Communication method and apparatus, user device, mobility management device, and storage medium

Abstract

The present application relates to the technical field of communications, and discloses a communication method and apparatus, a user device, a mobility management device, and a storage medium. The communication method of the embodiments of the present application comprises: a user device (UE) receiving a first downlink non-access stratum (NAS) message, the first downlink NAS message comprising a first information element, and the first information element being used for a first mode; and when the first information element is abnormal, the UE disregarding the first information element.

Description

Communication method, apparatus, user equipment, mobility management device, and storage medium

[0001] Cross-reference to Related Applications

[0002] The present application claims priority to the Chinese patent application No. 202411318235.5, filed on September 20, 2024, the contents of which are incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application belongs to the field of communication technology, and specifically relates to a communication method, apparatus, user equipment, mobility management device, and storage medium. BACKGROUND

[0004] In non-terrestrial network (NTN) communication, a satellite operating mode of store and forward (S&F) is introduced. In this mode, the satellite can cache uplink or downlink messages when it is temporarily disconnected from the ground device (such as user equipment (UE) or core network device), and then forward the cached messages after the connection with the ground device is established.

[0005] However, the above-mentioned forwarding mode has certain security risks because it is disconnected from the network side device for a long time, thereby resulting in poor communication reliability. SUMMARY

[0006] Embodiments of the present application provide a communication method, apparatus, user equipment, mobility management device, and storage medium, which can improve the reliability of communication.

[0007] In a first aspect, a communication method is provided, which is performed by a UE, and the method comprises: receiving, by the UE, a first downlink non-access stratum (NAS) message, the first downlink NAS message comprising a first information element, the first information element being used for a first mode; and in a case where the first information element is abnormal, ignoring, by the UE, the first information element.

[0008] In a second aspect, a communication method is provided, which is performed by a mobility management device, and the method comprises: sending, by the mobility management device, a second downlink NAS message with security protection to a user equipment (UE), the second downlink NAS message comprising a second information element; and wherein the second information element is used to determine whether a first information element is abnormal, and the first information element is used for a first mode.

[0009] In a third aspect, a communication apparatus is provided, which comprises a receiving module and a processing module. The receiving module is configured to receive a first downlink NAS message, the first downlink NAS message comprising a first information element, the first information element being used for a first mode. The processing module is configured to ignore the first information element in a case that the first information element is abnormal.

[0010] In a fourth aspect, a communication apparatus is provided, which comprises a sending module. The sending module is configured to send, to a UE, a second downlink NAS message with security protection, the second downlink NAS message comprising a second information element, wherein the second information element is used to determine whether the first information element is abnormal, the first information element being used for a first mode.

[0011] In a fifth aspect, a communication apparatus is provided, which is configured to perform the steps of the method of the first aspect, or implement the steps of the method of the second aspect.

[0012] In a sixth aspect, a UE is provided, which comprises a processor and a memory, the memory storing programs or instructions executable on the processor, the programs or instructions being executed by the processor to implement the steps of the method of the first aspect.

[0013] In a seventh aspect, a UE is provided, which comprises a processor and a communication interface, wherein the communication interface is configured to receive a first downlink NAS message, the first downlink NAS message comprising a first information element, the first information element being used for a first mode, and the processor is configured to ignore the first information element in a case that the first information element is abnormal.

[0014] In an eighth aspect, a mobility management device is provided, which comprises a processor and a memory, the memory storing programs or instructions executable on the processor, the programs or instructions being executed by the processor to implement the steps of the method of the second aspect.

[0015] In a ninth aspect, a mobility management device is provided, which comprises a processor and a communication interface, wherein the communication interface is configured to send, to a UE, a second downlink NAS message with security protection, the second downlink NAS message comprising a second information element.

[0016] In a tenth aspect, a readable storage medium is provided, which stores programs or instructions, the programs or instructions being executed by a processor to implement the steps of the method of the first aspect, or implement the steps of the method of the second aspect.

[0017] In an eleventh aspect, a wireless communication system is provided, which comprises a terminal and a network side device, the terminal being configured to perform the steps of the method of the first aspect, and the network side device being configured to perform the steps of the method of the second aspect.

[0018] In a twelfth aspect, a chip is provided, the chip comprising a processor and a communication interface, the communication interface and the processor coupled, the processor configured to execute a program or instructions to implement the method of the first aspect, or to implement the method of the second aspect.

[0019] In a thirteenth aspect, a computer program / program product is provided, the computer program / program product stored in a storage medium, the computer program / program product executed by at least one processor to implement the steps of the communication method of the first aspect, or to implement the steps of the communication method of the second aspect.

[0020] In the embodiments of the present application, the UE receives a first downlink NAS message, the first downlink NAS message comprising a first information element, the first information element being used for a first mode; in the case that the first information element is abnormal, the UE ignores the first information element. In the present scheme, since the UE can judge whether the first information element for the first mode in the first downlink NAS message is abnormal after receiving the first downlink NAS message, and in the case that the first information element is abnormal, the UE ignores the first information element, and does not directly execute subsequent operations according to the first information element, the security problem existing in directly executing subsequent operations according to the first information element is avoided, thereby improving the reliability of communication. BRIEF DESCRIPTION OF DRAWINGS

[0021] FIG. 1 is a block diagram of a wireless communication system provided by the embodiments of the present application;

[0022] FIG. 2 is a flowchart of a communication method provided by the embodiments of the present application;

[0023] FIG. 3 is a flowchart of a communication method provided by the embodiments of the present application;

[0024] FIG. 4 is a flowchart of a communication method provided by the embodiments of the present application;

[0025] FIG. 5 is a flowchart of a communication method provided by the embodiments of the present application;

[0026] FIG. 6 is a flowchart of a communication method provided by the embodiments of the present application;

[0027] FIG. 7 is a flowchart of a communication method provided by the embodiments of the present application;

[0028] FIG. 8 is a flowchart of a communication method provided by the embodiments of the present application;

[0029] FIG. 9 is a flowchart of a communication method provided by the embodiments of the present application;

[0030] FIG. 10 is a flowchart of a communication method provided by the embodiments of the present application;

[0031] FIG. 11 is a flowchart of a communication method according to an embodiment of the present application;

[0032] FIG. 12 is a flowchart of a communication method according to an embodiment of the present application;

[0033] FIG. 13 is a flowchart of a communication method according to an embodiment of the present application;

[0034] FIG. 14 is a flowchart of a communication method according to an embodiment of the present application;

[0035] FIG. 15 is a flowchart of a communication method according to an embodiment of the present application;

[0036] FIG. 16 is a schematic diagram of a communication apparatus according to an embodiment of the present application;

[0037] FIG. 17 is a schematic diagram of a communication apparatus according to an embodiment of the present application;

[0038] FIG. 18 is a schematic diagram of a communication apparatus according to an embodiment of the present application;

[0039] FIG. 19 is a schematic diagram of a hardware structure of a UE according to an embodiment of the present application;

[0040] FIG. 20 is a schematic diagram of a hardware structure of a mobility management apparatus according to an embodiment of the present application. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art belong to the scope of protection of the present application.

[0042] The terms “first”, “second”, and the like in the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein, and the objects distinguished by “first”, “second” are generally of a kind and are not limited in number, for example, the first object can be one or more. In addition, “or” in the present application means at least one of the connected objects. For example, the protection scope of “A or B” at least covers three schemes, namely, scheme one: including A and not including B; scheme two: including B and not including A; scheme three: including A and B. In addition, the terms “A and / or B”, “at least one of A and B”, “at least one of A or B” also at least cover the above three schemes, respectively. The character “ / ” generally represents that the objects before and after are in an “or” relationship.

[0043] The term "indication" in this application can be either a direct indication (or explicit indication) or an indirect indication (or implicit indication). The direct indication can be understood as that the sender explicitly informs the receiver of specific information, operations to be performed or requested results, etc. in the sent indication. The indirect indication can be understood as that the receiver determines the corresponding information according to the indication sent by the sender, or judges and determines the operations to be performed or the requested results according to the judgment result.

[0044] It is worth noting that the techniques described in the embodiments of the present application are not limited to Long Term Evolution (LTE) / LTE-Advanced (LTE-A) systems, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA) or other systems. The terms "system" and "network" in the embodiments of the present application are often used interchangeably, and the described techniques can be used in the above-mentioned systems and radio technologies, as well as in other systems and radio technologies. The following description describes a New Radio (NR) system for example purposes, and NR terminology is used in most of the following description, but these techniques can also be applied to systems other than the NR system, such as a 6th Generation (6G) communication system.

[0045] FIG. 1 shows a block diagram of a wireless communication system to which embodiments of the present application can be applied. The wireless communication system includes a terminal 11 and a network-side device 12. The terminal 11 can be a terminal-side device such as a UE, a mobile phone, a Tablet Personal Computer, a Laptop Computer, a notebook computer, a Personal Digital Assistant, a palm computer, a netbook, an Ultra-mobile Personal Computer (UMPC), a Mobile Internet Device (MID), an Augmented Reality (AR) device, a Virtual Reality (VR) device, a robot, a Wearable Device, a flight vehicle, a Vehicle User Equipment (VUE), a shipboard device, a Pedestrian User Equipment (PUE), a smart home (a home device with a wireless communication function such as a refrigerator, a television, a washing machine, or furniture), a game console, a Personal Computer (PC), a kiosk, or a self-service machine. The Wearable Device includes a smart watch, a smart bracelet, a smart earphone, smart glasses, smart jewelry (a smart bracelet, a smart necklace, a smart ring, a smart necklace, a smart anklet, a smart necklace, etc.), a smart wristband, smart clothing, etc. The vehicle-mounted device can also be referred to as a vehicle-mounted terminal, a vehicle-mounted controller, a vehicle-mounted module, a vehicle-mounted component, a vehicle-mounted chip, or a vehicle-mounted unit, etc. It should be noted that the specific type of the terminal 11 is not limited in the embodiments of the present application. The network-side device 12 can include an access network device or a core network device. The access network device can also be referred to as a Radio Access Network (RAN) device, a radio access network function, or a radio access network unit. The access network device can include a base station, a Wireless Local Area Network (WLAN) Access Point (AP), or a Wireless Fidelity (WiFi) node, etc.The base station can be referred to as a Node B (NB), an evolved Node B (eNB), a next generation Node B (gNB), a New Radio Node B (NR Node B), an access point, a relay station (RBS), a serving base station (SBS), a base transceiver station (BTS), a radio base station, a radio transceiver, a basic service set (BSS), an extended service set (ESS), a home Node B (HNB), a home evolved Node B, a transmit / receive point (TRP), or some other suitable terminology in the art, and is not limited to a particular technical terminology, provided that the same technical effect is achieved. It should be noted that in the embodiments of the present application, only the base station in the NR system is taken as an example for introduction, and the specific type of the base station is not limited.

