User equipment radio resource control inactive state handling in radio access network (RAN) decomposition architecture

Abstract

In accordance with an example embodiment of the present invention there is at least a method and an apparatus for performing: determining information based on information released to a radio resource control inactive state, the information includes at least one of: a first integrity key generated by a centralized unit associated with the communication network, or a second integrity key generated by a first distributed unit associated with the communication network; and selecting between using the first integrity key or the second integrity key based on at least one of the radio resource control message or the radio resource control state. Further, to perform determining an information context of the user equipment for integrity protection of the radio resource control message, the information context of the user equipment comprising: a first integrity key and a second integrity key associated with the apparatus, and determining the integrity protection of the device based on the radio resource control message. A selection is made between using the first integrity key or the second integrity key.

Description

Technical Field

[0001] Teachings according to exemplary embodiments of the present invention generally relate to user equipment radio resource control inactivity state handling in a radio access network (RAN) decomposed architecture, and more particularly, to deriving and utilizing additional integrity keys for user equipment radio resource control inactivity state handling in a RAN decomposed architecture in which the radio resource control protocol (RRC) layer is split. Background Art

[0002] This section is intended to provide a background or context for the invention described in the claims. The description herein may include concepts that may be pursued, but not necessarily concepts that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the content described in this section is not prior art to the description and claims in this application, and is not admitted to become prior art by inclusion in this section.

[0003] Certain abbreviations that may appear in the specification and / or drawings are defined as follows:

[0004] CU Centralized Unit

[0005] CP Control Plane

[0006] C-RNTI Connected Mode Radio Network Temporary Identifier

[0007] DU Distributed Unit

[0008] Enc Encryption

[0009] NR New Radio

[0010] gNB 5G Node B

[0011] int integrity

[0012] I-RNTI Inactive Radio Network Temporary Identifier

[0013] MAC-I Message Authentication Code-Integrity

[0014] NCC Next Hop Chain Count

[0015] NG-RAN Next Generation Radio Access Network

[0016] NR New Radio

[0017] RAN Radio Access Network

[0018] RNA Radio Access Network Notification Area

[0019] RNAU Radio Access Network Notification Area Update

[0020] RRC Radio Resource Control Protocol

[0021] UE User Equipment

[0022] UP User Plane

[0023] Xn Xn network interface

[0024] In New Radio (NR), in a Centralized Unit / Distributed Unit (CU / DU) architecture split, the Radio Resource Control (RRC) protocol is terminated in the CU, which handles the bearer termination aspects, including security at the NR PDCP layer (i.e., the CU prepares the final and secure RRC message to the UE). However, the DU is responsible for the lower layers (i.e., providing radio configuration parameters to the CU). In recent internal 6G discussions, some architectural options related to different splits of the RRC functionality between the CU and the DU have been proposed, especially with a view to addressing some of the identified issues with the CU / DU architecture split for 6G systems.

[0025] One such architectural option, where the proposal is to have the CU continue to handle the radio bearer configuration (i.e. RB configuration) aspects, but the RRC is still completely terminated in the DU (rather than the CU in NR). In this option, it is understood that the DU formats the final RRC messages towards the UE, i.e. it hosts the NR PDCP layer for the (multiple) RRC SRBs, and it also terminates the radio level security for the control plane (i.e. (multiple) RRC SRBs).

[0026] Furthermore, this option proposes to have a network-centric RRC-i entity (RRC-internal) which is invisible to the User Equipment (UE) but prepares and handles the radio bearer configuration (i.e. RB configuration) for the PDU session and provides an encapsulation layer using DU to transfer signaling messages back and forth between the CU and the UE.

[0027] Example embodiments of the present invention aim to improve at least these operations. Summary of the invention

[0028] This section contains examples of possible implementations and is not meant to be limiting.

[0029] In one example aspect of the present invention, there is an apparatus, such as a user equipment side apparatus, comprising: at least one processor; and at least one non-volatile memory, comprising computer program code, wherein the at least one non-volatile memory and the computer program code are configured to, together with the at least one processor, enable the apparatus to at least: determine at least one of a first integrity key or a second integrity key associated with a communication network and select between using the first integrity key or the second integrity key based on at least one of a radio resource control message or a radio resource control state.

[0030] In another example aspect of the invention, there is a method comprising: determining at least one of a first integrity key associated with a device or a second integrity key associated with the device, and selecting between using the first integrity key or the second integrity key based on a radio resource control message, and selecting between using the first integrity key or the second integrity key based on at least one of a radio resource control message or a radio resource control state.

[0031] Another example embodiment is an apparatus and method including the apparatus and method of the preceding paragraphs, wherein a second integrity key is selected for use with at least a radio resource control resume request message and the selected integrity key is used to generate an integrity token for at least the radio resource control resume request message, wherein a second integrity key is selected for use with at least a radio resource control release message and the selected integrity key is used to generate an integrity token to verify the validity of the integrity token of the radio resource control release message received from the network, wherein at least one of the determined first integrity key or the second integrity key is based on being released from a connected state, wherein at least one of the first integrity key is generated by a centralized unit associated with the communication network or the second integrity key is generated by a first distributed unit associated with the communication network, wherein the first integrity key and the second integrity key are generated by the first distributed unit and the centralized unit associated with the communication network. The unit is determined in one of the following items: before or after identifying that a radio resource control configuration with a user equipment is to be released and the user equipment is to be scheduled into a radio resource control inactive state, wherein at least one of a first integrity key or a second integrity key is generated by at least one of a first distributed unit or a centralized unit associated with a communication network, wherein generating the second integrity key is based on key material received from the network, wherein the key material is received after the UE is scheduled into the radio resource control inactive state, wherein the key material is received together with a user equipment identifier to be used for the radio resource control inactive state, wherein at least the first integrity key and the second integrity key are one of predetermined by the user equipment or derived by the user equipment, wherein the key material includes at least one of an indication of an integrity protection algorithm and an indication of an algorithm identifier, wherein the integrity token includes resumeMAC-I, wherein the first integrity key is K RRCintA key is provided, and the UE is applying integrity protection to all radio resource control messages except a radio resource control resumption request message using a first integrity key, wherein the selected integrity key comprises a second integrity key, wherein the key material comprises an integrity protection algorithm and an algorithm identifier, the integrity protection algorithm and the algorithm identifier being capable of being fed by the user equipment to a key derivation algorithm to generate, by the user equipment, an integrity token for the radio resource control resumption request message, wherein the information context comprises a security context, the security context comprising a KRRCint_resume for the user equipment, wherein the KRRCint_resume key is used to verify MAC-I validity when the user equipment performs a radio resource control resumption procedure, wherein storing information including at least one of a first integrity key or a second integrity key, wherein the information including at least one of the first integrity key or the second integrity key is stored, wherein the storing is based on a validity timer, wherein upon expiration of the validity timer, the information context is discarded, wherein the validity timer is configured by the first distributed unit as T_INACTIVE_DU, wherein an integrity token for at least one radio resource control restoration request message is generated using the selected integrity key, and wherein the integrity token for at least one radio resource control restoration request message received from a user equipment is verified using the selected integrity key, and / or wherein the user equipment has not determined that it has moved to an area of ​​a communications network controlled by the apparatus.

[0032] A non-transitory computer readable medium stores program code, which is executed by at least one processor to perform at least the method described in the above paragraphs.

[0033] In another example aspect of the invention, there is an apparatus comprising: means for determining at least one of a first integrity key associated with a communication network or a second integrity key associated with the communication network, and means for selecting between using the first integrity key or the second integrity key based on at least one of a radio resource control message or a radio resource control state.

[0034] According to an example embodiment as described in the above paragraphs, at least means for storing, selecting, and using include a network interface, and computer program code stored on a computer readable medium and executed by at least one processor.

[0035] In another exemplary aspect of the present invention, there is an apparatus, such as a network-side apparatus, comprising: at least one processor; and at least one memory, comprising computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, enable the apparatus to at least: generate and store, by a network node of a communication network, an information context for a user equipment, at least a first integrity key and a second integrity key for integrity protection of a radio resource control message of the user equipment, and select between using the first integrity key or the second integrity key based on the radio resource control message, and use the selected integrity key to verify an integrity token for at least one radio resource control recovery request message received from the user equipment.

