After switching to different subscriptions for dual-subscriber identity modules and dual-standby user devices, packet data sessions are dismantled.

Abstract

Technology for wireless communication is disclosed. In one aspect, a Subscriber Identity Module (SIM) Dual Standby (DSDS) User Equipment (UE) can switch a packet data session from a first Radio Access Technology (RAT) associated with a first subscription to a second RAT associated with a second subscription, and can further transmit one or more messages via the first RAT to terminate the packet data session via the first RAT in response to the switch of the packet data session to the second RAT.

Description

[0001] Public background

[0002] 1. Public domain

[0003] The various aspects of this disclosure generally relate to wireless communications.

[0004] 2. Relevant Technical Descriptions

[0005] Wireless communication systems have undergone several generations of development, including first-generation analog radiotelephone service (1G), second-generation (2G) digital radiotelephone service (including transitional 2.5G and 2.75G networks), third-generation (3G) high-speed data radio service with Internet capabilities, and fourth-generation (4G) service (e.g., Long Term Evolution (LTE) or WiMax). Currently, many different types of wireless communication systems are in use, including cellular and Personal Communication Services (PCS) systems. Known examples of cellular systems include cellular analog Advanced Mobile Phone Systems (AMPS), and digital cellular systems based on Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Global System for Mobile Communications (GSM), etc.

[0006] The fifth-generation (5G) wireless standard (known as New Radio (NR)) demands higher data transmission speeds, a greater number of connections, better coverage, and other improvements. According to the Next Generation Mobile Networks Alliance (NGC), the 5G standard is designed to provide tens of megabits per second (Mbps) of data rate to each of tens of thousands of users, and 1 gigabits per second (Gbps) to dozens of employees on an office floor. It should support hundreds of thousands of simultaneous connections to support large-scale sensor deployments. Therefore, 5G mobile communication should have significantly improved spectral efficiency compared to the current 4G standard. Furthermore, signaling efficiency should be improved and latency significantly reduced compared to the current standard.

[0007] Overview

[0008] In some aspects, a wireless communication method performed by a dual subscriber identity module (SIM) dual standby (DSDS) user equipment (UE) includes: switching a packet data session from a first radio access technology (RAT) associated with a first subscription to a second RAT associated with a second subscription; and transmitting one or more messages via the first RAT to terminate the packet data session via the first RAT in response to the switch of the packet data session to the second RAT.

[0009] In some respects, the first subscription is the default data subscription (DDS) subscription, and the second subscription is a non-DDS subscription.

[0010] In some respects, the first subscription is a non-default data subscription (DDS) subscription, and the second subscription is a DDS subscription.

[0011] In some respects, the first RAT and the second RAT are different.

[0012] In some respects, the first RAT is 4G Long Term Evolution (LTE), and the second RAT is 5G New Radio (NR).

[0013] In some respects, the first RAT and the second RAT are the same.

[0014] In some respects, the first RAT and the second RAT are 4G Long Term Evolution (LTE).

[0015] In some respects, the first RAT and the second RAT are 5G New Radio (NR).

[0016] In some aspects, the method includes receiving downlink packet data via a first RAT after a packet data session transitions to a second RAT, wherein the transmission of the one or more messages is triggered in response to the received downlink packet data.

[0017] In some respects, the transmission of one or more messages is directly triggered based on the transition of the packet data session to the second RAT.

[0018] In some respects, the first RAT is 4G Long Term Evolution (LTE).

[0019] In some respects, the message may include a packet data network (PDN) disconnection request.

[0020] In some respects, the one or more messages further include a PDC connectivity request message following the PDN disconnection request.

[0021] In some respects, the message includes a Tracking Area Update (TAU) with an Evolved Packet System (EPS) identifier (ID) that is set to false.

[0022] In some respects, the first RAT is 5G New Radio (NR).

[0023] In some respects, the message may include a Packet Data Unit (PDU) session release request, a PDU session release completion request, and a PDU session establishment request.

[0024] In some aspects, a dual subscriber identity module (SIM) dual standby (DSDS) user equipment (UE) includes: a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: switch a packet data session from a first radio access technology (RAT) associated with a first subscription to a second RAT associated with a second subscription; and, in response to the switch of the packet data session to the second RAT, transmit one or more messages via the first RAT to terminate the packet data session via the first RAT.

[0025] In some respects, the first subscription is the default data subscription (DDS) subscription, and the second subscription is a non-DDS subscription.

[0026] In some respects, the first RAT and the second RAT are different.

[0027] In some respects, the first RAT and the second RAT are the same.

[0028] In some aspects, the at least one processor is further configured to receive downlink packet data via the first RAT after the packet data session transitions to the second RAT, wherein the transmission of the one or more messages is triggered in response to the received downlink packet data.

[0029] In some respects, the transmission of one or more messages is directly triggered based on the transition of the packet data session to the second RAT.

[0030] In some aspects, a Subscriber Identity Module (SIM) Dual Standby (DSDS) User Equipment (UE) includes: means for switching a packet data session from a first radio access technology (RAT) associated with a first subscription to a second RAT associated with a second subscription; and means for transmitting one or more messages via the first RAT to terminate the packet data session via the first RAT in response to the switching of the packet data session to the second RAT.

[0031] In some respects, the first subscription is the default data subscription (DDS) subscription, and the second subscription is a non-DDS subscription.

[0032] In some respects, the first RAT and the second RAT are different.

[0033] In some respects, the first RAT and the second RAT are the same.

[0034] In some aspects, the method includes: means for receiving downlink packet data via a first RAT after a packet data session transitions to a second RAT, wherein the transmission of the one or more messages is triggered in response to the received downlink packet data.

[0035] In some respects, the transmission of one or more messages is directly triggered based on the transition of the packet data session to the second RAT.

[0036] In some aspects, a non-transient computer-readable medium storing a set of instructions, the set of instructions comprising one or more instructions, which, when executed by one or more processors of a dual subscriber identity module (SIM) dual standby (DSDS) user equipment (UE), cause the DSDS UE to: switch a packet data session from a first radio access technology (RAT) associated with a first subscription to a second RAT associated with a second subscription; and, in response to the switch of the packet data session to the second RAT, transmit one or more messages via the first RAT to terminate the packet data session via the first RAT.

[0037] In some respects, the first subscription is the default data subscription (DDS) subscription, and the second subscription is a non-DDS subscription.

[0038] The following is a simplified overview relating to one or more aspects disclosed herein. Therefore, this overview should not be considered an exhaustive overview relating to all aspects of the conception, nor should it be considered to identify key or decisive elements relating to all aspects of the conception or to depict the scope associated with any particular aspect. Accordingly, the sole purpose of the following overview is to present, in a simplified form, certain concepts relating to one or more aspects of the mechanism disclosed herein before the detailed description given below.

[0039] Other objectives and advantages associated with the aspects disclosed herein will be apparent to those skilled in the art based on the accompanying drawings and detailed description. Brief description of the attached diagram

[0041] The accompanying drawings are provided to help describe various aspects of this disclosure, and the drawings are provided for illustrative purposes only and not for limiting the aspects.

[0042] Figure 1 Example wireless communication systems based on various aspects of this disclosure are explained.

[0043] Figure 2A and 2B Example wireless network architectures based on various aspects of this disclosure are explained.

[0044] Figures 3A to 3CIt is a simplified block diagram of several examples of components that can be used in user equipment (UE), base stations, and network entities and configured to support communications as taught herein.

[0045] Figure 4 The various Radio Resource Control (RRC) states available in the New Radio (NR) according to various aspects of this disclosure are explained.

[0046] Figure 5 The DDS transformation procedure according to one aspect of this disclosure is explained.

[0047] Figure 6 An exemplary process of wireless communication according to one aspect of this disclosure is explained.

[0048] Figure 7-12 Each explained one aspect of this disclosure. Figure 6 Example implementation of the process.

[0049] Detailed description

[0050] Various aspects of this disclosure are provided below in the description and accompanying drawings of various examples provided for illustrative purposes. Alternative aspects may be designed without departing from the scope of this disclosure. Furthermore, elements well-known in this disclosure will not be described in detail or will be omitted so as not to obscure the relevant details of this disclosure.

[0051] The terms “exemplary” and / or “example” are used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” and / or “example” is not necessarily to be construed as superior to or better than the others. Similarly, the term “aspects of this disclosure” does not require that all aspects of this disclosure include the features, advantages, or modes of operation discussed.

[0052] Those skilled in the art will appreciate that the information and signals described below can be represented using any of a variety of different techniques and arts. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the following description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof, depending in part on the specific application, in part on the desired design, in part on the corresponding technology, etc.

[0053] Furthermore, many aspects are described in the form of sequences of actions performed by elements of, for example, computing devices. It will be appreciated that the various actions described herein can be performed by special-purpose circuitry (e.g., application-specific integrated circuits (ASICs)), by program instructions being executed by one or more processors, or by a combination of both. Additionally, the sequences of actions described herein can be considered to be fully embodied in any form of non-transient computer-readable storage medium storing a corresponding set of computer instructions that, upon execution, will cause an associated processor of the device to perform the functions described herein. Thus, various aspects of this disclosure can be embodied in several different forms, all of which are contemplated to fall within the scope of the claimed subject matter. Furthermore, for each aspect described herein, a corresponding form of any such aspect may be described herein as, for example, "logic configured to perform the described actions."

