Method and apparatus for handling non-integrity protected rejection messages in non-public networks

Abstract

Methods and apparatus, including computer program products, are provided for handling non-integrity protected rejection messages in a non-public network. In some example embodiments, an apparatus may be provided that includes at least one processor and at least one memory including computer program code, the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least: receive a reject message from a network function in a standalone non-public network (SNPN), where information in the reject message indicates that the apparatus is not allowed to access the SNPN by subscription; and adding an identification of the SNPN to a forbidden SNPN list associated with an access via which the device sends a request and subsequently receives the rejection message.

Description

[0001] This application is a divisional application of the invention patent application with international application number PCT / FI2020 / 050503, international application date July 24, 2020, entering the Chinese national stage on April 12, 2022, Chinese national application number 202080071657.0, and invention name “Method and device for processing rejection messages that are not integrity protected in non-public networks”. Technical Field

[0002] The subject matter described herein relates to wireless telecommunications. Background Art

[0003] Telecommunication networks such as the fifth generation mobile network (5G network) are expected to be the next major stage in mobile telecommunication standards and bring many improvements to the mobile network user experience. For example, 5G networks should provide new technical solutions that allow for greater throughput, lower latency, higher reliability, increased connectivity, and greater mobility range.

[0004] In addition to these improvements in performance, 5G networks are also expected to expand the flexibility of network usage and allow a wider range of use cases and business models to be offered to users.

[0005] However, as 5G systems support an increasing number of devices and services, including applications with a wide range of use cases and varying demands in terms of bandwidth, latency and reliability requirements, user devices operating on and communicating through cellular systems are increasingly susceptible to malicious communications such as Denial of Service (DoS) attacks. Summary of the invention

[0006] Methods, apparatus, and computer program products are provided for handling non-integrity protected rejection messages in a non-public network.

[0007] In some example embodiments, an apparatus may be provided, comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus to at least: receive a rejection message from a network function in a standalone non-public network (SNPN), wherein information in the rejection message indicates that the apparatus is not allowed to access the SNPN through subscription; and add an identifier of the SNPN to a list of prohibited SNPNs, wherein the apparatus sends a request for access through subscription for the prohibited SNPN and subsequently receives the rejection message. In some embodiments, the information in the rejection message includes a fifth generation mobility management (5GMM) cause value #72, #74, or #75. In some embodiments, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to at least: set a fifth generation system (5GS) update state to 5U3 ROAMING NOTALLOWED; store the 5GS update state; and delete each of a 5G globally unique temporary identity (5G-GUTI), a last visited registration TAI, a TAI list, and a key set identifier (ngKSI). In some embodiments, at least one memory and computer program code are further configured to, together with at least one processor, cause the device to at least: cause the device to enter a 5GMM-DEREGISTERED state or a 5GMM-DEREGISTERED.PLMN-SEARCH state; and cause the device to perform SNPN selection. In some embodiments, at least one memory and computer program code are further configured to, together with at least one processor, cause the device to at least: determine whether the non-access stratum (NAS) has successfully performed an integrity check on the rejection message; and if the NAS has successfully performed an integrity check on the rejection message, the SNPN-specific attempt counter for non-third generation partnership project (non-3GPP) access for SNPN is set to a user equipment-specific maximum value. In some embodiments, the banned SNPN list is a permanently banned SNPN list. In some embodiments, the banned SNPN list is a temporarily banned SNPN list. In some embodiments, the banned SNPN list is a permanently banned SNPN list for non-3GPP access. In some embodiments, the banned SNPN list is a temporarily banned SNPN list for non-3GPP access.

[0008] In other example embodiments, a method, such as a computer-implemented method, may be provided, which may be implemented, for example, using an apparatus such as described herein. In some embodiments, the method may include: receiving a rejection message from a network function in a standalone non-public network (SNPN), wherein information in the rejection message indicates that the apparatus is not allowed to access the network through subscription; and adding an identification of the SNPN to a list of prohibited SNPNs, wherein the apparatus sends a request for access through subscription for the prohibited SNPN and subsequently receives the rejection message. In some embodiments, the information in the rejection message includes a 5GMM cause value #72, #74, or #75. In some embodiments, the method further includes: setting the 5GS update state to 5U3 ROAMING NOT ALLOWED; storing the 5GS update state; and deleting each of the 5G-GUTI, the last visited registered TAI, the TAI list, and the ngKSI. In some embodiments, the method further includes: causing the apparatus to enter a 5GMM-DEREGISTERED state or a 5GMM-DEREGISTERED.PLMN-SEARCH state; and causing the apparatus to perform SNPN selection. In some embodiments, the method further comprises: determining whether NAS has successfully performed an integrity check on the rejection message; and if NAS has successfully performed an integrity check on the rejection message, setting the SNPN-specific attempt counter for non-3GPP access for the SNPN to a user equipment-implemented specific maximum value. In some embodiments, the banned SNPN list is a permanently banned SNPN list. In some embodiments, the banned SNPN list is a temporarily banned SNPN list. In some embodiments, the banned SNPN list is a permanently banned SNPN list for non-3GPP access. In some embodiments, the banned SNPN list is a temporarily banned SNPN list for non-3GPP access.

[0009] In other example embodiments, an apparatus may be provided, such as an apparatus including at least one processor and at least one memory storing computer program code, which may be configured to implement a method such as described herein. In some embodiments, the apparatus may include: a component for receiving a rejection message from a network function in a standalone non-public network (SNPN), wherein the information in the rejection message indicates that the apparatus is not allowed to access the SNPN through subscription. In some embodiments, the apparatus may include a component for adding an identifier of the SNPN to a list of prohibited SNPNs, wherein the apparatus sends a request for access through subscription for the prohibited SNPN and subsequently receives the rejection message. In some embodiments, the information in the rejection message includes a 5GMM cause value #72, #74, or #75. In some embodiments, the apparatus may further include: a component for setting the 5GS update status to 5U3 ROAMING NOT ALLOWED; a component for storing the 5GS update status; and a component for deleting each of the 5G-GUTI, the last visited registered TAI, the TAI list, and the ngKSI. In some embodiments, the device may further include: a component for causing the device to enter a 5GMM-DEREGISTERED state or a 5GMM-DEREGISTERED.PLMN-SEARCH state; and a component for causing the device to perform SNPN selection. In some embodiments, the device may further include: a component for determining whether NAS has successfully performed an integrity check on the rejection message; and a component for setting the SNPN-specific attempt counter for non-3GPP access for SNPN to a specific maximum value achieved by the user equipment if NAS has successfully performed an integrity check on the rejection message. In some embodiments, the banned SNPN list is a permanently banned SNPN list. In some embodiments, the banned SNPN list is a temporarily banned SNPN list. In some embodiments, the banned SNPN list is a permanently banned SNPN list for non-3GPP access. In some embodiments, the banned SNPN list is a temporarily banned SNPN list for non-3GPP access.

[0010] In other example embodiments, a computer program product may be provided, such as a non-transitory computer-readable medium including program code, which when executed results in operations including: receiving a rejection message from a network function in a standalone non-public network (SNPN), wherein the information in the rejection message indicates that the device is not allowed to access the SNPN through subscription; and adding an identification of the SNPN to a list of prohibited SNPNs, wherein the device sends a request for access through subscription for the prohibited SNPN and subsequently receives the rejection message. In some embodiments, the information in the rejection message includes a 5GMM cause value #72, #74, or #75. In some embodiments, the program code results in further operations, which further operations include: setting the 5GS update status to 5U3 ROAMING NOT ALLOWED; storing the 5GS update status; and deleting each of the 5G-GUTI, the last visited registered TAI, the TAI list, and the ngKSI. In some embodiments, the program code causes further operations, which include: causing the device to enter a 5GMM-DEREGISTERED state or a 5GMM-DEREGISTERED.PLMN-SEARCH state; and causing the device to perform SNPN selection. In some embodiments, the program code causes further operations, which include: determining whether NAS has successfully performed an integrity check on the rejection message; and if NAS has successfully performed an integrity check on the rejection message, setting the SNPN-specific attempt counter for non-3GPP access for SNPN to a user equipment-implemented specific maximum value. In some embodiments, the banned SNPN list is a permanently banned SNPN list. In some embodiments, the banned SNPN list is a temporarily banned SNPN list. In some embodiments, the banned SNPN list is a permanently banned SNPN list for non-3GPP access. In some embodiments, the banned SNPN list is a temporarily banned SNPN list for non-3GPP access.

[0011] According to yet another embodiment, a device is provided, comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the device to at least: store a user data list, wherein each entry in the user data list comprises user data for accessing a standalone non-public network (SNPN); maintain one or more prohibited SNPN lists and one or more SNPN-specific attempt counters; and in the case where an entry in the user data list is reconfigured or removed, based on the one or more SNPN-specific attempt counters, determine whether the identification of the SNPN associated with the reconfigured or removed entry should be removed from the one or more prohibited SNPN lists. In some embodiments, the one or more prohibited SNPN lists comprise a permanently prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists comprise a temporarily prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists comprise a permanently prohibited SNPN list for non-3GPP access. In some embodiments, the one or more prohibited SNPN lists comprise a temporarily prohibited SNPN list for non-3GPP access. In some embodiments, the one or more SNPN-specific attempt counters comprise SNPN-specific attempt counters for 3GPP access. In some embodiments, the one or more SNPN-specific attempt counters include a SNPN-specific attempt counter for non-3GPP access.

[0012] According to yet another embodiment, a method is provided, the method comprising: storing a user data list, wherein each entry in the user data list comprises user data for accessing a standalone non-public network (SNPN); maintaining one or more prohibited SNPN lists and one or more SNPN-specific attempt counters; and determining whether the identification of the SNPN associated with the reconfigured or removed entry should be removed from the one or more prohibited SNPN lists based on the one or more SNPN-specific attempt counters in the event that an entry in the user data list is reconfigured or removed. In some embodiments, the one or more prohibited SNPN lists comprise a permanently prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists comprise a temporarily prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists comprise a permanently prohibited SNPN list for non-3GPP access. In some embodiments, the one or more prohibited SNPN lists comprise a temporarily prohibited SNPN list for non-3GPP access. In some embodiments, the one or more SNPN-specific attempt counters comprise an SNPN-specific attempt counter for 3GPP access. In some embodiments, the one or more SNPN-specific attempt counters comprise an SNPN-specific attempt counter for non-3GPP access.

[0013] According to another embodiment, a device is provided, such as a device including one or more processors and one or more memories storing computer program code. Such a device may be configured to perform any of the methods described herein, such as by using one or more processors to execute computer-implemented instructions stored on one or more memories. In some embodiments, the device may include: a component for storing a user data list, wherein each entry in the user data list includes user data for accessing a standalone non-public network (SNPN); a component for maintaining one or more prohibited SNPN lists and one or more SNPN-specific attempt counters; and a component for determining whether the identification of the SNPN associated with the reconfigured or removed entry should be removed from the one or more prohibited SNPN lists based on the one or more SNPN-specific attempt counters when the entry of the user data list is reconfigured or removed. In some embodiments, the one or more prohibited SNPN lists include a permanently prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists include a temporarily prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists include a permanently prohibited SNPN list for non-3GPP access. In some embodiments, the one or more prohibited SNPN lists include a temporarily prohibited SNPN list for non-3GPP access. In some embodiments, the one or more SNPN-specific attempt counters include a SNPN-specific attempt counter for 3GPP access. In some embodiments, the one or more SNPN-specific attempt counters include a SNPN-specific attempt counter for non-3GPP access.

[0014] In another example embodiment, a computer program product including a non-transitory computer-readable medium is provided, the non-transitory computer-readable medium including program code, which when executed causes operations, the operations including: storing a user data list, wherein each entry in the user data list includes user data for accessing a standalone non-public network (SNPN); maintaining one or more prohibited SNPN lists and one or more SNPN-specific attempt counters; and determining whether the identification of the SNPN associated with the reconfigured or removed entry should be removed from the one or more prohibited SNPN lists based on the one or more SNPN-specific attempt counters in the event that an entry in the user data list is reconfigured or removed. In some embodiments, the one or more prohibited SNPN lists include a permanent prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists include a temporary prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists include a permanent prohibited SNPN list for non-3GPP access. In some embodiments, the one or more prohibited SNPN lists include a temporary prohibited SNPN list for non-3GPP access. In some embodiments, the one or more SNPN-specific attempt counters include SNPN-specific attempt counters for 3GPP access. In some embodiments, the one or more SNPN-specific attempt counters include a SNPN-specific attempt counter for non-3GPP access.

[0015] According to another embodiment, a device is provided, the device including at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the device to at least: store a user data list, wherein each of a plurality of entries in the user data list includes user data for accessing a standalone non-public network (SNPN); receive a rejection message that is not integrity protected from a network function in the SNPN, wherein the information in the rejection message indicates that the entry for accessing the SNPN is invalid; upon receiving the rejection message, determine whether the entry for accessing the SNPN is invalid for the access via which the device sends a request message and / or receives the rejection message, and start T3247; and maintain one or more counters for the SNPN, wherein the one or more counters are used to determine whether the entry for accessing the SNPN should be set to valid when T3247 expires. In some embodiments, the information in the rejection message includes a 5GMM cause value #3 or #6. In some embodiments, the information in the rejection message includes an AUTHENITCATION REJECT message. In some embodiments, the rejection message is a REGISTRATION REJECT message or a SERVICE REJECT message. In some embodiments, the one or more counters include: a counter for events in which an entry for the current SNPN is considered invalid for 3GPP access; and a counter for events in which an entry for the current SNPN is considered invalid for non-3GPP access.

[0016] In yet another embodiment, a method is provided, the method comprising: storing a user data list, wherein each of a plurality of entries in the user data list comprises user data for accessing a standalone non-public network (SNPN); receiving a rejection message that is not integrity protected from a network function in the SNPN, wherein information in the rejection message indicates that the entry for accessing the SNPN is invalid; upon receiving the rejection message, determining whether the entry for accessing the SNPN is invalid for the access via which the device sends a request message and / or receives the rejection message, and starting T3247; and maintaining one or more counters for the SNPN, wherein the one or more counters are used to determine whether the entry for accessing the SNPN should be set to valid when T3247 expires. In some embodiments, the information in the rejection message comprises a 5GMM cause value #3 or #6. In some embodiments, the information in the rejection message comprises an AUTHENITCATION REJECT message. In some embodiments, the rejection message is a REGISTRATION REJECT message or a SERVICE REJECT message. In some embodiments, the one or more counters include: a counter for events where an entry for a current SNPN is considered invalid for 3GPP access; and a counter for events where an entry for a current SNPN is considered invalid for non-3GPP access.

[0017] According to another embodiment, a device is provided, such as a device including one or more processors and one or more memories storing computer program code. Such a device may be configured to perform any of the methods described herein, such as by using one or more processors to execute computer-implemented instructions stored on one or more memories. In some embodiments, the device may include: a component for storing a user data list, wherein each of a plurality of entries in the user data list includes user data for accessing a standalone non-public network (SNPN); a component for receiving a rejection message that is not integrity protected from a network function in the SNPN, wherein the information in the rejection message indicates that the entry for accessing the SNPN is invalid; a component for determining, upon receiving the rejection message, whether the entry for accessing the SNPN is invalid for the access via which the device sends a request message and / or receives the rejection message, and starting T3247; and a component for maintaining one or more counters for the SNPN, wherein the one or more counters are used to determine whether the entry for accessing the SNPN should be set to valid when T3247 expires. In some embodiments, the information in the rejection message includes a 5GMM cause value #3 or #6. In some embodiments, the information in the rejection message includes an AUTHENITCATION REJECT message. In some embodiments, the rejection message is a REGISTRATION REJECT message or a SERVICE REJECT message. In some embodiments, the one or more counters include: a counter for events in which an entry for the current SNPN is considered invalid for 3GPP access; and a counter for events in which an entry for the current SNPN is considered invalid for non-3GPP access.

