Communication methods, communication device, communication system, and storage medium

Abstract

The embodiments of the present disclosure relate to communication methods, a communication device, a communication system, and a storage medium. A communication method may be executed by a terminal, and the method comprises: according to a preconfigured first rule, determining a first key associated with a first candidate configuration, the first key being used for the terminal recovering a communication connection on the basis of the first candidate configuration. In the embodiments of the present disclosure, on the basis of the preconfigured first rule, the terminal and a network device determine a first key corresponding to a first candidate configuration used in a communication connection recovery process, such that the terminal and the network device can have consistent understanding of the first key, thereby increasing the probability of recovering communication connection, and improving the security of communication connection.

Description

Communication method, communication device, communication system, and storage medium TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of communication, and in particular, to a communication method, a communication device, a communication system, and a storage medium. BACKGROUND

[0002] In the fifth generation mobile communication technology new radio (NR), a network device can control a terminal to change a serving cell of the terminal based on a selected key in multiple candidate cells (or cell groups) to change the serving cell of the terminal based on L1 / L2-triggered mobility (LTM) technology triggered by layer 1 (L1) or layer 2 (L2) or a layer 3 mobility technology triggered based on a condition.

[0003] SUMMARY

[0004] In a process of communication connection failure of the terminal, the network device can not know the candidate cell configuration used by the terminal, and therefore, in a connection recovery process of the terminal, the terminal and the network device cannot reach a consistent understanding of the key associated with the candidate cell configuration used in the connection recovery process.

[0005] Embodiments of the present disclosure provide a communication method, a communication device, a communication system, and a storage medium.

[0006] According to a first aspect of embodiments of the present disclosure, a communication method is provided, which is performed by a communication device, and the method comprises: determining, according to a first rule, a first key associated with a first candidate configuration; and the first key is used for a terminal to perform communication connection recovery based on the first candidate configuration.

[0007] According to a second aspect of embodiments of the present disclosure, a communication method is provided, which is performed by a terminal, and the method comprises: sending first information, the first information being used to indicate a first key associated with a first candidate configuration; and the first key is used for the terminal to perform communication connection recovery based on the first candidate configuration.

[0008] According to a third aspect of embodiments of the present disclosure, a communication method is provided, which is performed by a network device, and the method comprises: receiving first information, the first information being used to indicate a first key associated with a first candidate configuration; and the first key is used for a terminal to perform communication connection recovery based on the first candidate configuration.

[0009] According to a fourth aspect of embodiments of the present disclosure, a communication device is provided, and the device comprises: a determination module configured to determine, according to a first rule, a first key associated with a first candidate configuration; and the first key is used for a terminal to perform communication connection recovery based on the first candidate configuration.

[0010] According to a fifth aspect of the embodiments of the present disclosure, a terminal is provided, including: a transceiver configured to send first information, the first information being used to indicate a first key associated with a first candidate configuration; the first key being used for the terminal to perform a communication connection recovery based on the first candidate configuration.

[0011] According to a sixth aspect of the embodiments of the present disclosure, a network device is provided, including: a transceiver configured to receive first information, the first information being used to indicate a first key associated with a first candidate configuration; the first key being used for a terminal to perform a communication connection recovery based on the first candidate configuration.

[0012] According to a seventh aspect of the embodiments of the present disclosure, a communication device is provided, including: one or more processors; and wherein the communication device is configured to perform the communication method of any one of the first aspect to the third aspect.

[0013] According to an eighth aspect of the embodiments of the present disclosure, a communication system is provided, including a terminal and a network device; the terminal is configured to implement the communication method of the first aspect or the second aspect; and the network device is configured to implement the communication method of the first aspect or the third aspect.

[0014] According to a ninth aspect of the embodiments of the present disclosure, a storage medium is provided, the storage medium storing instructions, when the instructions are executed on a communication device, causing the communication device to perform the communication method of any one of the first aspect to the third aspect.

[0015] According to a tenth aspect of the embodiments of the present disclosure, a computer program product is provided, including a computer program, when the computer program is executed by a processor, implementing the communication method of any one of the first aspect to the third aspect.

[0016] According to an eleventh aspect of the embodiments of the present disclosure, a computer program is provided, the computer program including code, when the code is executed by a processor, implementing the communication method of any one of the first aspect to the third aspect.

[0017] According to a twelfth aspect of the embodiments of the present disclosure, a chip or chip system is provided, including processing circuitry, the processing circuitry being configured to perform the communication method of any one of the first aspect to the third aspect.

[0018] According to the embodiments of the present disclosure, the terminal and the network device determine the first key corresponding to the first candidate configuration used in the communication connection recovery process based on the first rule, so that the understanding of the terminal and the network device about the first key is consistent, thereby increasing the probability of the communication connection recovery and improving the security of the communication connection. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following describes the drawings required for the embodiments, and the following drawings are only some embodiments of the present disclosure, and do not specifically limit the protection scope of the present disclosure.

[0020] FIG. 1 is an architecture schematic diagram of a communication system according to an embodiment of the present disclosure.

[0021] FIG. 2A is a first kind of interaction schematic diagram of a communication method according to an embodiment of the present disclosure.

[0022] FIG. 2B is a second kind of interaction schematic diagram of a communication method according to an embodiment of the present disclosure.

[0023] FIG. 2C is a third kind of interaction schematic diagram of a communication method according to an embodiment of the present disclosure.

[0024] FIG. 3A is a flow schematic diagram of a communication method performed by a terminal according to an embodiment of the present disclosure.

[0025] FIG. 3B is a flow schematic diagram of a communication method performed by a network device according to an embodiment of the present disclosure.

[0026] FIG. 4A is another flow schematic diagram of a communication method performed by a terminal according to an embodiment of the present disclosure.

[0027] FIG. 4B is another flow schematic diagram of a communication method performed by a network device according to an embodiment of the present disclosure.

[0028] FIG. 4C is still another flow schematic diagram of a communication method performed by a terminal according to an embodiment of the present disclosure.

[0029] FIG. 4D is still another flow schematic diagram of a communication method performed by a network device according to an embodiment of the present disclosure.

[0030] FIG. 5 is a structure schematic diagram of a communication device according to an embodiment of the present disclosure.

[0031] FIG. 6 is another structure schematic diagram of a communication device according to an embodiment of the present disclosure.

[0032] FIG. 7 is a structure schematic diagram of a chip according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] The embodiments of the present disclosure provide a communication method, a communication device, a communication system and a storage medium.

[0034] In a first aspect, the embodiments of the present disclosure provide a communication method, performed by a terminal, comprising: determining, according to a first rule, a first key associated with a first candidate configuration; the first key is used for the terminal to perform communication connection recovery based on the first candidate configuration.

[0035] In the embodiments of the present disclosure, the terminal and the network device can determine the first key corresponding to the first candidate configuration used in the communication connection recovery process based on the first rule, so that the understanding of the terminal and the network device about the first key can be consistent, thereby increasing the probability of communication connection recovery and improving the security of communication connection.

[0036] In some embodiments of the first aspect, in some embodiments, the first rule comprises one of the following: determining the first key from a key set configured by the network device; determining the first key based on a used key and a first value; determining the first key based on a used key in the key set configured by the network device and a second value.

[0037] In the embodiments of the present disclosure, the network device can configure a key set for the terminal, and the terminal can determine the first key from the key set. In this way, the network device can determine the key set to which the first key used by the terminal belongs, and then reach a consistent understanding with the terminal about the range of the first key. In addition, since the used key of the terminal is known to the network device, the network device can also reach a consistent understanding with the terminal about the first key in the case of determining the first key based on the used key and the first value or the second value.

[0038] In some embodiments of the first aspect, in some embodiments, the first candidate configuration is associated with a first key set, and the first rule further comprises one of the following: determining the first key from a key that has not been used in the first key set; determining the first key from a key that has not been used before the cell switching of the terminal in the first key set.

[0039] In some embodiments of the first aspect, in some embodiments, the first rule further comprises one of the following: determining the first key as a second key associated with a second candidate configuration; determining the first key from a second key set to which the second key belongs; wherein the second candidate configuration is associated with the second key set, and the second key is used for the cell switching of the terminal based on the second candidate configuration.

[0040] In some embodiments of the first aspect, in some embodiments, the first cell corresponding to the first candidate configuration and the second cell corresponding to the second candidate configuration belong to the same cell set; or the first cell corresponding to the first candidate configuration and the second cell corresponding to the second candidate configuration are the same; or the first candidate configuration and the second candidate configuration belong to the same configuration set.

[0041] In some embodiments of the first aspect, in some embodiments, the first candidate configuration is one of at least one candidate configuration, the at least one candidate configuration is associated with a third key set, and the third key set is used for the communication connection recovery process of the terminal; and the first rule further comprises: determining the first key from the third key set.

[0042] With reference to some embodiments of the first aspect, in some embodiments, the first rule further comprises: determining the first key from a fourth key set, wherein the fourth key set is associated with a serving cell used by the terminal before the communication connection recovery, and the fourth key set is used by the terminal to perform the communication connection recovery based on the first candidate configuration.

[0043] With reference to some embodiments of the first aspect, in some embodiments, the determining the first key comprises one of: determining the first key according to an arrangement order of keys in a sixth key set; or determining the first key according to a numerical value of keys in the sixth key set, wherein the sixth key set is one of: the first key set, the second key set, the third key set, or the fourth key set.

[0044] With reference to some embodiments of the first aspect, in some embodiments, the first rule further comprises one of: determining the first key based on a key last used by the terminal before the communication connection recovery and the first value; or determining the first key based on a key last used by the terminal before the cell switching and the first value.

[0045] With reference to some embodiments of the first aspect, in some embodiments, the first rule further comprises one of: determining the first key based on a key last used by the terminal before the communication connection recovery and the second value; or determining the first key based on a key last used by the terminal before the cell switching and the second value, wherein the fifth key set satisfies at least one of: the fifth key set is associated with the first candidate configuration; the fifth key set is associated with a second candidate configuration, and the second candidate configuration is used by the terminal to perform the cell switching; the fifth key set is associated with at least one candidate configuration, the first candidate configuration is one of the at least one candidate configuration, and the fifth key set is used by the terminal to perform the communication connection recovery; or the fifth key set is associated with a serving cell used by the terminal before the communication connection recovery, and the fifth key set is used by the terminal to perform the communication connection recovery based on the first candidate configuration.

[0046] With reference to some embodiments of the first aspect, in some embodiments, the method further comprises: sending the first information, wherein the first information is used to indicate the first key.

[0047] In the embodiments of the present disclosure, the terminal indicates the first key used by the terminal to the network device, so that the understanding of the first key by the terminal and the network device is consistent.

[0048] With reference to some embodiments of the first aspect, in some embodiments, the first information is carried in a first message, and the first message is one of: a connection reestablishment request message, a connection configuration complete message, or a medium access control layer message.

[0049] In a second aspect, the embodiments of the present disclosure provide a communication method, performed by a network device, comprising: determining a first key according to a first rule, the first key being used for a terminal to perform a communication connection recovery based on a first candidate configuration associated with the first key.

[0050] In some embodiments of the second aspect, in some embodiments, the first rule comprises one of: determining the first key from a key set configured by the network device; determining the first key based on a used key and a first value; and determining the first key based on a used key in the key set configured by the network device and a second value.

[0051] In some embodiments of the second aspect, in some embodiments, the first candidate configuration is associated with a first key set, and the first rule further comprises one of: determining the first key from a key that is not used in the first key set; and determining the first key from a key that is not used by the terminal before a cell switching.

[0052] In some embodiments of the second aspect, in some embodiments, the first rule further comprises one of: determining the first key as a second key associated with a second candidate configuration; and determining the first key from a second key set to which the second key belongs, wherein the second candidate configuration is associated with the second key set, and the second key is used for the terminal to perform a cell switching based on the second candidate configuration.

[0053] In some embodiments of the second aspect, in some embodiments, a first cell corresponding to the first candidate configuration and a second cell corresponding to the second candidate configuration belong to a same cell set, or the first cell and the second cell are the same, or the first candidate configuration and the second candidate configuration belong to a same configuration set.

[0054] In some embodiments of the second aspect, in some embodiments, the first candidate configuration is one of at least one candidate configuration, the at least one candidate configuration is associated with a third key set, the third key set is used for the terminal to perform a communication connection recovery process, and the first rule further comprises: determining the first key from the third key set.

[0055] In some embodiments of the second aspect, in some embodiments, the first rule further comprises: determining the first key from a fourth key set, wherein the fourth key set is associated with a serving cell used by the terminal before performing the communication connection recovery, and the fourth key set is used for the terminal to perform the communication connection recovery based on the first candidate configuration.

[0056] In some embodiments of the second aspect, in some embodiments, the determining the first key comprises one of the following: determining the first key according to an arrangement order of the keys in a sixth key set; determining the first key according to a numerical value of the keys in the sixth key set; wherein the sixth key set is one of the following: the first key set, the second key set, the third key set, the fourth key set.

[0057] In some embodiments of the second aspect, in some embodiments, the first rule further comprises one of the following: determining the first key based on a key used by the terminal last time and the first value; determining the first key based on a key used by the terminal before the cell switching and the second value.