[0054] As used herein, the terms “User Equipment” (UE) and “Base Station” are not intended to be specific to or otherwise limited to any particular Radio Access Technology (RAT) unless otherwise stated. Generally, a UE can be any wireless communication device used by a user to communicate over a wireless communication network (e.g., mobile phone, router, tablet computer, laptop computer, consumer asset tracking device, wearable device (e.g., smartwatch, glasses, augmented reality (AR) / virtual reality (VR) headset, etc.), vehicle (e.g., car, motorcycle, bicycle, etc.), Internet of Things (IoT) device, etc.). A UE can be mobile or can (e.g., at certain times) be stationary and can communicate with a Radio Access Network (RAN). As used herein, the term “UE” can be interchangeably referred to as “Access Terminal” or “AT”, “Client Equipment”, “Wireless Equipment”, “Subscriber Equipment”, “Subscriber Terminal”, “Subscriber Station”, “User Terminal” or “UT”, “Mobile Equipment”, “Mobile Terminal”, “Mobile Station”, or variations thereof. Generally, a UE can communicate with the core network via the RAN, and through the core network, the UE can connect to external networks (such as the Internet) and other UEs. Of course, other mechanisms for connecting to the core network and / or the Internet are also possible for the UE, such as through a wired access network, a wireless local area network (WLAN) (e.g., based on the IEEE 802.11 standard), and so on.

[0055] A base station may operate according to one of several RATs to communicate with a UE, depending on the network in which it is deployed, and may be alternatively referred to as an Access Point (AP), Network Node, B-Node, Evolved B-Node (eNB), Next Generation eNB (ng-eNB), New Radio (NR) B-Node (also referred to as gNB or gNodeB), etc. A base station may primarily be used to support radio access by the UE, including supporting data, voice, and / or signaling connections with the supported UE. In some systems, the base station may provide purely edge node signaling functions, while in others, it may provide additional control and / or network management functions. The communication link through which the UE can signal to the base station is called an uplink (UL) channel (e.g., reverse traffic channel, reverse control channel, access channel, etc.). The communication link through which the base station can signal to the UE is called a downlink (DL) or forward link channel (e.g., paging channel, control channel, broadcast channel, forward traffic channel, etc.). As used herein, the term traffic channel (TCH) may refer to an uplink / reverse traffic channel or a downlink / forward traffic channel.

[0056] The term "base station" can refer to a single physical transmit / receive point (TRP) or multiple physical TRPs that may or may not be located in the same place. For example, when the term "base station" refers to a single physical TRP, the physical TRP may be a base station antenna corresponding to a cell (or several cell sectors) of the base station. When the term "base station" refers to multiple physical TRPs located in the same place, the physical TRP may be an antenna array of the base station (e.g., in a multiple-input multiple-output (MIMO) system or in the case of beamforming at the base station). When the term "base station" refers to multiple physical TRPs not located in the same place, the physical TRP may be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via a transmission medium) or a remote radio headend (RRH) (a remote base station connected to a serving base station). Alternatively, non-co-located physical TRPs may be the serving base station from which the UE receives measurement reports and a neighboring base station from which the UE is measuring its reference RF signal. Since a TRP is the point from which a base station transmits and receives wireless signals, as used herein, references to transmissions from or receptions at a base station should be understood as references to the specific TRP of that base station.

[0057] In some implementations that support UE positioning, the base station may not support the UE's radio access (e.g., it may not support data, voice, and / or signaling connections regarding the UE), but may instead transmit reference signals to the UE for measurement, and / or receive and measure signals transmitted by the UE. Such a base station may be referred to as a positioning tower (e.g., in the case of transmitting signals to the UE) and / or as a location measurement unit (e.g., in the case of receiving and measuring signals from the UE).

[0058] An “RF signal” refers to an electromagnetic wave of a given frequency that transmits information across the space between a transmitter and a receiver. As used herein, a transmitter may transmit a single “RF signal” or multiple “RF signals” to a receiver. However, due to the propagation characteristics of individual RF signals through a multipath channel, a receiver may receive multiple “RF signals” corresponding to each transmitted RF signal. The same RF signal transmitted on different paths between the transmitter and receiver can be referred to as a “multipath” RF signal.

[0059] Figure 1 An example wireless communication system 100 has been described. The wireless communication system 100 (also referred to as a wireless wide area network (WWAN)) may include individual base stations 102 and individual UEs 104. Base station 102 may include macrocell base stations (high-power cellular base stations) and / or small cell base stations (low-power cellular base stations). In one aspect, macrocell base stations may include eNBs and / or ng-eNBs (where wireless communication system 100 corresponds to an LTE network), or gNBs (where wireless communication system 100 corresponds to an NR network), or a combination of both, and small cell base stations may include femtocells, picocells, microcells, etc.

[0060] Each base station 102 can collectively form a RAN and interface with a core network 170 (e.g., an evolved packet core (EPC) or a 5G core (5GC)) via a backhaul link 122, and connect to one or more location servers 172 (which may be part of the core network 170 or external to it) via the core network 170. Among other functions, base stations 102 can also perform functions related to one or more of the following: transmitting user data, radio channel cryptography and decoding, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment tracking, RAN information management (RIM), paging, location, and delivery of alarm messages. Base stations 102 can communicate with each other directly or indirectly (e.g., via EPC / 5GC) via a backhaul link 134 (which may be wired or wireless).

[0061] Base station 102 can wirelessly communicate with UE 104. Each base station 102 can provide communication coverage for its respective geographical coverage area 110. In one aspect, one or more cells can be supported by base station 102 in each geographical coverage area 110. A “cell” is a logical communication entity used to communicate with a base station (e.g., on a frequency resource, referred to as a carrier frequency, component carrier, carrier, frequency band, etc.) and can be associated with an identifier (e.g., Physical Cell Identifier (PCI), Virtual Cell Identifier (VCI), Cell Global Identifier (CGI)) to distinguish cells operating via the same or different carrier frequencies. In some cases, different cells can be configured according to different protocol types that can provide access to different types of UEs (e.g., Machine Type Communication (MTC), Narrowband IoT (NB-IoT), Enhanced Mobile Broadband (eMBB), or others). Since cells are supported by specific base stations, the term “cell” can refer to either or both of the logical communication entity and the base station supporting that logical communication entity, depending on the context. In some contexts, the term "cellular" can also refer to the geographical coverage area (e.g., sector) of a base station, in the sense that the carrier frequency can be detected and used for communication within a portion of the geographic coverage area 110.

[0062] While the geographic coverage areas 110 of adjacent macrocell base stations 102 may partially overlap (e.g., in handover areas), some geographic coverage areas 110 may substantially overlap with larger geographic coverage areas 110. For example, a small cell (SC) base station 102' may have geographic coverage areas 110' that substantially overlap with the geographic coverage areas 110 of one or more macrocell base stations 102. A network that includes both small cell and macrocell base stations may be referred to as a heterogeneous network. A heterogeneous network may also include home eNBs (HeNBs) that provide service to a restricted group known as a Closed Subscriber Group (CSG).

[0063] The communication link 120 between base station 102 and UE 104 may include uplink (also known as reverse link) transmission from UE 104 to base station 102 and / or downlink (also known as forward link) transmission from base station 102 to UE 104. The communication link 120 may use MIMO antenna technologies, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link 120 may use one or more carrier frequencies. Carrier allocation may be asymmetric with respect to the downlink and uplink (e.g., more or fewer carriers may be allocated to the downlink compared to the uplink).

[0064] The wireless communication system 100 may further include a wireless local area network (WLAN) access point (AP) 150 communicating with a WLAN station (STA) 152 via a communication link 154 in unlicensed spectrum (e.g., 5 GHz). When communicating in unlicensed spectrum, the WLAN STA 152 and / or WLAN AP 150 may perform a clear channel assessment (CCA) or listen-before-speak (LBT) procedure to determine channel availability before communication.

[0065] Small cell base station 102' can operate in licensed and / or unlicensed spectrum. When operating in unlicensed spectrum, small cell base station 102' can employ LTE or NR technology and use the same 5 GHz unlicensed spectrum as used by WLAN AP 150. Small cell base station 102' employing LTE / 5G in unlicensed spectrum can enhance access network coverage and / or increase access network capacity. NR in unlicensed spectrum may be referred to as NR-U. LTE in unlicensed spectrum may be referred to as LTE-U, Licensed Assisted Access (LAA), or MulteFire.

[0066] The wireless communication system 100 may further include a millimeter-wave (mmW) base station 180, which can operate in mmW and / or near-mmW frequencies to communicate with the UE 182. Extremely high frequency (EHF) is a portion of the electromagnetic spectrum that contains radio frequency (RF). EHF has a range of 30 GHz to 300 GHz and wavelengths between 1 mm and 10 mm. Radio waves in this band are referred to as millimeter waves. Near-mmW extends down to a 3 GHz frequency with a 100 mm wavelength. Ultra-high frequency (SHF) bands extend between 3 GHz and 30 GHz, and are also referred to as centimeter waves. Communication using mmW / near-mmW RF bands has high path loss and relatively short range. The mmW base station 180 and the UE 182 can utilize beamforming (transmit and / or receive) on the mmW communication link 184 to compensate for the extremely high path loss and short range. Furthermore, it will be appreciated that in alternative configurations, one or more base stations 102 may also use mmW or near-mmW and beamforming for transmission. Accordingly, it will be understood that the foregoing explanations are merely illustrative and should not be construed as limiting the aspects disclosed herein.

[0067] Transmit beamforming is a technique for focusing RF signals in a specific direction. Conventionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omnidirectionally). Using transmit beamforming, the network node determines where a given target device (e.g., a UE) is located (relative to the transmitting network node) and projects a stronger downlink RF signal in that specific direction, thus providing the receiving device with a faster (in terms of data rate) and stronger RF signal. To change the directivity of the RF signal during transmission, the network node can control the phase and relative amplitude of the RF signal at each of one or more transmitters broadcasting the RF signal. For example, the network node can use an antenna array (referred to as a "phased array" or "antenna array") that generates a beam of RF waves, which can be "guided" to different directions without actually moving the antennas. Specifically, RF currents from the transmitters are fed to the individual antennas with the correct phase relationship so that radio waves from the separate antennas add together in the desired direction to increase radiation, while simultaneously canceling each other out in the undesired direction to suppress radiation.