[0018] According to another embodiment, a computer program product including a non-transitory computer-readable medium is provided, the non-transitory computer-readable medium including program code, which when executed causes operations, the operations including: storing a user data list, wherein each of a plurality of entries in the user data list includes user data for accessing a standalone non-public network (SNPN); receiving a rejection message that is not integrity protected from a network function in the SNPN, wherein the information in the rejection message indicates that the entry for accessing the SNPN is invalid; upon receiving the rejection message, determining whether the entry for accessing the SNPN is invalid for the access via which the device sends a request message and / or receives the rejection message, and starting T3247; and maintaining one or more counters for the SNPN, wherein the one or more counters are used to determine whether the entry for accessing the SNPN should be set to valid when T3247 expires. In some embodiments, the information in the rejection message includes a 5GMM cause value #3 or #6. In some embodiments, the information in the rejection message includes an AUTHENITCATION REJECT message. In some embodiments, the rejection message is a REGISTRATION REJECT message or a SERVICE REJECT message.In some embodiments, the one or more counters include: a counter for events where an entry for the current SNPN is considered invalid for 3GPP access; and a counter for events where an entry for the current SNPN is considered invalid for non-3GPP access.

[0019] According to another example embodiment, an apparatus is provided, the apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus to at least: receive a rejection message from a network function in a standalone non-public network (SNPN); start one or more timers, the one or more timers being configured to monitor the time elapsed since the rejection message was received; randomly determine a duration value within a predetermined range between a minimum value and a maximum value, the minimum value corresponding to a minimum safe duration for sending a subsequent registration request to the network function; via the one or more timers, determine whether the time elapsed since the rejection message was received corresponds to the randomly selected duration value; and if it is determined that the elapsed time corresponds to the randomly selected duration value, send the subsequent registration request to the network entity. In some embodiments, the registration rejection message includes a reason code indicating the reason why the network entity cannot register the apparatus. In some embodiments, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to at least: determine whether the registration rejection message is an integrity protected message based at least on the reason code. In some embodiments, at least one memory and computer program code are further configured to, with at least one processor, cause the apparatus to at least: immediately send a subsequent registration request to a network entity if the registration rejection message is determined to be an integrity protected message. In some embodiments, at least one memory and computer program code are further configured to, with at least one processor, cause the apparatus to at least: send an initial registration request to a network entity, the initial registration request comprising at least identification information for a user device. In some embodiments, one or more counters are associated with entries of a user data list maintained by the apparatus, the one or more counters comprising: a first counter associated with an entry of the user data list for a non-dedicated network considered for a network access event; and a second counter associated with an entry of the user data list for a dedicated network considered for a network access event. In some embodiments, the user data list is a temporary or permanent banned network list, wherein at least one memory and computer program code are further configured to, with at least one processor, cause the apparatus to at least: remove the entry of the user data list for a dedicated network from the temporary or permanent banned network list if the value of the second counter is greater than zero but less than a randomly selected duration value upon expiration of the second counter.

[0020] According to yet another embodiment, a method is provided, the method comprising: receiving a registration rejection message from a network entity in response to sending an initial registration request; starting one or more timers, the one or more timers being configured to monitor the time elapsed since the registration rejection message was received; randomly determining a duration value within a predetermined range between a minimum value and a maximum value, the minimum value corresponding to a minimum safe duration for sending a subsequent registration request to the network entity; determining, via the one or more timers, whether the time elapsed since the registration rejection message was received corresponds to the randomly selected duration value; and sending the subsequent registration request to the network entity if it is determined that the elapsed time corresponds to the randomly selected duration value. In some embodiments, the registration rejection message includes a reason code indicating why the network entity cannot register the device. In some embodiments, the method further comprises: determining, based at least on the reason code, whether the registration rejection message is an integrity protected message. In some embodiments, the method further comprises: immediately sending a subsequent registration request to the network entity if the registration rejection message is determined to be an integrity protected message. In some embodiments, the method further comprises: sending the initial registration request to the network entity, the initial registration request including at least identification information for the user equipment. In some embodiments, one or more counters are associated with an entry of a user data list maintained by the device, the one or more counters comprising: a first counter associated with an entry of the user data list for a non-dedicated network being considered for a network access event; and a second counter associated with an entry of the user data list for a dedicated network being considered for a network access event. In some embodiments, the user data list is a temporary or permanent banned network list, the method further comprising: removing the entry of the user data list for the dedicated network from the temporary or permanent banned network list if the value of the second counter is greater than zero but less than a randomly selected duration value upon expiration of the second counter.

[0021] According to another embodiment, an apparatus is provided, such as an apparatus including one or more processors and one or more memories storing computer program code. Such an apparatus may be configured to perform any of the methods described herein, such as by using one or more processors to execute computer-implemented instructions stored on one or more memories. In some embodiments, the apparatus may include: a component for receiving a registration rejection message from a network entity in response to sending an initial registration request; a component for starting one or more timers, wherein the one or more timers are configured to monitor the time elapsed since the registration rejection message was received; a component for randomly determining a duration value within a predetermined range between a minimum value and a maximum value, wherein the minimum value corresponds to a minimum safe duration for sending subsequent registration requests to the network entity; a component for determining, based on the one or more timers, whether the time elapsed since the registration rejection message was received corresponds to a randomly selected duration value; and a component for sending the subsequent registration request to the network entity if it is determined that the elapsed time corresponds to the randomly selected duration value. In some embodiments, the registration rejection message includes a reason code indicating the reason why the network entity cannot register the device. In some embodiments, the apparatus further includes: a component for determining whether the registration rejection message is an integrity protected message based at least on the reason code. In some embodiments, the apparatus further comprises: a component for immediately sending a subsequent registration request to the network entity if the registration rejection message is determined to be an integrity protected message. In some embodiments, the apparatus further comprises: a component for sending an initial registration request to the network entity, wherein the initial registration request comprises at least identification information for the user equipment. In some embodiments, one or more counters are associated with entries of a user data list maintained by the apparatus, the one or more counters comprising: a first counter associated with an entry of the user data list for a non-dedicated network considered for a network access event; and a second counter associated with an entry of the user data list for a dedicated network considered for a network access event. In some embodiments, the user data list is a temporary or permanent banned network list, and the apparatus further comprises: a component for removing the entry of the user data list for the dedicated network from the temporary or permanent banned network list if the value of the second counter is greater than zero but less than a randomly selected duration value upon expiration of the second counter.

[0022] According to yet another embodiment, a computer program product is provided that includes a non-transitory computer-readable medium that includes program code that, when executed, results in operations that include: receiving a registration rejection message from a network entity in response to sending an initial registration request; starting one or more timers configured to monitor the time that has passed since the registration rejection message was received; randomly determining a duration value within a predetermined range between a minimum value and a maximum value, the minimum value corresponding to a minimum safe duration for sending a subsequent registration request to the network entity; based on the one or more timers, determining whether the time that has passed since the registration rejection message was received corresponds to the randomly selected duration value; and if it is determined that the time that has passed corresponds to the randomly selected duration value, sending the subsequent registration request to the network entity. In some embodiments, the registration rejection message includes a reason code indicating why the network entity cannot register the device. In some embodiments, the program code results in further operations that include: determining, based at least on the reason code, whether the registration rejection message is an integrity-protected message. In some embodiments, the program code results in further operations that include: if the registration rejection message is determined to be an integrity-protected message, immediately sending a subsequent registration request to the network entity. In some embodiments, the program code causes further operations, the further operations comprising: sending an initial registration request to a network entity, the initial registration request comprising at least identification information for the user equipment. In some embodiments, one or more counters are associated with entries of a user data list maintained by the apparatus, the one or more counters comprising: a first counter associated with an entry of the user data list for a non-dedicated network being considered for a network access event; and a second counter associated with an entry of the user data list for a dedicated network being considered for a network access event. In some embodiments, the user data list is a list of temporarily or permanently banned networks, the program code causes further operations, the further operations comprising: removing the entry of the user data list for the dedicated network from the list of temporarily or permanently banned networks if the value of the second counter is greater than zero but less than a randomly selected duration value upon expiration of the second counter.

[0023] The above aspects and features can be implemented in systems, devices, methods and / or products according to the desired configuration. The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the following description. The features and advantages of the subject matter described herein will become apparent from the description and drawings and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In the attached picture:

[0025] Figure 1 depicts an example of a portion of a 5G wireless network according to some example embodiments;

[0026] Figure 2 depicts an example of an apparatus according to some example embodiments;

[0027] Figure 3 depicts an example of a process flow for a UE requesting registration with a network according to some example embodiments;

[0028] Figure 4 Depicting an example of a process flow for a UE to request provision of a service from a network according to some example embodiments;

[0029] Figure 5 depicts an example of a method for handling a non-integrity protected rejection message in a non-public network according to some example embodiments;

[0030] Figure 6 depicts another example of a method for handling a non-integrity protected rejection message in a non-public network according to some example embodiments;

[0031] Figure 7 depicts yet another example of a method for handling a non-integrity protected rejection message in a non-public network in accordance with some example embodiments;

[0032] Figure 8 depicts yet another example of a method for handling a non-integrity protected rejection message in a non-public network in accordance with some example embodiments;

[0033] Fig. 9 Another example of a method for handling non-integrity protected rejection messages in a non-public network is depicted in accordance with some example embodiments.

[0034] The same reference numbers are used to refer to the same or similar items in the drawings. DETAILED DESCRIPTION

[0035] In many cellular systems and telecommunication networks such as the fifth generation (5G) network, a user equipment (UE) may be configured to access a public land mobile network (PLMN), a standalone non-public network (SNPN), etc., through interaction, wherein the UE requests registration of the UE to the network, the network registers or rejects the UE, the network sends a registration message or a rejection message back to the UE, and if the UE receives the registration message, the UE performs a process for connecting to the network and authenticating the network. However, often and for various reasons, the network will send a rejection message to the UE, indicating that the network cannot register the UE for the network.

[0036] One of the key issues to be addressed by next generation telecommunication systems (e.g., 5G networks) is how to provide a robust method to prevent DoS attacks for UEs attempting to connect to a network (e.g., SNPN) when the network is not a PLMN (e.g., when the network is a SNPN) and / or when the desired or initial connection protocol sought between the UE and the network is non-3GPP. In the event that the network cannot be trusted to provide a waiting time for the UE to respond to a control message, a suspected DoS attacker (e.g., a malicious network) may know the predetermined waiting time and simply intercept a control message sent from the UE at a time just outside the predetermined waiting time for sending another control message.

[0037] Currently, 3GPP standard TS24.501 (the entire contents of which are hereby incorporated by reference for all purposes) does not have a robust method for reducing or preventing denial of service (DoS) attacks against such cellular systems and networks. A particular vulnerability occurs when a UE sends a request for the UE to register with a network, and instead of the expected network responding to the UE's registration request, the malicious or pseudo network responds with an unsolicited or unsolicited registration rejection message. In this situation, under current standards and network protocols, the UE may receive the request and respond immediately by sending the same request a second time, or may respond with a second request for connection via a different protocol. In this case, the malicious or pseudo network is ready and waiting for a repeated request or a second request from the UE, and a malicious or pseudo base station may be deployed to intercept the registration request. Once the malicious or pseudo base station receives the repeated or second registration request from the UE, the malicious or pseudo base station may send a message back to the UE indicating acceptance of the registration request, authentication information, connection protocol information, etc. In turn, the UE is likely to determine that the malicious or fake base station is actually part of a real, approved network and will connect to the malicious or fake network via the malicious or fake base station, thereby compromising the UE and any data or information stored thereon or sent from / to the UE.

[0038] Other approaches have been discussed for preventing such DoS attacks and subsequent vulnerabilities at the UE level, such as the methods in International Patent Application No. 2019 / 004901 (hereinafter referred to as the "901 Publication") and Change Request C1-193912 (hereinafter referred to as the "912CR") agreed upon at the 117th meeting of 3GPP TSG-CT WG1 held in Reno, NV, USA from May 13 to 17, 2019, the entire contents of each article are incorporated herein by reference.

[0039] According to the "901 Publication", the network provides optional control signaling that indicates a certain waiting time that the wireless communication device should wait before sending a certain control message to the network device. In turn, the UE can accept or reject the certain waiting time before sending a certain control message, and send the control message to the network device after the waiting time. Alternatively, the UE can reject the certain waiting time specified by the network and instead use a default waiting time or trigger an error handline procedure in response to a suspected DoS attack. However, since the network provides a certain waiting time, and since the waiting time is static and predetermined by the network as a safe time (after which the control message is sent), a malicious network or a pseudo access point (e.g., a base station, a gNodeB, etc.) can simply send an unsolicited rejection message to the UE, wait for a certain time standardized by the network, and then intercept repeated or new control messages, and continue to conduct DoS attacks or attempt to establish a malicious connection with the UE by registering the UE to a pseudo access point, as well as other possible malicious behaviors. Furthermore, since the network provides a certain waiting time, the malicious or fake network may be the network that provides the certain waiting time, and the malicious or fake network may simply wait for the known certain waiting time, intercept the delayed control message, and continue the DoS attack, attempting to establish a malicious connection with the UE by registering the UE to a fake access point, etc. Therefore, the systems, methods, and devices described in the "901 Publication" do not propose a robust method for reducing or eliminating DoS attacks based on vulnerabilities associated with malicious rejection messages in response to UE sending a registration request.

[0040] Regarding "912CR", the method described explicitly applies only to PLMNs and actually indicates that "the UE may request the use of Mobile Initiated Connection Only (MICO) mode during the registration process (see 3GPP TS23.501 and 3GPP TS23.502)" and "the UE should not request the use of MICO mode on non-3GPP accesses". In other words, "912CR" indicates that the MICO mode can only be used with public networks and not with non-public networks, which will impose restrictions in terms of network access and UE security if it is desired or necessary to connect to a non-public (e.g., non-3GPP) network. As described in "912CR", the UE can use a single counter for the "SIM / USIM is considered invalid for GPRS services" event and a single counter for the "SIM / USIM is considered invalid for 5GS services on non-3GPP access" event. For each PLMN-specific counter whose value is greater than zero and less than a UE implementation specific maximum value, the UE shall remove the corresponding PLMN from the forbidden PLMN list, and for each PLMN-specific attempt counter for non-3GPP access whose value is greater than zero and less than a UE implementation specific maximum value, the UE shall remove the corresponding PLMN from the forbidden PLMN list for non-3GPP access.

[0041] As described herein, the methods, apparatus, and computer program products of at least some example embodiments address this and other problems and limitations of conventional approaches by providing a UE with a method of generating a randomly selected wait time from a pre-approved wait time range, thereby removing a network identification or entry from a temporarily banned network list or a permanently banned network list based on whether a counter value is between zero and a randomly selected UE achieving a specific maximum value (e.g., a randomly selected UE associated with the specific network and the specific control message attempt achieving a specific maximum value).

[0042] Some embodiments will now be described more fully below with reference to the accompanying drawings, in which some but not all embodiments of the present disclosure are shown. In fact, various embodiments of the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; on the contrary, these embodiments are provided so that the present disclosure will satisfy applicable legal requirements. The same figure numbers always refer to the same elements. As used herein, the terms "data", "content", "information" and similar terms may be used interchangeably to refer to data that can be sent, received and / or stored according to embodiments of the present disclosure. Therefore, the use of any such terms should not be considered to limit the spirit and scope of the embodiments of the present disclosure.

