Patent Description:
Wireless communication systems are rapidly growing in usage. In recent years, wireless devices such as smart phones and tablet computers have become increasingly sophisticated. Wireless devices such as smart phones support telephony and in addition provide access to the Internet, email, text messaging, and navigation using the global positioning system (GPS), and are capable of operating sophisticated applications that utilize these functionalities.

Some examples of wireless communication standards include GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE Advanced (LTE-A), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), IEEE <NUM> (WLAN or Wi-Fi), IEEE <NUM> (WiMAX), Bluetooth, and others.

Long Term Evolution (LTE) is a fairly recent standard that is supported by the majority of wireless network operators worldwide, providing mobile broadband data and high-speed Internet access to their subscriber base. LTE defines a number of downlink (DL) physical channels, categorized as transport or control channels, to carry information blocks received from medium access control (MAC) and higher layers. LTE also defines a number of physical layer channels for the uplink (UL).

A proposed next telecommunications standard moving beyond the current International Mobile Telecommunications-Advanced (IMT-Advanced) Standards is called 5th generation mobile networks or 5th generation wireless systems, or <NUM> for short (otherwise known as <NUM>-NR for <NUM> New Radio, also simply referred to as NR). <NUM>-NR proposes a higher capacity for a higher density of mobile broadband users, also supporting device-to-device, ultra-reliable, and massive machine communications, as well as lower latency and lower battery consumption, than current LTE standards. Further, the <NUM>-NR standard may allow for less restrictive UE scheduling as compared to current LTE standards. Consequently, efforts are being made in ongoing developments of <NUM>-NR to take advantage of higher throughputs possible at higher frequencies.

As demand for wireless communication systems grows and new use cases for wireless communication arise, there is a seemingly continual need to develop next generation wireless communication techniques and standards. One such developing concept may include network slicing, which may allow a network operator to create different "network slices" configured to address different wireless communication use cases and scenarios in a customized manner.

<CIT> describes a communication device for handling a packet data network (PDN) connection and a network slice comprises at least one storage device; and at least one processing circuit, coupled to the at least one storage device.

<CIT> describes provisioning and enforcement of network slice information in a communication network.

Embodiments relate to wireless communications, and more particularly to apparatuses and methods for a user equipment device (UE) to provide slice related information to a first cellular network that does not support network slicing. This slice related information may assist the network in providing the appropriate network slice selection assistance information (NSSAI) to the UE for use during subsequent inter RAT transfers to a different cellular network that does support network slicing.

A user equipment (UE) may comprise a radio, one or more antennas, and a processor. The UE may be configured to initiate an application on the UE while connected with a first cellular network, wherein the first cellular network may not support network slicing. The UE may then determine slice related information for the application, and provide the slice related information to the first cellular network, such as in a PDN Connectivity Request. The slice related information may comprise a proposed S-NSSAI, or alternatively may comprise an identifier of a specific network slice customer (NSC). The first cellular network may use the slice related information to determine an "appropriate" or "correct" S-NSSAI to provide back to the UE. The UE may then receive this "correct" S-NSSAI from the first cellular network, wherein the "correct" S-NSSAI was determined based at least in part on the slice related information provided by the UE to the first cellular network.

The S-NSSAI may be useable when the UE transitions to a second cellular network that does support network slicing. For example, the UE may transition from the first cellular network (e.g., a <NUM> Network) to a second cellular network (e.g., a <NUM> network) that supports network slicing. This transition may comprise a packet data unit (PDU) session between the UE and the second cellular network (e.g., where the PDN established in the <NUM> Network is mapped to a PDU session in the <NUM> Network). When this transition occurs, both the UE and the second cellular network may link the "correct" S-NSSAI (received from the first cellular network) with the PDU session between the UE and the second cellular network. This may provide an improved user experience.

A network device in the first cellular network may be configured to perform various of the first cellular network operations described above. For example, the network device may be configured to receive a packet data network (PDN) connectivity request message from the UE, wherein the PDN connectivity request message includes slice related information associated with a packet data protocol (PDP) context between the UE and the cellular network. The network device may then determine a "correct" single network slice selection assistance information (S-NSSAI) for the PDP context based at least in part on one or more of: <NUM>) the slice related information received from the UE; and/or <NUM>) core logic in the cellular network. The network device may then transmit the correct S-NSSAI to the UE, wherein the correct S-NSSAI is useable when UE transitions to a second cellular network that does support network slicing.

A UE may be configured to transmit a packet data network (PDN) connectivity request to a first cellular network, wherein the first cellular network does not support network slicing. The UE then may receive a message from the first cellular network, wherein the message comprises a list of a plurality of possible single network slice selection assistance information sets (S-NSSAIs). The UE may then select a desired S-NSSAI from the list of the plurality of possible S-NSSAIs. The selected S-NSSAI may be useable when the UE transitions from the first cellular network to a second cellular network that supports network slicing.

The UE may transmit the selected S-NSSAI to the first cellular network. When the UE moves to a second cellular network that supports network slicing, the UE may transmit the selected S-NSSAI to the second cellular network. The UE may transmit a Radio Resource Control (RRC) connection establishment message to the second cellular network, wherein the RRC connection establishment message comprises the selected S-NSSAI for use by the second cellular network. When the UE transitions from the first to the second cellular network, both the UE and the second cellular network may link the S-NSSAI received from the first cellular network with a PDU session between the UE and the second cellular network.

