User Plane Traffic Processing for Emergency Cases

Abstract

An exemplary embodiment of the present disclosure relates to UP traffic processing for emergency cases. A first terminal device determines that UP traffic is communicated between the first terminal device and the second terminal device without confidentiality protection. The first terminal device determines that UP traffic is communicated between the first terminal device and the second terminal device without integrity protection or with partial integrity protection. The first terminal device transmits a message to the second terminal device indicating that UP traffic is communicated without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection. Then, the first terminal device communicates UP traffic between the first terminal device and the second terminal device without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection.

Description

[Technical field]

[0001] Various example embodiments of the present disclosure relate generally to the field of telecommunications, and more particularly, to a device, method, apparatus, and computer-readable storage medium for processing user plane (UP) traffic for emergency cases of 5G ProSe UE-network relay services. [Background technology]

[0002] The fifth generation (5G) system supports a proximity-based service (ProSe) function. The 5G ProSe function may comprise 5G ProSe Direct Discovery, 5G ProSe Direct Communication, and 5G ProSe UE-to-Network (U2N) Relay. In the 5G ProSe UE-to-Network Relay function, a remote user equipment (UE) may connect to the UE-to-Network Relay via a PC5 interface using 5G ProSe Direct Communication to communicate with a data network via the UE-to-Network Relay and the 5G network. The 5G ProSe UE-to-Network Relay function supports emergency services in the UE-to-Network Relay. Protection of user plane (UP) traffic between the remote UE and the UE-to-Network Relay in emergency cases needs to be studied. Summary of the Invention

[0003] Generally, the exemplary embodiments of the present disclosure provide a solution for handling UP traffic for emergency cases.

[0004] In a first aspect, a first terminal device is provided. The first terminal device includes at least one processor and at least one memory that stores instructions. When the instructions are executed by the at least one processor, the instructions cause the first terminal device to at least determine that UP traffic is communicated between the first terminal device and the second terminal device without confidentiality protection, determine that UP traffic is communicated between the first terminal device and the second terminal device without integrity protection or with partial integrity protection, send a message to the second terminal device indicating that UP traffic is communicated without confidentiality or integrity protection, or with no confidentiality protection and with partial integrity protection, and communicate UP traffic between the first terminal device and the second terminal device without confidentiality or integrity protection, or with no confidentiality protection and with partial integrity protection.

[0005] In a second aspect, a second terminal device is provided. The second terminal device includes at least one processor and at least one memory that stores instructions. When the instructions are executed by the at least one processor, the instructions cause the second terminal device to receive a message from the first terminal device indicating that UP traffic is to be communicated between the first terminal device and the second terminal device without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection, and to communicate UP traffic between the first terminal device and the second terminal device without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection, based on the message.

[0006] In a third aspect, a method is provided, the method including: determining in a first terminal device that UP traffic is communicated between a first terminal device and a second terminal device without confidentiality protection, determining that UP traffic is communicated between the first terminal device and the second terminal device without integrity protection or with partial integrity protection, sending a message to the second terminal device indicating that UP traffic is communicated without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection, and communicating UP traffic between the first terminal device and the second terminal device without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection.

[0007] In a fourth aspect, a method is provided, the method including: receiving a message from a first terminal device at a second terminal device indicating that UP traffic is communicated between a first terminal device and a second terminal device without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection, and communicating UP traffic between the first terminal device and the second terminal device without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection, based on the message.

[0008] In a fifth aspect, an apparatus is provided, comprising: means for determining in a first terminal device that user plane (UP) traffic is communicated between a first terminal device and a second terminal device without confidentiality protection, means for determining that UP traffic is communicated between the first terminal device and the second terminal device without integrity protection or with partial integrity protection, means for transmitting a message to the second terminal device indicating that UP traffic is communicated without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection, and means for communicating UP traffic between the first terminal device and the second terminal device without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection.

[0009] In a sixth aspect, an apparatus is provided, comprising: means for receiving a message from a first terminal device at a second terminal device indicating that user plane (UP) traffic is communicated between a first terminal device and a second terminal device without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection, and means for communicating UP traffic between the first terminal device and the second terminal device without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection, based on the message.

[0010] In a seventh aspect, there is provided a computer readable medium comprising program instructions which, when executed by at least one processor, cause an apparatus to perform at least a method according to the third or fourth aspects.

[0011] It should be understood that the summary section is not intended to identify key features or essential features of exemplary embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become readily apparent through the following description. [Brief description of the drawings]

[0012] Some exemplary embodiments will now be described with reference to the accompanying drawings. [Figure 1] FIG. 1 illustrates an example communication network in which example embodiments of the present disclosure may be implemented. [Diagram 2] FIG. 2 shows a high level procedure for emergency services in a UE-network relay. [Diagram 3] FIG. 3 illustrates the use of the encryption algorithm NEA to encrypt a plaintext by applying a keystream using bitwise binary addition of the plaintext and the keystream. [Figure 4] FIG. 4 illustrates the use of the integrity algorithm NIA to authenticate the integrity of a message. [Diagram 5] FIG. 5 illustrates a signaling chart illustrating a process of handling UP traffic for an emergency case according to some example embodiments of the present disclosure. [Figure 6] FIG. 6 illustrates a signaling chart illustrating an example implementation of a process for handling UP traffic for emergency cases, according to some example embodiments of the present disclosure. [Figure 7] FIG. 7 illustrates a signaling chart illustrating an example implementation of a process for handling UP traffic for emergency cases, according to some example embodiments of the present disclosure. [Figure 8] FIG. 8 illustrates a signaling chart illustrating an example implementation of a process for handling UP traffic for emergency cases, according to some example embodiments of the present disclosure. [Figure 9] FIG. 9 illustrates a flowchart of a method implemented in a first terminal device according to some example embodiments of the present disclosure. [Figure 10] FIG. 10 illustrates a flowchart of a method implemented in a second terminal device according to some example embodiments of the present disclosure. [Figure 11] FIG. 11 illustrates a simplified block diagram of an apparatus suitable for implementing exemplary embodiments of the present disclosure. [Figure 12] FIG. 12 illustrates a block diagram of an exemplary computer-readable medium in accordance with some exemplary embodiments of the present disclosure.

[0013] Throughout the drawings, the same or similar reference numbers represent the same or similar elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The principles of the present disclosure will now be described with reference to some exemplary embodiments. It should be understood that the exemplary embodiments are described for illustrative purposes only, to help those skilled in the art understand and implement the present disclosure, and do not imply any limitations on the scope of the present disclosure. The present disclosure described herein can be implemented in various ways other than those described below.

[0015] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0016] References in this disclosure to "one embodiment," "embodiment," "exemplary embodiment," and the like indicate that the embodiment being described may include a particular feature, structure, or feature, but not all embodiments need to include that particular feature, structure, or feature. Moreover, such phrases do not necessarily refer to the same embodiment. Moreover, when a particular feature, structure, or feature is described in connection with an exemplary embodiment, it is submitted that it is within the knowledge of one of ordinary skill in the art to affect that feature, structure, or feature in connection with other exemplary embodiments, whether or not explicitly described.

[0017] Terms such as "first" and "second" may be used herein to describe various elements, but it should be understood that such elements should not be limited by such terms. Such terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of the exemplary embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the listed items.

[0018] The terms used herein are merely for the purpose of describing certain exemplary embodiments and are not intended to limit the exemplary embodiments. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that as used herein, the terms "comprises," "comprising," "has," "having," "includes," and / or "including" specify the presence of stated features, elements, and / or components, etc., but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0019] As used herein, the term "circuitry" may refer to one or more or all of the following: (a) hardware-only circuitry implementations (e.g., implementations with only analog and / or digital circuitry); (b) A combination of hardware circuitry and software, such as (where applicable) (i) any combination of analog and / or digital hardware circuitry and software / firmware; (ii) any portion of a hardware processor having software (including a digital signal processor), software, and memory that cooperate to cause a device, such as a mobile phone or a server, to perform various functions; and (c) A hardware circuit and / or processor, such as a microprocessor or part of a microprocessor, that requires software (e.g., firmware) for its operation, but the software may not be present if it is not necessary for its operation.