[0043] In addition, as used herein, the term "circuit" refers to: (a) a hardware circuit implementation only (e.g., an implementation of analog and / or digital circuits); (b) a combination of a circuit and a computer program product, the computer program product including software and / or firmware instructions stored on one or more computer-readable memories, which work together to cause the device to perform one or more functions described herein; and (c) a circuit, such as a microprocessor or a portion of a microprocessor, which requires software or firmware to operate even if the software or firmware is not physically present. This definition of "circuit" applies to all uses of the term herein, including use in any claims. As another example, as used herein, the term "circuit" also covers an implementation including one or more processors and / or portions thereof and their accompanying software and / or firmware. As another example, the term "circuit" as used herein also includes, for example, a baseband integrated circuit or an application processor integrated circuit for a mobile phone, or similar integrated circuits in a server, cellular network device, other network device, field programmable gate array, and / or other computing device.

[0044] As defined herein, "computer-readable storage media" refers to physical storage media (eg, volatile or non-volatile storage devices), which may be distinguished from "computer-readable transmission media," which refers to electromagnetic signals.

[0045] Reference now Figure 1 , which shows an example system supporting communication between a UE and one or more access points, each of which can communicate with one or more stations. These access points can in turn communicate with one or more networks. Although the access points can communicate via a Long Term Evolution (LTE) or Advanced LTE (LTE-A) network, other networks can also support communication between access points, including those configured according to Wideband Code Division Multiple Access (W-CDMA), CDMA2000, Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), IEEE 802.11 standards (e.g., including IEEE 802.11ah or 802.11ac standards or other updated amendments to the standards), wireless local area networks (WLANs), Worldwide Interoperability for Microwave Access (WiMAX) protocols, Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN), etc.

[0046] The access point and the UE can communicate via wired communication, but most commonly via wireless communication. For example, the access point and the UE can communicate in a sub-1 GHz band as defined by the IEEE 802.11ah standard or in a 5 GHz band, for example, as defined by the IEEE 802.11ac standard. The access point can be embodied by any of a variety of network entities, such as an access point, a base station, a Node B, a gNodeB (gNB), a radio network controller (RNC), a mobile device / station (e.g., a mobile phone, a smart phone, a portable digital assistant (PDA), a pager, a laptop computer, a tablet computer, or any of many other handheld or portable communication devices, computing devices, content generation devices, content consumption devices, or a combination thereof). The UE can also be embodied by a variety of devices, such as sensors, meters, etc. Sensors and meters can be deployed in a variety of different applications, including as gas meters, water meters, electricity meters, etc. in utility applications, in environmental and / or agricultural monitoring applications, in industrial process automation applications, in healthcare and fitness applications, in building automation and control applications, and / or in temperature sensing applications. In some embodiments, a station embodied by a sensor or meter may be utilized to backhaul sensor and meter data. Alternatively, the UE may be embodied by a mobile terminal such as a mobile communication device, for example, a mobile phone, a smart phone, a portable digital assistant (PDA), a pager, a laptop computer, a tablet computer, or any of many other handheld or portable communication devices, computing devices, content generation devices, content consumption devices, or a combination thereof. In embodiments where the UE is embodied by a mobile terminal, communications between the access point and the UE may be used to extend the range of a wi-fi or another wireless local area network (WLAN), such as by extending the range of a hotspot, and may be used to offload traffic that would otherwise be carried by a cellular or other network.

[0047] The access point and / or UE may be embodied as or otherwise include apparatus 202, such as Figure 2 Box Figure 1 As generally represented, the device 202 is specifically configured to perform the functions of the corresponding device. Although the device can be used, for example, by an access point or a UE, it should be noted that the components, devices or elements described below may not be mandatory, and therefore some may be omitted in certain embodiments. In addition, some embodiments may include further or different components, devices or elements in addition to those shown and described herein.

[0048] A method for handling a rejection message that is not integrity protected in a non-public network is disclosed. In some embodiments, the method may generally include: generating a randomly selected waiting time from a pre-approved waiting time range, and then removing a network identifier or entry from a temporarily banned network list or a permanently banned network list based on whether a counter value is between zero and a UE-specific maximum value (e.g., a UE-specific maximum value associated with the particular network and the particular control message attempt), and / or sending a control message after the randomly selected waiting time if the counter value is below the UE-specific maximum value. Reference is made to Figure 1 Example embodiments are provided.

[0049] Figure 1 An example of a portion of a 5G wireless network 100 is depicted in accordance with some example embodiments.

[0050] The 5G wireless network 100 may include a user equipment (UE) 102 configured to wirelessly couple to a radio access network (RAN) 104 (also referred to as a core network 104) served by a wireless access point 106 (such as a wireless base station, a wireless local area network access point, a home base station, and / or other types of wireless access points).

[0051] The network 100 may include a core network 104, which may include features not shown, such as an access and mobility management function (AMF), a visit session management function (V-SMF), an access policy control function (v-PCF), a visit network slice selection function (v-NSSF), and / or a visit user plane function (V-UPF). In some embodiments, these devices may be associated with a stand-alone non-public network (SNPN).

[0052] In some embodiments, the network 100 and / or the core network 104 may include devices having functions to support a home public land mobile network (HPLMN) and corresponding functions for "home" wireless local area network (WLAN) access, offload, and / or non-3GPP access. These devices may include features not shown, such as a local SMF, a local PCF, a local NSSF, unified data management, an authentication server function (AUSF), an application function (AF), a local user plane function (H-UPF), and a data network (DN).

[0053] Figure 1Also depicted is a pseudo access point 108 that is not associated with the core network 104 and, much like the wireless access point 106, is configured to communicate with the UE 102 via a set of architectures, via a node, or via other service interfaces. While there are reasons why the pseudo access point 108 may be collocated near a real access point 106 or near a suspected location of the UE 102, the pseudo access point 108 may be located anywhere as long as it is wirelessly accessible to the UE 102 for the purpose of sending and receiving communications, control messages, service requests, etc.

[0054] Figure 1 Also depicted are service interfaces such as 110, 112, and 116. The architecture, nodes (e.g., AMF, V-PCF, H-PCF, H-SMF, and V-SMF, and other devices), and service interfaces may be defined according to standards such as 3GPP TS 23.501 or 3GPP TS 24.501, however other standards as well as proprietary interfaces may be used.

[0055] A network slice refers to a logical network that provides specific network capabilities and network characteristics. A network slice can be considered as a logical end-to-end network that can be created dynamically so that a given UE can access different network slices through the same radio access network (e.g., through the same radio interface). Network slices can provide different services and / or have different QoS needs / requirements. 3GPP TS23.501 - System architecture for 5G systems describes an example of network slicing.

[0056] The UE's subscription information may specify configuration information related to the number, QoS type, and / or identity of network slices. The UE's configuration information (provided by the network when registering in a network such as an SNPN or PLMN) may include one or more network slice identifiers, such as one or more single NSSAIs (S-NSSAIs).

[0057] When the UE 102 sends the registration request 110, the registration request 110 may be received or intercepted by both the real access point 106 and the fake access point 108. In some embodiments, the registration request 110 may include a registration request (REGISTRATION REQUEST) that is not encrypted. Since the UE 102 is searching for a specific network (e.g., the core network 104), the UE 102 will expect a response message from the core network 104 or an entity of the core network 104 (such as the real access point 106). In some embodiments, the UE 102 may expect a message accepting the request to register with the network 104, or alternatively a message rejecting the request to register with the network 104. There are many reasons why the network 104 may reject the registration request 110, among which non-limiting choices are that the network 104 is not ready or cannot accept new user equipment at this time, the access point 106 is not operating correctly or has insufficient bandwidth to manage the registration process or relay such a request, the authentication information or identification information provided by the UE 102 along with the registration request 110 is incorrect or unverifiable at this time, etc. However, while the UE 102 may be expecting a response from the network 104 or its network device (e.g., the real access point 106), the UE 102 may instead receive an unsolicited rejection message 112 from the pseudo access point 108 in response to sending the registration request 110. In some embodiments, the unsolicited rejection message 112 may include a non-access stratum (NAS) rejection message (REJECT MESSAGE), such as a NAS rejection message involving a 5GMM rejection cause value #7 (which refers to the reason "5GS service is not allowed"). As described herein, the NAS is the highest layer of the control plane between the UE and the mobility management entity (MME), and may be used to support the mobility of the UE and to support session management procedures for establishing and maintaining IP connectivity between the UE and, for example, a packet data network gateway (PDN GW). In some embodiments, such a REGISTRATION REJECT message should be processed by the receiving 5GMM entity in the UE 102, which in turn deletes the 5GMM context (e.g., network information and access credentials) and considers the Universal Subscriber Identity Module (USIM) invalid for 5GS services until it is turned off or the Universal Integrated Circuit Card (UICC) containing the USIM is removed from the UE 102, according to the description of the UE 102 behavior under 3GPP TS 24.501, for example. Under 3GPP TS 24.501, the alternative is to silently discard the unsolicited NAS reject message (e.g., reject message 112), which would mean that the UE 102 cannot verify whether the NAS reject message is sent by a genuine or fake / malicious network or access point.

[0058] Typically, under the current 3GPP standards, in order to prevent a pseudo network from controlling USIM validity and a prohibited PLMN list for a UE, the UE may maintain a counter and a timer (e.g., a T3247 timer) having a random value uniformly drawn from a predetermined range between 30 minutes and 60 minutes. Furthermore, under the current 3GPP standards, when the UE receives a rejection message without integrity protection, the UE may start a timer (e.g., T3247) and immediately attempt to register to the same network via other access types (e.g., 3GPP access or non-3GPP access, depending on the access type first attempted before receiving the rejection message). Under the current 3GPP standards, after the timer expires, the UE may attempt to register to the same network unless the counter prohibits the UE from attempting to register.

[0059] While this approach under the current 3GPP standards can be useful for PLMNs, there is currently no method that can provide this protection for non-public networks such as SNPNs. For example, the method described in 3GPP TS24.501 and all other current methods are insufficient for use with non-public networks because there are fundamental differences in the way user information is stored.

[0060] With respect to how user data is stored along with a PLMN identity versus a non-public network entity (e.g., a SNPN entity), for a PLMN, a single SUPI and associated credentials are stored in the USIM and used to register to all PLMNs, whereas for a non-public network such as a SNPN, a single SUPI and associated credentials (an entry in a “user data list” that may be stored in the UE via any suitable storage medium) are used to register with the non-public network, with a different set of “SUPIs and associated credentials” being used for each non-public network 102 (hereinafter also referred to as “SNPN 102”).

[0061] For example, the method described in 3GPP TS24.501 and all other current methods are not sufficient for use with non-public networks, because the UE 102 can communicate with the PLMN in MICO mode to enable a quasi-secure channel for communication regarding REGISTRATION REQUESTS, and the UE 102 will receive an "integrity-verified" rejection message under this channel, which can be received and trusted for the purpose of validating or invalidating the USIM for 5GS services and registration with the PLMN, but not for the non-public network 104. Although the UE's position of rejecting all networks from which it receives a rejection message is problematic, there is currently no way to trust the rejection message from the non-public network 104 (e.g., SNPN 104) in order to manage the validity / invalidity of the USIM and list / cross out the network on the temporary / permanent banned network list managed by the UE 102. Due to these and other differences in public networks (e.g., PLMNs) and non-public networks 104 (e.g., SNPNs 104), current 3GPP standards and other currently available protocols and methods are insufficient to reduce or prevent DoS attacks resulting from the UE 102 receiving a malicious rejection message 112 in response to sending a REGISTRATION REQUEST 110 to a non-public network 104 and retrying the REGISTRATION REQUEST 110 to a malicious network or fake access point 108, resulting in repeated DoS or successful registration and / or connection of the UE 102 with a spoofed access point 108. If the malicious network or spoofed access point 108 can impersonate a spoofed Basic Service Set Identifier (BSSID) or Radio Message Authentication Code (MAC) address, or other credentials that can be “verified” against a list of authorized or trusted non-public networks stored at the UE 102, the UE 102 will trust the malicious network or spoofed access point 108 and will be vulnerable to other attacks, loss of UE user's data, damage to the UE 102, etc.

[0062] Thus, systems, devices, methods, and computer programs are described and illustrated herein for preventing DoS attacks on a UE 102 that receives a rejection message 112 without integrity protection from a pseudo access point 108. In some embodiments, when the UE 102 receives the rejection message 112 without integrity protection, the UE 102 starts a timer and operates according to the corresponding counter value, the received 5GMM rejection cause value, and the access type (e.g., 3GPP or non-3GPP access). In some embodiments, the existing timer T3247 can be reused for this purpose.

[0063] In some embodiments, in contrast to the method for validating the USIM for a non-public network 104 (e.g., SNPN 104), for each entry in the "Subscriber Data List" stored at the UE 102, the UE 102 maintains one counter for the "entry for the current SNPN is considered invalid for 3GPP access" event and one counter for the "entry for the current SNPN is considered invalid for non-3GPP access" event. Thus, in some embodiments, the validity of the subscription information is managed separately for each non-public network 104 (e.g., SNPN 104). In the case of a PLMN and a conventional method for preventing such a DoS attack on a UE 102 attempting to register with the PLMN, the UE 102 is configured to use only a single counter for the "SIM / USIM is considered invalid for GPRS service" event and a single counter for the "SIM / USIM is considered invalid for 5GS service on non-3GPP access" event. Thus, according to conventional practice for PLMNs, once the subscription information in the USIM is considered invalid for one PLMN, the subscription information in the USIM is also considered invalid for other PLMNs. In contrast, according to the methods described herein and in the claims, the UE 102 may invalidate the USIM for a particular non-public network 104 (eg, SNPN 104) without invalidating the USIM for other non-public networks.

[0064] In some embodiments, when an entry of the "User Data List" is reconfigured or removed, if the value of the SNPN-specific attempt counter for 3GPP access for the SNPN 104 corresponding to the entry is greater than zero and less than the UE implementation-specific maximum value, the UE 102 shall remove the SNPN identity corresponding to the entry from the "Permanently Prohibited SNPN" list. In some embodiments, if the value of the SNPN-specific attempt counter for non-3GPP access for the SNPN 104 corresponding to the entry is greater than zero and less than the UE implementation-specific maximum value, the UE 102 shall remove the SNPN identity corresponding to the entry from the "Permanently Prohibited SNPN" list for non-3GPP access.

[0065] In the case of a conventional method for preventing DoS attacks against UEs attempting to connect to a PLMN, when the USIM is removed or otherwise reset, for each PLMN-specific attempt counter whose value is greater than zero and less than a UE implementation-specific maximum value, the UE 102 should remove the corresponding PLMN from the forbidden PLMN list, and for each PLMN-specific attempt counter for non-3GPP access whose value is greater than zero and less than a UE implementation-specific maximum value, the UE should remove the corresponding PLMN from the forbidden PLMN list for non-3GPP access.

[0066] In addition, as discussed in more detail below, the UE 102 responds to receiving the rejection message 112 and determines that the rejection message 112 is not integrity protected because NAS security is not provided, such as encrypting NAS signaling messages that can serve as security parameters for authentication. Under the 3GPP protocol, integrity protection and encryption can be bound together in the EPS security context (established between the UE 102 and the MME) and identified by a key set identifier. Therefore, it is generally impossible to establish an EPS security context between the UE 102 and the SNPN 104. In the context of the PLMN, the EU102 can communicate with the PLMN in MICO mode, which means that the rejection message 112 received from the PLMN is likely to have integrity protection and encryption when received. In contrast, since the authentication information and identification information are different for each SNPN 104, the UE 102 cannot form a secure or quasi-secure communication channel with the SNPN 104 so that the SNPN 104 sends a rejection message 112 with integrity protection and encryption.