[0046] The core network device can also be referred to as a core network node, a core network function, or a core network network element, etc., which includes but is not limited to at least one of the following: a mobility management entity (MME), an access and mobility management function (AMF), a session management function (SMF), a user plane function (UPF), a policy control function (PCF), a policy and charging rules function (PCRF), an edge application server discovery function (EASDF), a unified data management (UDM), a unified data repository (UDR), a home subscriber server (HSS), a centralized network configuration (CNC), a network repository function (NRF), a network exposure function (NEF), a local NEF (L-NEF), a binding support function (BSF), an application function (AF), a location management function (LMF), a gateway mobile location center (GMLC), a network data analytics function (NWDAF), etc. It should be noted that only the core network device in the NR system is taken as an example for introduction in the embodiments of the present application, and the specific type of the core network device is not limited. If the name of the core network device mentioned in the embodiments of the present application changes in the subsequent protocol version (for example, 6G), it is also within the protection scope of the present application.

[0047] Optionally, the core network device can be implemented by one or more function modules in one device, or can be implemented by multiple devices jointly, and the embodiments of the present application do not make a specific limitation in this regard. It can be understood that the above function modules can be network elements in a hardware device, can be software function modules running on a dedicated hardware, or can be virtualized function modules instantiated on a platform (for example, a cloud platform).

[0048] In order to facilitate understanding of the scheme of the present application, the related technologies involved in the present application are explained and described below.

[0049] 1. NTN communication

[0050] NTN communication, namely non-terrestrial network communication, is a non-periodic communication system realized by using satellite technology. The system uses satellites as repeaters to transmit communication data between users through satellites, realizing seamless connection in a global range.

[0051] It should be noted that the satellite, namely Satellite, is abbreviated as SAT.

[0052] The core of the NTN satellite communication system is a group of communication satellites running in the orbit of the earth. These satellites are equipped with high-performance receiving and transmitting equipment, which can receive signals from ground users and forward them to other users or ground sites.

[0053] 2. S&F mode

[0054] In NTN communication, the store-and-forward mode is a data transmission mode. In this mode, after the satellite receives data from the UE, it will temporarily store these data and forward them to the core network device at an appropriate time. Similarly, the data sent by the core network device to the UE will also be transmitted in the store-and-forward mode through the satellite.

[0055] 3. SAT

[0056] SAT is a satellite in the sky, which can also be called a communication device, and it rotates around the earth, while the UE and other core network elements on the ground are relatively fixed in position relative to the SAT. Therefore, the SAT may lose the connection with the UE on the ground (referred to as service link) or the connection with the core network on the ground (referred to as feeder link). When the service link is available, the SAT needs to store the NAS signaling sent by the UE to the SAT, and wait until the feeder link is available, and then forward the NAS signaling to the ground network element.

[0057] The SAT can include the functions of a base station and a mobility management entity (MME), and can also include the function of a home subscriber server (HSS).

[0058] 4. Ground network element

[0059] The ground network element represents a core network element on the ground. The ground network element can be an MME or an HSS, depending on the functions included in the SAT.

[0060] When the SAT includes the functions of a base station and an MME, the ground network element is also an MME. When the ground network element receives an uplink request sent by the SAT, which is an uplink NAS message, the downlink response sent by the ground network element is a downlink NAS message generated by the ground MME based on the uplink NAS message.

[0061] When the SAT includes the functions of the entire core network (at least including a base station, an MME, and an HSS), the ground network element can be an HSS. When the ground network element receives an uplink request sent by the SAT, which is a message generated based on an uplink NAS message and used for communication with the HSS, the downlink response sent by the ground network element is a response message generated by the ground HSS based on the message, so that the MME of the SAT can generate a downlink NAS message based on the response message.

[0062] 5. Tracking area identity (TAI)

[0063] The TAI is an identifier in a 5G network, used to identify a tracking area in which a mobile device is located. A tracking area refers to a group of adjacent cells used for mobility management of the mobile device.

[0064] 6. FIG. 2 is a basic flowchart of the SAT performing S&F in the S&F scenario in the related art, which can include the following steps S1-S13.

[0065] The service link of the SAT1 is available:

[0066] S1. The SAT1 performs broadcasting, and the broadcasting carries an S&F indication, which is used to indicate that the current mode is an S&F mode.

[0067] S2. After the UE decides to perform the S&F mode, the UE selects the SAT according to the S&F indication.

[0068] S3. The UE sends an uplink NAS message to the SAT1.

[0069] S4, if the information currently stored in the SAT1 cannot complete the uplink NAS message, the uplink request message required to be sent to the ground network element is obtained and saved according to the uplink NAS message, and the NAS Reject message is sent to the UE.

[0070] The information currently stored in the SAT1 cannot complete the uplink NAS message can be specifically represented as:

[0071] a) SAT1 does not have the UE security context; b) the integrity protection check of the uplink NAS message fails; 3) SAT1 cannot obtain the authentication vector or subscription information of the UE; d) SAT1 cannot independently process the uplink NAS message (requires cooperation with the ground network element).

[0072] SAT1 obtains the uplink request message according to the uplink NAS message, which can be specifically represented as:

[0073] a) under the condition that the SAT1 contains the base station and the MME, the uplink request message is the uplink NAS message, and the MME function of the SAT1 only forwards the uplink NAS message.

[0074] b) under the condition that the SAT1 contains the entire core network function, the uplink request message can be a message generated according to the uplink NAS message for communication with the ground function, for example, in the case that the uplink NAS message is an attach request or a registration request, the uplink request message can be an authentication vector acquisition message.

[0075] S5, the SAT1 sends the NAS Reject message to the UE.

[0076] The NAS Reject message contains the S&F rejection reason value, and optionally contains the rejection duration, the satellite list.

[0077] S6, the UE performs related operations according to each information element in the NAS Reject message:

[0078] In the case of receiving the S&F rejection reason value, the UE can select different public land mobile networks (PLMNs) to continue to obtain services.

[0079] In the case of receiving the rejection duration, when the rejection duration is reached or exceeded, the UE re-sends the uplink NAS message.

[0080] In the case of receiving the satellite list, when the UE re-sends the uplink NAS message, the uplink NAS message is sent to the satellite in the satellite list.

[0081] The feeder link of the SAT1 is available:

[0082] S7, SAT1 sends the saved uplink request message to the ground network element.

[0083] S8, the ground network element obtains a downlink response message according to the uplink request message, and saves the downlink response message.

[0084] The ground network element obtaining a downlink response message according to the uplink request message is specifically:

[0085] a) under the condition that SAT1 contains a base station and an MME, the downlink response message is a downlink NAS message, wherein the downlink NAS message is generated by the ground MME according to the uplink NAS message, and the ground MME can obtain parameters for generating the downlink NAS message from other ground network elements such as an HSS according to the uplink NAS message, for example, the uplink NAS message is an Attach Request, the ground MME requests an authentication vector from the HSS according to the uplink NAS message, and then generates a downlink NAS message of an Authentication Request according to the authentication vector.

[0086] b) under the condition that SAT1 contains the entire core network function, the downlink response message can be a message generated by the ground network element according to the uplink request message, for example, in the case that the uplink request message is an authentication vector acquisition message, the downlink response message is an authentication vector response message, so that SAT1 can generate a downlink NAS message according to the authentication vector response message.

[0087] The feeder link of SAT2 is available:

[0088] S9, the ground network element sends the downlink response message to SAT2.

[0089] S10, SAT2 saves the downlink response message.

[0090] The service link of SAT2 is available:

[0091] S11, the UE determines to send the uplink NAS message again according to the information element of step S6.

[0092] S12, the UE sends the uplink NAS message to SAT2.

[0093] S13, SAT2 sends the saved downlink NAS message to the UE.

[0094] That is, one round of NAS interaction is completed.

[0095] It can be understood that SAT1 and SAT2 can be different communication satellites, or can be the same communication satellite.

[0096] In the related art described above, the key for the UE to send the uplink NAS message to the SAT again is to understand the three information elements in the NAS Reject message. However, since the NAS Reject message is not integrity protected, the following attacks may exist:

[0097] The first case: the NAS Reject message is a general NAS message, and thus can be used in both normal scenarios and S&F scenarios. However, since the NAS Reject message is not integrity protected, the introduction of the three new information elements in the S&F scenario may affect the UE in the normal scenario, such as the Terrestrial Network (TN). For example, the UE receives a fake NAS Reject message containing the S&F rejection cause value in the normal scenario, which may cause the UE to reselect a PLMN in the normal scenario, resulting in interruption of normal services; the UE receives a fake NAS Reject message containing the rejection duration in the normal scenario, which may cause the UE to initiate an uplink NAS message in the rejection duration, resulting in a DoS attack on normal services, which is referred to as attack 1 below. This attack 1 can be generally summarized as an attack beyond the applicable range of the information element.

[0098] The second case: the NAS Reject message itself does not have integrity protection, and there is a risk in the S&F scenario. For example, the UE receives a fake NAS Reject message containing a rejection duration (too long or incorrect time) in the S&F scenario, which may cause the UE to wait for too long in the S&F scenario or to recover at the wrong time, resulting in a DoS attack on S&F services. The UE receives a fake NAS Reject message containing a satellite list (incorrect satellite list) in the S&F scenario, which may cause the UE to make an error when selecting a satellite, thereby causing a DoS attack on S&F services, which is referred to as attack 2 below. This attack 2 can be generally summarized as an attack caused by abnormal values of the information element.

[0099] To solve the above problems, the following three strategies are proposed to solve the above security problems.

[0100] Strategy one: limit the use range of S&F information elements

[0101] The UE responds to the S&F rejection cause value, the rejection duration, and the satellite list in the NAS Reject message only after entering the S&F mode. The UE ignores the S&F rejection cause value, the rejection duration, and the satellite list in the NAS Reject message when the UE is not in the S&F mode.

[0102] The communication method provided in the embodiments of the present application can prevent the S&F information element that is not protected by security from affecting the execution of normal services, thereby solving the attack 1.

[0103] Policy two: detecting validity of information element

[0104] The UE can detect the validity of the S&F information element according to a preconfigured policy or a network configured policy when entering the S&F mode. The preconfigured policy or the network configured policy is a reasonable value range of the S&F information element. If the S&F information element is not in the reasonable value range, the UE ignores the S&F rejection reason value, the rejection duration and the satellite list in the NAS Reject message.

[0105] The communication method provided in the embodiments of the present application can prevent the S&F information element that is not protected by security from affecting the execution of normal services, thereby solving the attack 1.

[0106] Policy three: preferentially using S&F information element obtained from a secure transmission channel

[0107] After the UE has obtained the preconfigured policy or the network configured policy, the UE can ignore the S&F information element in the NAS Reject message and use the reasonable value range of the S&F information element in the policy for subsequent actions.

[0108] The communication method provided in the embodiments of the present application can prevent the S&F information element that is not protected by security from affecting the execution of normal services, thereby solving the attack 1.

[0109] It should be noted that for initial access, the UE and the network side device have not established NAS security, and therefore it is difficult to use a cryptographic method for protection. Therefore, the above three policies can be used to alleviate the above security problems.

[0110] The communication provided in the embodiments of the present application will be described in detail in combination with some embodiments and application scenarios and the accompanying drawings.

[0111] FIG. 3 is a flowchart of a communication method provided in the embodiments of the present application. As shown in FIG. 3, the communication method can include the following steps 201 and 202.

[0112] Step 201, the UE receives a first downlink NAS message.

