Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
  • H04K3/00—Jamming of communication; Counter-measures
  • H04K3/80—Jamming or countermeasure characterized by its function
  • H04K3/88—Jamming or countermeasure characterized by its function related to allowing or preventing alarm transmission
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R25/00—Fittings or systems for preventing or indicating unauthorised use or theft of vehicles
  • B60R25/20—Means to switch the anti-theft system on or off
  • B60R25/2072—Means to switch the anti-theft system on or off with means for preventing jamming or interference of a remote switch control signal
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
  • H04K3/00—Jamming of communication; Counter-measures
  • H04K3/20—Countermeasures against jamming
  • H04K3/22—Countermeasures against jamming including jamming detection and monitoring
  • H04K3/222—Countermeasures against jamming including jamming detection and monitoring wherein jamming detection includes detecting the absence or impossibility of intelligible communication on at least one channel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R25/00—Fittings or systems for preventing or indicating unauthorised use or theft of vehicles
  • B60R25/10—Fittings or systems for preventing or indicating unauthorised use or theft of vehicles actuating a signalling device
  • B60R2025/1013—Alarm systems characterised by the type of warning signal, e.g. visual, audible
  • B60R2025/1016—Remote signals alerting owner or authorities, e.g. radio signals
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R2325/00—Indexing scheme relating to vehicle anti-theft devices
  • B60R2325/20—Communication devices for vehicle anti-theft devices
  • B60R2325/205—Mobile phones
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
  • H04K2203/00—Jamming of communication; Countermeasures
  • H04K2203/10—Jamming or countermeasure used for a particular application
  • H04K2203/16—Jamming or countermeasure used for a particular application for telephony
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
  • H04K2203/00—Jamming of communication; Countermeasures
  • H04K2203/10—Jamming or countermeasure used for a particular application
  • H04K2203/18—Jamming or countermeasure used for a particular application for wireless local area networks or WLAN
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
  • H04K2203/00—Jamming of communication; Countermeasures
  • H04K2203/10—Jamming or countermeasure used for a particular application
  • H04K2203/22—Jamming or countermeasure used for a particular application for communication related to vehicles

Definitions

• the field of the invention is that of radio communication systems enabling radio communication devices to connect to radiocommunication networks.
• Radiocommunication devices are any devices or means capable of exchanging signals using a radio communication system, for example installed in machines (M2M market, for "Machine to Machine”) or vehicles (automotive market).
• M2M market for "Machine to Machine”
• vehicles automotive market
• the field of application of the invention covers any cellular radio technology (GSM, 3G, 4G, DECT, CDMA, Wi-Max %), point-to-point radiocommunication (Wifi, Bluetooth, Zigbee %) or analog radio communication.
• the invention relates to a scrambling detection technique of a radio communication network by a radio communication circuit capable of connecting to this network by synchronizing on a radio communication channel.
• radiocommunication circuit is an electronic radiocommunication module
• the company WAVECOM has indeed for several years proposed an approach consisting in grouping in a single module (called electronic radio communication module), all or at least most of the functions of a digital radiocommunication device.
• a module is in the form of a single housing, preferably shielded, that the device manufacturers can implement directly, without having to take into account a multitude of components.
• This module (sometimes also called “macro component”) is indeed formed of a grouping of several components on a substrate, so as to be implanted in the form of a single element. It includes the essential components (including a processor, memories, and software) necessary for the operation of a radiocommunication device using radio frequencies.
• the radiocommunication circuit is not a radiocommunication module in the aforementioned sense but a printed circuit included in a radiocommunication device and on which are directly implanted a set of electronic components whose purpose is to provide the various radiocommunication functions necessary, from the reception of an RF signal until the generation of an audible signal (in the case of a radio telephone), and vice versa.
• radiocommunication circuits communicates modules
• jam detection capabilities to their customers.
• the present technique of detection of interference by these radiocommunication circuits consists in carrying out a complete diagnosis of the radio environment and, following the result of this diagnosis, provide a status of the type: "the network is scrambled” or "the network n”. is scrambled.
• Such a device comprises: A radio communication circuit (for example a GSM module), making it possible to communicate with a flight management server to reassemble / retrieve information;
• a radio communication circuit for example a GSM module
• a GPS module allowing to have the position of the vehicle; and "a security module, to immobilize the vehicle (activation of a contact cut), to trigger an alarm or to perform any other action to limit access or use of the vehicle by the potential thief.