[0067] Thus, the UE 102 may be configured to adhere to a protocol by which a random value is selected from a range of pre-approved values ​​associated with the wait time 114 for which the UE 102 should wait before sending another control message to the SNPN 104 or its access point 106. If, after waiting for the timer 114, the UE 102 determines that the counter is not above a UE-approved threshold for the particular network type (e.g., public versus non-public) and connection type (e.g., 3GPP versus non-3GPP) for which the UE 102 is requesting registration, the control message is resent to the access point 106 to request registration with the network 104.

[0068] Once the network 104 and / or the genuine access point 106 are determined by the UE 102 to be unlikely to be the spoofed access point 108, the UE 102 can resend the control message. Once the network 104 approves the UE 102 to register with the network 104, the UE 102 can begin to operate in a connected (CONNECTED) mode, receive services from a service provider according to a service-based architecture (SBA) (e.g., 5GSBA) of the network 104, and utilize the network 104 to communicate with the network 104 and with the Internet 118 and / or other resources and services.

[0069] Reference now Figure 2 , which provides a block diagram of an apparatus 202 according to some example embodiments. The apparatus 202 may represent a user equipment, such as the user equipment 102. The apparatus 202 or portions thereof may be implemented in other network nodes, including base station access points 106 / WLAN access points and other network devices, or other portions of the SNPN 104 itself.

[0070] As shown, the device 202 may include a processor 204 that communicates with the memory 206 and is configured to provide signals to and receive signals from the communication interface 208. In some embodiments, the communication interface 208 may include a transmitter and a receiver. In some embodiments, the processor 204 may be configured to at least partially control the functions of the device 202. In some embodiments, the processor 204 may be configured to control the functions of the transmitter and the receiver by affecting control signaling via electrical leads to the transmitter and the receiver. Similarly, the processor 204 may be configured to control other elements of the device 10 by affecting control signaling via electrical leads connecting the processor 204 to other elements (such as a display or memory 206). The processor 204 may be embodied in various ways, including circuits, at least one processing core, one or more microprocessors with an accompanying digital signal processor, one or more processors without an accompanying digital signal processor, one or more coprocessors, one or more multi-core processors, one or more controllers, processing circuits, one or more computers, various other processing units including integrated circuits (e.g., application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), etc.), or some combination thereof. Therefore, although in Figure 2 2 is illustrated as a single processor, however in some example embodiments, processor 20 may include multiple processors or processing cores.

[0071] The apparatus 202 may be capable of operating with one or more air interface standards, communication protocols, modulation types, access types, etc. The signals sent and received by the processor 204 may include signaling information in accordance with the air interface standard of the applicable cellular system and / or any number of different wired or wireless network technologies, including but not limited to Wi-Fi, wireless local access network (WLAN) technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11, 802.16, 802.3, ADSL, DOCSIS, etc. In addition, these signals may include voice data, user-generated data, user-requested data, etc.

[0072] For example, the device 202 and / or the cellular modem therein may be capable of operating in accordance with various first generation (1G) communication protocols, second generation (2G or 2.5G) communication protocols, third generation (3G) communication protocols, fourth generation (4G) communication protocols, fifth generation (5G) communication protocols, Internet Protocol Multimedia Subsystem (IMS) communication protocols (e.g., Session Initiation Protocol (SIP)), etc. For example, the device 10 may be capable of operating in accordance with 2G wireless communication protocols IS-136, Time Division Multiple Access TDMA, Global System for Mobile Communications GSM, IS-95, Code Division Multiple Access CDMA, etc. In addition, for example, the device 10 may be capable of operating in accordance with 2.5G wireless communication protocols General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), etc. In addition, for example, the device 202 may be capable of operating according to 3G wireless communication protocols, such as Universal Mobile Telecommunications System (UMTS), Code Division Multiple Access 2000 (CDMA2000), Wideband Code Division Multiple Access (WCDMA), Time Division Synchronous Code Division Multiple Access (TD-SCDMA), etc. In addition, the device 202 may be capable of operating according to 3.9G wireless communication protocols, such as Long Term Evolution (LTE), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), etc. In addition, for example, the device 202 may be capable of operating according to 4G wireless communication protocols (such as Advanced LTE, 5G, etc.) and similar wireless communication protocols that may be developed later.

[0073] It should be understood that the processor 204 may include circuits for implementing the audio / video and logic functions of the device 202. For example, the processor 204 may include a digital signal processor device, a microprocessor device, an analog-to-digital converter, a digital-to-analog converter, etc. The control and signal processing functions of the device 202 may be allocated between these devices according to their respective capabilities. In addition, the processor 204 may include an internal voice coder (VC) 20a, an internal data modem (DM) 20b, etc. In addition, the processor 204 may include the functionality to operate one or more software programs, which may be stored in the memory 206. In general, the processor 204 and the software instructions stored in the memory 206 may be configured to cause the device 202 to perform actions. For example, the processor 204 may be capable of operating a connection program such as a web browser. The connection program may allow the device 202 to send and receive web content (such as location-based content) according to a protocol (such as a wireless application protocol, WAP, a hypertext transfer protocol, HTTP, etc.).

[0074] The device 202 may also include a user interface, which may include, for example, a headset or speaker, a ringer, a microphone, a display, a user input interface, etc., which may be operatively coupled to the processor 204. As described above, the display may include a touch-sensitive display, wherein the user may touch and / or gesture to make a selection, input a value, etc. The processor 204 may also include a user interface circuit configured to control at least some functions of one or more elements of a user interface such as a speaker, a ringer, a microphone, a display, etc. The processor 204 and / or the user interface circuit including the processor 204 may be configured to control one or more functions of one or more elements of the user interface via computer program instructions (e.g., software and / or firmware) accessible to the processor 204 stored on the memory 206 (e.g., volatile memory, non-volatile memory, devices including them, etc.). The device 202 may include a battery for powering various circuits related to the mobile terminal (e.g., a circuit that provides mechanical vibration as a detectable output). The user input interface may include devices that allow the apparatus 202 to receive data, such as a keypad (eg, a virtual keyboard presented on a display or an externally coupled keyboard) or the like.

[0075] like Figure 2 As shown in , the device 202 may also include one or more mechanisms for sharing and / or obtaining data, which are illustrated as communication interfaces 208. For example, the communication interface 208 of the device 202 may include a short-range radio frequency (RF) transceiver and / or interrogator, so that data can be shared with and / or obtained from the electronic device based on RF technology. The device 202 may include other short-range transceivers, such as infrared (IR) transceivers, Bluetooth transceivers, etc. TM Wireless technology operated by Bluetooth TM (BT) transceiver, wireless universal serial bus (USB) transceiver, Bluetooth TM Low power transceiver, ZigBee transceiver, ANT transceiver, cellular device to device transceiver, wireless LAN link transceiver and / or any other short-range radio technology. The device 202 (particularly a short-range transceiver) may be able to send data to and / or receive data from an electronic device near the device (such as within about 10 meters). The device 202 including a Wi-Fi or wireless LAN modem may also be able to send and / or receive data to / from an electronic device according to various wireless network technologies (including 6LoWpan, Wi-Fi, Wi-Fi low power, WLAN technology (such as IEEE 802.11 technology, IEEE802.15 technology, IEEE 802.16 technology), etc.).

[0076] The device 202 may include other memories, such as a user identity module (SIM), a removable user identity module (R-UIM), an eUICC, a UICC, etc., which may store information elements related to mobile users. In addition to the SIM, the device 202 may include other removable and / or fixed memories. The device 202 may include volatile memory and / or non-volatile memory, which may include some or all of the memory 206, or may alternatively be a separate memory within the device 202 or connected to the device 202. For example, the volatile memory may include random access memory (RAM) (including dynamic and / or static RAM), on-chip or off-chip cache memory, etc. Non-volatile memory that may be embedded and / or removable may include, for example, read-only memory, flash memory, magnetic storage devices (e.g., hard disks, floppy disk drives, tapes), optical drives and / or optical media, non-volatile random access memory (NVRAM), etc. Like volatile memory, non-volatile memory may include a cache area for temporarily storing data. At least a portion of the volatile and / or non-volatile memory may be embedded in the processor 204. The memory may store one or more software programs, instructions, information segments, data, etc. that may be used by the apparatus to perform the operations disclosed herein. Alternatively or additionally, the apparatus 202 may be configured to cause the operations disclosed herein with respect to the base station 106 / WLAN access point 106 and network nodes including the UE 102.

[0077] The memory may include an identifier that can uniquely identify the device 202, such as an International Mobile Equipment Identity (IMEI) code. The memory may include an identifier that can uniquely identify the device 202, such as an International Mobile Equipment Identity (IMEI) code. In an example embodiment, the processor 204 may be configured using computer code stored at the memory, and / or the processor 204 may be configured to provide the operations disclosed herein with respect to the base station 106 / WLAN access point 106 and the network nodes including the UE 102. Similarly, the device 202 may be configured as any other component or network device from the SNPN 104.

[0078] Some embodiments disclosed herein may be implemented in software, hardware, application logic, or a combination of software, hardware, and application logic. For example, the software, application logic, and / or hardware may reside on the memory 206, the control device 204, or an electronic component. In some example embodiments, the application logic, software, or instruction set is maintained on any of a variety of conventional computer-readable media. In the context of this document, the term "computer-readable medium" is used interchangeably with reference to the accompanying drawings. Figure 2As depicted in the example, "computer-readable media" can be any non-transitory media that can contain, store, communicate, propagate, or transport instructions for use by or in conjunction with an instruction execution system, apparatus, or device (such as a computer or data processor circuit), and computer-readable media can include non-transitory computer-readable storage media, which can be any medium that can contain or store instructions for use by or in conjunction with an instruction execution system, apparatus, or device (such as a computer).

[0079] Without limiting in any way the scope, interpretation, or application of the claims appearing below, the technical effect of one or more of the example embodiments disclosed herein may be an improved UE configuration. References to "UE 102" hereinafter are understood to apply and also refer to "device 202". Therefore, any embodiment of the method, system, means, apparatus, device, or computer program described or illustrated herein is understood to include any or all components, functions, elements, or steps of any other embodiment, so that any method may be performed by UE 102, by device 202, or by any other suitable system or device, and may likewise be performed according to computer program code contemplated within the scope of the present disclosure.

[0080] In some embodiments, UE 102 may be configured to operate in a SNPN access mode, wherein UE 102 is configured to request, establish, and maintain access, connections, communication channels, and pathways for service provision with network devices and network entities.

[0081] In some embodiments, if the UE 102 operates in SNPN access mode, the UE 102 shall maintain at least one of the following counters for each entry in the "User Data List":

[0082] a) one SNPN specific attempt counter for 3GPP type access, which is configured to count access attempts via 3GPP access only;

[0083] b) an SNPN specific attempt counter for non-3GPP type access, which is configured to count access attempts via non-3GPP access only;

[0084] c) a counter for the event that the current SNPN entry is considered invalid for 3GPP access, and

[0085] d) A counter for the event that the current SNPN entry is considered invalid for non-3GPP access.

[0086] In some embodiments, UE 102 may or should store the above counter in its non-volatile memory. In some embodiments, when the entry with the corresponding SNPN identifier of the "User Data List" is reconfigured or removed, UE 102 should erase the attempt counter and reset the event counter to "zero". In some embodiments, the counter value should not be affected by the activation or deactivation of MICO mode or power saving mode (e.g., see 3GPP TS24.301).

[0087] In some embodiments, the UE implementation specific maximum value of any of the above counters should not be greater than 10. In some embodiments, different counters may use different UE implementation specific maximum values. In other words, in some embodiments, the UE implementation specific maximum value may be different between different network types (e.g., PLMN, SNPN) and / or between different access protocols (e.g., 3GPP, non-3GPP).

[0088] In some embodiments, if UE 102 receives a rejection message (sometimes referred to as a reject message) from the network, such as after sending a registration request or a request for service to UE 102, UE 102 can evaluate the rejection message to determine whether to believe that the message is from a reputable network, determine the reason for receiving the rejection message, and / or determine whether another similar and / or different message regarding the registration or service request can be sent to the network. For example, in the context of a 5G network, if UE 102 receives a REGISTER REJECT or SERVICE REJECT message without integrity protection due to selecting one or more of the 5GMM cause values ​​(e.g., #3, #6, #12, #15, #72, #74, or #75), then before the network 104 has established a secure exchange of NAS messages for the N1 NAS signaling connection, if the timer is not running, UE 102 will start timer T3247 (e.g., see 3GPP TS 24.008) with a random value uniformly drawn from a range between two predetermined wait time values ​​(e.g., 30 minutes and 60 minutes), and take the following actions:

[0089] A) If the received 5GMM cause value is #3 or #6:

[0090] a. If a 5GMM cause value is received via 3GPP access and:

[0091] i. If the value of the counter for the event "the entry for the current SNPN is considered invalid for 3GPP access" is less than a UE implementation specific maximum value, the UE 102 may or should:

[0092] ●Set the 5GS update status to 5U3 ROAMING NOT ALLOWED

[0093] (and should store it), and the 5G Globally Unique Temporary Identity (5G-GUTI) for 3GPP access, the last visited registration tracking area identifier,

[0094] (TAI), TAI list, and key set identifier (ngKSI);

[0095] ● Increment for "The current SNPN entry is considered invalid for 3GPP access"

[0096] Counter of events;

[0097] ● reset the registration attempt counter in case of a registration rejection message;

[0098] ● Store the current TAI in the "5GS Prohibited Tracking Area for Roaming" list for the current SNPN and enter 5GMM-

[0099] DEREGISTERED.LIMITED-SERVICE status; and

[0100] · Search for a suitable cell in another tracking area according to 3GPP TS 38.304 or 3GPP TS 36.304. As a UE implementation option, if non-3GPP access is available, the UE has not registered to the current SNPN through the non-3GPP access, and the entry of the "User Data List" with the SNPN identification of the current SNPN is not considered invalid for the non-3GPP access, then the UE may make a registration attempt through the non-3GPP access; or

[0101] ii. Otherwise, the UE 102 may or should continue to operate as if the message was integrity protected;

[0102] b. If a 5GMM cause value is received via non-3GPP access and:

[0103] i. If the entry for "Current SNPN is considered invalid for non-3GPP access"

[0104] If the value of the counter for an event is less than a UE implementation specific maximum value, the UE 102 shall:

[0105] Set the 5GS update status to 5U3 ROAMING NOT ALLOWED

[0106] (and should store it), and the 5G-GUTI for non-3GPP access, the last visited registered TAI, the TAI list, and the ngKSI should be deleted;

[0107] Enter the 5GMM-DEREGISTERED LIMITED-SERVICE state;

[0108] as well as

[0109] · The entry for "Current SNPN is considered invalid for non-3GPP access"

[0110] The counter of the event is incremented by 1. As a UE implementation option:

[0111] a. If another access point for non-3GPP access is available, the UE may attempt to register to the other access point through non-3GPP access (the UE may select another non-3GPP access point based on UE implementation-specific means);

[0112] or

[0113] b. If 3GPP access is available, the UE has not registered to the current SNPN via 3GPP access, and the entry of the current "User Data List" with the SNPN identification of the current SNPN is not considered invalid for 3GPP access, the UE may attempt to register to the same network via 3GPP access to which non-3GPP access is not allowed; or

[0114] ii. Otherwise, the UE 102 shall continue to operate as if the message is integrity protected;

[0115] B) If the received 5GMM cause value is #12 or #15, the UE 102 shall continue to operate as if the message was integrity protected. In addition:

[0116] 1) If a 5GMM cause value is received via 3GPP access, non-3GPP access is available, the UE has not registered to the current SNPN via the non-3GPP access, and the entry of the "User Data List" with the SNPN identifier of the current SNPN is not considered invalid for non-3GPP access, then the UE 102 may attempt to register to the current SNPN via the non-3GPP access; or