A network device in the first cellular network may be configured to perform various of the first cellular network operations described above. For example, the network device may be configured to receive a packet data network (PDN) connectivity request from a UE. The network device may then transmit a message to the UE comprising a list of a plurality of possible single network slice selection assistance information sets (S-NSSAIs). The network device may then receive a first S-NSSAI from the UE, wherein the first S-NSSAI is selected from the list of the plurality of possible S-NSSAIs. The first (selected) S-NSSAI is useable for when the UE transitions from the first cellular network to a second cellular network that supports network slicing.

The techniques described herein may be implemented in and/or used with a number of different types of devices, including but not limited to unmanned aerial vehicles (UAVs), unmanned aerial controllers (UACs), base stations, access points, cellular phones, tablet computers, wearable computing devices, portable media players, automobiles and/or motorized vehicles, and any of various other computing devices.

Specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to be limiting to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the scope of the subject matter as defined by the appended claims.

The following is a glossary of terms used in this disclosure:
Memory Medium - Any of various types of non-transitory memory devices or storage devices. The term "memory medium" is intended to include an installation medium, e.g., a CD-ROM, floppy disks, or tape device; a computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; a non-volatile memory such as a Flash, magnetic media, e.g., a hard drive, or optical storage; registers, or other similar types of memory elements, etc. The memory medium may include other types of non-transitory memory as well or combinations thereof. In addition, the memory medium may be located in a first computer system in which the programs are executed, or may be located in a second different computer system which connects to the first computer system over a network, such as the Internet. In the latter instance, the second computer system may provide program instructions to the first computer for execution. The term "memory medium" may include two or more memory mediums which may reside in different locations, e.g., in different computer systems that are connected over a network. The memory medium may store program instructions (e.g., embodied as computer programs) that may be executed by one or more processors.

Computer System (or Computer) - any of various types of computing or processing systems, including a personal computer system (PC), mainframe computer system, workstation, network appliance, Internet appliance, personal digital assistant (PDA), television system, grid computing system, or other device or combinations of devices. In general, the term "computer system" can be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

User Equipment (UE) (or "UE Device") - any of various types of computer systems devices which are mobile or portable and which performs wireless communications. Examples of UE devices include mobile telephones or smart phones (e.g., iPhone™, Android™-based phones), portable gaming devices (e.g., Nintendo DS™, PlayStation Portable™, Gameboy Advance™, iPhone™), laptops, wearable devices (e.g. smart watch, smart glasses), PDAs, portable Internet devices, music players, data storage devices, other handheld devices, automobiles and/or motor vehicles, unmanned aerial vehicles (UAVs) (e.g., drones), UAV controllers (UACs), and so forth. In general, the term "UE" or "UE device" can be broadly defined to encompass any electronic, computing, and/or telecommunications device (or combination of devices) which is easily transported by (or with) a user and capable of wireless communication.

Processing Element (or Processor) - refers to various elements or combinations of elements that are capable of performing a function in a device, such as a user equipment or a cellular network device. Processing elements may include, for example: processors and associated memory, portions or circuits of individual processor cores, entire processor cores, processor arrays, circuits such as an ASIC (Application Specific Integrated Circuit), programmable hardware elements such as a field programmable gate array (FPGA), as well any of various combinations of the above.

Various components may be described as "configured to" perform a task or tasks.

The communication area (or coverage area) of the base station may be referred to as a "cell. " The base station 102A and the UEs <NUM> may be configured to communicate over the transmission medium using any of various radio access technologies (RATs), also referred to as wireless communication technologies, or telecommunication standards, such as GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-Advanced (LTE-A), <NUM> new radio (<NUM> NR), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), etc. Note that if the base station 102A is implemented in the context of LTE, it may alternately be referred to as an 'eNodeB' or 'eNB'. Note that if the base station 102A is implemented in the context of <NUM> NR, it may alternately be referred to as 'gNodeB' or 'gNB'.

In some embodiments, base station 102A may be a next generation base station, e.g., a <NUM> New Radio (<NUM> NR) base station, or "gNB". In some embodiments, a gNB may be connected to a legacy evolved packet core (EPC) network and/or to a NR core (NRC) network. In addition, a gNB cell may include one or more transition and reception points (TRPs).

Note that a UE <NUM> may be capable of communicating using multiple wireless communication standards. For example, the UE <NUM> may be configured to communicate using a wireless networking (e.g., Wi-Fi) and/or peer-to-peer wireless communication protocol (e.g., Bluetooth, Wi-Fi peer-to-peer, etc.) in addition to at least one cellular communication protocol (e.g., GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-A, <NUM> NR, HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), etc.). The UE <NUM> may also or alternatively be configured to communicate using one or more global navigational satellite systems (GNSS, e.g., GPS or GLONASS), one or more mobile television broadcasting standards (e.g., ATSC-M/H or DVB-H), and/or any other wireless communication protocol, if desired. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible.

<FIG> illustrates user equipment <NUM> (e.g., one of the devices 106A through 106N) in communication with a base station <NUM> and an access point <NUM>, according to some embodiments. The UE <NUM> may be a device with both cellular communication capability and non-cellular communication capability (e.g., Bluetooth, Wi-Fi, and so forth) such as a mobile phone, a hand-held device, a computer or a tablet, or virtually any type of wireless device.