[0113] In embodiments of the present application, the first downlink NAS message includes a first information element, and the first information element is used for the first mode.

[0114] In some embodiments of the present application, the first mode is a store-and-forward mode, i.e., an S&F mode.

[0115] In some embodiments of the present application, the first downlink NAS message is a NAS reject message, and the NAS reject message is used to indicate that a rejection in the first mode has occurred. The first downlink NAS message is not protected by security.

[0116] It can be understood that when the UE receives the first downlink NAS message, the UE can first determine whether the first information element in the first downlink NAS message is abnormal. When the first information element is abnormal, the UE ignores the first information element, so as to prevent the information element that is not protected by security from affecting the execution of normal services.

[0117] In some embodiments of the present application, the rejection in the first mode can be understood as follows: when the UE sends an uplink NAS message to a communication device (i.e., a SAT) and the UE is in the first mode, if the information currently stored in the communication device cannot complete the uplink NAS message, the communication device can send a downlink NAS reject message to the UE.

[0118] In some embodiments of the present application, after the UE sends an uplink NAS message to a communication device, the UE can receive a first downlink NAS message that is not protected by security when the UE is in a store-and-forward mode. For example, the UE receives a NAS reject message that includes a fake first information element.

[0119] In some embodiments of the present application, after the UE sends an uplink NAS message to a communication device, the UE can also receive a first downlink NAS message that is not protected by security when the UE is not in a store-and-forward mode. For example, the UE receives a fake NAS reject message.

[0120] Step 202, the UE ignores the first information element when the first information element is abnormal.

[0121] It can be understood that the UE responds to the first information element in the NAS reject message only when the first information element is not abnormal. When the first information element is abnormal, the UE ignores the first information element in the NAS reject message.

[0122] The embodiment of the present application provides a communication method. Since the UE can determine whether the first information element for the first mode in the first downlink NAS message is abnormal after receiving the first downlink NAS message, and in the case that the first information element is abnormal, the first information element is ignored, and the subsequent operation is not directly performed according to the first information element, the security problem existing in the direct execution of the subsequent operation according to the first information element is avoided, and therefore the reliability of the communication is improved.

[0123] In some embodiments of the present application, the first information element includes at least one of the following: a rejection reason value, a rejection duration, and a first communication device list.

[0124] In some embodiments of the present application, the rejection reason value is used to indicate the reason for the rejection in the first mode; the rejection duration is used to indicate the duration that the UE needs to wait before sending the uplink NAS message; and the first communication device list includes the identity of at least one communication device that supports the first mode.

[0125] For example, as shown in FIG. 2, in the case that the first mode is the S&F mode, the NAS Reject message sent by the SAT1 to the UE in step S5 can include at least one of the following: a rejection reason value (i.e., an S&F rejection reason value), a rejection duration, and a first communication device list (i.e., the satellite list).

[0126] In some embodiments of the present application, the reason for the rejection in the first mode can include at least one of the following:

[0127] The communication device receiving the uplink NAS message sent by the UE does not have the UE security context;

[0128] The communication device receiving the uplink NAS message sent by the UE fails in the integrity protection check of the uplink NAS message;

[0129] The communication device receiving the uplink NAS message sent by the UE cannot obtain the authentication vector or the subscription information of the UE;

[0130] The communication device receiving the uplink NAS message sent by the UE cannot process the uplink NAS message in the first mode.

[0131] In some embodiments of the present application, the uplink NAS message sent by the UE can be the first uplink NAS message in the following step 601.

[0132] In some embodiments of the present application, the communication device cannot process the received uplink NAS message in the first mode can be understood as that the communication device needs the cooperation of the ground network element to process the uplink NAS message.

[0133] In some embodiments of the present application, the rejection duration is specifically used to indicate the time for the UE to wait before sending the uplink NAS message again.

[0134] In some embodiments of the present application, the at least one communication device specifically indicates the communication device that the UE can select to send the uplink NAS message again.

[0135] In some embodiments of the present application, the first information element can be referred to as an S&F information element.

[0136] In some embodiments of the present application, after the UE sends the uplink NAS message to the ground network, the UE can also receive a fake first downlink NAS message when the UE is not in the store-and-forward mode. The UE can determine that the first information element is abnormal when it is determined that the UE is not in the store-and-forward mode, so as to ignore the first information element, i.e., the above-mentioned strategy one.

[0137] In some embodiments of the present application, in combination with FIG. 3, as shown in FIG. 4, before the step 202, the communication method provided by the embodiments of the present application can further include the following step 301.

[0138] Step 301: When the UE is not in the first mode, the UE determines that the first information element is abnormal.

[0139] In some embodiments of the present application, after the UE sends the uplink NAS message, if the UE receives the first downlink NAS message, the UE can determine whether the UE is in the first mode. When the UE is not in the first mode, the UE can determine that the first information element is abnormal.

[0140] For example, after the UE sends the uplink NAS message, if the UE receives the first downlink NAS message, the UE can determine whether the UE is in the store-and-forward mode. When the UE is not in the store-and-forward mode, the UE can determine that the first information element is abnormal.

[0141] In some embodiments of the present application, the step 301 can be specifically implemented by the following step 301a.

[0142] Step 301a: When the first condition is met, the UE determines that the UE is not in the first mode to determine that the first information element is abnormal.

[0143] In some embodiments of the present application, the first condition includes at least one of the following:

[0144] The UE receives a broadcast message from the communication device, and the broadcast message does not contain the indication information used to indicate that the communication device supports the first mode;

[0145] The UE determines according to the local setting that the UE is not in the first mode;

[0146] The uplink NAS message sent by the UE does not contain first capability information indicating that the UE supports the first mode; or the uplink NAS message sent by the UE contains second capability information indicating that the UE does not support the first mode.

[0147] It can be understood that when the UE receives the broadcast message from the communication device without the S&F indication, the UE can determine that the UE is not in the store-and-forward mode because the communication device does not support the store-and-forward mode.

[0148] It can be understood that when the UE detects that the local setting of the UE is not in the store-and-forward mode, the UE can determine that the UE is not in the store-and-forward mode.

[0149] In some embodiments of the present application, a user can set (i.e., the above-mentioned local setting) the UE to leave the store-and-forward mode so that the UE is not in the store-and-forward mode.

[0150] It can be understood that when the uplink NAS message sent by the UE does not contain the S&F capability, i.e., the above-mentioned first capability information, the UE can determine that the UE is not in the store-and-forward mode. Or, when the uplink NAS message sent by the UE directly indicates that the UE does not support the first mode, the UE can determine that the UE is not in the store-and-forward mode.

[0151] In some embodiments of the present application, after the UE decides to enter the store-and-forward mode, the UE can carry first capability information indicating that the UE supports the store-and-forward mode in the uplink NAS message. Therefore, when the uplink NAS message sent by the UE does not contain the first capability information, the UE can determine that the UE is not in the store-and-forward mode.

[0152] In some embodiments of the present application, under normal circumstances, when the first capability information indicating that the UE supports the store-and-forward mode is not carried in the uplink NAS message, the downlink NAS rejection message received by the UE does not contain the first information element. Therefore, when the UE determines that the UE is not in the store-and-forward mode because the uplink NAS message sent by the UE does not contain the above-mentioned first capability information, the UE can determine that the first information element in the received downlink NAS rejection message is abnormal.

[0153] Thus, because the UE can ignore the S&F information element in the NAS rejection message by judging that the UE is not in the S&F mode, the S&F information element that is not security protected can be prevented from affecting the execution of normal services, i.e., the above-mentioned strategy one.

[0154] In some embodiments of the present application, as shown in FIG. 5, before the step 202, the communication method provided by the embodiments of the present application can further include the following steps 401 and 402 in combination with FIG. 3.

[0155] Step 401, the UE obtains a second information element.

[0156] In embodiments of the present application, the second information element is pre-configured on the UE or obtained from a message with security protection.

[0157] In some embodiments of the present application, the second information element pre-configured on the UE (i.e., the pre-configured policy) can be hardcoded on the UE or configured by a user.

[0158] In some embodiments of the present application, the second information element obtained from the message with security protection (i.e., the network-configured policy) can be configured by a mobility management device.

[0159] For example, the mobility management device can be understood as the ground network element mentioned above.

[0160] In some embodiments of the present application, the second information element obtained from the message with security protection can be obtained after the UE successfully completes the S&F communication by the SAT, or can be obtained when the UE completes normal communication with the mobility management device.

[0161] It can be understood that after obtaining the second information element, in a subsequent new round of S&F process or in a normal scenario (UE accesses the TN ground network), if the UE receives a NAS rejection message, the saved second information element can be used to detect the validity of the S&F information element in the NAS rejection message, i.e., to detect whether the S&F information element is abnormal, so that the S&F information element is ignored when the S&F information element is abnormal.

[0162] In some embodiments of the present application, the second information element is obtained from a message with security protection, and the step 401 can be implemented by the following step 401a.

[0163] Step 401a, the UE receives a second downlink NAS message.

[0164] In embodiments of the present application, the second downlink NAS message is a message with security protection, and the second downlink NAS message includes the second information element.

[0165] It should be noted that the step 401a can be performed before the step 201.

[0166] In some embodiments of the present application, the UE can receive the second downlink NAS message sent by the mobility management device.

[0167] In some embodiments of the present application, before the step 401a, the communication method provided by the embodiments of the present application can further include the following step 403.

[0168] Step 403, the UE sends an uplink NAS message for requesting the second information element.

[0169] In some embodiments of the present application, the UE can send an uplink NAS message for requesting the second information element to the mobility management device.

[0170] It can be understood that the UE can send an uplink NAS message for requesting the second information element to the mobility management device, and then when receiving the second downlink NAS message sent by the mobility management device, the UE can obtain the second information element, so that when receiving the first downlink NAS message subsequently, the UE can determine whether the first information element in the first downlink NAS message is abnormal according to the second information element.

[0171] Specifically, the UE requesting the second information element from the mobility management device can include the following two ways:

[0172] Way one (the UE communicates with the mobility management device through the SAT to request the second information element from the mobility management device):

[0173] The UE can send an uplink NAS message for requesting the second information element to the mobility management device through the communication device (i.e. the SAT). It can be understood that the UE can send an uplink NAS message for requesting the second information element to the communication device, and the communication device can forward the uplink NAS message to the mobility management device. After the mobility management device receives the uplink NAS message, the mobility management device can send a second downlink NAS message to the communication device, and then the communication device forwards the second downlink NAS message to the UE.

[0174] In some embodiments of the present application, the above-mentioned uplink NAS message for requesting the second information element can include first capability information, and the first capability information is used to indicate that the UE supports the store-and-forward mode.

[0175] In some embodiments of the present application, the above-mentioned uplink NAS message for requesting the second information element can include first indication information, and the first indication information is used to request the second information element. The first indication information can be a new information element, or can reuse an existing S&F information element (for example, the above-mentioned first capability information).

[0176] Exemplarily, when the above-mentioned first indication information is a new information element, the first indication information is used to request the second information element, and optionally, can also be used to indicate that the UE supports the protection for the first mode.