[0117] 2) If a 5GMM cause value is received via non-3GPP access, 3GPP access is available, UE 102 has not registered to the current SNPN via 3GPP access, and the entry of the "User Data List" with the SNPN identifier of the current SNPN is not considered invalid for 3GPP access, then UE 102 may attempt to register to the current SNPN via 3GPP access;

[0118] C) If the received 5GMM cause value is #72, the UE shall continue to operate as if the message was integrity protected. Additionally, if the value of the SNPN-specific attempt counter for non-3GPP access for the current SNPN is less than a UE implementation specific maximum value, the UE shall increment the counter; and

[0119] D) If the received 5GMM cause value is #74 or #75:

[0120] 1) If a 5GMM cause value is received over 3GPP access, the UE 102 shall:

[0121] a. Set the 5GS update status to 5U3 ROAMING NOTALLOWED (and store it), and the 5G-GUTI for 3GPP access, the last visited registered TAI, the TAI list, and the ngKSI should be deleted;

[0122] b. Reset the registration attempt counter in case of a registration rejection message;

[0123] c. Store the current TAI in the "5GS Prohibited Tracking Area for Roaming" list for the current SNPN and enter 5GMM-

[0124] DEREGISTERED LIMITED-SERVICE status; and

[0125] d. Search for a suitable cell in another tracking area according to 3GPP TS38.304 or 3GPP TS36.304. As a UE implementation option, if non-3GPP access is available, UE 102 has not registered to the current SNPN through the non-3GPP access, and the entry of the "User Data List" with the SNPN identification of the current SNPN is not considered invalid for non-3GPP access, then UE 102 can attempt to register to the current SNPN through the non-3GPP access; and

[0126] 2) If a 5GMM cause value is received over non-3GPP access, the UE 102 shall:

[0127] a. Set the 5GS update status to 5U3 ROAMING NOTALLOWED (and it should be stored), and the 5G-GUTI for non-3GPP access, the last visited registered TAI, the TAI list, and the ngKSI should be deleted;

[0128] b. Reset the registration attempt counter in case of a registration rejection message; and

[0129] c. Entering the 5GMM-DEREGISTERED LIMITED-SERVICE state. As a UE implementation option, if another access point for non-3GPP access is available, the UE 102 may make a registration attempt through the non-3GPP access (the UE 102 may select another non-3GPP access point based on UE implementation-specific means), or if 3GPP access is available, the UE 102 has not yet registered to the current SNPN through 3GPP access, and the entry of the "User Data List" with the SNPN identifier of the current SNPN is not considered invalid for 3GPP access, then the UE 102 may make a registration attempt through the 3GPP access.

[0130] In some embodiments, upon expiration of timer T3247, UE 102 may or should:

[0131] a. For the current SNPN, erase the list of “5GS prohibited tracking areas for regional service provision” and the list of “5GS prohibited tracking areas for roaming”;

[0132] b. If the value of the counter for the event "the entry of the current SNPN is considered invalid for 3GPP access" is less than the UE implementation-specific maximum value, the entry of the "User Data List" with the SNPN identifier of the current SNPN is set to be valid for 3GPP access;

[0133] c. If the entry for "Current SNPN is considered invalid for non-3GPP access"

[0134] If the value of the counter of the event is less than the UE implementation specific maximum value, the entry of the "User Data List" with the SNPN identifier of the current SNPN is set as valid for non-3GPP access;

[0135] d. If the value of the SNPN-specific attempt counter for 3GPP access to the current SNPN is greater than zero and less than a UE implementation-specific maximum value, and the SNPN identity of the current SNPN is included in the "permanently banned SNPN" list and / or

[0136] If any of the "temporarily banned SNPNs" list is found, the SNPN identifier of the current SNPN is removed from the "permanently banned SNPN" list and / or the "temporarily banned SNPN" list;

[0137] e. if the value of the SNPN-specific attempt counter for non-3GPP access is greater than zero but less than a UE implementation-specific maximum value, and the SNPN identity of the current SNPN is included in any of the “permanently banned SNPN” list for non-3GPP access and / or the “temporarily banned SNPN” list for non-3GPP access, then remove the SNPN identity of the current SNPN from the “permanently banned SNPN” list for non-3GPP access and / or the “temporarily banned SNPN” list for non-3GPP access;

[0138] f. If still needed, start the registration process according to the 5GMM state and 5GS update state, or perform SNPN selection, for example, see 3GPP TS23.122. When UE 102 is turned off:

[0139] a. For each SNPN-specific attempt counter for 3GPP access whose value is greater than zero and less than a UE-implemented specific maximum value, the UE 102 shall remove the corresponding SNPN identity (if any) from the "permanently banned SNPN" list and / or the "temporarily banned SNPN" list; and

[0140] b. For each SNPN-specific attempt counter for non-3GPP access whose value is greater than zero and less than a UE implementation-specific maximum value, the UE 102 shall remove the corresponding SNPN identity (if any) from the “permanently banned SNPN” list and / or the “temporarily banned SNPN” list.

[0141] When an entry in the User Data List is reconfigured or removed:

[0142] a. If the value of the SNPN-specific attempt counter for 3GPP access for the SNPN corresponding to the entry is greater than zero and less than a UE implementation-specific maximum value, the UE shall remove the SNPN identity corresponding to the entry from the "Permanently banned SNPN" list and / or the "Temporarily banned SNPN" list (if any); and

[0143] b. If the value of the SNPN-specific attempt counter for non-3GPP access for the SNPN corresponding to the entry is greater than zero and less than the UE implementation-specific maximum value, the UE shall remove the SNPN identity corresponding to the entry from the "permanently banned SNPN" list for non-3GPP access and / or the "temporarily banned SNPN" list for non-3GPP access (if any).

[0144] Reference now Figure 3 , Figure 3According to a specific embodiment of the present disclosure, a message protocol diagram is shown in which UE 102 issues a registration request (REGISTRATION REQUEST) to an access mobility function (AMF) of a network 104, wherein the AMF may be a component of a base station 106 or accessible through the base station 106. When UE 102 sends the REGISTRATION REQUEST message to the AMF, UE 102 starts the T3510 timer. Thereafter, the AMF receives the REGISTRATION REQUEST message and determines whether the UE 102 can be registered with the network 104 based on the REGISTRATION REQUEST. In the case that the AMF can register the UE 102 with the network 104, the AMF performs authorization of the UE 102 with the network 104. If the AMF allocates a TempID for the request, the AMF starts T3550 upon receiving the REGISTRATION REQUEST and sends a REGISTRATION ACCEPT message back to the UE 102. When UE 102 receives the REGISTRATION ACCEPT message, UE 102 stops the T3510 timer. If the AMF assigns a TempID, UE 102 sends a REGISTRATION COMPLETE message back to the AMF. Upon receiving the REGISTRATION COMPLETE message, the AMF in turn stops the T3550 timer. Conversely, as shown at the bottom of the message diagram, in the event that the AMF determines that the UE 102 cannot register with the network 104, the AMF does not start the timer, but simply responds to the REGISTRATION REQUES message by sending a REGISTRATION REJECT message back to the UE 102. Upon receiving the REGISTRATION REJECT message from the AMF, the UE 102 stops the T3510 timer and increments the counter by a value of 1 based on the network type and access protocol.

[0145] In some embodiments, if UE 102 receives a REGISTRATION ACCEPT message from SNPN 104, UE 102 shall reset the SNPN-specific attempt counter for the specific access type for which the message was received for that SNPN 104. If the message is received via 3GPP access, UE 102 shall reset the counter for the event "the entry for the current SNPN is considered invalid for 3GPP access". If the message is received via non-3GPP access, UE 102 shall reset the counter for the event "the entry for the current SNPN is considered invalid for non-3GPP access".

[0146] In some embodiments, the UE 102 may or should take the following actions depending on the 5GMM cause value received in the REGISTRATION REJECT message:

[0147] #3 (illegal UE) or #6 (illegal ME):

[0148] a. The UE 102 shall set the 5GS update state to 5U3 ROAMING NOTALLOWED (and shall store it), and shall delete any 5G-GUTI, last visited registered TAI, TAI list, and ngKSI. The UE 102 shall consider the entry of the "Subscriber Data List" with the SNPN identification of the current SNPN 104 as invalid until the UE 102 is switched off or the entry is reconfigured or removed. The UE 102 shall enter the 5GMM-DEREGISTERED state.

[0149] If NAS has successfully integrity checked the message, UE 102 shall set the entry for "Current SNPN considered invalid for 3GPP access"

[0150] The counter for the event "Current SNPN entry considered invalid for non-3GPP access" is set to a UE implementation specific maximum value for that particular counter, and the counter for "Current SNPN entry considered invalid for non-3GPP access" is set to a UE implementation specific maximum value for that particular counter.

[0151] #72 (Non-3GPP access to 5GCN is not allowed)

[0152] a. When this cause value is provided in a REGISTRATION REJECT message received over a non-3GPP access, the UE 102 shall set the 5GS Update Status to 5U3

[0153] ROAMING NOT ALLOWED (and it should be stored), and 5G-

[0154] GUTI, last visited registered TAI, TAI list, and ngKSI. In addition, UE 102 shall reset the registration attempt counter and enter 5GMM-

[0155] DEREGISTERED state. If the NAS has successfully integrity checked the message, the UE 102 shall set the SNPN specific attempt counter for non-3GPP access for this SNPN to a UE implementation specific maximum value for this specific counter.

[0156] #74 (Not authorized for this SNPN yet)

[0157] a.5GMM Cause #74 is applicable only when received from a cell belonging to a SNPN. A 5GMM Cause #74 received from a cell not belonging to a SNPN is considered an abnormal case. In some embodiments, the UE 102 shall set the 5GS Update Status to 5U3ROAMING NOT ALLOWED (and shall store it), and shall delete any 5G-GUTI, the last visited registered TAI, the TAI list, and the ngKSI. The UE 102 shall reset the registration attempt counter and store the SNPN identity in the "Temporarily banned SNPN" for the specific access type for which the message was received.

[0158] List of 5GMM-DEREGISTERED PLMNs that UE 102 should enter

[0159] SEARCH state and perform SNPM selection (e.g., according to 3GPP TS

[0160] 23.122). If the NAS has successfully integrity checked the message, the UE 102 shall set the SNPN-specific attempt counter for 3GPP access to the SNPN to the UE implementation specific maximum value for the specific counter, and set the SNPN-specific attempt counter for non-3GPP access to the SNPN to the UE implementation specific maximum value for the specific counter.

[0161] 102 also supports the registration process to the same SNPN through other access, then the UE

[0162] 102 should additionally process the 5GMM parameters and 5GMM status for this access,

[0163] As described for this 5GMM cause value.

[0164] #75 (Permanently not authorized for this SNPN)

[0165] a.5GMM Cause #75 applies only when received from a cell belonging to a SNPN. A 5GMM Cause #75 received from a cell that does not belong to a SNPN is considered an abnormal case. The UE 102 shall set the 5GS Update Status to 5U3 ROAMINGNOTALLOWED (and shall store it), and shall delete any 5G-GUTI, last visited registered TAI, TAI list, and ngKSI. The UE 102 shall reset the registration attempt counter and store the SNPN identity in the "Permanently banned SNPN" list for the specific access type for which the message was received. The UE 102 shall enter the 5GMM-DEREGISTERED.PLMN-SEARCH state and perform SNPN selection (e.g., as per 3GPP TS23.122). If the NAS has successfully integrity checked the message, the UE 102 shall set the SNPN-specific attempt counter for 3GPP access to this SNPN to the UE implementation specific maximum value for the specific counter, and set the SNPN-specific attempt counter for non-3GPP access to this SNPN to the UE implementation specific maximum value for the specific counter. If the NAS has successfully integrity checked the message and the UE 102 also supports registration procedures to the same SNPN 104 over other accesses, the UE 102 shall additionally process the 5GMM parameters and 5GMM state for this access as described for this 5GMM cause value.

[0166] Reference now Figure 4 , Figure 4According to a specific embodiment of the present disclosure, a message protocol diagram is shown in which UE 102 issues a service request (SERVICE REQUEST) to the AMF of the network 104 via access stratum (AS) signaling, wherein the AMF may be a component of the base station 106 or accessible through the base station 106. When UE 102 sends the SERVICE REQUEST message to AMF, UE 102 starts the T3517 timer. Thereafter, AMF receives the SERVICE REQUEST message and determines whether the service can be provided to UE 102 according to the SERVICE REQUEST. In the case that AMF can provide services to UE 102 from network 104, AMF performs authorization of UE 102 with network 104 and relays the service to network 104. In the case that AMF can provide services to UE 102 from network 104, AMF sends a SERVICE ACCEPT message to UE 102 via AS signaling, and UE 102 stops the T3517 timer. In contrast, in the case where UE 102 sends a SERVICE REQUEST message for emergency service fallback, the network 104 or AMF may return an AS indication, and UE 102 may stop the T3517 timer. Alternatively, if UE 102 sends a SERVICE REQUEST message to AMF via AS signaling, and AMF determines that network 104 cannot provide the requested service to UE 102, AMF sends a SERVICE REJECT message to UE 102, and UE 102 stops the T3517 timer.

[0167] In some embodiments, the UE 102 may or should take the following actions depending on the 5GMM cause value received in the SERVICE REJECT message:

[0168] #3 (illegal UE) and #6 (illegal ME):

[0169] a. The UE 102 shall set the 5GS update status to 5U3 ROAMING NOTALLOWED (and shall store it) and shall delete any 5G-GUTI, last visited registered TAI, TAI list, and ngKSI. The UE shall consider the entry of the "User Data List" with the SNPN identifier of the current SNPN as invalid until the UE is switched off or the entry is reconfigured or removed.

[0170] The UE shall enter the 5GMM-DEREGISTERED state. If NAS has successfully integrity checked this message, the UE shall set the counter for the event "The entry for the current SNPN is considered invalid for 3GPP access" and the counter for the event "The entry for the current SNPN is considered invalid for non-3GPP access" to a UE implementation specific maximum value.

[0171] #72 (Non-3GPP access to 5GCN is not allowed):

[0172] a. If the UE initiates the service request procedure via non-3GPP access, the UE shall set the 5GS update status to 5U3ROAMING NOT ALLOWED (and shall store it), and shall delete the 5G-GUTI, the last visited registered TAI, the TAI list, and the ngKSI for non-3GPP access. In addition, for non-3GPP access, the UE shall reset the registration attempt counter and enter 5GMM-

[0173] DEREGISTERED state. If NAS has successfully integrity checked this message, the UE shall set the SNPN-specific attempt counter for non-3GPP access for this SNPN to a UE implementation specific maximum value.

[0174] #74 (not authorized for this SNPN yet):

[0175] a.5GMM Cause #74 is only applicable when received from a cell belonging to a SNPN. A 5GMM Cause #74 received from a cell not belonging to a SNPN is considered an abnormal case. The UE shall set the 5GS Update Status to 5U3 ROAMING NOTALLOWED (and shall store it) and shall delete any 5G-GUTI, last visited registered TAI, TAI list, and ngKSI. The UE shall reset the Registration Attempt Counter and store the SNPN identity in the "Temporarily Prohibited SNPN" list for the specific access type for which this message was received. The UE shall enter 5GMM-

[0176] DEREGISTERED.PLMN-SEARCH state, and according to 3GPP TS

[0177] 23.122 Perform SNPN Selection. If NAS has successfully integrity checked this message, the UE shall set the SNPN-specific attempt counters for 3GPP access to this SNPN and the SNPN-specific attempt counters for non-3GPP access to a UE implementation specific maximum value. If NAS has successfully integrity checked this message and the UE also supports Registration procedures to the same SNPN over other accesses, the UE shall additionally process the 5GMM parameters and 5GMM state for this access as described for this 5GMM cause value.