Alternatively, or in addition, the UE <NUM> may include a programmable hardware element such as an FPGA (fieldprogrammable gate array) that is configured to perform any of the method embodiments described herein, or any portion of any of the method embodiments described herein.

The UE <NUM> may include one or more antennas for communicating using one or more wireless communication protocols or technologies. In some embodiments, the UE <NUM> may be configured to communicate using, for example, CDMA2000 (1xRTT / 1xEV-DO / HRPD / eHRPD), LTE/LTE-Advanced, or <NUM> NR using a single shared radio and/or GSM, LTE, LTE-Advanced, or <NUM> NR using the single shared radio. The shared radio may couple to a single antenna, or may couple to multiple antennas (e.g., for MIMO) for performing wireless communications. In general, a radio may include any combination of a baseband processor, analog RF signal processing circuitry (e.g., including filters, mixers, oscillators, amplifiers, etc.), or digital processing circuitry (e.g., for digital modulation as well as other digital processing). Similarly, the radio may implement one or more receive and transmit chains using the aforementioned hardware. For example, the UE <NUM> may share one or more parts of a receive and/or transmit chain between multiple wireless communication technologies, such as those discussed above.

<FIG> illustrates an example simplified block diagram of a communication device <NUM>, according to some embodiments. It is noted that the block diagram of the communication device of <FIG> is only one example of a possible communication device. According to embodiments, communication device <NUM> may be a user equipment (UE) device, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop, notebook, or portable computing device), a tablet, an unmanned aerial vehicle (UAV), a UAV controller (UAC) and/or a combination of devices, among other devices. As shown, the communication device <NUM> may include a set of components <NUM> configured to perform core functions. For example, this set of components may be implemented as a system on chip (SOC), which may include portions for various purposes. Alternatively, this set of components <NUM> may be implemented as separate components or groups of components for the various purposes. The set of components <NUM> may be coupled (e.g., communicatively; directly or indirectly) to various other circuits of the communication device <NUM>.

For example, the communication device <NUM> may include various types of memory (e.g., including NAND Flash <NUM>), an input/output interface such as connector I/F <NUM> (e.g., for connecting to a computer system; dock; charging station; input devices, such as a microphone, camera, keyboard; output devices, such as speakers; etc.), the display <NUM>, which may be integrated with or external to the communication device <NUM>, and cellular communication circuitry <NUM> such as for <NUM> NR, LTE, GSM, etc., and short to medium range wireless communication circuitry <NUM> (e.g., Bluetooth™ and WLAN circuitry).

Note that the term "SIM" or "SIM entity" is intended to include any of various types of SIM implementations or SIM functionality, such as the one or more UICC(s) cards <NUM>, one or more eUICCs, one or more eSIMs, either removable or embedded, etc. In some embodiments, the UE <NUM> may include a combination of removable smart cards and fixed/non-removable smart cards (such as one or more eUICC cards that implement eSIM functionality), as desired. For example, the UE <NUM> may comprise two embedded SIMs, two removable SIMs, or a combination of one embedded SIMs and one removable SIMs. Various other SIM configurations are also contemplated.

In some embodiments, the UE <NUM> may include two or more SIMs. The inclusion of two or more SIMs in the UE <NUM> may allow the UE <NUM> to support two different telephone numbers and may allow the UE <NUM> to communicate on corresponding two or more respective networks. For example, a first SIM may support a first RAT such as LTE, and a second SIM <NUM> support a second RAT such as <NUM> NR. Other implementations and RATs are of course possible. In some embodiments, when the UE <NUM> comprises two SIMs, the UE <NUM> may support Dual SIM Dual Active (DSDA) functionality. The DSDA functionality may allow the UE <NUM> to be simultaneously connected to two networks (and use two different RATs) at the same time, or to simultaneously maintain two connections supported by two different SIMs using the same or different RATs on the same or different networks. The DSDA functionality may also allow the UE <NUM> to simultaneously receive voice calls or data traffic on either phone number. In certain embodiments the voice call may be a packet switched communication. In other words, the voice call may be received using voice over LTE (VoLTE) technology and/or voice over NR (VoNR) technology. In some embodiments, the UE <NUM> may support Dual SIM Dual Standby (DSDS) functionality. The DSDS functionality may allow either of the two SIMs in the UE <NUM> to be on standby waiting for a voice call and/or data connection. In DSDS, when a call/data is established on one SIM, the other SIM is no longer active. In some embodiments, DSDx functionality (either DSDA or DSDS functionality) may be implemented with a single SIM (e.g., a eUICC) that executes multiple SIM applications for different carriers and/or RATs.

As shown, the SOC <NUM> may include processor(s) <NUM>, which may execute program instructions for the communication device <NUM> and display circuitry <NUM>, which may perform graphics processing and provide display signals to the display <NUM>. The processor(s) <NUM> may also be coupled to memory management unit (MMU) <NUM>, which may be configured to receive addresses from the processor(s) <NUM> and translate those addresses to locations in memory (e.g., memory <NUM>, read only memory (ROM) <NUM>, NAND flash memory <NUM>) and/or to other circuits or devices, such as the display circuitry <NUM>, short to medium range wireless communication circuitry <NUM>, cellular communication circuitry <NUM>, connector I/F <NUM>, and/or display <NUM>. The MMU <NUM> may be configured to perform memory protection and page table translation or set up. In some embodiments, the MMU <NUM> may be included as a portion of the processor(s) <NUM>.

