WO2022006855A1

WO2022006855A1 - Avoid registration in standalone mode for non-standalone subscriber

Info

Publication number: WO2022006855A1
Application number: PCT/CN2020/101346
Authority: WO
Inventors: Hao Zhang; Jian Li; Tianya LIN
Original assignee: Qualcomm Incorporated
Priority date: 2020-07-10
Filing date: 2020-07-10
Publication date: 2022-01-13

Abstract

A configuration to allow a UE to disable SA mode for a period of time when SA registration has failed in order to avoid additional SA service request failures. The apparatus sends a first registration request to a first network, wherein the first registration request indicates one or more network services subscribed to by the UE. The apparatus determines whether a first registration response is received from the first network within a first timer. The first registration request has failed when the first registration response from the first network is not received prior to the expiration of the first timer. The apparatus starts a second timer in response to the UE not receiving the first registration response from the first network prior to the expiration of the first timer. At least one network service of the UE is disabled for at least a portion of a duration of the second timer. The apparatus sends a second registration request to a second network. The apparatus receives a second registration response from the second network.

Description

AVOID REGISTRATION IN STANDALONE MODE FOR NON-STANDALONE SUBSCRIBER

BACKGROUND Technical Field

The present disclosure relates generally to communication systems, and more particularly, to a configuration to avoid registration in standalone (SA) mode for a non-standalone (NSA) subscriber.

Introduction

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G New Radio (NR) . 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT) ) , and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB) , massive machine type communications (mMTC) , and ultra-reliable low latency communications (URLLC) . Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.

SUMMARY

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a device at a UE. The device may be a processor and/or a modem at a UE or the UE itself. The apparatus sends a first registration request to a first network, wherein the first registration request indicates one or more network services subscribed to by the UE. The apparatus determines whether a first registration response is received from the first network within a first timer. The first registration request has failed when the first registration response from the first network is not received prior to the expiration of the first timer. The apparatus starts a second timer in response to the UE not receiving the first registration response from the first network prior to the expiration of the first timer. At least one network service of the UE is disabled for at least a portion of a duration of the second timer. The apparatus sends a second registration request to a second network. The apparatus receives a second registration response from the second network.

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network.

FIG. 2A is a diagram illustrating an example of a first frame, in accordance with various aspects of the present disclosure.

FIG. 2B is a diagram illustrating an example of DL channels within a subframe, in accordance with various aspects of the present disclosure.

FIG. 2C is a diagram illustrating an example of a second frame, in accordance with various aspects of the present disclosure.

FIG. 2D is a diagram illustrating an example of UL channels within a subframe, in accordance with various aspects of the present disclosure.

FIG. 3 is a diagram illustrating an example of a base station and user equipment (UE) in an access network.

FIG. 4 is a call flow diagram of signaling between a UE, a first network, and a second network in accordance with certain aspects of the disclosure.

FIG. 5 is a flowchart of a method of wireless communication.

FIG. 6 is a diagram illustrating an example of a hardware implementation for an example apparatus.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements” ) . These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs) , central processing units (CPUs) , application processors, digital signal processors (DSPs) , reduced instruction set computing (RISC) processors, systems on a chip (SoC) , baseband processors, field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM) , a read-only memory (ROM) , an electrically erasable programmable ROM (EEPROM) , optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.

FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network 100. The wireless communications system (also referred to as a wireless wide area network (WWAN) ) includes base stations 102, UEs 104, an Evolved Packet Core (EPC) 160, and another core network 190 (e.g., a 5G Core (5GC) ) . The base stations 102 may include macrocells (high power cellular base station) and/or small cells (low power cellular base station) . The macrocells include base stations. The small cells include femtocells, picocells, and microcells.

The base stations 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) ) may interface with the EPC 160 through first backhaul links 132 (e.g., S1 interface) . The base stations 102 configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN) ) may interface with core network 190 through second backhaul links 184. In addition to other functions, the base stations 102 may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity) , inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS) , subscriber and equipment trace, RAN information management (RIM) , paging, positioning, and delivery of warning messages. The base stations 102 may communicate directly or indirectly (e.g., through the EPC 160 or core network 190) with each other over third backhaul links 134 (e.g., X2 interface) . The first backhaul links 132, the second backhaul links 184, and the third backhaul links 134 may be wired or wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, the small cell 102′may have a coverage area 110′that overlaps the coverage area 110 of one or more macro base stations 102. A network that includes both small cell and macrocells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs) , which may provide service to a restricted group known as a closed subscriber group (CSG) . The communication links 120 between the base stations 102 and the UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and/or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations 102 /UEs 104 may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL) . The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell) .