[0036] In another example aspect of the invention, there is a method comprising: storing an information context of a user equipment for integrity protection of a radio resource control message, the information context comprising a first integrity key and a second integrity key associated with the device, and selecting between using the first integrity key or the second integrity key based on the radio resource control message, and selecting between using the first integrity key or the second integrity key based on the radio resource control message.

[0037] Another example embodiment is an apparatus and method including the apparatus and method of the preceding paragraphs, wherein the first integrity key and the second integrity key are determined by a first distributed unit and a centralized unit associated with the apparatus in one of the following: before or after identifying that a radio resource control configuration with the user equipment is to be released and the user equipment is to be scheduled into a radio resource control inactive state, wherein at least one of the first integrity key or the second integrity key is generated by at least one of the first distributed unit or the centralized unit associated with the communications network, wherein generating the second integrity key is based on keying material received from the network, wherein the keying material is received after the UE is scheduled into the radio resource control inactive state, wherein the keying material is received together with a user equipment identifier to be used for the radio resource control inactive state, wherein at least the first integrity key and the second integrity key are one of predetermined by the user equipment or derived by the user equipment, wherein the keying material comprises at least one of an indication of an integrity protection algorithm and an indication of an algorithm identifier, wherein the integrity token comprises resumeMAC-I, wherein the first integrity key is K RRCinta key, and the UE applies integrity protection to all radio resource control messages except the radio resource control resumption request message using the first integrity key, wherein the selected integrity key comprises a second integrity key, wherein the key material comprises an integrity protection algorithm and an algorithm identifier, the integrity protection algorithm and the algorithm identifier can be fed by the user equipment to a key derivation algorithm to generate, by the user equipment, an integrity token for the radio resource control resumption request message, wherein the information context comprises a security context, the security context comprises a KRRCint_resume key for the user equipment, wherein the KRRCint_resume key is used to verify the validity of resumeMAC-I when the user equipment performs a radio resource control resumption procedure, wherein information comprising at least one of the first integrity key or the second integrity key is stored, wherein the storing is based on a validity timer, wherein upon expiration of the validity timer, the information context is discarded, wherein the validity timer is configured by the first distributed unit to be T_INACTIVE_DU, wherein the user equipment has not determined that it has moved to an area of ​​the communication network controlled by the apparatus, wherein the information context is not yet determined by the apparatus to have ... A second distributed unit of the apparatus receives a user equipment context acquisition request and a radio resource control resumption request from a user equipment, wherein the radio resource control resumption request includes a resumeMAC-I and an indication of an integrity token, wherein the user equipment is not identified based on the second distributed unit, wherein the radio resource control resumption request including the resumeMAC-I is sent to a centralized unit, wherein the received resumeMAC-I is sent using a stored key received from the centralized unit based on the second distributed unit identifying the user equipment, wherein in response to the request from the user equipment, the information context is delivered to the second distributed unit using the centralized unit, wherein an integrity token for at least one radio resource control resumption request message received from the user equipment is verified using the selected integrity key, wherein at least one of the first integrity key or the second integrity key is generated by at least one of the first distributed unit or the centralized unit associated with the communication network, and / or wherein the first integrity key and the second integrity key are determined by the first distributed unit and the centralized unit associated with the apparatus in one of the following items: before or after identifying that a radio resource control configuration with the user equipment is to be released and the user equipment is to be scheduled to a radio resource control inactive state.

[0038] A non-transitory computer readable medium storing program code, the program code being executed by at least one processor to perform at least the method as described in the above paragraphs.

[0039] In another example aspect of the invention, there is an apparatus comprising: means for storing an information context of a user equipment for integrity protection of a radio resource control message, the information context comprising a first integrity key and a second integrity key associated with the apparatus, and selecting between using the first integrity key or the second integrity key based on the radio resource control message, and means for selecting between using the first integrity key or the second integrity key based on the radio resource control message.

[0040] According to the example embodiments described above, at least means for storing, selecting, and using include a network interface, and computer program code stored on a computer-readable medium and executed by at least one processor.

[0041] A communication system includes a network side device and a user equipment side device for performing the above operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The above and other aspects, features and advantages of various embodiments of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings, in which like reference symbols are used to represent similar or equivalent elements. The accompanying drawings are shown to facilitate a better understanding of the embodiments of the present disclosure and are not necessarily drawn to scale. In the accompanying drawings:

[0043] Figure 1 The proposed RRC architecture splitting options for 6G are shown;

[0044] Figure 2A shows a RRCResumeRequest1 message; and

[0045] Figure 2B UE context acquisition for inter-gNB recovery as defined in section 9.2.1.13 UE Context Information – Retrieve UEContext Response of TS 38.423 is shown;

[0046] Figure 3 The key hierarchy generation in 5GS is shown, and the new key derivation (i.e., KRRCint_resume) is shown;

[0047] FIG4 shows an implementation of the proposed method according to an example embodiment of the present invention;

[0048] Figure 5 shows a high-level block diagram of various devices used to perform various aspects of the invention; and

[0049] Fig. 6A and Figure 6BEach illustrates a method that may be performed by an apparatus according to an example embodiment of the present invention. DETAILED DESCRIPTION

[0050] In example embodiments of the present invention, at least one method and apparatus are presented for enabling a user equipment radio resource control to derive and utilize additional integrity keys for handling inactivity states in an architecture such as a radio access network (RAN) split architecture.

[0051] Similarly as mentioned above, in New Radio (NR), in a Centralized Unit / Distributed Unit (CU / DU) architecture split, the Radio Resource Control (RRC) protocol is terminated at the CU, which handles the bearer termination aspects, including security at the NR PDCP layer (i.e., the CU prepares the final and secure RRC messages to the UE). However, the DU is responsible for the lower layers (i.e., providing radio configuration parameters to the CU). In recent internal 6G discussions, some architectural options related to different splits of the RRC functionality between the CU and DU have been proposed, especially with a view to addressing some of the identified issues with the CU / DU architecture split for 6G systems.

[0052] One such architectural option, where the proposal is to have the CU continue to handle the radio bearer configuration (i.e. RB configuration) aspects, but the RRC is still completely terminated in the DU (rather than the CU in NR). In this option, it is understood that the DU formats the final RRC messages towards the UE, i.e. it hosts the NR PDCP layer for the (multiple) RRC SRBs, and it also terminates the radio level security for the control plane (i.e. (multiple) RRC SRBs).

[0053] Furthermore, this option proposes to have a network-centric RRC-i entity (RRC-internal) which is invisible to the UE but prepares and processes the radio bearer configuration (i.e. RB configuration) for the PDU session and provides an encapsulation layer using the DU to transfer signaling messages back and forth between the CU and the UE. Of course, the RRC protocol on the UE side is not affected by this RRC-i (avoiding the complex discussions during the standardization phase on how to split and specify the RRC messages and procedures in the RRC specification, where a dual signaling architecture assumption was proposed, such as in the alternative A3 option, where the network and UE state RRC includes a dual RRC concept (RRC-H and RRC-L).

[0054] RRC INACTIVE is a feature in NR RRC where the UE enters a suspended RRC state, which is mainly guided by power saving due to user plane inactivity. RRC INACTIVE requires the network to provide an identifier called I-RNTI, which helps to unambiguously identify the UE in a given PLMN. During the recovery phase, the UE formats the RRC recovery request message in the uplink with the allocated I-RNTI and attaches the resumeMAC-I (i.e. integrity token).

[0055] RRC inactive mode is roughly the same as RRC idle mode, except that the UE will store the RRC context for a period of time. After some timers expire, the UE will delete the context and move to RRC idle mode. According to the standard at the time of this application, in response to a request to resume the RRC connection, the network can resume the suspended RRC connection and send the UE to RRC_CONNECTED, or reject the request for resumption and send the UE to RRC_INACTIVE (with a waiting timer), or directly re-suspend the RRC connection and send the UE to RRC_INACTIVE, or directly release the RRC connection and send the UE to RRC_IDLE, or instruct the UE to initiate NAS level recovery (in this case, the network sends an RRC setup message).

