Patent ID: 12212408

EMBODIMENTS

Security of downlink control information in cellular communication networks may be improved by the procedures described herein. In some embodiments of the present invention, possible downlink control information of a first User Equipment, UE, may be scrambled and the scrambled version of the possible downlink control information may be checked to make sure that the scrambled version of said possible downlink control information for the first UE defines valid downlink control information and if so, a jamming transmission may be scheduled based on the scrambled version of said possible downlink control information.

Thus, the scrambled version of the possible downlink control information may be decoded by an eavesdropper, such as a second UE. That is to say, the eavesdropper may decode the scrambled version of the possible downlink control information to identify the downlink control information associated with the jamming transmission. The eavesdropper may therefore decode a misleading resource assignment. So for example in case of downlink data transmission, a Base Station, BS, may transmit data to the first UE on a resource assigned to the first UE. The BS may also transmit the jamming transmission, such as some other data or dummy transport blocks, on a jamming resource, thereby misleading the eavesdropper. Similarly, in case of uplink data transmission, the first UE may transmit data to the BS on the resource assigned to the first UE and the jamming transmission on the jamming resource to mislead the eavesdropper.

FIG.1illustrates an exemplary network scenario in accordance with at least some embodiments of the present invention. The exemplary network scenario ofFIG.1may comprise first UE110, second UE120, BS130and core network140. First UE110and second UE120may comprise, for example, a smartphone, a cellular phone, a Machine-to-Machine, M2M, node, Machine-Type Communications node, an Internet of Things, IoT, node, a car telemetry unit, a laptop computer, a tablet computer or, indeed, any kind of suitable wireless user device or mobile station, i.e., a terminal.

In the exemplary network scenario system ofFIG.1, first UE110may be attached, or connected to, BS130over air interface115for wireless communications. BS130may be considered for example as a serving BS of first UE110. Air interface115between first UE110and BS130may be configured in accordance with a Radio Access Technology, RAT, which both first UE110and BS130are configured to support. Air interface115may comprise, e.g., one or more beams between first UE110and BS130.

Examples of cellular RATs include Long Term Evolution, LTE, New Radio, NR, which may also be known as fifth generation, 5G, and MulteFire. For example in the context of LTE, BS130may be referred to as eNB while in the context NR, BS130may be referred to as gNB. In any case, embodiments of the present invention are not restricted to any particular wireless technology. Instead, embodiments of the present invention may be exploited in any wireless communication system wherein it is desirable to secure downlink control information.

BS130may be connected, directly or via at least one intermediate node, with core network140. BS130may be connected to core network140via wired connection135. Core network140may be, in turn, coupled with another network (not shown inFIG.1), via which connectivity to further networks may be obtained, for example via a worldwide interconnection network.

In some embodiments of the present invention, first UE110and BS130may be legitimate participants of the communication while second UE120may be a potential eavesdropper. That is to say, first UE110and BS130would like to communicate in a secure manner over air interface115while second UE120may try to intercept and decrypt communications between BS130and first UE110, even though second UE120is not a legitimate receiver of said communications.

FIG.1shows an exemplary network scenario, wherein an eavesdropper, such as second UE120, is trying to listen and decode the data transmissions between BS130, such as a gNB, and first UE110. Especially when the data transmissions between BS130and first UE110are performed over a long period of time, the feasibility of cracking down the higher layer security protocols and decoding the exact information becomes a reality.

So security of data transmissions via wireless networks remains an important issue. For instance, it is critical to guarantee that private data are accessible only to legitimate receivers, such as first UE110, rather than eavesdroppers and impostors, such as second UE120. In many cases, jamming and eavesdropping are two primary attacks at the physical layer of a wireless network.

In some embodiments of the present invention, BS130may protect downlink control channel transmissions, such as a Physical Downlink Control Channel, PDCCH, by encrypting, i.e., scrambling, the downlink control information of first UE110. That is to say, BS120, such as a gNB, may encrypt bits transmitted on PDCCH. In general, downlink control information may refer to Downlink Control Information, DCI, as specified for example in 3rd Generation Partnership Project, 3GPP, standard specifications.