[0020] This definition of circuitry applies to all uses of the term in this application, including any claims. As a further example, the term circuitry as used herein also encompasses merely a hardware circuit or processor (or processors), or a portion of a hardware circuit or processor, as well as its (or their) accompanying software and / or firmware implementations. The term circuitry also encompasses, for example, a baseband or processor integrated circuit for a mobile device, or similar integrated circuit in a server, cellular network device, or other computing or network device, as applicable to a particular claim element.

[0021] The term "communication network" as used herein refers to a network conforming to any suitable communication standard, such as, for example, a fifth generation (5G) system, Long Term Evolution (LTE), LTE Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. Furthermore, communication between terminal devices and network devices in the communication network may be performed according to any suitable generation of communication protocols, including, but not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) New Radio (NR) communication protocols, and / or any other protocols currently known or developed in the future. Exemplary embodiments of the present disclosure may be applied in various communication systems. Given the rapid development of communication, there may of course be future types of communication technologies and systems in which the present disclosure may be embodied. It should not be considered as limiting the scope of the present disclosure to only the aforementioned systems.

[0022] The term "network device" as used herein refers to a node in a communication network through which a terminal device accesses the network and receives services therefrom. Depending on the terminology and technology applied, the network device may refer to a base station (BS) or an access point (AP), e.g., a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), a NR next generation Node B (gNB), a remote radio unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, a low power node, e.g., a femto, a pico, etc. The RAN split architecture comprises a gNB-CU (aggregation unit, hosted RRC, SDAP, and PDCP) that controls multiple gNB-DUs (distribution units, hosted RLC, MAC, and PHY).

[0023] The term "terminal" may refer to any end device capable of wireless communication. By way of example and not limitation, a terminal may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). Terminal devices may include, but are not limited to, mobile phones, cellular phones, smartphones, voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded equipment (LEE), laptop mounted equipment (LME), USB dongles, smart devices, wireless customer premises equipment (CPE), Internet of Things (IoT) devices, watches or other wearables, head mounted displays (HMD), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronics devices, devices operating in commercial and / or industrial wireless networks, and the like. In the following description, the terms "terminal device", "communication device", "terminal", "user equipment", and "UE" may be used interchangeably.

[0024] In various exemplary embodiments, the functions described herein may be performed in fixed and / or wireless network nodes, while in other exemplary embodiments, the functions may be implemented in a user equipment device (such as a mobile phone, tablet computer, laptop computer, desktop computer, mobile IoT device, or fixed IoT device), which may comprise corresponding functions, for example, as described in connection with the fixed and / or wireless network nodes, as appropriate. The user equipment device may be user equipment and / or a control device, such as a chipset or processor, configured to control the user equipment when installed in the user equipment. Examples of such functions include a bootstrap server function and / or a home subscriber server, which may be implemented in the user equipment device by providing the user equipment device with software configured to cause the user equipment device to execute from the perspective of the function / node.

[0025] 1 illustrates an exemplary communication environment 100 in which an exemplary embodiment of the present disclosure may be implemented. The environment 100 may include a first terminal device 110, a second terminal device 120, a next-generation radio access network (NG-RAN) 130, and a 5G core network (5GC) 140.

[0026] It should be understood that the number of devices is merely for ease of understanding and does not imply any limitation. Communication environment 100 may include any suitable number or type of devices configured to implement embodiments of the present disclosure.

[0027] Communications in the communication environment 100 may be implemented according to any suitable communications protocol, including, but not limited to, first generation (1G), second generation (2G), third generation (3G), fourth generation (4G), fifth generation (5G), or future sixth generation (6G) wireless local network communications protocols, such as cellular communications protocols related to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 and the like, and / or any other protocols now known or developed in the future. Further, the communications may utilize any suitable wireless communication technology, including, but not limited to, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), frequency division duplex (FDD), time division duplex (TDD), multiple-input multiple-output (MIMO), orthogonal frequency division multiplexing (OFDM), discrete Fourier transform spread OFDM (DFT-s-OFDM), and / or any other technology now known or developed in the future.

[0028] In some exemplary embodiments, the communication environment 100 may support proximity-based service (ProSe) features, such as 5G ProSe, 4G ProSe, etc. Hereinafter, exemplary embodiments of the present disclosure will be described by taking 5G ProSe as an example. However, the present disclosure may be applied to 4G ProSe or any future ProSe.

[0029] 5G ProSe functionality may include 5G ProSe direct discovery, 5G ProSe direct communication, and 5G ProSe UE-to-network (U2N) relay.

[0030] In a 5G ProSe UE-to-network relay function, the second terminal device 120 may connect to the first terminal device 110 via a PC5 interface using 5G ProSe direct communication to communicate with the 5GC 140 via the first terminal device 110 and the NG-RAN 130. In this regard, the second terminal device 120 may be referred to as a remote terminal device 120 or a remote user equipment (UE) 120, and the first terminal device 110 may be referred to as a UE-to-network (U2N) relay or a relay UE 120.

[0031] The UE-network relay function of 5G ProSe may support emergency services in UE-network relay. In 3GPP® Technical Report (TR) 23.700-33, main issue #7 is about emergency support for UE-network relay. According to 3GPP® Technical Specification (TS) 22.101, emergency services are defined as national-authority services, and it is up to the national authorities to decide whether the network should accept emergency requests, for example, only for valid UEs or for UEs without a Subscriber Identity Module (SIM), Universal Subscriber Identity Module (USIM), or International Subscriber Identity Module (ISIM).

[0032] In 5G ProSe UE-network relay, it means that when there is an emergency request from a remote UE, the relay UE needs to take on the role of emergency services for the remote UE.

[0033] A remote UE without a USIM inserted may need to initiate emergency services with the network at the PC5 interface via a UE-Network Relay at Layer 3. The remote UE may only discover a UE-Network Relay that indicates the emergency Relay Service Code (RSC) in clear text, and is not able to establish a secure PC5 link with the UE-Network Relay.

[0034] Based on operator policy, the relay UE needs to support establishing PC5 communication for emergency services with or without PC5 security.

[0035] If the remote UE cannot be properly identified and establish PC5 security with the relay UE (if required), emergency services cannot be performed.

[0036] The 5G system shall support the establishment of PC5 communications for emergency services in UE-to-network relays with or without PC5 security.

[0037] TR33.740 proposes solution #27 to support emergency services in Layer 3 (L3) UE-network relay.

[0038] The solution addresses key issue #6 Support for emergency services in UE-network relay The solution addresses L3 UE-network relay

[0039] According to solution #27, in a 5G ProSe UE-network relay, when there is an emergency request from a remote UE, the relay UE assumes the role of emergency services for the remote UE. It is assumed that the relay UE obtains the rules on emergency services and associated operator policies from the serving PLMN of the relay UE.

[0040] Based on rules and operator policies, the relay UE supports establishing PC5 communications for emergency services to authenticated remote UEs (e.g., remote UEs that have a USIM and have been properly authenticated by the User Plane (UP) or Control Plane (CP) based on security procedures) or to unauthenticated remote UEs (e.g., remote UEs that do not have a USIM or for which authentication cannot be completed for any reason).

[0041] Based on regulations and operator policies, emergency RSC and PC5 link establishment announcement and discovery may be performed without security protection, for example, for remote UEs that have neither a USIM nor pre-configured discovery security material.

[0042] In remote UE reports for emergency services, the remote user identity, i.e., the control plane ProSe remote user key / user plane ProSe remote user key (CP-PRUK / UP-PRUK) ID, is used as the UE ID for authenticated remote UEs. In case of unauthenticated remote UEs, the Permanent Equipment Identifier (PEI) is used to identify the UE in remote UE reports.

[0043] A 5G ProSe enabled UE acting as a relay is expected to have a USIM and be registered to a PLMN in case of emergency services.