[0178] #75 (Permanently not authorized for this SNPN):

[0179] a.5GMM Cause #75 is applicable only when received from a cell belonging to a SNPN. A 5GMM Cause #75 received from a cell not belonging to a SNPN is considered an abnormal case. The UE shall set the 5GS Update Status to 5U3 ROAMING NOTALLOWED (and shall store it) and shall delete any 5G-GUTI, last visited registered TAI, TAI list, and ngKSI. The UE shall reset the Registration Attempt Counter and store the SNPN identity in the "Permanently Banned SNPN" list for the specific access type for which this message was received. The UE shall enter 5GMM-

[0180] DEREGISTERED.PLMN-SEARCH state, and according to 3GPP TS

[0181] 23.122 Perform SNPN Selection. If NAS has successfully integrity checked this message, the UE shall set the SNPN-specific attempt counters for 3GPP access to this SNPN and the SNPN-specific attempt counters for non-3GPP access to a UE implementation specific maximum value. If NAS has successfully integrity checked this message and the UE also supports Registration procedures to the same SNPN over other accesses, the UE shall additionally process the 5GMM parameters and 5GMM state for this access as described for this 5GMM cause value.

[0182] In some embodiments, if an EAP Failure message is received in an AUTHENTICATION REJECT message:

[0183] 1) If NAS has successfully performed an integrity check on the message:

[0184] a. The UE shall set the update status to 5U3 ROAMING NOT ALLOWED, delete the stored 5G-GUTI, TAI list, last visited registered TAI and ngKSI. The entry of the "User Data List" with the SNPN identifier of the current SNPN shall be considered invalid until the UE is switched off or the entry is reconfigured or removed; and

[0185] b. The UE shall consider the entry for the current SNPN as invalid for 3GPP access

[0186] The counter for the event and the counter for the event "the entry for the current SNPN is considered invalid for non-3GPP access" are set to a UE implementation specific maximum value; and

[0187] 2) If this message is received without integrity protection, if the timer is not running, the UE shall start timer T3247 with a random value uniformly drawn from the range 30 minutes to 60 minutes. Additionally, the UE shall:

[0188] a. If this message is received over 3GPP access and the value of the counter for the event "the current SNPN entry is considered invalid for 3GPP access" is less than a UE implementation specific maximum value, then for the case where the received 5GMM cause value is #3, proceed as specified in item A)-a of list in paragraph

[73] above (if the UE is operating in SNPN access mode);

[0189] b. If the message is received over non-3GPP access and the value of the counter for the event "the current SNPN entry is considered invalid for non-3GPP access" is less than a UE implementation specific maximum value, then for the case where the received 5GMM cause value is #3, proceed as specified in item A)-b of list in paragraph

[73] above (if the UE is operating in SNPN access mode);

[0190] c. Otherwise:

[0191] i. If a 5GMM cause value is received over 3GPP access, the UE shall:

[0192] 1. Set the update status for 3GPP access to 5U3 ROAMINGNOT ALLOWED, and only delete the stored 5G-

[0193] GUTI, TAI list, last visited registered TAI, and ngKSI.

[0194] The entry of the "User Data List" with the SNPN identification of the current SNPN shall be considered invalid for 3GPP access until the UE is switched off or the entry is reconfigured or removed.

[0195] ii. If a 5GMM cause value is received over non-3GPP access, the UE shall:

[0196] 1. Set the update status for non-3GPP access to 5U3 ROAMINGNOT ALLOWED, and only delete the stored 5G-GUTI, TAI list, last visited registered TAI and ngKSI for non-3GPP access.

[0197] The entry of the "User Data List" with the SNPN identification of the current SNPN shall be considered invalid for non-3GPP access until the UE is switched off or the entry is reconfigured or removed. The UE shall set the counter for the "entry with current SNPN considered invalid for non-3GPP access" event to a UE implementation specific maximum value.

[0198] In some embodiments, upon receiving the AUTHENTICATION REJECT message: a. If NAS has successfully performed an integrity check on the message, the UE shall set the update status to 5U3 ROAMING NOT ALLOWED and delete the stored 5G-

[0199] GUTI, TAI List, TAI of last visited registration and ngKSI. The entry of the "User Data List" with the SNPN identification of the current SNPN shall be considered invalid until the UE is switched off or the entry is reconfigured or removed.

[0200] i. The UE shall consider the entry for the current SNPN as invalid for 3GPP access

[0201] The counters for the event and the counter for the event "Current SNPN entry considered invalid for non-3GPP access" are set to UE implementation specific maximum values.

[0202] b. If this message is received without integrity protection, if the timer is not running, the UE shall start timer T3247 with a random value uniformly drawn from the range 30 minutes to 60 minutes. Additionally, the UE shall:

[0203] i. If this message is received over 3GPP access and the value of the counter for the event "the current SNPN entry is considered invalid for 3GPP access" is less than a UE implementation specific maximum value, then for the case where the received 5GMM cause value is #3, proceed as specified in item A)-a of paragraph

[73] above (if the UE

[0204] Operate in SNPN access mode);

[0205] ii. If the message is received via non-3GPP access and the value of the counter for the event "the entry for the current SNPN is considered invalid for non-3GPP access" is less than a UE implementation-specific maximum value, then for the case where the received 5GMM cause value is #3, proceed as specified in item A)-b of list in paragraph

[73] above (if the UE is operating in SNPN access mode).

[0206] iii. Otherwise:

[0207] If a 5GMM cause value is received over 3GPP access, the UE 102 shall:

[0208] a. Set the update status for 3GPP access to 5U3 ROAMING

[0209] NOT ALLOWED, for 3GPP access only delete the stored 5G-

[0210] GUTI, TAI List, last visited registered TAI and ngKSI. The entry of the "User Data List" with the SNPN identification of the current SNPN shall be considered invalid for 3GPP access until the UE is switched off or the entry is reconfigured or removed.

[0211] b. The UE shall set the counter for the event "the entry for the current SNPN is considered invalid for 3GPP access" to a UE implementation specific maximum value; and

[0212] If a 5GMM cause value is received over non-3GPP access, the UE shall:

[0213] a. Set the update status for non-3GPP access to 5U3 ROAMINGNOT ALLOWED, and only delete the stored 5G-

[0214] GUTI, TAI List, last visited registered TAI and ngKSI. The entry of the "User Data List" with the SNPN identification of the current SNPN shall be considered invalid until the UE is switched off or the entry is reconfigured or removed.

[0215] b. The UE shall set the counter for the event "the entry for the current SNPN is considered invalid for non-3GPP access" to a UE implementation specific maximum value.

[0216] While many of the embodiments described herein relate to 5G systems, it should be understood that other embodiments are also contemplated and are within the scope of the present disclosure, including or configured to operate in other system types such as 4G systems, etc.

[0217] Reference now Figure 5 , which provides a method 10 for handling a rejection message that is not integrity protected in a non-public network. The method 10 may be performed in part or in whole by a UE 102, an apparatus 202, or any other suitable component. In some embodiments, the method may include: at 11, in response to sending an initial registration request, receiving a registration rejection message from a network entity. The method 10 may further include: at 12, starting one or more timers, the one or more timers being configured to monitor the time that has passed since the registration rejection message was received. The method 10 may further include: at 13, randomly determining a duration value within a predetermined range between a minimum value and a maximum value, the minimum value corresponding to a minimum safety duration for sending a subsequent registration request to the network entity. The method 10 may further include: at 14, determining, via the one or more timers, whether the time that has passed since the registration rejection message was received corresponds to a randomly selected duration value. The method 10 may further include: at 15, in the case of determining that the time that has passed corresponds to the randomly selected duration value, sending the subsequent registration request to the network entity.

[0218] In some embodiments, the registration rejection message may include a reason code indicating why the network entity cannot register the device. In some embodiments, the method may further include: determining whether the registration rejection message is an integrity-protected message based at least on the reason code. In some embodiments, method 10 may further include: in the event that the registration rejection message is determined to be an integrity-protected message, immediately sending a subsequent registration request to the network entity. In some embodiments, the method may further include: sending an initial registration request to the network entity, the initial registration request including at least identification information for the user device. In some embodiments, one or more counters may be associated with entries of a user data list maintained by the device. In some embodiments, the one or more counters may include: a first counter associated with an entry of the user data list for a non-dedicated network to be considered for a network access event; and a second counter associated with an entry of the user data list for a dedicated network to be considered for a network access event.

[0219] In some embodiments, the user data list is a temporarily or permanently banned network list. In some embodiments, the method may further include: removing the entry of the user data list for the private network from the temporarily or permanently banned network list if the value of the second counter is greater than zero but less than the randomly selected duration value upon expiration of the second counter.

[0220] Reference now Figure 6 , which provides a method 20 for handling a rejection message that is not integrity protected in a non-public network. The method 20 may be performed in part or in whole by the UE 102, the apparatus 202, or any other suitable component. In some embodiments, the method 20 may include: at 21, receiving a registration rejection message from a network entity in response to sending an initial registration request. In some embodiments, the method 20 may further include: at 22, starting one or more timers, the one or more timers being configured to monitor the time elapsed since the registration rejection message was received, wherein the one or more counters are associated with an entry of a user data list maintained by the apparatus, the one or more counters including: a first counter associated with an entry of the user data list for a non-dedicated network considered for a network access event; and a second counter associated with an entry of the user data list for a dedicated network considered for a network access event. In some embodiments, the method 20 may further include: at 23, randomly determining a duration value within a predetermined range between a minimum value and a maximum value, the minimum value corresponding to a minimum safety duration for sending a subsequent registration request to the network entity. In some embodiments, the method 20 may further include: determining, via the one or more timers, whether the time elapsed since the registration rejection message was received corresponds to a randomly selected duration value at 24. In some embodiments, the method 20 may further include, in the event that the value of the second counter is greater than zero but less than the randomly selected duration value upon expiration of the second counter, removing the entry for the private network of the user data list from the temporary or permanent banned network list at 25. In some embodiments, the method 20 may further include: in the event that it is determined that the time elapsed corresponds to the randomly selected duration value, sending the subsequent registration request to the network entity at 26.

[0221] Reference now Figure 7, which provides a method 30 for handling a rejection message that is not integrity protected in a non-public network. The method 30 may be performed in part or in whole by the UE 102, the device 202, or any other suitable component. In some embodiments, the method 30 may include: at 31, receiving a rejection message from a network function in a standalone non-public network (SNPN), wherein the information in the rejection message indicates that the device is not allowed to access the SNPN through subscription. In some embodiments, the method 30 may further include: at 32, adding an identifier of the SNPN to a prohibited SNPN list associated with the access via which the device sent the request and subsequently received the rejection message. The method 30 may optionally further include: at 33, setting the 5GS update status to 5U3 ROAMING NOT ALLOWED, storing the 5GS update status; and deleting each of the 5G-GUTI, the last visited registered TAI, the TAI list, and the ngKSI. In some embodiments, the method 30 may optionally further include: at 34, upon determining that the elapsed time corresponds to a randomly selected duration value, sending the subsequent registration request to the network entity, and causing the apparatus to perform SNPN selection. In some embodiments, the method 30 may optionally further include: at 35, determining whether the NAS has successfully performed an integrity check on the rejection message; if the NAS has successfully performed an integrity check on the rejection message, setting an SNPN-specific attempt counter for non-3GPP access for the SNPN to a user equipment implementation-specific maximum value.

[0222] Reference now Figure 8 , which provides a method 40 for handling a rejection message that is not integrity protected in a non-public network. The method 40 may be performed in part or in whole by the UE 102, the device 202, or any other suitable component. In some embodiments, the method 40 may include: at 41, storing a list of user data, wherein each entry in the user data list includes user data for accessing a standalone non-public network (SNPN). In some embodiments, the method 40 may further include: at 42, maintaining one or more prohibited SNPN lists and one or more SNPN-specific attempt counters. In some embodiments, the method 40 may further include: at 43, in the event that an entry in the user data list is reconfigured or removed, based on the one or more SNPN-specific attempt counters, determining whether the identifier of the SNPN associated with the reconfigured or removed entry should be removed from the one or more prohibited SNPN lists.

[0223] Reference now Fig. 9, which provides a method 50 for handling a rejection message that is not integrity protected in a non-public network. The method 50 may be performed in part or in whole by the UE 102, the device 202, or any other suitable component. In some embodiments, the method 50 may include: at 51, storing a user data list, wherein each of the multiple entries in the user data list includes user data for accessing a standalone non-public network (SNPN). In an embodiment, the method 50 may further include: at 52, receiving a rejection message that is not integrity protected from a network function in the SNPN, wherein the information in the rejection message indicates that the entry for accessing the SNPN is invalid. In an embodiment, the method 50 may further include: at 53, upon receiving the rejection message, determining whether the entry for accessing the SNPN is invalid for the access via which the device sends a request message and / or receives the rejection message, and starting T3247. In some embodiments, method 50 may further include maintaining one or more counters for the SNPN at 54, wherein the one or more counters are used to determine whether an entry for accessing the SNPN should be set valid when T3247 expires.

[0224] As described herein, at least some embodiments of methods, apparatus, and computer program products are provided for handling non-integrity protected rejection messages in a non-public network.

[0225] In some example embodiments, an apparatus may be provided, comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus to at least: receive a rejection message from a network function in a standalone non-public network (SNPN), wherein information in the rejection message indicates that the apparatus is not allowed to access the SNPN through subscription; and add an identifier of the SNPN to a list of prohibited SNPNs, wherein the apparatus sends a request for access through subscription for the prohibited SNPN and subsequently receives the rejection message. In some embodiments, the information in the rejection message includes a 5GMM cause value #72, #74, or #75. In some embodiments, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to at least: set a 5GS update status to 5U3 ROAMING NOT ALLOWED; store the 5GS update status; and delete each of a 5G-GUTI, a last visited registered TAI, a TAI list, and an ngKSI. In some embodiments, at least one memory and computer program code are further configured to, together with at least one processor, cause the device to at least: cause the device to enter a 5GMM-DEREGISTERED state or a 5GMM-DEREGISTERED.PLMN-SEARCH state; and cause the device to perform SNPN selection. In some embodiments, at least one memory and computer program code are further configured to, together with at least one processor, cause the device to at least: determine whether NAS has successfully performed an integrity check on the rejection message; and if the NAS has successfully performed an integrity check on the rejection message, set the SNPN-specific attempt counter for non-3GPP access for SNPN to a user equipment-implemented specific maximum value. In some embodiments, the banned SNPN list is a permanently banned SNPN list. In some embodiments, the banned SNPN list is a temporarily banned SNPN list. In some embodiments, the banned SNPN list is a permanently banned SNPN list for non-3GPP access. In some embodiments, the banned SNPN list is a temporarily banned SNPN list for non-3GPP access.

[0226] In other example embodiments, a method, such as a computer-implemented method, may be provided, which may be implemented, for example, using an apparatus such as described herein. In some embodiments, the method may include: receiving a rejection message from a network function in a standalone non-public network (SNPN), wherein information in the rejection message indicates that the apparatus is not allowed to access the network through subscription; and adding an identification of the SNPN to a list of prohibited SNPNs, wherein the apparatus sends a request for access through subscription for the prohibited SNPN and subsequently receives the rejection message. In some embodiments, the information in the rejection message includes a 5GMM cause value #72, #74, or #75. In some embodiments, the method further includes: setting the 5GS update state to 5U3 ROAMING NOT ALLOWED; storing the 5GS update state; and deleting each of the 5G-GUTI, the last visited registered TAI, the TAI list, and the ngKSI. In some embodiments, the method further includes: causing the apparatus to enter a 5GMM-DEREGISTERED state or a 5GMM-DEREGISTERED.PLMN-SEARCH state; and causing the apparatus to perform SNPN selection. In some embodiments, the method further comprises: determining whether NAS has successfully performed an integrity check on the rejection message; and if NAS has successfully performed an integrity check on the rejection message, setting the SNPN-specific attempt counter for non-3GPP access for the SNPN to a user equipment-implemented specific maximum value. In some embodiments, the banned SNPN list is a permanently banned SNPN list. In some embodiments, the banned SNPN list is a temporarily banned SNPN list. In some embodiments, the banned SNPN list is a permanently banned SNPN list for non-3GPP access. In some embodiments, the banned SNPN list is a temporarily banned SNPN list for non-3GPP access.