For instance, in case of a downlink data transmission, single downlink control channel transmission, transmitted by BS130, may be used to make sure that scrambled version of possible downlink control information schedules a downlink shared channel, such as a Physical Downlink Shared Channel, PDSCH, for first UE110and another downlink shared channel, such as a jamming resource, to mislead eavesdroppers, such as second UE120. Similarly, in case of an uplink data transmission single downlink control channel transmission may be used to make sure that the scrambled version of the possible downlink control information schedules an uplink shared channel, such as a Physical Uplink Shared Channel, PUSCH, for first UE110and another uplink shared channel, i.e., a jamming resource, to mislead eavesdroppers, such as second UE120.

In addition, Physical Layer Security, PLS, may be used to improve secrecy of wireless communication. PLS exploits intrinsic randomness of a transmission channel, e.g., uniqueness of a channel model between two physical positions in space and time. Physical parameters may evolve randomly on a less-than-a-second basis for example, to guarantee the security at the physical layer. PLS key to be used for encryption may be based on the transmission channel, direction of arrival/departure, transmit/receive beam index, pathloss, etc. For instance, a PLS key associated with, or of, first UE110may refer to a key that is derived based on the transmission channel between first UE110and BS130. The PLS key of first UE110may be derived at both, first UE110and BS130, independently, e.g., by assuming reciprocity of the transmission channel between first UE110and BS130.

PLS may be used to create an extra shield of protection for example, to hinder success of various attacks. Also, PLS may be a good alternative compared to security protocols at higher levels, because a priori distribution of a security key may not be required to ensure secrecy of the communication. Thus, additional information exchange may be avoided. For instance, symmetric-key cryptosystems may be efficient in terms of computation, but such cryptosystems cause delay and decrease throughput. On the other hand, public-key algorithms may be computationally expensive and energy-consuming while causing delay and decreasing throughput as well. PLS is thus suitable, e.g., for IoT devices, because IoT devices typically have limited resources, such as processing power, communication capabilities and battery. Security of IoT devices has developed from a nice-to-have add-on for both, for embedded solutions as well as for communication standards, to a must-have due to numerous attacks, e.g., against networked cars or medical devices.

There is therefore also a need to design new and robust security protocols based on PLS. The current solutions used at the application level do not seem to be efficient and secure enough for emerging wireless communication networks, such as 5G/NR networks. PLS may be thus used as an alternative or to provide additional level of protection to formulate a well-integrated security solution together with other solutions, to efficiently safeguard confidentiality and privacy of data communications for example in 5G/NR wireless networks.

So even though embodiments of the present invention may be applied in any wireless communication system wherein it is desirable to secure downlink control information, it is recognized that at least in the context of 5G/NR there is a need to enhance security at the physical layer using PLS. For instance, at least one challenge in 5G/NR networks at the moment is that there is no solution to provide an extra level of security for data transmissions.

Some embodiments of the present invention address the above mentioned challenges by providing a security scheme, wherein uniqueness of a wireless channel and/or transmitted signal may be exploited by using PLS keys for scrambling downlink control information, thereby enabling secure communication and avoiding jamming and eavesdropping.

FIG.2illustrates securing downlink control information in accordance with at least some embodiments of the present invention. InFIG.2, DCI is denoted by210, scrambling sequence generated by PLS is denoted by220, scrambled DCI210is denoted by230and Cyclic Redundancy Check, CRC, of scrambled DCI230is denoted by240. DCI210may be referred to as downlink control information of a user equipment, such as first UE110, in general. Scrambling sequence generated by PLS may be referred to as a PLS key as well. In some embodiments of the present invention, scrambled DCI230may be referred to as a scrambled version of DCI210.

DCI210may be for a subsequent downlink or uplink data transmission, such as PDSCH or PUSCH, respectively, and DCI210may be transmitted on PDCCH for example. In general, PDCCH may be referred to as a single downlink control channel transmission. For transmission of DCI210, BS130may use protection of data by encrypting, i.e., scrambling, DCI210by encrypting at least some bits transmitted on the PDCCH. DCI210may be referred to as a possible DCI for first UE110as well.