[0044] Figure 2 shows a high-level procedure of emergency services in a UE-network relay. It should be understood that for brevity, 5GC network functions (NFs) and internal signaling are not described in detail here.

[0045] 2, at 200a, a 5G ProSe UE-network relay 210 is provided with discovery security material as described in TS 33.503. Based on regulations and operator policies, there may or may not be discovery security material provided for emergency RSC.

[0046] In 200b, the 5G ProSe remote UE 220 is provided with discovery security material, as described in TS33.503, and the 5G ProSe remote UE 220 obtains a UP-PRUK and a UP-PRUK ID for a UP-based security method from the network. Based on regulations and operator policies, there may or may not be discovery security material provided for emergency RSC.

[0047] If the 5G ProSe remote UE 220 is USIM-less, step 200b is skipped. The emergency RSC and discovery security material, if present, are configured locally in the 5G ProSe remote UE 220.

[0048] At 201, a discovery procedure for emergency RSC is performed between a 5G ProSe remote UE 220 and a 5G ProSe UE-to-network relay 210 using discovery parameters and discovery security material as described in TS 33.503.

[0049] Based on regulations and operator policies, emergency RSC announcements and discovery may occur without security protection.

[0050] If the 5G ProSe remote UE 220 has a USIM, in 202, the 5G ProSe remote UE 220 receives a CP-PRUK / UP-PRUK ID or a encrypted subscriber identity (SUCI), an emergency RSC, and a K NRP Send a direct communication request (DCR) including a fresh parameter 1 to the 5G ProSe UE-network relay 210. The message may further include the PEI of the 5G ProSe remote UE 220.

[0051] If the 5G ProSe remote UE 220 is USIM-less, the 5G ProSe remote UE 220 sends a direct communication request including the PEI and emergency RSC to the 5G ProSe UE-network relay 210.

[0052] If a CP-PRUK / UP-PRUK ID or SUCI is received, at 203a and 203b, the 5G ProSe UE-network relay 210 performs UP or CP based security procedures as described in TS 33.503.

[0053] If only the PEI and Emergency RSC are received, the 5G ProSe UE-network relay 210 skips steps 203a and 203b if regulations and operator policies allow.

[0054] If steps 203a and 203b are successful, then in 204a, the 5G ProSe UE-network relay 210 performs a Security Mode Command procedure directly to the 5G ProSe remote UE 220 as described in TS 33.503.

[0055] At 204b, the 5G ProSe remote UE 220 sends a direct security mode complete message to the 5G ProSe UE-network relay 210.

[0056] If steps 203a and 203b fail or are skipped, e.g., if the 5G ProSe remote UE 220 is USIM-less, the 5G ProSe UE-network relay 210 performs a direct security mode command procedure with null encryption and integrity protection if regulations and operator policies allow.

[0057] If the 5G ProSe remote UE 220 is not successfully authenticated via a UP or CP based security procedure and a PEI is not received from the direct communication request, at 205a, the 5G ProSe UE-to-network relay 210 sends a remote identification request to the 5G ProSe remote UE 220 to obtain a PEI based on rules and operator policies.

[0058] At 205b, the 5G ProSe remote UE 220 sends a remote identity response comprising the PEI to the 5G ProSe UE-network relay 210.

[0059] At 206, the 5G ProSe UE-network relay 210 sends a direct communication accept message to the 5G ProSe remote UE 220 to complete the PC5 connection establishment procedure for the emergency service.

[0060] At 207, when the 5G ProSe Layer 3 UE-network relay 210 sends a remote UE report to the 5GC 230 for emergency RSC, the 5G ProSe Layer 3 UE-network relay 210 includes the remote user ID, i.e., CP-PRUK / UP-PRUK ID, if the UP or CP based security procedure is successful. Otherwise, the 5G ProSe Layer 3 UE-network relay 210 includes the PEI of the 5G ProSe remote UE 220 in the remote UE report.

[0061] It should be noted that protection of UP traffic between the 5G ProSe remote UE 220 and the 5G ProSe Layer 3 UE-network relay 210 in emergency cases needs to be addressed.

[0062] Figure 3 illustrates the use of the encryption algorithm NEA to encrypt a plaintext by applying a keystream using a bitwise binary addition of the plaintext and the keystream. As shown in Figure 3, the input parameters to the encryption algorithm are a 128-bit encryption key named KEY, a 32-bit COUNT, a 5-bit bearer identity BEARER, a 1-bit transmission direction (i.e., DIRECTION), and the required keystream length (i.e., LENGTH). The DIRECTION bit shall be 0 for uplink and 1 for downlink.

[0063] The receiver can generate the same keystream using the same input parameters and recover the plaintext by applying bitwise binary addition with the ciphertext.

[0064] Based on the input parameters, the algorithm generates an output keystream block KEYSTREAM, which is used to encrypt the input plaintext block PLAINTEXT to generate an output ciphertext block CIPHERTEXT.

[0065] The input parameter LENGTH shall only affect the length of the KEYSTREAM BLOCK, not its actual bits.

[0066] The null encryption algorithm (NEA0) shall be implemented to generate an all-zero KEYSTREAM (see subclause D.2.1 of TS 33.501). The length of the generated KEYSTREAM shall be equal to the LENGTH input parameter. The generated KEYSTREAM does not require any other input parameters except LENGTH. Apart from this, all processing performed related to encryption shall be exactly the same as for one of the encryption algorithms specified in Appendix D of TS 33.501.

[0067] Note that NEA0 does not provide any security.

[0068] Figure 4 illustrates the use of the integrity algorithm NIA to authenticate the integrity of a message. As shown in Figure 4, the input parameters to the integrity algorithm are a 128-bit integrity key named KEY, a 32-bit COUNT, a 5-bit bearer identification called BEARER, 1 bit of transmission direction (i.e., DIRECTION), and the message itself (i.e., MESSAGE). The DIRECTION bit shall be 0 for uplink and 1 for downlink. The length in bits of MESSAGE is LENGTH.

[0069] Based on these input parameters, the sender uses the integrity algorithm NIA to calculate a 32-bit message authentication code (Message Authentication Code-Integrity (MAC-I) or NAS-MAC). The message authentication code is then appended to the message when it is transmitted. For the integrity protection algorithm, the receiver verifies the data integrity of the message by calculating the expected message authentication code (Expected Message Authentication Code-Integrity (XMAC)-I or XNAS-MAC) in the received message in the same way that the sender calculated the sender's message authentication code in the transmitted message and comparing it with the received message authentication code, i.e., MAC-I / NAS-MAC. It should be understood that NAS-MAC and XNAS-MAC are NAS (Non-Access Stratum) layer generated message authentication code and expected message authentication code, respectively. It is generated by the mobile equipment (ME) and the access and mobility management function (AMF) depending on the data packet or control signal direction.

[0070] The null integrity algorithm (NIA0) shall be implemented to generate 32-bit MAC-I / NAS-MAC and XMAC-I / XNAS-MAC of all zeros (see subclause D.3.1 of TS 33.501). If NIA0 is activated, replay protection shall not be activated. All processing related to integrity (except replay protection) shall be exactly the same as for any of the integrity algorithms specified in this annex, except that the receiver does not verify the received MAC. Note that replay protection is mentioned because it is related to integrity.

[0071] NIA0 shall not be used for Signalling Radio Bearers (SRBs) except for unauthenticated emergency sessions for unauthenticated UEs in Restricted Service Mode (LSM).

[0072] NIA0 shall not be used for Data Radio Bearers (DRBs).

[0073] A UE with a 2G SIM is considered to be an LSM in NR.

[0074] It should be noted that the integrity algorithm NIA0 does not provide any security.

[0075] As mentioned above, the immediate support for UE-network relay is studied and concluded in TR 23.700-33. The corresponding security key issues (KI) are addressed in TR 33.740, and solutions for security KI are proposed in the same TR.

[0076] However, this solution only includes a method to transfer control plane (CP) traffic for emergency relay service. Specifically, null encryption and null integrity are used to protect the direct security mode command procedure. There is no solution to handle user plane (UP) traffic for emergency cases. Therefore, it is necessary to study the protection of UP traffic between 5G ProSe remote UE and 5G ProSe Layer 3 UE-to-network relay in emergency cases.