Certain UEs 104 may communicate with each other using device-to-device (D2D) communication link 158. The D2D communication link 158 may use the DL/UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , and a physical sidelink control channel (PSCCH) . D2D communication may be through a variety of wireless D2D communications systems, such as for example, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

The wireless communications system may further include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154, e.g., in a 5 GHz unlicensed frequency spectrum or the like. When communicating in an unlicensed frequency spectrum, the STAs 152 /AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.

The small cell 102′may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102′may employ NR and use the same unlicensed frequency spectrum (e.g., 5 GHz, or the like) as used by the Wi-Fi AP 150. The small cell 102′, employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network.

The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz -7.125 GHz) and FR2 (24.25 GHz -52.6 GHz) . The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz -300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band.

With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like if used herein may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, or may be within the EHF band.

A base station 102, whether a small cell 102′or a large cell (e.g., macro base station) , may include and/or be referred to as an eNB, gNodeB (gNB) , or another type of base station. Some base stations, such as gNB 180 may operate in a traditional sub 6 GHz spectrum, in millimeter wave frequencies, and/or near millimeter wave frequencies in communication with the UE 104. When the gNB 180 operates in millimeter wave or near millimeter wave frequencies, the gNB 180 may be referred to as a millimeter wave base station. The millimeter wave base station 180 may utilize beamforming 182 with the UE 104 to compensate for the path loss and short range. The base station 180 and the UE 104 may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming.

The base station 180 may transmit a beamformed signal to the UE 104 in one or more transmit directions 182′. The UE 104 may receive the beamformed signal from the base station 180 in one or more receive directions 182" . The UE 104 may also transmit a beamformed signal to the base station 180 in one or more transmit directions. The base station 180 may receive the beamformed signal from the UE 104 in one or more receive directions. The base station 180 /UE 104 may perform beam training to determine the best receive and transmit directions for each of the base station 180 /UE 104. The transmit and receive directions for the base station 180 may or may not be the same. The transmit and receive directions for the UE 104 may or may not be the same.

The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation as well as other functions. The PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176. The IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and/or other IP services. The BM-SC 170 may provide functions for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN) , and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS traffic to the base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information.

The core network 190 may include a Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. The AMF 192 may be in communication with a Unified Data Management (UDM) 196. The AMF 192 is the control node that processes the signaling between the UEs 104 and the core network 190. Generally, the AMF 192 provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF 195. The UPF 195 provides UE IP address allocation as well as other functions. The UPF 195 is connected to the IP Services 197. The IP Services 197 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a Packet Switch (PS) Streaming (PSS) Service, and/or other IP services.

The base station may include and/or be referred to as a gNB, Node B, eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , a transmit reception point (TRP) , or some other suitable terminology. The base station 102 provides an access point to the EPC 160 or core network 190 for a UE 104. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA) , a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player) , a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc. ) . The UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

Referring again to FIG. 1, in certain aspects, the UE 104 may be configured to disable SA mode for a period of time when SA registration has failed in order to avoid additional SA service request failures. For example, the UE 104 may comprise a timer component 198 configured to start a timer such that at least one network service of the UE 104 is disabled for at least a portion of the duration of the second timer. The UE 104 sends a first registration request to a first network, wherein the first registration request indicates one or more network services subscribed to by the UE 104. The UE 104 determines whether a first registration response is received from the first network within a first timer. The first registration request has failed when the first registration response from the first network is not received prior to the expiration of the first timer. The UE 104 starts a second timer in response to the UE 104 not receiving the first registration response from the first network prior to the expiration of the first timer. At least one network service of the UE 104 is disabled for at least a portion of a duration of the second timer. The UE 104 sends a second registration request to a second network. The UE 104 receives a second registration response from the second network.