As noted above, the communication device <NUM> may be configured to communicate using wireless and/or wired communication circuitry. The communication device <NUM> may be configured to perform any of the various methods as further described herein.

As described herein, the communication device <NUM> may include hardware and software components for implementing the features described herein for a communication device <NUM> to communicate slice related information to the network. The processor <NUM> of the communication device <NUM> may be configured to implement part or all of the features described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively (or in addition), processor <NUM> may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit). Alternatively (or in addition) the processor <NUM> of the communication device <NUM>, in conjunction with one or more of the other components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be configured to implement part or all of the features described herein.

Further, as described herein, cellular communication circuitry <NUM> and short to medium range wireless communication circuitry <NUM> may each include one or more processing elements. In other words, one or more processing elements may be included in cellular communication circuitry <NUM> and, similarly, one or more processing elements may be included in short to medium range wireless communication circuitry <NUM>. Thus, cellular communication circuitry <NUM> may include one or more integrated circuits (ICs) that are configured to perform the functions of cellular communication circuitry <NUM>. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of cellular communication circuitry <NUM>. Similarly, the short to medium range wireless communication circuitry <NUM> may include one or more ICs that are configured to perform the functions of short to medium range wireless communication circuitry <NUM>. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of short to medium range wireless communication circuitry <NUM>.

<FIG> illustrates an exemplary block diagram of a network element <NUM>, according to some embodiments. According to some embodiments, the network element <NUM> may implement one or more logical functions/entities of a cellular core network, such as a mobility management entity (MME), serving gateway (S-GW), etc. As another possibility, the network element <NUM> may implement a network slice selection function (NSSF) entity. It is noted that the network element <NUM> of <FIG> is merely one example of a possible network element <NUM>. As shown, the core network element <NUM> may include processor(s) <NUM> which may execute program instructions for the core network element <NUM>.

The network element <NUM> may include at least one network port <NUM>. The network port <NUM> may be configured to couple to one or more base stations and/or other cellular network entities and/or devices. The network element <NUM> may communicate with base stations (e.g., eNBs) and/or other network entities / devices by means of any of various communication protocols and/or interfaces.

As described further subsequently herein, the network element <NUM> may include hardware and software components for implementing and/or supporting implementation of features described herein. The processor(s) <NUM> of the core network element <NUM> may be configured to implement or support implementation of part or all of the methods described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium).

<FIG> illustrates an example simplified block diagram of cellular communication circuitry, according to some embodiments. It is noted that the block diagram of the cellular communication circuitry of <FIG> is only one example of a possible cellular communication circuit. According to embodiments, cellular communication circuitry <NUM> may be included in a communication device, such as communication device <NUM> described above. As noted above, communication device <NUM> may be a user equipment (UE) device, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop, notebook, or portable computing device), a tablet and/or a combination of devices, among other devices.

The cellular communication circuitry <NUM> may couple (e.g., communicatively; directly or indirectly) to one or more antennas, such as antennas 335a-b and <NUM> as shown (in <FIG>). In some embodiments, cellular communication circuitry <NUM> may include dedicated receive chains (including and/or coupled to, e.g., communicatively; directly or indirectly. For example, as shown in <FIG>, cellular communication circuitry <NUM> may include a modem <NUM> and a modem <NUM>. Modem <NUM> may be configured for communications according to a first RAT, e.g., such as LTE or LTE-A, and modem <NUM> may be configured for communications according to a second RAT, e.g., such as <NUM> NR.

In some embodiments, the cellular communication circuitry <NUM> may be configured to perform methods a network to notify user equipment device (UE) whether a network slice the UE has requested is subject to a quota as further described herein.

As described herein, the modem <NUM> may include hardware and software components for implementing any of the various other techniques described herein. The processors <NUM> may be configured to implement part or all of the features described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively (or in addition), processor <NUM> may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit). Alternatively (or in addition) the processor <NUM>, in conjunction with one or more of the other components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> may be configured to implement part or all of the features described herein.

In some implementations, fifth generation (<NUM>) wireless communication will initially be deployed concurrently with current wireless communication standards (e.g., LTE). For example, dual connectivity between LTE and <NUM> new radio (<NUM> NR or NR) has been specified as part of the initial deployment of NR. Thus, as illustrated in <FIG>, evolved packet core (EPC) network <NUM> may continue to communicate with current LTE base stations (e.g., eNB <NUM>). In addition, eNB <NUM> may be in communication with a <NUM> NR base station (e.g., gNB <NUM>) and may pass data between the EPC network <NUM> and gNB <NUM>. Thus, EPC network <NUM> may be used (or reused) and gNB <NUM> may serve as extra capacity for UEs, e.g., for providing increased downlink throughput to UEs. In other words, LTE may be used for control plane signaling and NR may be used for user plane signaling. Thus, LTE may be used to establish connections to the network and NR may be used for data services.

<FIG> illustrates a proposed protocol stack for eNB <NUM> and gNB <NUM>. As shown, eNB <NUM> may include a medium access control (MAC) layer <NUM> that interfaces with radio link control (RLC) layers 622a-b. RLC layer 622a may also interface with packet data convergence protocol (PDCP) layer 612a and RLC layer 622b may interface with PDCP layer 612b. Similar to dual connectivity as specified in LTE-Advanced Release <NUM>, PDCP layer 612a may interface via a master cell group (MCG) bearer with EPC network <NUM> whereas PDCP layer 612b may interface via a split bearer with EPC network <NUM>.