[0068] Transmit beams can be quasi-co-located, meaning they appear to the receiver (e.g., the UE) with identical parameters, regardless of whether the network node's transmit antennas are physically co-located. In NR, there are four types of quasi-co-location (QCL) relationships. Specifically, a given type of QCL relationship means that certain parameters of the target reference RF signal on the target beam can be derived from information about the source reference RF signal on the source beam. If the source reference RF signal is QCL type A, the receiver can use the source reference RF signal to estimate the Doppler shift, Doppler spread, average delay, and delay spread of the target reference RF signal transmitted on the same channel. If the source reference RF signal is QCL type B, the receiver can use the source reference RF signal to estimate the Doppler shift and Doppler spread of the target reference RF signal transmitted on the same channel. If the source reference RF signal is QCL type C, the receiver can use the source reference RF signal to estimate the Doppler shift and average delay of the target reference RF signal transmitted on the same channel. If the source reference RF signal is of type QCL D, the receiver can use the source reference RF signal to estimate the spatial reception parameters of the target reference RF signal transmitted on the same channel.

[0069] In receive beamforming, a receiver uses a receive beam to amplify an RF signal detected on a given channel. For example, a receiver may increase the gain setting of an antenna array and / or adjust the phase setting of the antenna array in a specific direction to amplify the RF signal received from that direction (e.g., increase its gain level). Thus, when a receiver is referred to as beamforming in a certain direction, it means that the beam gain in that direction is higher than the beam gain in other directions, or that the beam gain in that direction is the highest compared to the beam gain of all other receive beams available to the receiver in that direction. This results in a stronger received signal strength (e.g., Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Signal-to-Interference-plus-Noise Ratio (SINR), etc.) of the RF signal received from that direction.

[0070] The receive beam can be spatially dependent. Spatial dependency means that the parameters of the transmit beam used for the second reference signal can be derived from information about the receive beam of the first reference signal. For example, the UE can use a specific receive beam to receive one or more reference downlink reference signals (e.g., Position Reference Signal (PRS), Tracking Reference Signal (TRS), Phase Tracking Reference Signal (PTRS), Cell-Specific Reference Signal (CRS), Channel State Information Reference Signal (CSI-RS), Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), Synchronization Block (SSB), etc.) from the base station. The UE can then form a transmit beam based on the parameters of the receive beam to transmit one or more uplink reference signals (e.g., Uplink Position Reference Signal (UL-PRS), Detection Reference Signal (SRS), Demodulation Reference Signal (DMRS), PTRS, etc.) to the base station.

[0071] Note that, depending on the entity forming the "downlink" beam, the beam can be either a transmit beam or a receive beam. For example, if a base station is forming a downlink beam to transmit a reference signal to a UE, then the downlink beam is a transmit beam. However, if a UE is forming a downlink beam, then the downlink beam is a receive beam for receiving downlink reference signals. Similarly, depending on the entity forming the "uplink" beam, the beam can be either a transmit beam or a receive beam. For example, if a base station is forming an uplink beam, then the uplink beam is an uplink receive beam, while if a UE is forming an uplink beam, then the uplink beam is an uplink transmit beam.

[0072] In 5G, the spectrum in which radio nodes (e.g., base stations 102 / 180, UE 104 / 182) operate is divided into multiple frequency ranges: FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). In multi-carrier systems (such as 5G), one of the carrier frequencies is referred to as the “primary carrier” or “anchor carrier” or “primary serving cell” or “PCell,” and the remaining carrier frequencies are referred to as “secondary carriers” or “secondary serving cells” or “SCell.” In carrier aggregation, the anchor carrier is the carrier operating on the primary frequency (e.g., FR1) utilized by UE 104 / 182 and on the cell in which UE 104 / 182 performs an initial radio resource control (RRC) connection establishment procedure or initiates an RRC connection re-establishment procedure. The primary carrier carries all shared control channels as well as UE-specific control channels, and can be a carrier on a licensed frequency (however, this is not always the case). The secondary carrier is a carrier operating on a second frequency (e.g., FR2), which can be configured once an RRC connection is established between UE 104 and the anchor carrier, and can be used to provide additional radio resources. In some cases, the secondary carrier can be a carrier on an unlicensed frequency. The secondary carrier may contain only the necessary signaling information and signals; for example, UE-specific signaling information and signals may not be present on the secondary carrier, since both the primary uplink and downlink carriers are typically UE-specific. This means that different UEs 104 / 182 in a cell can have different downlink primary carriers. The same applies to the uplink primary carrier. The network can change the primary carrier of any UE 104 / 182 at any time. For example, this is done to balance the load on different carriers. Since a “serving cell” (whether PCell or SCell) corresponds to the carrier frequency / component carrier that a base station is using for communication, the terms “cell,” “serving cell,” “component carrier,” “carrier frequency,” etc., can be used interchangeably.

[0073] For example, still refer to Figure 1 One of the frequencies utilized by the macrocell base station 102 can be an anchor carrier (or "PCell"), and other frequencies utilized by the macrocell base station 102 and / or mmW base station 180 can be secondary carriers ("SCell"). Simultaneous transmission and / or reception on multiple carriers allows the UE 104 / 182 to significantly increase its data transmission and / or reception rates. For example, two 20MHz aggregated carriers in a multi-carrier system would theoretically result in twice the data rate (i.e., 40MHz) compared to the data rate obtained from a single 20MHz carrier.

[0074] The wireless communication system 100 may further include a UE 164, which can communicate with the macrocell base station 102 on the communication link 120 and / or with the mmW base station 180 on the mmW communication link 184. For example, the macrocell base station 102 may support PCell and one or more SCells for the UE 164, and the mmW base station 180 may support one or more SCells for the UE 164.

[0075] exist Figure 1 In the example, one or more Earth-orbiting Satellite Positioning System (SPS) spacecraft (SV) 112 (e.g., satellites) can be used as any of the explained UEs (for simplicity, in...). Figure 1 The location information of a single UE 104 is a separate source. UE 104 may include one or more dedicated SPS receivers specifically designed to receive signals from SV 112 via a corresponding satellite communication link 124 to derive geographic location information. The SPS typically includes a transmitter system (e.g., SV 112) positioned such that receivers (e.g., UE 104) can determine their location on or above the earth based at least in part on signals received from the transmitter. Such transmitters typically transmit signals marked with a set number of repeating pseudo-random noise (PN) codes. While transmitters are typically located in SV 112, they may sometimes be located at a terrestrial control station, base station 102, and / or other UE 104.

[0076] The use of SPS signals can be amplified through various satellite-based augmentation systems (SBAS), which may be associated with or otherwise enabled to work with one or more global and / or regional navigation satellite systems. For example, SBAS may include augmentation systems that provide integrity information, differential correction, etc., such as Wide Area Augmentation System (WAAS), European Geostationary Navigation Coverage Service (EGNOS), Multifunctional Satellite Augmentation System (MSAS), GPS-assisted Geographic Augmentation Navigation or GPS and Geographic Augmentation Navigation System (GAGAN), etc. Therefore, as used herein, SPS may include any combination of one or more global and / or regional navigation satellite systems and / or augmentation systems, and SPS signals may include SPS, SPS-like systems, and / or other signals associated with one or more such SPS.

[0077] The wireless communication system 100 may further include one or more UEs (such as UE 190) that are indirectly connected to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links (referred to as “side links”). Figure 1 In the example, UE 190 has a D2D P2P link 192 with a UE 104 connected to a base station 102 (e.g., through which UE 190 indirectly obtains cellular connectivity), and a D2D P2P link 194 with a WLANSTA 152 connected to a WLAN AP 150 (through which UE 190 indirectly obtains WLAN-based Internet connectivity). In one example, D2D P2P links 192 and 194 can use any known D2D RAT (such as LTE Direct (LTE-D), WiFi Direct (WiFi-D)). (etc.) to support.

[0078] Figure 2A Example wireless network architecture 200 is explained. For example, 5GC 210 (also referred to as Next Generation Core (NGC)) can be functionally considered as control plane functions 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and user plane functions 212 (e.g., UE gateway functions, access to data networks, IP routing, etc.), which operate collaboratively to form the core network. User plane interface (NG-U) 213 and control plane interface (NG-C) 215 connect gNB 222 to 5GC 210, specifically to control plane functions 214 and user plane functions 212. In an additional configuration, ng-eNB 224 can also connect to 5GC 210 via NG-C 215 to control plane function 214 and NG-U 213 to user plane function 212. Furthermore, ng-eNB 224 can communicate directly with gNB 222 via backhaul connection 223. In some configurations, the new RAN 220 may have only one or more gNB 222s, while other configurations include both one or more ng-eNB 224s and one or more gNB 222s. The gNB 222 or ng-eNB 224 can be used with UE 204 (e.g., Figure 1 The UE 204 can communicate with any UE depicted herein. Another optional aspect may include a location server 230, which may communicate with the 5GC 210 to provide location assistance to the UE 204. The location server 230 may be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules extending across multiple physical servers, etc.), or alternatively, each may correspond to a single server. The location server 230 may be configured to support one or more location services for the UE 204, which can connect to the location server 230 via the core network, the 5GC 210, and / or via the Internet (not described). Furthermore, the location server 230 may be integrated into a component of the core network, or alternatively, may be external to the core network.

[0079] Figure 2B Another example wireless network architecture 250 is described. For example, 5GC 260 can be functionally considered as a control plane function (provided by Access and Mobility Management Function (AMF) 264) and a user plane function (provided by User Plane Function (UPF) 262), which operate cooperatively to form the core network (i.e., 5GC 260). User plane interface 263 and control plane interface 265 connect ng-eNB 224 to 5GC 260, specifically to UPF 262 and AMF 264, respectively. In an additional configuration, gNB 222 can also connect to 5GC 260 via control plane interface 265 to AMF 264 and user plane interface 263 to UPF 262. Furthermore, ng-eNB 224 can communicate directly with gNB 222 via backhaul connection 223, with or without gNB direct connectivity to 5GC 260. In some configurations, the new RAN 220 may have only one or more gNB 222s, while other configurations include both one or more ng-eNB 224s and one or more gNB 222s. The gNB 222 or ng-eNB 224 can be used with UE 204 (e.g., Figure 1 The base station of the new RAN 220 communicates with the AMF 264 via the N2 interface and with the UPF 262 via the N3 interface.