Although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

FIG. 2A is a diagram 200 illustrating an example of a first subframe within a 5G NR frame structure. FIG. 2B is a diagram 230 illustrating an example of DL channels within a 5G NR subframe. FIG. 2C is a diagram 250 illustrating an example of a second subframe within a 5G NR frame structure. FIG. 2D is a diagram 280 illustrating an example of UL channels within a 5G NR subframe. The 5G NR frame structure may be frequency division duplexed (FDD) in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for either DL or UL, or may be time division duplexed (TDD) in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for both DL and UL. In the examples provided by FIGs. 2A, 2C, the 5G NR frame structure is assumed to be TDD, with subframe 4 being configured with slot format 28 (with mostly DL) , where D is DL, U is UL, and F is flexible for use between DL/UL, and subframe 3 being configured with slot format 34 (with mostly UL) . While

subframes

3, 4 are shown with slot formats 34, 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. UEs are configured with the slot format (dynamically through DL control information (DCI) , or semi-statically/statically through radio resource control (RRC) signaling) through a received slot format indicator (SFI) . Note that the description infra applies also to a 5G NR frame structure that is TDD.

Other wireless communication technologies may have a different frame structure and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms) . Each subframe may include one or more time slots. Subframes may also include mini-slots, which may include 7, 4, or 2 symbols. Each slot may include 7 or 14 symbols, depending on the slot configuration. For slot configuration 0, each slot may include 14 symbols, and for slot configuration 1, each slot may include 7 symbols. The symbols on DL may be cyclic prefix (CP) OFDM (CP-OFDM) symbols. The symbols on UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also referred to as single carrier frequency-division multiple access (SC-FDMA) symbols) (for power limited scenarios; limited to a single stream transmission) . The number of slots within a subframe is based on the slot configuration and the numerology. For slot configuration 0, different numerologies μ 0 to 4 allow for 1, 2, 4, 8, and 16 slots, respectively, per subframe. For slot configuration 1, different numerologies 0 to 2 allow for 2, 4, and 8 slots, respectively, per subframe. Accordingly, for slot configuration 0 and numerology μ, there are 14 symbols/slot and 2 ^μ slots/subframe. The subcarrier spacing and symbol length/duration are a function of the numerology. The subcarrier spacing may be equal to 2 ^μ*15 kHz, where μ is the numerology 0 to 4. As such, the numerology μ=0 has a subcarrier spacing of 15 kHz and the numerology μ=4 has a subcarrier spacing of 240 kHz. The symbol length/duration is inversely related to the subcarrier spacing. FIGs. 2A-2D provide an example of slot configuration 0 with 14 symbols per slot and numerology μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a set of frames, there may be one or more different bandwidth parts (BWPs) (see FIG. 2B) that are frequency division multiplexed. Each BWP may have a particular numerology.

A resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs) ) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs) . The number of bits carried by each RE depends on the modulation scheme.

As illustrated in FIG. 2A, some of the REs carry reference (pilot) signals (RS) for the UE.The RS may include demodulation RS (DM-RS) (indicated as R _x for one particular configuration, where 100x is the port number, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS) , beam refinement RS (BRRS) , and phase tracking RS (PT-RS) .

FIG. 2B illustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) , each CCE including nine RE groups (REGs) , each REG including four consecutive REs in an OFDM symbol. A PDCCH within one BWP may be referred to as a control resource set (CORESET) . Additional BWPs may be located at greater and/or lower frequencies across the channel bandwidth. A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE 104 to determine subframe/symbol timing and a physical layer identity. A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI) . Based on the PCI, the UE can determine the locations of the aforementioned DM-RS. The physical broadcast channel (PBCH) , which carries a master information block (MIB) , may be logically grouped with the PSS and SSS to form a synchronization signal (SS) /PBCH block (also referred to as SS block (SSB) ) . The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN) . The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs) , and paging messages.

As illustrated in FIG. 2C, some of the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH) . The PUSCH DM-RS may be transmitted in the first one or two symbols of the PUSCH. The PUCCH DM-RS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. The UE may transmit sounding reference signals (SRS) . The SRS may be transmitted in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

FIG. 2D illustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI) , such as scheduling requests, a channel quality indicator (CQI) , a precoding matrix indicator (PMI) , a rank indicator (RI) , and hybrid automatic repeat request (HARQ) ACK/NACK feedback. The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR) , a power headroom report (PHR) , and/or UCI.

