Optimize the use of PDU session state in IE

Abstract

This document discloses systems and methods for managing the synchronization of Protocol Data Unit (PDU) sessions between a User Equipment (UE) and a network. In some embodiments, determining whether a message including a PDU session state information element (IE) should be sent is based on previous messaging between peer entities of the network. In some embodiments, a determination is made to inform the peer entity of the relevant PDU session state after receiving an expected reply message in response to a previous messaging. In some cases, when it is determined that each entity has a matching PDU session state, a reply message without a PDU session state IE is sent from one entity to the peer entity. Situations involving faults detected at the network and cases where an entity activates a Data Radio Bearer (DRB) for a PDU session that is inactive at its peer are also discussed.

Description

Technical Field

[0001] This application relates in its entirety to wireless communication systems, including wireless communication systems that use messages containing Protocol Data Unit (PDU) Session State Information Elements (IEs) to maintain PDU session synchronization between a User Equipment (UE) and a network. Background Technology

[0002] Wireless mobile communication technologies use various standards and protocols to transmit data between base stations and wireless mobile devices. Wireless communication system standards and protocols may include 3GPP Long Term Evolution (LTE) (e.g., 4G) or New Radio (NR) (e.g., 5G); the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard, commonly referred to by the industry organization as WiMAX; and the IEEE 802.11 standard for Wireless Local Area Networks (WLANs), commonly referred to by the industry organization as Wi-Fi. In the 3GPP Radio Access Network (RAN) of an LTE system, a base station may include RAN nodes such as an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly referred to as Evolved Node B, Enhanced Node B, eNodeB, or eNB) and / or a Radio Network Controller (RNC) in the E-UTRAN, which communicates with wireless communication equipment called User Equipment (UE). In the fifth generation (5G) wireless RAN, RAN nodes may include 5G nodes and NR nodes (also known as next-generation node B or g NodeB (gNB)).

[0003] The RAN uses Radio Access Technology (RAT) to communicate between RAN nodes and UEs. The RAN may include Global System for Mobile Communications (GSM), Enhanced Data Rate GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), and / or E-UTRAN, which provides access to communication services through the core network. Each RAN operates according to a specific 3GPP RAT. For example, GERAN implements the GSM and / or EDGE RAT, UTRAN implements the Universal System for Mobile Communications (UMTS) RAT or other 3GPP RATs, E-UTRAN implements the LTE RAT, and NG-RAN implements the 5G RAT. In some deployments, E-UTRAN may also implement the 5G RAT.

[0004] 5G NR frequency bands can be divided into two distinct frequency ranges. Frequency range 1 (FR1) may include bands operating below 6 GHz, some of which are available for previous standards and can potentially be extended to cover new spectrum offerings from 410 MHz to 7125 MHz. Frequency range 2 (FR2) may include bands from 24.25 GHz to 52.6 GHz. Bands in the millimeter wave (mmWave) range of FR2 may have smaller coverage areas but potentially higher available bandwidth than those in FR1. Those skilled in the art will recognize that these frequency ranges, presented by way of example, may vary over time or in different regions. Attached Figure Description

[0005] To facilitate identification of any particular element or action being discussed, one or more of the most significant digits in the reference numerals refer to the drawing number in which the element was first introduced.

[0006] Figure 1 A method for a UE according to an implementation scheme is shown.

[0007] Figure 2 A method for a UE according to an implementation scheme is shown.

[0008] Figure 3 A method for a UE according to an implementation scheme is shown.

[0009] Figure 4 A method for a UE according to an implementation scheme is shown.

[0010] Figure 5 A method for a UE according to an implementation scheme is shown.

[0011] Figure 6 A method for AMF of a network according to an implementation scheme is shown.

[0012] Figure 7 A method for a UE according to an implementation scheme is shown.

[0013] Figure 8 A method for AMF of a network according to an implementation scheme is shown.

[0014] Figure 9 A method for a UE according to an implementation scheme is shown.

[0015] Figure 10 A method for a UE according to an implementation scheme is shown.

[0016] Figure 11 A UE according to one implementation is shown.

[0017] Figure 12 A network node according to one implementation scheme is shown.

[0018] Figure 13 An example of a service-based architecture according to certain implementation schemes is shown.

[0019] Figure 14 The components according to one implementation are shown. Detailed Implementation

[0020] User equipment (UE) and the network can communicate with each other using one or more Protocol Data Unit (PDU) sessions. A PDU session can be understood as including a logical connection between the UE and the network (e.g., a Data Radio Bearer (DRB)). Such PDU sessions provide data transmission for communication outside the network. In other words, the UE can communicate with external entities using one or more PDUs connected to the network. A PDU session can be established according to the protocol used to transmit data to the external entity. For example, a PDU session can be entered for use based on IP packets, Ethernet frames, or some other type of transport arrangement. In some RATs (e.g., NR), multiple simultaneous PDU sessions between the UE and the network can be considered. These PDU sessions may include one or more active PDU sessions. An active PDU session can be a PDU session that maintains its context at the relevant system entity (e.g., the UE and / or the network) and may correspond to a DRB. The DRB of an active PDU session can itself be in an active, suspended, or inactive state. Other PDU sessions among these PDU sessions that are considered to be between the UE and the network can be considered inactive PDU sessions, where no DRB has been established and no PDU session context exists at the relevant system entity (e.g., the UE and / or the network).

[0021] In order to use a PDU session to transmit data, the PDU session must be active on both the UE side and the network side (e.g., at the network's Access and Mobility Management Function (AMF) and Session Management Function (SMF)). Therefore, it may be useful for an entity of the wireless communication system to track the current PDU sessions that are currently active at that entity, and it may be further useful for this entity to pass this information to another peer entity of the wireless communication system (e.g., from the UE to the network's AMF or vice versa).

[0022] One way an entity transmits this information to its peer is by sending a PDU session state information element (IE), which describes the PDU session state of the sending entity (e.g., an indication of which PDU sessions are active and / or inactive at the sending entity). In some instances, the PDU session state IE may be sent, for example, in a service request message from the UE to the network. A service request may be a message used by the UE to move to a connection mode with the network and establish a new PDU session. The service request may also be used to establish a DRB for a PDU session and / or reactivate a pending DRB for an established PDU session between the UE and the network. The service request message may be a service request procedure message, as defined in TS 23.502 (September 2020) (see section 4.2.3 for general information). The PDU session state IE in such a service request message reports to the network the PDU sessions that are active at the UE, allowing the network to determine which PDU conversations are active at the UE. Furthermore, in some of these cases, the network may respond to a service request message with a service accept message or service reject message, including a PDU session state IE. This PDU session state IE reports to the UE the PDU sessions that are active at the network, allowing the UE to determine which PDU sessions are active on the network. In some of these cases, this allows the UE to determine which PDU sessions should remain active at the UE and to locally release those PDU sessions that are not active at the network. In this way, both the UE and the network synchronize the context of the PDU sessions.

[0023] In other instances, the PDU session state IE can be sent from the UE to the network in a registration request message. The registration request message can be a registration procedure message, as defined in TS 23.502 (September 2020) (generally see section 4.2.2). The registration request message can also be a message used by the UE to attach or update the UE's location or other configuration changes to the network, as described in TS 24.501 (sections 5.5.1.2 and 5.5.1.3). The PDU session state IE in such a registration request message reports to the network the PDU session that is active at the UE, allowing the network to activate the same PDU session. Furthermore, in some of these cases, the network can respond to the registration request message with a registration accept message that includes the PDU session state IE, which reports to the UE the PDU session that is active at the network, allowing the UE to ensure that it is indeed synchronized with the network.

[0024] Such PDU session states (IEs) can be used to resolve PDU session desynchronization (e.g., resolving the issue of the UE and network not having the same understanding regarding which PDU sessions are active at another entity). For example, desynchronization between the UE and the network may occur due to radio link failure (RLF) when the PDU session release procedure is in progress, or when the UE or network releases the PDU session locally, when the UE cannot reach the network, or when the UE cannot establish a connection with the network.

[0025] In one instance of this situation, the UE might have already locally deactivated its PDU session and attempted to send a PDU session release request message to the network indicating that this had occurred. However, if an RLF (Resolved Level Failure) occurs between the UE and the network close to this point, the network may never have successfully received the PDU session release request message. Therefore, the network is unaware that the UE has locally deactivated its PDU session and does not correspondingly deactivate it locally. In other words, the UE and the network are now out of PDU session synchronization. Subsequent transmissions of messages from the UE to the network, including the PDU session state IE (e.g., once the RLF condition is resolved), can instead be used to notify the network that the UE has deactivated its PDU session, thereby allowing the UE and the network to resynchronize the active PDU session.

[0026] Another similar situation that could lead to desynchronization could occur when an RLF (Regression-Range Function Failure) occurs when the network (e.g., the AMF) attempts to indicate the PDU session state to the UE (e.g., acknowledgment or change). In a similar manner, subsequent transmissions of messages from the network to the UE including the PDU session state IE (e.g., once the RLF condition is resolved) could instead be used to inform the UE of the acknowledgment and / or change, thereby allowing the network and UE to resynchronize their active PDU sessions.