[0177] Exemplarily, when the above-mentioned first indication information is to reuse the existing first capability information, the first capability information is used to indicate that the UE supports the store-and-forward mode, and is also used to request the second information element.

[0178] In some embodiments of the present application, the UE can send an uplink NAS message for requesting the second information element to the communication device, the NAS message comprising the first indication information, and then the communication device can send an uplink request message carrying the first indication information to the mobility management device after receiving the uplink NAS message, and the mobility management device can send a second downlink NAS message to the communication device according to the first indication information in the uplink request message, and carry the second information element in the second downlink NAS message, and then the communication device can forward the second downlink NAS message to the UE.

[0179] In some embodiments of the present application, when the first indication information is not included in the uplink NAS message for requesting the second information element, the communication device can generate the second indication information according to the first capability information in the uplink NAS message after receiving the uplink NAS message, the second indication information being used for requesting the second information element, and optionally, being used for indicating that the UE supports the store-and-forward mode or indicating that the UE supports the protection for the first mode, and then the communication device can send an uplink request message carrying the second indication information to the mobility management device, and the mobility management device can send a second downlink NAS message to the communication device according to the second indication information in the uplink request message, and carry the second information element in the second downlink NAS message, and then the communication device can forward the second downlink NAS message to the UE.

[0180] In some embodiments of the present application, the second information element can be pre-configured on the mobility management device.

[0181] For example, when the first indication information is not included in the uplink NAS message for requesting the second information element, the UE requesting the second information element can include the following steps S21 to S33, as shown in FIG. 6.

[0182] SAT1 is available for service link:

[0183] S21, the SAT1 broadcasts, and carries the S&F indication in the broadcast, the S&F indication being used for indicating that the current is the S&F working mode.

[0184] S22, when the UE decides to perform the S&F mode, the UE selects the SAT1 according to the S&F indication.

[0185] S23, the UE sends an uplink NAS message to the SAT1.

[0186] In some embodiments of the present application, the uplink NAS message can comprise the first capability information, the first capability information being used for indicating that the UE supports the store-and-forward mode.

[0187] S24, if the information currently stored in SAT1 cannot complete the uplink NAS message, SAT1 sends a NAS Reject message to the UE, and generates second indication information according to the first capability information in the uplink NAS message, and saves the uplink request message carrying the second indication information sent to the ground network element.

[0188] S25, SAT1 sends a NAS Reject message to the UE.

[0189] S26, the UE performs relevant operations according to each information element in the NAS Reject message.

[0190] The feeder link of SAT1 is available:

[0191] S27, SAT1 sends the saved uplink request message to the ground network element.

[0192] S28, the ground network element determines the second information element according to the second indication information in the uplink request message, obtains and saves the downlink response message carrying the second information element sent to SAT.

[0193] The feeder link of SAT2 is available:

[0194] S29, the ground network element sends the downlink response message carrying the second information element to SAT2.

[0195] S30, SAT2 saves the downlink response message carrying the second information element.

[0196] The service link of SAT2 is available:

[0197] S31, the UE determines to send the uplink NAS message again according to the information element in step S26.

[0198] S32, the UE sends the uplink NAS message to SAT2.

[0199] S33, SAT2 sends a downlink NAS message carrying the second information element to the UE.

[0200] In step S33, SAT2 carries the reasonable value of the S&F information element, i.e. the second information element, in the downlink NAS message, so that the UE saves the reasonable value of the S&F information element, and when receiving the NAS Reject message in the subsequent execution of a new round of S&F process, the UE can use the saved reasonable value of the S&F information element to detect the validity of the S&F information element in the NAS Reject message.

[0201] It can be understood that, compared with the flow in FIG. 2, the difference between the first mode of the present application and the related art is that the SAT 1 can generate the second indication information according to the first capability information in the uplink NAS message, and send the uplink request message carrying the second indication information to the ground network element, so that the ground network element can determine the second element according to the second indication information in the uplink request message after receiving the uplink request message, and send the downlink response message carrying the second element to the SAT 2 when the SAT 2 is available, and then the UE can obtain the second element from the downlink NAS message carrying the second element sent by the SAT 2 when sending the uplink NAS message to the SAT 2. In this way, when the NAS Reject message is received, the UE can use the saved reasonable value of the second element to detect the validity of the S&F element in the NAS Reject message.

[0202] The second mode (UE normally communicates with the mobility management device through the ground network to request the second element from the mobility management device):

[0203] It can be understood that the UE can send the uplink NAS message for requesting the second element to the ground network, the ground network can forward the uplink NAS message to the mobility management device, and the mobility management device can send the second downlink NAS message to the ground network after receiving the uplink NAS message, and then the ground network forwards the second downlink NAS message to the UE.

[0204] In some embodiments of the present application, the uplink NAS message for requesting the second element can include: first capability information, the first capability information being used to indicate that the UE supports the store-and-forward mode.

[0205] In some embodiments of the present application, the uplink NAS message for requesting the second element can include: third indication information, the third indication information being used to request the second element, and the third indication information can be a new element or reuse the existing S&F element (for example, the first capability information described above).

[0206] Exemplarily, when the third indication information is a new element, the third indication information is used to request the second element, and optionally, can also be used to indicate that the UE supports the protection for the first mode.

[0207] Exemplarily, when the third indication information reuses the existing first capability information, the first capability information is used to request the second element in addition to indicating that the UE supports the store-and-forward mode.

[0208] In some embodiments of the present application, the uplink NAS message used for requesting the second information element can be any one of the following: an Attach request message, a Terminal Access Unit (TAU) request message.

[0209] In some embodiments of the present application, the UE can send an uplink NAS message used for requesting the second information element to the ground network, and the uplink NAS message carries third indication information. Then, after receiving the uplink NAS message, the ground network can forward the uplink NAS message to the mobility management device. After receiving the uplink NAS message, the mobility management device can send a second downlink NAS message to the ground network according to the third indication information in the uplink NAS message, and the second downlink NAS message carries the second information element. Then, the ground network can forward the second downlink NAS message to the UE.

[0210] In some embodiments of the present application, when the third indication information is not included in the uplink NAS message used for requesting the second information element, after receiving the uplink NAS message, the ground network can generate fourth indication information according to the first capability information in the uplink NAS message. The fourth indication information is used for requesting the second information element, and can be used for indicating that the UE supports the store-and-forward mode or indicating that the UE supports the protection for the first mode. Then, the ground network sends an uplink request message carrying the fourth indication information to the mobility management device. After receiving the uplink request message, the mobility management device can send a second downlink NAS message to the ground network according to the fourth indication information in the uplink request message, and the second downlink NAS message carries the second information element. Then, the ground network can forward the second downlink NAS message to the UE.

[0211] In some embodiments of the present application, the ground network can be a Radio Access Network (RAN), or other network having the same function as the RAN, and the embodiments of the present application do not limit this.

[0212] In some embodiments of the present application, the mobility management device accessed by the UE through the SAT can be the same as or different from the mobility management device accessed by the UE through the ground network, and the embodiments of the present application do not limit this.

[0213] For example, taking the ground network as the RAN, as shown in FIG. 7, the UE requesting the second information element can specifically include the following steps S41 to S46.

[0214] S41, the UE sends an uplink NAS message carrying third indication information to the RAN.

[0215] S42, the RAN forwards the uplink NAS message to the ground network element.

[0216] S43, the ground network element determines the second information element according to third indication information in the uplink NAS message.

[0217] S44, the ground network element sends a downlink NAS message carrying the second information element to the RAN.

[0218] S45, the RAN forwards the downlink NAS message carrying the second information element to the UE.

[0219] S46, the UE saves the second information element in the downlink NAS message.

[0220] In step S46, the UE saves the S&F information element in the downlink NAS message, and when receiving the NAS Reject message in the subsequent execution of a new round of S&F process, the UE can use the saved S&F information element to detect the validity of the S&F information element in the NAS Reject message.

[0221] In some embodiments of the present application, the second information element is an information element corresponding to the location information of the location where the UE currently locates.

[0222] In some embodiments of the present application, the uplink NAS message used to request the second information element can include location information, which is the location information of the location where the UE currently locates, so that the mobility management device can determine the second information element corresponding to the location information according to the location information in the uplink NAS message after receiving the uplink NAS message used to request the second information element, and carry the second information element corresponding to the location information in the second downlink NAS message when sending the second downlink NAS message to the UE.

[0223] In some embodiments of the present application, the uplink NAS message used to request the second information element can be sent to the mobility management device in a bearing message together with location information, which is the location information of the location where the UE currently locates. The bearing message is determined by the ground network or the communication device, or the location information can also be determined by the ground network or the communication device according to the location where the UE currently locates, and the bearing message can be an N2 message.

[0224] In some embodiments of the present application, the location information can be any one of the following: PLMN, TAI, etc.

[0225] In some embodiments of the present application, for the above-mentioned mode one, the UE can send an uplink NAS message for requesting the second service cell to the communication device, the uplink NAS message including the first indication information, then the communication device can generate location information according to the current location of the UE after receiving the uplink NAS message, and send an uplink request message to the mobility management device, the uplink request message carrying the uplink NAS message and the location information of the current location of the UE, after the mobility management device receives the uplink request message, the mobility management device can determine the second service cell corresponding to the location information according to the first indication information and the location information, and send a second downlink NAS message to the communication device, the second downlink NAS message carrying the second service cell corresponding to the location information, then the communication device can forward the second downlink NAS message to the UE, so that the UE obtains the second service cell; or,

[0226] The UE can send an uplink NAS message for requesting the second service cell to the communication device, then the communication device can generate location information according to the current location of the UE after receiving the uplink NAS message, and generate the second indication information according to the first capability information in the uplink NAS message, and send an uplink request message to the mobility management device, the uplink request message carrying the second indication information and the location information of the current location of the UE, after the mobility management device receives the uplink request message, the mobility management device can determine the second service cell corresponding to the location information according to the second indication information and the location information, and send a second downlink NAS message to the communication device, the second downlink NAS message carrying the second service cell corresponding to the location information, then the communication device can forward the second downlink NAS message to the UE, so that the UE obtains the second service cell.

[0227] In some embodiments of the present application, for the above-mentioned mode two, the UE can send an uplink NAS message for requesting the second service cell to the ground network, the uplink NAS message including the third indication information, then the ground network can generate location information according to the current location of the UE after receiving the uplink NAS message, and send the uplink NAS message and the location information to the mobility management device, after the mobility management device receives the uplink NAS message and the location information, the mobility management device can determine the second service cell corresponding to the location information according to the third indication information and the location information, and send a second downlink NAS message to the ground network, the second downlink NAS message carrying the second service cell corresponding to the location information, then the ground network can forward the second downlink NAS message to the UE, so that the UE obtains the second service cell.

[0228] In some embodiments of the present application, the second downlink NAS message further comprises location information of a location where the UE currently locates, and the location information corresponds to the second information element; and the step 401 can be implemented by the following step 401b.

[0229] The step 401b comprises: obtaining, by the UE, the location information according to the location where the UE currently locates, and obtaining the second information element from the second downlink NAS message according to the location information.

[0230] In some embodiments of the present application, the second downlink NAS message comprises at least two information elements, and each information element corresponds to one location information.