FIG. 3 is a block diagram of a base station 310 in communication with a UE 350 in an access network. In the DL, IP packets from the EPC 160 may be provided to a controller/processor 375. The controller/processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor 375 provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs) , RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release) , inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression /decompression, security (ciphering, deciphering, integrity protection, integrity verification) , and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs) , error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs) , re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs) , demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor 316 handles mapping to signal constellations 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 coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX may modulate an RF carrier with a respective spatial stream for transmission.

At the UE 350, each receiver 354RX receives a signal through its respective antenna 352. Each receiver 354RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 may perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they may be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT) . The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 310. These soft decisions may be based on channel estimates computed by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station 310 on the physical channel. The data and control signals are then provided to the controller/processor 359, which implements layer 3 and layer 2 functionality.

The controller/processor 359 can be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller/processor 359 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller/processor 359 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

Similar to the functionality described in connection with the DL transmission by the base station 310, the controller/processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression /decompression, and security (ciphering, deciphering, integrity protection, integrity verification) ; RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

Channel estimates derived by a channel estimator 358 from a reference signal or feedback transmitted by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antenna 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a respective spatial stream for transmission.

The UL transmission is processed at the base station 310 in a manner similar to that described in connection with the receiver function at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.

The controller/processor 375 can be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller/processor 375 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 350. IP packets from the controller/processor 375 may be provided to the EPC 160. The controller/processor 375 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

At least one of the TX processor 368, the RX processor 356, and the controller/processor 359 may be configured to perform aspects in connection with 198 of FIG. 1.

At least one of the TX processor 316, the RX processor 370, and the controller/processor 375 may be configured to perform aspects in connection with 198 of FIG. 1.

UEs may be configured to support various network services, such as but not limited to SA or NSA mode. Subscriber identity module (SIM) cards may indicate the subscribed network services of a UE. UEs that support both SA and NSA mode may be configured to attempt to connect with a network via an SA registration prior to attempting to connect with a network via an NSA registration (e.g., LTE attach) . In some instances, the network may not accept an SA registration request from a UE with a SIM card that indicates that the UE only subscribes to NSA mode. In such instances, the UE would not register with the network, and the UE may search for another network (e.g., PLMN or TA) such that the new network may trigger a service request. Such service request may lead the UE to attempt registration with the new network via an SA registration, which will result in the UE failing to connect to the new network due to the new network not accepting an SA registration request from a UE that only subscribes to NSA mode. As a result, the UE may enter an endless service request loop, preventing the UE from obtaining service as well as wasting power.

Aspects presented herein improve the manner in which UEs perform network registration procedures, in instances where a UE does not subscribe to all or most available network services, e.g., in instances where a UE only subscribes to NSA mode and not to SA mode. For example, the UE may be configured to disable SA mode for a certain period of time (e.g., T_Period) when SA registration has failed. Networks may not respond to an SA registration request from UEs that do not subscribe to SA mode. As such, it is desirable for a UE to be configured to disable SA mode when SA registration has failed after a certain amount of times (e.g., MAX_Time) . The certain amount of times (e.g., MAX_Time) that SA registration may fail may be configurable, for example, 5 times. However, the certain amount of times (e.g., MAX_Time) that SA registration may fail may be configured to be less than or greater than 5 times. The UE may also be configured to generate a list of networks that cannot provide SA service registration for UEs that only subscribe to NSA services. At least one advantage of the disclosure is that the UE may avoid further SA registration attempts, while providing for the UE to connect to a network that supports UEs that only subscribe to NSA services.

FIG. 4 is a call flow diagram of signaling between a UE 402, a first network 404, and a second network 406. The first and

second networks

404, 406 may be configured to provide a cell. The UE 402 may be configured to communicate with the first or

second networks

404, 406. For example, in the context of FIG. 1, the first or

second networks

404, 406 may correspond to base station 102/180 and, accordingly, the cell may include a geographic coverage area 110 in which communication coverage is provided and/or small cell 102’ having a coverage area 110’. Further, a UE 402 may correspond to at least UE 104. In another example, in the context of FIG. 3, the first or

second networks

404, 406 may correspond to base station 310 and the UE 402 may correspond to UE 350. Optional aspects are illustrated with a dashed line.