[0077] In addition, according to TS33.501, Appendix D, NIA0 shall not be used for DRBs. Therefore, a simple solution such as the known CP traffic protection solution using the null integrity algorithm may not work for handling UP traffic in emergency cases.

[0078] The present disclosure provides a solution for handling UP traffic for emergency cases. According to the solution, a first terminal device determines that UP traffic is communicated between the first terminal device and the second terminal device without confidentiality protection, and determines that UP traffic is communicated between the first terminal device and the second terminal device without integrity protection or with partial integrity protection. In this way, UP traffic can be communicated without confidentiality protection or without integrity protection, or with partial integrity protection without confidentiality protection.

[0079] The principle of the present disclosure will be described below with reference to FIGS.

[0080] 5 shows a signaling chart illustrating a process 500 for processing UP traffic for an emergency case according to some exemplary embodiments of the present disclosure. For illustrative purposes, the process 500 is described with reference to FIG. 1. The process 500 may include the first terminal device 110 and the second terminal device 120 in FIG. 1.

[0081] As shown in FIG. 5, the first terminal device 110 determines (510) that UP traffic is to be communicated between the first terminal device 110 and the second terminal device 120 without confidentiality protection.

[0082] The first terminal device 110 determines (520) that UP traffic is communicated between the first terminal device 110 and the second terminal device 120 without integrity protection or with partial integrity protection.

[0083] The first terminal device 110 then sends (530) a message to the second terminal device 120. The message indicates that the UP traffic is to be communicated without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection.

[0084] The first terminal device 110 then communicates (540) UP traffic between the first terminal device 110 and the second terminal device 120 without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection.

[0085] In some example embodiments, the first terminal device 110 may determine that the UP traffic is communicated without confidentiality protection based on at least one of the following: at least one local policy, Emergency RSC received from the second terminal device 120; at least one UP security policy received from the second terminal device 120; The functionality of the first terminal device 110, or Functions of the second terminal device 120.

[0086] In some example embodiments, the first terminal device 110 may determine that the UP traffic is communicated without integrity protection or with partial integrity protection based on at least one of the following: at least one local policy, Emergency RSC received from the second terminal device 120; at least one UP security policy received from the second terminal device 120; The functionality of the first terminal device 110, or Functions of the second terminal device 120.

[0087] Some example implementations of the process 500 are described below with reference to FIGS.

[0088] In the exemplary implementation of Figures 6 to 8, the U2N relay and the remote UE are respectively taken as examples of the first terminal device 110 and the second terminal device 120. The remote UE 120 does not have a USIM. A similar process may be applicable to the remote UE 120 that has a USIM but fails authentication and authorization for the general ProSe U2N relay service.

[0089] 6 shows a signaling chart illustrating a process 600 for processing UP traffic for an emergency case according to some exemplary embodiments of the present disclosure. The process 600 may be regarded as an exemplary implementation of the process 500. For illustrative purposes, the process 600 is described with reference to FIG. 1. The process 600 may include the first terminal device 110, the second terminal device 120, and the 5GC 140 in FIG. 1.

[0090] In 601, preparation for 5G ProSe UE-network relay communication is performed between the first terminal device 110, the second terminal device 120, and the 5GC 140. The first terminal device 110 and the second terminal device are authenticated and authorized, and the first terminal device 110 and the second terminal device are possibly provided with security information during the preparation phase.

[0091] In some example embodiments, steps 0a to 1b of FIG. 6.3.3.2.2-1 for a PC5 security establishment procedure for 5G ProSe UE-network relay communications in the user plane from TS33.503 or steps 0a to 0b of FIG. 6.3.3.3.2-1 for a PC5 security establishment procedure for 5G ProSe UE-network relay communications in the control plane may be performed.

[0092] The remote UE 120 or U2N relay 110 initiates a discovery procedure (602) using either the Model A or Model B method as specified in TS 23.304 clauses 6.3.1.2 or 6.3.1.3, respectively.

[0093] After discovery of the U2N relay 110, the USIM-less remote UE 120 triggers (603) emergency services.

[0094] The remote UE 120 sends a direct communication request message with the PEI and emergency RSC to the U2N relay 110 (604).

[0095] The U2N relay 110 sends (605) a direct security mode command to the remote UE 120 to establish a secure PC5 link, in particular to protect the PC5 signaling.

[0096] The remote UE 120 responds (606) with a direct security mode complete message to the U2N relay 110. The direct security mode complete message comprises at least one UP security policy for the emergency RSC.

[0097] Based on the at least one local policy, the emergency RSC received from the remote UE 120 and the at least one UP security policy for the emergency RSC, and the capabilities of the remote UE 120 and the U2N relay 110, the U2N relay 110 determines (607) that a confidentiality protection algorithm is not applied to the UP traffic. In this way, the cost of performing an encryption or decryption algorithm can be reduced.

[0098] For example, the UP security policy from the remote UE 120 may indicate that security protection for UP traffic is not required. The local policy of the relay UE 110 may indicate that emergency services are supported even if the remote UE 120 does not have a USIM or a remote UE with a USIM fails authentication and authorization for general ProSe U2N relay service. Based on the UP security policy from the remote UE 120 and the local policy of the relay UE 110, the U2N relay 110 determines that a confidentiality protection algorithm is not applied to the UP traffic. It should be understood that the U2N relay 110 may determine that a confidentiality protection algorithm is not applied to the UP traffic based on any other UP security policy or the local policy of the relay UE 110.

[0099] Based on at least one local policy, the emergency RSC received from the remote UE 120 and at least one UP security policy for the emergency RSC, and the capabilities of the remote UE 120 and the U2N relay 110, the U2N relay 110 determines (608) that an integrity protection algorithm is not applied to the UP traffic. NRP The -sess ID is ignored. In this way, the bandwidth for transmitting "fake" MACs can be reduced, which follows the rule defined in TS 33.501 that "NIA0 shall not be used for Data Radio Bearers (DRBs)".

[0100] For example, the UP security policy from the remote UE 120 may indicate that security protection for UP traffic is not required. The local policy of the relay UE 110 may indicate that emergency services are supported even if the remote UE 120 does not have a USIM or a remote UE with a USIM fails authentication and authorization for general ProSe U2N relay service. Based on the UP security policy from the remote UE 120 and the local policy of the relay UE 110, the U2N relay 110 determines that the integrity protection algorithm is not applied to the UP traffic. It should be understood that the U2N relay 110 may determine that the integrity protection algorithm is not applied to the UP traffic based on any other UP security policy or the local policy of the relay UE 110.

[0101] The U2N relay 110 sends a direct communication accept message to the remote UE 120 (609). The direct communication accept message may indicate that the UP traffic is communicated without confidentiality or integrity protection. For example, the direct communication accept message indicates that no confidentiality or integrity protection algorithms are applied to the UP traffic. For example, the Chosen_algos information element (IE) in the direct communication accept message may be empty.

[0102] Upon receiving the direct communication accept message, the remote UE 120 determines (610) not to protect UP traffic for emergency services because the security algorithm is not selected by the U2N relay 110.

[0103] The remote UE 120 and the U2N relay 110 communicate UP traffic in plain text without any MAC appended over the PC5 link (611).

[0104] 7 shows a signaling chart illustrating a process 700 for processing UP traffic for an emergency case according to some exemplary embodiments of the present disclosure. The process 700 may be regarded as an exemplary implementation of the process 500. For illustrative purposes, the process 700 is described with reference to FIG. 1. The process 700 may include the first terminal device 110, the second terminal device 120, and the 5GC 140 in FIG. 1.

[0105] The operations at 601-606 in process 700 are similar to those in process 600. Therefore, for the sake of brevity, details of these operations are omitted.

[0106] The operations in 701 - 705 in process 700 are different from the operations in process 600 .

