Patent Description:
Third generation partnership project (3GPP) and <NUM> New Radio (NR) mobile telecommunication systems provide high data rate, lower latency and improved system performances. In 3GPP NR, <NUM> terrestrial New Radio (NR) access network (includes a plurality of base stations, e.g., Next Generation Node-Bs (gNBs), communicating with a plurality of mobile stations referred as user equipment (UEs). Orthogonal Frequency Division Multiple Access (OFDMA) has been selected for NR downlink radio access scheme due to its robustness to multipath fading, higher spectral efficiency, and bandwidth scalability. Multiple access in the downlink is achieved by assigning different sub-bands (i.e., groups of subcarriers, denoted as resource blocks (RBs)) of the system bandwidth to individual users based on their existing channel condition.

Multimedia Priority Service (MPS) has been developed to provide special high-priority access with a very selective group of users in mind and applies to the end-to-end session. The target users are usually authorized government, security, and special service users who need to be able to maintain communications via public mobile networks during special situations where public safety and security may be at risk. Such assignment is only allowed by regional/national authorities and is done through the mobile operator subscription mechanism with support for a special subscription profile for Multimedia Priority Service. In reality, the benefit of an MPS user is seen during adverse situations like natural disasters, security threats, etc. coinciding with possible failure of any possible private networks that may be otherwise used for priority/emergency communication by authorities. Since reserving a certain network capacity for this type of usage takes away possible service availability from regular users for that PLMN operator, there may be a limit depending on the situation and regional/local regulations on how much of the traffic volume can be reserved for MPS usage.

An MPS service user can benefit from a 3GPP system compared to a normal user. A system that supports MPS is able to provide end-to-end priority access to that MPS service user according to the level of priority assigned by the appropriate authority in situations like congestion or special disaster events. This is indicated by the MPS priority level.

Similar to MPS, Mission Critical Service (MCS) has been developed to provide special high-priority access with a very selective group of users in mind and applies to the end-to-end session. An MCS service user can benefit from a 3GPP system compared to a normal user. A system that supports MCS is able to provide end-to-end priority access to that MCS service user according to the level of priority assigned by the appropriate authority. This is indicated by the MCS priority level.

The MPS indicator (i.e., Access identity <NUM> is valid or not) and MCS indicator (i.e., Access identity <NUM> is valid or not) is applicable commonly to 3GPP and non-3GPP access. When the UE is registered to different NW (PLMN(s) or SNPN(s)) over 3GPP access and non-3GPP access, the MPS/MCS indicators included in the latest registration procedure (or configuration update procedure) over the first access will be applied also to second access, which is not an appropriate behavior.

The <NPL>", relates to determining UE access identity in several cases, e.g. MTSI MO speech call/SMSoIP (section <NUM>. <NUM>), Paging for MT Access/Emergency Call (section <NUM>. <NUM>), New cell not in the country of its HPLMN (section <NUM>. <NUM>), High Priority Access (section <NUM>. In all of these cases, validity of the Access Identity <NUM> and Access Identity <NUM> are evaluated, wherein the UE receives the 5GS network feature support IE with the MPS indicator bit set to "Access identity <NUM> valid" and <NUM> the UE receives the 5GS network feature support IE with the MCS indicator bit set to "Access identity <NUM> valid" from the PLMN. 3GPP and non-3GPP access are also considered. "Registration Accept" messages are used.

A method and a user equipment according to the invention are defined in the independent claims. The dependent claims define preferred embodiments thereof. A method of determining UE access identity for a UE that is registered to the same or different PLMN networks over 3GPP and non-3GPP accesses is proposed. The UE registers to one or more Public Land Mobile Network (PLMN) or Standalone Non-Public Network (SNPN) over 3GPP access and non-3GPP access. If the UE registers to the same PLMN/SNPN over 3GPP and non-3GPP access, then the UE handles the UE access identity as one common parameters. On the other hand, if the UE registers to different PLMN/SNPN over 3GPP and non-3GPP, then the UE handles the UE access identity as two independent parameters. The access identity may comprise a priority indicator IE that is set to "Access Identity <NUM> valid" or "Access Identity <NUM> invalid" for MPS, or "Access Identity <NUM> valid" or "Access Identity <NUM> invalid" for MCS.