[0058] In some embodiments of the second aspect, in some embodiments, the first rule further comprises one of the following: determining the first key based on a key used by the terminal last time in a fifth key set and the second value; determining the first key based on a key used by the terminal before the cell switching in the fifth key set and the second value; wherein the fifth key set satisfies at least one of the following: the fifth key set is associated with the first candidate configuration; the fifth key set is associated with a second candidate configuration, and the second candidate configuration is used for the cell switching of the terminal; the fifth key set is associated with at least one candidate configuration, the first candidate configuration is one of the at least one candidate configuration, and the fifth key set is used for the communication connection recovery of the terminal; the fifth key set is associated with a serving cell used before the communication connection recovery of the terminal, and the fifth key set is used for the communication connection recovery of the terminal based on the first candidate configuration.

[0059] In some embodiments of the second aspect, in some embodiments, the method further comprises: receiving the first information, wherein the first information is used to indicate the first key.

[0060] In some embodiments of the second aspect, in some embodiments, the first information is carried in a first message, and the first message is one of the following: a connection reestablishment request message, a connection configuration completion message, and a medium access control layer message.

[0061] In the third aspect, the embodiments of the present disclosure provide a communication method, which is performed by a terminal and comprises: sending first information, wherein the first information is used to indicate a first key associated with a first candidate configuration, and the first key is used for communication connection recovery of the terminal based on the first candidate configuration.

[0062] In some embodiments of the third aspect, in some embodiments, the first rule comprises one of the following: determining the first key from a key set configured by a network device; determining the first key based on a used key and a first value; determining the first key based on a used key in a key set configured by the network device and a second value.

[0063] In some embodiments of the third aspect, in some embodiments, the first candidate configuration is associated with a first set of keys, and the first rule further comprises one of: determining the first key from a key in the first set of keys that has not been used; and determining the first key from a key in the first set of keys that has not been used before the cell handover of the terminal.

[0064] In some embodiments of the third aspect, in some embodiments, the first rule further comprises one of: determining the first key as a first key associated with a second candidate configuration; and determining the first key from a first set of keys to which the first key belongs; wherein the second candidate configuration is associated with the first set of keys, and the first key is used for the cell handover of the terminal based on the second candidate configuration.

[0065] In some embodiments of the third aspect, in some embodiments, the first cell corresponding to the first candidate configuration and the second cell corresponding to the second candidate configuration belong to a same set of cells; or the first cell corresponding to the first candidate configuration and the second cell corresponding to the second candidate configuration are the same; or the first candidate configuration and the second candidate configuration belong to a same set of configurations.

[0066] In some embodiments of the third aspect, in some embodiments, the first candidate configuration is one of at least one candidate configuration, the at least one candidate configuration is associated with a first set of keys, and the first set of keys is used for the communication connection recovery procedure of the terminal; and the first rule further comprises determining the first key from the first set of keys.

[0067] In some embodiments of the third aspect, in some embodiments, the first rule further comprises determining the first key from a fourth set of keys; wherein the fourth set of keys is associated with a serving cell used before the communication connection recovery of the terminal, and the fourth set of keys is used for the communication connection recovery of the terminal based on the first candidate configuration.

[0068] In some embodiments of the third aspect, in some embodiments, determining the first key comprises one of: determining the first key according to an arrangement order of keys in a sixth set of keys; and determining the first key according to a numerical value of keys in the sixth set of keys; wherein the sixth set of keys is one of: the first set of keys, the first set of keys, the first set of keys, and the fourth set of keys.

[0069] In some embodiments of the third aspect, in some embodiments, the first rule further comprises one of: determining the first key based on a key last used by the terminal and a first value; and determining the first key based on a key used before the cell handover of the terminal and the first value.

[0070] In some embodiments of the third aspect, in some embodiments, the first rule further comprises one of the following: determining the first key based on a key in the fifth key set that was last used by the terminal before the cell switch and the second value; determining the first key based on a key in the fifth key set that was last used by the terminal before the cell switch; wherein the fifth key set satisfies at least one of the following: the fifth key set is associated with the first candidate configuration; or the fifth key set is associated with a second candidate configuration, the second candidate configuration being used for the cell switch by the terminal; or the fifth key set is associated with at least one candidate configuration, the first candidate configuration being one of the at least one candidate configuration, and the fifth key set being used for the communication connection recovery by the terminal; or the fifth key set is associated with a serving cell used by the terminal before the communication connection recovery, and the fifth key set being used for the communication connection recovery by the terminal based on the first candidate configuration.

[0071] In some embodiments of the third aspect, in some embodiments, the first information is carried in a first message, the first message being a connection reestablishment request message, or a connection configuration complete message, or a medium access control layer message.

[0072] In a fourth aspect, the embodiments of the present disclosure provide a communication method, implemented by a network device, the method comprising: receiving first information, the first information being used to indicate a first key associated with a first candidate configuration; the first key being used for a communication connection recovery by a terminal based on the first candidate configuration.

[0073] In some embodiments of the fourth aspect, in some embodiments, the first rule comprises one of the following: determining the first key from a key set configured by the network device; determining the first key based on a used key and a first value; determining the first key based on a used key in a key set configured by the network device and a second value.

[0074] In some embodiments of the fourth aspect, in some embodiments, the first candidate configuration is associated with a first key set, and the first rule further comprises one of the following: determining the first key from a key in the first key set that has not been used by the terminal; determining the first key from a key in the first key set that has not been used by the terminal before the cell switch.

[0075] In some embodiments of the fourth aspect, in some embodiments, the first rule further comprises one of the following: determining the first key as a first key associated with a second candidate configuration; determining the first key from a first key set to which the first key belongs; wherein the second candidate configuration is associated with the first key set, and the first key is used for a cell switch by the terminal based on the second candidate configuration.

[0076] In some embodiments of the fourth aspect, in some embodiments, the first candidate configuration corresponds to a first cell and the second candidate configuration corresponds to a second cell, and the first cell and the second cell belong to a same cell set; or, the first cell and the second cell are the same; or, the first candidate configuration and the second candidate configuration belong to a same configuration set.

[0077] In some embodiments of the fourth aspect, in some embodiments, the first candidate configuration is one of at least one candidate configuration, the at least one candidate configuration is associated with a first key set, and the first key set is used by the terminal to perform the communication connection recovery procedure; and the first rule further comprises: determining the first key from the first key set.

[0078] In some embodiments of the fourth aspect, in some embodiments, the first rule further comprises: determining the first key from a fourth key set; and the fourth key set is associated with a serving cell used by the terminal before the communication connection recovery, and the fourth key set is used by the terminal to perform the communication connection recovery based on the first candidate configuration.

[0079] In some embodiments of the fourth aspect, in some embodiments, the determining the first key comprises one of: determining the first key according to an arrangement order of the keys in a sixth key set; or, determining the first key according to a numerical value of the keys in the sixth key set; and the sixth key set is one of: the first key set, the first key set, the first key set, or the fourth key set.

[0080] In some embodiments of the fourth aspect, in some embodiments, the first rule further comprises one of: determining the first key based on a key last used by the terminal and a first value; or, determining the first key based on a key last used by the terminal before the cell switching and a first value.

[0081] In some embodiments of the fourth aspect, in some embodiments, the first rule further comprises one of: determining the first key based on a key last used by the terminal from a fifth key set and a second value; or, determining the first key based on a key last used by the terminal before the cell switching from the fifth key set and a second value; and the fifth key set satisfies at least one of: the fifth key set is associated with the first candidate configuration; or, the fifth key set is associated with a second candidate configuration, and the second candidate configuration is used by the terminal to perform the cell switching; or, the fifth key set is associated with at least one candidate configuration, the first candidate configuration is one of the at least one candidate configuration, and the fifth key set is used by the terminal to perform the communication connection recovery; or, the fifth key set is associated with a serving cell used by the terminal before the communication connection recovery, and the fifth key set is used by the terminal to perform the communication connection recovery based on the first candidate configuration.

[0082] In some embodiments of the fourth aspect, in some embodiments, the first information is carried in a first message, and the first message is a connection reestablishment request message, or a connection configuration complete message, or a medium access control layer message.

[0083] In the fifth aspect, the embodiments of the present disclosure provide a terminal, comprising: a determining module configured to determine a first key associated with a first candidate configuration according to a first rule; the first key is used for the terminal to perform a communication connection recovery based on the first candidate configuration.

[0084] In some embodiments of the fifth aspect, in some embodiments, the first rule comprises one of the following: determining the first key from a key set configured by a network device; determining the first key based on a used key and a first value; determining the first key based on a used key in the key set configured by the network device and a second value.

[0085] In some embodiments of the fifth aspect, in some embodiments, the first candidate configuration is associated with a first key set, and the first rule further comprises one of the following: determining the first key from a key that has not been used in the first key set; determining the first key from a key that has not been used before a cell switching of the terminal in the first key set.

[0086] In some embodiments of the fifth aspect, in some embodiments, the first rule further comprises one of the following: determining a second key associated with a second candidate configuration as the first key; determining the first key from a second key set to which the second key belongs; wherein the second candidate configuration is associated with the second key set, and the second key is used for the terminal to perform a cell switching based on the second candidate configuration.

[0087] In some embodiments of the fifth aspect, in some embodiments, a first cell corresponding to the first candidate configuration and a second cell corresponding to the second candidate configuration belong to a same cell set; or the first cell corresponding to the first candidate configuration and the second cell corresponding to the second candidate configuration are the same; or the first candidate configuration and the second candidate configuration belong to a same configuration set.

[0088] In some embodiments of the first aspect, in some embodiments, the first candidate configuration is one of at least one candidate configuration, the at least one candidate configuration is associated with a third key set, the third key set is used for the terminal to perform a communication connection recovery process, and the first rule further comprises: determining the first key from the third key set.

[0089] In some embodiments of the fifth aspect, in some embodiments, the first rule further comprises: determining the first key from a fourth key set; wherein the fourth key set is associated with a serving cell used by the terminal before performing a communication connection recovery, and the fourth key set is used for the terminal to perform the communication connection recovery based on the first candidate configuration.

[0090] In some embodiments of the fifth aspect, in some embodiments, the determining the first key comprises one of: determining the first key according to an arrangement order of the keys in a sixth key set; determining the first key according to a numerical value of the keys in the sixth key set; wherein the sixth key set is one of: the first key set, the second key set, the third key set, the fourth key set.

[0091] In some embodiments of the fifth aspect, in some embodiments, the first rule further comprises one of: determining the first key based on a key used by the terminal last time and the first value; determining the first key based on a key used by the terminal before the cell switching and the first value.

[0092] In some embodiments of the fifth aspect, in some embodiments, the first rule further comprises one of: determining the first key based on a key used by the terminal last time in a fifth key set and the second value; determining the first key based on a key used by the terminal before the cell switching in the fifth key set and the second value; wherein the fifth key set satisfies at least one of: the fifth key set is associated with the first candidate configuration; the fifth key set is associated with a second candidate configuration, the second candidate configuration is used for the cell switching of the terminal; the fifth key set is associated with at least one candidate configuration, the first candidate configuration is one of the at least one candidate configuration, and the fifth key set is used for the communication connection recovery of the terminal; the fifth key set is associated with a serving cell used before the communication connection recovery of the terminal, and the fifth key set is used for the communication connection recovery of the terminal based on the first candidate configuration.

[0093] In some embodiments of the fifth aspect, in some embodiments, the terminal further comprises: a transceiver configured to send the first information, the first information being used to indicate the first key.

[0094] In some embodiments of the fifth aspect, in some embodiments, the first information is carried in a first message, the first message being one of: a connection reestablishment request message, a connection configuration complete message, and a medium access control layer message.

[0095] In the sixth aspect, the embodiments of the present disclosure provide a network device, comprising: a determining module configured to determine a first key according to a first rule; the first key being used for a communication connection recovery of a terminal based on a first candidate configuration associated with the first key.

[0096] In some embodiments of the sixth aspect, in some embodiments, the first rule comprises one of: determining the first key from a key set configured by the network device; determining the first key based on a used key and the first value; determining the first key based on a used key in the key set configured by the network device and the second value.

[0097] In some embodiments of the sixth aspect, in some embodiments, the first candidate configuration is associated with a first set of keys, and the first rule further comprises one of: determining the first key from a key in the first set of keys that has not been used; and determining the first key from a key in the first set of keys that has not been used before the cell handover of the terminal.

[0098] In some embodiments of the sixth aspect, in some embodiments, the first rule further comprises one of: determining the first key as a second key associated with a second candidate configuration; and determining the first key from a second set of keys to which the second key belongs, wherein the second candidate configuration is associated with the second set of keys, and the second key is used for the cell handover of the terminal based on the second candidate configuration.

[0099] In some embodiments of the sixth aspect, in some embodiments, the first candidate configuration corresponds to a first cell and the second candidate configuration corresponds to a second cell, wherein the first cell and the second cell belong to a same set of cells, or the first cell and the second cell are the same, or the first candidate configuration and the second candidate configuration belong to a same set of configurations.