[0056] Figure 2A The RRCResumeRequest1 message is shown. It should be noted that there is a RRCResumeRequest1-IEs sequence in the message, which has resumeIdentity I-RNTI-Value and resumeM-I with a bit string size of (16).

[0057] This includes:

[0058] 1> resumeMAC-I Set to the 16 least significant bits of the MAC-I calculated as follows:

[0059] 2> ASN.1 encoded according to clause 8 (i.e. multiples of 8 bits)

[0060] VarResumeMAC-Input ;

[0061] 2> use UE Inactive AS Context K RRCint Key and a previously configured integrity protection algorithm; and

[0062] 2> Set all input bits for COUNT, BEARER, and DIRECTION to binary 1.

[0063] In NR RRC with CU / DU split architecture, the resume identifier is assigned by the CU. resumeMAC-I is calculated by the UE using: {VarResumeMAC-Input;, K RRCint}:

[0064] - In NR RRC, K RRCint Generated at the CU (because it terminates NRPDCP for (multiple) RRC SRBs);

[0065] - In NR RRC, VarResumeMAC-Input; based on the following combination {source cell PCI, source cell C-RNTI, target cell identity read from broadcast on SIB1 in the cell where the UE recovers}.

[0066] In the standard at the time of this application, the handling of security keys at the gNB and UE upon RRC state transition from RRC Inactive to RRC Connected is described. Key excerpts / summary aspects are provided as follows:

[0067] When the UE attempts to resume, the RRCResumeRequest message shall include the I-RNTI for context identification and the ResumeMAC-I / shortResumeMAC-I. The latter is a 16-bit message authentication token that the UE shall calculate using the integrity algorithm (NIA or EIA) in the stored AS security context, which was negotiated between the UE and the source gNB or ng-eNB, and the current K RRCint With some known input:

[0068] o KEY: should be set to the current KEY RRCint ;

[0069] o BEARER: All its bits shall be set to 1;

[0070] o DIRECTION: its bit shall be set to 1;

[0071] o COUNT: All its bits shall be set to 1;

[0072] o MESSAGE: should be set to VarResumeMAC-Input / VarShortInactiveMAC-Input, such as TS

[0073] TS 38.331

[22] for gNB and TS 36.331

[69] for ng-eNB, with the following inputs:

[0074] Source PCI, target Cell-ID, source C-RNTI.

[0075] In an example embodiment of the present invention, it is assumed that the architecture option is adopted in 6G (eg Figure 1 In the context of the present invention, it is worth noting that in this option, According to an exemplary embodiment of the present invention, for (multiple) RRC NR PDCP of SRB can be terminated in DU, which means AS security is handled in DU .

[0076] A UE in RRC INACTIVE state may attempt to resume the RRC connection in the last serving DU (denoted here as intra-DU recovery) or through a different DU or even a different CU (denoted here as inter-DU and inter-CU recovery). As described in the background section, RRC INACTIVE recovery of the UE proceeds smoothly in inter-DU / CU recovery, assuming that the RRC layer is terminated in the CU (i.e., the CU has all security materials to process and verify the resumeMAC-I received from the UE at the time of recovery).

[0077] Using RRC architecture alternative, AS security terminates at DU , in the above scenario where the UE resumes in a DU different from the last served DU (i.e. the one in which the UE was scheduled to RRC INACTIVE), CU cannot verify alone resumeMAC-I . Here is the CU Alternative It is the DU that contacted the last service (hereinafter also referred to as the source DU) and requests MAC-I authentication (and possibly fetching the UE context stored at the DU).

[0078] The overall cost is 4 F1 messages:

[0079] o The target DU forwards the RRC recovery request to the CU (1 message);

[0080] o CU contacts the source DU to authenticate the UE (1 message, 1 message);

[0081] o CU contacts the target DU with the authentication result (1 message)

[0082] Assuming a modest delay of 5 ms for one-way F1 messages, the delay for inactivity recovery will be increased by 20 ms due to this process, which is undesirable.

[0083] The key hierarchy generation in 5GS is defined in TS 33.501, allowing the derivation of AS keys (i.e. KgNB, KRRCint, KRRCenc, KUPint and KUPenc). Such derivation is used in the present invention.

[0084] Figure 2BUE context retrieval for inter-gNB recovery as defined in section 9.2.1.13 UE Context Information – Retrieve UEContext Response of TS 38.423 is shown.

[0085] UE context retrieval for inter-gNB recovery is defined in TS 38.423 clause 9.2.1.13 UE Context Information – Retrieve UE Context Response.

[0086] The present invention proposes a method for the CU to derive and utilize an additional integrity key for integrity protection in the architecture options described herein, so that the CU can verify the resumeMAC-I received from the UE during the RRC resume procedure (initiated by the UE through a cell with a different DU from its last served DU). Such a key is denoted as K RRCint_resume In addition to the existing K RRCint In addition to being used by the network, in this architecture option, K RRCint Used by the DU for integrity protection of RRC messages. Likewise, the UE must derive and use the same key when generating resumeMAC-I.

[0087] Before describing in detail exemplary embodiments of the present invention, Figure 5 , which is used to illustrate a simplified block diagram of various electronic devices that are suitable for use in practicing the example embodiments of this invention.

[0088] Figure 5 A block diagram of one possible, non-limiting exemplary system in which example embodiments of the present invention may be practiced is shown. Figure 5 In the embodiment, the user equipment (UE) 10 and the Figure 5 Wireless network 1 or network 1 in wireless communication. Figure 5 The wireless network 1 or network 1 in the present invention may include a communication network, such as a mobile network, for example, the mobile network 1 or the first mobile network disclosed herein. Figure 5 Any reference to wireless network 1 in the specification may be considered a reference to any wireless network disclosed herein. Figure 5 The wireless network 1 in the embodiment may also include hard-wired features that may be required by the communication network. A UE is a wireless, usually mobile device that can access a wireless network. A UE may be, for example, a mobile phone (or a so-called "cellular" phone) and / or a computer with mobile terminal functions. For example, a UE or mobile terminal may also be a portable, pocket-sized, handheld, computer-embedded or vehicle-mounted mobile device, and performs voice signaling and / or data exchange with a RAN.

[0089] UE 10 comprises one or more processors DP 10A, one or more memories MEM 10B, and one or more transceivers TRANS 10D interconnected by one or more buses. Each transceiver in one or more transceivers TRANS10D comprises a receiver and a transmitter. One or more buses may be address, data, or control buses, and may comprise any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, optical fiber or other optical communication devices, etc. One or more transceivers TRANS10D may optionally be connected to one or more antennas to communicate with NN 12 and NN 13 respectively. One or more memories MEM 10B comprise computer program code PROG 10C. UE 10 communicates with NN12 and / or NN 13 via wireless link 11 or 16.

[0090] NN 12 (NR / 5G Node B, Evolved NB or LTE equipment) is a network node, such as a primary or secondary node base station (e.g., for NR or LTE long term evolution), which is connected to a network device such as Figure 5 12 provides access to the wireless network 1 to wireless devices such as UE 10. NN 12 includes one or more processors DP 12A, one or more memories MEM 12B, and one or more transceivers TRANS12D interconnected by one or more buses. According to an example embodiment, these TRANS12D may include X2 and / or Xn interfaces for performing example embodiments of the present invention. Each of the one or more transceivers TRANS12D includes a receiver and a transmitter. The one or more transceivers TRANS12D may optionally be connected to one or more antennas to communicate with UE 10 via at least link 11. One or more memories MEM12B and computer program code PROG 12C are configured to cause NN 12 to perform one or more operations as described herein together with one or more processors DP 12A. NN 12 may communicate with another gNB or eNB or a device such as NN 13, such as via link 16. In addition, link 11, link 16, and / or any other link may be wired or wireless or both, and may implement, for example, an X2 or Xn interface. In addition, link 11 and / or link 16 may be connected through other network devices, such as, but not limited to, Figure 5 The NN 12 may include NCE / MME / SGW / UDM / PCF / AMF / SMF / LMF 14 devices. The NN 12 may perform functions of an MME (Mobility Management Entity) or an SGW (Serving Gateway), such as user plane functions and / or access management functions for LTE and similar functions for 5G.