[0027] The transmission of one or more PDU session state IEs can be resource-intensive. For example, in some wireless communication systems, sending a PDU session state IE in a service request message or registration request message may use up to four bytes of information in each such message. Furthermore, a reply in a service accept message or registration accept message from the network may also use up to four bytes of information in each such message. Additionally, when the PDU session state IE is a non-plaintext IE (e.g., when the UE has a valid security context), the PDU session state IE can be encrypted (using power and time), after which it can be as large as 16 bytes (using additional transmission resources). Furthermore, in some wireless communication systems, the UE may frequently send service request messages, as this may be the best way to enter connected mode and establish a bearer for an established PDU session. Moreover, when the UE is in idle mode, service accept messages may be frequently used when sending Short Message Service (SMS) messages, Location Service (LCS) signaling, LTE Location Protocol (LPP) signaling, or Session Management (SM) signaling messages.

[0028] Therefore, such wireless communication systems can be further optimized by identifying when messages (such as service request messages, service acceptance messages, registration request messages, and / or registration acceptance messages) need (or do not need) to include the PDU session state IE (e.g., to help ensure PDU session synchronization), and by configuring elements of the wireless communication system (e.g., the UE, the network's AMF, etc.) to function in situations where not every such message includes the PDU session state IE (e.g., to save resources within the wireless communication system where possible).

[0029] In some cases, it may be preferable to send a service request message instead of another possible message (such as a registration request message). This is likely because using a service request message may consume fewer resources than using other messages. Therefore, wireless communication systems can be further optimized by being configured to use service acceptance messages instead of other message options when possible.

[0030] Receiving a Mobile Station Called (MT) paging or notification request from the network at the UE may be a situation where the UE can be configured to respond (or not respond) with a PDU session state IE. Whether to respond can be determined based on other recent communications with the network. For example, if the UE determines that it has locally deactivated (or is deactivating) a PDU session, and it has not yet (and has not yet been) able to initiate a registration request message to the network reporting this deactivation (or ongoing deactivation), the UE can indicate that this PDU session is no longer active by placing the corresponding PDU session state IE indicating this information in the service request message or registration request message responding to the MT paging or notification request. The network can then respond appropriately to the PDU session state IE. For example, the AMF can release the PDU session corresponding to the deactivated (and / or ongoing deactivation) at the UE by communicating with the SMF. Furthermore, the AMF can instruct the base station to release any DRBs associated with such PDU sessions.

[0031] In other cases, the UE may receive MT paging or notification requests from the network and respond to the network using service requests or registration requests without indicating that one or more PDU sessions are deactivated in the PDU session state IE. In these cases, upon the termination of the corresponding service request procedure or registration request procedure, the UE may immediately follow up with a PDU session release request message for each PDU session in one or more PDU sessions (if the PDU session has not yet been completed due to, for example, RLF).

[0032] In other cases, if the UE determines that it has (already) sent a registration request message reporting local deactivation of the PDU session before receiving an MT paging or notification request, the UE may omit the PDU session state IE in the service request message or registration request message (if applicable) in response to the MT paging or notification request.

[0033] Figure 1 A method 100 for a UE according to an implementation scheme is shown. Method 100 includes receiving one of a notification request message 102 from the network and an MT paging.

[0034] Method 100 also includes determining 104 that a PDU session previously available at the UE is no longer available at the UE. In some cases, determining that a PDU session is no longer available at the UE may be based on determining that the PDU session is currently not active at the UE. In some cases, determining that a PDU session is no longer available at the UE may be based on determining that the PDU session is deactivated at the UE.

[0035] Method 100 also includes determining 106 that a registration request message indicating that the PDU session is no longer available at the UE has not been sent to the network.

[0036] Method 100 further includes, based on the determination that a registration request message has not yet been sent to the network, sending to the network 108 a message including a PDU session state IE, the PDU session state IE indicating that the PDU session is no longer available at the UE. In some cases, the message including this PDU session state IE may be a service request message. In some cases, the message including this PDU session state IE may be a registration request message.

[0037] Method 100 further includes determining, based on receiving a reply message from the network corresponding to a message including the PDU session state IE, that the network 110 has been informed that the PDU session is no longer available at the UE. The UE may wait to determine that the network has been so informed until it receives a reply message at the UE. This allows the UE to subsequently update the network with additional indication that the PDU session is unavailable if the network has never received a reply message (and therefore the reply message has never been sent to the UE) (as described below with respect to method 200). In some embodiments, the reply message may be a service acceptance message or a service rejection message. In some embodiments, the reply message may be a registration acceptance message.

[0038] Figure 2 A method 200 for a UE according to an implementation scheme is shown. The method 200 includes receiving one of a 202 notification request message and an MT paging from the network.

[0039] The method 200 also includes determining 204 that a PDU session previously available at the UE is no longer available at the UE. In some cases, determining that a PDU session is no longer available at the UE may be based on determining that the PDU session is currently not active at the UE. In some cases, determining that a PDU session is no longer available at the UE may be based on determining that the PDU session has been deactivated at the UE.

[0040] Method 200 also includes determining 206 that a registration request message indicating that the PDU session is no longer available at the UE has not been sent to the network.

[0041] Method 200 further includes, based on the determination that a registration request message has not yet been sent to the network, sending to the network 208 a message including a PDU session state IE, the PDU session state IE indicating that the PDU session is no longer available at the UE. In some cases, the message including this PDU session state IE may be a service request message. In some cases, the message including this PDU session state IE may be a registration request message.

[0042] Method 200 also includes determining, based on the failure to receive a reply message from the network corresponding to a message including the PDU session state IE, that 210 the network has not been informed that the PDU session is no longer available at the UE.

[0043] Method 200 further includes sending a second message 212 to the network, based on determining that the network has not been informed that the PDU session is no longer available at the UE, including a second PDU session state IE, which indicates that the PDU session is no longer available at the UE.

[0044] Figure 3 A method 300 for a UE according to an implementation scheme is shown. The method 300 includes receiving one of a notification request message 302 from the network and an MT paging.

[0045] Method 300 also includes determining 304 that a PDU session previously available at the UE is no longer available at the UE.

[0046] Method 300 also includes determining 306 that a registration request message indicating that the PDU session is no longer available at the UE has not been sent to the network.

[0047] Method 300 further includes sending a PDU session release request message to the network for the PDU session based on the determination that the registration request message has not yet been sent to the network.

[0048] When pending uplink (UL) user data or UL control signaling exists in UE mode, a change in the UE's PDU session state detected at the UE may occur in a situation where the UE can be configured to trigger a service request procedure by sending a service request message with a PDU session state IE, or to trigger a registration procedure by sending a registration request message with a PDU session state IE. In some cases involving a service request procedure, this may occur when the UE is in 5GMM-REGISTERED.NORMAL-SERVICE mode. In other cases involving a registration request procedure, this may occur when the UE is in 5GMM-REGISTERED.UPDATE-NEEDED mode or 5GMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE mode.

[0049] In other cases, during the period when a change in PDU session state is detected at the UE, if there is no pending UL data or UL signaling at the UE (and / or if the UE is not in 5GMM-REGISTERED.NORMAL-SERVICE mode, 5GMM-REGISTERED.UPDATE-NEEDED mode, or 5GMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE mode), the UE may not be configured to respond to the detected change in PDU session state by sending a service request message with the PDU session state IE or by sending a registration request message with the PDU session state IE.

[0050] It is more efficient to check these conditions and send either a service request message or a registration request message containing the PDU session state IE when the UE detects a change in the PDU session state than to passively wait for a subsequent message that happens to have the PDU session state IE to ensure synchronization between the UE and the network (after the change in the PDU session state). For example, checking these conditions and sending the message when detected allows the network to synchronize with the UE more immediately.

[0051] Furthermore, while a service request message or a registration request message can be sent when the above conditions are detected, it may be more efficient to use a service request message instead of a registration request message due to the increased size of the registration request message compared to the service request message, and / or the increased size of the response registration acceptance message compared to the service acceptance message.

[0052] It is conceivable that this functionality could be applied to many situations, including those relating to all the conditions mentioned in TS 24.501 Part 5.6.1.1, if these conditions apply when a local PDU release occurs at the UE. For example, some such conditions might involve a UE having pending UL data and having locally deactivated its PDU session. Upon regaining service, the UE could then immediately initiate a service request procedure (instead of using a registration request) by sending a service request message with a PDU session state IE indicating that the PDU session was locally released. In another example, some such conditions might involve a UE having pending emergency calls and having locally deactivated its PDU session. In these cases, the UE could send a service request message with the service type "emergency" and a PDU session state IE indicating that the PDU session is inactive. In yet another example of this, an emergency service rollback request pending method might be included.

[0053] Figure 4A method 400 for a UE according to an implementation scheme is shown. Method 400 includes determining 402 that the UE has data to be transmitted to the network on the UL. This data may be user data or control signaling between the UE and the network.

[0054] Method 400 also includes detecting 404 changes in the PDU session state maintained by the UE.

[0055] Method 400 further includes sending a message 406 including a PDU session state IE to the network based on determining that the UE has pending data for the UL and detecting a change in the PDU session state maintained by the UE. The PDU session state IE indicates the PDU session state maintained by the UE. In some embodiments, the message including the PDU session state IE may be a service request message. In some embodiments, the message including the PDU session state IE may be a registration request message.