[0100] In some embodiments of the sixth aspect, in some embodiments, the first candidate configuration is one of at least one candidate configuration, the at least one candidate configuration is associated with a third set of keys, and the third set of keys is used for a communication connection recovery procedure of the terminal, and the first rule further comprises determining the first key from the third set of keys.

[0101] In some embodiments of the sixth aspect, in some embodiments, the first rule further comprises determining the first key from a fourth set of keys, wherein the fourth set of keys is associated with a serving cell used by the terminal before the communication connection recovery, and the fourth set of keys is used for the communication connection recovery of the terminal based on the first candidate configuration.

[0102] In some embodiments of the sixth aspect, in some embodiments, determining the first key comprises one of: determining the first key according to an arrangement order of keys in a sixth set of keys; and determining the first key according to a numerical value of keys in the sixth set of keys, wherein the sixth set of keys is one of: the first set of keys, the second set of keys, the third set of keys, and the fourth set of keys.

[0103] In some embodiments of the sixth aspect, in some embodiments, the first rule further comprises one of: determining the first key based on a key last used by the terminal and a first value; and determining the first key based on a key used by the terminal before the cell handover and the first value.

[0104] In some embodiments combined with the sixth aspect, in some embodiments, the first rule further comprises one of the following: determining the first key based on a key in the fifth key set that was last used by the terminal before the cell switch and the second value; determining the first key based on a key in the fifth key set that was last used by the terminal before the cell switch; wherein the fifth key set satisfies at least one of the following: the fifth key set is associated with the first candidate configuration; the fifth key set is associated with a second candidate configuration, the second candidate configuration is used for the cell switch by the terminal; the fifth key set is associated with at least one candidate configuration, the first candidate configuration is one of the at least one candidate configuration, and the fifth key set is used for the communication connection recovery by the terminal; the fifth key set is associated with a serving cell used by the terminal before the communication connection recovery, and the sixth key set is used for the communication connection recovery by the terminal based on the first candidate configuration.

[0105] In some embodiments combined with the sixth aspect, in some embodiments, the network device further comprises: a transceiver configured to receive the first information, the first information being used to indicate the first key.

[0106] In some embodiments combined with the sixth aspect, in some embodiments, the first information is carried in a first message, the first message being a connection reestablishment request message, or a connection configuration complete message, or a medium access control layer message.

[0107] In a seventh aspect, the embodiments of the present disclosure provide a communication device, comprising: one or more processors; wherein the communication device is configured to perform the communication method in any one of the first aspect, the second aspect, and the embodiments of the first aspect and the second aspect.

[0108] In an eighth aspect, the embodiments of the present disclosure provide a communication system, comprising: a terminal and a network device; the terminal is configured to implement the communication method in any one of the first aspect and the embodiments thereof; and the network device is configured to implement the communication method in any one of the second aspect and the embodiments thereof.

[0109] In a ninth aspect, the embodiments of the present disclosure provide a communication system, comprising: a terminal and a network device; the terminal is configured to implement the communication method in any one of the first aspect and the embodiments thereof; and the network device is configured to implement the communication method in any one of the second aspect and the embodiments thereof.

[0110] In a tenth aspect, the embodiments of the present disclosure provide a storage medium, the storage medium stores instructions, when the instructions are executed on a communication device, the communication device performs the communication method in any one of the first aspect, the second aspect, the third aspect, the fourth aspect, and the embodiments thereof.

[0111] In an eleventh aspect, the embodiments of the present disclosure provide a program product, which, when executed by a communication device, causes the communication device to perform the communication method according to any one of the first aspect, the second aspect, the third aspect, the fourth aspect, and the embodiments of the first aspect, the second aspect, the third aspect, and the fourth aspect.

[0112] In a twelfth aspect, the embodiments of the present disclosure provide a computer program, which, when running on a computer, causes the computer to perform the communication method according to any one of the first aspect, the second aspect, the third aspect, the fourth aspect, and the embodiments of the first aspect, the second aspect, the third aspect, and the fourth aspect.

[0113] In a thirteenth aspect, the embodiments of the present disclosure provide a chip or chip system, which includes processing circuitry configured to perform the communication method according to any one of the first aspect, the second aspect, the third aspect, the fourth aspect, and the embodiments of the first aspect, the second aspect, the third aspect, and the fourth aspect.

[0114] It can be understood that the network device, the terminal, the communication system, the storage medium, the program product, the computer program, and the chip or chip system are all used to perform the method proposed in the embodiments of the present disclosure. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method, which will not be described here.

[0115] The embodiments of the present disclosure propose a communication method, a terminal, a network device, a communication system, and a storage medium. In some embodiments, the terms of the communication method, the information processing method, the key selection method, the communication connection recovery method, and the key determination method can be replaced with each other, and the terms of the information processing system, the communication system, and the key determination system can be replaced with each other.

[0116] The embodiments of the present disclosure are not exhaustive, but are only a part of the embodiments, and are not specific limitations on the protection scope of the present disclosure. In the case of no contradiction, each step in an embodiment can be implemented as an independent embodiment, and the steps can be combined arbitrarily, for example, the scheme after removing some steps in an embodiment can also be implemented as an independent embodiment, and the order of the steps in an embodiment can be exchanged arbitrarily, in addition, the optional implementation manners in an embodiment can be combined arbitrarily; in addition, the embodiments can be combined arbitrarily, for example, some or all steps of different embodiments can be combined arbitrarily, and an embodiment can be combined with the optional implementation manners of other embodiments.

[0117] In each embodiment of the present disclosure, the terms and / or descriptions between the embodiments are consistent if there is no special description and logical conflict, and can be referred to each other, and the technical features in different embodiments can be combined to form a new embodiment according to their inherent logical relationship.

[0118] The terms used in the embodiments of the present disclosure are only for the purpose of describing specific embodiments, and not as a limitation on the present disclosure.

[0119] In the embodiments of the present disclosure, an element expressed in singular form, such as "a", "an", "the", "said", "the aforementioned", "the foregoing", "this", and the like, unless otherwise specified, can represent "one and only one", or can represent "one or more", "at least one", and the like. For example, in the case of using an article such as "a", "an", "the" in English, the noun after the article can be understood as a singular expression, or can be understood as a plural expression.

[0120] In the embodiments of the present disclosure, "plurality" refers to two or more.

[0121] In some embodiments, the terms "at least one of", "one or more", "a plurality of", "multiple", and the like can be replaced with each other.

[0122] In some embodiments, the description manner such as "at least one of A, B", "A and / or B", "A in one case, B in another case", "in response to a case A, in response to another case B", and the like, according to the case, can include the following technical solutions: in some embodiments, A is executed regardless of B; in some embodiments, B is executed regardless of A; in some embodiments, A and B are selectively executed from A and B; in some embodiments, A and B are executed (A and B are both executed). When there are more branches such as A, B, C, and the like, it is similar to the above.

[0123] In some embodiments, the description manner such as "A or B", and the like, according to the case, can include the following technical solutions: in some embodiments, A is executed regardless of B; in some embodiments, B is executed regardless of A; in some embodiments, A and B are selectively executed from A and B. When there are more branches such as A, B, C, and the like, it is similar to the above.

[0124] The prefix words of "first", "second" and the like in the embodiments of the present disclosure are merely used to distinguish different description objects, and do not constitute limitation on the position, order, priority, quantity or content of the description objects. The description objects are described in the claims or embodiments, and should not be construed as redundant limitation because of the use of the prefix words. For example, the description object is "field", and the ordinal words before "field" in "first field" and "second field" do not limit the position or order between "fields", and "first" and "second" do not limit whether the "fields" modified thereby are in the same message or not, nor limit the order of "first field" and "second field". For another example, the description object is "level", and the ordinal words before "level" in "first level" and "second level" do not limit the priority between "levels". For another example, the quantity of the description object is not limited by the ordinal words, and can be one or more. For example, "first device", wherein the quantity of "device" can be one or more. In addition, the objects modified by different prefix words can be the same or different, for example, the description object is "device", and "first device" and "second device" can be the same device or different devices, and the types thereof can be the same or different. For another example, the description object is "information", and "first information" and "second information" can be the same information or different information, and the contents thereof can be the same or different.

[0125] In some embodiments, "including A", "containing A", "for indicating A", "carrying A" can be interpreted as directly carrying A, or indirectly indicating A.

[0126] In some embodiments, the terms of "in response to", "in response to determining", "in the case of", "when", "when", "if", "if" and the like can be replaced with each other.

[0127] In some embodiments, the terms of "greater than", "greater than or equal to", "not less than", "more than", "more than or equal to", "not less than", "higher than", "higher than or equal to", "not lower than", "above" and the like can be replaced with each other, and the terms of "less than", "less than or equal to", "not greater than", "less than", "less than or equal to", "not more than", "lower than", "lower than or equal to", "not higher than", "below" and the like can be replaced with each other.

[0128] In some embodiments, an apparatus and the like can be interpreted as an entity, and can also be interpreted as virtual, and the name thereof is not limited to the name described in the embodiments. The terms "apparatus", "equipment", "device", "circuit", "network element", "node", "function", "unit", "section", "system", "network", "chip", "chip system", "entity", "subject" and the like can be replaced with each other.

[0129] In some embodiments, a "network" can be interpreted as an apparatus (for example, an access network device, a core network device, and the like) included in the network.

[0130] In some embodiments, the terms "network device", "access network device (AN device)", "radio access network device (RAN device)", "base station (BS)", "radio base station", "fixed station", "node", "access network node", "access point", "transmission point (TP)", "reception point (RP)", "transmission / reception point (TRP)", "panel", "antenna panel", "antenna array", "cell", "macro cell", "small cell", "femtocell", "pico cell", "sector", "cell group", "serving cell", "carrier", "component carrier", "bandwidth part (BWP)" and the like can be replaced with each other.

[0131] In some embodiments, the terms "terminal," "terminal device," "user equipment (UE)," "user terminal," "mobile station (MS)," "mobile terminal (MT)," "subscriber station," "mobile unit," "subscriber unit," "wireless unit," "remote unit," "mobile device," "wireless device," "wireless communication device," "remote device," "mobile subscriber station," "access terminal," "mobile terminal," "wireless terminal," "remote terminal," "handset," "user agent," "mobile client," "client," and so on can be replaced with each other.

[0132] In some embodiments, the access network device, the core network device, or the network device can be replaced with a terminal. For example, the embodiments of the present disclosure can also be applied to a structure in which communication between the access network device, the core network device, or the network device and the terminal is replaced with communication between a plurality of terminals (e.g., device-to-device (D2D), vehicle-to-everything (V2X), etc.). In this case, the terminal can also be configured to have all or part of the functions of the access network device. In addition, the terms "uplink," "downlink," and the like can also be replaced with terms corresponding to the inter-terminal communication (e.g., "side"). For example, the uplink channel, the downlink channel, and the like can be replaced with the side channel, and the uplink, the downlink, and the like can be replaced with the sidelink.

[0133] In some embodiments, the terminal can be replaced with the access network device, the core network device, or the network device. In this case, the access network device, the core network device, or the network device can also be configured to have all or part of the functions of the terminal.

[0134] In some embodiments, the data, information, etc. can be obtained in compliance with the laws and regulations of the country in which the location is situated.

[0135] In some embodiments, the data, information, etc. can be obtained after obtaining the consent of the user.

[0136] In addition, each element, each row, or each column in the table of the embodiments of the present disclosure can be implemented as an independent embodiment, and any combination of any element, any row, or any column can also be implemented as an independent embodiment.

[0137] FIG. 1 is a schematic diagram of an architecture of a communication system according to an embodiment of the present disclosure. As shown in FIG. 1, the communication system 100 includes a terminal 101 and a network device 102.

[0138] In some embodiments, the terminal 101 includes at least one of a mobile phone, a wearable device, an Internet of Things device, a car with communication function, a smart car, a Pad, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical surgery, a wireless terminal device in smart grid, a wireless terminal device in transportation safety, a wireless terminal device in smart city, a wireless terminal device in smart home, etc., but is not limited thereto.

[0139] In some embodiments, the network device 102 can include an access network device and / or a core network device. The access network device is, for example, a node or device that accesses a terminal to a wireless network, and can include at least one of an evolved NodeB (eNB), a next generation eNB (ng-eNB), a next generation NodeB (gNB), a node B (NB), a home node B (HNB), a home evolved node B (HeNB), a wireless backhaul device, a radio network controller (RNC), a base station controller (BSC), a base transceiver station (BTS), a base band unit (BBU), a mobile switching center, a base station in a 6G communication system, an Open RAN, a Cloud RAN, a base station in other communication systems, an access node in a Wi-Fi system, but is not limited thereto.

[0140] In some embodiments, the technical solutions of the present disclosure can be applicable to an Open RAN architecture, at which time the interfaces between or within the network devices involved in the embodiments of the present disclosure can become internal interfaces of the Open RAN, and the processes and information interactions between these internal interfaces can be realized by software or programs.

[0141] In some embodiments, the access network device can be composed of a central unit (CU) and a distributed unit (DU), where the CU can also be referred to as a control unit. The CU-DU structure can split the protocol layers of the network device 102, with part of the protocol layers being controlled by the CU, and the remaining part or all of the protocol layers being distributed in the DU and controlled by the CU, but is not limited thereto.

