detecting the LF-RF authentication failure, the user performs a predefined button press operation on the key fob 104 within a predefined time interval to generate a RF signal 110.
[0049] The method starts at block 602, where the key fob processor 416 in conjunction with the key fob transceiver 414 receives an input from a user.
[0050] At block 604, the key fob processor 416 in conjunction with the key fob transceiver 414 may transmit a RF signal 110 to the vehicle 102 allowing the user to displace the vehicle for a minimal predefined threshold distance.
[0051] At block 606, the key fob processor 416 in conjunction with the key fob transceiver 414 may receive an LF wake-up signal 106 from the vehicle 102 after being displaced by the minimal predefined threshold distance.
[0052] At block 606, the key fob processor 416 upon receiving the LF wake-up signal may perform the LF-RF based authentication for propelling the vehicle 102 to enter in ready to go condition.
[0053] The order in which the various operations of the methods 500, 600 are described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the spirit and scope of the subject matter described herein. Furthermore, the methods can be implemented in any suitable hardware, software, firmware, or combination thereof.
[0054] The various operations of the methods 500, 600 described above may be

performed by any suitable means capable of performing the corresponding functions. The means may include various hardware and/or software component(s) and/or module(s). Generally, where there are operations illustrated in Figures, those operations may have corresponding counterpart means-plus-function components.
[0055] It may be noted here that the subject matter of some or all embodiments described with reference to Figures 1-4 may be relevant for the methods 500, 600 and the same is not repeated for the same of brevity.
[0056] In a non-limiting embodiment of the present disclosure, one or more non-transitory computer-readable media may be utilized for implementing the embodiments consistent with the present disclosure. A computer-readable media refers to any type of physical memory (such as the memory 402, 412) on which information or data readable by a processor may be stored. Thus, a computer-readable media may store one or more instructions for execution by the at least one processor 406, 416, including instructions for causing the at least one processor 406, 416 to perform steps or stages consistent with the embodiments described herein. Thus, certain aspects may comprise a computer program product for performing the operations presented herein.
[0057] Various components, modules, or units are described in this disclosure to emphasize functional aspects of devices configured to perform the disclosed techniques, but do not necessarily require realization by different hardware units. Rather, as described above, various units may be combined in a hardware unit or provided by a collection of interoperative hardware units, including one or more processors as described above, in conjunction with suitable software and/or firmware.
[0058] Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based here on. Accordingly, the embodiments of the present invention are intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the appended claims.

WE CLAIM:
1. A method (500) of overcoming low frequency-radio frequency (LF-RF) based
authentication failures in a vehicle (102), the method comprising:
receiving (502) a radio frequency (RF) signal from an authorized remote device (104) upon failure of LF-RF based authentication;
in response to receiving the RF signal from the authorized remote device, temporarily unlocking (510) the vehicle and turning ON an engine of the vehicle;
in response to turning ON the vehicle engine, displacing (512) the vehicle for a minimal predefined threshold distance;
locking the vehicle and turning OFF the vehicle engine (514) to bring the vehicle in a standstill position after being displaced by the minimal predefined threshold distance;
in response to determining that the vehicle has been displaced by the minimal predefined threshold distance, performing (516) LF-RF based authentication; and
propelling (520) the vehicle to enter in ready to go condition upon successful LF-RF based authentication.
2. The method as claimed in claim 1, wherein temporarily unlocking the vehicle and
turning ON the vehicle engine comprises:
processing the received RF signal to determine a Received Signal Strength
Indicator (RSSI) value associated with the received RF signal;
comparing the determined RSSI value with a predefined threshold value; and temporarily unlocking the vehicle and turning ON the vehicle engine in response to
determining that the determined RSSI value is greater than the predefined threshold
value.
3. The method as claimed in claim 1, wherein the remote device is a remote key fob, and wherein the LF-RF based authentication failure occurs due to presence of at least one of electrical noise, magnetic noise, and electromagnetic noise around the vehicle.
4. The method as claimed in claim 1, wherein performing the LF-RF based authentication comprises:
continuously broadcasting an LF wake-up signal;

receiving an encrypted RF response signal from the authorized remote device, wherein the received encrypted RF response signal corresponds to the broadcasted LF wake-up signal and comprises a secret key; and
verifying the RF response signal using the secret key and unlocking the vehicle upon successful verification of the RF response signal.
5. An apparatus (410) for overcoming low frequency-radio frequency (LF-RF) based
authentication failures for a vehicle (102), the apparatus comprising:
a memory (402);
at least one transceiver (404); and
at least one processor (406) communicatively coupled to the memory and the transceiver, wherein the at least one processor is configured to:
receive a radio frequency (RF) signal from an authorized remote device (104) upon failure of LF-RF based authentication;
in response to receiving the RF signal from the authorized remote device, temporarily unlock the vehicle and turn ON an engine of the vehicle;
in response to turning ON the vehicle engine, displace the vehicle for a minimal predefined threshold distance;
lock the vehicle and turn OFF the vehicle engine to bring the vehicle in a standstill position after being displaced by the minimal predefined threshold distance;
in response to determining that the vehicle has been displaced by the minimal predefined threshold distance, perform LF-RF based authentication; and
propel the vehicle to enter in ready to go condition upon successful LF-RF based authentication.
6. The apparatus as claimed in claim 5, wherein for temporarily unlocking the vehicle
and turning ON the vehicle engine, the at least one processor is configured to:
process the received RF signal to determine a Received Signal Strength Indicator
(RSSI) value associated with the received RF signal;
compare the determined RSSI value with a predefined threshold value; and temporarily unlock the vehicle and turn ON the vehicle engine in response to
determining that the determined RSSI value is greater than the predefined threshold

value.
7. The apparatus as claimed in claim 5, wherein the remote device is a remote key fob, and wherein the LF-RF based authentication failure occurs due to presence of at least one of electrical noise, magnetic noise, and electromagnetic noise around the vehicle.
8. The apparatus as claimed in claim 5, wherein for performing the LF-RF based authentication, the at least one processor is configured to:
continuously broadcast an LF wake-up signal;
receive an encrypted RF response signal from the authorized remote device, wherein the received encrypted RF response signal corresponds to the broadcasted LF wake-up signal and comprises a secret key; and
verify the RF response signal using the secret key and unlock the vehicle upon successful verification of the RF response signal.
9. A method (600) of operating a remote device (104, 420) for overcoming low
frequency-radio frequency (LF-RF) based authentication failures in a vehicle (102), the
method comprising:
receiving (602) an input from a user upon failure of LF-RF based authentication;
in response to receiving the user input, transmitting (604) a radio frequency (RF) signal to the vehicle for displacing the vehicle for a minimal predefined threshold distance;
receiving (606) an LF wake-up signal from the vehicle after being displaced by the minimal predefined threshold distance; and
upon receiving the LF wake-up signal, performing (608) LF-RF based authentication for propelling the vehicle to enter in ready to go condition.
10. A remote device (420) for overcoming low frequency-radio frequency (LF-RF)
based authentication failures in a vehicle (102), the remote device comprising:
a memory (412);
at least one transceiver (414); and
at least one processor (416) communicatively coupled to the memory and the transceiver, wherein the at least one processor is configured to:

receive an input from a user upon failure of LF-RF based authentication;
in response to receiving the user input, transmit a radio frequency (RF) signal to the vehicle for displacing the vehicle for a minimal predefined threshold distance;
receive an LF wake-up signal from the vehicle after being displaced by the minimal predefined threshold distance; and
upon receiving the LF wake-up signal, perform LF-RF based authentication for propelling the vehicle to enter in ready to go condition.