[0107] Specifically, based on at least one local policy, the emergency RSC received from the remote UE 120 and at least one UP security policy for the emergency RSC, and the capabilities of the remote UE 120 and the U2N relay 110, the U2N relay 110 determines (701) that a null confidentiality protection algorithm is applied to the UP traffic.

[0108] For example, the UP security policy from the remote UE 120 may indicate that security protection for UP traffic is not required. The local policy of the relay UE 110 may indicate that emergency services are supported even if the remote UE 120 does not have a USIM or a remote UE with a USIM fails authentication and authorization for general ProSe U2N relay service. Based on the UP security policy from the remote UE 120 and the local policy of the relay UE 110, the U2N relay 110 determines that a null confidentiality protection algorithm is applied to the UP traffic. It should be understood that the U2N relay 110 may determine that a null confidentiality protection algorithm is applied to the UP traffic based on any other UP security policy or the local policy of the relay UE 110.

[0109] Based on at least one local policy, the emergency RSC received from the remote UE 120 and at least one UP security policy for the emergency RSC, and the capabilities of the remote UE 120 and the U2N relay 110, the U2N relay 110 determines (702) that a null integrity protection algorithm is applied to the UP traffic.

[0110] For example, the UP security policy from the remote UE 120 may indicate that security protection for UP traffic is not required. The local policy of the relay UE 110 may indicate that emergency services are supported even if the remote UE 120 does not have a USIM or a remote UE with a USIM fails authentication and authorization for general ProSe U2N relay service. Based on the UP security policy from the remote UE 120 and the local policy of the relay UE 110, the U2N relay 110 determines that a null integrity protection algorithm is applied to the UP traffic. It should be understood that the U2N relay 110 may determine that a null integrity protection algorithm is applied to the UP traffic based on any other UP security policy or the local policy of the relay UE 110.

[0111] The U2N relay 110 sends a direct communication accept message to the remote UE 120 (703). The direct communication accept message may indicate that the UP traffic is communicated without confidentiality or integrity protection. For example, the direct communication accept message may indicate selected null security algorithms in a Chosen_algos IE. The selected null security algorithms include a null confidentiality protection algorithm and a null integrity protection algorithm.

[0112] Upon receiving the direct communication accept message, the remote UE 120 determines to use the null confidentiality algorithm and the null integrity algorithm for UP traffic for emergency services as the null security algorithm selected by the U2N relay 110 (704).

[0113] The remote UE 120 and the U2N relay 110 each generate ciphertext (i.e., UP traffic) using a KEYSTREAM of all zeros.

[0114] The remote UE 120 and the U2N relay 110 communicate 705 the UP traffic in ciphertext over the PC5 link using an all-zero MAC, also referred to as the first MAC.

[0115] 8 shows a signaling chart illustrating a process 800 of processing UP traffic for an emergency case according to some exemplary embodiments of the present disclosure. The process 800 may be regarded as an exemplary implementation of the process 500. For illustrative purposes, the process 800 is described with reference to FIG. 1. The process 800 may include the first terminal device 110, the second terminal device 120, and the 5GC 140 in FIG. 1.

[0116] The operations in 601-606 in process 800 are similar to those in process 600. The operation in 801 in process 800 is similar to the operation in 701 in process 700. Therefore, details of these operations are omitted for the sake of brevity.

[0117] The operations at 802-805 in process 800 differ from the operations in processes 600 and 700.

[0118] Specifically, based on at least one local policy, the emergency RSC received from the remote UE 120 and at least one UP security policy for the emergency RSC, and the capabilities of the remote UE 120 and the U2N relay 110, the U2N relay 110 determines (802) that a non-null integrity protection algorithm is applied to the UP traffic.

[0119] For example, the UP security policy from the remote UE 120 may indicate that integrity protection for UP traffic is preferred or required. The local policy of the relay UE 110 may indicate that emergency services are supported even if the remote UE 120 does not have a USIM or a remote UE with a USIM fails authentication and authorization for general ProSe U2N relay services. Based on the UP security policy from the remote UE 120 and the local policy of the relay UE 110, the U2N relay 110 determines that a non-null integrity protection algorithm is applied to the UP traffic. It should be understood that the U2N relay 110 may determine that a non-null integrity protection algorithm is applied to the UP traffic based on any other UP security policy or the local policy of the relay UE 110.

[0120] In some exemplary embodiments, examples of non-null integrity protection algorithms may include, but are not limited to, 128-NIA1, 128-NIA2, or 128-NIA3.

[0121] The U2N relay 110 sends a direct communication acknowledgement message to the remote UE 120 (803). The direct communication acknowledgement message may indicate that the UP traffic is communicated without confidentiality protection and with partial integrity protection. For example, the direct communication acknowledgement message may indicate a null confidentiality protection algorithm for the UP traffic and a non-null integrity protection algorithm for the UP traffic in the Chosen_algos IE. By using a non-null integrity protection algorithm for the UP traffic, the integrity of the UP traffic may be protected to some extent. For example, this may prevent data loss for unintentional unstable radio conditions.

[0122] Upon receiving the direct communication accept message, the remote UE 120 decides to use a null confidentiality algorithm and a non-null integrity algorithm for UP traffic for emergency services (804).

[0123] To communicate UP traffic, the remote UE 120 and the U2N relay 110 each generate a ciphertext (i.e., UP traffic) using a KEYSTREAM of all zeros.

[0124] In addition, the remote UE 120 and the U2N relay 110 each generate a MAC based on at least one of the COUNT, a bearer identity for the UP traffic, an indication of the transmission direction of the UP traffic, an all-zero integrity key (i.e., an all-zero KEYSTREAM), or a UP message carrying the UP traffic by using a non-null integrity protection algorithm. The generated MAC is also referred to as a second MAC.

[0125] In some example embodiments, COUNT may indicate the number or order of UP messages. In addition, COUNT may be used for replay protection. For example, COUNT may be a 32-bit (Packet Data Convergence Protocol, PDCP) count.

[0126] In some example embodiments, the bearer identity for UP traffic may be a 5-bit bearer identity called BEARER.

[0127] In some example embodiments, the indication of the transmission direction of UP traffic may be a one-bit transmission direction indication: 0 for uplink and 1 for downlink.

[0128] In some example embodiments, the all-zero integrity key may be a 128-bit all-zero integrity key.

[0129] The remote UE 120 and the U2N relay 110 then communicate UP traffic in ciphertext using the generated MAC over the PC5 link (805).

[0130] In an exemplary embodiment where UP traffic is communicated with partial integrity protection, the remote UE 120 and the U2N relay 110 may each generate a third MAC based on at least one of the COUNT, the bearer identity for the UP traffic, an indication of the transmission direction of the UP traffic, or the UP message carrying the UP traffic. The remote UE 120 and the U2N relay 110 may then communicate the UP traffic using the third MAC. Note that in the exemplary embodiment, the U2N relay 110 does not need to determine a 3GPP-defined algorithm because there is no key. In the exemplary embodiment, the third MAC may be a Message Digest Algorithm 5 (MD5) or a Secure Hash Algorithm 256-bit (SHA-256). MD5 uses a hash function to generate a 128-bit hash value. The output of SHA-256 is 256 bits long.

[0131] In some exemplary embodiments, the first terminal device 110 may determine that the UP traffic is communicated without confidentiality protection by determining that a null confidentiality protection algorithm is applied to the UP traffic. In the exemplary embodiments, the first terminal device 110 may determine that the UP traffic is communicated without integrity protection by determining that no integrity protection algorithm is applied to the UP traffic. In the exemplary embodiments, the first terminal device 110 may encrypt the UP traffic with an all-zero keystream by using the null confidentiality protection algorithm. The first terminal device 110 may then communicate the UP traffic in ciphertext without a MAC.

[0132] In some exemplary embodiments, the first terminal device 110 may determine that the UP traffic is communicated without confidentiality protection by determining that no confidentiality protection algorithm is applied to the UP traffic. In the exemplary embodiments, the first terminal device 110 may determine that the UP traffic is communicated without integrity protection by determining that a null integrity protection algorithm is applied to the UP traffic. In the exemplary embodiments, the first terminal device 110 may generate an all-zero first MAC by using the null integrity protection algorithm and communicate the UP traffic in plaintext using the all-zero first MAC.