[0142] In some embodiments, the core network device can be one device including a first network element, or a plurality of devices or device groups each including a first network element. The network element can be virtual or physical. The core network can include at least one of an evolved packet core (EPC), a 5G core network (5GCN), and a next generation core (NGC).

[0143] It can be understood that the communication system described in the embodiments of the present disclosure is for more clearly illustrating the technical solutions of the embodiments of the present disclosure, and does not constitute a limitation on the technical solutions provided by the embodiments of the present disclosure. Those skilled in the art can know that, with the evolution of system architecture and the appearance of new business scenarios, the technical solutions provided by the embodiments of the present disclosure are also applicable to similar technical problems.

[0144] [According to Rule 91, correct on August 21, 2024] The embodiments of the present disclosure described below can be applied to the communication system 100 shown in FIG. 1, or part of the subject, but are not limited thereto. The subjects shown in FIG. 1 are illustrative, and the communication system can include all or part of the subjects in FIG. 1, or other subjects other than FIG. 1, the number and form of each subject is arbitrary, the connection relationship between each subject is illustrative, each subject can not be connected or can be connected, the connection can be any way, can be direct connection or indirect connection, can be wired connection or wireless connection.

[0145] Embodiments of the present disclosure can be applied to Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 5G new radio (NR), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (Bluetooth (registered trademark)), Public Land Mobile Network (PLMN) network, Device-to-Device (D2D) system, Machine to Machine (M2M) system, Internet of Things (IoT) system, Vehicle-to-Everything (V2X), system using other communication methods, next-generation system expanded based thereon, and the like. In addition, a plurality of systems can be combined (for example, combination of LTE or LTE-A and 5G, and the like).

[0146] Hereinafter, terms related to the present disclosure are explained and interpreted.

[0147] I. LTM:

[0148] In a communication system, a network side can provide a terminal with multiple candidate cell (or cell group) configurations. In some embodiments, the network side can later control the terminal to change among multiple candidate cells (or cell groups) associated with the multiple candidate cell (or cell group) configurations through L1 signaling (e.g., downlink control information (DCI)) or L2 signaling (e.g., media access control (MAC) control element (CE)).

[0149] In an example, the serving cell (or cell group) configuration is changed from “candidate cell (or cell group) configuration-1” to “candidate cell (or cell group) configuration-2”.

[0150] In some embodiments, 1 serving cell (or serving cell group) can correspond to 1 or more “candidate cell (or candidate cell group)”.

[0151] In some embodiments, if the LTM type of cell change is triggered, the network node (e.g., gNB or gNB-CU) to which the target cell belongs and the network node to which the source cell belongs do not change, the terminal’s key does not need to be updated. If the LTM type of cell change is triggered, the network node (e.g., gNB or gNB-CU) to which the target cell belongs and the network node to which the source cell belong change, the terminal’s key needs to be updated.

[0152] In some embodiments, a cell group can be a master cell group (MCG) and a secondary cell group (SCG).

[0153] In some embodiments, the MCG includes at least one primary cell (PCell). In addition, it can include one or more secondary cells (SCell).

[0154] In some embodiments, the SCG includes at least one primary secondary cell (PSCell). In addition, it can include one or more secondary cells (SCell). Because many signals are only sent on the PCell and the PSCell, for the convenience of description, a concept of special cell (sPCell) is also defined in the relevant communication protocol, and the PCell and the PSCell are collectively referred to as the sPCell.

[0155] In some embodiments, the terminal can use one or more keys configured by the network device for the candidate cell (cell group) configuration (or preconfigured cell (cell group) configuration). In some embodiments, in the case where the network device configures multiple keys, the terminal can select one key from the multiple keys for the candidate cell (cell group) configuration (or preconfigured cell (cell group) configuration).

[0156] It should be noted that the terms "change", "change", "switch", "move" and the like can be replaced with each other.

[0157] II. Conditionally triggered layer 3 (L3) mobility:

[0158] The conditionally triggered L3 mobility includes: conditional handover (CHO), conditional PSCell addition (CPA), conditional PSCell change (CPC).

[0159] CHO refers to: the handover performed by the UE when one or more handover execution conditions are met. The UE starts to evaluate the execution conditions after receiving the CHO configuration, and stops evaluating the execution conditions after performing the handover (including legacy handover and CHO).

[0160] CPA refers to: the PSCell addition performed by the UE when the execution condition is met. The UE starts to evaluate the execution condition when receiving the configuration of CPA, and stops evaluating the execution condition once the PCell addition or PCell change is triggered.

[0161] CPC refers to: the PSCell change performed by the UE when the execution condition is met. The terminal starts to evaluate the execution condition after receiving the CPC configuration, and stops evaluating the execution condition once the PCell changes or the PCell change is triggered.

[0162] In some embodiments, CPA and CPC can be collectively referred to as conditional PSCell addition or change (CPAC).

[0163] In some embodiments, the terminal can change the specific cell (or cell group) configuration according to the indication of the network device after the trigger condition is met. In an example, the PCell configuration of the terminal is changed from "candidate cell (or cell group) configuration-1" to "candidate cell (or cell group) configuration-2".

[0164] In some embodiments, the network device can also configure a corresponding trigger condition for the candidate configuration of LTM. When the terminal satisfies the trigger condition (e.g., a specific measurement event), the terminal changes the serving cell configuration (or cell group configuration) to the "candidate configuration of LTM". This "mobility procedure based on condition triggering" type can be referred to as conditional LTM procedure (C-LTM)

[0165] In some embodiments, the terminal can use one or more keys configured by the network device for the candidate cell (cell group) configuration (or preconfigured cell (cell group) configuration). In some embodiments, in the case where the network device configures multiple keys, the terminal can select one key from the multiple keys for the candidate cell (cell group) configuration (or preconfigured cell (cell group) configuration).

[0166] III. Radio Resource Control (RRC) Connection:

[0167] The RRC connection is a connection mode in a wireless communication network. The RRC is responsible for the broadcast of network system information to user equipment, and the establishment, re-establishment, maintenance and release of the connection between the UE and the radio access network.

[0168] In some embodiments, the communication connection failure of the terminal can include at least one of the following: radio link failure, cell handover failure, cell change failure, cell group change failure.

[0169] In some embodiments, the radio link failure can include at least one of the following: random access procedure failure, radio link control (RLC) entity data transmission failure, physical layer out-of-sync failure.

[0170] In an example, the random access procedure failure can be a failure caused by the number of random access reaching a maximum number. In an example, the RCL entity data transmission failure can be a failure caused by the number of RLC layer data transmission reaching a maximum number. In an example, the physical layer out-of-sync failure can be a failure caused by the out-of-sync timer expiring.

[0171] In some embodiments, the cell handover failure can include at least one of the following: normal handover failure, conditional handover procedure failure, handover failure based on dynamic cell (cell group) change.

[0172] In an example, the ordinary handover failure can be that the terminal starts a timer after receiving an ordinary handover command, and before the timer expires, the access to the target cell indicated by the ordinary handover command is not successfully completed. In an example, the conditional handover procedure failure can be a failure of the L3 mobility procedure triggered based on a condition. In an example, the handover failure based on dynamic cell (cell group) change can be an LTM handover failure.

[0173] In an example, the cell change failure can be an SCell change failure.

[0174] In an example, the cell group change failure can be an MCG change failure or an SCG cell group change failure.

[0175] In some embodiments, since the terminal can trigger cell handover based on its own judgment condition, and in the case of handover failure, the network device cannot know the candidate cell (cell group) configuration used by the terminal in the handover procedure, therefore, in the process of connection recovery performed by the terminal, the key used by the terminal and the key determined by the network device are inconsistent, that is, the terminal and the network device cannot reach a consistent understanding about the key used in the connection recovery process.

[0176] In an example, the terminal selects “candidate cell (cell group) configuration-1” and “key = 1” for cell handover. In the connection recovery process after the handover failure, the terminal selects “candidate cell (cell group configuration)-1” again, at this time, the terminal determines that “candidate cell (cell group) configuration-1” is used twice, and the corresponding key is “key = 2”. Since the handover fails, the network device cannot know that the terminal has used “candidate cell (cell group) configuration-1”, therefore, the network device determines that “candidate cell (cell group configuration)-1” is used once, and then the network device determines that the key corresponding to “candidate cell (cell group) configuration-1” used in the communication connection recovery is “key = 1”, so that the terminal and the network device do not understand the key used in the communication connection recovery process consistently, which further causes the communication connection recovery to fail.

[0177] Embodiments of the present disclosure provide a communication method, a terminal, a network device, a communication system and a storage medium, the terminal and the network device determine a first key corresponding to a first candidate configuration used in a communication connection recovery process based on a first rule, so that the understanding of the terminal and the network device about the first key remains consistent, thereby increasing the probability of communication connection recovery and improving the security of communication connection.

[0178] In some embodiments, the first rule can be specified by a protocol or configured by the network device.

[0179] In some embodiments, the first rule includes one of the following:

[0180] Rule 1: Determine a first key (denoted as key a) from a set of keys (denoted as key set A) configured by the network device.

[0181] Rule 2: Determine the key a based on a used key and a first value. In an embodiment, the first value can be pre-configured, e.g., as specified by a protocol.

[0182] Rule 3: Determine the key a based on a used key in the key set A and a second value. In an embodiment, the second value can be pre-configured, e.g., as specified by a protocol.

[0183] In some embodiments, the first value and the second value can be the same or different.

[0184] In some embodiments, the key set A includes at least one of a first key set (denoted as key set B), a second key set (denoted as key set C), a third key set (denoted as key set D), and a fourth key set (denoted as key set E).

[0185] In some embodiments, each of the above key sets can include one or more keys. A key can be indicated by a key label, in which case a key set can include one or more key labels.

[0186] In some embodiments, a key can be a next hop chaining counter (NCC) value.

[0187] In some embodiments, some of the above key sets can be the same.

[0188] In an example, the key set B and the key set C can be the same, i.e., the keys in the key set B and the keys in the key set C are exactly the same.

[0189] In some embodiments, at least some of the above key sets can be different.

[0190] In an example, the key set B and the key set C can be different. In other words, the keys in the key set B and the keys in the key set C are partially different, or the keys in the key set B and the keys in the key set C are exactly different.

[0191] In some embodiments, the key set B is associated with a first candidate configuration (denoted as candidate configuration a), and the candidate configuration a is used for communication connection recovery.

[0192] In some embodiments, the key set B can also be associated with a configuration set to which the candidate configuration a belongs. In this case, the terminal can also select keys corresponding to other candidate configurations in the configuration set to which the candidate configuration a belongs from the key set B when using the other candidate configurations.

[0193] In some embodiments, the key set B can be used for communication connection recovery.

[0194] In some embodiments, the key set B can also be used for cell switching, in which case the key set B can also be associated with a second candidate configuration (denoted as candidate configuration b), which is used for cell switching.

[0195] In some embodiments, the key set C is associated with the candidate configuration b, and the key set C can be used for cell switching.

[0196] In some embodiments, the key set C can also be associated with a configuration set to which the candidate configuration b belongs. In this case, the terminal can also select keys corresponding to other candidate configurations in the configuration set to which the candidate configuration b belongs from the key set C when using the other candidate configurations.

[0197] In some embodiments, the key set C can also be used for communication connection recovery, in which case the key set B can also be associated with the candidate configuration a.

[0198] In some embodiments, the candidate configuration a and the candidate configuration b can be the same or different.

[0199] In some embodiments, the candidate configuration a and the candidate configuration b can belong to different configuration sets.

[0200] In some embodiments, the candidate configuration a and the candidate configuration b can also belong to the same configuration set.

[0201] In some embodiments, a first cell (denoted as cell a) corresponding to the candidate configuration a and a second cell (denoted as cell b) corresponding to the candidate configuration b belong to the same cell set.

[0202] In some embodiments, the cell a and the cell b are the same.

[0203] In some embodiments, the key set D is associated with a candidate configuration set (denoted as configuration set A) configured by the network, the configuration set A is used by the terminal to determine the candidate configuration a, and the key set D is dedicated to a communication connection recovery process.

[0204] In some embodiments, the configuration set A can also be used by the terminal to determine the candidate configuration b.

[0205] In some embodiments, the configuration set A can include one or more candidate configurations.

[0206] In some embodiments, in the case that the configuration set A includes one candidate configuration, the candidate configuration can be used for different communication procedures, for example, the candidate configuration is used for both the communication connection recovery procedure and the cell handover procedure, at this time, the candidate configurations used by different communication procedures are the same, for example, the candidate configuration a and the candidate configuration b are the same.

[0207] In some embodiments, in the case that the configuration set A includes multiple candidate configurations, the multiple candidate configurations can be used for the same communication procedure, or can be used for different communication procedures respectively, for example, a part of the multiple candidate configurations is used for the communication connection recovery procedure, and another part of the multiple candidate configurations is used for the cell handover procedure, at this time, the candidate configurations used by different communication procedures are different, for example, the candidate configuration a and the candidate configuration b are different.