• the recovery device can be rendered totally ineffective by the mere presence of a jammer that can be plugged into the cigarette lighter socket. Indeed, if the device has not detected the intrusion and theft of the car, no longer receiving message through the radio network, it can no longer be warned by the flight management server that the car is stolen and therefore can not activate the contact cut or the alarm, and is therefore completely ineffective. If the radio circuit supports the jam detection capability, the provision by the radio communication circuit of the information "the radio network is scrambled" may take several tens of seconds.
• the radiocommunication circuit launches a complete diagnosis of the radio environment and at the end of this diagnosis provides its conclusion: "the radiocommunication network is scrambled Or "the radio network is not scrambled".
• This diagnosis can take 40 seconds in the case of a GSM network, for example. All the while, the thief can enter the car and start it. However, once the car is started, the device, for obvious reasons of road safety, is not legally allowed to engage the contact cut. On the other hand, being scrambled, the radio circuit can no longer communicate with the flight management server. The thief can therefore drive the car in a discreet location, where he can easily search the stolen car recovery device and disable it.
• JDR jammed condition report
• the DCMN parameter is frozen (for example at 5).
• the MNPL parameter is also fixed, and set by the network operator, for each cell. These two parameters are used for a fine tuning of the scrambling detection algorithms, and their values are set at the factory and should not normally be changed (unless the mobile is installed in a particular environment, the default values can then be changed to be adapted to this particular environment).
• the scrambling detection comprises a single detection phase of complete diagnosis of the radio environment.
• the decision taken at the end of this single detection phase is therefore a final decision.
• the result provided is:
• 2005/112321 A1 is not optimal because it results from a compromise between on the one hand the reliability of the detection of jamming and on the other hand the speed of decision:
• an objective is to provide a scrambling detection technique of a radio communication network which, for a given number N of "non-synchronizable" radio channels on which made the scrambling detection decision (this number N is therefore associated with a 100% interference probability), accelerate decision-making in case of interference detection and authorize the launch of preventive action (s) (s).
• At least one embodiment of the invention also aims to provide such a technique allowing, for the choice of said number N of radiocommunication channels, to overcome the compromise between the reliability of the interference detection and the speed of decision.
• a method for detecting the interference of a radio communication network said method being implemented by a radio communication circuit capable of connecting to said network. network by synchronizing on a radio communication channel, said method comprising: a final detection phase, comprising the following steps: * detection of the verification of the following final condition: there are N radio communication channels on which the radiocommunication circuit can not not synchronize despite detection of a power level normally sufficient to synchronize, with N> 2;
• At least one intermediate detection phase comprising the following steps:
• the general principle of the invention therefore consists in providing at least one intermediate detection phase, making it possible to generate an intermediate scrambling signal with a probability of interference of less than 100%.
• This intermediate scrambling signal makes it possible to trigger at least one intermediate action (also called preventive action because it is performed before the final scrambling signal is generated, with a 100% interference probability).
• at least one intermediate action also called preventive action because it is performed before the final scrambling signal is generated, with a 100% interference probability.
• the invention therefore relies on a completely new and inventive approach of performing multi-phase (instead of only one) scrambling detection using the at least one intermediate condition associated with an intermediate interference signal with a probability of less than 100%.
• said method comprises a first phase of intermediate detection, comprising the following steps:
• said method comprises a second intermediate detection phase, comprising the following steps: detection of the verification of the second intermediate condition: for all or at least a predetermined proportion of the radio communication channels whose frequency is comprised in at least one operating band of the radiocommunication circuit, detecting a power level higher than a determined threshold; if said second intermediate condition is verified, generating a second intermediate scrambling signal with a second probability of interference less than 100%.
• said first and second detection phases can be implemented in a complementary or separate manner.
• said determined threshold is equal to a minimum power level for the synchronization of the radiocommunication circuit.
• said method comprises at least a third phase of intermediate detection, comprising the following steps: detection of verification of the third intermediate condition: there are N 'radiocommunication channels on which said radiocommunication circuit can not be synchronize despite detection of a power level normally sufficient to synchronize, with N ' ⁇ N; if said third intermediate condition is verified, generating a third intermediate scrambling signal with a third probability of interference less than 100%.
• one or more third intermediate detection phases can be carried out, each being associated with a different number N 'and making it possible to generate an interference detection signal with a different probability of interference (this probability being greater the greater the number N 'is large).
• said N 'radio communication channels are included in the last list, received by the radiocommunication circuit, of radiocommunication channels associated with neighboring cells of the last current cell before loss of synchronization.