[0133] In some exemplary embodiments, the first terminal device 110 may determine that the UP traffic is communicated without confidentiality protection by determining that no confidentiality protection algorithm is applied to the UP traffic. In the exemplary embodiment, the first terminal device 110 may determine that the UP traffic is communicated with partial integrity protection by determining a non-null integrity protection algorithm for the UP traffic based on the capabilities of the first terminal device and the second terminal device. In the exemplary embodiment, the first terminal device 110 may generate a second MAC by using the non-null integrity protection algorithm. The second MAC may be generated based on at least one of a COUNT, an identification of a bearer for the UP traffic, an indication of a transmission direction of the UP traffic, an all-zero integrity key, or a UP message carrying the UP traffic. The first terminal device 110 may then communicate the UP traffic in plaintext using the second MAC.

[0134] 9 illustrates a flowchart of an example method 900 implemented in a first terminal device, according to some example embodiments of the present disclosure. For purposes of explanation, the method 900 is described from the perspective of the first terminal device 110 with respect to FIG.

[0135] In block 910, the first terminal device 110 determines that UP traffic is communicated between the first terminal device 110 and the second terminal device 120 without confidentiality protection.

[0136] In block 920, the first terminal device 110 determines that UP traffic is communicated between the first terminal device 110 and the second terminal device 120 without integrity protection or with partial integrity protection.

[0137] In block 930, the first terminal device 110 sends a message to the second terminal device 120. The message indicates that UP traffic is to be communicated without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection.

[0138] In block 940, the first terminal device 110 communicates UP traffic between the first terminal device 110 and the second terminal device 120 without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection.

[0139] In some example embodiments, determining that the UP traffic is communicated without confidentiality protection may include determining that the UP traffic is communicated without confidentiality protection based on at least one of the following: at least one local policy, Emergency RSC received from the second terminal device 120; at least one UP security policy received from the second terminal device 120; The functionality of the first terminal device 110, or Functions of the second terminal device 120.

[0140] In some example embodiments, determining that the UP traffic is communicated without or with partial integrity protection may include determining that the UP traffic is communicated without or with partial integrity protection based on at least one of the following: at least one local policy, Emergency RSC received from the second terminal device 120; at least one UP security policy received from the second terminal device 120; The functionality of the first terminal device 110, or Functions of the second terminal device 120.

[0141] In some example embodiments, determining that the UP traffic is communicated without confidentiality protection may include determining that a confidentiality protection algorithm is not applied to the UP traffic. Communicating the UP traffic may include communicating the UP traffic in plaintext.

[0142] In some example embodiments, determining that the UP traffic is to be communicated without confidentiality protection may include determining that a null confidentiality protection algorithm is to be applied to the UP traffic. Communicating the UP traffic may include encrypting the UP traffic with an all-zero keystream by using the null confidentiality protection algorithm.

[0143] In some example embodiments, determining that the UP traffic is to be communicated without integrity protection may include determining that an integrity protection algorithm is not applied to the UP traffic. Communicating the UP traffic may include communicating the UP traffic without a MAC.

[0144] In some example embodiments, determining that the UP traffic is to be communicated without integrity protection may include determining that a null integrity protection algorithm is applied to the UP traffic. Communicating the UP traffic may include generating a first MAC of all zeros by using the null integrity protection algorithm, and communicating the UP traffic with the first MAC.

[0145] In some example embodiments, determining that the UP traffic is communicated with partial integrity protection may include determining a non-null integrity protection algorithm for the UP traffic based on capabilities of the first terminal device 110 and the second terminal device 120. Communicating the UP traffic may include generating a second MAC based on at least one of a COUNT, an identification of a bearer for the UP traffic, an indication of a transmission direction of the UP traffic, an all-zero integrity key, or a UP message carrying the UP traffic by using the non-null integrity protection algorithm, and communicating the UP traffic using the second MAC.

[0146] In some example embodiments, communicating the UP traffic with partial integrity protection may include generating a third MAC based on at least one of a COUNT, an identification of a bearer for the UP traffic, an indication of a transmission direction of the UP traffic, or an UP message conveying the UP traffic, and communicating the UP traffic using the third MAC.

[0147] 10 illustrates a flowchart of an example method 1000 implemented in a second terminal device according to some example embodiments of the present disclosure. For purposes of explanation, the method 1000 is described from the perspective of the second terminal device 110 with respect to FIG.

[0148] In block 1010, the second terminal device 120 receives a message from the first terminal device 110. The message indicates that UP traffic is communicated between the first terminal device 110 and the second terminal device 120 without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection.

[0149] In block 1020, the second terminal device 120 communicates UP traffic between the first terminal device 110 and the second terminal device 120 based on the message without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection.

[0150] In some example embodiments, the message indicates that the UP traffic is communicated without confidentiality protection by indicating that a confidentiality protection algorithm is not applied to the UP traffic. Communicating the UP traffic may include communicating the UP traffic in plaintext.

[0151] In some example embodiments, the message indicates that the UP traffic is communicated without confidentiality protection by indicating a null confidentiality protection algorithm for the UP traffic. Communicating the UP traffic may include encrypting the UP traffic with an all-zero keystream.

[0152] In some example embodiments, the message indicates that the UP traffic is communicated without integrity protection by indicating that an integrity protection algorithm is not applied to the UP traffic. Communicating the UP traffic may include communicating the UP traffic without using a MAC.

[0153] In some example embodiments, the message indicates that the UP traffic is communicated without integrity protection by indicating a null integrity protection algorithm for the UP traffic. Communicating the UP traffic may include generating a first MAC of all zeros and communicating the UP traffic with the first MAC.

[0154] In some example embodiments, the message indicates that the UP traffic is communicated with partial integrity protection by indicating a non-null integrity protection algorithm for the UP traffic. Communicating the UP traffic may include generating a second MAC based on at least one of a COUNT, an identity of a bearer for the UP traffic, an indication of a transmission direction of the UP traffic, an all-zero integrity key, or a UP message carrying the UP traffic by using the non-null integrity protection algorithm, and communicating the UP traffic with the second MAC.

[0155] In some exemplary embodiments, communicating UP traffic with partial integrity protection includes generating a third MAC based on at least one of a COUNT, a bearer identification for the UP traffic, an indication of a transmission direction of the UP traffic, or an UP message conveying the UP traffic, and communicating the UP traffic using the third MAC.

[0156] In some example embodiments, the method 1000 further includes transmitting at least one UP security policy to the first terminal device 110 .

[0157] In some exemplary embodiments, an apparatus (e.g., the first terminal device 110) capable of performing any of the methods 900 may comprise means for performing each operation of the method 900. The means may be implemented in any suitable form. For example, the means may be implemented in a circuit or a software module. The apparatus may be implemented as the first terminal device 110 or may be included in the first terminal device 110. In some exemplary embodiments, the means may comprise a processor and a memory.

[0158] In some exemplary embodiments, the apparatus comprises means for determining in a first terminal device that user plane (UP) traffic is communicated between a first terminal device and a second terminal device without confidentiality protection, means for determining that UP traffic is communicated between the first terminal device and the second terminal device without integrity protection or with partial integrity protection, means for sending a message to the second terminal device indicating that the UP traffic is communicated without confidentiality or integrity protection, or with no confidentiality protection and partial integrity protection, and means for communicating UP traffic between the first terminal device and the second terminal device without confidentiality or integrity protection, or with no confidentiality protection and partial integrity protection.

[0159] In some example embodiments, the means for determining that the UP traffic is communicated without confidentiality protection may comprise means for determining that the UP traffic is communicated without confidentiality protection based on at least one of the following: at least one local policy, Emergency RSC received from a second terminal device; at least one UP security policy received from a second terminal device; The functionality of the first terminal device, or - Functions of the second terminal device.