[0056] Method 400 further includes determining, based on receiving a reply message from the network corresponding to a message including the PDU session state IE, that 408 the network has received the PDU session state maintained by the UE. The UE may wait to determine that the network has been so informed until it receives the reply message at the UE. This allows the UE to subsequently update the network with additional indications (as described below with respect to method 500) that the PDU session is unavailable if the network has never received the reply message (and therefore the reply message has never been sent to the UE). In some embodiments, the reply message may be a service acceptance message or a service rejection message. In some embodiments, the reply message may be a registration acceptance message.

[0057] Figure 5 A method 500 for a UE according to an implementation scheme is shown. Method 500 includes determining 502 that the UE has data to be transmitted to the network on the UL. This data may be user data or control signaling between the UE and the network.

[0058] Method 500 also includes detecting 504 changes in the PDU session state maintained by the UE.

[0059] Method 500 further includes, based on determining that the UE has pending data for the UL and detecting a change in the PDU session state maintained by the UE, sending 506 a message to the network including a PDU session state IE indicating the PDU session state. In some embodiments, the message including the PDU session state IE may be a service request message. In some embodiments, the message including the PDU session state IE may be a registration request message.

[0060] Method 500 further includes determining, based on the failure to receive a reply message from the network corresponding to a message including the PDU session state IE, that the network has not yet received the PDU session state maintained by the UE.

[0061] Method 500 further includes sending a second message 510 to the network, based on determining that the network has not yet received a PDU session state maintained by the UE, including a second PDU session state IE, the second PDU session state IE indicating a PDU session state maintained by the UE.

[0062] Service requests sent by the UE to the network can be processed at, for example, the AMF (Application Function) of the network. During this processing, the AMF may determine that a PDU session active at the UE (as indicated in the PDU session state IE in the service request) is active at the network. Therefore, the AMF can be configured to send a service accept message (or service reject message) to the UE in response to the service request message that does not contain the PDU session state IE. The UE can be configured to determine, based on the absence of the PDU session state IE in the service accept message (or service reject message), that a PDU session active at the UE is active at the network and / or a PDU session inactive at the UE is inactive at the network. In this way, synchronization can be ensured at both the UE and the AMF without the AMF sending the PDU session state IE (saving the aforementioned associated resource costs).

[0063] Figure 6 A method 600 for an AMF (Active Network Function) of a network according to an implementation scheme is illustrated. Method 600 includes processing 602 a service request message sent by a UE to the network, the service request message indicating that one or more PDU sessions are active at the UE.

[0064] Method 600 also includes determining, based on the PDU session state maintained at the AMF, that 604 one or more PDU sessions that are active at the UE are active at the network.

[0065] Method 600 further includes generating a service accept message 606 that does not include the PDU session state IE in response to determining that one or more PDU sessions that are active at the UE are active at the network.

[0066] Figure 7 A method 700 for a UE according to an embodiment is illustrated. Method 700 includes sending a service request message 702 to the network containing a first PDU session state IE, the service request message indicating that one or more PDU sessions are active at the UE.

[0067] Method 700 also includes receiving a service acceptance message 704 from the network in response to a service request message.

[0068] Method 700 also includes determining that 706, the service acceptance message from the network, does not contain any PDU session state IE.

[0069] Method 700 also includes determining, based on the determination that the service acceptance message from the network does not contain any PDU session state IE, that 708 one or more PDU sessions that are active at the UE are active at the network.

[0070] In some cases, entities in a wireless communication system (e.g., a network UE or AMF) may need to ensure that the PDU session state is not perceived as having been indicated to a peer entity (e.g., a network UE or AMF) until certain messaging occurs successfully. If this cannot be confirmed, the peer entity can be subsequently updated (later) using a message containing the entity's PDU session state to achieve synchronization.

[0071] For example, the UE may be unsure whether it has indicated its PDU session state to the AMF by sending a service request message containing the PDU session state IE until it receives a service accept message or service reject message in response to the service request message at the UE. Similarly, the UE may be unsure whether it has indicated its PDU session state to the AMF by sending a registration request message until it receives a registration accept message in response to the registration request message at the UE. Failure to receive such a responsive message (e.g., in either of the above cases) allows the UE to determine that its PDU session state has not yet been indicated to the AMF. This determination may ultimately lead the UE to subsequently update the network using a (later) message that includes the PDU session state IE indicating the PDU session state at the UE later. As described above, examples of this behavior from the UE's perspective have been given with respect to methods 200 and 500.

[0072] For example, the AMF may determine that it has not yet indicated to the UE the PDU session state maintained by the AMF if, before a service accept or service reject message indicating such indication has been sent to the UE in response to a service request message from a UE-initiated service request procedure, the AMF detects a lower-level fault (e.g., a fault reported by the Access Stratum (AS) to the Non-Access Stratum (NAS) that cannot be corrected at the AS level, meaning the NAS signaling connection is unavailable). Similarly, if the AMF detects a lower-level fault before a registration accept message has been sent to the UE in response to a registration request message from a UE-initiated registration procedure, the AMF may determine that its PDU session state has not yet been indicated to the UE. This determination may ultimately lead the AMF to subsequently update the UE with a PDU session state IE indicating the PDU session state at the AMF later (e.g., after the lower-level fault has been resolved). It should be noted that in these cases, the sending of a service accept message, service reject message, or registration accept message may indicate the PDU session state maintained by the AMF, even if the PDU session state IE is not included (e.g., by simply responding to a message received from the UE in the manner described above).

[0073] Figure 8 A method 800 for an AMF (Advanced Feature Function) in a network according to an embodiment is shown. Method 800 includes detecting 802 lower-level faults at the AMF.

[0074] Method 800 also includes determining that the network did not send a reply message corresponding to a message including the PDU session state IE received from the UE at the network prior to a lower-level failure.

[0075] Method 800 also includes determining, based on the fact that the network did not send a reply message before the lower-level failure, that the PDU session state maintained by the AMF has not yet been indicated to the UE.

[0076] Method 800 further includes sending a second message to the UE, 808, to the UE, based on the determination that the PDU session state maintained by the AMF has not yet been indicated to the UE, the PDU session state IE indicating the PDU session state maintained by the AMF.

[0077] For some wireless communication systems, it can be determined that the UE is expected to respond to each MT paging from the network using service requests that include the PDU session state IE, so that the network is aware of this information in all such cases. This may help resolve situations where, for example, the PDU session is active at the network but not at the UE, and the network triggers an MT paging attempt to establish a bearer within such PDU session.

[0078] Figure 9A method 900 for a UE according to an implementation scheme is shown. Method 900 includes receiving a paging 902MT from a network.

[0079] Method 900 further includes, in response to MT paging, sending 904 a service request message including a PDU session state IE, the PDU session state IE indicating that one or more PDU sessions are active at the UE.

[0080] For some wireless communication systems, a UE may be in 5GMM-CONNECTED mode while having a Radio Resource Control (RRC) inactivity indication / mode (meaning the Data Radio Bearer (DRB) corresponding to a PDU session is inactive). This could correspond to an example where the UE has a first DRB that is allocated and active at the UE, corresponding to a first (active) PDU session. Later, since there is no data packet exchange between the UE and the network for this first PDU session, the gNB decides to suspend the DRB. In this case, the UE enters an RRC inactivity state (e.g., it has an active PDU, but the corresponding DRB is suspended).

[0081] In these cases, if the network is unaware that the second PDU session is inactive at the UE, it may attempt to establish a DRB for the second PDU session (which may also correspond to an active PDU session on the network side) for data transmission to the UE. In this scenario, the UE can respond to this attempt with a message containing a PDU session state IE indicating the active and inactive PDU sessions at the UE, thereby synchronizing the PDU session state between the UE and the network and informing the network that the second PDU session is inactive at the UE. In some cases, this could be a service request message. In other cases, the UE may optionally send a registration request message with a PDU session state IE instead of a service request message containing the PDU session state IE. In other words, in response to determining that the DRB of the second PDU session corresponds to a PDU session that is not active at the UE, the UE does not send a service request message containing the PDU session state IE.

[0082] Figure 10 A method 1000 for a UE according to an implementation scheme is shown. Method 1000 includes receiving 1002 an instruction from a network to establish a DRB with the network.

[0083] Method 1000 also includes determining that 1004DRB corresponds to a PDU session that is not active at the UE.

[0084] Method 1000 further includes, in response to determining that the DRB corresponds to a PDU session that is not active at the UE, sending 1006 a message to the network including a PDU session state IE, the PDU session state IE indicating that the PDU session is not active at the UE. In some cases, this message may be a service request message. In other cases, this message may be a registration request message. When using a registration request message, in response to determining that the DRB of the PDU session corresponds to a PDU session that is not active at the UE, the UE may not send a service request message including the PDU session state IE.

[0085] Method 1000 can be executed when the UE is in 5GMM-CONNECTED mode and / or when the UE has an RRC inactivity indication.

[0086] Various scenarios in which one or more of the methods described above can be used will now be presented. These scenarios are given by way of example rather than limitation. These scenarios can be applied to wireless communication systems, such as 5G NR systems.

[0087] Scene #1

[0088] In the first scenario, the UE may need to release its PDU session in order to request an emergency PDU session. In this case, the UE can perform a local release of the PDU session or release the PDU session via explicit signaling with the network. If the UE performs a local release, the UE can then initiate a service request procedure or a registration procedure.