• the GSM module radiocommunication circuit in the above-mentioned sense
• the GSM module is synchronized to a current cell (via the base station of which it communicates), as well as to a maximum of six neighboring cells (via the base stations from which it does not communicate). It periodically listens to these cells and performs power measurements on up to 32 frequencies, following the recommendations in 3GPP 05.08.
• the "last list" received by the GSM module is the list of these at most six neighboring cells.
• said method comprises: at least a fourth intermediate detection phase, comprising the following steps:
• said N "radio communication channels comprise: said N 'radio communication channels; and - radio communication channels not included in said last list of radio communication channels.
• the radio circuit tries to synchronize not only on the radiocommunication channels of the neighboring cells but also on the radiocommunication channels of other cells.
• said radio circuit executes a client application, and in that said method comprises a step of transmitting to said client application at least one of said intermediate scrambling signals generated by said circuit radiocommunication, so that said client application can take into account to make a decision to trigger at least one intermediate action.
• said method comprises a step of transmitting to a remote device, via said radio network or via another communication network, at least one of said intermediate jamming signals generated by said radiocommunication circuit, so that said remote equipment can take into account to make a decision to trigger at least one intermediate action.
• the decision to trigger said at least one intermediate action may depend on other parameters than the intermediate interference signal or signals.
• at least one particular intermediate action whose triggering decision results from taking into account at least one of said intermediate interference signals, consists in interrupting said method before the execution of the phase (s) of detection not yet performed (s), including said final detection phase. In other words, one can decide, according to predetermined criteria
• the process is interrupted without waiting for the interference to be detected with a probability of 100%. It is recalled that in the prior art technique, there is a single detection phase (at the end of which a jamming signal with a probability of 100% is generated), and it is therefore not possible to interrupt the detection process until the 100% probability is reached.
• said circuit is an electronic radiocommunication module intended to be integrated into a radiocommunication device.
• the invention relates to a computer program product downloadable from a communication network and / or recorded on a computer readable medium and / or executable by a processor, said computer program product comprising instructions program code for executing the steps of the aforementioned method, when said program is executed on a computer.
• the invention relates to a storage medium, possibly completely or partially removable, readable by a computer, storing a set of instructions executable by said computer to implement the above method.
• the invention relates to a radio communication circuit comprising means for detecting the interference of a radio communication network, said radio communication circuit being capable of connecting to said network by synchronizing itself on a radio communication channel, said radio communication circuit comprising: - final decision means, comprising:
• means for detecting the verification of the following final condition there are N radio communication channels on which the radiocommunication circuit can not synchronize despite detection of a power level normally sufficient to synchronize, with N>2; means for generating a final jamming signal with an interference probability equal to 100%, activated if said final condition is verified; at least one intermediate decision means, comprising: means for detecting the verification of at least one intermediate condition;
• the radio communication circuit comprises means for implementing the scrambling detection method as described above (in any one of its various embodiments).
• FIG. 1 shows a known software architecture of a GSM stack supporting the execution capacity of at least one client application
• FIG. 2 shows a particular embodiment of a radiocommunication device according to the invention, comprising a radiocommunication module having a software architecture according to FIG. 1
• FIG. 3 presents a flowchart of an exemplary algorithm according to a particular embodiment of the scrambling detection method according to the invention, executed by the main application (and more precisely in the software block
• FIG. 4 illustrates an exemplary algorithm according to a particular embodiment of the scrambling detection method according to the invention, executed by the client application appearing in FIG. 2.
• the radiocommunication circuit is an electronic radiocommunication module.
• This is for example a module of the family "WISMO” (registered trademark) implementing the concept "Open AT” (registered trademark) of the company WAVECOM (applicant for this patent application). It is clear, however, that the present invention also applies in the case of the aforementioned application variant.
• This software architecture typically comprises a radio communication software stack (in the example of FIG. 1, a GSM stack, or "GSM Stack”) comprising: a radiocommunication interrupt manager 1 ("GSM Stack IT Handler”) , which provides physical link services and synchronizes with the GSM network. It corresponds to the GSM physical layer; a set of tasks 2 specific to the GSM stack (“GSM Stack Tasks L1-L3”), divided into layers (Li a L3), and which provide a control service and logical link (“Logical Link and Control Service”). In the GSM standard, it corresponds to L1 / L2 / L3, RR / LAPD / MM / CCRLC /
• GSM AT Commands Task a set of tasks 3 related to AT commands
• IdIe Task a task 4 called "IdIe Task” or "Background task” which executes when no other task requires the CPU resource.