Using resource assignment for downlink data transmission as an example, BS130may use DCI210of first UE110and scramble DCI210using a PLS key associated with UE110. That is to say, DCI210may be scrambled by BS130using scrambling sequence generated by PLS220, wherein scrambling sequence generated by PLS220is available at UE110and BS130. BS130may hence generate scrambled DCI230based on DCI210and scrambling sequence generated by PLS220.

Upon generating scrambled DCI230, BS130may generate CRC240by calculating a CRC value over scrambled DCI230. Moreover, BS130may attach CRC240, such as distributed CRC in NR, to scrambled DCI230and encode scrambled DCI230along with CRC240. As CRC240may be attached to scrambled DCI230, both first UE110and second UE120may calculate a CRC value upon receiving scrambled DCI230along with CRC240, and determine that CRC has passed if decoding of scrambled DCI230was successful, i.e., the calculated CRC value corresponds to CRC240.

In some embodiments of the present invention, BS130may ensure that scrambled DCI230provides at least one valid resource assignment, or allocation, for a jamming resource, i.e., for a jamming transmission. The jamming resource may be a combination of a time and a frequency resource, possibly controlled by BS130. That is to say, BS130may determine, based on scrambled DCI230, whether a jamming resource can be scheduled. The scrambled DCI, i.e., DCI230without descrambling, may indicate the jamming resource. That is to say, if an eavesdropper decodes scrambled DCI230, without descrambling, the decoded scrambled DCI230may indicate the jamming resource. Upon generation of scrambled DCI230and determining that the jamming resource can be scheduled, BS130may schedule the jamming transmission based on scrambled DCI230.

Scrambled DCI230may be then transmitted. So if an eavesdropper, such as second UE120, receives scrambled DCI230and tries to decode it, the decoding may succeed even without descrambling. Consequently, second UE120may determine the resource assignment of the jamming resource based on the decoded scrambled DCI230and assume that a data transmission intended to, or from, first UE110will take place on the jamming resource.

In addition, BS130may ensure that scrambled DCI230provides other DCI fields without descrambling so that any eavesdropper, such as second UE120, may perform successful decoding of a downlink shared channel indicated by the at least one valid jamming resource assignment. For instance, BS130may determine that scrambled DCI230provides the at least one jamming resource assignment without descrambling, e.g., by checking that decoded scrambled DCI230defines the at least one valid jamming resource assignment, even without descrambling by any eavesdropper. BS130may also transmit a downlink shared channel, such as PDSCH, on the at least one valid jamming resource, to ensure that there is at least one data transmission in a field defined by decoded scrambled DCI230, even without descrambling. For instance, a jamming message may be transmitted on the at least one valid jamming resource instead of transmitting actual data of first UE110.

Alternatively, or in addition, only some, but not all, fields in DCI210may be scrambled to get scrambled DCI230. That is to say, only a part of DCI210may be scrambled using a PLS key associated with first UE110to generate scrambled DCI230and scrambled DCI230may hence comprise a part which is not scrambled. Thus, more flexibility may be provided to BS130for scheduling.

Moreover, in some embodiments of the present invention, a multi-UE scenario with security needs may be addressed. For example, BS130may transmit multiple scrambled DCIs wherein each scrambled DCI is associated with a different UE and scrambled with a PLS key of the UE in question. That is to say, each UE may have different DCI payload. In such a case as well, BS130may also ensure that the transmission of multiple scrambled DCIs defines at least one valid jamming resource assignment without descrambling, thereby saving overhead by not assigning multiple jamming resources, such as jamming PDSCHs.

Upon generating scrambled DCI230, and possible CRC240as well, BS130may transmit two downlink shared channels, such as PDSCHs. For instance, BS130may transmit data to first UE110on a resource indicated by scrambled DCI230after descrambling, i.e., on a resource indicated by DCI210. That is to say, said data may be data intended for first UE110and the resource indicated by scrambled DCI230after descrambling may be actual content of DCI210. In addition, BS130may transmit a jamming message for eavesdroppers, such as second UE120, on a resource indicated by scrambled DCI230without descrambling, i.e., scrambled DCI230which is only decoded, but not descrambled, by eavesdroppers. Thus, eavesdroppers may be misled due to the transmission of the jamming message on the jamming resource.