[0089] In the case of a service request procedure, if the UE is in 5GMM-REGISTERED.NORMAL-SERVICE mode for the current access and the conditions for triggering the service request message apply, the UE may include the PDU session state IE in the service request message of the service request procedure. In other cases involving a service request procedure, if the UE receives an MT paging or notification request for the current access type during the processing of a PDU session release procedure, the UE may include the PDU session state IE in the service request message in response to the MT paging or notification request. In some of these cases involving a service request procedure, the PDU session state IE in the service request message may indicate that the PDU session is inactive.

[0090] In other cases involving service request procedures, the PDU session state IE of the service request message may not indicate that the PDU session is inactive, but a subsequent PDU session release request message may be sent after the service request procedure is completed to release the PDU session at the network (and then stop the T3582 timer). This may be applicable to situations where local release at the UE is pending but has not yet been completed.

[0091] In the case of a registration procedure, such a procedure can provide the network with mobility and periodic registration updates, and can indicate the PDU session state (IE) to the network in the registration request message.

[0092] Scene #2

[0093] In the second scenario, the anomaly can be identified at the UE. One such anomaly in some wireless communication systems might be the expiration of the T3582 timer. The expiration of the T3582 timer indicates that the UE has failed to receive a response from the network to a PDU session release request message triggered by the UE.

[0094] When the T3582 timer expires for the first time, the UE can retransmit the PDU session release request message and restart the T3582 timer. This retransmission can be repeated four times. When the T3582 timer expires for the fifth time, the UE can abort the procedure, release the assigned Program Transaction Identifier (PTI), and perform a local release of the PDU session. The UE can then initiate a service request procedure or a registration procedure.

[0095] In the case of a service request procedure, if the UE is in 5GMM-REGISTERED.NORMAL-SERVICE mode for the current access and the conditions for triggering a service request message apply, the UE may include the PDU session state IE in the service request message of the service request procedure. In other cases involving a service request procedure, if the UE receives an MT paging or notification request for the current access type during the processing of a PDU session release procedure, the UE may include the PDU session state IE in the service request message in response to the MT paging or notification request.

[0096] In the case of a registration procedure, such a procedure can provide the network with mobility and periodic registration updates, and can indicate the PDU session state (IE) to the network in the registration request message.

[0097] Scene #3

[0098] In the third scenario, the UE may send a service request message to the network according to a service request procedure. Such a service request message may contain a PDU session state IE, which may indicate a single-access PDU session that is not in 5GSM state PDU SESSION INACTIVE in the UE associated with the access type sent by the service request message, and a multi-access (MA) PDU session that is not in 5GSM state PDU SESSION INACTIVE in the access type sent by the service request message and has user plane resources established in the UE.

[0099] In some of these scenarios, when the UE needs to indicate the PDU session status to the network after performing a local release of the PDU session, the PDU session status IE can be included in the service request message of the service request procedure.

[0100] Scene #4

[0101] In the fourth scenario, anomalies can be identified at the network level. One such anomaly might be a lower-level failure. In these cases, if the lower-level failure occurs before a service rejection message has been sent to the UE (e.g., in some cases, in response to a service request message sent by the UE), or if the lower-level failure occurs before the network's AMF completes the service request procedure, or if the lower-level failure occurs before a network-initiated PDU session release procedure successfully completes, the AMF enters and / or remains in 5GMM-IDLE mode, and the status of PDU session state synchronization between the network and the UE remains pending. This determination may ultimately lead the network to subsequently update the UE with a message including the PDU session state IE, indicating the PDU session state later at the AMF.

[0102] Scene #5

[0103] In the fifth scenario, regarding the service request procedure to be accepted by the network, the network's AMF may need to initiate PDU session state synchronization, or the PDU session state IE may have already been included in the service request message from the UE. In the case of the service request message from the UE, it is possible that the AMF detects a difference between the PDU session state at the AMF and the PDU session state reported in the PDU session state IE from the service request message, or that the PDU session release procedure initiated by the network has not completed successfully. In this case, the AMF may include the PDU session state IE in the service acceptance message to be sent to the UE to indicate which single access PDU session associated with the access type sent by the service acceptance message in the AMF is not in 5GM state PDUSESSION INACTIVE, and further indicate which MA PDU sessions are not in 5GSM state PDUSESSION INACTIVE and have user plane resources established in the AMF for the access type sent by the service request message.

[0104] Scene #6

[0105] In the sixth scenario, regarding service request procedures not accepted by the network, the network's AMF may need to initiate PDU session state synchronization, or the PDU session state IE may have already been included in the service request message from the UE. In the case of a service request message from the UE, it's possible that the AMF detects a difference between the PDU session state at the AMF and the PDU session state reported in the PDU session state IE from the service request message. In this case, the AMF may include the PDU session state IE in the service rejection message to indicate which PDU sessions associated with the access type sent by the service rejection message are active in the AMF. Alternatively, if the PDU session state IE sent by the UE in a registration request message or service request message indicates that the same group of PDU sessions are active on the network side, the AMF may decide not to provide the PDU session state IE in the service rejection message.

[0106] Scene #7

[0107] In the seventh scenario, if the UE is in the 5GMM-REGISTERED.NO-CELL-AVAILABLE state, 5GMM-REGISTERED.PLMN-SEARCH mode, 5GMM-REGISTERED.LIMITED-SERVICE mode, or 5GMM-REGISTERED.UPDATE-NEEDED mode on 3GPP access, the UE can respond with a notification response message indicating that the user plane resources of the PDU session could not be rebuilt.

[0108] Furthermore, if the UE has already locally released any PDU sessions, this notification response message may include the PDU session status IE, where the PDU session status IE indicates a single-access PDU session that is not in 5GMM state PDU SESSIONINACTIVE in the UE associated with the 3GPP access type, and an MA PDU session that is not in 5GSM state PDU SESSIONINACTIVE in the UE and has user plane resources established with the 3GPP access type. If the UE has not yet locally released any PDU sessions, this PDU session status IE may not be included, in which case the network has been notified of such locally released PDU sessions.

[0109] Figure 11 This is a block diagram of a configurable exemplary UE 1100 according to various embodiments of the present disclosure, including instructions executed on a computer-readable medium corresponding to any of the exemplary methods and / or programs described herein. UE 1100 includes one or more processors 1102, transceiver 1104, memory 1106, user interface 1108, and control interface 1110.

[0110] One or more processors 1102 may include, for example, an application processor, an audio digital signal processor, a central processing unit, and / or one or more baseband processors. Each of the one or more processors 1102 may include internal memory and / or may include an interface for communicating with external memory (including memory 1106). The internal or external memory may store software code, programs, and / or instructions that are executed by one or more processors 1102 to configure and / or facilitate the UE 1100 to perform various operations, including those described herein. For example, the execution of instructions may configure the UE 1100 to communicate using one or more wired or wireless communication protocols, including one or more wireless communication protocols standardized by 3GPP, such as those commonly referred to as 5G / NR, LTE, LTE-A, UMTS, HSPA, GSM, GPRS, EDGE, etc., or any other current or future protocols that may be used in conjunction with one or more transceivers 1104, user interface 1108, and / or control interface 1110. For example, one or more processors 1102 may execute program code stored in memory 1106 or other memory, which corresponds to the MAC, RLC, PDCP, and RRC layer protocols standardized by 3GPP (e.g., for NR and / or LTE). Alternatively, processor 1102 may execute program code stored in memory 1106 or other memory, which, together with one or more transceivers 1104, implements corresponding PHY layer protocols, such as Orthogonal Frequency Division Multiplexing (OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), and Single Carrier Frequency Division Multiple Access (SC-FDMA).

[0111] Memory 1106 may include memory regions for one or more processors 1102 to store variables used in the protocols, configurations, controls, and other functions of UE 1100 (including operations corresponding to or including any of the exemplary methods and / or programs described herein). Furthermore, memory 1106 may include non-volatile memory (e.g., flash memory), volatile memory (e.g., static or dynamic RAM), or combinations thereof. Additionally, memory 1106 may interact with a memory slot through which one or more removable memory cards of various formats (e.g., SD cards, Memory Sticks, Compact Flash, etc.) can be inserted and removed.

[0112] One or more transceivers 1104 may include radio frequency transmitter and / or receiver circuitry that facilitates communication between the UE 1100 and other equipment supporting similar wireless communication standards and / or protocols. For example, one or more transceivers 1104 may include switches, mixer circuitry, amplifier circuitry, filter circuitry, and synthesizer circuitry. Such RF circuitry may include a receive signal path having circuitry for down-converting RF signals received from a front-end module (FEM) and providing baseband signals to one or more processors 1102. The RF circuitry may also include a transmit signal path that may include circuitry for up-converting the baseband signals provided by the baseband processor and providing an RF output signal for transmission to the FEM. The FEM may include a receive signal path that may include circuitry configured to operate on RF signals received from one or more antennas, amplify the received signals, and provide an amplified version of the received signals to the RF circuitry for further processing. The FEM may also include a transmit signal path that may include circuitry configured to amplify transmit signals provided by the RF circuitry for transmission by one or more antennas. In various implementations, amplification along the transmit or receive signal path can be performed only in the RF circuitry, only in the FEM, or in both the RF and FEM circuitries. In some implementations, the FEM circuitry may include a TX / RX switch to switch between transmit and receive mode operation.