[0091] NN 13 may be associated with a mobile function device (such as AMF or SMF), and in addition, NN 13 may include an NR / 5G node B or a possible evolved NB base station, such as a master node base station or a secondary node base station (for example, for NR or LTE long term evolution), which communicates with a device (such as NN 12 and / or UE 10) and / or a wireless network 1. NN 13 includes one or more processors DP 13A, one or more memories MEM 13B, one or more network interfaces, and one or more transceivers TRANS 13D interconnected by one or more buses. According to an example embodiment, these network interfaces of NN 13 may include X2 and / or Xn interfaces for performing example embodiments of the present invention. Each transceiver in the one or more transceivers TRANS13D includes a receiver and a transmitter, which may be optionally connected to one or more antennas. One or more memories MEM 13B include computer program code PROG 13C. For example, one or more memories MEM 13B and computer program code PROG 13C are configured to enable NN 13 to perform one or more operations as described herein together with one or more processors DP 13A. NN 13 may communicate with another mobility function device and / or eNB (such as NN 12 and UE 10 or any other device) using, for example, link 11 or link 16 or another link. Figure 5 As shown in FIG. 1 , link 16 may be used for communication between NN 12 and NN 13. These links may be wired or wireless or both, and may implement, for example, an X2 or Xn interface. In addition, as described above, link 11 and / or link 16 may pass through other network devices, such as but not limited to NCE / MME / SGW devices, such as Figure 5 NCE / MME / SGW / UDM / PCF / AMF / SMF / LMF 14.

[0092] Figure 5 The one or more buses of the device may be address, data, or control buses and may include any interconnection mechanism, such as a series of wires on a motherboard or integrated circuit, optical fiber, or other optical communication device, wireless channel, etc. For example, one or more transceivers TRANS12D, TRANS13D, and / or TRANS10D may be implemented as a remote radio head (RRH), where other elements of the NN 12 are physically located at a different location from the RRH, and these devices may include one or more buses that may be partially implemented as fiber optic cables to connect the other elements of the NN 12 to the RRH.

[0093] It should be noted that although Figure 5Network nodes such as NN 12 and NN 13 are shown, but any of these nodes may be incorporated or merged into an eNodeB or eNB or gNB, such as for LTE and NR, and will still be configurable to perform the example embodiments of the present invention.

[0094] It should also be noted that the description herein indicates that a "cell" performs functions, but it should be clear that the gNB forming the cell and / or the user equipment and / or the mobility management function device that will perform these functions. In addition, the cell constitutes part of the gNB, and each gNB can have multiple cells.

[0095] The wireless network 1 or any network it may represent may or may not include NCE / MME / SGW / UDM / PCF / AMF / SMF / LMF 14, which may include (NCE) network control element functions, MME (mobility management entity) / SGW (serving gateway) functions, and / or serving gateway (SGW), and / or MME (mobility management entity), and / or SGW (serving gateway) functions, and / or user data management functions (UDM), and / or PCF (policy control) functions, and / or access and mobility management functions (AMF) functions, and / or session management (SMF) functions, and / or location management functions (LMF), and / or authentication server (AUSF) functions, and it provides connection to another network (such as a telephone network and / or a data communication network (e.g., the Internet)), and it is configured to perform any 5G and / or NR operations in addition to or instead of other standard operations at the time of this application. NCE / MME / SGW / UDM / PCF / AMF / SMF / LMF 14 may be configured to perform operations according to an exemplary embodiment of the present invention in LTE, NR, 5G, and / or any standard-based communication technology being implemented or discussed at the time of this application. In addition, it should be noted that operations according to an exemplary embodiment of the present invention performed by NN 12 and / or NN 13 may also be performed at NCE / MME / SGW / UDM / PCF / AMF / SMF / LMF 14.

[0096] The NCE / MME / SGW / UDM / PCF / AMF / SMF / LMF 14 includes one or more processors DP 14A, one or more memories MEM 14B, and one or more network interfaces (N / WI / F) interconnected by one or more buses coupled to the link 13 and / or the link 16. According to an exemplary embodiment, these network interfaces may include X2 and / or Xn interfaces for performing exemplary embodiments of the present invention. The one or more memories MEM 14B include computer program code PROG 14C. The one or more memories MEM 14B and the computer program code PROG 14C are configured to, together with the one or more processors DP 14A, cause the NCE / MME / SGW / UDM / PCF / AMF / SMF / LMF 14 to perform one or more operations that may be required to support operations according to exemplary embodiments of the present invention.

[0097] It should be noted that the NN 12 and / or the NN 13 and / or the UE 10 may be configured (e.g., based on standard implementations, etc.) to perform the functions of a location management function (LMF). The LMF functions may be embodied in any of these network devices or other devices associated with these devices. In addition, the LMF (such as Figure 5 The MME / SGW / UDM / PCF / AMF / SMF / LMF 14 of the LMF) may be co-located with the UE 10 as described at least below, so that Figure 5 NN 12 and / or NN 13 are separated to perform operations according to example embodiments of the present invention as disclosed herein.

[0098] The wireless network 1 can implement network virtualization, which is the process of combining hardware and software network resources and network functions into a single software-based management entity (virtual network). Network virtualization involves platform virtualization, usually combined with resource virtualization. Network virtualization is classified into external virtualization and internal virtualization. External virtualization combines many networks or parts of networks into a virtual unit, and internal virtualization provides network-like functions for software containers on a single system. Please note that the virtualized entity produced by network virtualization is still implemented using hardware (such as processors DP10, DP12A, DP13A, and / or DP14A and memories MEM 10B, MEM 12B, MEM 13B, and / or MEM 14B) to some extent, and such virtualized entity will produce technical effects.

[0099] Computer readable memories MEM 12B, MEM 13B, and MEM 14B may be of any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Computer readable memories MEM 12B, MEM 13B, and MEM 14B may be components for performing storage functions. Processors DP10, DP12A, DP13A, and DP14A may be of any type suitable for the local technical environment and, as non-limiting examples, may include one or more of the following: a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Processors DP10, DP12A, DP13A, and DP14A may be components for performing functions, such as controlling UE 10, NN 12, NN 13, and other functions as described herein.

[0100] In general, various embodiments of any of these devices may include, but are not limited to, cellular telephones, such as smart phones with wireless communication capabilities, tablet computers, personal digital assistants (PDAs), portable computers with wireless communication capabilities, image capture devices (such as digital cameras with wireless communication capabilities), gaming devices with wireless communication capabilities, music storage and playback devices with wireless communication capabilities, Internet devices allowing wireless Internet access and browsing, tablet computers with wireless communication capabilities, and portable units or terminals incorporating combinations of these functions.

[0101] Furthermore, various embodiments of any of these devices may be used with a UE vehicle, an aerial platform station, or any other such node associated with a terrestrial network or any drone type radio or radio in an aircraft or other airborne vehicle.

[0102] Fig. 4 shows an implementation of the proposed method according to an exemplary embodiment of the present invention.