[0231] In some embodiments of the present application, the UE can obtain the location information according to the location where the UE currently locates, and then determine the information element corresponding to the location information of the UE from the at least two information elements according to the location information, as the second information element.

[0232] For example, assuming that the second downlink NAS message comprises information element A and information element B, i.e. the at least two information elements, the information element A corresponds to PLMN1, and the information element B corresponds to PLMN2, and then the UE currently locates in the PLMN1, the UE can obtain the information element A, i.e. the information element A corresponding to the PLMN1, as the second information element.

[0233] For another example, assuming that the second downlink NAS message comprises information element A and information element B, i.e. the at least two information elements, the information element A corresponds to TAI1, and the information element B corresponds to TAI2, and then the UE currently locates in the TAI1, the UE can obtain the information element A, i.e. the information element A corresponding to the TAI1, as the second information element.

[0234] It can be understood that the mobility management device does not directly carry the second information element corresponding to the location information of the location where the UE currently locates in the second downlink NAS message to the UE, but carries the at least two information elements pre-configured on the mobility management device and the location information corresponding to the at least two information elements in the second downlink NAS message to the UE, so that subsequently, the UE can obtain the location information according to the location where the UE currently locates when receiving the second downlink NAS message, and then determine the information element corresponding to the location information of the UE from the at least two information elements according to the location information, as the second information element.

[0235] The step 402 comprises: determining, by the UE, that the first information element is abnormal according to the second information element.

[0236] In some embodiments of the present application, the determination of whether the first information element is abnormal by the UE can also be understood as detecting the validity of the first information element.

[0237] In some embodiments of the present application, the UE detecting the validity of the first information element can specifically be that the UE judges whether the received first information element is within a reasonable value range of the second information element, and if the first information element is not within the reasonable value range of the second information element, the UE ignores the first information element.

[0238] In some embodiments of the present application, the first information element includes at least one of the following: a rejection time length and a first communication device list, the rejection time length is used to indicate a time length for which the UE needs to wait before sending an uplink NAS message, and the first communication device list includes an identifier of at least one communication device that supports the first mode; and the step 402 can be implemented by the following step 402a.

[0239] In the step 402a, the UE determines that the first information element is abnormal when the first information element meets a second condition.

[0240] In the embodiments of the present application, the second condition includes at least one of the following:

[0241] The rejection time length is not within a reasonable time length range included in the second information element;

[0242] The first communication device list includes an identifier of a communication device other than the second communication device list included in the second information element.

[0243] In some embodiments of the present application, the second information element includes at least one of the following: a reasonable time length range and a second communication device list.

[0244] In some embodiments of the present application, a maximum value of the reasonable time length range can be determined according to a time required for a communication device to make one round of the earth, and a minimum value of the reasonable time length range can be determined according to a time required for a next communication device to move to a service range.

[0245] For example, the maximum value of the reasonable time length range is a time length required for a communication device to make one round of the earth, and the minimum value of the reasonable time length range is a time length required for a next communication device to move to a service range.

[0246] In some embodiments of the present application, the second communication device list can be expressed as a list of addressable valid communication devices, i.e., a list of addressable valid satellites.

[0247] In some embodiments of the present application, if the first information element includes a rejection time length, the UE can judge whether the rejection time length is within a reasonable time length range included in the second information element, and when the rejection time length is not within the reasonable time length range included in the second information element, the UE determines that the first information element is abnormal.

[0248] In some embodiments of the present application, if the first information element includes a first communication device list, the UE can determine whether the first communication device list contains an identifier of a communication device other than the second communication device list included in the second information element, and determine that the first information element is abnormal when the first communication device list contains an identifier of a communication device other than the second communication device list included in the second information element.

[0249] In some embodiments of the present application, the first communication device list containing an identifier of a communication device other than the second communication device list included in the second information element can also be understood as that there is at least one identifier of a communication device in the first communication device list that is not in the second communication device list included in the second information element.

[0250] In this way, since the UE ignores the first information element in the NAS Reject when determining that the first information element is not within a reasonable range, the execution of the S&F service can be prevented from being affected by the first information element that is not securely protected, i.e., the second strategy described above.

[0251] In some embodiments of the present application, the communication method provided by the embodiments of the present application can further include the following step 404.

[0252] Step 404: In the case of abnormal first information element, the UE sends an uplink NAS message according to the second information element.

[0253] In some embodiments of the present application, in the case of determining that the first information element is abnormal, the UE can send an uplink NAS message according to at least one of the reasonable time range and the second communication device list included in the second information element.

[0254] In this way, since the UE can obtain the second information element in a secure manner, the second information element is used for subsequent operations after receiving the unsafe first information element, which can ensure the accuracy of the information element, i.e., the third strategy described above.

[0255] In some embodiments of the present application, the communication method provided by the embodiments of the present application can further include the following step 405.

[0256] Step 405: In the case of abnormal first information element, after waiting for a first time, the UE sends an uplink NAS message to one of the communication devices in the second communication device list.

[0257] In some embodiments of the present application, the second communication device list includes at least one identifier of a communication device, and each communication device is an addressable valid communication device. The UE can select one of the communication devices from the second communication device list.

[0258] In some embodiments of the present application, the first time is a lower limit value in the reasonable time range.

[0259] It can be understood that, in the case of determining that the first information element is abnormal, the UE can send the uplink NAS message according to the reasonable time range and the second communication device list included in the second information element.

[0260] In some embodiments of the present application, the second information element described above can further include a fixed second time length instead of a reasonable time range, and in the case of determining that the first information element is abnormal, the UE can send the uplink NAS message to a communication device in the second communication device list after waiting for the second time length.

[0261] In this way, since the UE can obtain the second information element in a safe manner, the second information element is preferentially used for subsequent operations after receiving the unsafe first information element, and the accuracy of the information element can be ensured.

[0262] In some embodiments of the present application, the communication method provided by the embodiments of the present application can further include the following step 501.

[0263] For example, in combination with FIG. 3, as shown in FIG. 8, the step 501 can be executed after the step 201.

[0264] The step 501 is that, in the case of determining that the first information element is abnormal, the UE performs cell reselection.

[0265] In some embodiments of the present application, after receiving the first downlink NAS message, if it is determined that the UE is not in the first mode, the UE can determine that the first information element in the first downlink NAS message is abnormal, and then the UE can perform cell reselection and re-perform NAS access.

[0266] In some embodiments of the present application, after receiving the first downlink NAS message, if it is determined that the first information element is not within the reasonable value range of the second information element, the UE can determine that the first information element in the first downlink NAS message is abnormal, and then the UE can perform cell reselection and re-perform NAS access.

[0267] In this way, when the first information element in the first downlink NAS message is abnormal, it means that the UE is currently accessing an abnormal SAT or a pseudo base station, and therefore the UE can leave the current base station by reselecting a cell to obtain normal S&F services.

[0268] It should be noted that the present application only takes the step 501 executed after the step 201 as an example, and the step 501 can also be executed after the step 301 or the step 402. The embodiments of the present application do not limit this.

[0269] In some embodiments of the present application, in combination with FIG. 3, as shown in FIG. 9, before the step 201, the communication method provided by the embodiments of the present application can further include the following step 601.

[0270] Step 601, the UE sends a first uplink NAS message.

[0271] In the embodiments of the present application, the first uplink NAS message includes first capability information, and the first capability information is used to indicate that the UE supports a first mode.

[0272] In some embodiments of the present application, after the UE decides to use the store-and-forward mode, the UE can select a communication device according to receiving a broadcast message including indication information from the communication device, and send the first uplink NAS message to the communication device.

[0273] In some embodiments of the present application, the indication information is used to indicate that the communication device supports the store-and-forward mode.

[0274] In some embodiments of the present application, the first mode is a store-and-forward mode, i.e., S&F mode.

[0275] In some embodiments of the present application, the first uplink NAS message can include any one of the following: an Attach request message, a TAU request message.

[0276] In some embodiments of the present application, when the first uplink NAS message does not include the first capability information, the first downlink NAS message does not include the first information element.

[0277] FIG. 10 is a flow diagram of a communication method according to an embodiment of the present application. As shown in FIG. 10, the communication method can include the following step 701.

[0278] Step 701, the mobility management device sends a second downlink NAS message with security protection to the UE.

[0279] In some embodiments of the present application, the mobility management device can be understood as the ground network element described above.

[0280] In the embodiments of the present application, the second downlink NAS message includes a second information element.

[0281] In the embodiments of the present application, the second information element is used to determine whether the first information element is abnormal, and the first information element is used for the first mode.

[0282] In some embodiments of the present application, the first mode is a store-and-forward mode.

[0283] In some embodiments of the present application, the second information element can include at least one of the following: a reasonable time range, a second communication device list.

[0284] It should be noted that the detailed steps of the second information element can be referred to the description in the above embodiments, which will not be repeated here.

[0285] The communication method provided by the embodiments of the present application can improve the reliability of communication.

[0286] In some embodiments of the present application, as shown in FIG. 11, before step 701, the communication method provided by the embodiments of the present application can further include the following step 702.

[0287] Step 702: The mobility management device receives the uplink NAS message sent by the UE for requesting the second information element.

[0288] Specifically, the mobility management device receiving the uplink NAS message sent by the UE for requesting the second information element and sending the second downlink NAS message with security protection to the UE can include the following two ways.

[0289] Way one (the mobility management device receives the uplink NAS message sent by the UE for requesting the second information element through the communication device SAT, and sends the second downlink NAS message with security protection to the UE through the communication device):

[0290] It can be understood that the UE can send the uplink NAS message for requesting the second information element to the communication device, and the communication device can forward the uplink NAS message to the mobility management device after receiving the uplink NAS message. Subsequently, the mobility management device can send the second downlink NAS message carrying the second information element to the communication device after receiving the uplink NAS message, and then the communication device forwards the second downlink NAS message to the UE.

[0291] Way two (the mobility management device receives the uplink NAS message sent by the UE for requesting the second information element through the ground network, and sends the second downlink NAS message with security protection to the UE through the ground network):

[0292] It can be understood that the UE can send the uplink NAS message for requesting the second information element to the ground network, and the ground network can forward the uplink NAS message to the mobility management device after receiving the uplink NAS message. Subsequently, the mobility management device can send the second downlink NAS message carrying the second information element to the ground network after receiving the uplink NAS message, and then the ground network forwards the second downlink NAS message to the UE.

[0293] It should be noted that the detailed steps of receiving, by the mobility management device, the uplink NAS message for requesting the second information element sent by the UE, and sending, by the mobility management device, the second downlink NAS message carrying the second information element to the UE can be referred to the description in the above embodiments, and will not be described here.

[0294] In some embodiments of the application, the communication method provided by the embodiments of the application can further include the following step 703.

[0295] For example, in combination with FIG. 11, as shown in FIG. 12, step 703 can be performed after step 702.

[0296] In step 703, the mobility management device determines the second information element according to the location of the UE.

[0297] In some embodiments of the application, the second information element is an information element corresponding to the location information of the location where the UE currently locates.

[0298] In some embodiments of the application, the uplink NAS message for requesting the second information element can include the location information of the location where the UE currently locates.