[0113] In some exemplary embodiments, one or more transceivers 1104 include transmitters and receivers that enable the UE 1100 to communicate with various 5G / NR networks according to various protocols and / or methods proposed for standardization by 3GPP and / or other standards bodies. For example, such functionality may operate cooperatively with one or more processors 1102 to implement a PHY layer based on OFDM, OFDMA, and / or SC-FDMA technologies, as described herein with reference to other figures.

[0114] User interface 1108 may take various forms depending on the specific implementation, or may not be present in UE 1100. In some implementations, user interface 1108 includes a microphone, speaker, slide button, pressable button, display, touchscreen display, mechanical or virtual keypad, mechanical or virtual keyboard, and / or any other user interface features typically present on a mobile phone. In other implementations, UE 1100 may include a tablet computing device with a large touchscreen display. In such implementations, one or more mechanical features of user interface 1108 may be replaced by equivalent or functionally equivalent virtual user interface features (e.g., virtual keypad, virtual buttons, etc.) implemented using a touchscreen display, as is well known to those skilled in the art. In other implementations, UE 1100 may be a digital computing device, such as a laptop computer, desktop computer, workstation, etc., which includes a mechanical keyboard that may be integrated, detachable, or removable according to a particular exemplary implementation. Such digital computing devices may also include a touchscreen display. Many exemplary embodiments of the UE 1100 with a touchscreen display are capable of receiving user input, such as input related to exemplary methods and / or procedures described herein or known to those skilled in the art.

[0115] In some exemplary embodiments of this disclosure, UE 1100 includes an orientation sensor that can be used in various ways by features and functions of UE 1100. For example, UE 1100 can use the output of the orientation sensor to determine when a user has changed the physical orientation of the touchscreen display of UE 1100. An indication signal from the orientation sensor can be used by any application executing on UE 1100 to automatically change the orientation of the screen display (e.g., from portrait to landscape) when the indication signal indicates a change of approximately 90 degrees in the physical orientation of the device. Thus, the application is able to maintain the screen display in a user-readable manner regardless of the physical orientation of the device. Additionally, the output of the orientation sensor can be used in conjunction with various exemplary embodiments of this disclosure.

[0116] The control interface 1110 may take various forms depending on the specific implementation. For example, the control interface 1110 may include an RS-232 interface, an RS-485 interface, a USB interface, an HDMI interface, a Bluetooth interface, an IEEE (“FireWire”) interface, and an I / O interface. 2 Interfaces include C-type interfaces, PCMCIA interfaces, etc. In some exemplary embodiments of this disclosure, control interface 1360 may include an IEEE 802.3 Ethernet interface, as described above. In some embodiments of this disclosure, control interface 1110 may include analog interface circuitry, including, for example, one or more digital-to-analog (D / A) converters and / or analog-to-digital (A / D) converters.

[0117] Those skilled in the art will recognize that the list of features, interfaces, and radio frequency communication standards above is merely exemplary and not limited to the scope of this disclosure. In other words, UE 1100 may include more than Figure 11 Further functionalities are shown, including, for example, a video and / or still image camera, a microphone, a media player, and / or a recorder. Additionally, one or more transceivers 1104 may include circuitry for communicating using additional radio frequency communication standards, including Bluetooth, GPS, and / or others. Furthermore, one or more processors 1102 may execute software code stored in memory 1106 to control such additional functionalities. For example, directional velocity and / or position estimates output from a GPS receiver can be used by any application executing on the UE 1100, including various exemplary methods and / or computer-readable media according to various exemplary embodiments of this disclosure.

[0118] Figure 12 This is a block diagram of a configurable exemplary network node 1200 according to various embodiments of the present disclosure, including instructions executed on a computer-readable medium corresponding to any of the exemplary methods and / or programs described herein.

[0119] Network node 1200 includes one or more processors 1202, a radio network interface 1204, a memory 1206, a core network interface 1208, and other interfaces 1210. Network node 1200 may include components such as base stations, eNBs, gNBs, access nodes, or network nodes.

[0120] One or more processors 1202 may include any type of processor or processing circuitry and may be configured to perform one of the methods or programs disclosed herein. Memory 1206 may store software code, programs, and / or instructions executed by one or more processors 1202 to configure network node 1200 to perform various operations, including those described herein. For example, execution of such stored instructions may configure network node 1200 to communicate with one or more other devices using protocols according to various embodiments of this disclosure, including one or more methods and / or programs discussed above. Furthermore, execution of such stored instructions may configure and / or facilitate network node 1200 to communicate with one or more other devices using other protocols or protocol layers, such as one or more of the PHY, MAC, RLC, PDCP, and RRC layer protocols standardized by 3GPP for LTE, LTE-A, and / or NR, or any other higher-level protocol used in conjunction with radio network interface 1204 and core network interface 1208. By way of example, and not limitation, the core network interface 1208 includes an S1 interface, and the radio network interface 1204 may include a Uu interface, such as those standardized by 3GPP. Memory 1206 may also store variables used in the protocols, configurations, control, and other functions of the network node 1200. Therefore, memory 1206 may include non-volatile memory (e.g., flash memory, hard disk, etc.), volatile memory (e.g., static or dynamic RAM), network-based (e.g., “cloud”) storage devices, or combinations thereof.

[0121] The radio network interface 1204 may include a transmitter, receiver, signal processor, ASIC, antenna, beamforming unit, and other circuitry enabling the network node 1200 to communicate with other equipment (in some embodiments, such as multiple compatible user equipment (UEs)). In some embodiments, the network node 1200 may include various protocols or protocol layers, such as the PHY, MAC, RLC, PDCP, and RRC layer protocols standardized by 3GPP for LTE, LTE-A, and / or 5G / NR. According to further embodiments of this disclosure, the radio network interface 1204 may include a PHY layer based on OFDM, OFDMA, and / or SC-FDMA technologies. In some embodiments, the functionality of such a PHY layer may be provided collaboratively by the radio network interface 1204 and one or more processors 1202.

[0122] The core network interface 1208 may include a transmitter, a receiver, and other circuitry enabling the network node 1200 to communicate with other equipment in the core network (in some embodiments, such as a circuit-switched (CS) and / or packet-switched (PS) core network). In some embodiments, the core network interface 1208 may include an S1 interface standardized by 3GPP. In some embodiments, the core network interface 1208 may include one or more interfaces to one or more SGW, MME, SGSN, GGSN, and other physical devices, which include functionality known to those skilled in the art in GERAN, UTRAN, E-UTRAN, and CDMA2000 core networks. In some embodiments, these one or more interfaces may be multiplexed together on a single physical interface. In some embodiments, the lower layers of the core network interface 1208 may include one or more of Asynchronous Transfer Mode (ATM), Internet Protocol over Ethernet (IP), SDH over fiber, T1 / E1 / PDH over copper, microwave radio, or other wired or wireless transmission technologies known to those skilled in the art.

[0123] Other interfaces 1210 may include transmitters, receivers, and other circuitry that enables network node 1200 to communicate with external networks, computers, databases, etc., for the operation, management, and maintenance of network node 1200 or other network equipment operatively connected thereto.

[0124] Exemplary System Architecture

[0125] In some implementations, the 5G system architecture supports data connectivity and services, enabling deployment using technologies such as network function virtualization and software-defined networking. The 5G system architecture can leverage service-based interactions between control plane network functions. Separating user plane functions from control plane functions allows for independent scalability, evolution, and flexible deployment (e.g., centralized or distributed (remote) locations). Modular function design allows for function reuse and enables flexible and efficient network slicing. Network functions and their network function services can interact directly or indirectly with another NF and its network function services via a service communication broker. Another intermediate function helps route control plane messages. This architecture minimizes dependencies between the AN and CN. The architecture may include an aggregated core network with a common AN-CN interface integrating different access types (e.g., 3GPP access and non-3GPP access). The architecture also supports a unified authentication framework, stateless NFs that decouple compute and storage resources, capability exposure, concurrent access to local and centralized services (to support low-latency services and access to local data networks, with user plane functions deployed near the AN), and / or roaming in the visited PLMN using both home-routed traffic and local breakout traffic.

[0126] A 5G architecture can be defined as service-based, and interactions between network functions can include service-based representations, where a network function within the control plane (e.g., an AMF) enables other authorized network functions to access its services. Service-based representations can also include point-to-point reference points. Reference point representations can also be used to illustrate interactions between NF services within network functions described by point-to-point reference points (e.g., N11) between any two network functions (e.g., AMF and SMF).

[0127] Figure 13 A service-based architecture 1300 in 5GS according to one implementation is shown. As described in 3GPP TS23.501, the service-based architecture 1300 includes NFs such as NSSF 1308, NEF 1310, NRF 1314, PCF 1312, UDM 1326, AUSF 1318, AMF 1320, and SMF 1322 for communicating with UE 1316, (R)AN 1306, UPF 1302, and DN 1304. NFs and NF services can communicate directly (referred to as direct communication) or indirectly via SCP 1324 (referred to as indirect communication). Figure 13 The corresponding service-based interfaces are also shown, including Nutm, Naf, Nudm, Npcf, Nsmf, Nnrf, Namf, Nnef, Nnssf, and Nausf, as well as reference points N1, N2, N3, N4, and N6. The following describes the... Figure 13The NF shown provides some exemplary functionalities.