[0103] As shown in Figure 4, the implementation includes the following steps:

[0104] Step 1: The UE is in the area controlled by DU-1 (UE does not know this, but it is important to explain this because the present invention also includes the network part);

[0105] Step 2: The network decides to put the UE into RRC_INACTIVE state;

[0106] Step 3: CU allocates I-RNTI and provides key material (e.g. integrity protection algorithm and algorithm ID, which can be fed into the key derivation algorithm by the UE and derive KRRCint_resume), and sends it to DU-1 to send it to the UE;

[0107] Step 3A: CU stores UE context (including I-RNTI, radio capabilities, security context, including KRRCint_resume key;

[0108] Step 4-5: UE receives and stores the information, and moves to RRC_INACTIVE:

[0109] -Step 4B: Optional embodiment: If the UE returns and resumes via the last serving DU (DU-1), DU-1 may also store the UE context and KRRCint_resume key in preparation for locally verifying resumeMAC-I. Such storage may be temporary based on a validity timer, after which the context may be discarded. This may be controlled by an associated timer configured for the DU (e.g., T_INACTIVE_DU, e.g., 10 seconds or 2 minutes):

[0110] o This step is attractive for semi-stationary returning UEs, which can initiate multiple recovery / small data transfer procedures in the last serving DU;

[0111] Step 6: Assume that the UE is mobile and moves out of the coverage area of ​​DU-1 (again, the UE is not aware of DU-1 or DU-2, but this is only illustrated to show the network side aspects related to the present invention);

[0112] Step 7: When the connection recovery is triggered (for example, there is data or signaling in the UE buffer), the UE initiates the recovery process. RRCint_resume Generate resumeMAC-I;

[0113] Step 8: UE sends RRCResumeRequest including resumeMAC-I to DU-2 via the cell of DU-2;

[0114] Step 9: DU-2 cannot identify the UE, so it sends a UE Context Acquisition Request to the CU along with the RRCResumeRequest received by the UE, including resumeMAC-I; and

[0115] Step 10: The CU may identify the UE based on the I-RNTI and verify the received resumeMAC-I, which will be used in the inactive and / or idle state;

[0116] Then, if the MAC-I verification succeeds, the CU may deliver the UE context to DU-2 in response to the request.

[0117] It should be noted that the inventive portion in FIG. 4 is marked as “ creativity ". These creative parts include: in step 3 of FIG. 4, the CU schedules the UE to enter RRC_INACTIVE (I-RNTI, key material generation K RRCint_resume , as shown in step 3A of FIG4 , CU stores K RRCint_resume UE context, as shown in step 4 of Figure 4, DU-1 sends key material to the UE to generate K RRCint_resume , as shown in Figure 4 Figure 4B As shown in the figure, the DU-1 storage includes K RRCint_resume UE context for validity timer T, as shown in step 7 of FIG. 4, the UE sets the validity timer T based on K RRCint_resume Generate resumeMAC-I, as shown in step 10 of Figure 4, CU based on K RRCint_resume Perform the verification of resumeMAC-I, as shown in step 13 of Figure 4, DU-2 sends a discard K to the UE. RRCint_resume As indicated in step 14 of FIG. 4 , the UE retains or discards K RRCint_resume .

[0118] Additional Examples:

[0119] Additionally or alternatively, the UE may be provided with an area in which the UE may generate a resumeMAC-I (K RRC_int or K RRCint_resume ) using any integrity protection key in this area:

[0120] oSuch an area can be defined as RNA and can contain all cells belonging to the last serving DU (DU-1);

[0121] o In one example, such a region is provided in step 4 above;

[0122] o In such a case, the DU-1 receiving the ResumeMAC-I from the UE can verify whether the resumeMAC-I verification was successful using either key, since it stores K RRC_int and K RRCint_resume ;as well as

[0123] o In one option, the UE shall use K RRC_int , use K outside the configured area RRCint_resume .

[0124] UE and DU derive and apply the existing Krrc_int Perform integrity protection on RRC messages that require integrity protection (i.e., UE / DU based on K rrc_int to calculate the MAC-I, which will be included in the PDCP PDU encapsulating the RRC message for integrity protection).

[0125] In one option, the UE shall use K within the configured region when applying integrity protection of RRC messages. RRCint_resume .

[0126] It should be noted that if Figure 3 The bottom of FIG. 1 shows a K according to an exemplary embodiment of the present invention. RRCintResume The key is obtained. It should be noted that the K RRCintResume The key is obtained in Figure 3 Marked as " creativity ”.

[0127] The keys used for RRC signaling include:

[0128] -K RRCint It is from K gNB The derived key should only be used to exploit

[0129] Protection of RRC signaling with a certain integrity algorithm;

[0130] -K RRCenc It is from K gNB The derived key should only be used to protect RRC signalling using the specified encryption algorithm; and

[0131] -K RRCint_resume It is from K gNB The derived key shall only be used during RRC recovery from RRC_INACTIVE for the generation of Resume MAC-I using a specific integrity algorithm.

[0132] Advantages of operation according to an exemplary embodiment of the present invention include that when the proposed solution is applied, verification of ResumeMAC-I requires only 2 F1 messages (2 messages between CU-DU2) instead of 4 (2 messages between CU-DU2 + 2 messages between CU and DU1), thereby reducing signaling overhead and latency for the recovery process.

[0133] Fig. 6A and Figure 6B Each illustrates a method according to an example embodiment of the present invention that may be performed by an apparatus.

[0134] Fig. 6AThe diagram illustrates operations that may be performed by an apparatus, such as, but not limited to, a user equipment device (e.g., Figure 5 UE 10 in FIG. Fig. 6A As shown in step 610 of , information including at least one of a first integrity key or a second integrity key associated with a communication network is determined. Fig. 6A As shown in step 620, based on at least one of a radio resource control message or a radio resource control state, a selection is made between using the first integrity key or the second integrity key.

[0135] According to an example embodiment as described in the above paragraphs, wherein a second integrity key is selected for at least one radio resource control restoration request message, and the integrity token for at least the radio resource control restoration request message is generated using the selected integrity key.

[0136] According to an example embodiment as described in the above paragraphs, wherein a second integrity key is selected for use with at least a radio resource control release message, and an integrity token is generated using the selected integrity key to verify the validity of the integrity token of the radio resource control release message received from the network.

[0137] According to an example embodiment as described in the above paragraph, wherein at least one of the determined first integrity key or the second integrity key is based on being released from a connected state.

[0138] According to an example embodiment as described in the above paragraphs, wherein at least one of the first integrity keys is generated by a centralized unit associated with the communication network, or the second integrity key is generated by a first distributed unit associated with the communication network.

[0139] According to an example embodiment as described in the above paragraphs, the first integrity key and the second integrity key are determined by a first distributed unit and a centralized unit associated with the apparatus in one of the following items: before or after identifying that a radio resource control configuration with a user equipment is to be released and the user equipment is to be scheduled to a radio resource control inactive state.

[0140] According to an example embodiment as described in the above paragraphs, wherein generating the second integrity key is based on key material received from the network.

[0141] According to an example embodiment as described in the above paragraphs, wherein the key material is received after the user equipment is scheduled into a radio resource control inactive state.

[0142] According to an example embodiment as described in the above paragraphs, wherein key material is received together with a user equipment identifier to be used for the radio resource control inactive state.

[0143] According to an example embodiment as described in the above paragraphs, at least the first integrity key and the second integrity key are one of predetermined by the user equipment or derived by the user equipment.

[0144] According to an example embodiment as described in the above paragraph, wherein the key material comprises at least one of: an indication of an integrity protection algorithm, and an indication of an algorithm identifier.

[0145] According to an example embodiment as described in the above paragraphs, wherein the integrity token comprises resumeMAC-I.

[0146] According to an example embodiment as described in the above paragraphs, wherein the first integrity key is K RRCint The user equipment is applying integrity protection to all radio resource control messages except the radio resource control resumption request message using the first integrity key.

[0147] According to an example embodiment as described in the above paragraph, wherein the selected integrity key comprises a second integrity key.

[0148] According to an example embodiment as described in the above paragraphs, wherein the key material comprises an integrity protection algorithm and an algorithm identifier, the integrity protection algorithm and the algorithm identifier can be fed by the user equipment to a key derivation algorithm to generate, by the user equipment, an integrity token for a radio resource control recovery request message.

[0149] According to an example embodiment as described in the above paragraphs, wherein the information context comprises a security context, the security context comprises a KRRCint_resume key for the user equipment.

[0150] According to the example embodiment as described in the above paragraphs, wherein when the user equipment receives a radio resource control release message from the network, the KRRCint_resume key is used to verify the MAC-I validity.

[0151] According to an example embodiment as described in the above paragraphs, wherein information comprising at least one of the first integrity key or the second integrity key is stored, and wherein the storing is based on a validity timer, wherein upon expiration of the validity timer the information context is discarded.