In one example, if the UE receives a CONFIGURATION UPDATE COMMAND or REGISTRATION ACCEPT message with the MPS indicator bit in the Priority indicator IE set to "Access identity <NUM> valid" from a network via 3GPP access or via non-3GPP access if the UE is registered to the same PLMN or SNPN over 3GPP access and non-3GPP access, then the UE shall act as a UE with access identity <NUM> configured for MPS, in all NG-RAN of the registered PLMN or in the case of SNPN in all NG-RAN of the registered SNPN. In another example, if the UE receives a CONFIGURATION UPDATE COMMAND or REGISTRATION ACCEPT message with the MPS indicator bit in the Priority indicator IE set to "Access identity <NUM> valid" from a network via non-3GPP access or via 3GPP access if the UE is registered to the same PLMN or SNPN over 3GPP access and non-3GPP access, then the UE shall act as a UE with access identity <NUM> configured for MPS, in non-3GPP access of the registered PLMN or in the case of SNPN, in non-3GPP access of the registered SNPN.

In one embodiment, a UE maintains a first access identity, wherein the UE is registered to a first network via a first access type. The UE receives a REGISTRATION ACCEPT or a CONFIGURATION UPDATE COMMAND message over a second access type from a second network, wherein the message carries a second access identity. The UE uses the first access identity to determine a first access priority for accessing the first network when the first network and the second network are different networks, otherwise, the UE uses the second access identity to determine a second access priority for accessing the first network when the first network and the second network are same.

Other embodiments and advantages are described in the detailed description below. This summary does not purport to define the invention.

The accompanying drawings, where like numerals indicate like components, illustrate embodiments of the invention.

<FIG> illustrates an exemplary <NUM> network and a method of determining access identity when a User Equipment (UE) is registered to the same or different networks over 3GPP access and non-3GPP access in accordance with one novel aspect. <NUM> new radio (NR) network <NUM> comprises a user equipment (UE) <NUM>, a 3GPP access <NUM> (e.g., a 3GPP radio access network (RAN)), a non-3GPP access <NUM> (e.g., a non-3GPP RAN), an access and mobility management function (AMF) <NUM>, a session management function (SMF) <NUM>, a non-3GPP interworking function (N3IWF) <NUM>, a user plane function (UPF) <NUM>, and a <NUM> core (5GC) data network <NUM>. The AMF <NUM> communicates with the base stations in the 3GPP access <NUM>, the SMF <NUM>, and the UPF <NUM> for access and mobility management of wireless access devices in the <NUM> network <NUM>. The SMF <NUM> is primarily responsible for interacting with the decoupled data plane, creating, updating, and removing PDU sessions and managing session context with the UPF <NUM>. The N3IWF <NUM> interfaces to <NUM> core network control plane functions, responsible for routing messages outside <NUM> RAN.

In Access Stratum (AS) layer, an RAN provides radio access for the UE <NUM> via a radio access technology (RAT). In Non-Access Stratum (NAS) layer, the AMF <NUM> and the SMF <NUM> communicate with RAN and 5GC for access and mobility management and PDU session management of wireless access devices in the <NUM> network <NUM>. The 3GPP access <NUM> may include base stations (gNBs or eNBs) providing radio access for the UE <NUM> via various 3GPP RATs including <NUM>, <NUM>, and <NUM>/<NUM>. The non-3GPP access <NUM> may include access points (APs) providing radio access for the UE <NUM> via non-3GPP RAT including WiFi. The UE <NUM> can obtain access to data network <NUM> through 3GPP access <NUM>, AMF <NUM>, SMF <NUM>, and UPF <NUM>. The UE <NUM> can obtain access to data network <NUM> through non-3GPP access <NUM>, N3IWF <NUM>, AMF <NUM>, SMF <NUM>, and UPF <NUM>. The UE <NUM> may be equipped with a single radio frequency (RF) module or transceiver or multiple RF modules or transceivers for services via different RATs/CNs. In some examples, UE <NUM> may be a smart phone, a wearable device, an Internet of Things (IoT) device, a tablet, etc..

A PDU session defines the association between the UE and the data network that provides a PDU connectivity service. Each PDU session is identified by a PDU session ID, and can be established over a 3GPP RAN, and/or over a non-3GPP RAN. <NUM> session management (5GSM) for PDU sessions over both 3GPP access and non-3GPP access are managed by AMF and SMF via NAS signaling. Multimedia Priority Service (MPS) has been developed to provide special high-priority access with a very selective group of users in mind and applies to the end-to-end session. A system that supports MPS is able to provide end-to-end priority access to that MPS service user according to the level of priority assigned by the appropriate authority. Similar to MPS, Mission Critical Service (MCS) has been developed to provide special high-priority access with a very selective group of users in mind and applies to the end-to-end session. A system that supports MCS is able to provide end-to-end priority access to that MCS service user according to the level of priority assigned by the appropriate authority.