[0227] In other example embodiments, an apparatus may be provided, such as an apparatus including at least one processor and at least one memory storing computer program code, which may be configured to implement a method such as described herein. In some embodiments, the apparatus may include: a component for receiving a rejection message from a network function in a standalone non-public network (SNPN), wherein the information in the rejection message indicates that the apparatus is not allowed to access the SNPN through subscription. In some embodiments, the apparatus may include a component for adding an identifier of the SNPN to a list of prohibited SNPNs, wherein the apparatus sends a request for access through subscription for the prohibited SNPN and subsequently receives the rejection message. In some embodiments, the information in the rejection message includes a 5GMM cause value #72, #74, or #75. In some embodiments, the apparatus may further include: a component for setting the 5GS update status to 5U3 ROAMING NOT ALLOWED; a component for storing the 5GS update status; and a component for deleting each of the 5G-GUTI, the last visited registered TAI, the TAI list, and the ngKSI. In some embodiments, the device may further include: a component for causing the device to enter a 5GMM-DEREGISTERED state or a 5GMM-DEREGISTERED.PLMN-SEARCH state; and a component for causing the device to perform SNPN selection. In some embodiments, the device may further include: a component for determining whether NAS has successfully performed an integrity check on the rejection message; and a component for setting the SNPN-specific attempt counter for non-3GPP access for SNPN to a specific maximum value achieved by the user equipment if NAS has successfully performed an integrity check on the rejection message. In some embodiments, the banned SNPN list is a permanently banned SNPN list. In some embodiments, the banned SNPN list is a temporarily banned SNPN list. In some embodiments, the banned SNPN list is a permanently banned SNPN list for non-3GPP access. In some embodiments, the banned SNPN list is a temporarily banned SNPN list for non-3GPP access.

[0228] In other example embodiments, a computer program product may be provided, such as a non-transitory computer-readable medium including program code, which when executed results in operations including: receiving a rejection message from a network function in a standalone non-public network (SNPN), wherein the information in the rejection message indicates that the device is not allowed to access the SNPN through subscription; and adding an identification of the SNPN to a list of prohibited SNPNs, wherein the device sends a request for access through subscription for the prohibited SNPN and subsequently receives the rejection message. In some embodiments, the information in the rejection message includes a 5GMM cause value #72, #74, or #75. In some embodiments, the program code results in further operations, which further operations include: setting the 5GS update status to 5U3 ROAMING NOT ALLOWED; storing the 5GS update status; and deleting each of the 5G-GUTI, the last visited registered TAI, the TAI list, and the ngKSI. In some embodiments, the program code causes further operations, which include: causing the device to enter a 5GMM-DEREGISTERED state or a 5GMM-DEREGISTERED.PLMN-SEARCH state; and causing the device to perform SNPN selection. In some embodiments, the program code causes further operations, which include: determining whether NAS has successfully performed an integrity check on the rejection message; and if NAS has successfully performed an integrity check on the rejection message, setting the SNPN-specific attempt counter for non-3GPP access for SNPN to a user equipment-implemented specific maximum value. In some embodiments, the banned SNPN list is a permanently banned SNPN list. In some embodiments, the banned SNPN list is a temporarily banned SNPN list. In some embodiments, the banned SNPN list is a permanently banned SNPN list for non-3GPP access. In some embodiments, the banned SNPN list is a temporarily banned SNPN list for non-3GPP access.

[0229] According to yet another embodiment, a device is provided, comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the device to at least: store a user data list, wherein each entry in the user data list comprises user data for accessing a standalone non-public network (SNPN); maintain one or more prohibited SNPN lists and one or more SNPN-specific attempt counters; and in the case where an entry in the user data list is reconfigured or removed, based on the one or more SNPN-specific attempt counters, determine whether the identification of the SNPN associated with the reconfigured or removed entry should be removed from the one or more prohibited SNPN lists. In some embodiments, the one or more prohibited SNPN lists comprise a permanently prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists comprise a temporarily prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists comprise a permanently prohibited SNPN list for non-3GPP access. In some embodiments, the one or more prohibited SNPN lists comprise a temporarily prohibited SNPN list for non-3GPP access. In some embodiments, the one or more SNPN-specific attempt counters comprise SNPN-specific attempt counters for 3GPP access. In some embodiments, the one or more SNPN-specific attempt counters include a SNPN-specific attempt counter for non-3GPP access.

[0230] According to yet another embodiment, a method is provided, the method comprising: storing a user data list, wherein each entry in the user data list comprises user data for accessing a standalone non-public network (SNPN); maintaining one or more prohibited SNPN lists and one or more SNPN-specific attempt counters; and determining whether the identification of the SNPN associated with the reconfigured or removed entry should be removed from the one or more prohibited SNPN lists based on the one or more SNPN-specific attempt counters in the event that an entry in the user data list is reconfigured or removed. In some embodiments, the one or more prohibited SNPN lists comprise a permanently prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists comprise a temporarily prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists comprise a permanently prohibited SNPN list for non-3GPP access. In some embodiments, the one or more prohibited SNPN lists comprise a temporarily prohibited SNPN list for non-3GPP access. In some embodiments, the one or more SNPN-specific attempt counters comprise an SNPN-specific attempt counter for 3GPP access. In some embodiments, the one or more SNPN-specific attempt counters comprise an SNPN-specific attempt counter for non-3GPP access.

[0231] According to another embodiment, a device is provided, such as a device including one or more processors and one or more memories storing computer program code. Such a device may be configured to perform any of the methods described herein, such as by using one or more processors to execute computer-implemented instructions stored on one or more memories. In some embodiments, the device may include: a component for storing a user data list, wherein each entry in the user data list includes user data for accessing a standalone non-public network (SNPN); a component for maintaining one or more prohibited SNPN lists and one or more SNPN-specific attempt counters; and a component for determining whether the identification of the SNPN associated with the reconfigured or removed entry should be removed from the one or more prohibited SNPN lists based on the one or more SNPN-specific attempt counters when the entry of the user data list is reconfigured or removed. In some embodiments, the one or more prohibited SNPN lists include a permanently prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists include a temporarily prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists include a permanently prohibited SNPN list for non-3GPP access. In some embodiments, the one or more prohibited SNPN lists include a temporarily prohibited SNPN list for non-3GPP access. In some embodiments, the one or more SNPN-specific attempt counters include a SNPN-specific attempt counter for 3GPP access. In some embodiments, the one or more SNPN-specific attempt counters include a SNPN-specific attempt counter for non-3GPP access.

[0232] In another example embodiment, a computer program product including a non-transitory computer-readable medium is provided, the non-transitory computer-readable medium including program code, which when executed causes operations, the operations including: storing a user data list, wherein each entry in the user data list includes user data for accessing a standalone non-public network (SNPN); maintaining one or more prohibited SNPN lists and one or more SNPN-specific attempt counters; and determining whether the identification of the SNPN associated with the reconfigured or removed entry should be removed from the one or more prohibited SNPN lists based on the one or more SNPN-specific attempt counters in the event that an entry in the user data list is reconfigured or removed. In some embodiments, the one or more prohibited SNPN lists include a permanent prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists include a temporary prohibited SNPN list. In some embodiments, the one or more prohibited SNPN lists include a permanent prohibited SNPN list for non-3GPP access. In some embodiments, the one or more prohibited SNPN lists include a temporary prohibited SNPN list for non-3GPP access. In some embodiments, the one or more SNPN-specific attempt counters include SNPN-specific attempt counters for 3GPP access. In some embodiments, the one or more SNPN-specific attempt counters include a SNPN-specific attempt counter for non-3GPP access.

[0233] According to another embodiment, a device is provided, the device including at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the device to at least: store a user data list, wherein each of a plurality of entries in the user data list includes user data for accessing a standalone non-public network (SNPN); receive a rejection message that is not integrity protected from a network function in the SNPN, wherein the information in the rejection message indicates that the entry for accessing the SNPN is invalid; upon receiving the rejection message, determine whether the entry for accessing the SNPN is invalid for the access via which the device sends a request message and / or receives the rejection message, and start T3247; and maintain one or more counters for the SNPN, wherein the one or more counters are used to determine whether the entry for accessing the SNPN should be set to valid when T3247 expires. In some embodiments, the information in the rejection message includes a 5GMM cause value #3 or #6. In some embodiments, the information in the rejection message includes an AUTHENITCATION REJECT message. In some embodiments, the rejection message is a REGISTRATION REJECT message or a SERVICE REJECT message. In some embodiments, the one or more counters include: a counter for events in which an entry for the current SNPN is considered invalid for 3GPP access; and a counter for events in which an entry for the current SNPN is considered invalid for non-3GPP access.

[0234] In yet another embodiment, a method is provided, the method comprising: storing a user data list, wherein each of a plurality of entries in the user data list comprises user data for accessing a standalone non-public network (SNPN); receiving a rejection message that is not integrity protected from a network function in the SNPN, wherein information in the rejection message indicates that the entry for accessing the SNPN is invalid; upon receiving the rejection message, determining whether the entry for accessing the SNPN is invalid for the access via which the device sends a request message and / or receives the rejection message, and starting T3247; and maintaining one or more counters for the SNPN, wherein the one or more counters are used to determine whether the entry for accessing the SNPN should be set to valid when T3247 expires. In some embodiments, the information in the rejection message comprises a 5GMM cause value #3 or #6. In some embodiments, the information in the rejection message comprises an AUTHENITCATION REJECT message. In some embodiments, the rejection message is a REGISTRATION REJECT message or a SERVICE REJECT message. In some embodiments, the one or more counters include: a counter for events where an entry for a current SNPN is considered invalid for 3GPP access; and a counter for events where an entry for a current SNPN is considered invalid for non-3GPP access.

[0235] According to another embodiment, a device is provided, such as a device including one or more processors and one or more memories storing computer program code. Such a device may be configured to perform any of the methods described herein, such as by using one or more processors to execute computer-implemented instructions stored on one or more memories. In some embodiments, the device may include: a component for storing a user data list, wherein each of a plurality of entries in the user data list includes user data for accessing a standalone non-public network (SNPN); a component for receiving a rejection message that is not integrity protected from a network function in the SNPN, wherein the information in the rejection message indicates that the entry for accessing the SNPN is invalid; a component for determining, upon receiving the rejection message, whether the entry for accessing the SNPN is invalid for the access via which the device sends a request message and / or receives the rejection message, and starting T3247; and a component for maintaining one or more counters for the SNPN, wherein the one or more counters are used to determine whether the entry for accessing the SNPN should be set to valid when T3247 expires. In some embodiments, the information in the rejection message includes a 5GMM cause value #3 or #6. In some embodiments, the information in the rejection message includes an AUTHENITCATION REJECT message. In some embodiments, the rejection message is a REGISTRATION REJECT message or a SERVICE REJECT message. In some embodiments, the one or more counters include: a counter for events in which an entry for the current SNPN is considered invalid for 3GPP access; and a counter for events in which an entry for the current SNPN is considered invalid for non-3GPP access.

[0236] According to another embodiment, a computer program product including a non-transitory computer-readable medium is provided, the non-transitory computer-readable medium including program code, which when executed causes operations, the operations including: storing a user data list, wherein each of a plurality of entries in the user data list includes user data for accessing a standalone non-public network (SNPN); receiving a rejection message that is not integrity protected from a network function in the SNPN, wherein the information in the rejection message indicates that the entry for accessing the SNPN is invalid; upon receiving the rejection message, determining whether the entry for accessing the SNPN is invalid for the access via which the device sends a request message and / or receives the rejection message, and starting T3247; and maintaining one or more counters for the SNPN, wherein the one or more counters are used to determine whether the entry for accessing the SNPN should be set to valid when T3247 expires. In some embodiments, the information in the rejection message includes a 5GMM cause value #3 or #6. In some embodiments, the information in the rejection message includes an AUTHENITCATION REJECT message. In some embodiments, the rejection message is a REGISTRATION REJECT message or a SERVICE REJECT message.In some embodiments, the one or more counters include: a counter for events where an entry for the current SNPN is considered invalid for 3GPP access; and a counter for events where an entry for the current SNPN is considered invalid for non-3GPP access.

[0237] According to another example embodiment, an apparatus is provided, the apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus to at least: receive a rejection message from a network function in a standalone non-public network (SNPN); start one or more timers, the one or more timers being configured to monitor the time elapsed since the rejection message was received; randomly determine a duration value within a predetermined range between a minimum value and a maximum value, the minimum value corresponding to a minimum safe duration for sending a subsequent registration request to the network function; via the one or more timers, determine whether the time elapsed since the rejection message was received corresponds to the randomly selected duration value; and if it is determined that the elapsed time corresponds to the randomly selected duration value, send the subsequent registration request to the network entity. In some embodiments, the registration rejection message includes a reason code indicating the reason why the network entity cannot register the apparatus. In some embodiments, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to at least: determine whether the registration rejection message is an integrity protected message based at least on the reason code. In some embodiments, at least one memory and computer program code are further configured to, with at least one processor, cause the apparatus to at least: immediately send a subsequent registration request to a network entity if the registration rejection message is determined to be an integrity protected message. In some embodiments, at least one memory and computer program code are further configured to, with at least one processor, cause the apparatus to at least: send an initial registration request to a network entity, the initial registration request comprising at least identification information for a user device. In some embodiments, one or more counters are associated with entries of a user data list maintained by the apparatus, the one or more counters comprising: a first counter associated with an entry of the user data list for a non-dedicated network considered for a network access event; and a second counter associated with an entry of the user data list for a dedicated network considered for a network access event. In some embodiments, the user data list is a temporary or permanent banned network list, wherein at least one memory and computer program code are further configured to, with at least one processor, cause the apparatus to at least: remove the entry of the user data list for a dedicated network from the temporary or permanent banned network list if the value of the second counter is greater than zero but less than a randomly selected duration value upon expiration of the second counter.

[0238] According to yet another embodiment, a method is provided, the method comprising: receiving a registration rejection message from a network entity in response to sending an initial registration request; starting one or more timers, the one or more timers being configured to monitor the time elapsed since the registration rejection message was received; randomly determining a duration value within a predetermined range between a minimum value and a maximum value, the minimum value corresponding to a minimum safe duration for sending a subsequent registration request to the network entity; determining, via the one or more timers, whether the time elapsed since the registration rejection message was received corresponds to the randomly selected duration value; and sending the subsequent registration request to the network entity if it is determined that the elapsed time corresponds to the randomly selected duration value. In some embodiments, the registration rejection message includes a reason code indicating why the network entity cannot register the device. In some embodiments, the method further comprises: determining, based at least on the reason code, whether the registration rejection message is an integrity protected message. In some embodiments, the method further comprises: immediately sending a subsequent registration request to the network entity if the registration rejection message is determined to be an integrity protected message. In some embodiments, the method further comprises: sending the initial registration request to the network entity, the initial registration request including at least identification information for the user equipment. In some embodiments, one or more counters are associated with an entry of a user data list maintained by the device, the one or more counters comprising: a first counter associated with an entry of the user data list for a non-dedicated network being considered for a network access event; and a second counter associated with an entry of the user data list for a dedicated network being considered for a network access event. In some embodiments, the user data list is a temporary or permanent banned network list, the method further comprising: removing the entry of the user data list for the dedicated network from the temporary or permanent banned network list if the value of the second counter is greater than zero but less than a randomly selected duration value upon expiration of the second counter.