[0208] In some embodiments, the configuration set A includes at least one of the following: a first candidate configuration set (denoted as configuration set B), a second candidate configuration set (denoted as configuration set C).

[0209] In some embodiments, the candidate configuration a belongs to the configuration set B, and the configuration set B is used for the communication connection recovery.

[0210] In some embodiments, the candidate configuration b belongs to the configuration set C, and the configuration set C is used for the cell handover.

[0211] In some embodiments, the configuration set B and the configuration set C can be the same. In other words, the candidate configurations in the configuration set B and the candidate configurations in the configuration set C are completely the same.

[0212] In some embodiments, the configuration set B and the configuration set C can be different. In other words, the candidate configurations in the configuration set B and the candidate configurations in the configuration set C are partially the same, or the candidate configurations in the configuration set B and the candidate configurations in the configuration set C are completely different.

[0213] In some embodiments, the key set E is associated with the serving cell c used by the terminal before the communication connection recovery, and the key set E is dedicated to the target candidate configuration in the communication connection recovery procedure.

[0214] In some embodiments, the target candidate configuration at least includes the candidate configuration a.

[0215] In some embodiments, the serving cell c corresponds to the candidate configuration c, at this time, the key set E is also associated with the candidate configuration c. In this case, the target candidate configuration can also include the candidate configuration c.

[0216] In some embodiments, the key set E can also be associated with the configuration set to which the candidate configuration c belongs.

[0217] In some embodiments, the candidate configuration c and the candidate configuration a can belong to the same configuration set.

[0218] FIG. 2A is a first interaction diagram of a communication method according to embodiments of the present disclosure. As shown in FIG. 2A, embodiments of the present disclosure relate to a communication method. The communication method is performed by the communication system 100, and includes steps S2101-S2106.

[0219] In embodiments of the present disclosure, the terminal and the network device determine the key a based on rule 1.

[0220] In step S2101, the network device sends a configuration set A.

[0221] In some embodiments, the terminal receives the configuration set A, which is used by the terminal to determine the candidate configuration a.

[0222] In some embodiments, step S2101 can be omitted, in which case the terminal can determine the candidate configuration a from the used candidate configurations.

[0223] In step S2102, the network device sends a key set A.

[0224] In some embodiments, the terminal receives the key set A.

[0225] In some embodiments, the configuration set A and the key set A can be carried in the same information and delivered to the terminal together. Alternatively, the key set A can be included in the configuration set A and delivered to the terminal together.

[0226] In some embodiments, step S2101 and step S2102 can be performed simultaneously.

[0227] In some embodiments, step S2102 and step S2102 can be performed in reverse order.

[0228] In step S2103, the terminal determines the candidate configuration a from the configuration set A after the communication connection fails.

[0229] In some embodiments, the communication connection failure of the terminal can include at least one of the following: radio link failure, cell handover failure, cell change failure, cell group change failure.

[0230] In some embodiments, the terminal can determine the candidate configuration a from the unused candidate configurations in the configuration set A.

[0231] In some embodiments, the terminal can determine the candidate configuration a from the used candidate configurations in the configuration set A.

[0232] In some embodiments, the terminal can determine the candidate configuration a from the candidate configurations that have been used by the terminal and for which the communication connection is successful in the configuration set A.

[0233] In some embodiments, the terminal can determine the candidate configuration a from the candidate configurations that have not been used by the terminal before the cell switching in the configuration set A. In other words, the candidate configurations used in the cell switching procedure in the configuration set A are also considered as not used. Alternatively, the candidate configurations used in the cell switching procedure can also be the candidate configuration a. In some embodiments, if the terminal has performed a plurality of cell switching procedures before the communication connection failure, the cell switching procedure referred to herein can be understood as the last cell switching procedure before the communication connection failure.

[0234] In some embodiments, the configuration set A comprises a configuration set B, the configuration set B is used for the communication connection recovery, and the terminal can determine the candidate configuration a from the configuration set B.

[0235] In some embodiments, the configuration set A comprises a configuration set C, the configuration set C is used for the cell switching, and the terminal can determine the candidate configuration a from the configuration set C.

[0236] In some embodiments, the terminal can determine the candidate configuration b as the candidate configuration a.

[0237] In some embodiments, the terminal can determine the candidate configuration c corresponding to the serving cell c used before the communication connection recovery as the candidate configuration a.

[0238] In some embodiments, the terminal can determine the candidate configuration a used for the communication connection recovery from the configuration set A according to the arrangement order of the candidate configurations.

[0239] In some embodiments, the terminal can determine the candidate configuration a used for the communication connection recovery from the configuration set A according to the value of the indication information of the candidate configurations. The indication information is used to indicate the candidate configuration.

[0240] In some embodiments, the indication information is configured by the network device. In an example, the indication information is the identification (ID) of the candidate configuration.

[0241] In some embodiments, when the terminal does not receive the configuration set A, the terminal can determine the candidate configuration a as the candidate configuration used last time.

[0242] In some embodiments, when the terminal does not receive the configuration set A, the terminal can determine the candidate configuration a as the candidate configuration used last time before the cell switching.

[0243] In some embodiments, in the case that the terminal does not receive the configuration set A, the terminal can determine the candidate configuration a as the candidate configuration used in the last successful communication connection.

[0244] In some embodiments, the methods of determining the candidate configuration a described in the various embodiments above can be used in combination with each other without conflict, which will not be described herein.

[0245] In some embodiments, the methods of determining the candidate configuration a described in the various embodiments above are specified by the protocol or configured by the network device. In other words, the network device can be aware of the candidate configuration a determined by the terminal, so that the terminal and the network device can reach a common understanding on the candidate configuration a used for the communication connection recovery.

[0246] In some embodiments, the terminal can also send the second information to the network device, the second information indicating the candidate configuration a, so as to inform the network device of the candidate configuration a.

[0247] In step S2104, the terminal determines the key a associated with the candidate configuration a from the key set A.

[0248] In some embodiments, the key set A includes the key set B associated with the candidate configuration a.

[0249] In some embodiments, the terminal can determine the key a from the keys in the key set B that have not been used.

[0250] In some embodiments, the terminal can determine the key a from the keys in the key set B that have been used.

[0251] In some embodiments, the terminal can determine the key a from the keys in the key set B that have been used and in the successful communication connection.

[0252] In some embodiments, the terminal can determine the key a from the keys in the key set B that have not been used before the cell switching of the terminal. In other words, the keys used in the cell switching process in the key set B are also considered as not used. Alternatively, the keys used in the cell switching process in the key set B can also be the key a.

[0253] In some embodiments, the key set A includes the key set C associated with the candidate configuration b.

[0254] In some embodiments, the terminal can determine the key a from the key set C.

[0255] In some embodiments, the terminal can determine the key a from the keys in the key set C that have not been used.

[0256] In some embodiments, the terminal can determine the key a from the keys that have been used and for which the communication connection has succeeded in the key set C.

[0257] In some embodiments, the terminal can determine the key a from the keys that have been used and for which the communication connection has succeeded in the key set C.

[0258] In some embodiments, the terminal can determine the key a from the keys that have been used and for which the communication connection has succeeded in the key set C.

[0259] In some embodiments, the key set A includes a key set D associated with the configuration set A.

[0260] In some embodiments, the terminal can determine the key a from the key set D.

[0261] In some embodiments, the method of determining the key a from the key set D can refer to the method of determining the key a from the key set B or the key set C, which will not be repeated here.

[0262] In some embodiments, the key set A includes a key set E associated with the serving cell c.

[0263] In some embodiments, the terminal can determine the key a from the key set E.

[0264] In some embodiments, the method of determining the key a from the key set E can refer to the method of determining the key a from the key set B or the key set C, which will not be repeated here.

[0265] In some embodiments, the terminal can determine the key a used for the communication connection recovery from the key set A according to the arrangement order of each key.

[0266] In some embodiments, the terminal can determine the key a used for the communication connection recovery from the key set A according to the numerical value of each key.

[0267] In some embodiments, the methods of determining the key a described in the above various embodiments can be used in combination with each other, which will not be repeated here.

[0268] In some embodiments, the methods of determining the key a described in the above various embodiments all belong to specific embodiments of rule 1.

[0269] In step S2105, the terminal performs communication connection recovery based on the key a and the candidate configuration a.

[0270] In some embodiments, the terminal sends an RRC reestablishment request (RRC connection resume) message, an RRC connection resume message, an RRC setup request message, etc. to the network device based on the key a and the candidate configuration a. Among them, the key a is carried in the above messages. After the network device allows the terminal to access, the network device sends an RRC reestablishment message to the terminal, the terminal determines the candidate cell corresponding to the candidate configuration a based on the candidate configuration a, and accesses the candidate cell. In the access process, the terminal uses the key a for security verification. After successful access, the terminal sends an RRC reestablishment complete message to the network device.

[0271] In step S2106, the terminal sends first information.

[0272] In some embodiments, the network device receives the first information.

[0273] In some embodiments, the first information is used to indicate the key a. In some embodiments, the first information can be a key label of the key a.

[0274] In some embodiments, the first information is carried in a first message, and the first message is used to request communication connection recovery. In an example, the first message can be a connection reestablishment request message, a connection configuration complete message, a medium access control layer message, etc.

[0275] In some embodiments, after receiving the first information, the network device can determine the key a used by the terminal for encryption and / or integrity protection according to the key a indicated by the first information and the rule 1.

[0276] In some embodiments, step S2106 can be omitted, in which case the network device can determine the key a used by the terminal based on the rule 1, and the key a determined by the network device can be used for encryption and / or integrity protection between the terminal and the network device.

[0277] In some embodiments, step S2105 and step S2106 can be executed simultaneously.

[0278] In some embodiments, step S2105 and step S2106 can be executed in reverse order.

[0279] The communication method related to the embodiments of the present disclosure can include at least one of steps S2101 to S2106. For example, step S2101 can be implemented as an independent embodiment. For example, step S2102 can be implemented as an independent embodiment. For example, step S2103 can be implemented as an independent embodiment. For example, step S2104 can be implemented as an independent embodiment. For example, step S2105 can be implemented as an independent embodiment. For example, step S2106 can be implemented as an independent embodiment. For example, step S2101 and step S2102 can be combined to be implemented as an independent embodiment. For example, step S2103 and step S2104 can be combined to be implemented as an independent embodiment. For example, step S2104 and step S2105 can be combined to be implemented as an independent embodiment. For example, step S2104 and step S2106 can be combined to be implemented as an independent embodiment. For example, step S2104, step S2105, and step S2106 can be combined to be implemented as an independent embodiment. But the present disclosure is not limited to this.

[0280] FIG. 2B is a second kind of interaction schematic diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG. 2B, the embodiment of the present disclosure relates to a communication method. The communication method is performed by the communication system 100 and includes steps S2201 to S2205.

[0281] In the embodiment of the present disclosure, the terminal and the network device determine the first key based on rule 2.

[0282] In step S2201, the network device sends the configuration set A.

[0283] Other optional implementation manners of step S2201 can refer to the optional implementation manners of step S2101 of FIG. 2A and other associated parts in the embodiments related to FIG. 2A, which will not be described here.

[0284] In step S2202, the terminal determines the candidate configuration a from the configuration set A after the communication connection fails.

[0285] Other optional implementation manners of step S2202 can refer to the optional implementation manners of step S2103 of FIG. 2A and other associated parts in the embodiments related to FIG. 2A, which will not be described here.

[0286] In step S2203, the terminal determines the key a based on the used key and the second value.

[0287] In some embodiments, the terminal can determine the key a based on the last used key and the second value.

[0288] In an example, the key used by the terminal last time is NCC(old) = 1, and the second value is 2, then the key a is NCC(new) = NCC(old) + 2 = 3.

[0289] In some embodiments, the terminal can determine the key a based on the key used last time before the cell switch and the second value.

[0290] In an example, the key used before the switch is NCC(pre-handover) = 1, the second value is 1, and the key used in the switch process is NCC(handover) = NCC(pre-handover) + 1 = 2, then the key a is NCC(new) = NCC(pre-handover) + 1 = 2.

[0291] In some embodiments, the terminal can determine the key a based on the key used last time before the cell switch and the second value.

[0292] In some embodiments, the method for determining the key a described in each of the above embodiments belongs to a specific embodiment of rule 2.

[0293] In step S2204, the terminal performs communication connection recovery based on the key a and the candidate configuration a.

[0294] Other optional implementations of step S2204 can be referred to optional implementations of step S2105 of FIG. 2A, and other associated parts in the embodiments involved in FIG. 2A, which will not be repeated here.

[0295] In step S2205, the terminal sends the first information.

[0296] Optional implementations of step S2205 can be referred to optional implementations of step S2106 of FIG. 2A, and other associated parts in the embodiments involved in FIG. 2A, which will not be repeated here. In some embodiments, step S2205 can be omitted, in which case the network device can determine the key a used by the terminal based on rule 2.

[0297] Other optional implementations of step S2205 can be referred to optional implementations of step S2106 of FIG. 2A, and other associated parts in the embodiments involved in FIG. 2A, which will not be repeated here.