• This software architecture also comprises at least one client application 5
• this client application 5 is positioned between the set of tasks 3 linked to AT commands and the background task 4.
• the arrow referenced 6 indicates an indicative reaction time axis (from about 1 ms to 1 ms). 'at about 10 ms).
• the arrow referenced 7 indicates a priority level axis (from the bottom-priority task 4, which has the lowest priority, to the radiocommunication interrupt manager 1, which has the highest priority).
• This software architecture can also be broken down into two domains: an interrupt management domain 8, in which is included the radiocommunication interrupt manager 1; and a task management domain 9, in which all the aforementioned tasks are understood (tasks 2 specific to the GSM stack, tasks 3 linked to AT commands, background task 4 and tasks of the client application 5).
• interrupt management domain 8 in which is included the radiocommunication interrupt manager 1
• task management domain 9 in which all the aforementioned tasks are understood (tasks 2 specific to the GSM stack, tasks 3 linked to AT commands, background task 4 and tasks of the client application 5).
• the software architecture comprises a single client application 5. It is however clear that the person skilled in the art can easily transpose this example in the case where the software architecture comprises a GSM stack and several applications. client (each client application comprising a set of client tasks and being positioned, within the GSM stack, between the set of tasks 3 linked to AT commands and the background task 4).
• a main radiocommunication application 42 comprising a block software 421 which manages the radio communication software stack (GSM stack for example) and a software block 422 which allows the implementation of the method of the invention (making it possible to detect the interference of the radiocommunication network); and a client application 45.
• the main radiocommunication application 42 and the client application 45 are for example stored in a read-only memory 47 (ROM for example) and, upon initialization of the radiocommunication module 44, the code instructions of these applications are loaded into a RAM 46 (RAM for example) before being executed by the processor 43.
• ROM read-only memory
• RAM random access memory
• radiocommunication module 44 is connected to a connector 26 of external devices, via I / O interfaces for various uses (GPIOs) 27, Serial interfaces of SPI (Serial Peripheral Interface) type (SPI1, SPI2). 28 and 29, a USB interface 210 and a link carrying interrupts (IT) 211.
• GPIOs General Purposes Interface
• BCCH carrier in the GSM terminology (for "Broadcasting Control CHannel")
• BCCH carrier in the GSM terminology (for "Broadcasting Control CHannel"
• a step E31 it is detected whether the radiocommunication module 44 is synchronized or not. In the case where it is synchronized, go to step E32. In the case where it is not synchronized (but the detected field level on all the radio communication channels is not high enough to allow synchronization), go directly to step E34.
• step E32 it is detected whether the following condition C1 is verified: loss of synchronization on all the synchronized cells while the reception field levels detected on these cells have not decreased.
• the number n of synchronized cells is, for example, such that: 1 ⁇ n ⁇ 7. If this condition C1 is verified, a step E33 of generating a first intermediate scrambling signal Sl with a first probability of lower P1 interference is carried out 100%. Then we go to step E34. Otherwise, we return to step E32.
• the steps E32 and E33 form a first intermediate detection phase.
• step E34 it is detected whether the following condition C2 is satisfied: for all or at least a predetermined proportion of the radiocommunication channels whose frequency (BCCH carrier, in the GSM case) is included in at least one operating band of the radiocommunication circuit, detecting a power level higher than a determined threshold.
• this threshold is equal to -105 dBm, that is to say the minimum power level for the synchronization of the radiocommunication module.
• a step E35 for generating a second intermediate interference signal S2 with a second probability of P2 interference lower than 100% and greater than P1 is carried out. Then we go to a step E36. Otherwise, we return to step E34.
• Steps E34 and E35 form a second phase of intermediate detection.
• step E36 it is detected whether the following condition C3 is satisfied: there are N 'radiocommunication channels, among those associated with the neighboring cells (of the last current cell before loss of synchronization), on which the radiocommunication module can not not synchronize despite detection of a power level normally sufficient to synchronize, with N ' ⁇ N.
• the radio module tries to synchronize on the BCCH frequencies included in the last received list of BCCH frequencies, and whose power is greater than -105dBm. These attempts are made for example in order of decreasing power.
• a step E37 for generating a third intermediate interference signal S3 is carried out with a third probability of interference P3 less than 100% and greater than P2. Then we go to a step E38. Otherwise, we return to step E36.
• the probability P3 is for example such that:
• N ' is the number of cells belonging to the neighborhood of the last carrier. A weighting of 1.5 is applied to these cells relative to the remaining (N-N ') cells. 0.5 s is the maximum time allowed by 3GPP 05.08 ($ 6.2) to synchronize a BCCH carrier in the initial selection phase. Steps E36 and E37 form a third intermediate detection phase.