First UE110may then, upon receiving scrambled DCI230, decode scrambled DCI230and descramble the decoded scrambled DCI using a PLS key associated with first UE110. First UE110may thus recover the actual DCI210and identify the resource indicated by scrambled230after decoding and descrambling. Consequently, first UE110may receive data from BS130on the resource indicated by DCI210and for example decode a correct downlink shared channel, such as PDSCH, transmission from BS130. That is to say, first UE110may communicate with BS130on the resource indicated by DCI210, i.e., the descrambled DCI.

An eavesdropper, such as second UE120, may decode scrambled DCI230upon receiving it from BS130but the eavesdropper may not be able to descramble decoded scrambled DCI230, because the eavesdropper does not know the PLS key associated with first UE110. In some embodiments, if CRC240is used, the eavesdropper may decode scrambled DCI230as CRC passes often if there is no error in the transmission. Thus, the eavesdropper may decode a misleading resource assignment, i.e., the resource assignment indicated by scrambled DCI230without descrambling, which is for the jamming resource. As BS130may transmit the jamming message on the jamming resource and the eavesdropper may consequently receive the jamming message. So if the eavesdropper is for example an imposter, the eavesdropper may transmit feedback, such as HARQ-ACK, for the jamming message and BS130may identify presence of the imposter based on the received feedback. In some embodiments, the jamming message may comprise for example transport blocks, such as dummy transport blocks.

Similar mechanism may be used for uplink data transmissions as well. In such a case, the resources indicated by DCI210and scrambled DCI230without descrambling may be uplink shared channels, such as PUSCH, resources. After reception, first UE110may decode and descramble scrambled DCI230and then, first UE110may transmit data to BS130on the resource indicated by DCI210. That is to say, first UE110may communicate with BS130on the resource indicated by DCI210, i.e., the descrambled DCI.

First UE110may also transmit a jamming message on a resource indicated by the scrambled DCI230without descrambling because an eavesdropper, such as second UE120, may try to listen to transmissions of first UE110. The eavesdropper may hence become busy with decoding of the jamming message and consequently the transmission of data to BS130on the resource indicated by DCI210becomes more secure. That is to say, first UE110may decode scrambled DCI230to determine that decoded scrambled DCI230provides a valid DCI for a jamming transmission and then transmit a jamming message, i.e., a jamming transmission on a resource indicated by said valid DCI. First UE110may further descramble decoded scrambled DCI230, corresponding to said valid DCI, to get DCI210.

If an eavesdropper, i.e., an imposter, tries to replace first UE110and BS130and uses the jamming resource for transmissions, such as PDSCH and PUSCH transmissions, to schedule HARQ-ACK or send retransmission requests for example, BS130may identify the imposter, or a threat in general, based on the received transmission on the resource indicated by scrambled DCI230, i.e., the transmission received on the jamming resource. That is to say, BS130may identify a threat because there is a transmission on a resource that is not assigned for a given UE, such as first UE110.

FIG.3illustrates securing downlink control information and CRC in accordance with at least some embodiments of the present invention. InFIG.3, DCI is denoted by310, scrambling sequence generated by PLS is denoted by320, scrambled DCI310is denoted by330and CRC of scrambled DCI330is denoted by340, similarly as inFIG.2. In addition, second scrambling sequence is denoted by325and scrambled CRC is denoted by350inFIG.3.

FIG.3demonstrates two-step scrambling, wherein DCI310may be first scrambled using scrambling sequence generated by PLS320, to get scrambled DCI330, similarly as DCI210may be scrambled using scrambling sequence generated by PLS220, to get scrambled DCI230inFIG.2. In addition, CRC340may be scrambled to get scrambled CRC350. CRC340may be scrambled upon calculating a CRC check value, or bits, for scrambled DCI330for example. In some embodiments, CRC340may be scrambled using another, second scrambling sequence325, wherein second scrambling sequence325may not be generated using PLS. That is to say, second scrambling sequence may be different compared to the PLS key associated with first UE110, i.e., a first scrambling sequence.