[0239] According to another embodiment, an apparatus is provided, such as an apparatus including one or more processors and one or more memories storing computer program code. Such an apparatus may be configured to perform any of the methods described herein, such as by using one or more processors to execute computer-implemented instructions stored on one or more memories. In some embodiments, the apparatus may include: a component for receiving a registration rejection message from a network entity in response to sending an initial registration request; a component for starting one or more timers, wherein the one or more timers are configured to monitor the time elapsed since the registration rejection message was received; a component for randomly determining a duration value within a predetermined range between a minimum value and a maximum value, wherein the minimum value corresponds to a minimum safe duration for sending subsequent registration requests to the network entity; a component for determining, based on the one or more timers, whether the time elapsed since the registration rejection message was received corresponds to a randomly selected duration value; and a component for sending the subsequent registration request to the network entity if it is determined that the elapsed time corresponds to the randomly selected duration value. In some embodiments, the registration rejection message includes a reason code indicating the reason why the network entity cannot register the device. In some embodiments, the apparatus further includes: a component for determining whether the registration rejection message is an integrity protected message based at least on the reason code. In some embodiments, the apparatus further comprises: a component for immediately sending a subsequent registration request to the network entity if the registration rejection message is determined to be an integrity protected message. In some embodiments, the apparatus further comprises: a component for sending an initial registration request to the network entity, wherein the initial registration request comprises at least identification information for the user equipment. In some embodiments, one or more counters are associated with entries of a user data list maintained by the apparatus, the one or more counters comprising: a first counter associated with an entry of the user data list for a non-dedicated network considered for a network access event; and a second counter associated with an entry of the user data list for a dedicated network considered for a network access event. In some embodiments, the user data list is a temporary or permanent banned network list, and the apparatus further comprises: a component for removing the entry of the user data list for the dedicated network from the temporary or permanent banned network list if the value of the second counter is greater than zero but less than a randomly selected duration value upon expiration of the second counter.

[0240] According to yet another embodiment, a computer program product is provided that includes a non-transitory computer-readable medium that includes program code that, when executed, results in operations that include: receiving a registration rejection message from a network entity in response to sending an initial registration request; starting one or more timers configured to monitor the time that has passed since the registration rejection message was received; randomly determining a duration value within a predetermined range between a minimum value and a maximum value, the minimum value corresponding to a minimum safe duration for sending a subsequent registration request to the network entity; based on the one or more timers, determining whether the time that has passed since the registration rejection message was received corresponds to the randomly selected duration value; and if it is determined that the time that has passed corresponds to the randomly selected duration value, sending the subsequent registration request to the network entity. In some embodiments, the registration rejection message includes a reason code indicating why the network entity cannot register the device. In some embodiments, the program code results in further operations that include: determining, based at least on the reason code, whether the registration rejection message is an integrity-protected message. In some embodiments, the program code results in further operations that include: if the registration rejection message is determined to be an integrity-protected message, immediately sending a subsequent registration request to the network entity. In some embodiments, the program code causes further operations, the further operations comprising: sending an initial registration request to a network entity, the initial registration request comprising at least identification information for the user equipment. In some embodiments, one or more counters are associated with entries of a user data list maintained by the apparatus, the one or more counters comprising: a first counter associated with an entry of the user data list for a non-dedicated network being considered for a network access event; and a second counter associated with an entry of the user data list for a dedicated network being considered for a network access event. In some embodiments, the user data list is a list of temporarily or permanently banned networks, the program code causes further operations, the further operations comprising: removing the entry of the user data list for the dedicated network from the list of temporarily or permanently banned networks if the value of the second counter is greater than zero but less than a randomly selected duration value upon expiration of the second counter.

[0241] The above aspects and features can be implemented in systems, devices, methods and / or products according to the desired configuration. The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the detailed description. The features and advantages of the subject matter described herein will become apparent from the description and drawings and from the claims.

[0242] The subject matter disclosed herein can be embodied in a system, device, method and / or product according to the desired configuration. For example, the base station and user equipment (or one or more components thereof) and / or the process described herein can be implemented using one or more of the following: a processor that executes program code, an application-specific integrated circuit (ASIC), a digital signal processor (DSP), an embedded processor, a field programmable gate array (FPGA), and / or a combination thereof. These various implementations may include implementations in one or more computer programs, wherein these computer programs may be executed and / or interpreted on a programmable system including at least one programmable processor, at least one input device and at least one output device, and the programmable processor may be dedicated or general-purpose for receiving / sending data and instructions from / to a storage system. These computer programs (also referred to as programs, software, software applications, applications, components, program codes or codes) may include machine instructions for programmable processors and may be implemented using high-level programs, and / or object-oriented programming languages, and / or assembly / machine languages. As used herein, the term "computer-readable medium" refers to any computer program product, computer-readable medium, machine-readable medium, computer-readable storage medium, means and / or device (e.g., disk, optical disk, memory, programmable logic device (PLD)) for providing machine instructions and / or data to a programmable processor (including a machine-readable medium that receives machine instructions). Similarly, the systems also described herein may include a processor and a memory coupled to the processor. The memory may include one or more programs that cause the processor to perform one or more of the operations described herein.

[0243] Although some variations have been described in detail above, other modifications or additions may also be made. In particular, further features and / or variations may be provided in addition to those set forth herein. Furthermore, implementations as described above may be for various combinations and subcombinations of the disclosed features and / or combinations and subcombinations of some further features disclosed above. Other embodiments may fall within the scope of the appended claims.

[0244] If desired, the different functions discussed herein may be performed in different orders and / or simultaneously with each other. In addition, if desired, one or more of the above functions may be optional or may be combined. Although various aspects of some embodiments are set forth in the independent claims, other aspects of some embodiments include other combinations of features from the described embodiments and / or dependent claims with features of the independent claims, rather than just the combinations explicitly listed in the claims. It should also be noted herein that although example embodiments are described above, these descriptions should not be considered restrictive. On the contrary, several changes and modifications may be made without departing from the scope of some embodiments as defined in the appended claims. Other embodiments may fall within the scope of the appended claims. The term "based on" includes "at least based on". Unless otherwise specified, the phrase "such as" is used to mean "such as, for example".

[0245] It should be understood that the term "user equipment" is intended to cover any suitable type of wireless user equipment, such as a mobile phone, a portable data processing device, or a portable web browser. It should also be understood that the term "user equipment" is intended to cover any suitable type of non-portable user equipment, such as a television receiver, a desktop data processing device, or a set-top box.

[0246] In general, various embodiments of the present invention 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 that may be executed by a controller, microprocessor, or other computing device, but the present invention is not limited thereto. Although various aspects of the present invention may be illustrated and described as block diagrams, flow charts, or using some other graphical representation, it should be well understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented using hardware, software, firmware, dedicated circuits or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0247] Embodiments of the present invention can be implemented by computer software that can be executed by a data processor of a mobile device (such as in a processor entity), or by hardware, or by a combination of software and hardware. In addition, in this regard, it should be noted that any box of the logic flow as in the accompanying drawings can represent a program step, or an interconnected logic circuit, box and function, or a combination of a program step and a logic circuit, box and function. The software can be stored on a physical medium, such as a memory chip, or a memory block implemented in a processor, a magnetic medium such as a hard disk or a floppy disk, and an optical medium such as a DVD and its data variant CD. The memory can be any type suitable for a local technical environment and can be implemented using any suitable data storage technology, such as a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, a fixed memory and a removable memory. The data processor can be any type suitable for a local technical environment, and as a non-limiting example, it can include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP) and a processor based on a multi-core processor architecture.

[0248] The foregoing description has provided a complete and exhaustive description of exemplary embodiments of the present invention by way of exemplary and non-limiting examples. However, various modifications and adaptations may become apparent to those skilled in the relevant art in view of the foregoing description when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of the present invention will still fall within the scope of the present invention.

Claims

1. A device (202), comprising: at least one processor (204); as well as at least one memory (206) storing instructions that, when executed by the at least one processor, cause the apparatus to at least: storing (41) a subscriber data list, wherein each entry in the subscriber data list comprises subscriber data for accessing a SNPN identified by a separate non-public network SNPN identification included in the entry; maintaining (42) one or more prohibited SNPN lists; maintaining one or more SNPN specific attempt counters for each entry in the subscriber data list; maintaining, for each entry in the subscriber data list, one or more event counters for events in which the respective entry is deemed invalid for access; receiving a non-integrity-protected rejection message from a network function in the SNPN, the non-integrity-protected rejection message comprising information suggesting that an entry comprising the subscriber data for accessing the SNPN is invalid; Upon receiving the non-integrity-protected rejection message, starting a timer; upon expiration of the timer, determining based on the one or more event counters for the SNPN whether the entry comprising the subscriber data for accessing the SNPN should be set valid; as well as In the event that an entry in the subscriber data list is reconfigured or removed, determining (43) based on the one or more SNPN-specific attempt counters whether the SNPN identifier in the reconfigured or removed entry should be removed from the one or more prohibited SNPN lists.

2. A device as described in claim 1, wherein the one or more prohibited SNPN lists include one or more of the following: a permanently prohibited SNPN list, a temporarily prohibited SNPN list, a permanently prohibited SNPN list for non-third generation partnership project - non-3GPP - access, or a temporarily prohibited SNPN list for non-3GPP access.

3. The device of claim 1, wherein the one or more SNPN specific attempt counters include one or more of: a SNPN specific attempt counter for a 3rd Generation Partnership Project 3GPP access, or a SNPN specific attempt counter for a non-3GPP access.

4. The device of claim 1, wherein the one or more event counters for events in which the corresponding entry is considered invalid include one or more of: an event counter for events in which the corresponding entry is considered invalid for 3GPP access, and an event counter for events in which the corresponding entry is considered invalid for non-3GPP access.

5. The apparatus of claim 1 , wherein upon expiration of the timer, the entry comprising the subscriber data for accessing the SNPN is set to valid based on determining that the one or more event counters for the SNPN have a value less than a UE implementation specific value.

6. An apparatus as claimed in claim 1, wherein in a case where an entry in the subscriber data list is reconfigured or removed, it is determined that the SNPN identifier in the reconfigured or removed entry is removed from the one or more prohibited SNPN lists based on determining that the one or more SNPN-specific attempt counters for the SNPN have a value greater than zero and less than a UE-implemented specific maximum value and that the SNPN identifier is in any one of the one or more prohibited SNPN lists.

7. The apparatus of claim 1, wherein the timer is a 3rd Generation Partnership Project (3GPP) timer T3247.

8. A method comprising: storing (41) a subscriber data list, wherein each entry in the subscriber data list comprises subscriber data for accessing a SNPN identified by a separate non-public network SNPN identification included in the entry; maintaining (42) one or more prohibited SNPN lists; maintaining one or more SNPN specific attempt counters for each entry in the subscriber data list; maintaining, for each entry in the subscriber data list, one or more event counters for events in which the respective entry is deemed invalid for access; receiving a non-integrity-protected rejection message from a network function in the SNPN, the non-integrity-protected rejection message comprising information suggesting that an entry comprising the subscriber data for accessing the SNPN is invalid; Upon receiving the non-integrity-protected rejection message, starting a timer; upon expiration of the timer, determining based on the one or more event counters for the SNPN whether the entry comprising the subscriber data for accessing the SNPN should be set valid; as well as In the event that an entry in the subscriber data list is reconfigured or removed, determining (43) based on the one or more SNPN-specific attempt counters whether the SNPN identifier in the reconfigured or removed entry should be removed from the one or more prohibited SNPN lists.

9. A method as claimed in claim 8, wherein the one or more prohibited SNPN lists include one or more of the following: a permanently prohibited SNPN list, a temporarily prohibited SNPN list, a permanently prohibited SNPN list for non-third generation partnership project - non-3GPP - access, or a temporarily prohibited SNPN list for non-3GPP access.

10. The method of claim 8, wherein the one or more SNPN specific attempt counters include one or more of: a SNPN specific attempt counter for 3GPP access, or a SNPN specific attempt counter for non-3GPP access.

11. The method of claim 8, wherein the one or more event counters for events in which the corresponding entry is considered invalid include one or more of the following: an event counter for events in which the corresponding entry is considered invalid for 3GPP access, and an event counter for events in which the corresponding entry is considered invalid for non-3GPP access.

12. The method of claim 8, wherein upon expiration of the timer, determining to set the entry including the subscriber data for accessing the SNPN to be valid is based on determining that the one or more event counters for the SNPN have a value less than a UE implementation specific value.

13. A method as claimed in claim 8, wherein in a case where an entry in the subscriber data list is reconfigured or removed, it is determined that the SNPN identifier in the reconfigured or removed entry is removed from the one or more prohibited SNPN lists based on determining that the one or more SNPN-specific attempt counters for the SNPN have a value greater than zero and less than a UE-implemented specific maximum value and that the SNPN identifier is in any one of the one or more prohibited SNPN lists.

14. The method of claim 8, wherein the timer is a 3rd Generation Partnership Project (3GPP) timer T3247.

15. A computer-readable medium comprising instructions that, when executed by a device, cause the device to at least: storing (41) a subscriber data list, wherein each entry in the subscriber data list comprises subscriber data for accessing a SNPN identified by a separate non-public network SNPN identification included in the entry; maintaining (42) one or more prohibited SNPN lists; maintaining one or more SNPN specific attempt counters for each entry in the subscriber data list; maintaining, for each entry in the subscriber data list, one or more event counters for events in which the respective entry is deemed invalid for access; receiving a non-integrity-protected rejection message from a network function in the SNPN, the non-integrity-protected rejection message comprising information suggesting that an entry comprising the subscriber data for accessing the SNPN is invalid; Upon receiving the non-integrity-protected rejection message, starting a timer; upon expiration of the timer, determining based on the one or more event counters for the SNPN whether the entry comprising the subscriber data for accessing the SNPN should be set valid; as well as In the event that an entry in the subscriber data list is reconfigured or removed, determining (43) based on the one or more SNPN-specific attempt counters whether the SNPN identifier in the reconfigured or removed entry should be removed from the one or more prohibited SNPN lists.

16. A computer-readable medium as described in claim 15, wherein the one or more prohibited SNPN lists include one or more of the following: a permanently prohibited SNPN list, a temporarily prohibited SNPN list, a permanently prohibited SNPN list for non-third generation partnership project - non-3GPP - access, or a temporarily prohibited SNPN list for non-3GPP access.

17. The computer-readable medium of claim 15, wherein the one or more SNPN-specific attempt counters comprise one or more of: an SNPN-specific attempt counter for a 3rd Generation Partnership Project (3GPP) access, or an SNPN-specific attempt counter for a non-3GPP access.

18. A computer-readable medium as described in claim 15, wherein the one or more event counters for events in which the corresponding entry is considered invalid include one or more of the following: an event counter for events in which the corresponding entry is considered invalid for 3GPP access, and an event counter for events in which the corresponding entry is considered invalid for non-3GPP access.

19. The computer-readable medium of claim 15, wherein upon expiration of the timer, the entry comprising the subscriber data for accessing the SNPN is set to valid based on a determination that the one or more event counters for the SNPN have a value less than a UE implementation specific value.

20. A computer-readable medium as described in claim 15, wherein in a case where an entry in the subscriber data list is reconfigured or removed, it is determined that the SNPN identifier in the reconfigured or removed entry is removed from the one or more prohibited SNPN lists based on determining that the one or more SNPN-specific attempt counters for the SNPN have a value greater than zero and less than a UE-implemented specific maximum value and that the SNPN identifier is in any one of the one or more prohibited SNPN lists.

21. The non-transitory computer readable medium of claim 15, wherein the timer is a 3rd Generation Partnership Project (3GPP) timer T3247.

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