The prioritized MPS/MCS can be indicated by the MPS/MCS priority level via UE access identity. In the example of <FIG>, UE <NUM> knows it is configured for MPS, i.e., Access identity <NUM> valid: <NUM>) if in the USIM file EFUAC_AIC indicates the UE is configured for access identity <NUM>, or <NUM>) if the UE receives REGISTRATION ACCEPT message or CONFIGURATION UPDATE COMMAND message with the MPS indicator bit set is to "Access identity <NUM> valid". Then, UE <NUM> determines: it is configured for multimedia priority service (MPS), i.e., Access identity <NUM> valid. Similarly, UE <NUM> knows it is configured for MCS, i.e., Access identity <NUM> valid: <NUM>) if in the USIM file EFUAC_AIC indicates the UE is configured for access identity <NUM>, or <NUM>) if the UE receives REGISTRATION ACCEPT message or CONFIGURATION UPDATE COMMAND message with the MCS indicator bit set is to "Access identity <NUM> valid". Then, UE <NUM> determines: it is configured for mission critical service (MCS), i.e., Access identity <NUM> valid. The MPS indicator (i.e., Access identity <NUM> is valid or not) and MCS indicator (i.e., Access identity <NUM> is valid or not) is applicable commonly to 3GPP and non-3GPP access. When the UE is registered to both a 3GPP access and a non-3GPP access, it is undefined how the UE should determine the UE access identity obtained over 3GPP access or non-3GPP access.

In accordance with one novel aspect, a method of determining access identity when UE is registered to the same or different PLMN/SNPN over 3GPP/non-3GPP is proposed. When the UE is registered to the same PLMN or SNPN over 3GPP and non-3GPP access, the UE and the AMF maintain one MPS indicator and one MCS indicator that are common to both 3GPP and non-3GPP access. When the UE is registered to different PLMNs or SNPNs over 3GPP access and non-3GPP access, the UE maintains two MPS indicators and two MCS indicators separately for different accesses i.e., a MPS indicator and a MCS indicator for the 3GPP access and another MPS indicator and a MCS indicator for the non-3GPP access. As depicted in <FIG> (<NUM>), UE <NUM> registers to one or more Public Land Mobile Network (PLMN) or Standalone Non-Public Network (SNPN) over 3GPP access and non-3GPP access and receives UE access identity via a CONFIGURATION UPDATE COMMAND message or a REGISTRATION ACCEPT message. If UE <NUM> registers to the same PLMN/SNPN over 3GPP and non-3GPP access, then UE <NUM> handles the UE access identity as one common parameters (<NUM>). On the other hand, if UE <NUM> registers to different PLMN/SNPN over 3GPP and non-3GPP, then UE <NUM> handles the UE access identity as two independent parameters (<NUM>).

<FIG> illustrates simplified block diagrams of wireless devices, e.g., a UE <NUM> and a network entity <NUM> in accordance with embodiments of the current invention. Network entity <NUM> may be a base station and/or an AMF/SMF. Network entity <NUM> has an antenna <NUM>, which transmits and receives radio signals. A radio frequency RF transceiver module <NUM>, coupled with the antenna, receives RF signals from antenna <NUM>, converts them to baseband signals and sends them to processor <NUM>. RF transceiver <NUM> also converts received baseband signals from processor <NUM>, converts them to RF signals, and sends out to antenna <NUM>. Processor <NUM> processes the received baseband signals and invokes different functional modules to perform features in base station <NUM>. Memory <NUM> stores program instructions and data <NUM> to control the operations of base station <NUM>. In the example of <FIG>, network entity <NUM> also includes protocol stack <NUM> and a set of control function modules and circuits <NUM>. Protocol stacks <NUM> includes Non-Access-Stratum (NAS) layer to communicate with an AMF/SMF/MME entity connecting to the core network, Radio Resource Control (RRC) layer for high layer configuration and control, Packet Data Convergence Protocol/Radio Link Control (PDCP/RLC) layer, Media Access Control (MAC) layer, and Physical (PHY) layer. In one example, control function modules and circuits <NUM> includes a registration circuit <NUM> that handles registration procedures, a connection handling circuit <NUM> that handles signaling connections, and a configuration and control circuit <NUM> that provides different parameters to configure and control UE of related functionalities including registration and paging. The network entity <NUM> can be one 5GS network component or more than one 5GS network components (e.g., access network + AMF + N3IWF + SMF, etc.).