• this third phase of intermediate detection can be repeated several times. For example, it can be repeated twice, with numbers N'i and N '2 (such as: N'i ⁇ N' 2 ) and intermediate interference signals S3i and S32, generated with P3i interference probabilities and P3 2 (such as: P3i ⁇ P32).
• step E38 it is detected whether the following condition C4 is verified: there are N "radio communication channels on which the radiocommunication module can not synchronize despite the detection of a power level normally sufficient to synchronize, with : N ' ⁇ N " ⁇ N.
• the N "radiocommunication channels comprise the aforementioned N 'radiocommunication channels
• a step E39 for generating a fourth intermediate interference signal S4 is carried out with a fourth probability of interference P4 less than 100% and greater than P3. Then we go to a step E310.
• the probability P4 is for example such that:
• Steps E38 and E39 form a fourth phase of intermediate detection.
• this fourth intermediate detection phase may be repeated several times. For example, it can be repeated twice, with numbers N "i and N" 2 (such as: N "i ⁇ N" 2 ) and intermediate scrambling signals S4i and
• step E310 it is detected whether the following condition C5 is verified: there are N radio channels on which the radio module can not synchronize despite the detection of a power level normally sufficient to synchronize. If this condition C5 is verified, a step E311 of generating a final jamming signal S5 with a probability of interference P5 equal to 100% is carried out. Then we go to an end step E312.
• durations D2, D3 and D4 for generating signals S2, S3 and S4 are given in relative relation to the last signal generated.
• step E42 After a start step E41, a step E42 in which the reception of the first intermediate scrambling signal Sl (see step E33 of FIG. 3) is detected. In the event of positive detection in step E42, a step E43 of triggering of at least a first intermediate action A1 is triggered. Then we go to a step E44. Otherwise, return to step E42.
• step E44 the reception of the second intermediate scrambling signal S2 is detected (see step E35 of FIG. 3). In case of positive detection at the stage
• step E44 one goes to a step E45 triggering at least a second intermediate action A2. Then we go to a step E46. Otherwise, we return to step E44.
• step E46 the reception of the third intermediate scrambling signal S3 is detected (see step E37 of FIG. 3).
• a step E47 of tripping of at least a third intermediate action A3 is started. Then we go to a step E48. Otherwise, we return to step E46.
• step E48 the reception of the fourth intermediate scrambling signal S4 is detected (see step E39 of FIG. 3).
• a step E49 of triggering of at least a fourth intermediate action A4 is triggered. Then we go to a step E410. Otherwise, return to step E48.
• step E410 the reception of the fifth intermediate scrambling signal S5 is detected (see step E311 of FIG. 3).
• a step E411 of triggering of at least one final action A5 is started.
• the client application can determine what behavior it can adopt taking into account the interference probability with which each scrambling signal is generated.
• actions A1 to A5 are for example the following:
• actions Al and / or A2 the client application (which furthermore can know that the car is immobile) goes into first-level defensive mode (increase of the calculation power of the processor to allow a diagnosis of the situation at speed maximum, complete diagnosis of the car's break-in sensors;
• Action A3 the client application activates the contact cutoff for a predetermined duration (for example 15 seconds) corresponding to the diagnostic time until the generation of the next intermediate interference signal by the scrambling detection algorithm according to the invention (see Figure 3);
• action A5 triggering an alarm (local and / or remote).
• the technique of the invention achieves this dual purpose. It is clear that many other embodiments of the invention can be envisaged.
• one of the intermediate actions (for example A3) consists in interrupting the scrambling detection method. Detection phases not yet executed are not executed.
• the scrambling signals S1 to S5 are transmitted, via the radio network or via another communication network, to a remote device (a monitoring server for example), instead of or in addition to the transmission. (internal to the radiocommunication module) to the client application embedded on the radiocommunication module.
• the remote equipment can thus take this into account in making a decision to trigger at least one intermediate action (for example, triggering a remote alarm).

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• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Mechanical Engineering (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• Mobile Radio Communication Systems (AREA)

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• 2007
  • 2007-07-13 FR FR0756477A patent/FR2918828B1/fr not_active Expired - Fee Related
• 2008
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  • 2008-07-11 EP EP08775023A patent/EP2168283A1/de not_active Withdrawn
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  • 2008-07-11 WO PCT/EP2008/059106 patent/WO2009010470A1/fr active Application Filing

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