Additionally, as shown, gNB <NUM> may include a MAC layer <NUM> that interfaces with RLC layers 624a-b. RLC layer 624a may interface with PDCP layer 612b of eNB <NUM> via an X<NUM> interface for information exchange and/or coordination (e.g., scheduling of a UE) between eNB <NUM> and gNB <NUM>. In addition, RLC layer 624b may interface with PDCP layer <NUM>. Similar to dual connectivity as specified in LTE-Advanced Release <NUM>, PDCP layer <NUM> may interface with EPC network <NUM> via a secondary cell group (SCG) bearer. Thus, eNB <NUM> may be considered a master node (MeNB) while gNB <NUM> may be considered a secondary node (SgNB). In some scenarios, a UE may operate to maintain a connection to both an MeNB and a SgNB. In such scenarios, the MeNB may be used to maintain a radio resource control (RRC) connection to an EPC while the SgNB may be used for capacity (e.g., additional downlink and/or uplink throughput).

Network slicing techniques are currently actively under development and may figure prominently in fifth generation ("<NUM>") cellular communication technologies. Network slicing is a concept introduced in <NUM> that may enable a cellular network operator to create customized networks to provide solutions for different market scenarios that have diverse requirements, e.g., in the areas of functionality, performance and isolation. For example, a cellular network may provide multiple network slices, where each network slice may include a set of network functions (NFs) selected to provide some specific telecommunication service(s) and network capabilities, and the resources to run these NFs. For example, global and regional organizations such as next generation mobile networks (NGMN), third generation partnership project (3GPP), <NUM> public private partnership (5GPPP), <NUM> Americas, <NUM> Forum, International Mobile Telecommunications <NUM> (IMT-<NUM>), etc., have documented possible use cases and requirements regarding network slicing.

Among the possible network slicing solutions, Radio Access Network (RAN) slicing and Core Network (CN) slicing are both possible and are currently under study by 3GPP RAN working groups (WGs) and 3GPP service and system aspects (SA) WGs separately. Network slicing is currently specified in 3GPP TS <NUM> sec <NUM> and 3GPP TS <NUM> sec <NUM>. When employing network slicing, the operator can deploy network slices that differ for supported features, or provide exactly the same features, but for different groups of UEs.

The following discussion applies generally to any wireless communication system employing a first cellular network that does not support network slicing, and a second cellular network that does support network slicing. For the sake of convenience, the discussion below refers to the first cellular network that does not support network slicing as a <NUM> Network and refers to the second cellular network that does support network slicing as a <NUM> Network. However, the methods described below may be used in any types or any of various generations of networks.

<FIG> illustrates an example system where a UE is in communication with a cellular network system that implements network slicing (e.g., a <NUM> Network). As shown, the UE communicates in a wireless manner to a cellular base station. The base station is in turn coupled to the cellular network. As shown, the cellular network may comprise a core access and mobility management function (AMF). The AMF may be coupled to different session management functions (SMF) and user plane functions. As shown, session management function <NUM> (SMF1) and user plane function <NUM> (UPF1) may form a first slice (Slice <NUM>) and may have a corresponding first S-NSSAI (single network slice selection assistance information), also referred to as a "Slice ID". In this example, Slice <NUM> is specified to perform video streaming. Session management function <NUM> (SMF2) and user plane function <NUM> (UPF2) may form a second slice (Slice <NUM>) and may have a corresponding second S-NSSAI. In this example, Slice <NUM> is specified to perform ultra-reliable low-latency communication (URLLC).

As shown in <FIG>, a single UE can be served by more than one Network Slice simultaneously (e.g., Slice <NUM> and Slice <NUM> in <FIG>). In this example, the AMF serving the UE in this case is common to all Network Slices. <FIG> also illustrates that multiple PDU sessions can share the same slice.

As shown in <FIG>, a network slice may be identified by an S-NSSAI, which is comprised of a slice/service type (SST) and a slice differentiator (SD). Inclusion of an SD in an S-NSSAI is optional. A set of one or more S-NSSAIs is called the NSSAI.

Network Slicing and UE Route Selection Policy (URSP) are not supported in <NUM> networks. However, during PDN connection establishment in a <NUM> network, the network may assign an S-NSSAI associated with the <NUM> PDN connection. The assignment of the S-NSSAI may be based on a combination of session management function (SMF), the packet data network gateway control plane function (PGW-C) address and Access Point Name (APN). The Access Point Name (APN) is essentially a type of gateway or anchoring point to which the UE is attached to gain access to the core network for at least a portion of its data service. The network may then send the assigned S-NSSAI to the UE in an information element (IE). For example, the assigned S-NSSAI may be sent in the Protocol Configuration Options (PCO) information element (IE) or Extended PCO IE in the Activate Default EPS Bearer Context Request message.