[0298] The communication method related to the embodiments of the present disclosure can include at least one of steps S2201 to S2205. For example, step S2201 can be implemented as an independent embodiment. For example, step S2202 can be implemented as an independent embodiment. For example, step S2203 can be implemented as an independent embodiment. For example, step S2204 can be implemented as an independent embodiment. For example, step S2205 can be implemented as an independent embodiment. For example, step S2202 and step S2203 can be combined and implemented as an independent embodiment. For example, step S2203 and step S2204 can be combined and implemented as an independent embodiment. For example, step S2203 and step S2205 can be combined and implemented as an independent embodiment. For example, step S2203, step S2204, and step S2205 can be combined and implemented as an independent embodiment. But the present disclosure is not limited to this.

[0299] FIG. 2C is a third interaction schematic diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG. 2C, the present disclosure relates to a communication method. The communication method is performed by the communication system 100 and includes steps S2301 to S2306.

[0300] In the embodiments of the present disclosure, the terminal and the network device determine the key a based on rule 3.

[0301] In step S2301, the network device sends the configuration set A.

[0302] Other optional implementation manners of step S2301 can refer to the optional implementation manners of step S2101 of FIG. 2A and other associated parts in the embodiments related to FIG. 2A, which will not be described here.

[0303] In step S2302, the network device sends the key set A.

[0304] Other optional implementation manners of step S2302 can refer to the optional implementation manners of step S2102 of FIG. 2A and other associated parts in the embodiments related to FIG. 2A, which will not be described here.

[0305] In step S2303, the terminal determines the candidate configuration a from the candidate configuration set A after the communication connection fails.

[0306] Other optional implementation manners of step S2303 can refer to the optional implementation manners of step S2103 of FIG. 2A and other associated parts in the embodiments related to FIG. 2A, which will not be described here.

[0307] In step S2304, the terminal determines the key a based on the used key in the key set A and the first value or the second value.

[0308] Other optional implementation of step S2304 can refer to optional implementation of step S2104 in FIG. 2A, optional implementation of step S2203 in FIG. 2B, other associated parts in embodiments related to FIG. 2A, and other associated parts in embodiments related to FIG. 2B, which are not described herein again.

[0309] In step S2305, the terminal performs communication connection recovery based on the key a and the candidate configuration a.

[0310] Other optional implementation of step S2305 can refer to optional implementation of step S2105 in FIG. 2A, and other associated parts in embodiments related to FIG. 2A, which are not described herein again.

[0311] In step S2306, the terminal sends the first information.

[0312] In some embodiments, step S2306 can be omitted, in which case the network device can determine the key a adopted by the terminal based on rule 3.

[0313] Other optional implementation of step S2306 can refer to optional implementation of step S2106 in FIG. 2A, and other associated parts in embodiments related to FIG. 2A, which are not described herein again.

[0314] The communication method related to the embodiments of the present disclosure can include at least one of steps S2301 to S2306. For example, step S2301 can be implemented as an independent embodiment. For example, step S2302 can be implemented as an independent embodiment. For example, step S2303 can be implemented as an independent embodiment. For example, step S2304 can be implemented as an independent embodiment. For example, step S2305 can be implemented as an independent embodiment. For example, step S2306 can be implemented as an independent embodiment. For example, step S2301 and step S2302 can be combined to be implemented as an independent embodiment. For example, step S2303 and step S2304 can be combined to be implemented as an independent embodiment. For example, step S2304 and step S2305 can be combined to be implemented as an independent embodiment. For example, step S2304 and step S2306 can be combined to be implemented as an independent embodiment. For example, step S2304, step S2305, and step S2306 can be combined to be implemented as an independent embodiment. But not limited to this.

[0315] In some embodiments, the terms of “candidate cell configuration”, “candidate cell group configuration”, “candidate configuration”, “cell configuration”, and the like can be replaced with each other.

[0316] In some embodiments, the names of information and the like are not limited to the names described in the embodiments, and terms such as "information", "message", "signal", "signaling", "report", "configuration", "indication", "instruction", "command", "channel", "parameter", "domain", "field", "symbol", "symbol", "codebook", "codeword", "codepoint", "bit", "data", "program", "chip", and the like can be replaced with each other.

[0317] In some embodiments, terms such as "carrying", "including", "containing", "packaging", and the like can be replaced with each other.

[0318] In some embodiments, terms such as "radio", "wireless", "radio access network (RAN)", "access network (AN)", "RAN-based", and the like can be replaced with each other.

[0319] In some embodiments, "acquiring", "obtaining", "getting", "receiving", "transmitting", "bidirectional transmission", "sending and / or receiving", and the like can be replaced with each other, which can be interpreted as receiving from other subjects, acquiring from protocols, acquiring from higher layers, obtaining by processing oneself, implementing autonomously, and the like.

[0320] In some embodiments, terms such as "sending", "transmitting", "reporting", "transmitting", "requesting", "bidirectional transmission", "sending and / or receiving", and the like can be replaced with each other.

[0321] In some embodiments, terms such as "issuing", "returning", "feedback", "response", "reply", and the like can be replaced with each other.

[0322] In some embodiments, the terms "certain", "preset", "pre-set", "set", "indicated", "any", "first", and the like can be replaced with each other, "certain A", "preset A", "pre-set A", "set A", "indicated A", "any A", "first A" can be interpreted as A predetermined in a protocol or the like, can be interpreted as A obtained by setting, configuring, or indicating, or the like, can be interpreted as certain A, any A, or first A, and the like, but are not limited thereto.

[0323] In some embodiments, the determination or judgment can be made by a value represented by 1 bit (0 or 1), can be made by a true or false value (Boolean value) represented by true or false, can be made by comparison of numerical values (for example, comparison with a predetermined value), but is not limited thereto.

[0324] FIG. 3A is a flow diagram of a communication method performed by a terminal according to an embodiment of the present disclosure. As shown in FIG. 3A, the present embodiment relates to a communication method performed by a terminal. The above communication method includes steps S3101 to S3105.

[0325] In step S3101, a configuration set A is received.

[0326] The optional implementation of step S3101 can refer to the optional implementation of step S2101 of FIG. 2A, other associated parts in the embodiments related to FIG. 2A, other associated parts in the embodiments related to FIG. 2C, which will not be repeated here.

[0327] In step S3102, a key set A is received.

[0328] The optional implementation of step S3102 can refer to the optional implementation of step S2201 of FIG. 2A, other associated parts in the embodiments related to FIG. 2A, which will not be repeated here.

[0329] In step S3103, after the communication connection fails, the candidate configuration a is determined.

[0330] The optional implementation of step S3103 can refer to the optional implementation of step S2103 of FIG. 2A, other associated parts in the embodiments related to FIG. 2A, which will not be repeated here.

[0331] In step S3104, the key a associated with the candidate configuration a is determined according to a first rule.

[0332] The optional implementation of step S3104 can refer to the optional implementation of step S2104 in FIG. 2A, the optional implementation of step S2203 in FIG. 2B, the optional implementation of step S2304 in FIG. 2C, other associated parts in the embodiments related to FIG. 2A, other associated parts in the embodiments related to FIG. 2B, other associated parts in the embodiments related to FIG. 2C, not described herein again.

[0333] In step S3105, the communication connection is resumed based on the candidate configuration a and the key a.

[0334] The optional implementation of step S3105 can refer to the optional implementation of step S2105 in FIG. 2A, other associated parts in the embodiments related to FIG. 2A, not described herein again.

[0335] In some embodiments, after step S3104, the communication method can further include: sending first information. The first information is used to indicate the key a.

[0336] The optional implementation of receiving the first information described above can refer to the optional implementation of step S2106 in FIG. 2A, other associated parts in the embodiments related to FIG. 2A, not described herein again.

[0337] The communication method related to the embodiments of the present disclosure can include at least one of steps S3101 to S3105. For example, step S3101 can be implemented as an independent embodiment. For example, step S3102 can be implemented as an independent embodiment. For example, step S3103 can be implemented as an independent embodiment. For example, step S3104 can be implemented as an independent embodiment. For example, step S3105 can be implemented as an independent embodiment. For example, step S3101 and step S3102 can be combined to be implemented as an independent embodiment. For example, step S3103 and step S3104 can be combined to be implemented as an independent embodiment. For example, step S3104 and step S3105 can be combined to be implemented as an independent embodiment. For example, step S3104 and step S3105 can be combined to be implemented as an independent embodiment. For example, step S3103, step S3104 and step S3105 can be combined to be implemented as an independent embodiment. But not limited to this.

[0338] In some embodiments, steps S3101 and S3102 can be omitted.

[0339] In some embodiments, steps S3101 and S3102 can be executed simultaneously, or the order can be exchanged.

[0340] FIG. 3B is a flow diagram illustrating a method of performing communication by a network device according to an embodiment of the present disclosure. As shown in FIG. 3B, the embodiment of the present disclosure relates to a method of communication, which is performed by a network device. The method of communication includes steps S3201-S3203.

[0341] In step S3201, a configuration set A is sent.

[0342] The optional implementation of step S3201 can refer to the optional implementation of step S2101 in FIG. 2A, other associated parts in the embodiments related to FIG. 2A, and the like, which will not be repeated here.

[0343] In step S3202, a key set A is sent.

[0344] The optional implementation of step S3202 can refer to the optional implementation of step S2102 in FIG. 2A, other associated parts in the embodiments related to FIG. 2A, and the like, which will not be repeated here.

[0345] In step S3203, the key a is determined according to a first rule.

[0346] The optional implementation of step S3203 can refer to the optional implementation of step S2104 in FIG. 2A, the optional implementation of step S2203 in FIG. 2B, the optional implementation of step S2304 in FIG. 2C, other associated parts in the embodiments related to FIG. 2A, other associated parts in the embodiments related to FIG. 2B, other associated parts in the embodiments related to FIG. 2C, and the like, which will not be repeated here. In some embodiments, the network device can determine the key a according to the first rule by itself.

[0347] In some embodiments, the network device can receive the key a sent by the terminal, and at this time, the method of communication can further include receiving first information. The first information is used to indicate the key a.

[0348] The optional implementation of the step of receiving the first information can refer to the optional implementation of step S2106 in FIG. 2A, other associated parts in the embodiments related to FIG. 2A, and the like, which will not be repeated here.

[0349] In some embodiments, steps S3201 and S3202 can be omitted.

[0350] In some embodiments, steps S3201 and S3202 can be executed simultaneously or in an exchanged order.

[0351] FIG. 4A is a flow diagram illustrating a method of performing communication by a terminal according to an embodiment of the present disclosure. As shown in FIG. 4A, the embodiment of the present disclosure relates to a method of communication, which is performed by a terminal. The method of communication includes step S4101.

[0352] In step S4101, the key a associated with the candidate configuration a is determined according to the first rule.

[0353] The optional implementation of step S4101 can refer to the optional implementation of step S2104 in FIG. 2A, the optional implementation of step S2203 in FIG. 2B, the optional implementation of step S2304 in FIG. 2C, other associated parts in the embodiments related to FIG. 2A, other associated parts in the embodiments related to FIG. 2B, other associated parts in the embodiments related to FIG. 2C, which will not be repeated here.

[0354] FIG. 4B is a flow diagram of a method of performing communication on the network device side, according to an embodiment of the present disclosure. As shown in FIG. 4B, the embodiments of the present disclosure relate to a method of communication, which is performed by a network device. The above-mentioned method of communication comprises step S4201.

[0355] In step S4201, the key a is determined according to the first rule.

[0356] The optional implementation of step S4201 can refer to the optional implementation of step S2104 in FIG. 2A, the optional implementation of step S2203 in FIG. 2B, the optional implementation of step S2304 in FIG. 2C, other associated parts in the embodiments related to FIG. 2A, other associated parts in the embodiments related to FIG. 2B, other associated parts in the embodiments related to FIG. 2C, which will not be repeated here.

[0357] FIG. 4C is another flow diagram of a method of performing communication on the terminal side, according to an embodiment of the present disclosure. As shown in FIG. 4C, the embodiments of the present disclosure relate to a method of communication, which is performed by a terminal. The above-mentioned method of communication comprises step S4301.

[0358] In step S4301, the first information is sent.

[0359] The optional implementation of step S4301 can refer to the optional implementation of step S2106 in FIG. 2A and other associated parts in the embodiments related to FIG. 2A, which will not be repeated here.

[0360] In some embodiments, the first information is used to indicate the key a used by the terminal. In some embodiments, the key a is determined by the terminal according to the first rule. Then, the optional implementation of the step of determining the key a by the terminal can refer to the optional implementation of step S2104 in FIG. 2A, the optional implementation of step S2203 in FIG. 2B, the optional implementation of step S2304 in FIG. 2C, other associated parts in the embodiments related to FIG. 2A, other associated parts in the embodiments related to FIG. 2B, other associated parts in the embodiments related to FIG. 2C, which will not be repeated here.

[0361] FIG. 4D is another flow diagram illustrating a method of performing communication on a network device side, according to some embodiments of the present disclosure. As shown in FIG. 4D, some embodiments of the present disclosure relate to a method of communication, performed by a network device. The method of communication includes step S4401.

[0362] In step S4401, first information is received.