[0299] In some embodiments of the application, after receiving the uplink NAS message for requesting the second information element, the mobility management device can determine the second information element corresponding to the location information according to the location information carried in the uplink NAS message or generated by the communication device, and carry the second information element corresponding to the location information in the second downlink NAS message when sending the second downlink NAS message to the UE.

[0300] In some embodiments of the application, the second downlink NAS message further includes the location information of the location where the UE currently locates, and the location information corresponds to the second information element.

[0301] In some embodiments of the application, the second downlink NAS message includes at least two information elements, and each information element corresponds to one location information.

[0302] It can be understood that the mobility management device does not directly carry the second information element corresponding to the location information of the location where the UE currently locates in the second downlink NAS message to the UE, but carries at least two information elements preconfigured on the mobility management device and the location information corresponding to the at least two information elements in the second downlink NAS message to the UE. Subsequently, the UE can obtain the location information according to the current location when receiving the second downlink NAS message, and then determine the information element corresponding to the location information of the UE from the at least two information elements as the second information element according to the location information.

[0303] It should be noted that the detailed steps of determining the second information element by the mobility management device according to the location of the UE can be referred to the description in the above embodiments, and will not be described here.

[0304] In some embodiments of the application, as shown in FIG. 13, the communication method provided by the embodiments of the application can include the following steps 801 to 804.

[0305] Step 801, the UE sends an uplink NAS message for requesting the second information element to the mobility management device.

[0306] Step 802, the mobility management device receives the uplink NAS message for requesting the second information element sent by the UE.

[0307] Step 803, the mobility management device sends a second downlink NAS message carrying the second information element to the UE.

[0308] Step 804, the UE receives the second downlink NAS message carrying the second information element sent by the mobility management device.

[0309] It should be noted that the related description of steps 801 to 804 can be referred to the content in the above embodiments, and will not be described here.

[0310] In some embodiments of the application, in a normal scenario, as shown in FIG. 14, the communication method provided by the embodiments of the application can include the following steps S51 to S55.

[0311] S51, the UE sends an uplink NAS message to the ground network.

[0312] S52, the ground network receives the uplink NAS message sent by the UE.

[0313] S53, the ground network sends a NAS Reject message to the UE.

[0314] S54, the UE receives the NAS Reject message sent by the ground network.

[0315] S55, in a case where it is determined that the UE is not in the S&F mode, the UE determines that the S&F information element in the NAS Reject message is abnormal, and the UE ignores the S&F information element.

[0316] It should be noted that the related description of steps S51 to S55 can be referred to the content in the above embodiments, and will not be described here.

[0317] In some embodiments of the application, in an S&F scenario, as shown in FIG. 15, the communication method provided by the embodiments of the application can include the following steps S61 to S65.

[0318] S61, the UE sends an uplink NAS message to the SAT.

[0319] S62, the SAT receives the uplink NAS message sent by the UE.

[0320] S63, the SAT sends a NAS Reject message to the UE.

[0321] S64, the UE receives the NAS Reject message sent by the SAT.

[0322] S65, the UE determines that the S&F information element in the NAS Reject message is abnormal according to the stored second information element, and the UE ignores the S&F information element.

[0323] It should be noted that the related description of steps S61 to S65 can refer to the content in the above embodiments, which will not be described here.

[0324] The communication method provided by the embodiment of the application can be executed by a communication device. In the embodiment of the application, the communication device is taken as an example to illustrate the communication device provided by the embodiment of the application.

[0325] The communication device provided by the embodiment of the application can be a communication device or a component in the communication device, for example, a chip. The communication device can be a terminal, a network side device or a server, etc. For example, the terminal can be the UE described above, and can include but not limited to the types of the terminal 11 described above. The network side device can be the mobility management device described above, and can include but not limited to the types of the network side device 12 described above, which is not limited in the embodiment of the application.

[0326] The communication apparatus includes a receiving module, a sending module and a processing module. The receiving module, the sending module and the processing module can be implemented by software or hardware. When implemented by hardware, the processing module can be implemented by a processor, which can include a general processor, a special purpose processor, etc., such as a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), an artificial intelligent (AI) processor, a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a network processor (NP), a field programmable gate array (FPGA) or other programmable logic device, a gate circuit, a transistor, a discrete hardware component, etc. The receiving module and the sending module can be implemented by a communication interface, which can include one or more of a transceiver, a pin, a circuit, a bus, a radio frequency unit, etc.

[0327] Specifically, referring to FIG. 16, when the communication apparatus is a UE or a component in the UE, the communication apparatus 800 includes a receiving module 801 configured to receive a first downlink NAS message, the first downlink NAS message including a first information element, the first information element being used for a first mode; and a processing module 802 configured to ignore the first information element in a case that the first information element is abnormal.

[0328] The communication apparatus provided by the embodiments of the present application can determine whether the first information element used for the first mode in the first downlink NAS message is abnormal after receiving the first downlink NAS message, ignore the first information element in a case that the first information element is abnormal, and not directly send an uplink NAS message according to the first information element, thereby avoiding the security problem existing in directly sending the uplink NAS message according to the first information element, and improving the reliability of communication. The communication apparatus can determine whether the first information element used for the first mode in the first downlink NAS message is abnormal after receiving the first downlink NAS message, ignore the first information element in a case that the first information element is abnormal, and not directly perform a subsequent operation according to the first information element, thereby avoiding the security problem existing in directly performing the subsequent operation according to the first information element, and improving the reliability of communication.

[0329] In some possible implementation manners, the first downlink NAS message is a NAS reject message, and the NAS reject message is used to indicate that the rejection in the first mode occurs, and the first downlink NAS message does not have security protection.

[0330] In some possible implementation manners, the first information element includes at least one of the following: a rejection reason value, a rejection duration, and a first communication device list, wherein the rejection reason value is used to indicate a reason for the rejection in the first mode, the rejection duration is used to indicate a duration for which the UE needs to wait before sending an uplink NAS message, and the first communication device list includes an identifier of at least one communication device that supports the first mode.

[0331] In some possible implementation manners, the processing module 802 is further configured to, in the case that the first information element is abnormal, ignore the first information element, and before determining that the first information element is abnormal, determine that the UE is not in the first mode.

[0332] In some possible implementation manners, the processing module 802 is specifically configured to, in the case that the first condition is met, determine that the UE is not in the first mode, and determine that the first information element is abnormal.

[0333] The first condition includes at least one of the following:

[0334] The UE receives a broadcast message from the communication device, and the broadcast message does not include indication information used to indicate that the communication device supports the first mode.

[0335] The UE determines, according to a local setting, that the UE is not in the first mode.

[0336] The uplink NAS message sent by the UE does not include first capability information used to indicate that the UE supports the first mode, or the uplink NAS message sent by the UE includes second capability information used to indicate that the UE does not support the first mode.

[0337] In some possible implementation manners, the processing module 802 is further configured to, in the case that the first information element is abnormal, ignore the first information element, and before determining that the first information element is abnormal, obtain a second information element, and determine that the first information element is abnormal according to the second information element, wherein the second information element is preconfigured on the UE or obtained from a message having security protection.

[0338] In some possible implementation manners, the second information element is obtained from the message having security protection, and the receiving module 801 is specifically configured to receive a second downlink NAS message, the second downlink NAS message is the message having security protection, and the second downlink NAS message includes the second information element.

[0339] In a possible implementation, the communication apparatus provided by the embodiment of the application further includes a sending module; and the sending module is configured to send an uplink NAS message for requesting the second information element before the receiving module 801 receives the second downlink NAS message.

[0340] In a possible implementation, the second downlink NAS message further includes location information of a location where the UE currently stays, the location information corresponding to the second information element; and the processing module 802 is specifically configured to obtain the location information according to the location where the UE currently stays, and obtain the second information element from the second downlink NAS message according to the location information.

[0341] In a possible implementation, the communication apparatus provided by the embodiment of the application further includes a sending module; and the sending module is configured to send the uplink NAS message according to the second information element in the case that the first information element is abnormal.

[0342] In a possible implementation, the first information element includes at least one of the following: a rejection duration and a first communication device list, the rejection duration being used to indicate a duration for which the UE needs to wait before sending the uplink NAS message, and the first communication device list including an identifier of at least one communication device that supports the first mode; and the processing module 802 is specifically configured to determine that the first information element is abnormal in the case that the first information element satisfies a second condition.

[0343] In a possible implementation, the second condition includes at least one of the following:

[0344] The rejection duration is not within a reasonable duration range included in the second information element;

[0345] The first communication device list includes an identifier of a communication device other than a second communication device list included in the second information element.

[0346] In a possible implementation, the communication apparatus provided by the embodiment of the application further includes a sending module; and the sending module is configured to send the uplink NAS message to one of the communication devices in the second communication device list after waiting for a first duration in the case that the first information element is abnormal, the first duration being a lower limit value in the reasonable duration range.

[0347] In a possible implementation, the processing module 802 is further configured to perform cell reselection in the case that the first information element is abnormal.

[0348] In a possible implementation, the communication apparatus provided by the embodiment of the application further includes a sending module; and the sending module is configured to send a first uplink NAS message before the receiving module 801 receives a first downlink NAS message, the first uplink NAS message including first capability information, the first capability information being used to indicate that the UE supports the first mode.

[0349] In some possible implementation manners, the first mode is a store-and-forward mode.

[0350] Referring to FIG. 17, when the communication apparatus is a mobility management device or a component in the mobility management device, the communication apparatus 900 includes a sending module 901 configured to send, to a UE, a second downlink non-access stratum (NAS) message with security protection, the second downlink NAS message including a second information element; and the second information element is used to determine whether a first information element for a first mode is abnormal.

[0351] The communication apparatus provided in the embodiments of the present application can send, to a UE, a second downlink NAS message with security protection and including a second information element, so that the UE can determine, after receiving a first downlink NAS message, whether a first information element for a first mode in the first downlink NAS message is abnormal through the second information element, and in the case that the first information element is abnormal, the UE ignores the first information element and does not directly perform a subsequent operation according to the first information element, thereby avoiding the security problem existing in directly performing the subsequent operation according to the first information element, and improving the reliability of communication.

[0352] In some possible implementation manners, the communication apparatus provided in the embodiments of the present application further includes a receiving module configured to receive, before the sending module 901 sends, to the UE, the second downlink NAS message with security protection, an uplink NAS message sent by the UE and used to request the second information element.

[0353] In some possible implementation manners, the second information element includes at least one of the following: a reasonable time range and a second communication device list.

[0354] In some possible implementation manners, the communication apparatus provided in the embodiments of the present application further includes a processing module configured to determine the second information element according to a location of the UE.

[0355] In some possible implementation manners, the second downlink NAS message further includes location information of a location currently located by the UE, and the location information corresponds to the second information element.

[0356] In some possible implementation manners, the first mode is a store-and-forward mode.

[0357] The communication apparatus provided in the embodiments of the present application can implement each process achieved by the method embodiments and achieve the same technical effects. To avoid repetition, details are not described herein.