This S-NSSAI is not currently used when the UE is operating in a <NUM> network. However, when the UE moves from a <NUM> network to a <NUM> network, the UE may include the one or more S-NSSAIs received from the <NUM> network as the requested NSSAI in its Registration Request message. The UE may also set the S-NSSAI of the corresponding PDU session to the value previously received in the PCO IE as mentioned above. If the SMF+PGW-C supports more than one S-NSSAI and the APN is valid for more than one S-NSSAI, the SMF+PGW-C should only select an S-NSSAI that is mapped to the subscribed S-NSSAIs of the UE.

A problem can arise where the S-NSSAI(s) provided by the network internal logic may not be adequate for the network to correctly select the appropriate S-NSSAI for use by the UE after the UE transitions to a <NUM> network. In this case, the network may not select the correct S-NSSAI for use by the UE. As a consequence, after the UE Inter Rat (IRAT) transfer from a <NUM> network to a <NUM> network, if the PDU session of the <NUM> network is not linked to the correct S-NSSAI (e.g., if the PDU session is linked to the default slice instead of to the dedicated slice), the PDU session will be negatively impacted by this incorrect link. This negative impact will persist until the release of the PDU session. This may degrade (or negatively impact) the end user experience.

Currently the network may use the APN to determine the S-NSSAI to be used when the UE transitions from a <NUM> network to a <NUM> network. However, use of the APN may not be sufficient to allow the network to properly determine the correct S-NSSAI. Therefore, improvements in the field are desired.

In some embodiments, while camped on a <NUM> network, the UE may be configured to provide the <NUM> network with slice related information, thereby assisting the <NUM> network in providing the correct slice ID information to the UE while camped on the <NUM> network. More specifically, with this improved slice related information from the UE, the <NUM> network may then be able to include the correct S-NSSAI in in the Protocol configuration options IE or Extended protocol configuration options IE in the ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST message that is sent to the UE. In other words, this may enable the <NUM> network to provide the UE with the correct slice ID information (the correct S-NSSAIs) while camping on the <NUM> network.

Thus, when the UE transitions from the <NUM> network to a <NUM> network, this may enable the UE and the network to be able to link the <NUM> PDU sessions to the appropriate (or "correct") slices. Here it is noted that the PDU session may be linked to the correct slice in both the UE and the <NUM> Network without any signaling between the UE and the <NUM> Network. Instead, both the UE and the <NUM> Network depend on and utilize the S-NSSAI previously agreed upon while the UE was camping on the <NUM> Network. This enables the <NUM> network to link the <NUM> PDU session to the correct S-NSSAI, thereby providing an improved user experience on the <NUM> network. The terms "appropriate slice" or "correct slice" refers to a slice that most appropriately serves the type of application that is currently executing on the UE and is the subject of the current <NUM> PDU session.

Therefore, embodiments may relate to a UE that is configured to provide the <NUM> network with more slice related information to help the <NUM> network to include the right S-NSSAI in in the Protocol configuration options IE or Extended protocol configuration options IE in the ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST message. The UE may be configured to provide various types of slice related information (information related to the S-NSSAI) to the base station while camped on a <NUM> network.

<FIG> illustrates one embodiment of a method for a UE to provide improved slice related information to a <NUM> network, thereby allowing the <NUM> network to then provide the correct slice ID information (the correct S-NSSAI) back to the UE. As described above, this correct S-NSSAI may be used later after transition to a <NUM> network for improved operation.

As shown, at <NUM> the UE is camped on a <NUM> network and begins executing an application. Example applications include those that receive and present streaming video, perform various communication functions, etc. The UE may then establish a PDP (Packet Data Protocol) context. The PDP context is defined between the UE and the GGSN (Gateway GPRS Support Node) and defines information used for the connection.

At <NUM>, the UE determines if a URSP (UE Route Selection Policy) is available and whether the URSP contains a non-default rule (a rule other than the default rule) for the PDP to be established. If so, then operation proceeds to <NUM> where the UE follows the URSP policy and includes the designated S-NSSAI (the S-NSSAI indicated by the non-default rule of the URSP) in the PCO IE in a PDN Connectivity Request message to the <NUM> network.

Therefore, in this embodiment, while camping on a <NUM> network, if the UE has a URSP (UE Route Selection Policy), which may have been stored from previous camping on a <NUM> network, the UE follows the URSP to determine the S-NSSAI corresponding to the PDP context to be established. If the URSP contains a non-default rule for the PDP context to be established (a rule other than the default rule) as determined in <NUM>, then the UE may include the S-NSSAI specified by the URSP in the Protocol configuration options IE or Extended protocol configuration options IE in the PDN Connectivity Request message in <NUM>. This operates to provide the correct slice ID information to the <NUM> network. In this manner, the UE will later receive the "correct" S-NSSAI from the <NUM> network, as discussed below with respect to <FIG>.

While camping on <NUM>, if the UE has no URSP or if the UE has a URSP but there is no rule other than default rule (i.e., there is only the default rule) in the stored URSP for the PDP context to be established as determined in <NUM>, then operation proceeds to <NUM>.

In <NUM> the UE determines if the PDP context to be established belongs to a service related to a slice provided by a specific NSC (Network Slice Customer). The term "Network Slice Customer" refers to a Communication Service Provider (CSP) or Communication Service Customer (CSC) who uses a network slice as a service. If so, then in <NUM> the UE includes the NSC-ID in the Protocol Configuration Options (PCO) information element (IE) in the PDN Connectivity Request message sent by the UE to the <NUM> network. This operates to provide improved slice ID information to the <NUM> network. In this manner, the UE will later receive the "correct" S-NSSAI from the <NUM> network, as discussed below with respect to <FIG>. Alternatively, or in addition, in <NUM> the UE may include any of various types of slice related information which can be used by the <NUM> Network to provide the correct S-NSSAI.