[0128] NSSF 1308 supports functions such as: selecting the set of network slice instances serving the UE; determining the allowed NSSAIs and, if necessary, the mapping to subscribed S-NSSAIs; determining the configured NSSAIs and, if necessary, the mapping to subscribed S-NSSAIs; and / or determining the set of AMFs to be used to serve the UE, or, based on the configuration, possibly by querying the NRF to determine a list of candidate AMFs.

[0129] The NEF 1310 supports the exposure of capabilities and events. NF capabilities and events can be securely exposed by the NEF 1310 (e.g., for third parties, application functions, and / or edge computing). The NEF 1310 can use a standardized interface (Nudr) to the UDR to store / retrieve information as structured data. The NEF 1310 can also securely provide information from external applications to the 3GPP network and can provide application functions to securely provide information to the 3GPP network (e.g., anticipated UE behavior, 5GLAN group information, and service-specific information), where the NEF 1310 can authenticate and authorize and help restrict application functions. The NEF 1310 provides internal-external information translation by translating information exchanged with the AF and information exchanged with internal network functions. For example, the NEF 1310 translates between the AF service identifier and internal 5G core information (such as DNN and S-NSSAI). The NEF 1310 can handle the masking of network and user-sensitive information to external AFs according to network policies. The NEF 1310 can receive information from other network functions (based on the exposure capabilities of those functions) and store the received information as structured data using a standardized interface to the UDR. The stored information can then be accessed by the NEF 1310 and re-exposed to other network and application functions for purposes such as analysis. For external exposure of services related to a specific UE, the NEF 1310 can reside in the HPLMN. Depending on the operator agreement, the NEF 1310 in the HPLMN can have an interface with the NF in the VPLMN. When the UE is able to switch between EPC and 5GC, SCEF+NEF can be used for service exposure.

[0130] NRF 1314 supports service discovery by receiving NF discovery requests from NF instances or SCPs and providing information about discovered NF instances to the NF instances or SCPs. NRF 1314 also supports P-CSCF discovery (a special case of SMF discovery of AFs), maintaining NF profiles of available NF instances and their supported services, and / or notifying subscribed NF service consumers or SCPs of newly registered / updated / deregistered NF instances along with their NF services. In the context of network slicing, multiple NRFs can be deployed at different levels depending on the network implementation, such as PLMN level (NRFs configured with information about the entire PLMN), shared slice level (NRFs configured with information about the network slice set), and / or slice-specific level (NRFs configured with information about the S-NSSAI). In the context of roaming, multiple NRFs can be deployed in different networks, where the NRF in the visited PLMN (referred to as vNRF) is configured with information about the visited PLMN, and the NRF in the home PLMN (referred to as hNRF) is configured with information about the home PLMN, referenced by the vNRF via the N27 interface.

[0131] PCF 1312 supports a unified policy framework for managing network behavior. PCF 1312 provides policy rules for control plane functions to enforce them. PCF 1312 accesses subscription information related to policy decisions in the Unified Data Repository (UDR). PCF 1312 can access the UDR located in the same PLMN as PCF.

[0132] UDM 1326 supports the generation of 3GPP AKA authentication credentials, user identity processing (e.g., storage and management of each user's SUPI in a 5G system), de-hiding of privacy-preserving subscription identifiers (SUCI), access authorization based on subscription data (e.g., roaming restrictions), UE service NF registration management (e.g., storing AMF for UE storage services, storing SMF for UE PDU sessions), service / session continuity (e.g., by maintaining SMF / DNN allocation for ongoing sessions), MT-SMS delivery, lawful interception functionality (especially in outbound roaming scenarios where the UDM is the only contact point of the LI), subscription management, SMS management, 5GLAN group management processing, and / or external parameter configuration (expected UE behavior parameters or network configuration parameters). To provide these functions, UDM 1326 uses subscription data (including authentication data) that can be stored in a UDR. In this case, the UDM implements application logic and may not require internal user data storage, and several different UDMs can provide services to the same user in different transactions. UDM 1326 may reside in the HPLMN of its subscribers and can access information of the UDR located in the same PLMN.

[0133] AUSF 1318 supports authentication for 3GPP access and untrusted non-3GPP access. AUSF 1318 also provides support for network slicing-specific authentication and authorization.

[0134] The AMF 1320 supports the termination of the RAN CP interface (N2), the termination of the NAS (N1) for NAS encryption and integrity protection, registration management, connection management, reachability management, mobility management, lawful interception (for AMF events and interfaces to the LI system), transmission of SM messages between the UE and SMF, transparent proxy for routing SM messages, access authentication, access authorization, transmission of SMS messages between the UE and SMSF, SEAF, location service management for regulated services, transmission of location service messages between the UE and LMF and between the RAN and LMF, EPS bearer ID allocation for interoperability with EPS, UE mobility event notification, control plane CIoT 5GS optimization, user plane CIoT 5GS optimization, configuration of external parameters (expected UE behavior parameters or network configuration parameters), and / or network slice-specific authentication and authorization. Some or all of the AMF functions can be supported in a single instance of the AMF 1320. Regardless of the number of network functions, in some implementations, only one NAS interface instance per access network between the UE and the CN terminates with one of the network functions that implements at least NAS security and mobility management. The AMF 1320 may also include policy-related functions.

[0135] In addition to the functions described above, the AMF 1320 may also include the following functions supporting non-3GPP access networks: support for the N2 interface with N3IWF / TNGF, on which some information (e.g., 3GPP cell identification) and procedures (e.g., handover-related) defined on 3GPP access may not be applicable, and non-3GPP access-specific information not applicable to 3GPP access can be applied; support for NAS signaling by the UE via N3IWF / TNGF, where some procedures supported by NAS signaling on 3GPP access may not be applicable to untrusted non-3GPP (e.g., paging) access; support for authentication of UEs connected via N3IWF / TNGF; management of mobility, authentication, and separate security context states for UEs connected via non-3GPP access or simultaneously via 3GPP access or non-3GPP access; support for effective coordination of RM management contexts on both 3GPP and non-3GPP access; and / or support for dedicated CM management contexts for UEs connecting via non-3GPP access. Support for all of the above functions may not be required in network slicing instances.

[0136] The SMF 1322 supports session management (e.g., session establishment, modification, and publication, including tunnel maintenance between UPF and AN nodes), UE IP address allocation and management (including optional authorization) (where UE IP addresses can be received from the UPF or from an external data network), DHCPv4 (server and client) and DHCPv6 (server and client) functions, the ability to respond to Address Resolution Protocol (ARP) requests and / or IPv6 neighbor request requests with local cached information based on Ethernet PDUs (e.g., the SMF responds to ARP and / or IPv6 neighbor request requests by providing the MAC address corresponding to the IP address sent in the request), selection and control of user plane functions (including controlling the UPF to proxy ARP or IPv6 neighbor discovery or forwarding all ARP / IPv6 neighbor request traffic to the SMF for Ethernet PDU sessions), traffic-directing configuration at the UPF to route traffic to the appropriate destination, and 5G VN group management (e.g., maintaining the topology of the involved PSA UPF, in the PSA...). Establish and publish N19 tunnels between UPFs, configure traffic forwarding at the UPF to apply local handover, and / or N6-based or N19-based forwarding, terminate the interface for policy control functions, lawful interception (for SM events and interfaces to the LI system), charge for data collection and support the billing interface, control and coordinate billing data collection at the UPF, terminate the SM portion of NAS messages, downlink data notification, initiator of AN-specific SM information sent to the AN via the AMF through N2, determination of the SSC mode of the session, control plane CIoT 5GS optimization, header compression, act as an I-SMF in the deployment of insertable / removable / repositionable I-SMFs, configure external parameters (expected UE behavior parameters or network configuration parameters), P-CSCF discovery for IMS services, roaming functions (e.g., handling local implementation to apply QoS). SLA (VPLMN), charging data collection and charging interface (VPLMN) and / or lawful interception (in the VPLMN for SM events and interfaces to LI systems), interaction with external DNs to transmit signaling for PDU session authentication / authorization for external DNs and / or instructing UPF and NG-RAN to perform redundant transmissions on N3 / N9 interfaces. Some or all of the SMF functions may be supported in a single instance of the SMF. However, in some implementations, not all functions need to be supported in instances of network slices. In addition to these functions, SMF 1322 may include policy-related functions.

[0137] SCP 1324 includes one or more of the following functions: indirect communication; delegated discovery; message forwarding and routing to the destination NF / NF service; communication security (e.g., authorization for NF service consumers to access NF service manufacturer APIs), load balancing, monitoring, overload control, etc.; and / or optionally interacting with a UDR to resolve UDM group ID / UDR group ID / AUSF group ID / PCF group ID / CHF group ID / HSS group ID based on UE identity (e.g., SUPI or IMPI / IMPU). Some or all of the SCP functions may be supported in a single instance of the SCP. In some implementations, SCP 1324 may be deployed in a distributed manner and / or more than one SCP may exist in the communication path between NF services. SCPs may be deployed at the PLMN level, shared slice level, and slice-specific level. Carrier deployments may be left to ensure that the SCP can communicate with the relevant NRF.