That is to say, second scrambling sequence325may not be a PLS generated parameter but second scrambling sequence325may be used together with a PLS key to provide additional flexibility for BS130to schedule the resource assignment of UE110and jamming resource assignment, i.e., the two transmissions. In addition, second scrambling sequence325may be used to provide extra security. For instance, CRC340may be scrambled using second scrambling sequence325on top of Radio Network Temporary Identifier, RNTI, similarly as defined in 3GPP standard specifications. In some embodiments, second scrambling sequence325may be known to BS130and both UEs, UE110and UE120, or BS130and UE110only. Second scrambling325sequence may be preconfigured, e.g., like RNTI.

In some embodiments of the present invention, a PLS key associated with UE110may correspond to second scrambling sequence325. That is to say, a set of second scrambling sequences325may exist and BS130may select one sequence325from the set of scrambling sequences325, wherein the selected scrambling sequence325corresponds to the PLS key associated with UE110. Thus there may be a one-to-one relation with the selected second scrambling sequence325and the PLS key associated with UE110such that same understanding about second scrambling sequence325is available at both, BS130and UE110, and both may select same second scrambling sequence325based on the PLS key associated with UE110. If the selected second scrambling sequence does not define valid DCI for a jamming transmission together with scrambled DCI330, BS130may change second scrambling sequence325, e.g., to another sequence from the set. BS130may then check again whether the changed second scrambling sequence defines valid DCI for a jamming transmission together with scrambled DCI330.

In some embodiments of the present invention, CRC check with multiple second scrambling sequences325may be applied at the receiver side, such as at UE110, to find a PLS key that matches to the used second scrambling sequence325. Hence, BS130may have more flexibility as there may be multiple options for scrambled DCI330, which further makes it easier to schedule a jamming resource, such as PDSCH or PUSCH, while also transmitting on the resource assigned for UE110.

FIG.4illustrates an exemplary process in accordance with at least some embodiments of the present invention. The exemplary process may be performed by BS130, such as a gNB, for example. In the beginning of the exemplary process BS130may determine that there is new data available to schedule to UE110, i.e., for a downlink data transmission, and for example that UE110is capable of using PLS. Nevertheless, the exemplary process may be applied similarly if BS130determines that there is new data to schedule for a transmission from UE110, i.e., for an uplink data transmission.

Upon determining that there is new data available for transmission to UE110, BS130may, at step410, decide about transmission parameters for a downlink control channel transmission, such as a PDCCH transmission. Said transmission parameters may comprise for example DCI format, aggregation level, etc., for the downlink control channel transmission. At step420, BS130may consider scheduling information for the downlink data transmission, such as PDSCH scheduling information. The scheduling information may comprise for example a resource assignment of first UE110, such as a time and a frequency resource. The scheduling information for the downlink data transmission may eventually decide exact content of a DCI, scrambled or not, to be transmitted.

At step430, BS130may scramble the DCI of UE110, such as DCI210inFIG.1, using a PLS key associated with UE110. BS130may also determine, at step430, whether a resource for jamming, i.e., a jamming resource, may be assigned by BS130based on the scrambled DCI. That is to say, BS130may determine, based on the scrambled DCI, whether a jamming resource can be scheduled, wherein the scrambled DCI indicates the jamming resource, if for example decoded by an eavesdropper, such as second UE120, without descrambling. BS130may determine that the scrambled DCI defines valid downlink control information by identifying a possibility to schedule another transmission, such as the jamming transmission, by BS130.

For instance, BS130may determine whether the jamming resource may be assigned by checking whether the scrambled DCI of UE110indicates, or defines, valid DCI without descrambling. The valid DCI may for example indicate a time and a frequency resource controlled by BS130. That is to say, BS130may check the scrambled DCI to determine whether the scrambled DCI, i.e., a scrambled version of at least one possible DCI of first UE110, defines a valid DCI. BS130may for example check that the scrambled DCI defines a DCI in a correct format, such as in a format that is specified in 3GPP standard specifications.