[0160] In some example embodiments, the means for determining that the UP traffic is communicated without or with partial integrity protection may include determining that the UP traffic is communicated without or with partial integrity protection based on at least one of the following: at least one local policy, Emergency RSC received from a second terminal device; at least one UP security policy received from a second terminal device; The functionality of the first terminal device, or - Functions of the second terminal device.

[0161] In some example embodiments, the means for determining that the UP traffic is communicated without confidentiality protection may comprise means for determining that a confidentiality protection algorithm is not applied to the UP traffic. The means for communicating the UP traffic may comprise means for communicating the UP traffic in plaintext.

[0162] In some example embodiments, the means for determining that the UP traffic is communicated without confidentiality protection may comprise means for determining that a null confidentiality protection algorithm is applied to the UP traffic. The means for communicating the UP traffic may comprise means for encrypting the UP traffic with an all-zero keystream by using the null confidentiality protection algorithm.

[0163] In some example embodiments, the means for determining that the UP traffic is communicated without integrity protection may comprise means for determining that an integrity protection algorithm is not applied to the UP traffic. The means for communicating the UP traffic may comprise means for communicating the UP traffic without a MAC.

[0164] In some example embodiments, the means for determining that the UP traffic is communicated without integrity protection may comprise means for determining that a null integrity protection algorithm is applied to the UP traffic. The means for communicating the UP traffic may comprise means for generating a first MAC of all zeros by using the null integrity protection algorithm, and means for communicating the UP traffic with the first MAC.

[0165] In some example embodiments, the means for determining that the UP traffic is communicated with partial integrity protection may comprise means for determining a non-null integrity protection algorithm for the UP traffic based on capabilities of the first terminal device and the second terminal device. The means for communicating the UP traffic may comprise means for generating a second MAC based on at least one of a COUNT, an identity of a bearer for the UP traffic, an indication of a transmission direction of the UP traffic, an all-zero integrity key, or a UP message carrying the UP traffic by using the non-null integrity protection algorithm, and means for communicating the UP traffic using the second MAC.

[0166] In some example embodiments, the means for communicating UP traffic with partial integrity protection may comprise means for generating a third MAC based on at least one of a COUNT, an identification of a bearer for the UP traffic, an indication of a transmission direction of the UP traffic, or an UP message conveying the UP traffic, and means for communicating the UP traffic using the third MAC.

[0167] In some exemplary embodiments, an apparatus capable of performing any of the methods 1000 (e.g., the second terminal device 120) may comprise means for performing each operation of the method 1000. The means may be implemented in any suitable form. For example, the means may be implemented in a circuit or a software module. The apparatus may be implemented as the second terminal device 120 or may be included in the second terminal device 120. In some exemplary embodiments, the means may comprise a processor and a memory.

[0168] In some exemplary embodiments, the apparatus comprises means for receiving a message at a second terminal device from a first terminal device indicating that user plane (UP) traffic is communicated between the first terminal device and the second terminal device without confidentiality or integrity protection, or with no confidentiality protection and partial integrity protection, and means for communicating UP traffic between the first terminal device and the second terminal device without confidentiality or integrity protection, or with no confidentiality protection and partial integrity protection, based on the message.

[0169] In some example embodiments, the message indicates that the UP traffic is communicated without confidentiality protection by indicating that a confidentiality protection algorithm is not applied to the UP traffic. The means for communicating the UP traffic may comprise means for communicating the UP traffic in plaintext.

[0170] In some example embodiments, the message indicates that the UP traffic is communicated without confidentiality protection by indicating a null confidentiality protection algorithm for the UP traffic. The means for communicating the UP traffic may comprise means for encrypting the UP traffic with an all-zero keystream.

[0171] In some example embodiments, the message indicates that the UP traffic is communicated without integrity protection by indicating that an integrity protection algorithm is not applied to the UP traffic. The means for communicating the UP traffic may comprise means for communicating the UP traffic without using a MAC.

[0172] In some example embodiments, the message indicates that the UP traffic is communicated without integrity protection by indicating a null integrity protection algorithm for the UP traffic. The means for communicating the UP traffic may comprise means for generating a first MAC of all zeros and means for communicating the UP traffic with the first MAC.

[0173] In some example embodiments, the message indicates that the UP traffic is communicated with partial integrity protection by indicating a non-null integrity protection algorithm for the UP traffic. The means for communicating the UP traffic may comprise means for generating a second MAC based on at least one of a COUNT, an identity of a bearer for the UP traffic, an indication of a transmission direction of the UP traffic, an all-zero integrity key, or a UP message carrying the UP traffic by using the non-null integrity protection algorithm, and means for communicating the UP traffic with the second MAC.

[0174] In some exemplary embodiments, the means for communicating UP traffic with partial integrity protection comprises means for generating a third MAC based on at least one of a COUNT, a bearer identification for the UP traffic, an indication of a transmission direction of the UP traffic, or an UP message conveying the UP traffic, and means for communicating the UP traffic using the third MAC.

[0175] In some exemplary embodiments, the apparatus further comprises means for transmitting at least one UP security policy to the first terminal device.

[0176] It should be understood that details of the exemplary embodiments of the present disclosure described with reference to FIGS. 5-8 also apply to methods 900 and 1000.

[0177] 11 is a simplified block diagram of a device 1100 suitable for implementing an embodiment of the present disclosure. The device 1100 may be provided to implement a communication device, such as the first terminal device 110 or the second terminal device 120 as shown in FIG. As shown, the device 1100 includes one or more processors 1110, one or more memories 1120 connected to the processor 1110, and one or more communication modules 1140 connected to the processor 1110.

[0178] The communication module 1140 is for bidirectional communication. The communication module 1140 has at least one antenna to facilitate communication. The communication interface may represent any interface necessary for communication with other network elements.

[0179] The processor 1110 may be of any type suitable for a local technology network and may include, by way of non-limiting examples, one or more of a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. The device 1100 may have multiple processors, such as application specific integrated circuit chips, time-slaved to a clock that synchronizes a main processor.

[0180] The memory 1120 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 1124, electrically programmable read-only memory (EPROM), flash memory, hard disks, compact disks (CDs), digital video disks (DVDs), and other magnetic and / or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 1122 and other volatile memories that do not persist between power outages.

[0181] The computer program 1130 includes computer-executable instructions that are executed by an associated processor 1110. The program 1130 may be stored in the ROM 1124. The processor 1110 may load the program 1130 into the RAM 1122 to perform any suitable operation and processing.

[0182] The embodiments of the present disclosure may be implemented by means of a program 1130, such that the device 1100 may perform any process of the present disclosure as described with reference to Figures 1 to 10. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0183] In some exemplary embodiments, the program 1130 may be tangibly included in a computer-readable medium that may be included in the device 1100 (such as memory 1120) or other storage device accessible by the device 1100. The device 1100 may load the program 1130 from the computer-readable medium into RAM 1122 for execution. The computer-readable medium may include any type of tangible non-volatile storage, such as ROM, EPROM, flash memory, hard disk, CD, DVD, and the like. Figure 12 shows an example of a computer-readable medium 1200 in the form of a CD or DVD. The computer-readable medium stores the program 1130.

[0184] Generally, various embodiments of the present disclosure may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are shown and described as block diagrams, flow charts, or using some other graphical representations, it should be understood that the blocks, apparatus, systems, techniques, or methods described herein may be implemented in, by way of non-limiting examples, hardware, software, firmware, dedicated circuits or logic, general-purpose hardware or controller, or other computing device, or any combination thereof.

[0185] The present disclosure also provides at least one computer program product tangibly stored in a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in a program module, that execute on a target real or virtual processor in a device to perform the methods 900 and 1000 as described above with reference to FIG. 9 and FIG. 10. Generally, a program module includes routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or separated among program modules as desired in various embodiments. The machine-executable instructions for the program modules may be executed in a local device or a distributed device. In a distributed device, the program modules may be located in both local and remote storage media.

[0186] The program code for carrying out the methods of the present disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general purpose computer, a special purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the implementation of the functions / operations specified in the flowcharts and / or block diagrams. The program code may be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0187] In the context of the present disclosure, computer program code or associated data may be carried by any suitable carrier that enables a device, apparatus, or processor to perform the various processes and operations as described above. Examples of carriers include signals, computer readable media, and the like.