[0080] The functions of AMF 264 include registration management, connection management, reachability management, mobility management, lawful interception, transmission of Session Management (SM) messages between UE 204 and Session Management Function (SMF) 266, transparent proxy service for routing SM messages, access authentication and access authorization, transmission of Short Message Service (SMS) messages between UE 204 and Short Message Service Function (SMSF) (not shown), and Security Anchor Functionality (SEAF). AMF 264 also interacts with Authentication Server Function (AUSF) (not shown) and UE 204, and receives an intermediate key established as a result of the UE 204 authentication process. In the case of authentication based on the UMTS (Universal Mobile Telecommunications System) Subscriber Identity Module (USIM), AMF 264 retrieves security material from the AUSSF. The functions of AMF 264 also include Security Context Management (SCM). The SCM receives a key from the SEAF, which is used by the SCM to derive a key that varies depending on the access network. The functionality of AMF 264 also includes: location service management for regulatory services, transmission of location service messages between UE 204 and Location Management Function (LMF) 270 (which acts as location server 230), transmission of location service messages between the new RAN 220 and LMF 270, allocation of EPS bearer identifiers for interoperability with Evolved Packet Systems (EPS), and UE 204 mobility event notification. Additionally, AMF 264 supports functionality in non-3GPP (3rd Generation Partnership Project) access networks.

[0081] The functions of UPF 262 include: acting as an anchor point for intra / inter-RAT mobility (where applicable), acting as an external Protocol Data Unit (PDU) session point interconnecting to a data network (not shown), providing packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., strobing, redirection, traffic steering), lawful interception (user plane collection), traffic usage reporting, quality of service (QoS) handling for user plane (e.g., uplink / downlink rate enforcement, reflective QoS marking in the downlink), uplink traffic verification (Service Data Flow (SDF) to QoS Flow mapping), transport-level packet marking in the uplink and downlink, downlink packet buffering and downlink data notification triggering, and sending and forwarding one or more "end markers" to the source RAN node. UPF 262 may also support the transmission of location service messages on the user plane between UE 204 and a location server (such as Secure User Plane Positioning (SUPL) Location Platform (SLP) 272).

[0082] The functions of SMF 266 include session management, UE Internet Protocol (IP) address allocation and management, selection and control of user plane functions, traffic bootstrapping configuration at UPF 262 for routing traffic to the correct destination, partial control of policy enforcement and QoS, and downlink data notification. The interface used by SMF 266 to communicate with AMF 264 is called the N11 interface.

[0083] Another optional aspect may include LMF 270, which can communicate with 5GC 260 to provide location assistance to UE 204. LMF 270 can be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules extending across multiple physical servers, etc.), or alternatively, each may correspond to a single server. LMF 270 can be configured to support one or more location services for UE 204, which can connect to LMF 270 via the core network, 5GC 260, and / or via the Internet (not explained). SLP 272 supports similar functionality to LMF 270, but while LMF 270 can communicate with AMF 264, the new RAN 220, and UE 204 on the control plane (e.g., using interfaces and protocols designed to convey signaling messages rather than voice or data), SLP 272 can communicate with UE 204 and external clients on the user plane (e.g., using protocols designed to carry voice and / or data, such as Transmission Control Protocol (TCP) and / or IP). Figure 2B (Not shown in the image) communicates.

[0084] Figure 3A , 3B The document describes several example components (represented by corresponding boxes) that can be incorporated into UE 302 (which may correspond to any UE described herein), base station 304 (which may correspond to any base station described herein), and network entity 306 (which may correspond to or embody any network function described herein, including location server 230 and LMF 270) to support file transfer operations as taught herein. It will be appreciated that these components can be implemented in different types of devices (e.g., in ASICs, in system-on-chips (SoCs), etc.) in different implementations. The described components can also be incorporated into other devices in a communication system. For example, other devices in the system may include components similar to those described to provide similar functionality. Furthermore, a given device may include one or more of these components. For example, a device may include multiple transceiver components that enable the device to operate on multiple carriers and / or communicate via different technologies.

[0085] UE 302 and base station 304 each include wireless wide area network (WWAN) transceivers 310 and 350, respectively, providing means (e.g., means for transmitting, means for receiving, means for measuring, means for tuning, means for suppressing transmission, etc.) for communication via one or more wireless communication networks (not shown) (such as NR networks, LTE networks, GSM networks, etc.). WWAN transceivers 310 and 350 may be connected to one or more antennas 316 and 356, respectively, for communication with other network nodes (such as other UEs, access points, base stations (e.g., eNB, gNB), etc.) over a wireless communication medium of interest (e.g., a time / frequency resource set in a specific spectrum) via at least one designated RAT (e.g., NR, LTE, GSM, etc.). WWAN transceivers 310 and 350 can be configured, according to a specified RAT, in various ways to transmit and encode signals 318 and 358 (e.g., messages, indications, information, etc.), and conversely, to receive and decode signals 318 and 358 (e.g., messages, indications, information, pilots, etc.). Specifically, WWAN transceivers 310 and 350 each include one or more transmitters 314 and 354 for transmitting and encoding signals 318 and 358, respectively, and each includes one or more receivers 312 and 352 for receiving and decoding signals 318 and 358, respectively.

[0086] In at least some cases, UE 302 and base station 304 also include wireless local area network (WLAN) transceivers 320 and 360, respectively. WLAN transceivers 320 and 360 can be connected to one or more antennas 326 and 366, respectively, and provide connectivity via at least one designated RAT (e.g., WiFi, LTE-D, etc.). A means for communicating with other network nodes (such as other UEs, access points, base stations, etc.) over a wireless communication medium of interest (e.g., means for transmitting, means for receiving, means for measuring, means for tuning, means for suppressing transmission, etc.). WLAN transceivers 320 and 360 can be configured, according to a specified RAT, in various ways to transmit and encode signals 328 and 368 (e.g., messages, indications, information, etc.), and conversely, to receive and decode signals 328 and 368 (e.g., messages, indications, information, pilots, etc.). Specifically, WLAN transceivers 320 and 360 each include one or more transmitters 324 and 364 for transmitting and encoding signals 328 and 368, respectively, and each includes one or more receivers 322 and 362 for receiving and decoding signals 328 and 368, respectively.

[0087] A transceiver circuit system including at least one transmitter and at least one receiver may, in some implementations, include integrated devices (e.g., transmitter and receiver circuitry implemented as a single communication device), in some implementations, include separate transmitter and receiver devices, or in other implementations, may be implemented in a different manner. In one aspect, the transmitter may include or be coupled to multiple antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array, which allows the corresponding device to perform transmit "beamforming," as described herein. Similarly, the receiver may include or be coupled to multiple antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array, which allows the corresponding device to perform receive beamforming, as described herein. In another aspect, the transmitter and receiver may share the same multiple antennas (e.g., antennas 316, 326, 356, 366) such that the corresponding device can only receive or transmit at a given time, rather than both simultaneously. The wireless communication equipment of UE 302 and / or base station 304 (e.g., one or both of transceivers 310 and 320 and / or one or both of transceivers 350 and 360) may also include a network eavesdropping module (NLM) for performing various measurements, etc.

[0088] In at least some cases, UE 302 and base station 304 also include Satellite Positioning System (SPS) receivers 330 and 370. SPS receivers 330 and 370 may be connected to one or more antennas 336 and 376, respectively, and may be provided with means for receiving and / or measuring SPS signals 338 and 378, such as Global Positioning System (GPS) signals, Global Navigation Satellite System (GLONASS) signals, Galileo signals, BeiDou signals, Indian Regional Navigation Satellite System (NAVIC), Quasi-Zenith Satellite System (QZSS), etc. SPS receivers 330 and 370 may each include any suitable hardware and / or software for receiving and processing SPS signals 338 and 378. SPS receivers 330 and 370 request information and operation from other systems as appropriate and perform necessary calculations to determine the positioning of UE 302 and base station 304 using measurements obtained by any suitable SPS algorithm.

[0089] Base station 304 and network entity 306 each include at least one network interface 380 and 390, providing means for communicating with other network entities (e.g., means for transmitting, means for receiving, etc.). For example, network interfaces 380 and 390 (e.g., one or more network access ports) may be configured to communicate with one or more network entities via a wired or wireless backhaul connection. In some aspects, network interfaces 380 and 390 may be implemented as transceivers configured to support wired or wireless signal communication. This communication may involve, for example, sending and receiving messages, parameters, and / or other types of information.

[0090] UE 302, base station 304, and network entity 306 also include other components that can be used in conjunction with operations disclosed herein. UE 302 includes a processor circuitry implemented with a processing system 332 for providing, for example, functionality related to wireless positioning, and for providing other processing functionality. Base station 304 includes a processing system 384 for providing, for example, functionality related to wireless positioning as disclosed herein, and for providing other processing functionality. Network entity 306 includes a processing system 394 for providing, for example, functionality related to wireless positioning as disclosed herein, and for providing other processing functionality. Processing systems 332, 384, and 394 can therefore provide means for processing, such as means for determining, means for calculating, means for receiving, means for transmitting, means for indicating, etc. In one aspect, processing systems 332, 384, and 394 may include, for example, one or more processors, such as one or more general-purpose processors, multi-core processors, ASICs, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), other programmable logic devices or processing circuitry, or various combinations thereof.