If it is determined, at step430, that the scrambled DCI does not indicate a valid DCI, BS130may decide not to schedule a jamming transmission based on the scrambled DCI and the exemplary process may proceed to step435. At step435, BS130may determine whether a maximum number of attempts is reached. If the maximum number of attempts has not been reached, the exemplary process may loop back to step420. However, if it is determined at step435that the maximum number of attempts has been reached, the exemplary process may proceed to step445.

At step445, BS130may schedule first UE110with a resource and the resource may be indicated by a DCI of first UE110, such as DCI210inFIG.2, and the DCI of first UE110may be scrambled using a PLS key of first UE110for example, such as scrambling sequence220inFIG.2, to generate a scrambled DCI of first UE110, such as scrambled DCI230inFIG.2. After that, BS130may perform control channel encoding and transmit in a downlink control channel transmission the encoded scrambled DCI only, without scheduling any jamming resource.

On the other hand, if it is determined, at step430, that the scrambled DCI defines a valid DCI, e.g., if decoded but not descrambled by an eavesdropper, the exemplary process may proceed to step440. At step440, BS130may also schedule first UE110with a resource and the resource may be indicated by a DCI of first UE110and the DCI of first UE110may be scrambled using a PLS key associated with first UE110for example, to generate a scrambled DCI of first UE110. After that, BS130may schedule the jamming transmission based on the scrambled DCI of first UE110. BS130may perform control channel encoding and transmit in a downlink control channel transmission comprising the encoded scrambled DCI, wherein the scrambled DCI indicates a valid DCI, such as a resource for a jamming transmission, without descrambling by an eavesdropper.

That is to say, at steps420-435, BS130may check multiple possibilities to make sure that it can schedule two transmissions, such as PDSCH transmissions, one with the scrambled DCI without descrambling and one also with actual DCI, i.e., with the scrambled DCI after descrambling. So if it is determined, at step430, that the jamming resource cannot be scheduled, another resource, i.e., another DCI, may be assigned for first UE110if the process goes back to step430via steps435and420. An indication about said another DCI may be scrambled using the PLS key associated with first UE110. BS130may then determine, based on the scrambled indication about said another DCI, whether another valid DCI, i.e., a jamming transmission may be scheduled. If it is determined that said another valid DCI can be scheduled, BS130may transmit the scrambled another DCI. When both transmission may be scheduled, BS130may proceed to the next step, i.e., to step440.

In some embodiments of the present invention, other PLS enhancements may be applied as well, on top of the embodiments presented herein.

FIG.5illustrates an example apparatus capable of supporting at least some embodiments of the present invention. Illustrated is device500, which may comprise, for example, first UE110or BS130ofFIG.1, or device500may be configured to control the functioning thereof, possibly when installed therein. Comprised in device500is processor510, which may comprise, for example, a single- or multi-core processor wherein a single-core processor comprises one processing core and a multi-core processor comprises more than one processing core. Processor510may comprise, in general, a control device. Processor510may comprise more than one processor. Processor510may be a control device. Processor510may comprise at least one application-specific integrated circuit, ASIC. Processor510may comprise at least one field-programmable gate array, FPGA. Processor510may be means for performing method steps in device500. Processor510may be configured, at least in part by computer instructions, to perform actions.

A processor may comprise circuitry, or be constituted as circuitry or circuitries, the circuitry or circuitries being configured to perform phases of methods in accordance with embodiments described herein. As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations, such as implementations in only analog and/or digital circuitry, and (b) combinations of hardware circuits and software, such as, as applicable: (i) a combination of analog and/or digital hardware circuit(s) with software/firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

Device500may comprise memory520. Memory520may comprise random-access memory and/or permanent memory. Memory520may comprise at least one RAM chip. Memory520may comprise solid-state, magnetic, optical and/or holographic memory, for example. Memory520may be at least in part accessible to processor510. Memory520may be at least in part comprised in processor510. Memory520may be means for storing information. Memory520may comprise computer instructions that processor510is configured to execute. When computer instructions configured to cause processor510to perform certain actions are stored in memory520, and device500overall is configured to run under the direction of processor510using computer instructions from memory520, processor510and/or its at least one processing core may be considered to be configured to perform said certain actions. Memory520may be at least in part comprised in processor510. Memory520may be at least in part external to device500but accessible to device500.