Similarly, UE <NUM> has memory <NUM>, a processor <NUM>, and radio frequency (RF) transceiver module <NUM>. RF transceiver <NUM> is coupled with antenna <NUM>, receives RF signals from antenna <NUM>, converts them to baseband signals, and sends them to processor <NUM>. RF transceiver <NUM> also converts received baseband signals from processor <NUM>, converts them to RF signals, and sends out to antenna <NUM>. Processor <NUM> processes the received baseband signals and invokes different functional modules and circuits to perform features in UE <NUM>. Memory <NUM> stores data and program instructions <NUM> to be executed by the processor to control the operations of UE <NUM>. Suitable processors include, by way of example, a special purpose processor, a digital signal processor (DSP), a plurality of micro-processors, one or more micro-processor associated with a DSP core, a controller, a microcontroller, application specific integrated circuits (ASICs), file programmable gate array (FPGA) circuits, and other type of integrated circuits (ICs), and/or state machines. A processor in associated with software may be used to implement and configure features of UE <NUM>.

UE <NUM> also includes protocol stacks <NUM> and a set of control function modules and circuits <NUM>. Protocol stacks <NUM> includes NAS layer to communicate with an AMF/SMF/MME entity connecting to the core network, RRC layer for high layer configuration and control, PDCP/RLC layer, MAC layer, and PHY layer. Control function modules and circuits <NUM> may be implemented and configured by software, firmware, hardware, and/or combination thereof. The control function modules and circuits, when executed by the processors via program instructions contained in the memory, interwork with each other to allow UE <NUM> to perform embodiments and functional tasks and features in the network. In one example, control function modules and circuits <NUM> includes a registration handling circuit <NUM> that performs registration procedure with the network, an access and connection handling circuit <NUM> that handles RRC and NAS signaling connection, and a config and control circuit <NUM> that handles configuration and control parameters including determining UE access identity.

<FIG> illustrates a mapping table for access identities or access categories and RRC establishment cause for 3GPP access. There are two ways to make the MPS access different (higher priority) than others. First, in UAC (Unified Access Control) mechanism, the UE with Access identity <NUM> is treated separately (operator can configure not to bar the access at all). Second, a separate dedicated RRC establishment cause "mps-PriorityAccess" is used so the network can prioritize this kind of access. Similarly, there are two ways to make the MCS access different (higher priority) than others. First, in UAC mechanism, the UE with Access identity <NUM> is treated separately (operator can configure not to bar the access at all). Second, a separate dedicated RRC establishment cause "mcs-PriorityAccess" is used so the network can prioritize this kind of access.

<FIG> illustrates a mapping table for access identities and determination of establishment cause for non-3GPP access. Although UAC is only applicable to 3GPP access (NG-RAN), the establishment cause "mps-PriorityAccess" is applicable to both 3GPP and non-3GPP access, and the establishment cause "mcs-PriorityAccess" is applicable to both 3GPP and non-3GPP access. In one example, UE receives a CONFIGURATION UPDATE COMMAND message, or a REGISTRATION ACCEPT message with the MPS indicator bit in the Priority indicator IE set to "Access identity <NUM> valid" over non-3GPP access. In another example, UE receives a CONFIGURATION UPDATE COMMAND message, or a REGISTRATION ACCEPT message with the MCS indicator bit in the Priority indicator IE set to "Access identity <NUM> valid" over non-3GPP access.

<FIG> illustrates one embodiment of UE access identity determination when a UE is registered to the same network over 3GPP access and non-3GPP access in accordance with one novel aspect. In step <NUM>, UE <NUM> registers to PLMN1 by sending a REGISTRATION REQUEST message over 3GPP access <NUM> or over non-3GPP access <NUM>, the request message carries UE-Requested access identity information. In step <NUM>, UE <NUM> receives a REGISTRATION ACCEPT message over 3GPP or non-3GPP access, the accept message carries UE access identity information, e.g., a first priority indicator IE. In step <NUM>, UE <NUM> starts to apply the first priority indicator IE, e.g., act as being configured for "Access identity <NUM> valid" (MPS) in all NG-RAN of the registered PLMN1. For example, UE <NUM> sets the establishment cause to "mps-priority access" in a subsequent RRC setup request message when UE <NUM> accesses PLMN1 via NG-RAN.