[0091] UE 302, base station 304, and network entity 306 include memory circuitry that implements memory components 340, 386, and 396 (e.g., each including a memory device) for maintaining information (e.g., information indicating reserved resources, thresholds, parameters, etc.). Memory components 340, 386, and 396 thus provide means for storage, means for retrieval, means for maintenance, etc. In some cases, UE 302, base station 304, and network entity 306 may include DDS modules 342, 388, and 398, respectively. DDS modules 342, 388, and 398 may be hardware circuitry as part of or coupled to processing systems 332, 384, and 394, which, when executed, cause UE 302, base station 304, and network entity 306 to perform the functionality described herein. In other respects, DDS modules 342, 388, and 398 may be external to processing systems 332, 384, and 394 (e.g., part of a modem processing system, integrated with another processing system, etc.). Alternatively, DDS modules 342, 388, and 398 may be memory modules stored in memory components 340, 386, and 396, respectively, which, when executed by processing systems 332, 384, and 394 (or a modem processing system, another processing system, etc.), enable UE 302, base station 304, and network entity 306 to perform the functionality described herein. Figure 3A The possible locations of the DDS module 342 are explained. The DDS module 342 may be part of the WWAN transceiver 310, memory component 340, processing system 332, or any combination thereof, or it may be a stand-alone component. Figure 3B The possible locations of the DDS module 388 are explained. The DDS module 388 may be part of a WWAN transceiver 350, a memory component 386, a processing system 384, or any combination thereof, or it may be a stand-alone component. Figure 3C The possible locations of the DDS module 398 are explained. The DDS module 398 may be part of (a) network interface 390, memory component 396, processing system 394, or any combination thereof, or may be a standalone component.

[0092] UE 302 may include one or more sensors 344 coupled to processing system 332 to provide means for sensing or detecting motion and / or orientation information independent of motion data derived from signals received by WWAN transceiver 310, WLAN transceiver 320, and / or SPS receiver 330. As an example, sensor 344 may include accelerometers (e.g., microelectromechanical systems (MEMS) devices), gyroscopes, geomagnetic sensors (e.g., compasses), altimeters (e.g., barometric altimeters), and / or any other type of motion detection sensor. Furthermore, sensor 344 may include multiple different types of devices and combine their outputs to provide motion information. For example, sensor 344 may use a combination of multi-axis accelerometers and orientation sensors to provide the ability to calculate positioning in 2D and / or 3D coordinate systems.

[0093] Additionally, UE 302 includes a user interface 346, which provides means for providing instructions to the user (e.g., audible and / or visual instructions) and / or for receiving user input (e.g., when the user actuates a sensing device (such as a keypad, touchscreen, microphone, etc.)). Although not shown, base station 304 and network entity 306 may also include user interfaces.

[0094] Referring more specifically to processing system 384, in the downlink, IP packets from network entity 306 can be provided to processing system 384. Processing system 384 can implement functionality for the RRC layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, and Media Access Control (MAC) layer. The processing system 384 can provide RRC layer functionality associated with broadcast system information (e.g., Master Information Block (MIB), System Information Block (SIB)), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-RAT mobility, and measurement configuration of UE measurement reports; PDCP layer functionality associated with header compression / decompression, security (cryptography, cryptographic decoding, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with upper-layer PDU delivery, error correction via Automatic Repeat Request (ARQ), concatenation, segmentation and reassembly of RLC Service Data Units (SDUs), resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel priority ordering.

[0095] Transmitter 354 and receiver 352 implement Layer 1 (L1) functionality associated with various signal processing functions. Layer-1, including the physical (PHY) layer, may include error detection on the transport channel, forward error correction (FEC) decoding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. Transmitter 354 processes the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The decoded and modulated symbols can then be split into parallel streams. Each stream can then be mapped to an orthogonal frequency division multiplexing (OFDM) subcarrier, multiplexed with a reference signal (e.g., a pilot) in the time and / or frequency domains, and subsequently combined using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time-domain OFDM symbol stream. The OFDM symbol stream is spatially precoded to generate multiple spatial streams. Channel estimates from the channel estimator can be used to determine the coding and modulation schemes, as well as for spatial processing. The channel estimates can be derived from reference signals transmitted by UE 302 and / or channel condition feedback. Each spatial stream can then be provided to one or more different antennas 356. Transmitter 354 can use the corresponding spatial stream to modulate an RF carrier for transmission.

[0096] At UE 302, receiver 312 receives signals via its corresponding antenna 316. Receiver 312 recovers the information modulated onto the RF carrier and provides this information to processing system 332. Transmitter 314 and receiver 312 implement Layer 1 functionality associated with various signal processing functions. Receiver 312 can perform spatial processing on this information to recover any spatial stream destined for UE 302. If multiple spatial streams are destined for UE 302, they can be combined by receiver 312 into a single OFDM symbol stream. Receiver 312 then uses a Fast Fourier Transform (FFT) to transform the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal consists of a separate OFDM symbol stream for each subcarrier of the OFDM signal. Symbols on each subcarrier, along with a reference signal, are recovered and demodulated by determining the signal constellation points most likely to be transmitted by base station 304. These soft decisions can be based on a channel estimate calculated by a channel estimator. These soft decisions are then decoded and deinterleaved to recover the original data and control signals transmitted by base station 304 on the physical channel. These data and control signals are then provided to processing system 332, which implements Layer 3 (L3) and Layer 2 (L2) functionality.

[0097] In the uplink, processing system 332 provides demultiplexing, packet reassembly, cipher decoding, header decompression, and control signal processing between the transport and logical channels to recover IP packets from the core network. Processing system 332 is also responsible for error detection.

[0098] Similar to the functionality described in conjunction with downlink transmissions performed by base station 304, processing system 332 provides RRC layer functionality associated with system information (e.g., MIB, SIB) capture, RRC connectivity, and measurement reporting; PDCP layer functionality associated with header compression / decompression and security (cryptography, cryptographic decoding, integrity protection, integrity verification); RLC layer functionality associated with upper-layer PDU delivery, error correction via ARQ, concatenation, segmentation and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing MAC SDUs onto transport blocks (TBs), demultiplexing MAC SDUs from TBs, scheduling information reporting, error correction via Hybrid Automatic Repeat Request (HARQ), priority handling, and logical channel priority ordering.

[0099] The channel estimate derived by the channel estimator from the reference signal or feedback transmitted by the base station 304 can be used by the transmitter 314 to select an appropriate coding and modulation scheme and to facilitate spatial processing. The spatial stream generated by the transmitter 314 can be provided to different antennas 316. The transmitter 314 can use the corresponding spatial stream to modulate the RF carrier for transmission.

[0100] Uplink transmissions are processed at base station 304 in a manner similar to that described in conjunction with the receiver function at UE 302. Receiver 352 receives signals via its corresponding antenna 356. Receiver 352 recovers the information modulated onto the RF carrier and provides this information to processing system 384.

[0101] In the uplink, processing system 384 provides demultiplexing, packet reassembly, cipher decoding, header decompression, and control signal processing between the transport and logical channels to recover IP packets from UE 302. IP packets from processing system 384 can then be provided to the core network. Processing system 384 is also responsible for error detection.

[0102] For convenience, UE 302, base station 304 and / or network entity 306 are in Figures 3A-3C The box is shown as including various components that can be configured according to the various examples described herein. However, it will be understood that the illustrated box may have different functionalities in different designs.

[0103] Various components of UE 302, base station 304 and network entity 306 can communicate with each other on data buses 334, 382 and 392 respectively. Figures 3A-3C The components can be implemented in various ways. In some implementations, Figures 3A-3C The components can be implemented in one or more circuits (for example, such as one or more processors and / or one or more ASICs (which may include one or more processors)). Here, each circuit may use and / or incorporate at least one memory component for storing information or executable code used by that circuit to provide this functionality. For example, some or all of the functionality represented by blocks 310 to 346 may be implemented by the processor and memory components of UE 302 (e.g., by executing appropriate code and / or by appropriately configuring the processor components). Similarly, some or all of the functionality represented by blocks 350 to 388 may be implemented by the processor and memory components of base station 304 (e.g., by executing appropriate code and / or by appropriately configuring the processor components). Furthermore, some or all of the functionality represented by blocks 390 to 398 may be implemented by the processor and memory components of network entity 306 (e.g., by executing appropriate code and / or by appropriately configuring the processor components). For simplicity, various operations, actions, and / or functions are described herein as being performed "by the UE," "by the base station," "by the network entity," etc. However, as will be appreciated, such operations, actions, and / or functions may actually be performed by specific components or combinations of components of the UE 302, base station 304, network entity 306, etc., such as processing systems 332, 384, 394, transceivers 310, 320, 350, and 360, memory components 340, 386, and 396, DDS modules 342, 388, and 398, etc.

[0104] Figure 4 The various Radio Resource Control (RRC) states available in the New Radio (NR) according to various aspects of this disclosure are explained.

[0105] Following the random access procedure, the UE is in the RRC connected state. The RRC protocol is used on the air interface between the UE and the base station. The main functions of the RRC protocol include connection establishment and release, broadcasting system information, radio bearer establishment, reconfiguration and release, RRC connection mobility procedure, paging notification and release, and outer loop power control. In LTE, the UE can be in one of two RRC states (connected or idle), but in NR, the UE can be in one of three RRC states (connected, idle, or inactive). Different RRC states have different radio resources associated with them, which the UE can use when in a given state. Note that the different RRC states are usually written in uppercase, as mentioned above; however, this is not mandatory, and these states can also be written in lowercase.

[0106] Figure 4 Figure 400 illustrates the different RRC states (also known as RRC modes) available in the NR according to various aspects of this disclosure. When the UE powers on, it is initially in the RRC DISCONNECTED / Idle state 410. After a random access procedure, the UE moves to the RRC Connected state 420. If the UE is inactive for a short period, it can suspend its session by moving to the RRC Inactive state 430. The UE can resume its session by executing a random access procedure to transition back to the RRC Connected state 420. Therefore, the UE needs to execute a random access procedure to transition to the RRC Connected state 420, regardless of whether the UE is in the RRC Idle state 410 or the RRC Inactive state 430.