Device500may comprise a transmitter530. Device500may comprise a receiver540. Transmitter530and receiver540may be configured to transmit and receive, respectively, information in accordance with at least one cellular or non-cellular standard. Transmitter530may comprise more than one transmitter. Receiver540may comprise more than one receiver. Transmitter530and/or receiver540may be configured to operate in accordance with Global System for Mobile communication, GSM, Wideband Code Division Multiple Access, WCDMA, 5G/NR, Long Term Evolution, LTE, IS-95, Wireless Local Area Network, WLAN, Ethernet and/or Worldwide interoperability for Microwave Access, WiMAX, standards, for example.

Device500may comprise a near-field communication, NFC, transceiver550. NFC transceiver550may support at least one NFC technology, such as NFC, Bluetooth, Wibree or similar technologies.

Device500may comprise user interface, UI,560. UI560may comprise at least one of a display, a keyboard, a touchscreen, a vibrator arranged to signal to a user by causing device500to vibrate, a speaker and a microphone. A user may be able to operate device500via UI560, for example to accept incoming telephone calls, to originate telephone calls or video calls, to browse the Internet, to manage digital files stored in memory520or on a cloud accessible via transmitter530and receiver540, or via NFC transceiver550, and/or to play games.

Device500may comprise or be arranged to accept a user identity module570. User identity module570may comprise, for example, a Subscriber Identity Module, SIM, card installable in device500. A user identity module570may comprise information identifying a subscription of a user of device500. A user identity module570may comprise cryptographic information usable to verify the identity of a user of device500and/or to facilitate encryption of communicated information and billing of the user of device500for communication effected via device500.

Processor510may be furnished with a transmitter arranged to output information from processor510, via electrical leads internal to device500, to other devices comprised in device500. Such a transmitter may comprise a serial bus transmitter arranged to, for example, output information via at least one electrical lead to memory520for storage therein. Alternatively to a serial bus, the transmitter may comprise a parallel bus transmitter. Likewise processor510may comprise a receiver arranged to receive information in processor510, via electrical leads internal to device500, from other devices comprised in device500. Such a receiver may comprise a serial bus receiver arranged to, for example, receive information via at least one electrical lead from receiver540for processing in processor510. Alternatively to a serial bus, the receiver may comprise a parallel bus receiver.

Device500may comprise further devices not illustrated inFIG.5. For example, where device500comprises a smartphone, it may comprise at least one digital camera. Some devices500may comprise a back-facing camera and a front-facing camera, wherein the back-facing camera may be intended for digital photography and the front-facing camera for video telephony. Device500may comprise a fingerprint sensor arranged to authenticate, at least in part, a user of device500. In some embodiments, device500lacks at least one device described above. For example, some devices500may lack a NFC transceiver550and/or user identity module570.

Processor510, memory520, transmitter530, receiver540, NFC transceiver550, UI560and/or user identity module570may be interconnected by electrical leads internal to device500in a multitude of different ways. For example, each of the aforementioned devices may be separately connected to a master bus internal to device500, to allow for the devices to exchange information. However, as the skilled person will appreciate, this is only one example and depending on the embodiment various ways of interconnecting at least two of the aforementioned devices may be selected without departing from the scope of the present invention.

FIG.6is a flow graph of a first method in accordance with at least some embodiments of the present invention. The phases of the illustrated first method may be performed by a BS, such as BS130, or by a control device configured to control the functioning thereof, possibly when installed therein. The first method may be for using a single downlink control channel transmission to schedule a data transmission for a user equipment and a jamming transmission for an eavesdropper.