[0152] According to an example embodiment as described in the above paragraphs, wherein the validity timer is configured by the first distributed unit as T_INACTIVE_DU.

[0153] According to an example embodiment as described in the above paragraphs, wherein the user equipment has not yet determined that it has moved to an area of ​​the communication network controlled by the apparatus.

[0154] According to the example embodiments as described in the above paragraphs, the integrity token for at least the radio resource control resumption request message is generated using the selected integrity key.

[0155] A non-transitory computer readable medium (such as Figure 5 MEM 10B in the storage device stores program code (such as Figure 5 PROG10C in, the program code is executed by at least one processor (such as Figure 5 DP 10A) in is executed to perform at least the operations described in the above paragraphs.

[0156] According to an exemplary embodiment of the present invention as described above, there is an apparatus comprising: Figure 5 TRANS10D in Figure 5 MEM 10B, PROG 10C and DP 10A in the communication network) at least one of a first integrity key associated with the communication network or a second integrity key associated with the communication network; and then for selecting between using the first integrity key or the second integrity key based on at least one of a radio resource control message or a radio resource control state (such as Figure 5 TRANS10D in Figure 5 Components of MEM 10B, PROG 10C and DP 10A).

[0157] In an exemplary aspect of the invention according to the above paragraphs, wherein at least the means for determining and selecting comprises a non-transitory computer readable medium [such as Figure 5 MEM 10B], the non-transitory computer readable medium is encoded with a computer program [such as Figure 5 PROG 10C] in, the computer program can be executed by at least one processor [such as Figure 5 DP 10A] in is executed.

[0158] Figure 6B The diagram illustrates operations that may be performed by a network device, such as but not limited to: Figure 5 The network nodes NN 12 and / or NN 13 in Figure 6B As shown in step 650, an information context of a user equipment is determined for integrity protection of a radio resource control message, the information context of the user equipment comprising: a first integrity key and a second integrity key associated with the device. Figure 6B As shown in step 660, based on the radio resource control message, a selection is made between using the first integrity key or the second integrity key.

[0159] According to the example embodiment as described above, the first integrity key and the second integrity key are determined by a first distributed unit and a centralized unit associated with the apparatus in one of the following items: before or after indicating that a radio resource control configuration with the user equipment is to be released and the user equipment is to be scheduled to a radio resource control inactive state.

[0160] According to an example embodiment as described in the above paragraphs, wherein a second integrity key is selected for at least one radio resource control restoration request message, and the selected integrity key is used to generate an integrity token for at least the radio resource control restoration request message.

[0161] According to an example embodiment as described in the above paragraphs, wherein a second integrity key is selected for use with at least a radio resource control release message, and an integrity token is generated using the selected integrity key to verify the validity of the integrity token of the radio resource control release message received from the network.

[0162] According to an example embodiment as described in the above paragraph, wherein at least one of the determined first integrity key or the second integrity key is based on being released from a connected state.

[0163] According to an example embodiment as described in the above paragraphs, wherein at least one of the first integrity keys is generated by a centralized unit associated with the communication network, or the second integrity key is generated by a first distributed unit associated with the communication network.

[0164] According to an example embodiment as described in the above paragraphs, wherein generating the second integrity key is based on key material received from the network.

[0165] According to an example embodiment as described in the above paragraphs, wherein the key material is received when the user equipment is scheduled into a radio resource control inactive state.

[0166] According to an example embodiment as described in the above paragraphs, wherein key material is received together with a user equipment identifier to be used for the radio resource control inactive state.

[0167] According to an example embodiment as described in the above paragraphs, at least the first integrity key and the second integrity key are one of predetermined by the user equipment or derived by the user equipment.

[0168] According to an example embodiment as described in the above paragraph, wherein the key material comprises at least one of: an indication of an integrity protection algorithm, and an indication of an algorithm identifier.

[0169] According to an example embodiment as described in the above paragraphs, wherein the integrity token comprises resumeMAC-I.

[0170] According to an example embodiment as described in the above paragraphs, wherein the first integrity key is K RRCint The user equipment is applying integrity protection to all radio resource control messages except at least one of a radio resource control resumption request message or a radio resource control release message using the first integrity key.

[0171] According to an example embodiment as described in the above paragraph, wherein the selected integrity key comprises a second integrity key.

[0172] According to an example embodiment as described in the above paragraphs, wherein the key material comprises an integrity protection algorithm and an algorithm identifier, the integrity protection algorithm and the algorithm identifier can be fed by the user equipment to a key derivation algorithm to generate, by the user equipment, an integrity token for a radio resource control recovery request message.

[0173] According to an example embodiment as described in the above paragraphs, wherein the information context comprises a security context, the security context comprises a KRRCint_resume key for the user equipment.

[0174] According to the example embodiment as described in the above paragraphs, when the user device performs the radio resource control resumption procedure, the KRRCint_resume key is used to verify the validity of the MAC-I.

[0175] According to an example embodiment as described in the above paragraphs, wherein information comprising at least one of the first integrity key or the second integrity key is stored, and wherein the storing is based on a validity timer, wherein upon expiration of the validity timer the information context is discarded.

[0176] According to an example embodiment as described in the above paragraphs, wherein the validity timer is configured by the first distributed unit as T_INACTIVE_DU.

[0177] According to an example embodiment as described in the above paragraphs, wherein the user equipment has not yet determined that it has moved to an area of ​​the communication network controlled by the apparatus.

[0178] According to the example embodiment as described in the above paragraphs, it includes: receiving, by a second distributed unit of the apparatus, a user equipment context acquisition request and a radio resource control resumption request from a user equipment, wherein the radio resource control resumption request includes an indication of resumeMAC-I and an integrity token.

[0179] According to the example embodiment as described in the above paragraphs, a radio resource control resumption request including resumeMAC-I is sent to the centralized unit based on the second distributed unit not identifying the user equipment.

[0180] According to an example embodiment as described in the above paragraphs, wherein the received resumeMAC-I is verified using a stored key received from the centralized unit based on the second distributed unit identifying the user equipment.

[0181] According to an example embodiment as described in the above paragraphs, wherein the information context is delivered to the second distributed unit by the centralized unit in response to a request from the user equipment.

[0182] According to the example embodiments as described in the above paragraphs, the integrity token for at least the radio resource control resumption request message is generated using the selected integrity key.

[0183] A non-transitory computer readable medium (such as Figure 5 MEM 12B and / or MEM 13B) in the storage device stores program code (such as Figure 5 PROG 12C and / or PROG 13C in the processor), the program code is executed by at least one processor (such as Figure 5 DP 12A and / or DP 13A) in the processor are executed to perform at least the operations described in the above paragraphs.

[0184] According to an exemplary embodiment of the present invention as described above, there is an apparatus comprising: Figure 5 TRANS12D and / or TRANS13D in the embodiment; MEM 12B and / or MEM 13B, PROG 12C and / or PROG 13C, and DP 12A and / or DP 13A) is a component for determining an information context of a user equipment for integrity protection of a radio resource control message, the information context of the user equipment comprising: a first integrity key and a second integrity key associated with the device, and a selection between using the first integrity key or the second integrity key based on the radio resource control message (such as Figure 5 TRANS12D and / or TRANS13D; MEM 12B and / or MEM 13B, PROG 12C and / or PROG 13C, and DP12A and / or DP 13A).

[0185] In an exemplary aspect of the invention according to the above paragraphs, wherein the means for storing and selecting comprises at least a non-transitory computer readable medium [such as Figure 5 MEM 12B and / or MEM 13B] in the non-transitory computer readable medium is encoded with a computer program [such as Figure 5 PROG 12C and / or PROG 13C] in, the computer program is executed by at least one processor [such as Figure 5DP 12A and / or DP 13A] in can be executed.