[0107] Operations performed in RRC Idle State 410 include Public Land Mobile Network (PLMN) selection, broadcasting of system information, cell reselection mobility, paging for mobile termination data (initiated and managed by the 5GC), and Discontinuous Reception (DRX) for core network paging (configured by the Non-Access Stratum (NAS)). Operations performed in RRC Connectivity State 420 include 5GC (e.g., 5GC 260) and new RAN (e.g., new RAN 220) connection establishment (both control plane and user plane), UE context storage at the new RAN and UE, new RAN knowledge about the cell to which the UE belongs, passing unicast data to / from the UE, and network-controlled mobility. Operations performed in RRC inactive state 430 include broadcasting system information, cell reselection for mobility, paging (initiated by the new RAN), RAN-based notification area (RNA) management (performed by the new RAN), DRX for RAN paging (configured by the new RAN), 5GC for the UE and new RAN connection establishment (both control plane and user plane), storage of UE context in the new RAN and UE, and new RAN knowledge about the RNA to which the UE belongs.

[0108] Dual Subscriber Identity Module (SIM) Dual Standby (DSDS) communication devices can be configured with a first subscription (Sub1) as the default data subscription (DDS) (e.g., circuit-switched (CS) + packet-switched (PS)) and a second subscription (Sub2) as a non-DDS voice-only subscription (e.g., CS only). For example, a DSDS communication device can be configured with multiple 4G LTE SIMs (e.g., L+L), 4G LTE SIMs, and 5G NR SIMs, etc.

[0109] In some designs, packet data network (PDN) sessions can be passed from DDS Sub1 to non-DDS Sub2. For example, if a UE loses connectivity on DDS Sub1, it will subsequently have the option to switch to non-DDS Sub2 to receive PS traffic. Therefore, if downlink data (e.g., paging) is received on non-DDS Sub2, the PDN session pass (or DDS handover) from Sub1 to Sub2 allows Sub2 to receive downlink data.

[0110] Figure 5The DDS transition procedure 500 according to one aspect of this disclosure is explained. At 502, UE 302 switches from DDS Sub1 to non-DDS Sub2 (e.g., RF chains are reassigned from the RAT associated with DS Sub1 to the RAT associated with non-DDS Sub2). At 504, UE 302 transmits a PDN connectivity request via non-DDS Sub2 to a non-DDS Sub2 cell (e.g., BS 304, which may correspond to a 4G LTE eNB). At 506, the non-DDS Sub2 cell transmits an activation default EPS bearer context request to UE 302's non-DSSSub2. At 508, UE 302 switches from DDS Sub2 to non-DDS Sub1 (e.g., RF chains are reassigned from the RAT associated with non-DDS Sub2 to the RAT associated with non-DDS Sub1). At 510, UE 302's non-DDS Sub2 receives a paging indication. At 512, non-DDS Sub2 transitions to RRC connectivity. At 514, packet data arrives at UE 302 via non-DDS Sub2.

[0111] Paging at 510, RRC connection establishment at 512, and packet data arriving at 512 are problematic and may affect data services used for DDS Sub1. For example, since there may only be one RF chain (e.g., TX / RX) in a DSDS phone, packet data arriving on non-DDS Sub2 may cause data stagnation scenarios, which could affect various applications such as 5G-based gaming (e.g., users notice long latency, etc.).

[0112] Therefore, aspects of this disclosure relate to DSDS UEs that take proactive steps to dismantle packet data sessions from "old" RAT subscriptions (e.g., non-DDS Sub) after switching to a "new" RAT subscription (e.g., DDS Sub). Such aspects can provide various technical advantages, such as ensuring that packet data is routed to the appropriate RAT subscription (e.g., DDS Sub), which can help reduce or avoid the data stagnation issues mentioned above.

[0113] Figure 6 An exemplary process 600 for wireless communication according to one aspect of this disclosure is explained. Figure 6 The process 600 is executed by UE302.

[0114] In 610, UE 302 (e.g., DDS module 342, receiver 312 or 322, transmitter 314 or 324, processing system 332, etc.) transitions the packet data session from a first radio access technology (RAT) associated with a first subscription to a second RAT associated with a second subscription. In some designs, the first subscription is a DDS subscription and the second subscription is a non-DDS subscription. In other designs, the first subscription is a non-DDS subscription and the second subscription is a DDS subscription.

[0115] At 620, UE 302 (e.g., transmitter 314 or 324, etc.) transmits one or more messages over the first RAT to terminate the packet data session over the first RAT in response to a transition of the packet data session to the second RAT. In some designs, the messages(s) transmitted at 620 may vary depending on the implementation and / or RAT type, which will be described in more detail below.

[0116] refer to Figure 6 In some designs, the first RAT and the second RAT can be different. For example, the first RAT can correspond to 4G Long Term Evolution (LTE), and the second RAT can correspond to 5G New Radio (NR). In other designs, the first RAT and the second RAT can be the same. For example, the first RAT and the second RAT can be 4G LTE, or the first RAT and the second RAT can be 5G NR.

[0117] refer to Figure 6 In some designs, downlink packet data can be received via the first RAT after the packet data session transitions to the second RAT, which can trigger the transmission of one or more messages at 620. In other designs, the transmission of these one or more messages at 620 is triggered directly based on the packet data session transition to the second RAT.

[0118] refer to Figure 6 In some designs where the first RAT is 4G Long Term Evolution (LTE), the one or more messages may include a Packet Data Network (PDN) disconnection request. In further designs, the one or more messages may include a PDC connectivity request message following the PDN disconnection request. In other designs where the first RAT is 4G Long Term Evolution (LTE), the one or more messages may include a Tracking Area Update (TAU) with an Evolved Packet System (EPS) Identifier (ID) set to false.

[0119] refer to Figure 6 In some designs where the first RAT is 5G NR, the one or more messages may include a Packet Data Unit (PDU) session release request, a PDU session release completion request, and a PDU session establishment request.

[0120] Figure 7 Explanation based on one aspect of this disclosure Figure 6 The example implementation of process 600 is 700. Figure 7 In the example, Sub1 corresponds to DDS, and Sub2 corresponds to non-DDS, and both Sub1 and Sub2 are associated with the same 4G LTERAT type. 702-714 corresponds to... Figure 5 Sections 502-514 will not be described further for brevity. At 716, in response to packet data arriving on the non-DDS Sub2 at 714, UE 302 terminates the PDN session. Specifically, UE 302 sends a PDN disconnect request to the non-DDS Sub2 cell (e.g., 4G LTE eNB) at 716, the non-DDS Sub2 cell (e.g., 4G LTE eNB) sends a disable EPS bearer context request to UE 302's non-DDS Sub2 cell at 718, and UE 302 sends a disable EPS bearer context acceptance to the non-DDS Sub2 cell (e.g., 4G LTE eNB) at 720. By terminating the PDN session on the non-DDS Sub2 in this manner, future packet traffic will be routed to UE 302 via DDS Sub1 instead of the non-DDS Sub2.

[0121] Figure 8 This explains another aspect of the disclosure. Figure 6 The example implementation of process 600 is 800. Figure 8 In the example, Sub1 corresponds to DDS, and Sub2 corresponds to non-DDS, and both Sub1 and Sub2 are associated with the same 4G LTE RAT type. 802-808 correspond to... Figure 5 Sections 502-508 will not be described further for brevity. At 810, instead of waiting to see if the network will actually continue routing packet data through non-DDS Sub2, UE 302 actively tears up its packet data session through non-DDS Sub2 (e.g., during or shortly after the DDS handover at 808). Specifically, at 810, UE 302 transmits a TAU with an Internet EPS ID set to spurious, and at 812, the non-DDS Sub2 cell responds with a TAU acceptance. The TAU procedure at 810-812 is used to clear the PS context between the network and non-DDS Sub2 (e.g., because non-DDS Sub2 does not require an Internet connection when DDS Sub1 is available).

[0122] Figure 9 This explains another aspect of the disclosure. Figure 6The example implementation of process 600 is 900. Figure 9 In the example, Sub1 corresponds to DDS, and Sub2 corresponds to non-DDS, and both Sub1 and Sub2 are associated with the same 4G LTE RAT type. 902-808 corresponds to... Figure 5 Sections 502-508 will not be described further for the sake of brevity. At 910, instead of waiting to see if the network will actually continue routing packet data via non-DDS Sub2, UE 302 actively tears up its packet data session via non-DDS Sub2 (e.g., during or shortly after the DDS handover at 908). Specifically, UE 302 sends a PDN disconnect request to the non-DDS Sub2 cell (e.g., 4G LTE eNB) at 910, the non-DDS Sub2 cell (e.g., 4G LTE eNB) sends a disable EPS bearer context request to UE 302's non-DDS Sub2 cell at 912, and UE 302 sends a disable EPS bearer context acceptance to the non-DDS Sub2 cell (e.g., 4G LTE eNB) at 914. UE 302 then transmits a PDN connectivity request to a non-DDS Sub2 cell (e.g., a 4G LTE eNB) at 916. The non-DDS Sub2 cell (e.g., a 4G LTE eNB) transmits an Activate EPS Bearer Context request to UE 302's non-DDS Sub2 cell at 918, and UE 302 transmits an Activate EPS Bearer Context Acceptance to the non-DDS Sub2 cell (e.g., a 4G LTE eNB) at 920. By dismantling (and subsequently re-establishing) the PDN session on the non-DDS Sub2 cell, future packet traffic will be routed to UE 302 via DDS Sub1 instead of the non-DDS Sub2 cell.