[0363] The optional implementation of step S4401 can be found in the optional implementation of step S2106 of FIG. 2A and other associated parts of the embodiments related to FIG. 2A, which will not be repeated here.

[0364] In some embodiments, the first information is used to indicate a key a used by the terminal. In some embodiments, the key a is determined by the terminal according to a first rule. Then, the optional implementation of the step of determining the key a by the terminal can be found in the optional implementation of step S2104 of FIG. 2A, the optional implementation of step S2203 of FIG. 2B, the optional implementation of step S2304 of FIG. 2C, other associated parts of the embodiments related to FIG. 2A, other associated parts of the embodiments related to FIG. 2B, other associated parts of the embodiments related to FIG. 2C, which will not be repeated here.

[0365] In the following, the technical solutions of the embodiments of the present disclosure are exemplarily described through specific implementations.

[0366] In some embodiments, after the terminal experiences a connection failure, the terminal uses a specified key (or key label) for connection recovery according to a rule agreed by a protocol or configured by a network.

[0367] In some embodiments, the method of selecting the key (or key label) by the terminal includes any one of the following:

[0368] Method 1: For a handover failure process of the terminal, the key label corresponding to the candidate configuration used in the handover process and the key label corresponding to the candidate configuration used in the connection recovery process belong to the same key label set.

[0369] In some embodiments, the key label corresponding to the candidate configuration used in the handover process and the key label corresponding to the candidate configuration used in the connection recovery process are the same.

[0370] Method 2: The key corresponding to the candidate configuration used in the connection recovery process is a key that has not been used in the key set corresponding to the candidate configuration.

[0371] Method 3: The key corresponding to the candidate configuration used in the connection recovery process is a key that has not been used in the key set corresponding to the candidate configuration before handover.

[0372] Method 4: The key corresponding to the candidate configuration used in the connection recovery process is the key selected by the terminal according to predefined rules.

[0373] In some embodiments, the predefined rule includes any of the following:

[0374] (1) The key tag used previously + n, where n is a positive integer greater than or equal to 1 as agreed.

[0375] (2) The key tag used before the switch + n, where n is a positive integer greater than or equal to 1.

[0376] Method 5: The terminal selects one key from the key set associated with the candidate configuration, and this key set is used only for the connection recovery process.

[0377] Method 6: The terminal selects one key from the key set corresponding to the cell before the failure occurred, and this key set is only used as the target candidate configuration for the connection recovery process.

[0378] In some embodiments, the terminal may indicate its selected key to the network side (e.g., indicate the NCC value).

[0379] This disclosure includes the following steps: Step 1, the network side sends candidate configuration information to the terminal, which is used for subsequent handover (or cell change, or cell group change) processes. Step 2, after a connection failure occurs, the terminal uses a specified key (or key tag) to restore the connection according to the protocol agreement or network configuration rules.

[0380] In some embodiments, the key corresponding to the candidate configuration can be used in any of the following ways:

[0381] (1) The terminal selects one key (or key tag) from the set of keys (or key tags) configured in the network according to the pre-configured rules for the target candidate configuration.

[0382] In one example, the terminal selects one NCC from the set of NCCs configured in the network for connection restoration.

[0383] (2) The terminal selects the key (or key tag) to use according to the pre-configured rules.

[0384] In one example, the terminal increments the NCC value by 1 each time according to the rules agreed upon in the protocol.

[0385] In some embodiments, connection failure includes any of the following: radio link failure, handover failure, cell change failure, or cell group change failure.

[0386] In some embodiments, a wireless link failure includes any of the following:

[0387] (1) Random access procedure failure (e.g., the number of random access attempts reaches a maximum number).

[0388] (2) RLC entity data transmission failure (e.g., the number of RLC layer data transmission (or retransmission) reaches a maximum number).

[0389] (3) Physical layer out-of-sync failure (e.g., the out-of-sync timer t310 expires, which is started after the number of out-of-sync indications reaches a maximum number.

[0390] In some embodiments, the handover failure comprises any one of:

[0391] (1) Normal handover failure (e.g., the terminal receives a normal handover command and starts a T304 timer, and before the T304 timer expires, the terminal does not successfully complete the access to the target cell indicated by the normal handover command).

[0392] (2) Conditional handover procedure failure (e.g., a conditional triggered mobility procedure).

[0393] (3) Dynamic cell (or cell group) change based handover failure (e.g., an LTM handover procedure).

[0394] In some embodiments, the cell change failure can be an SCell change failure.

[0395] In some embodiments, the cell group change failure can be an MCG cell group change failure, or an SCG cell group change failure.

[0396] In some embodiments, the method for the terminal to select the key (or, the key tag) comprises any one of:

[0397] Method 1: For the terminal handover failure procedure, the key tag corresponding to the candidate configuration used by the handover procedure and the key tag corresponding to the candidate configuration used by the connection recovery procedure belong to the same key tag set.

[0398] In some embodiments, the key tag corresponding to the candidate configuration used by the handover procedure and the key tag corresponding to the candidate configuration used by the connection recovery procedure are the same.

[0399] In an example, the handover procedure uses NCC = 1, and the candidate configuration used by the connection recovery procedure corresponds to NCC = 1.

[0400] In some embodiments, the candidate configuration used by the connection recovery procedure and the candidate configuration used by the handover procedure belong to the same cell set.

[0401] In some embodiments, the candidate configuration used by the connection resume procedure corresponds to the same cell as the candidate configuration used by the handover procedure.

[0402] Method 2: The candidate configuration used by the connection resume procedure corresponds to a key that is not used in the set of keys corresponding to the candidate configuration.

[0403] In an example, the candidate configuration used by the connection resume procedure corresponds to a specific set of keys (e.g., NCC = 1 / 2 / 3), and the terminal used NCC = 1 before the handover, and the terminal used NCC = 2 in the handover procedure. Then the key corresponding to the candidate configuration used by the connection resume procedure is NCC = 2 or 3.

[0404] Method 3: The candidate configuration used by the connection resume procedure corresponds to a key that is not used in the set of keys corresponding to the candidate configuration before the handover.

[0405] In an example, the candidate configuration used by the connection resume procedure corresponds to a specific set of keys (e.g., NCC = 1 / 2 / 3), and the terminal used NCC = 1 before the handover, and the terminal used NCC = 2 in the handover procedure. Then the key corresponding to the candidate configuration used by the connection resume procedure is NCC = 2 or 3.

[0406] Method 4: The candidate configuration used by the connection resume procedure corresponds to a key selected by the terminal according to a predefined rule.

[0407] In an example, the terminal used NCC (old) = 1 in the handover procedure, and the key corresponding to the candidate configuration used by the connection resume procedure is NCC (new) = NCC (old) + 1.

[0408] In some embodiments, the predefined rule includes any one of the following:

[0409] (1) The last used key label + n, where n is a positive integer greater than or equal to 1 agreed upon.

[0410] In an example, the last used (e.g., in the handover procedure) NCC (old) = 1, and the new key is NCC (new) = NCC (old) + 1 = 2.

[0411] (2) The key label used before the handover + n, where n is a positive integer greater than or equal to 1 agreed upon.

[0412] In an example, the key used before the handover NCC (pre-handover) = 1, and the key used in the handover procedure NCC (handover) = NCC (pre-handover) + 1 = 2. Then the new key is NCC (new) = NCC (pre-handover) + 1 = 2.

[0413] Method 5: The terminal selects one key from the key set associated with the candidate configuration configured by the network, and the key set is only used for the connection recovery process.

[0414] In an example, the network side configures the candidate configuration for the terminal in advance, and configures the key set corresponding to the connection recovery for the terminal, which is used by the terminal when using the candidate configuration during the connection recovery. When the key set contains multiple keys, the terminal selects the key in any of the following ways:

[0415] (1) The terminal selects the keys in the key set in the order of the key configuration arrangement of the key set.

[0416] In an example, the key set contains three key values, which are arranged in the key set in turn. When the terminal selects, it selects the key arranged at the first place in the first time according to the arrangement order.

[0417] (2) The terminal selects the keys in the key set in the order of the key values from small to large.

[0418] In an example, the key set contains three key values (such as three NCCs), and the three key values (such as NCC = 1 / 2 / 3) are different. Then the terminal selects NCC = 1 in the first time, NCC = 2 in the second time, and so on according to the order of the key values from small to large.

[0419] Method 6: The terminal selects one key from the key set corresponding to the cell before the failure occurs, and the key set is only used for the target candidate configuration of the connection recovery process.

[0420] In an example, the serving cell of the terminal configures a key set (such as one or more NCC values), which is used by the terminal when using the target candidate configuration during the connection recovery. When the key set contains multiple keys, the terminal selects the key in the same way as method 4.

[0421] In some embodiments, the terminal can indicate the selected key (such as the indicated NCC value) to the network side.

[0422] In an example, the terminal indicates the selected key (such as the selected NCC value) by using the connection configuration completion message, the connection reestablishment request message, or the MAC CE during the connection recovery process.

[0423] The embodiments of the present disclosure further provide a device for implementing any of the above methods, for example, a terminal is provided, and the terminal includes units or modules for implementing the steps performed by the terminal in any of the above methods. For another example, another network device is provided, and the network device includes units or modules for implementing the steps performed by the network device (for example, an access network device, a core network function node, a core network device, etc.) in any of the above methods.

[0424] It should be understood that the division of each unit or module in the above device is only a logical function division, and all or part of the units or modules can be integrated into one physical entity or physically separated in actual implementation. In addition, the units or modules in the device can be implemented in the form of processor calling software: for example, the device includes a processor, the processor is connected with a memory, the memory stores instructions, and the processor calls the instructions stored in the memory to implement any of the above methods or to implement the functions of each unit or module of the device, wherein the processor is a general processor, for example, a central processing unit (CPU) or a microprocessor, and the memory is a memory in the device or a memory outside the device. Alternatively, the units or modules in the device can be implemented in the form of hardware circuit, and the functions of part or all of the units or modules can be implemented by designing the hardware circuit, and the hardware circuit can be understood as one or more processors; for example, in one implementation, the hardware circuit is an application-specific integrated circuit (ASIC), and the functions of part or all of the units or modules are implemented by designing the logical relationship of elements in the circuit; for another example, in another implementation, the hardware circuit is a programmable logic device (PLD), and a field programmable gate array (FPGA) is taken as an example, which can include a large number of logic gate circuits, and the connection relationship between the logic gate circuits is configured by a configuration file, so as to implement the functions of part or all of the units or modules. All units or modules of the above device can be implemented in the form of processor calling software, or all units or modules can be implemented in the form of hardware circuit, or part of the units or modules are implemented in the form of processor calling software, and the remaining part is implemented in the form of hardware circuit.

[0425] In the embodiments of the present disclosure, the processor is a circuit with signal processing capability. In one implementation, the processor can be a circuit with instruction reading and running capability, such as a central processing unit (CPU), a microprocessor, a graphics processing unit (GPU) (which can be understood as a microprocessor), a digital signal processor (DSP), and the like. In another implementation, the processor can implement certain functions through a logical relationship of hardware circuit, and the logical relationship of the hardware circuit is fixed or reconfigurable. For example, the processor is a hardware circuit implemented by an application-specific integrated circuit (ASIC) or a programmable logic device (PLD), such as an FPGA. In the reconfigurable hardware circuit, the processor loads a configuration document to implement the configuration of the hardware circuit. It can be understood that the processor loads instructions to implement the functions of the above part or all units or modules. In addition, it can also be a hardware circuit designed for artificial intelligence, which can be understood as an ASIC, such as a neural network processing unit (NPU), a tensor processing unit (TPU), a deep learning processing unit (DPU), and the like.

[0426] FIG. 5 is a structural schematic diagram of a communication device according to an embodiment of the present disclosure. The communication device can be a terminal or a network device. As shown in FIG. 5, the communication device 5100 can include a determination module 5101. In some embodiments, when the communication device is a terminal, the determination module 5101 is configured to determine a first key associated with a first candidate configuration according to a preconfigured first rule, and the first key is used for the terminal to perform communication connection recovery based on the first candidate configuration. In some embodiments, when the communication device is a network device, the determination module 5101 is configured to determine a first key according to a preconfigured first rule, and the first key is used for the terminal to perform communication connection recovery based on a first candidate configuration associated with the first key.

[0427] In some embodiments, the communication device further includes a transceiving module 5102. In some embodiments, in the case that the communication device is a terminal, the transceiving module 5102 is configured to transmit the first information, the first information being used to indicate the first key. In some embodiments, the transceiving module is further configured to perform at least one of the communication steps (for example, steps S3101, S3102, but not limited thereto) of transmitting and / or receiving performed by the terminal in any of the above methods, which will not be repeated here. In some embodiments, in the case that the communication device is a network device, the transceiving module 5102 is configured to receive the first information, the first information being used to indicate the first key. In some embodiments, the transceiving module is further configured to perform at least one of the communication steps (for example, steps S3201, S3202, but not limited thereto) of transmitting and / or receiving performed by the network device in any of the above methods, which will not be repeated here.