The first method may comprise, at step610, determining at least one possible downlink control information for the user equipment to schedule the data transmission. The first method may also comprise, at step620, checking a scrambled version of the at least one possible downlink control information to determine whether the scrambled version of the at least one possible downlink control information defines valid downlink control information. In addition, the first method may comprise, at step630, transmitting the scrambled version of the at least one possible downlink control information and scheduling the data transmission based on the at least one possible downlink control information. Finally, the first method may comprise, at step640, if it is determined that the scrambled version of the at least one possible downlink control information defines valid downlink control information, scheduling the jamming transmission based on the scrambled version of the at least one possible downlink control information.

FIG.7is a flow graph of a second method in accordance with at least some embodiments of the present invention. The phases of the illustrated second method may be performed by a UE, such as first UE110, or by a control device configured to control the functioning thereof, possibly when installed therein.

The second method may comprise, at step710, receiving a scrambled version of at least one downlink control information of the user equipment. The second method may also comprise, at step720, decoding the scrambled version of the at least one downlink control information. At step730, the first method may comprise determining that the decoded scrambled version of the at least one downlink control information provides valid downlink control information for a jamming transmission. In addition, the second method may comprise, at step740, transmitting data on a resource indicated by the at least one downlink control information. Finally, the second method may comprise, at step750, transmitting the jamming transmission on a resource indicated by said valid downlink control information.

It is to be understood that the embodiments of the invention disclosed are not limited to the particular structures, process steps, or materials disclosed herein, but are extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. It should also be understood that terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting.

Reference throughout this specification to one embodiment or an embodiment means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Where reference is made to a numerical value using a term such as, for example, about or substantially, the exact numerical value is also disclosed.

As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary. In addition, various embodiments and example of the present invention may be referred to herein along with alternatives for the various components thereof. It is understood that such embodiments, examples, and alternatives are not to be construed as de facto equivalents of one another, but are to be considered as separate and autonomous representations of the present invention.

In an exemplary embodiment, an apparatus, such as, for example, first UE110or BS130, may comprise means for carrying out the embodiments described above and any combination thereof.

In an exemplary embodiment, a computer program may be configured to cause a method in accordance with the embodiments described above and any combination thereof. In an exemplary embodiment, a computer program product, embodied on a non-transitory computer readable medium, may be configured to control a processor to perform a process comprising the embodiments described above and any combination thereof.

In an exemplary embodiment, an apparatus, such as, for example, first UE110or BS130, may comprise at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to perform the embodiments described above and any combination thereof.

Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the preceding description, numerous specific details are provided, such as examples of lengths, widths, shapes, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.

While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited, except as by the claims set forth below.

The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of also un-recited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of “a” or “an”, that is, a singular form, throughout this document does not exclude a plurality.

INDUSTRIAL APPLICABILITY

At least some embodiments of the present invention find industrial application in communication networks, wherein secure transmission over air interface is required, such as in networks operating in accordance with 3GPP standards.

Acronyms List

3GPP 3rd Generation Partnership ProjectBS Base StationCRC Cyclic Redundancy CheckCSI Channel State InformationDCI Downlink Control InformationFDD Frequency Division DuplexingGSM Global System for Mobile communicationIMSI International Mobile Subscriber IdentityIoT Internet of ThingsLTE Long-Term EvolutionM2M Machine-to-MachineMTC Machine-Type CommunicationsNFC Near-Field CommunicationPLS Physical Layer SecurityNR New RadioPDCCH Physical Downlink Control ChannelPDSCH Physical Downlink Shared ChannelPUSCH Physical Uplink Shared ChannelRAT Radio Access TechnologyRNTI Radio Network Temporary IdentifierSIM Subscriber Identity ModuleUE User EquipmentUI User InterfaceWCDMA Wideband Code Division Multiple AccessWiMAX Worldwide Interoperability for Microwave AccessWLAN Wireless Local Area Network

REFERENCE SIGNS LIST

110First UE, e.g., a legitimate receiver or transmitter120Second UE, e.g., an eavesdropper130Base Station115, 135Interfaces140Core network210, 310DCI of first UE 110220, 320Scrambling sequence of PLS key230, 330Scrambled DCI240, 340CRC350Scrambled CRC410-445Process steps in FIG. 4500-570Structure of the apparatus of FIG. 5610-640Phases of the first method of FIG. 6710-750Phases of the second method of FIG. 7