Therefore, in the case specified by steps <NUM> and <NUM>, the UE may include additional information in the Protocol configuration options IE or Extended protocol configuration options IE in the PDN Connectivity Request message to help the network to determine the correct S-NSSAI. For example, in the case when the network slice is provided as a service, the UE may include the ID of the NSC who provided the slice. In other words, when the PDP context to be established belongs to a service related to a slice provided by a specific NSC, in this case the UE may inform the network about the NSC-ID in the Protocol configuration options IE or Extended protocol configuration options IE in the PDN Connectivity Request message. The <NUM> network can then use this received NSC-ID to provide the correct S-NSSAI to the UE as discussed below.

<FIG> is a flowchart diagram illustrating operation of the <NUM> Network after the operations in <FIG> have been performed. In other words, the operation of <FIG> presumes that the UE has provided a PDN Connectivity Request message containing slice related information to the <NUM> Network as described above in steps <NUM> and/or <NUM>.

As shown, at <NUM> the <NUM> Network receives, from the UE, a PDN Connectivity Request containing slice related information. The slice related information may be contained in a Protocol Configuration Options (PCO) information element (IE). The PDN Connectivity Request received in <NUM> may be one of the PDN Connectivity Requests transmitted by the UE in either <NUM> or <NUM> of <FIG>. The slice related information contained in the PDN Connectivity Request may be a proposed S-NSSAI as described above in <NUM> or may be an NSC-ID as described above in <NUM>.

In <NUM> the <NUM> Network determines the correct S-NSSAI at least in part based on the slice related information contained in the PDN Connectivity Request message and/or <NUM> Core Network internal logic. For example, where the slice related information is a proposed S-NSSAI (per <NUM> of <FIG>), the <NUM> Network may use this proposed S-NSSAI as the correct S-NSSAI. Alternatively, the <NUM> Network (the Core Network internal logic of the <NUM> Network) may determine that the proposed S-NSSAI sent by the UE in <NUM> is not correct, e.g., is stale or old. Here the <NUM> Network may have a more updated S-NSSAI that it believes should be used. As another example, where the slice related information is an NSC-ID in <NUM>, the <NUM> Network may determine the correct S-NSSAI based at least in part on this NSC-ID.

In <NUM> the <NUM> Network may transmit an Activate Default EPS Bearer Context Request message containing the correct S-NSSAI (as determined in <NUM>) to the UE. Thus, the UE provision of slice related information in one or more of <NUM> and <NUM> of <FIG> may be used by the <NUM> Network to assist in the <NUM> Network determining and providing the correct (or a more correct) slice ID (S_NSSAI) to the UE.

<FIG> is a flow diagram which illustrates operation of <FIG> and <FIG> at a higher level.

As shown, at <NUM> the UE transmits a PDN Connectivity Request to the <NUM> Network. This PDN Connectivity Request may include slice related information, such as a proposed S-NSSAI as described in <NUM> of <FIG>, or an NSC-ID as described in <NUM> of <FIG>.

In response to the PDN Connectivity Request received by the <NUM> Network in <NUM> (e.g., in <NUM> or <NUM>), at <NUM> the <NUM> Network may provide an Activate Default EPS Bearer Context Request message to the UE containing the correct NSSAI. Here <NUM> may encompass the operations performed in <NUM> and <NUM> of <FIG>. The UE receives and stores the correct Slice ID (the correct NSSAI) in <NUM>. In <NUM> the UE transmits an Activate Default EPS Bearer Context Accept () message back to the <NUM> Network accepting the message received in <NUM>.

In <NUM> the UE transmits an Activate Default EPS Bearer Context Accept message back to the <NUM> Network to complete the operation.

<FIG> illustrates an alternate non-claimed embodiment of a method whereby, instead of the UE providing slice related information to the <NUM> Network, the <NUM> Network may provide a list of (or a data structure containing) a subset or all of the valid Slice ID choices (valid S-NSSAIs) to the UE for consideration.

As sown, at <NUM> the UE provides a PDN Connectivity Request that is received by the <NUM> Network. In contrast to <NUM> of <FIG>, the PDN Connectivity Request does not include a proposed S-NSSAI.

At <NUM> the <NUM> Network transmits an Activate Default EPS Bearer Context Request message to the UE. This Activate Default EPS Bearer Context Request message may include a list of possible S-NSSAIs (a list of possible or valid Slice IDs). The UE receives this Activate Default EPS Bearer Context Request message, including the list of possible Slice IDs (the list of possible and/or valid S-NSSAIs) in <NUM>.

In <NUM> the UE selects the most appropriate (or "correct") S-NSSAI from the list of possible S-NSSAIs received in <NUM>. In <NUM> the UE then transmits the selected (the correct) S-NSSAI to the <NUM> Network in an Activate Default EPS Bearer Context Accept message. The correct S-NSSAI may be included in the PCO field of the Activate Default EPS Bearer Context Accept message.