[0358] As shown in FIG. 18, the embodiment of the present application further provides a communication device 2000, comprising a processor 2001 and a memory 2002, wherein the memory 2002 stores programs or instructions executable by the processor 2001, for example, when the communication device 2000 is a UE, the programs or instructions are executed by the processor 2001 to implement each step of the above-mentioned UE-side communication method embodiment and achieve the same technical effects. When the communication device 2000 is a mobility management device, the programs or instructions are executed by the processor 2001 to implement each step of the above-mentioned mobility management device-side communication method embodiment and achieve the same technical effects. To avoid repetition, details are not described herein.

[0359] The embodiment of the present application further provides a UE, comprising a processor and a communication interface, wherein the communication interface and the processor are coupled, and the processor is configured to run programs or instructions to implement the steps in the above-mentioned method embodiments. The UE embodiment corresponds to the above-mentioned UE-side method embodiment, and each implementation process and implementation manner of the above-mentioned method embodiment can be applied to the UE embodiment and achieve the same technical effects. The UE can be the communication device shown in FIG. 16. Specifically, FIG. 19 is a hardware structure schematic diagram of a UE according to the embodiment of the present application.

[0360] The UE 100 includes, but is not limited to, at least part of the following components: a radio frequency unit 101, a network module 102, an audio output unit 103, an input unit 104, a sensor 105, a display unit 106, a user input unit 107, an interface unit 108, a memory 109, and a processor 110, etc.

[0361] Those skilled in the art can understand that the UE 100 can further include a power supply (such as a battery) for supplying power to each component, and the power supply can be logically connected to the processor 110 through a power management system, so as to realize the functions of power management, such as charging, discharging, and power consumption management, through the power management system. The UE structure shown in FIG. 19 does not constitute a limitation on the UE, and the UE can include more or fewer components than the illustrated components, or combine certain components, or different component arrangements, which are not described herein.

[0362] It should be understood that in the embodiments of the present application, the input unit 104 can include a graphics processor 1041 and a microphone 1042, and the graphics processor 1041 processes image data of a still picture or a video obtained by an image capture device (such as a camera) in a video capture mode or an image capture mode. The display unit 106 can include a display panel 1061, which can be configured in the form of a liquid crystal display, an organic light-emitting diode, etc. The user input unit 107 includes at least one of a touch panel 1071 and other input devices 1072. The touch panel 1071 is also called a touch screen. The touch panel 1071 can include two parts of a touch detection device and a touch controller. The other input devices 1072 can include, but are not limited to, a physical keyboard, function keys (such as volume control keys, on-off keys, etc.), a trackball, a mouse, a joystick, etc., which will not be described here.

[0363] In the embodiments of the present application, after the radio frequency unit 101 receives the downlink data from the network side device, it can be transmitted to the processor 110 for processing; in addition, the radio frequency unit 101 can send uplink data to the network side device. Generally, the radio frequency unit 101 includes, but is not limited to, an antenna, an amplifier, a transceiver, a coupler, a low noise amplifier, a duplexer, etc.

[0364] The memory 109 can be used to store software programs or instructions and various data. The memory 109 can mainly include a first storage area storing programs or instructions and a second storage area storing data, wherein the first storage area can store an operating system, at least one application program or instruction required by a function (such as a sound playing function, an image playing function, etc.), and the like. In addition, the memory 109 can include a volatile memory or a non-volatile memory. The non-volatile memory can be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically EPROM (EEPROM), or a flash memory. The volatile memory can be a Random Access Memory (RAM), a Static RAM (SRAM), a Dynamic RAM (DRAM), a Synchronous DRAM (SDRAM), a Double Data Rate SDRAM (DDR SDRAM), an Enhanced SDRAM (ESDRAM), a Synch link DRAM (SLDRAM), and a Direct Rambus RAM (DRRAM). The memory 109 in the embodiments of the present application includes but is not limited to these and any other suitable types of memory.

[0365] The processor 110 can include one or more processing units; optionally, the processor 110 integrates an application processor and a modem processor, wherein the application processor mainly processes operations related to an operating system, a user interface, and an application program, and the modem processor mainly processes wireless communication signals, such as a baseband processor. It can be understood that the above-mentioned modem processor can also not be integrated into the processor 110.

[0366] The above-mentioned radio frequency unit 101 is configured to receive a first downlink NAS message, the first downlink NAS message including a first information element, and the first information element being used for a first mode.

[0367] The processor 110 is configured to ignore the first information element in a case where the first information element is abnormal.

[0368] The UE provided by the embodiments of the present application can determine whether the first information element for the first mode in the first downlink NAS message is abnormal after the UE receives the first downlink NAS message, and in the case that the first information element is abnormal, the first information element is ignored, and subsequent operations are not directly performed according to the first information element, thereby avoiding the security problem of directly performing subsequent operations according to the first information element, and improving the reliability of communication.

[0369] In some embodiments of the present application, the first downlink NAS message is a NAS rejection message, the NAS rejection message is used to indicate that rejection in the first mode occurs, and the first downlink NAS message does not have security protection.

[0370] In some embodiments of the present application, the first information element includes at least one of the following: a rejection reason value, a rejection duration, and a first communication device list; wherein the rejection reason value is used to indicate the reason for rejection in the first mode; the rejection duration is used to indicate the duration for which the UE needs to wait before sending an uplink NAS message; and the first communication device list includes an identifier of at least one communication device that supports the first mode.

[0371] In some embodiments of the present application, the processor 110 is further configured to, before ignoring the first information element in the case that the first information element is abnormal, determine that the first information element is abnormal in the case that the UE is not in the first mode.

[0372] In some embodiments of the present application, the processor 110 is specifically configured to, in the case that the first condition is met, determine that the UE is not in the first mode, so as to determine that the first information element is abnormal.

[0373] The first condition includes at least one of the following:

[0374] The UE receives a broadcast message from the communication device, and the broadcast message does not contain indication information, wherein the indication information is used to indicate that the communication device supports the first mode.

[0375] The UE determines that the UE is not in the first mode according to a local setting.

[0376] The uplink NAS message sent by the UE does not contain first capability information, and the first capability information is used to indicate that the UE supports the first mode; or the uplink NAS message sent by the UE contains second capability information, and the second capability information is used to indicate that the UE does not support the first mode.

[0377] In some embodiments of the present application, the processor 110 is further configured to, before ignoring the first information element in the case that the first information element is abnormal, obtain a second information element, and the second information element is preconfigured on the UE or obtained from a message with security protection; and determine that the first information element is abnormal according to the second information element.

[0378] In some embodiments of the present application, the second information element is obtained from the message with security protection, and the radio frequency unit 101 is specifically configured to receive a second downlink NAS message, the second downlink NAS message being the message with security protection, and the second downlink NAS message including the second information element.

[0379] In some embodiments of the present application, the radio frequency unit 101 is further configured to, before receiving the second downlink NAS message, send an uplink NAS message for requesting the second information element.

[0380] In some embodiments of the present application, the second downlink NAS message further includes location information of a current location of the UE, the location information corresponding to the second information element; and the processor 110 is specifically configured to obtain the location information according to the current location, and obtain the second information element from the second downlink NAS message according to the location information.

[0381] In some embodiments of the present application, the radio frequency unit 101 is further configured to, in the case that the first information element is abnormal, send the uplink NAS message according to the second information element.

[0382] In some embodiments of the present application, the first information element includes at least one of the following: a rejection duration and a first communication device list, the rejection duration being used to indicate a duration for which the UE needs to wait before sending the uplink NAS message, and the first communication device list including an identifier of at least one communication device that supports the first mode; and the processor 110 is specifically configured to, in the case that the first information element satisfies a second condition, determine that the first information element is abnormal.

[0383] The second condition includes at least one of the following:

[0384] The rejection duration is not within a reasonable duration range included in the second information element;

[0385] The first communication device list includes an identifier of a communication device other than a second communication device list included in the second information element.

[0386] In some embodiments of the present application, the radio frequency unit 101 is further configured to, in the case that the first information element is abnormal, send the uplink NAS message to one of the communication devices in the second communication device list after waiting for a first duration, the first duration being a lower limit value in the reasonable duration range.

[0387] In some embodiments of the present application, the processor 110 is further configured to, in the case that the first information element is abnormal, perform cell reselection.

[0388] In some embodiments of the present application, the radio frequency unit 101 is further configured to, before receiving the first downlink NAS message, send a first uplink NAS message, the first uplink NAS message including first capability information, the first capability information being used to indicate that the UE supports the first mode.

[0389] In some embodiments of the present application, the first mode is a store-and-forward mode.

[0390] It can be understood that the implementation process of each implementation mode mentioned in the embodiment can refer to the related description of the method embodiment and achieve the same or corresponding technical effects. To avoid repetition, it will not be described here.

[0391] The embodiment of the present application also provides a mobility management device, comprising a processor and a communication interface, the communication interface and the processor are coupled, and the processor is used to run programs or instructions to realize the steps of the above-mentioned method embodiment. The mobility management device embodiment corresponds to the above-mentioned mobility management device method embodiment, and each implementation process and implementation mode of the above-mentioned method embodiment can be applied to the mobility management device embodiment and can achieve the same technical effects.

[0392] Specifically, the embodiment of the present application also provides a mobility management device. As shown in FIG. 20, the mobility management device 3000 comprises a processor 3001, a network interface 3002 and a memory 3003. The mobility management device can be the communication device shown in FIG. 17. Wherein, the network interface 3002 is, for example, a common public radio interface (common public radio interface, CPRI).

[0393] Specifically, the mobility management device 3000 of the embodiment of the present application further comprises instructions or programs stored in the memory 3003 and executable on the processor 3001, and the processor 3001 invokes the instructions or programs in the memory 3003 to execute the method executed by each module shown in FIG. 17, and achieves the same technical effects. To avoid repetition, it will not be described here.

[0394] The network interface 3002 is configured to send the second downlink NAS message with security protection to the UE.

[0395] The embodiment of the present application also provides a readable storage medium, and the readable storage medium stores programs or instructions, which are executed by the processor to realize each process of the above-mentioned communication method embodiment and can achieve the same technical effects. To avoid repetition, it will not be described here.

[0396] The processor is the processor in the terminal in the above-mentioned embodiment. The readable storage medium comprises a computer readable storage medium, such as a computer readable only memory (computer readable only memory, ROM), a random access memory (random access memory, RAM), a magnetic disk or an optical disk, etc. In some examples, the readable storage medium can be a non-transient readable storage medium.

[0397] The embodiment of the present application further provides a chip, which comprises a processor and a communication interface, wherein the communication interface is coupled with the processor, the processor is used to run programs or instructions, realizes various processes of the communication method embodiment, and can achieve the same technical effects. To avoid repetition, details are not described herein.

[0398] It should be understood that the chip mentioned in the embodiment of the present application can also be referred to as a system chip, a system chip, a chip system or a system on chip, etc.

[0399] The embodiment of the present application further provides a computer program / program product, which is stored in a storage medium, and is executed by at least one processor to realize various processes of the communication method embodiment and achieve the same technical effects. To avoid repetition, details are not described herein.

[0400] The embodiment of the present application further provides a communication system, which comprises a UE and a mobility management device, wherein the UE can be used to execute the steps of the communication method on the UE side, and the mobility management device can be used to execute the steps of the communication method on the mobility management device side.