[0138] UE 1316 may include devices with radio communication capabilities. For example, UE 1316 may include a smartphone (e.g., a handheld touchscreen mobile computing device that can connect to one or more cellular networks). UE 1316 may also include any mobile or non-mobile computing device, such as a personal data assistant (PDA), pager, laptop computer, desktop computer, wireless handheld device, or any computing device that includes a wireless communication interface. UE is also referred to as a client, mobile phone, mobile device, mobile terminal, user terminal, mobile unit, mobile station, mobile user, subscriber, user, remote station, access agent, user agent, receiver, radio equipment, reconfigurable radio equipment, or reconfigurable mobile device. UE 1316 may include an IoT UE, which may include a network access layer designed to utilize low-power IoT applications with short-lived UE connections. The IoT UE may exchange data with an MTC server or device via a PLMN, other UEs using ProSe or D2D communication, sensor networks, or IoT networks using technologies such as M2M, MTC, or mMTC. M2M or MTC data exchange may be machine-initiated data exchange. An IoT network describes interconnected IoT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure). IoT UEs may execute background applications (e.g., keeping track of activity messages, status updates, etc.) to facilitate connectivity within the IoT network.

[0139] UE 1316 can be configured to connect or communicatively couple with (R)AN 1306 via radio interface 1330. This radio interface can be a physical communication interface or layer configured to operate using cellular communication protocols such as GSM, CDMA network protocols, keyless to reach (PTT), cellular PTT (POC), UMTS, 3GPP LTE, 5G, NR, etc. For example, UE 1316 and (R)AN 1306 can use a Uu interface (e.g., an LTE-Uu interface) to exchange control plane data via a protocol stack including PHY, MAC, RLC, PDCP, and RRC layers. DL transmissions can be made from (R)AN 1306 to UE 1316, and UL transmissions can be made from UE 1316 to (R)AN 1306. UE 1316 can also use a sidelink to communicate directly with another UE (not shown) for D2D, P2P, and / or ProSe communication. For example, the ProSe interface may include one or more logical channels, including but not limited to the Physical Side Link Control Channel (PSCCH), Physical Side Link Shared Channel (PSSCH), Physical Side Link Discovery Channel (PSDCH), and Physical Side Link Broadcast Channel (PSBCH).

[0140] (R)AN 1306 may include one or more access nodes, which may be referred to as a base station (BS), node B, evolved Node B (eNB), next-generation Node B (gNB), RAN node, controller, transmit-receive point (TRP), etc., and may include ground stations (e.g., terrestrial access points) or satellite stations that provide coverage within a geographic area (e.g., a cell). (R)AN 1306 may include one or more RAN nodes for providing coverage of macro cells, pico cells, femto cells, or other types of cells. Macro cells may cover a relatively large geographic area (e.g., with a radius of several kilometers) and may allow UEs to have unrestricted access with a service subscription. Pico cells may cover a relatively small geographic area and may allow UEs to have unrestricted access with a service subscription. Femto cells may cover a relatively small geographic area (e.g., a home) and may allow restricted access for UEs associated with a femto cell (e.g., a UE in a closed subscriber group (CSG), a UE of a user in a home, etc.).

[0141] Although not shown, multiple RAN nodes (such as (R)AN 1306) may be used, with Xn interfaces defined between two or more nodes. In some specific implementations, the Xn interface may include an Xn user plane (Xn-U) interface and an Xn control plane (Xn-C) interface. Xn-U provides non-guaranteed delivery of user plane PDUs and supports / provides data forwarding and flow control functions. Xn-C provides management and error handling functions for managing the functionality of the Xn-C interface; mobility support for UE 1316 in connected modes (e.g., CM-CONNECTED), including functions for managing UE mobility in connected modes between one or more (R)AN nodes. This mobility support may include context transfer from the old (source) serving (R)AN node to the new (target) serving (R)AN node; and control of user plane tunnels between the old (source) serving (R)AN node and the new (target) serving (R)AN node.

[0142] The UPF 1302 can serve as an anchor point for mobility within and between RATs, an external PDU session point interconnected with the DN 1304, and a branch point supporting multi-donor PDU sessions. The UPF 1302 can also perform packet routing and forwarding, packet inspection, user plane portion enforcement of policy rules, lawful packet interception (UP collection), traffic usage reporting, QoS processing on the user plane (e.g., packet filtering, gating, UL / DL rate enforcement), uplink traffic authentication (e.g., SDF-to-QoS flow mapping), transport-level packet marking in uplink and downlink, and downlink packet buffering and downlink data notification triggering. The UPF 1302 may include an uplink classifier to support routing traffic flows to the data network. The DN 1304 may represent various network operator services, Internet access, or third-party services. The DN 1304 may include, for example, an application server.

[0143] Figure 14 This is a block diagram illustrating a component 1400, according to some exemplary embodiments, capable of reading instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and capable of executing any or more of the methods discussed herein. Specifically, Figure 14 A schematic diagram of hardware resource 1402 is shown, which includes one or more processors 1406 (or processor cores), one or more memory / storage devices 1414, and one or more communication resources 1424, each of which is communicatively coupled via bus 1416. For implementations utilizing node virtualization (e.g., NFV), a hypervisor 1422 can be executed to provide an execution environment for one or more network slices / subslices to utilize hardware resource 1402.

[0144] Processor 1406 (e.g., a central processing unit (CPU), a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a digital signal processor (DSP) (such as a baseband processor), an application-specific integrated circuit (ASIC), a radio frequency integrated circuit (RFIC), another processor, or any suitable combination thereof) may include, for example, processor 1408 and processor 1410.

[0145] The memory / storage device 1414 may include main memory, disk storage devices, or any suitable combination thereof. The memory / storage device 1414 may include, but is not limited to, any type of volatile or non-volatile memory, such as dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state storage devices, etc.

[0146] Communication resource 1424 may include interconnect or network interface components or other suitable devices for communicating with one or more peripheral devices 1404 or one or more databases 1420 via network 1418. For example, communication resource 1424 may include wired communication components (e.g., for coupling via Universal Serial Bus (USB), cellular communication components, NFC components, etc. Components (e.g.) (low power consumption) Components and other communication components.

[0147] Instruction 1412 may include software, programs, applications, applets, or other executable code for causing at least one processor in processor 1406 to perform any or more of the methods discussed herein. Instruction 1412 may reside wholly or partially within at least one processor in processor 1406 (e.g., within the processor's cache memory), memory / storage device 1414, or any suitable combination thereof. Furthermore, any portion of instruction 1412 may be transferred from peripheral device 1404 or database 1420 to hardware resource 1402. Therefore, the memory of processor 1406, memory / storage device 1414, peripheral device 1404, and database 1420 are examples of computer-readable and machine-readable media.

[0148] For one or more embodiments, at least one of the components shown in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, and / or methods described in the Embodiments section below. For example, the baseband circuitry described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples below. As another example, circuitry associated with the UE, base station, network element, etc., described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples shown in the Examples section below.

[0149] Example Section

[0150] The following examples relate to other implementation schemes.

[0151] Example 1 is a method for a user equipment (UE), the method comprising: receiving one of a notification request and a mobile station called (MT) paging from a network; determining that a protocol data unit (PDU) session previously available at the UE is no longer available at the UE; determining that a registration request message indicating that the PDU session is no longer available at the UE has not been sent to the network; and based on the determination that the registration request message has not been sent to the network, sending to the network a message including a PDU session state information element (IE), the PDU session state IE indicating that the PDU session is no longer available at the UE.

[0152] Example 2 is the method according to Example 1, including that the message of the PDU session state IE is a service request message.

[0153] Example 3 is the method according to Example 1, including that the message of the PDU session state IE is a registration request message.

[0154] Example 4 is a method according to any one of Examples 1 to 3, wherein the determination that the PDU session is no longer available at the UE is based on the determination that the PDU session is currently not active at the UE.

[0155] Example 5 is a method according to any one of Examples 1 to 3, wherein determining that the PDU session is no longer available at the UE is based on determining that the PDU session has been deactivated at the UE.

[0156] Example 6 is a method according to any one of Examples 1 to 5, the method further comprising determining, based on receiving from the network a reply message corresponding to the message including the PDU session state IE, that the network has been informed that the PDU session is no longer available at the UE.

[0157] Example 7 is the method described according to Example 6, wherein the reply message is a service acceptance message.

[0158] Example 8 is the method according to Example 6, wherein the reply message is a registration acceptance message.

[0159] Example 9 is a method according to any one of Examples 1 to 5, the method further comprising: determining, based on the failure to receive a reply message from the network corresponding to the message including the PDU session state IE, that the network has not been notified that the PDU session is no longer available at the UE; and, based on the determination that the network has not been notified that the PDU session is no longer available at the UE, sending to the network a second message including a second PDU session state IE, the second PDU session state IE indicating that the PDU session is no longer available at the UE.

[0160] Example 10 is a method for a user equipment (UE), the method comprising: receiving one of a notification request and a mobile station called (MT) paging from a network; determining that a protocol data unit (PDU) session previously available at the UE is no longer available at the UE; determining that a registration request message indicating that the PDU session is no longer available at the UE has not been sent to the network; and, based on the determination that the registration request message has not been sent to the network, sending a PDU session release request message for the PDU session to the network.

[0161] Example 11 is a method for a user equipment (UE) comprising: determining that the UE has data to be transmitted to a network on an uplink (UL); detecting a change in the session state of a Protocol Data Unit (PDU) maintained by the UE; and, based on the determination that the UE has pending data for the UL and the detection of the change in the session state of the PDU maintained by the UE, sending to the network a message including a PDU session state information element (IE), the PDU session state IE indicating the PDU session state maintained by the UE.