[0123] Figure 10 This explains another aspect of the disclosure. Figure 6 The process 600 is an example implementation of 1000. Figure 10 In the example, Sub1 corresponds to DDS, and Sub2 corresponds to non-DDS, and Sub1 and Sub2 are associated with different RAT types (e.g., 5G NR and 4G LTE, respectively). Besides the different RAT types of Sub1 and Sub2, Figure 10 Process 1000 in other aspects and Figure 8 The process is the same as 800, and for the sake of brevity, it will not be described further.

[0124] Figure 11 This explains another aspect of the disclosure. Figure 6 Example implementation of process 600 is 1100. Figure 11 In the example, Sub1 corresponds to DDS, and Sub2 corresponds to non-DDS, and Sub1 and Sub2 are associated with different RAT types (e.g., 5G NR and 4G LTE, respectively). Besides the different RAT types of Sub1 and Sub2, Figure 11 Process 1100 in other aspects and Figure 9 The process is the same as 900, and for the sake of brevity, it will not be described further.

[0125] Figure 12 This explains another aspect of the disclosure. Figure 6 The example implementation of process 600 is 1200. Figure 12 In the example, Sub1 corresponds to DDS, and Sub2 corresponds to non-DDS, and both Sub1 and Sub2 are associated with the same 5G NR RAT type.

[0126] At 1202, UE 302 switches from DDS Sub1 to non-DDS Sub2 (e.g., the RF chains are reassigned from the RAT associated with DDS Sub1 to the RAT associated with non-DDS Sub2). At 504, UE 302 transmits 5G registration via non-DDS Sub2 to a non-DDS Sub2 cell (e.g., BS 304, which may correspond to a 5G NR gNB). At 1206, the non-DDS Sub2 cell transmits 5G registration acceptance to UE 302's non-DSS Sub2. At 1208, UE 302 switches from DDS Sub2 to non-DDS Sub1 (e.g., the RF chains are reassigned from the RAT associated with non-DDS Sub2 to the RAT associated with non-DDS Sub1). At 1210, UE 302's non-DDS Sub2 receives a paging indication.

[0127] At 1210, instead of waiting to see if the network will actually continue routing packet data via non-DDS Sub2, UE302 actively tears down its packet data session via non-DDS Sub2 (e.g., during or shortly after a DDS handover at 1208). Specifically, UE302 sends a PDU session release request to the non-DDS Sub2 cell (e.g., 5G BR gNB) at 1210, the non-DDS Sub2 cell (e.g., 5G NR gNB) sends a PDU session release command to UE302's non-DDS Sub2 cell at 1212, and UE302 sends a PDU session release acceptance to the non-DDS Sub2 cell (e.g., 5G NR gNB) at 1214. UE 302 then transmits a PDU session establishment request to a non-DDS Sub2 cell (e.g., a 5G NR gNB) at 1216, and the non-DDS Sub2 cell (e.g., a 4G LTE eNB) transmits a PDU session establishment acceptance to UE 302's non-DDS Sub2 cell at 1218. By dismantling (and subsequently re-establishing) the PDU session on the non-DDS Sub2 cell in this manner, future packet traffic will be routed to UE 302 via DDS Sub1 instead of the non-DDS Sub2 cell.

[0128] Although Figure 7-12 The examples each relate to a switch from a non-DDS Sub2 to a DDS Sub1 that (directly or indirectly) triggers the teardown of a delayed data session on the non-DDS Sub2, but it will be appreciated that the aspects alternatively relate to scenarios where a data session is torn down on a DDS Sub1 in response to a transition (or switch) to a non-DDS Sub2.

[0129] In the detailed description above, it can be seen that different features are grouped together in the examples. This manner of disclosure should not be construed as an intention to have more features than those explicitly mentioned in each clause. Rather, aspects of this disclosure may include fewer features than those of the individual example clauses disclosed. Therefore, the appended clauses should thus be considered as incorporated into this description, where each clause may be a separate example. Although each dependent clause may refer in its respective clause to a specific combination with one of the other clauses, the aspects of that dependent clause are not limited to that specific combination. It will be appreciated that other example clauses may also include combinations of aspects of the dependent clause with the subject matter of any other dependent or independent clause, or any feature combined with other dependent and independent clauses. The aspects disclosed herein expressly include these combinations unless explicitly stated or readily inferred that a particular combination is not intended (e.g., contradictory aspects, such as defining an element as both an insulator and a conductor). Furthermore, it is intended that aspects of a clause may be included in any other independent clause, even if that clause is not directly subordinate to that independent clause.

[0130] Examples of implementations are described in the following numbered clauses:

[0131] In the detailed description above, it can be seen that different features are grouped together in the examples. This manner of disclosure should not be construed as an intention to have more features than those explicitly mentioned in each clause. Rather, aspects of this disclosure may include fewer features than those of the individual example clauses disclosed. Therefore, the appended clauses should thus be considered as incorporated into this description, where each clause may be a separate example. Although each dependent clause may refer in its respective clause to a specific combination with one of the other clauses, the aspects of that dependent clause are not limited to that specific combination. It will be appreciated that other example clauses may also include combinations of aspects of the dependent clause with the subject matter of any other dependent or independent clause, or any feature combined with other dependent and independent clauses. The aspects disclosed herein expressly include these combinations unless explicitly stated or readily inferred that a particular combination is not intended (e.g., contradictory aspects, such as defining an element as both an insulator and a conductor). Furthermore, it is intended that aspects of a clause may be included in any other independent clause, even if that clause is not directly subordinate to that independent clause.

[0132] Examples of implementations are described in the following numbered clauses:

[0133] Clause 1. A wireless communication method performed by a dual subscriber identity module (SIM) dual standby (DSDS) user equipment (UE), comprising: switching a packet data session from a first radio access technology (RAT) associated with a first subscription to a second RAT associated with a second subscription; and transmitting one or more messages via the first RAT to terminate the packet data session via the first RAT in response to the switching of the packet data session to the second RAT.

[0134] Clause 2. The method of Clause 1, wherein the first subscription is a default data subscription (DDS) subscription and the second subscription is a non-DDS subscription.

[0135] Clause 3. The method of any one of Clauses 1 to 2, wherein the first subscription is a non-default data subscription (DDS) subscription and the second subscription is a DDS subscription.

[0136] Clause 4. The method of any of Clauses 1 to 3, wherein the first RAT and the second RAT are different.

[0137] Clause 5. The method of Clause 4, wherein the first RAT is 4G Long Term Evolution (LTE) and the second RAT is 5G New Radio (NR).

[0138] Clause 6. The method of any of Clauses 1 to 5, wherein the first RAT and the second RAT are the same.

[0139] Clause 7. The method as described in Clause 6, wherein the first RAT and the second RAT are 4G Long Term Evolution (LTE).

[0140] Clause 8. The method of any one of Clauses 6 to 7, wherein the first RAT and the second RAT are 5G New Radio (NR).

[0141] Clause 9. The method of any one of Clauses 1 to 8 further includes: receiving downlink packet data via a first RAT after the packet data session transitions to a second RAT, wherein the transmission of the one or more messages is triggered in response to the received downlink packet data.

[0142] Clause 10. The method of any one of Clauses 1 to 9, wherein the transmission of the one or more messages is directly triggered based on the transition of the packet data session to the second RAT.

[0143] Clause 11. The method of any one of Clauses 1 to 10, wherein the first RAT is 4G Long Term Evolution (LTE).

[0144] Clause 12. The method of Clause 11, wherein the one or more messages include a Packet Data Network (PDN) disconnection request.

[0145] Clause 13. The method of any one of Clauses 11 to 12, wherein the one or more messages further include a PDC connectivity request message following the PDN disconnection request.

[0146] Clause 14. The method of any one of Clauses 11 to 13, wherein the one or more messages include a Tracking Area Update (TAU) having an Evolved Packet System (EPS) identifier (ID) set to false.

[0147] Clause 15. The method of any one of Clauses 1 to 14, wherein the first RAT is 5G New Radio (NR).

[0148] Clause 16. The method of Clause 15, wherein the one or more messages include a Packet Data Unit (PDU) session release request, a PDU session release completion, and a PDU session establishment request.

[0149] Clause 17. An apparatus comprising: a memory and at least one processor communicatively coupled to the memory, the memory and the at least one processor being configured to perform a method according to any one of Clauses 1 to 16.

[0150] Clause 18. An apparatus comprising means for performing a method as described in any of Clauses 1 to 16.

[0151] Clause 19. A non-transient computer-readable medium storing computer-executable instructions, including at least one instruction for causing a computer or processor to perform a method as described in any one of Clauses 1 to 16.

[0152] Those skilled in the art will appreciate that information and signals can be represented using any of a variety of different techniques and skills. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or light particles, or any combination thereof.

[0153] Furthermore, those skilled in the art will appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in connection with the aspects disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps are described above in a generalized manner in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in different ways for each specific application, but such implementation decisions should not be construed as departing from the scope of this disclosure.

[0154] The various illustrative logic blocks, modules, and circuits described in conjunction with the aspects disclosed herein can be implemented or executed using a general-purpose processor, DSP, ASIC, FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but in alternatives, it may be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration.

[0155] The methods, sequences, and / or algorithms described in conjunction with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of both. The software module may reside in random access memory (RAM), flash memory, read-only memory (ROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium known in the art. Example storage media are coupled to a processor so that the processor can read and write information from / to the storage medium. In alternatives, the storage medium may be integrated into the processor. The processor and storage medium may reside in an ASIC. The ASIC may reside in a user terminal (e.g., a UE). In alternatives, the processor and storage medium may reside as discrete components in the user terminal.

[0156] In one or more examples, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functionality may be stored or transmitted as one or more instructions or codes on or through a computer-readable medium. A computer-readable medium includes both computer storage media and communication media, including any medium that facilitates the transfer of a computer program from one location to another. A storage medium may be any available medium accessible to a computer. By way of example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and is accessible to a computer. Similarly, any connection is also legitimately referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then such coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. As used in this article, disks and discs include compact discs (CDs), laser discs, optical discs, digital multi-purpose discs (DVDs), floppy disks, and Blu-ray discs. Disks typically reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of these should also be included within the scope of computer-readable media.