In step <NUM>, UE <NUM> receives a CONFIGURATION UPDATE COMMAND message from PLMN1 over 3GPP access <NUM> or over non-3GPP access <NUM>, carrying UE access identity information, e.g., a second priority indicator IE. UE <NUM> then determines whether the UE is registered to the same or different PLMN/SNPN over 3GPP access and non-3GPP access. In the example of <FIG>, UE <NUM> is registered to the same PLMN1 over 3GPP access <NUM> and non-3GPP access <NUM>. Therefore, UE <NUM> handles the access identity for both 3GPP access and non-3GPP access as a common parameter. In another word, UE <NUM> handles and applies a common access priority, regardless of whether UE <NUM> receives the access identity information over 3GPP access or non-3GPP access. As a result, in step <NUM>, UE <NUM> stores the second access identity information, and applies the second priority indicator IE, e.g., act as being configured for "Access identity <NUM> not valid" in all NG-RAN of the registered PLMN1. For example, in step <NUM>, UE <NUM> performs RRC connection setup procedure over 3GPP access, and sets the establishment cause to "Access identity <NUM> not valid" in the RRC setup request message when UE <NUM> accesses PLMN1 via NG-RAN. In step <NUM>, UE <NUM> performs a NAS signaling connection setup procedure over non-3GPP access, and applies "Access identity <NUM> not valid" when UE <NUM> accesses PLMN1 over non-3GPP.

<FIG> illustrates one embodiment of UE access identity determination when a UE is registered to different networks over 3GPP access and non-3GPP access in accordance with one novel aspect. In step <NUM>, UE <NUM> registers to PLMN1 by sending a REGISTRATION REQUEST message over 3GPP access <NUM>, the request message carries UE-Requested access identity information. In step <NUM>, UE <NUM> receives a REGISTRATION ACCEPT message over 3GPP access, the accept message carries UE access identity information, e.g., a first priority indicator IE. In step <NUM>, UE <NUM> receives a CONFIGURATION UPDATE COMMAND message from PLMN2 over non-3GPP access <NUM>, carrying a second UE access identity information, e.g., a second updated priority indicator IE with access priority level.

UE <NUM> then determines whether the UE is registered to the same or different PLMN/SNPN over 3GPP access and non-3GPP access. In the example of <FIG>, UE <NUM> is registered to PLMN1 over 3GPP access <NUM> and is registered to PLMN2 over non-3GPP access <NUM>. Therefore, UE <NUM> handles the UE access identity for 3GPP access and non-3GPP access as two independent sets of parameters. In another word, UE <NUM> handles and uses two independent access identity information, depending on whether UE <NUM> receives the access identity information from 3GPP access or from non-3GPP access. As a result, in step <NUM>, UE <NUM> starts to apply the first priority indicator IE, e.g., act as being configured for "Access identity <NUM> valid" (MPS) in all NG-RAN of the registered PLMN1. For example, in step <NUM>, UE <NUM> sets the establishment cause to "mps-priority access" in a subsequent RRC setup request message when UE <NUM> accesses PLMN1 via NG-RAN. On the other hand, in step <NUM>, UE <NUM> starts to apply the second priority indicator IE, e.g., act as being configured for "Access identity <NUM> not valid" over non-3GPP of the registered PLMN2. For example, in step <NUM>, UE <NUM> sets "Access identity <NUM> not valid" in a subsequent NAS signaling message when UE <NUM> accesses PLMN2 over non-3GPP.

<FIG> is a flow chart of a method of determining UE access identity in accordance with one novel aspect of the present invention. In step <NUM>, a UE maintains a valid first access identity, wherein the UE is registered to a first network via a first access type. In step <NUM>, the UE receives a REGISTRATION ACCEPT or a CONFIGURATION UPDATE COMMAND message over a second access type from a second network, wherein the message carries an indicator indicating the first access identity is not valid. In step <NUM>, the UE considers the first access identity is valid when determining a first establishment cause for accessing the first network via the first access type when the first network and the second network are different networks, otherwise, the UE considers the first access identity is not valid when determining a second establishment cause for accessing the first network via the first access type when the first network and the second network are same network.

Claim 1:
A method, comprising:
maintaining a valid first access identity by a User Equipment, in the following also referred to as UE, wherein the UE is registered to a first network via a first access type (<NUM>);
receiving a REGISTRATION ACCEPT or a CONFIGURATION UPDATE COMMAND message over a second access type from a second network, wherein the message carries an indicator indicating the first access identity is not valid (<NUM>); and
considering the first access identity is valid when determining a first establishment cause for accessing the first network via the first access type when the first network and the second network are different networks (<NUM>), otherwise,
considering the first access identity is not valid when determining a second establishment cause for accessing the first network via the first access type when the first network and the second network are same network (<NUM>).