[0186] In addition, according to an exemplary embodiment of the present invention, there is a circuit system for performing operations according to the exemplary embodiment of the present invention disclosed herein. The circuit system may include any type of circuit system, including: content encoding circuit system, content decoding circuit system, processing circuit system, image generation circuit system, data analysis circuit system, etc. In addition, the circuit system may include: discrete circuit system, application-specific integrated circuit system (ASIC), and / or field programmable gate array circuit system (FPGA), etc., and a processor specially configured by software to perform corresponding functions, or a dual-core processor with software and a corresponding digital signal processor, etc. In addition, the necessary inputs to the circuit system and the necessary outputs from the circuit system, the functions performed by the circuit system, and the interconnection of the circuit system with other components that may include other circuit systems (possibly via inputs and outputs) are also provided to perform the exemplary embodiments of the present invention as described herein.

[0187] According to an exemplary embodiment of the present invention as disclosed in this application, the provided “circuitry system” may include at least one or more or all of the following:

[0188] (a) hardware circuit implementation only (e.g., implementation only in analog and / or digital circuitry);

[0189] (b) a combination of hardware circuitry and software such as (where applicable):

[0190] (i) a combination of analog and / or digital hardware circuits and software / firmware; and

[0191] (ii) any portion of hardware processor(s) with software (including digital signal processor(s), software and memory(s) that work together to enable a device (such as a mobile phone or server) to perform various functions (such as, functions or operations according to example embodiments of the present invention as disclosed herein); and

[0192] (c) Hardware circuits and / or processor(s), such as microprocessor(s) or portions of microprocessor(s), require software (e.g., firmware) to operate, but the software may not be present when the software is not required for operation.

[0193] According to an example embodiment of the present invention, there is sufficient circuitry to perform at least the novel operations as disclosed in this application, and such "circuitry" as may be used herein refers to at least the following:

[0194] (a) hardware circuit implementation only (such as implementation only in analog and / or digital circuitry); and

[0195] (b) a combination of circuitry and software (and / or firmware), such as, as applicable: (i) a combination of processor(s) or (ii) portions of processor(s) / software (including digital signal processor(s), software and memory(s), which work together to enable a device (such as a mobile phone or server) to perform various functions; and

[0196] (c) Circuitry, such as microprocessor(s) or portion(s) of microprocessor(s), requires software or firmware in order to operate, even though the software or firmware is not physically present.

[0197] This definition of “circuitry” applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term “circuitry” would also cover an implementation of only a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and / or firmware. The term “circuitry” would also cover, for example, a baseband integrated circuit or an application processor integrated circuit for a mobile phone or a similar integrated circuit in a server, cellular network device, or other network device, if applicable to the particular claim element.

[0198] In general, various embodiments may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software, which may be executed by a controller, microprocessor, or other computing device, but the invention is not limited thereto. Although various aspects of the invention may be illustrated and described in block diagrams, flow charts, or using some other graphical representations, it is fully understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general hardware or controllers or other computing devices, or combinations thereof.

[0199] Embodiments of the present invention may be practiced in various components, such as integrated circuit modules. The design of integrated circuits is generally a highly automated process. Complex and powerful software tools are available to convert a logic level design into a semiconductor circuit design that is ready to be etched and formed on a semiconductor substrate.

[0200] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. All embodiments described in this detailed description are exemplary embodiments provided to enable persons skilled in the art to make or use the invention, rather than to limit the scope of the invention defined by the claims.

[0201] The foregoing description has provided by way of exemplary and non-limiting examples a complete and informative description of the best method and apparatus presently contemplated by the inventors for carrying out the invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. Nevertheless, all such and similar modifications of the teachings of the exemplary embodiments of this invention will still fall within the scope of the present invention.

[0202] It should be noted that the terms "connected," "coupled," or any variations thereof, refer to any direct or indirect connection or coupling between two or more elements, and may encompass the presence of one or more intermediate elements between two elements that are "connected" or "coupled" together. The coupling or connection between elements may be physical, logical, or a combination thereof. As used herein, two elements may be considered to be "connected" or "coupled" together by using one or more wires, cables, and / or printed electrical connections, as well as by using electromagnetic energy (such as electromagnetic having wavelengths in the radio frequency region, microwave region, and optical (both visible and invisible) region), as a few non-limiting and non-exhaustive examples.

[0203] Furthermore, some features of the preferred embodiments of the present invention may be used to advantage without the corresponding use of other features. Therefore, the foregoing description should be regarded as merely illustrative of the principles of the present invention, and not in limitation thereof.

Claims

1. A device comprising: at least one processor; as well as at least one non-transitory memory comprising computer program code, wherein the at least one non-transitory memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least: determining information including at least one of a first integrity key or a second integrity key associated with a communication network; as well as Based on at least one of a radio resource control message or a radio resource control state, a selection is made between using the first integrity key or the second integrity key.

2. The apparatus of claim 1 , wherein the at least one non-transitory memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to: The second integrity key is selected for use at least with a radio resource control restoration request message, and an integrity token for at least the radio resource control restoration request message is generated using the selected integrity key.

3. The apparatus of claim 1 , wherein the at least one non-volatile memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to: select the second integrity key to be used at least for a radio resource control release message, and use the selected integrity key to generate an integrity token to verify validity of the integrity token of the radio resource control release message received from the network.

4. The apparatus of claim 1 , wherein the at least one of the determined first integrity key or the second integrity key is based on being released from a connected state.

5. The apparatus of claim 1, wherein the at least one of the first integrity key or the second integrity key is generated by at least one of a first distributed unit or a centralized unit associated with the communication network.

6. The apparatus of claim 1, wherein generating the second integrity key is based on key material received from the network.

7. The apparatus of claim 6, wherein the key material is received after the user equipment is scheduled into the radio resource control inactive state.

8. The apparatus of claim 6, wherein the key material is received together with a user equipment identifier to be used in the radio resource control inactive state.

9. The apparatus of claim 1, wherein the at least the first integrity key and the second integrity key are one of: predetermined by the user equipment or derived by the user equipment.

10. The apparatus of claim 6, wherein the key material comprises at least one of: an indication of an integrity protection algorithm, and an indication of an algorithm identifier.

11. The apparatus of claim 2, wherein the integrity token comprises a resu meMAC-I.

12. The apparatus of claim 1, wherein the first integrity key is K RRCint A key is provided, and the user equipment is applying integrity protection on all radio resource control messages except at least one of a radio resource control resumption request message or a radio resource control release message using the first integrity key.

13. The apparatus of claim 1, wherein the selected integrity key comprises the second integrity key.

14. The apparatus of claim 1 , wherein the key material comprises an integrity protection algorithm and an algorithm identifier, the integrity protection algorithm and algorithm identifier being capable of being fed by the user equipment to a key derivation algorithm to generate, by the user equipment, the integrity token for the radio resource control recovery request message.

15. The apparatus of claim 1, wherein the information comprises a security context comprising a KRRCint_resume key for the user equipment.

16. The apparatus of claim 15, wherein the KRRCint_resume key is used to verify the MAC-I validity when the user equipment receives a radio resource control release message from the network.

17. The apparatus of claim 1 , wherein the at least one non-volatile memory and the computer program code are configured to, with the at least one processor, cause the apparatus to: store the information comprising the at least one of the first integrity key or the second integrity key, and wherein the storing is based on a validity timer, wherein upon expiration of the validity timer, the information context is discarded.

18. An apparatus comprising: means for determining at least one of a first integrity key or a second integrity key associated with a communication network; as well as Means for selecting between using the first integrity key or the second integrity key based on at least one of a radio resource control message or a radio resource control state.

19. A method comprising: determining at least one of a first integrity key or a second integrity key associated with the communication network; as well as Based on at least one of a radio resource control message or a radio resource control state, a selection is made between using the first integrity key or the second integrity key.

20. The method of claim 19, wherein the at least one non-transitory memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least: The second integrity key is selected for use at least with a radio resource control restoration request message, and an integrity token for at least the radio resource control restoration request message is generated using the selected integrity key.

21. The method according to claim 19, comprising: The second integrity key is selected for use at least with a radio resource control release message, and an integrity token is generated using the selected integrity key to verify validity of the integrity token of the radio resource control release message received from the network.

22. The method of claim 19, wherein the at least one of the determined first integrity key or the second integrity key is based on being released from a connected state.

23. The method of claim 19, wherein the at least one of the first integrity key or the second integrity key is generated by at least one of a first distributed unit or a centralized unit associated with the communication network.