[0162] Example 12 is the method according to Example 11, including that the message of the PDU session state IE is a service request message.

[0163] Example 13 is the method according to Example 11, including that the message of the PDU session state IE is a registration request message.

[0164] Example 14 is a method according to any one of Examples 11 to 13, the method further comprising determining, based on receiving from the network a reply message corresponding to the message including the PDU session state IE, that the network has received the PDU session state maintained by the UE.

[0165] Example 15 is the method according to Example 14, wherein the reply message is a service acceptance message.

[0166] Example 16 is the method according to Example 14, wherein the reply message is a registration acceptance message.

[0167] Example 17 is a method according to any one of Examples 11 to 14, the method further comprising: determining, based on the failure to receive a reply message corresponding to the message including the PDU session state IE from the network, that the network has not yet received the PDU session state maintained by the UE; and based on the determination that the network has not yet received the PDU session state maintained by the UE, sending to the network a second message including a second PDU session state IE, the second PDU session state IE indicating the PDU session state maintained by the UE.

[0168] Example 18 is a method for access and mobility function (AMF) of a network, the method comprising: processing a service request message sent by a user equipment (UE) to the network, the service request message indicating that one or more protocol data unit (PDU) sessions are active at the UE; determining, based on PDU session states maintained at the AMF, that the one or more PDU sessions active at the UE are active at the network; and in response to the determination that the one or more PDU sessions active at the UE are active at the network, generating a service acceptance message that does not include a PDU session state information element (IE).

[0169] Example 19 is a method for a user equipment (UE), the method comprising: sending a service request message to a network containing a first PDU session state information element (IE), the service request message indicating that one or more protocol data unit (PDU) sessions are active at the UE; receiving a service acceptance message from the network in response to the service request message; determining that the service acceptance message from the network does not contain any PDU session state IE; and determining, based on the determination that the service acceptance message from the network does not contain any PDU session state IE, that the one or more PDU sessions active at the UE are active at the network.

[0170] Example 20 is a method for access and mobility function (AMF) of a network, the method comprising: detecting a lower-layer fault at the AMF; determining that the network did not send a reply message corresponding to a message including a PDU session state IE received from a UE at the network prior to the lower-layer fault; determining, based on the determination that the network did not send the reply message prior to the lower-layer fault, that the PDU session state maintained by the AMF has not been indicated to the UE; and, based on the determination that the PDU session state maintained by the AMF has not been indicated to the UE, sending a second message including the PDU session state IE to the UE, the PDU session state IE indicating the PDU session state maintained by the AMF.

[0171] Example 21 is a method for a user equipment (UE), the method comprising: receiving from a network an indication of establishing a data radio bearer (DRB) with the network; determining that the DRB corresponds to a protocol data unit (PDU) session that is not active at the UE; and in response to determining that the DRB corresponds to a PDU session that is not active at the UE, sending to the network a message including a PDU session state information element (IE), the PDU session state IE indicating that the PDU session is not active at the UE.

[0172] Example 22 is the method according to Example 21, wherein the UE: is in 5GMM-CONNECTED mode; and has an RRC inactivity indication.

[0173] Example 23 is a method according to any one of Examples 21 and 22, wherein the message of the PDU session state IE is a service request message.

[0174] Example 24 is a method according to any one of Examples 21 and 22, wherein the message of the PDU session state IE is a registration request message, and wherein in response to determining that the DRB corresponds to the PDU session that is not active at the UE, the UE does not send a service request message including the PDU session state IE.

[0175] Example 25 may include an apparatus comprising means for performing one or more elements of the method described or associated with any of the above embodiments or any other method or process described herein.

[0176] Example 26 may include one or more non-transitory computer-readable media, the one or more non-transitory computer-readable media including instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of the method or any other method or process described herein as described or associated with any of the above embodiments.

[0177] Example 27 may include an apparatus comprising one or more elements of a logic component, module, or circuit for performing any of the methods described or associated with any of the above embodiments or any other methods or processes described herein.

[0178] Example 28 may include any of the methods, techniques, or processes described or associated with any of the above examples, or any part or component thereof.

[0179] Example 29 may include an apparatus comprising one or more processors and one or more computer-readable media, the one or more computer-readable media including instructions that, when executed by the one or more processors, cause the one or more processors to perform any of the methods, techniques, or processes or portions thereof described or associated with any of the above embodiments.

[0180] Example 30 may include any signal or part or component thereof described or associated with any of the above examples.

[0181] Example 31 may include datagrams, packets, frames, segments, protocol data units (PDUs) or messages or parts or components thereof described or associated with any of the above examples, or otherwise described in this disclosure.

[0182] Example 32 may include a data-encoded signal or part or component thereof described or associated with any of the above examples, or otherwise described in this disclosure.

[0183] Example 33 may include a signal or part or component thereof encoded as a datagram, packet, frame, segment, PDU or message as described or associated with any of the above examples, or otherwise described in this disclosure.

[0184] Example 34 may include an electromagnetic signal carrying computer-readable instructions, wherein execution of the computer-readable instructions by one or more processors will cause one or more processors to perform any of the methods, techniques, or processes or portions thereof described or associated with any of the above examples.

[0185] Example 35 may include a computer program comprising instructions, wherein execution of the program by a processing element will cause the processing element to perform any of the methods, techniques, or processes or portions thereof described in or associated with any of the above embodiments.

[0186] Example 36 may include signals in a wireless network as shown and described herein.

[0187] Example 37 may include methods for communicating in a wireless network as shown and described herein.

[0188] Example 38 may include a system for providing wireless communication as shown and described herein.

[0189] Example 39 may include a device for providing wireless communication as shown and described herein.

[0190] Unless otherwise expressly stated, any of the above embodiments may be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more specific embodiments provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise forms disclosed. In view of the teachings above, modifications and variations are possible, or modifications and variations may be obtained from the practice of various embodiments.

[0191] Implementations and specific embodiments of the systems and methods described herein may include various operations embodied in machine-executable instructions to be executed by a computer system. The computer system may include one or more general-purpose or special-purpose computers (or other electronic devices). The computer system may include hardware components, including specific logical components for performing the operations, or may include a combination of hardware, software, and / or firmware.

[0192] It should be recognized that the systems described herein include descriptions of specific implementations. These implementations may be combined into a single system, partially integrated into other systems, divided into multiple systems, or otherwise partitioned or combined. Furthermore, it is conceivable to use parameters, attributes, aspects, etc., of one implementation in another implementation. For clarity, these parameters, attributes, aspects, etc., are described only in one or more implementations, and it should be recognized that unless specifically stated herein, these parameters, attributes, aspects, etc., may be combined with or substituted for parameters, attributes, aspects, etc., of another implementation.

[0193] As is widely recognized, the use of personally identifiable information should comply with privacy policies and practices that are generally accepted to meet or exceed industry or governmental requirements for protecting user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly explained to users.

[0194] Although the foregoing has been described in considerable detail for clarity, it will be apparent that certain changes and modifications can be made without departing from the principles of the invention. It should be noted that many alternative ways exist to implement both the processes and apparatus described herein. Therefore, embodiments of the invention should be considered illustrative rather than restrictive, and this specification is not limited to the details given herein, but can be modified within the scope of the appended claims and their equivalents.

Claims

1. A method for equipping a user (UE), the method comprising: One of receiving a notification request from the network and being paging a mobile station (MT); It was determined that a Protocol Data Unit (PDU) session previously available at the UE is no longer available at the UE. It has been determined that the registration request message indicating that the PDU session is no longer available at the UE has not been sent to the network; as well as Based on the determination that the registration request message has not yet been sent to the network, a message including a PDU session state information element (IE) is sent to the network, wherein the PDU session state IE indicates that the PDU session is no longer available at the UE.

2. The method of claim 1, wherein the message of the PDU session state IE is a service request message.

3. The method according to claim 1, wherein the message of the PDU session state IE is the registration request message.

4. The method of claim 1, wherein determining that the PDU session is no longer available at the UE is based on determining that the PDU session is currently not active at the UE.

5. The method of claim 1, wherein determining that the PDU session is no longer available at the UE is based on determining that the PDU session has been deactivated at the UE.

6. The method of claim 1, further comprising determining, based on receiving from the network a reply message corresponding to the message including the PDU session state IE, that the network has been informed that the PDU session is no longer available at the UE.

7. The method of claim 6, wherein the reply message is a service acceptance message.

8. The method according to claim 6, wherein the reply message is a registration acceptance message.

9. The method according to claim 1, further comprising: Based on the failure to receive a reply message from the network corresponding to the message including the PDU session state IE, it is determined that the network has not been informed that the PDU session is no longer available at the UE; as well as Based on the determination that the network has not been notified that the PDU session is no longer available at the UE, a second message including a second PDU session state IE is sent to the network, the second PDU session state IE indicating that the PDU session is no longer available at the UE.

10. A method for equipping a user (UE), the method comprising: One of receiving a notification request from the network and being paging a mobile station (MT); It was determined that a Protocol Data Unit (PDU) session previously available at the UE is no longer available at the UE. It has been determined that the registration request message indicating that the PDU session is no longer available at the UE has not been sent to the network; Based on the determination that the registration request message has not yet been sent to the network, a PDU session release request message for the PDU session is sent to the network.

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