[0401] It should be noted that in this document, the terms "comprising", "containing", or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles or devices including a series of elements not only include those elements, but also include other elements not explicitly listed, or include elements inherent to such processes, methods, articles or devices. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to the order of performing functions as shown or discussed, and can also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method can be performed in an order different from the described order, and various steps can also be added, omitted or combined. In addition, the features described with reference to some examples can be combined in other examples. Through the description of the above embodiments, those skilled in the art can clearly understand that the above embodiment methods can be realized by means of computer software products and general hardware platforms as required, and of course, can also be realized by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.), and comprises a plurality of instructions for making the terminal or network side device execute the method described in each embodiment of the present application.

[0402] The embodiments of the present application are described above with reference to the accompanying drawings, but the present application is not limited to the above-described specific embodiments, and the above-described specific embodiments are merely illustrative, but not restrictive, and a person of ordinary skill in the art can make many forms of embodiments under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, and these embodiments all belong to the protection of the present application.

Claims

1. A communication method, the method comprising: receiving, by a user equipment (UE), a first downlink non-access stratum (NAS) message, the first downlink NAS message comprising a first information element (IE), the first IE being used for a first mode; ignoring, by the UE, the first IE in case that the first IE is abnormal.

2. The method of claim 1, wherein, the first downlink NAS message is a NAS reject message, the NAS reject message being used to indicate that a rejection in the first mode occurs, and the first downlink NAS message does not have security protection.

3. The method of claim 1 or 2, wherein, the first IE comprises at least one of: a rejection cause value, a rejection duration, and a first communication device list; the rejection cause value is used to indicate a cause of the rejection in the first mode; the rejection duration is used to indicate a duration that the UE needs to wait before sending an uplink NAS message; and the first communication device list comprises an identity of at least one communication device that supports the first mode.

4. The method of any one of claims 1 to 3, wherein, before the ignoring, by the UE, the first IE in case that the first IE is abnormal, the method further comprises: determining, by the UE, that the first IE is abnormal in case that the UE is not in the first mode.

5. The method of claim 4, wherein, the determining, by the UE, that the first IE is abnormal in case that the UE is not in the first mode, comprises: determining, by the UE, that the UE is not in the first mode to determine that the first IE is abnormal in case that a first condition is satisfied; the first condition comprises at least one of: receiving, by the UE, a broadcast message from a communication device, the broadcast message not comprising indication information that is used to indicate that the communication device supports the first mode; determining, by the UE, that the UE is not in the first mode according to a local setting; an uplink NAS message sent by the UE does not comprise first capability information that is used to indicate that the UE supports the first mode; or an uplink NAS message sent by the UE comprises second capability information that is used to indicate that the UE does not support the first mode.

6. The method of claim 1 or 2, wherein, before the ignoring, by the UE, the first IE in case that the first IE is abnormal, the method further comprises: obtaining, by the UE, a second IE, the second IE being pre-configured on the UE or obtained from a message having security protection; determining, by the UE, that the first IE is abnormal according to the second IE.

7. The method of claim 6, wherein, the second IE is obtained from the message having security protection, and the obtaining, by the UE, the second IE, comprises: receiving, by the UE, a second downlink NAS message, the second downlink NAS message being the message having security protection, and the second downlink NAS message comprising the second IE.

8. The method of claim 7, wherein, before the receiving, by the UE, the second downlink NAS message, the method further comprises: sending, by the UE, an uplink NAS message for requesting the second IE.

9. The method of claim 7 or 8, wherein, the second downlink NAS message further comprises location information of a location where the UE is currently located, the location information corresponding to the second IE. the obtaining, by the UE, the second IE, comprises: The UE obtains the location information according to a location where the UE is currently located, and obtains the second information element from the second downlink NAS message according to the location information.

10. The method of any one of claims 6-9, wherein, The method further comprises: In the case that the first information element is abnormal, the UE sends an uplink NAS message according to the second information element.

11. The method of any one of claims 6 to 10, wherein, The first information element comprises at least one of: a rejection duration and a first communication device list, the rejection duration being used to indicate a duration for which the UE needs to wait before sending an uplink NAS message, and the first communication device list comprising an identification of at least one communication device which supports the first mode; The UE determines that the first information element is abnormal according to the second information element, comprising: In the case that the first information element satisfies a second condition, the UE determines that the first information element is abnormal; The second condition comprises at least one of: The rejection duration is not within a reasonable duration range contained in the second information element; The first communication device list contains an identification of a communication device other than a second communication device list contained in the second information element.

12. The method of claim 11, wherein, The method further comprises: In the case that the first information element is abnormal, after waiting for a first duration, the UE sends an uplink NAS message to one of the communication devices in the second communication device list, the first duration being a lower limit value in the reasonable duration range.

13. The method of any one of claims 1 to 12, wherein, The method further comprises: In the case that the first information element is abnormal, the UE performs cell reselection.

14. The method of any one of claims 1 to 13, wherein, Before the UE receives the first downlink NAS message, the method further comprises: The UE sends a first uplink NAS message, the first uplink NAS message comprising first capability information, the first capability information being used to indicate that the UE supports the first mode.

15. The method according to any one of claims 1 to 14, wherein, The first mode is a store-and-forward mode.

16. A communication method, the method comprising: A mobility management device sends a second downlink non-access stratum (NAS) message with security protection to a user equipment (UE), the second downlink NAS message comprising a second information element; The second information element is used to determine whether a first information element is abnormal, the first information element being used for a first mode.

17. The method of claim 16, wherein, Before the mobility management device sends the second downlink NAS message with security protection to the UE, the method further comprises: The mobility management device receives an uplink NAS message sent by the UE for requesting the second information element.

18. The method of claim 16 or 17, wherein, The second information element comprises at least one of: a reasonable duration range and a second communication device list.

19. The method of any one of claims 16-18, wherein, The method further comprises: The mobility management device determines the second information element according to a location of the UE.

20. The method of any one of claims 16-18, wherein, The second downlink NAS message further comprises location information of the location where the UE is currently located, the location information corresponding to the second information element.

21. The method of any one of claims 16-20, wherein, The first mode is a store-and-forward mode.

22. A communications device, the device comprising: A receiving module and a processing module; The receiving module is configured to receive a first downlink non-access stratum (NAS) message, the first downlink NAS message comprising a first information element, the first information element being used for a first mode; The processing module is configured to, in the case that the first information element is abnormal, the UE ignoring the first information element.

23. The apparatus of claim 22, wherein, The first downlink NAS message is a NAS rejection message, the NAS rejection message is used to indicate that the rejection in the first mode occurs, and the first downlink NAS message has no security protection.

24. The apparatus of any one of claims 22-23, wherein, The processing module is further configured to, before ignoring the first information element in the case that the first information element is abnormal, determine that the first information element is abnormal in the case that the UE is not in the first mode.

25. The apparatus of claim 24, wherein, The processing module is specifically configured to, in the case that a first condition is met, determine that the UE is not in the first mode, so as to determine that the first information element is abnormal. The first condition includes at least one of the following: The UE receives a broadcast message from a communication device, and the broadcast message does not contain indication information used to indicate that the communication device supports the first mode. The UE determines that the UE is not in the first mode according to a local setting. An uplink NAS message sent by the UE does not contain first capability information used to indicate that the UE supports the first mode, or the uplink NAS message sent by the UE contains second capability information used to indicate that the UE does not support the first mode.

26. The apparatus of claim 22 or 23, wherein, The processing module is further configured to, before ignoring the first information element in the case that the first information element is abnormal, obtain a second information element, the second information element being preconfigured on the UE or obtained from a message with security protection; and determine the first information element to be abnormal according to the second information element. The second information element is obtained from a message with security protection, and the receiving module is specifically configured to receive a second downlink NAS message, the second downlink NAS message being the message with security protection, and the second downlink NAS message including the second information element.

27. The apparatus of claim 26, wherein, The apparatus further includes a sending module.

28. The apparatus of claim 27, wherein, The sending module is configured to send an uplink NAS message used to request the second information element before the receiving module receives the second downlink NAS message. The second downlink NAS message further includes location information of a location where the UE is currently located, the location information corresponding to the second information element.

29. The apparatus of claim 27 or 28, wherein, The processing module is specifically configured to obtain the location information according to the location where the UE is currently located, and obtain the second information element from the second downlink NAS message according to the location information. The apparatus further includes a sending module.

30. The apparatus of any one of claims 26-29, wherein, The sending module is configured to send an uplink NAS message according to the second information element in the case that the first information element is abnormal. The first information element includes at least one of the following: a rejection duration used to indicate a duration for which the UE needs to wait before sending an uplink NAS message, and a first communication device list including an identifier of at least one communication device used to indicate that the communication device supports the first mode.

31. The apparatus of any one of claims 26-30, wherein, The processing module is specifically configured to determine that the first information element is abnormal in the case that the first information element meets a second condition. The second condition includes at least one of the following: The rejection duration is not within a reasonable duration range contained in the second information element. ​ The first communication device list comprises an identity of a communication device other than the second communication device list comprised in the second information element.

32. The apparatus of claim 31, wherein, The apparatus further comprises a sending module; The sending module is configured to, in the case that the first information element is abnormal, send an uplink NAS message to one of the second communication devices after waiting for a first time length, the first time length being a lower limit value in the reasonable time length range.

33. The apparatus of any one of claims 22-32, wherein, The processing module is further configured to, in the case that the first information element is abnormal, perform cell reselection.

34. The apparatus of any one of claims 22-33, wherein, The apparatus further comprises a sending module, and the sending module is configured to send a first uplink NAS message before the receiving module receives a first downlink NAS message, the first uplink NAS message comprising first capability information, the first capability information being used to indicate that the UE supports the first mode.

35. A communications device, the device comprising: The sending module is configured to send a second downlink NAS message with security protection to a user equipment (UE), the second downlink NAS message comprising a second information element. The second information element is used to determine whether a first information element is abnormal, and the first information element is used for a first mode. The apparatus further comprises a receiving module, and the receiving module is configured to receive an uplink NAS message sent by the UE to request the second information element before the sending module sends the second downlink NAS message with security protection to the UE.

36. The apparatus of claim 35, wherein, The apparatus further comprises a processing module.

37. The apparatus of claim 35 or 36, wherein, The processing module is configured to determine the second information element according to a location of the UE. 38.A user equipment (UE) comprising a processor and a memory, the memory storing programs or instructions executable on the processor, the programs or instructions being executed by the processor to implement steps of the communication method according to any one of claims 1 to 15. 39.A mobility management device comprising a processor and a memory, the memory storing programs or instructions executable on the processor, the programs or instructions being executed by the processor to implement steps of the communication method according to any one of claims 16 to 21. 40.A readable storage medium, the readable storage medium storing programs or instructions, the programs or instructions being executed by a processor to implement steps of the communication method according to any one of claims 1 to 15, or to implement steps of the communication method according to any one of claims 16 to 21. 41.A computer program product stored in a storage medium, the computer program product being executed by at least one processor to implement steps of the communication method according to any one of claims 1 to 15, or to implement steps of the communication method according to any one of claims 16 to 21. ​

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