[0188] The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. More specific examples of the computer-readable storage medium include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0189] Furthermore, although operations are depicted in a particular order, this should not be understood as requiring that the operations be performed in the particular order or sequential order shown, or that all of the operations shown be performed, to achieve a desired result. In certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although details of certain implementation aspects are included in the above description, such details should not be construed as limitations on the scope of the disclosure, but rather should be understood as descriptions of features that may be specific to certain embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination.

[0190] Although the present disclosure has been described in terms specific to structural features or method acts, it is to be understood that the present disclosure as defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A first terminal device, At least one processor; at least one memory for storing instructions; Equipped with The instructions, when executed by the at least one processor, provide at least one of the following to the first terminal device: determining that user plane (UP) traffic is communicated between the first terminal device and a second terminal device without confidentiality protection; determining that the UP traffic is communicated between the first terminal device and the second terminal device without integrity protection or with partial integrity protection; causing the second terminal device to transmit a message indicating that the UP traffic is communicated without the confidentiality protection or the integrity protection, or without the confidentiality protection and with the partial integrity protection; communicating the UP traffic between the first terminal device and the second terminal device without the confidentiality protection or the integrity protection, or without the confidentiality protection and with the partial integrity protection; A first terminal device.

2. For the first terminal device, At least one local policy; an emergency relay service code (RSC) received from the second terminal device; at least one UP security policy received from the second terminal device; The functionality of the first terminal device, or The function of the second terminal device; determining that the UP traffic is communicated without the confidentiality protection based on at least one of: The first terminal device according to claim 1 .

3. For the first terminal device, At least one local policy; an emergency relay service code (RSC) received from the second terminal device; at least one UP security policy received from the second terminal device; The functionality of the first terminal device, or The function of the second terminal device; determining that the UP traffic is communicated without the integrity protection or with the partial integrity protection based on at least one of 3. A first terminal device according to claim 1 or 2.

4. For the first terminal device, determining that the UP traffic is communicated without the confidentiality protection by determining that a confidentiality protection algorithm is not applied to the UP traffic; For the first terminal device, communicating said UP traffic by communicating said UP traffic in plain text; A first terminal device according to any one of claims 1 to 3.

5. For the first terminal device, determining that the UP traffic is communicated without said confidentiality protection by determining that a null confidentiality protection algorithm is applied to the UP traffic; For the first terminal device, communicating said UP traffic by encrypting said UP traffic with an all-zero keystream using said null confidentiality protection algorithm; A first terminal device according to any one of claims 1 to 3.

6. For the first terminal device, determining that the UP traffic is communicated without the integrity protection by determining that an integrity protection algorithm is not applied to the UP traffic; For the first terminal device, communicating the UP traffic by communicating the UP traffic without using a message authentication code (MAC); A first terminal device according to any one of claims 1 to 5.

7. For the first terminal device, determining that the UP traffic is communicated without the integrity protection by determining that a null integrity protection algorithm is applied to the UP traffic; For the first terminal device, generating a first message authentication code (MAC) of all zeros by using the null integrity protection algorithm; and communicating the UP traffic by communicating the UP traffic using the first MAC; A first terminal device according to any one of claims 1 to 5.

8. For the first terminal device, determining that the UP traffic is communicated with the partial integrity protection by determining a non-null integrity protection algorithm for the UP traffic based on capabilities of the first terminal device and the second terminal device; For the first terminal device, generating a second message authentication code (MAC) based on at least one of a COUNT, a bearer identity for the UP traffic, an indication of a transmission direction of the UP traffic, an all-zero integrity key, or a UP message carrying the UP traffic by using the non-null integrity protection algorithm; and communicating the UP traffic using the second MAC; and communicating the UP traffic by A first terminal device according to any one of claims 1 to 5.

9. For the first terminal device, generating a third message authentication code (MAC) based on at least one of a COUNT, an identification of a bearer for the UP traffic, an indication of a transmission direction of the UP traffic, or a UP message carrying the UP traffic; and communicating the UP traffic using the third MAC; communicating the UP traffic with the partial integrity protection by A first terminal device according to any one of claims 1 to 5.

10. A second terminal device, At least one processor; at least one memory for storing instructions; Equipped with The instructions, when executed by the at least one processor, provide at least one of the following to the second terminal device: receiving a message from a first terminal device indicating that user plane (UP) traffic is communicated between the first terminal device and the second terminal device without confidentiality or integrity protection, or without the confidentiality protection and with partial integrity protection; communicating the UP traffic between the first terminal device and the second terminal device based on the message without the confidentiality protection or the integrity protection, or without the confidentiality protection and with the partial integrity protection; A second terminal device.

11. The message may include: indicating that the UP traffic is communicated without the confidentiality protection by indicating that a confidentiality protection algorithm is not applied to the UP traffic; With respect to the second terminal device, communicating said UP traffic by communicating said UP traffic in plain text; The second terminal device according to claim 10.

12. The message may include: indicating a null confidentiality protection algorithm for the UP traffic, thereby indicating that the UP traffic is communicated without the confidentiality protection; With respect to the second terminal device, communicating the UP traffic by encrypting the UP traffic with an all-zero keystream; A second terminal device according to claim 10 or 11.

13. The message may include: indicating that the UP traffic is communicated without the integrity protection by indicating that an integrity protection algorithm is not applied to the UP traffic; With respect to the second terminal device, communicating the UP traffic by communicating the UP traffic without using a message authentication code (MAC); A second terminal device according to any one of claims 10 to 12.

14. The message may include: indicating a null integrity protection algorithm for the UP traffic, thereby indicating that the UP traffic is communicated without the integrity protection; With respect to the second terminal device, generating a first message authentication code (MAC) of all zeros; and communicating the UP traffic using the first MAC; and communicating the UP traffic by A second terminal device according to any one of claims 10 to 12.

15. The message may include: indicating a non-null integrity protection algorithm for the UP traffic, thereby indicating that the UP traffic is communicated with the partial integrity protection; With respect to the second terminal device, generating a second message authentication code (MAC) based on at least one of a COUNT, a bearer identity for the UP traffic, an indication of a transmission direction of the UP traffic, an all-zero integrity key, or a UP message carrying the UP traffic by using the non-null integrity protection algorithm; and communicating the UP traffic using the second MAC; and communicating the UP traffic by A second terminal device according to any one of claims 10 to 12.

16. With respect to the second terminal device, generating a third message authentication code (MAC) based on at least one of a COUNT, an identification of a bearer for the UP traffic, an indication of a transmission direction of the UP traffic, or a UP message carrying the UP traffic; and communicating the UP traffic using the third MAC; communicating the UP traffic with the partial integrity protection by A second terminal device according to any one of claims 10 to 12.

17. The second terminal device further transmitting at least one UP security policy to the first terminal device; The second terminal device according to claim 10.

18. determining at a first terminal device that user plane (UP) traffic is communicated between a first terminal device and a second terminal device without confidentiality protection; determining that the UP traffic is communicated between the first terminal device and the second terminal device without integrity protection or with partial integrity protection; sending a message to the second terminal device indicating that the UP traffic is communicated without the confidentiality protection or the integrity protection, or without the confidentiality protection and with the partial integrity protection; communicating the UP traffic between the first terminal device and the second terminal device without the confidentiality protection or the integrity protection, or without the confidentiality protection and with the partial integrity protection; A method comprising:

19. receiving a message from a first terminal device at the second terminal device indicating that user plane (UP) traffic is communicated between the first terminal device and the second terminal device without confidentiality or integrity protection, or without confidentiality protection and with partial integrity protection; communicating the UP traffic between the first terminal device and the second terminal device based on the message without the confidentiality protection or the integrity protection, or without the confidentiality protection and with the partial integrity protection; A method comprising:

20. A non-transitory computer readable medium comprising program instructions that cause an apparatus to perform at least the method of claim 18 or 19.

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