[0157] While the foregoing disclosure has illustrated illustrative aspects of this disclosure, it should be noted that various changes and modifications may be made therein without departing from the scope of this disclosure as defined by the appended claims. The functions, steps, and / or actions in the method claims according to the aspects of this disclosure described herein need not be performed in any particular order. Furthermore, although elements of this disclosure may be described or claimed in the singular, pluralism is also contemplated unless explicitly stated to be limited to the singular.

Claims

1. A wireless communication method executed by a dual subscriber identity module (SIM dual standby DSDS user equipment) UE, comprising: The packet data session is transferred from the first radio access technology (RAT) associated with the first subscription to the second RAT associated with the second subscription; as well as In response to the packet data session transitioning to the second RAT, one or more messages are transmitted over the first RAT to terminate the packet data session transmitted over the first RAT.

2. The method of claim 1, wherein the first subscription is a default data subscription DDS subscription, and the second subscription is a non-DDS subscription.

3. The method of claim 1, wherein the first subscription is a non-default data subscription DDS subscription, and the second subscription is a DDS subscription.

4. The method of claim 1, wherein the first RAT and the second RAT are different.

5. The method of claim 4, wherein the first RAT is 4G Long Term Evolution (LTE) and the second RAT is 5G New Radio (NR).

6. The method of claim 1, wherein the first RAT and the second RAT are identical.

7. The method of claim 6, wherein the first RAT and the second RAT are 4G Long Term Evolution (LTE).

8. The method of claim 6, wherein the first RAT and the second RAT are 5G New Radio (NR).

9. The method of claim 1, further comprising: After the packet data session transitions to the second RAT, downlink packet data is received through the first RAT. The transmission of one or more of the aforementioned messages is triggered in response to received downlink packet data.

10. The method of claim 1, wherein the transmission of one or more messages is directly triggered based on the transition of the packet data session to the second RAT.

11. The method of claim 1, wherein the first RAT is 4G Long Term Evolution (LTE).

12. The method of claim 11, wherein the one or more messages include a Packet Data Network (PDN) disconnection request.

13. The method of claim 12, wherein the one or more messages further include a PDC connectivity request message following the PDN disconnection request.

14. The method of claim 11, wherein the one or more messages include a Tracking Area Update (TAU) having an Evolved Packet System (EPS) identifier ID set to false.

15. The method of claim 1, wherein the first RAT is a 5G New Radio (NR).

16. The method of claim 15, wherein the one or more messages include a Packet Data Unit (PDU) session release request, a PDU session release completion, and a PDU session establishment request.

17. A dual-subscriber identity module (SIM dual-standby DSDS) user equipment (UE), comprising: Memory; At least one transceiver; as well as At least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: The packet data session is transferred from the first radio access technology (RAT) associated with the first subscription to the second RAT associated with the second subscription; and In response to the packet data session transitioning to the second RAT, one or more messages are transmitted over the first RAT to terminate the packet data session transmitted over the first RAT.

18. The DSDS UE of claim 17, wherein the first subscription is a default data subscription DDS subscription, and the second subscription is a non-DDS subscription.

19. The DSDS UE of claim 17, wherein the first subscription is a non-default data subscription DDS subscription, and the second subscription is a DDS subscription.

20. The DSDS UE of claim 17, wherein the first RAT and the second RAT are different.

21. The DSDS UE of claim 20, wherein the first RAT is 4G Long Term Evolution (LTE) and the second RAT is 5G New Radio (NR).

22. The DSDS UE of claim 17, wherein the first RAT and the second RAT are identical.

23. The DSDS UE as claimed in claim 22, wherein the first RAT and the second RAT are 4G Long Term Evolution (LTE).

24. The DSDS UE of claim 22, wherein the first RAT and the second RAT are 5G New Radio (NR).

25. The DSDS UE of claim 17, wherein the at least one processor is further configured to: After the packet data session transitions to the second RAT, downlink packet data is received through the first RAT. The transmission of one or more of the aforementioned messages is triggered in response to received downlink packet data.

26. The DSDS UE of claim 17, wherein the transmission of one or more messages is directly triggered based on the packet data session transition to the second RAT.

27. The DSDS UE as claimed in claim 17, wherein the first RAT is 4G Long Term Evolution (LTE).

28. The DSDS UE of claim 27, wherein one or more messages include a Packet Data Network (PDN) disconnection request.

29. The DSDS UE of claim 28, wherein the one or more messages further include a PDC connectivity request message following the PDN disconnection request.

30. The DSDS UE of claim 27, wherein the one or more messages include a Tracking Area Update (TAU) having an Evolved Packet System EPS Identifier ID set to false.

31. The DSDS UE as claimed in claim 17, wherein the first RAT is a 5G New Radio (NR).

32. The DSDS UE of claim 31, wherein the one or more messages include a Packet Data Unit (PDU) session release request, a PDU session release completion, and a PDU session establishment request.

33. A subscriber identity module (SIM dual standby DSDS user equipment) UE, comprising: A means for switching a packet data session from a first radio access technology (RAT) associated with a first subscription to a second RAT associated with a second subscription; as well as A means for transmitting one or more messages over the first RAT in response to a transition of the packet data session to the second RAT to terminate the packet data session over the first RAT.

34. The DSDS UE of claim 33, wherein the first subscription is a default data subscription DDS subscription, and the second subscription is a non-DDS subscription.

35. The DSDS UE of claim 33, wherein the first subscription is a non-default data subscription DDS subscription, and the second subscription is a DDS subscription.

36. The DSDS UE of claim 33, wherein the first RAT and the second RAT are different.

37. The DSDS UE of claim 36, wherein the first RAT is 4G Long Term Evolution (LTE) and the second RAT is 5G New Radio (NR).

38. The DSDS UE of claim 33, wherein the first RAT and the second RAT are identical.

39. The DSDS UE as claimed in claim 38, wherein the first RAT and the second RAT are 4G Long Term Evolution (LTE).

40. The DSDS UE of claim 38, wherein the first RAT and the second RAT are 5G New Radio (NR).

41. The DSDS UE as claimed in claim 33, further comprising: A means for receiving downlink packet data via the first RAT after the packet data session has transitioned to the second RAT. The transmission of one or more of the aforementioned messages is triggered in response to received downlink packet data.

42. The DSDS UE of claim 33, wherein the transmission of one or more messages is directly triggered based on the packet data session transition to the second RAT.

43. The DSDS UE as claimed in claim 33, wherein the first RAT is 4G Long Term Evolution (LTE).

44. The DSDS UE of claim 43, wherein one or more messages include a Packet Data Network (PDN) disconnection request.

45. The DSDS UE of claim 44, wherein the one or more messages further include a PDC connectivity request message following the PDN disconnection request.

46. ​​The DSDS UE of claim 43, wherein the one or more messages include a Tracking Area Update (TAU) having an Evolved Packet System EPS Identifier ID set to false.

47. The DSDS UE of claim 33, wherein the first RAT is a 5G New Radio (NR).

48. The DSDS UE of claim 47, wherein the one or more messages include a Packet Data Unit (PDU) session release request, a PDU session release completion, and a PDU session establishment request.

49. A non-transient computer-readable medium storing an instruction set, the instruction set comprising one or more instructions, said one or more instructions causing the DSDS UE, when executed by one or more processors of a Dual Subscriber Identity Module (SIM Dual Standby DSDS User Equipment) UE: The packet data session is transferred from the first radio access technology (RAT) associated with the first subscription to the second RAT associated with the second subscription; and In response to the packet data session transitioning to the second RAT, one or more messages are transmitted over the first RAT to terminate the packet data session transmitted over the first RAT.

50. The non-transient computer-readable medium of claim 49, wherein the first subscription is a default data subscription (DDS) subscription, and the second subscription is a non-DDS subscription.

51. The non-transient computer-readable medium of claim 49, wherein the first subscription is a non-default data subscription (DDS) subscription, and the second subscription is a DDS subscription.

52. The non-transient computer-readable medium of claim 49, wherein the first RAT and the second RAT are different.

53. The non-transient computer-readable medium of claim 52, wherein the first RAT is 4G Long Term Evolution (LTE) and the second RAT is 5G New Radio (NR).

54. The non-transient computer-readable medium of claim 49, wherein the first RAT and the second RAT are identical.

55. The non-transient computer-readable medium of claim 54, wherein the first RAT and the second RAT are 4G Long Term Evolution (LTE).

56. The non-transient computer-readable medium of claim 54, wherein the first RAT and the second RAT are 5G New Radio (NR).

57. The non-transient computer-readable medium of claim 49, wherein the instructions, when executed, further cause the DSDS UE to: After the packet data session transitions to the second RAT, downlink packet data is received through the first RAT. The transmission of one or more of the aforementioned messages is triggered in response to received downlink packet data.

58. The non-transient computer-readable medium of claim 49, wherein the transmission of one or more messages is directly triggered based on the transition of the packet data session to the second RAT.

59. The non-transient computer-readable medium of claim 49, wherein the first RAT is 4G Long Term Evolution (LTE).

60. The non-transient computer-readable medium of claim 59, wherein the one or more messages include a Packet Data Network (PDN) disconnection request.

61. The non-transient computer-readable medium of claim 60, wherein the one or more messages further include a PDC connectivity request message following the PDN disconnection request.

62. The non-transient computer-readable medium of claim 59, wherein the one or more messages include a Tracking Area Update (TAU) having an Evolved Packet System (EPS) identifier ID set to false.

63. The non-transient computer-readable medium of claim 49, wherein the first RAT is a 5G New Radio (NR).

64. The non-transient computer-readable medium of claim 63, wherein the one or more messages include a Packet Data Unit (PDU) session release request, a PDU session release completion, and a PDU session establishment request.

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