24. The method of claim 19, wherein generating the second integrity key is based on key material received from the network.

25. The method of claim 24, wherein the key material is received after the user equipment is scheduled into a radio resource control inactive state.

26. The method of claim 24, wherein the key material is received with a user equipment identifier to be used in the radio resource control inactive state.

27. The method of claim 19, wherein the at least one of the first integrity key or the second integrity key is one of: predetermined by the user equipment or derived by the user equipment.

28. The method of claim 24, wherein the key material comprises at least one of: an indication of an integrity protection algorithm, and an indication of an algorithm identifier.

29. The method of claim 21, wherein the integrity token comprises a resumeMAC-I.

30. The method of claim 19, wherein the first integrity key is K RRCint A key is provided, and the user equipment is applying integrity protection on all radio resource control messages except at least one of a radio resource control resumption request message or a radio resource control release message using the first integrity key.

31. The method of claim 19, wherein the selected integrity key comprises the second integrity key.

32. The method of claim 24, wherein the key material comprises an integrity protection algorithm and an algorithm identifier, which can be fed by the user equipment to a key derivation algorithm to generate the integrity token for the radio resource control recovery request message by the user equipment.

33. The method of claim 19, wherein the information comprises a security context including a KRRCint_resume key for the user equipment.

34. The method of claim 33, wherein the KRRCint_resume key is used to verify the MAC-I validity when the user equipment receives a radio resource control release message from the network.

35. The method of claim 19, comprising: An integrity token is generated at least for a radio resource control resumption request message using the selected integrity key.

36. The method of claim 19, comprising: The at least one of the first integrity key or the second integrity key is stored, wherein the storing is based on a validity timer, wherein upon expiration of the validity timer, the information context is discarded.

37. An apparatus comprising: at least one processor; as well as at least one non-transitory memory comprising computer program code, wherein the at least one non-transitory memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least: determining an information context of a user equipment for integrity protection of a radio resource control message, the information context of the user equipment comprising: a first integrity key and a second integrity key associated with the apparatus, and Based on the radio resource control message, a selection is made between using the first integrity key or the second integrity key.

38. The apparatus of claim 37, wherein the information context including the first integrity key and the second integrity key is determined one of before or after: identifying that a radio resource control configuration with the user equipment is to be released and the user equipment is to be scheduled to a radio resource control inactive state.

39. The apparatus of claim 37, wherein the at least one of the first integrity key or the second integrity key is generated by at least one of a first distributed unit or a centralized unit associated with the communication network.

40. The apparatus of claim 37, wherein key material is generated by the first distributed unit when the user equipment is scheduled into a radio resource control inactive state.

41. An apparatus according to claim 40, wherein the key material is received together with a user device identifier to be used in an inactive state.

42. The apparatus of claim 40, wherein the key material comprises at least one of: an indication of an integrity protection algorithm, and an indication of an algorithm identifier.

43. The apparatus of claim 40, wherein the key material is sent to the user device.

44. The apparatus of claim 37, wherein the selected integrity key is used to generate an integrity token for at least a radio resource control resume request message, and wherein the integrity token comprises resumeMAC-I.

45. The apparatus of claim 37, wherein the selected integrity key comprises the second integrity key.

46. ​​An apparatus according to claim 37, wherein the key material includes an integrity protection algorithm and an algorithm identifier, which can be fed by the user equipment to a key derivation algorithm to generate the integrity token for the radio resource control recovery request message by the user equipment.

47. The apparatus of claim 37, wherein the information context comprises a security context, the security context comprising a KRRCint_resume key for the user equipment.

48. The apparatus of claim 47, wherein the at least one non-volatile memory comprising the computer program code is configured to, together with the at least one processor, cause the apparatus to: generate the integrity token for integrity protection of a radio resource control release message based on the KRRCint_resume key.

49. The apparatus of claim 37, wherein the at least one non-transitory memory comprising the computer program code is configured to, with the at least one processor, cause the apparatus to: store at least one of the first integrity key or the second integrity key generated by the first distributed unit, wherein the storing is based on a validity timer, wherein upon expiration of the validity timer, the information context is discarded.

50. The apparatus of claim 37, wherein the validity timer is configured by the first distributed unit as T_INACTIVE_DU.

51. The apparatus of claim 43, wherein based on the fact that the second distributed unit does not identify the user equipment, the at least one non-volatile memory comprising the computer program code is configured to, together with the at least one processor, cause the apparatus to: send the radio resource control resumption request including the resumeMAC-I to the centralized unit.

52. An apparatus according to claim 44, wherein based on the identification of the user equipment by the second distributed unit, the at least one non-volatile memory comprising the computer program code is configured to, together with the at least one processor, enable the apparatus to: use the stored key received from the centralized unit to verify the received resumeM AC-I.

53. An apparatus according to claim 44, wherein the at least one non-volatile memory including the computer program code is configured to, together with the at least one processor, enable the apparatus to: in response to the radio resource control recovery request message from the user equipment, utilize the centralized unit to deliver the information context to the second distributed unit.

54. An apparatus comprising: means for determining an information context of a user equipment for integrity protection of a radio resource control message, the information context of the user equipment comprising: a first integrity key and a second integrity key associated with the apparatus, and Means for selecting between using the first integrity key or the second integrity key based on the radio resource control message.

55. A method comprising: determining an information context of a user equipment for integrity protection of a radio resource control message, the information context of the user equipment comprising: a first integrity key and a second integrity key associated with the apparatus, and Based on the radio resource control message, a selection is made between using the first integrity key or the second integrity key.

56. The method of claim 55, wherein the first integrity key and the second integrity key are determined one of before or after identifying that a radio resource control configuration with the user equipment is to be released and the user equipment is to be scheduled to a radio resource control inactive state.

57. The method of claim 55, wherein the at least one of the first integrity key or the second integrity key is generated by at least one of a first distributed unit or a centralized unit associated with the communication network.

58. The method of claim 55, wherein key material is received by the first distributed unit when the user equipment is scheduled into a radio resource control inactive state.

59. The method of claim 55, wherein the key material is received with a user device identifier to be used in an inactive state.

60. The method of claim 58, wherein the key material comprises at least one of: an indication of an integrity protection algorithm, and an indication of an algorithm identifier.

61. The method of claim 59, wherein the key material is sent to the user device.

62. The method of claim 55, wherein the selected integrity key is used to generate an integrity token for at least a radio resource control resumption request message.

63. The method of claim 62, wherein the integrity token comprises a resumeMAC-I.

64. The method of claim 55, wherein the selected integrity key comprises the second integrity key.

65. A method according to claim 58, wherein the key material includes an integrity protection algorithm and an algorithm identifier, which can be fed by the user equipment to a key derivation algorithm to generate the integrity token for the radio resource control recovery request message by the user equipment.

66. The method of claim 55, wherein the information comprises a security context including a KRRCint_resume key for the user equipment.

67. The method of claim 66, wherein the KRRCint_resume key is used to verify the resumeMAC-I validity when the user equipment performs a radio resource control resumption procedure.

68. The method of claim 66, comprising: Based on the KRRCint_resume key, an integrity token for integrity protection of the radio resource control release message is generated.

69. The method of claim 55, wherein the determining is based on a validity timer, wherein upon expiration of the validity timer, the information context is discarded.

70. The method of claim 69, wherein the validity timer is configured by the first distributed unit as T_INACTIVE_DU.

71. The method of claim 55, comprising: storing at least one of the first integrity key or the second integrity key generated by the first distributed unit, wherein the storing is based on the validity timer, wherein upon expiration of the validity timer, the information context is discarded.

72. The method of claim 55, wherein based on the second distributed unit not identifying the user equipment, the method comprises: The radio resource control resumption request including resu meMAC-I is sent to the central unit.

73. The method of claim 55, wherein based on identifying the user equipment by the second distributed unit, the method comprises: The received resumeMAC-I is verified using the stored key received from the centralized unit.

74. The method of claim 55, comprising: In response to the request from the user equipment, the information context is delivered to the second distributed unit using the centralized unit.

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