Thus, in the embodiment of <FIG> when the UE initiates the PDN connectivity procedure, where multiple S-NSSAIs can be selected (to be linked to the corresponding PDU session) and the <NUM> Network does not have sufficient information to select the correct S-NSSAI, the <NUM> Network may provide or offer a subset or all of the valid S-NSSAI choices to the UE (<NUM>). The UE may then select the correct S-NSSAI from this list of S-NSSAIs provided by the <NUM> Network. The UE may either return the selected S-NSSAI to the <NUM> Core Network, specifically to the SMF+PGW-C logic in the <NUM> Network via PCO (as shown in <NUM> of <FIG>).

In some embodiments, when the UE moves from the <NUM> Network to the <NUM> Network, the UE may include the S-NSSAI received in the <NUM> Network in the configured NSSAI list which the UE used to create the requested NSSAI to inform the <NUM> Network regarding the network slices which the UE desires to later use.

<FIG> illustrates operation when the UE transitions from the <NUM> network to a <NUM> network (from a first cellular network to a second cellular network).

As shown, at <NUM> the UE begins an Inter RAT (Radio Access Technology) transfer from the <NUM> Network to the <NUM> Network. At <NUM> the <NUM> Network and the UE link the PDU session being established to the correct S-NSSAI(s) that was agreed upon while the UE was camping on the <NUM> Network. Here it is noted that the <NUM> Network has access to information contained in the <NUM> Network, and the <NUM> Network can use this access to determine the correct S-NSSAI(s) that was previously provided by the UE to the <NUM> Network, or which was determined by the <NUM> Network based at least in part on information that was provided to the <NUM> Network by the UE (e.g., in <NUM> or <NUM>).

Once the correct S-NSSAI(s) is determined by the <NUM> Network and the UE, as noted above both the UE and the <NUM> Network link the correct S-NSSAI(s) to the current PDU session between the UE and the <NUM> Network. This allows the correct network slice(s) in the <NUM> Network to be used in servicing the particular application needs of the UE, thus providing an improved user experience relative to prior art operation.

In some embodiments, a device (e.g., a UE <NUM>) may be configured to include a processor (or a set of processors) and a memory medium, where the memory medium stores program instructions, where the processor is configured to read and execute the program instructions from the memory medium, where the program instructions are executable to implement any of the various method embodiments described herein (or, any combination of the method embodiments described herein, or, any subset of any of the method embodiments described herein, or, any combination of such subsets). The device may be realized in any of various forms.

A wireless device (e.g., a UE <NUM>) may comprise wireless communication circuitry and at least one processor coupled to the wireless communication circuitry. Additionally, the at least one processor may be configured to cause the wireless device to transmit a packet data network (PDN) connectivity request to a first cellular network, wherein the first cellular network does not support network slicing. Additionally or alternatively, the at least one processor may be configured to cause the wireless device to receive a message from the first cellular network, wherein the message may comprise a list of a plurality of possible single network slice selection assistance information sets (S-NSSAIs). The at least one processor may be configured to cause the wireless device to select a desired S-NSSAI from the list of the plurality of possible S-NSSAIs, wherein the selected S-NSSAI may be useable when the wireless device transitions from the first cellular network to a second cellular network, and wherein the second cellular network may support network slicing.

Additionally or alternatively, the message received from the first cellular network comprising the list of the plurality of possible S-NSSAIs may be an Activate Default EPS Bearer Context Request message, according to some embodiments. The at least one processor may be further configured to cause the wireless device to transmit the selected S-NSSAI to the first cellular network. Additionally or alternatively, the at least one processor may be further configured to cause the wireless device to transmit the selected S-NSSAI to the first cellular network in an Activate Default EPS Bearer Context Accept message.

The at least one processor may be further configured to cause the wireless device to transition from the first cellular network to the second cellular network, wherein the transition comprises creation of a packet data unit (PDU) session between the UE and the second cellular network. Additionally or alternatively, the at least one processor may be further configured to cause the wireless device to link the S-NSSAI received from the first cellular network with the PDU session between the UE and the second cellular network. The first cellular network may be a <NUM> network and the second cellular network may be a <NUM> network.

Claim 1:
A method, comprising:
by a user equipment, UE (<NUM>):
initiating an application on the UE (<NUM>), while
connected with a first cellular network (<NUM>), wherein the first cellular network (<NUM>) does not support network slicing;
determining slice related information for the application;
determining if a UE route selection policy, URSP, contains a non-default rule for a packet data protocol, PDP, context between the UE (<NUM>) and the first cellular network (<NUM>), wherein:
when the URSP contains a non-default rule for the PDP context between the UE (<NUM>) and the first cellular network (<NUM>), the method further comprises determining, according to the non-default rule of the URSP, a proposed single network slice selection assistance information, S-NSSAI, wherein the slice related information is the proposed S-NSSAI;
when the URSP does not contain a non-default rule for the PDP context between the UE (<NUM>) and the first cellular network (<NUM>), and when the PDP context is associated with a service related to a slice provided by a specific network slice customer, NSC, the method further comprises determining an identifier of the NSC, wherein the slice related information is the identifier of the NSC;
providing the slice related information to the first cellular network (<NUM>); and
receiving a S-NSSAI from the first cellular network, wherein the S-NSSAI was determined based at least in part on the slice related information provided by the UE (<NUM>) to the first cellular network (<NUM>);
wherein the S-NSSAI is useable when the UE (<NUM>) transitions to a second cellular network that does support network slicing.