[0428] In some embodiments, the transceiving module described above can include a transmitting module and / or a receiving module. The transmitting module and the receiving module can be separate or integrated together. Alternatively, the transceiving module described above can be mutually replaced with a transceiver.

[0429] FIG. 6 is a structural schematic diagram of a communication device according to an embodiment of the present disclosure. The communication device 6100 can be a terminal or a network device, or can be a chip, a chip system, or a processor supporting the terminal or the network device to implement any of the above methods. The communication device 6100 can be used to implement the methods described in the above method embodiments, and specific reference can be made to the descriptions in the above method embodiments.

[0430] As shown in FIG. 6, the communication device 6100 includes one or more processors 6101. The processor 6101 can be a general-purpose processor or a special-purpose processor, for example, a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, and the central processing unit can be used to control the communication device (for example, a base station, a baseband chip, a terminal device, a terminal device chip, a DU or a CU, etc.), execute programs, and process data of the programs. Optionally, the communication device 6100 is configured to implement any of the above methods. Optionally, the one or more processors 6101 are configured to invoke instructions to cause the communication device 6100 to implement any of the above methods.

[0431] In some embodiments, the communication device 6100 further includes one or more transceivers 6102. When the communication device 6100 includes one or more transceivers 6102, the transceiver 6102 performs at least one of the communication steps (for example, steps S3101, steps S3102, steps S3201, steps S3202, but not limited to) in the above-described method, and the processor 6101 performs at least one of the other steps (for example, steps S3103, steps S3104, steps S3204, but not limited to). In optional embodiments, the transceiver 6102 can include a receiver and / or a transmitter, which can be separate or integrated together. Optionally, the terms transceiver, transceiving unit, transceiver, transceiving circuit, interface circuit, interface, etc. can be replaced with each other, and the terms transmitter, transmitting unit, transmitter, transmitting circuit, etc. can be replaced with each other, and the terms receiver, receiving unit, receiver, receiving circuit, etc. can be replaced with each other.

[0432] In some embodiments, the communication device 6100 further includes one or more memories 6103 for storing data. Optionally, all or part of the memory 6103 can also be outside the communication device 6100. In optional embodiments, the communication device 6100 can include one or more interface circuits 6104. Optionally, the interface circuit 6104 is connected with the memory 6103, and the interface circuit 6104 can be used to receive data from the memory 6103 or other devices, and can be used to send data to the memory 6103 or other devices. For example, the interface circuit 6104 can read the data stored in the memory 6103 and send the data to the processor 6101.

[0433] The communication device 6100 described in the above embodiments can be a network device or a terminal, but the scope of the communication device 6100 described in the present disclosure is not limited thereto, and the structure of the communication device 6100 can not be limited by Figure 6. The communication device can be a standalone device or can be part of a larger device. For example, the communication device can be: 1) a standalone integrated circuit (IC), or a chip, or a chip system or subsystem; (2) a set of one or more ICs, which can optionally include a storage component for storing data, programs; (3) an ASIC, such as a Modem; (4) a module that can be embedded in other devices; (5) a receiver, a terminal device, a smart terminal device, a cellular phone, a wireless device, a handset, a mobile unit, a vehicle-mounted device, a network device, a cloud device, an artificial intelligence device, etc.; (6) others, etc.

[0434] Figure 7 is a structural schematic diagram of a chip according to an embodiment of the present disclosure. For the case where the communication device 6100 can be a chip or a chip system, the structural schematic diagram of the chip 7100 shown in Figure 7 can be referred to, but is not limited thereto.

[0435] The chip 7100 comprises one or more processors 7101. The chip 7100 is configured to perform any of the above methods.

[0436] In some embodiments, the chip 7100 further comprises one or more interface circuits 7102. Optionally, the terms interface circuit, interface, transceiver pin, etc. can replace each other. In some embodiments, the chip 7100 further comprises one or more memories 7103 configured to store data. Optionally, all or part of the memory 7103 can be outside the chip 7100. Optionally, the interface circuit 7102 is connected with the memory 7103, the interface circuit 7102 can be configured to receive data from the memory 7103 or other devices, and the interface circuit 7102 can be configured to send data to the memory 7103 or other devices. For example, the interface circuit 7102 can read the data stored in the memory 7103 and send the data to the processor 7101.

[0437] In some embodiments, the interface circuit 7102 performs at least one of the communication steps (for example, step S3101, step S3201, step S3301, step S3401, but not limited to) of transmitting and / or receiving in the above methods. The interface circuit 7102 performing the communication steps such as transmitting and / or receiving in the above methods means that the interface circuit 7102 performs data interaction between the processor 7101, the chip 7100, the memory 7103 or the transceiver device. In some embodiments, the processor 7101 performs at least one of the other steps (for example, step S3103, step S3104, step S3204, but not limited to).

[0438] The modules and / or devices described in each of the embodiments of the virtual device, the physical device, the chip, etc. can be combined or separated as appropriate. Optionally, part or all of the steps can also be performed by multiple modules and / or devices in cooperation, which is not limited here.

[0439] The embodiments of the present disclosure also propose a storage medium, and the storage medium stores instructions. When the instructions run on the communication device 6100, the communication device 6100 performs any of the above methods. Optionally, the storage medium is an electronic storage medium. Optionally, the storage medium is a computer readable storage medium, but is not limited to this, and it can also be a storage medium readable by other devices. Optionally, the storage medium can be a non-transitory storage medium, but is not limited to this, and it can also be a transitory storage medium.

[0440] The embodiment of the disclosure further provides a program product, which, when executed by the communication device 6100, causes the communication device 6100 to perform any of the above methods. Alternatively, the program product is a computer program product.

[0441] The embodiment of the disclosure further provides a computer program, which, when running on a computer, causes the computer to perform any of the above methods.

[0442] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the application being indicated by the following claims.

[0443] It will be understood that the application is not limited to the precise structures hereinbefore described and illustrated in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the application is indicated by the appended claims, only.

Claims

1. A communication method, performed by a communication device, the method comprising: determining, according to a first rule, a first key associated with a first candidate configuration; and using the first key for the terminal to perform a communication connection recovery based on the first candidate configuration. The first rule comprises one of: determining the first key from a set of keys configured by a network device; determining the first key based on a used key and a first value; and determining the first key based on a used key in a set of keys configured by a network device and a second value. The first rule comprises one of: determining the first key from a set of keys that are not used by the terminal, wherein the first candidate configuration is associated with the set of keys; determining the first key from a set of keys that are not used by the terminal before a cell handover, wherein the first candidate configuration is associated with the set of keys; determining a second key associated with a second candidate configuration as the first key, wherein the second candidate configuration is associated with a set of keys, and the second key is used by the terminal to perform a cell handover based on the second candidate configuration; determining the first key from a set of keys to which the second key belongs, wherein the second candidate configuration is associated with the set of keys, and the second key is used by the terminal to perform a cell handover based on the second candidate configuration; determining the first key from a third set of keys, wherein the first candidate configuration is one of at least one candidate configuration, the at least one candidate configuration is associated with the third set of keys, and the third set of keys is used by the terminal to perform a communication connection recovery procedure; determining the first key from a fourth set of keys, wherein the fourth set of keys is associated with a serving cell used by the terminal before a communication connection recovery, and the fourth set of keys is used by the terminal to perform a communication connection recovery based on the first candidate configuration; determining the first key based on a last used key by the terminal and a first value; determining the first key based on a last used key by the terminal before a cell handover and a first value; determining the first key based on a last used key by the terminal before a cell handover in a fifth set of keys and a second value; determining the first key based on a last used key by the terminal before a cell handover in the fifth set of keys and a second value; wherein the fifth set of keys satisfies at least one of: the fifth set of keys is associated with the first candidate configuration; the fifth set of keys is associated with a second candidate configuration, the second candidate configuration is used by the terminal to perform a cell handover; the fifth set of keys is associated with at least one candidate configuration, the first candidate configuration is one of the at least one candidate configuration, and the fifth set of keys is used by the terminal to perform a communication connection recovery; and the fifth set of keys is associated with a serving cell used by the terminal before a communication connection recovery, and the fifth set of keys is used by the terminal to perform a communication connection recovery based on the first candidate configuration. ​ ​ 2. The method of claim 1, wherein, ​ ​ ​ ​ 3. The method of claim 1 or 2, wherein, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4. The method of claim 3, wherein, The first candidate configuration corresponds to a first cell and the second candidate configuration corresponds to a second cell, which belong to a same cell set; or the first candidate configuration corresponds to the first cell and the second candidate configuration corresponds to the second cell, which are the same; or the first candidate configuration and the second candidate configuration belong to a same configuration set.

5. The method of claim 3 or 4, wherein, The determining the first key comprises one of the following: Determining the first key according to an arrangement order of each key in a sixth key set; Determining the first key according to a numerical value of each key in the sixth key set. The sixth key set is one of the following: the first key set, the second key set, the third key set, and the fourth key set.

6. The method according to any one of claims 1 to 5, wherein, The communication device is a terminal or a network device.

7. The method of claim 6, wherein, The communication device is a terminal, and the method further comprises: Sending first information, which is used to indicate the first key.

8. The method of claim 6, wherein, The communication device is a network device, and the method further comprises: Receiving first information, which is used to indicate the first key.

9. The method of claim 7 or 8, wherein, The first information is carried in a first message, and the first message is at least one of the following: a connection reestablishment request message, a connection configuration completion message, and a medium access control layer message.

10. A communication device, comprising: A determining module configured to determine a first key associated with a first candidate configuration according to a first rule; The first key is used for the terminal to perform a communication connection recovery based on the first candidate configuration.

11. The method of claim 10, wherein, The first rule comprises one of the following: Determining the first key from a key set configured by a network device; Determining the first key based on a used key and a first value; Determining the first key based on a used key in a key set configured by a network device and a second value.

12. The method of claim 10 or 11, wherein, The first rule comprises one of the following: Determining the first key from a key in the first key set that has not been used, wherein the first candidate configuration is associated with the first key set; Determining the first key from a key in the first key set that has not been used before a cell switching of the terminal, wherein the first candidate configuration is associated with the first key set; Determining a second key associated with a second candidate configuration as the first key, wherein the second candidate configuration is associated with the second key set, and the second key is used for the terminal to perform a cell switching based on the second candidate configuration; Determining the first key from a second key set to which the second key belongs, wherein the second candidate configuration is associated with the second key set, and the second key is used for the terminal to perform a cell switching based on the second candidate configuration; Determining the first key from a third key set, wherein the first candidate configuration is one of at least one candidate configuration, the at least one candidate configuration is associated with the third key set, and the third key set is used for the terminal to perform a communication connection recovery process; determining the first key from a fourth key set, wherein the fourth key set is associated with a serving cell used by the terminal before the communication connection recovery, and the fourth key set is used by the terminal to perform the communication connection recovery based on the first candidate configuration; determining the first key based on a last key used by the terminal before the cell switch and the first value; determining the first key based on a last key used by the terminal before the cell switch and the first value; determining the first key based on a last key used by the terminal before the cell switch and the first value; determining the first key based on a last key used by the terminal before the cell switch and the first value; wherein the fifth key set satisfies at least one of the following: the fifth key set is associated with the first candidate configuration; the fifth key set is associated with a second candidate configuration, the second candidate configuration is used by the terminal to perform the cell switch; the fifth key set is associated with at least one candidate configuration, the first candidate configuration is one of the at least one candidate configuration, and the fifth key set is used by the terminal to perform the communication connection recovery; and the fifth key set is associated with a serving cell used by the terminal before the communication connection recovery, and the fifth key set is used by the terminal to perform the communication connection recovery based on the first candidate configuration.

13. The method of claim 12, wherein, the first candidate configuration corresponds to a first cell and the second candidate configuration corresponds to a second cell, the first cell and the second cell belong to a same cell set; or the first candidate configuration corresponds to a first cell and the second candidate configuration corresponds to a second cell, the first cell and the second cell are the same; or the first candidate configuration and the second candidate configuration belong to a same configuration set.

14. The method of claim 12 or 13, wherein, the determining module is configured to perform one of the following: determining the first key according to an arrangement order of each key in a sixth key set; determining the first key according to a numerical value of each key in the sixth key set; wherein the sixth key set is one of the following: the first key set, the second key set, the third key set, and the fourth key set.

15. The method according to any one of claims 10 to 14, wherein, the communication device is a terminal or a network device.

16. The method of claim 15, wherein, the communication device is a terminal, and the communication device further comprises a transceiver module configured to send first information, the first information being used to indicate the first key.

17. The method of claim 15, wherein, the communication device is a network device, and the communication device further comprises a transceiver module configured to receive first information, the first information being used to indicate the first key.

18. The method of claim 16 or 17, wherein, the first information is carried in a first message, and the first message is at least one of the following: a connection reestablishment request message, a connection configuration complete message, and a medium access control layer message.

19. A communication device, comprising: one or more processors; wherein the communication device is configured to perform the communication method of any one of claims 1 to 9.

20. A storage medium, the storage medium storing instructions that, when executed on a communication device, cause the communication device to perform the communication method of any one of claims 1 to 9.

21. A computer program product comprising a computer program which, when executed by a processor, implements the communication method of any one of claims 1 to 9.

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