As illustrated at 408, the UE 402 may send a first registration request to the first network 404. The first registration request may indicate one or more network services subscribed to by the UE 402. In some aspects, the first registration request may indicate that the UE 402 may subscribe to an SA service. In some aspects, the first registration request may be for a SA registration to the first network. In some aspects, the UE 402 may be configured to support both NSA mode and SA mode, but the SIM card associated with the UE 402 may only subscribe to NSA service.

As illustrated at 410, the UE 402 may determine whether a first registration response is received from the first network 404. The UE 402 may determine whether the first registration response is received from the first network 404 with a first timer. The first registration request may be considered as a failed request when the first registration response is not received from the first network 404 prior to the expiration of the first timer. The first registration request may be considered a successful request when the first registration response is received from the first network 404 prior to the expiration of the first timer.

In some aspects, as illustrated at 412, the UE 402 may re-send the first registration request to the first network 404 based on the determination that a first registration response has was not received from the first network 404 prior to the expiration of the first timer. In some aspects, the first registration request may be re-sent to the first network 404 a preconfigured number of times. In some aspects, the preconfigured number of times that the first registration request may be re-sent to the first network 404 may comprise five times. The disclosure is not intended to be limited to the aspects disclosed herein. For example, the preconfigured number of times that the first registration request may be re-sent to the first network 404 may be less than five times or greater than five times.

As illustrated at 414, the UE 402 may start a second timer in response to not receiving the first registration response from the first network 404. The UE 402 may start the second timer in response to not receiving the first registration response from the first network prior to the expiration of the first timer. At least one network service of the UE 402 may be disabled for at least a portion of a duration of the second timer. In some aspects, the at least one network service that may be disabled during at least the portion of the duration of the second timer may comprise an SA service. In some aspects, the UE 402 may start the second timer when the first registration request has been re-sent for the preconfigured number of times. In some aspects, the UE 402 may start the second timer when the re-sent first registration request has failed for each of the preconfigured number of times that the first registration request has been re-sent to the first network. In some aspects, the SA service may be disabled for the duration of the second timer if the SA registration request has failed. Disabling the SA service may allow the UE 402 to avoid further SA registration failures, which may provide a power savings. In some aspects, the second timer may comprise a duration of 24 hours. However, in some aspects, the second timer may be configurable and may comprise a duration that is less than or greater than 24 hours. In some aspects, the at least one network service that is disabled during the second timer may be enabled upon the expiration of the second timer. In some aspects, the at least one network service that is disabled during the second timer may be enabled in the event that the UE experiences a power cycle, such that the UE is powered off and then powered on.

In some aspects, as illustrated at 416, the UE 402 may generate a list of networks (e.g., public land mobile networks (PLMNs) ) that do not provide SA service. The list of networks (e.g., PLMNs) on the list are blocked by the UE 402 for at least the portion of the duration of the second timer. For example, the UE 402 may add the first network 404 to the list when the UE 402 does not receive the first registration response from the first network 404 in response to the UE 402 sending the first registration request. In some aspects, the UE 402 may add the first network 404 (or other networks that do not send a registration response to the UE 402) to the list after the first registration request has been re-sent the preconfigured number of times to the first network 404 (or other networks) . Adding the first network 404 (or other networks) to the list allows the UE 402 to avoid sending registration requests (e.g., first registration request) to the first network 404 (or other networks) that do not support the subscribed services (e.g., NSA mode only) of the UE 402.

As illustrated at 418, the UE 402 may send a second registration request to a second network 406. In some aspects, the second registration request may comprise an attach request for the second network 406. The second network 406 may support the subscribed services (e.g., SA mode) of the UE 402. The second network 406 may also support NSA mode. In some aspects, the second registration request may comprise an attach request (e.g., LTE ATTACH) for the second network 406. In some aspects, the UE 402 may send the second registration request comprising an attached request (e.g., LTE ATTACH) if the first network 404 does not support SA mode for the UE 402, and the UE 402 is unable to locate another network (e.g., PLMN) that supports SA, such that the second registration request sent to the second network 406 is for NSA mode.

As illustrated at 420, the second network 406 may send a second registration response to the UE 402, in response to receiving the second registration request from the UE 402. The second registration response may comprise an acceptance of the attach request sent by the UE 402. The UE 402 may receive the second registration response from the second network 406. The UE 402 may receive the second registration response from the second network 406 in response to sending the second registration request. The UE 402 may then camp onto a cell provided by the second network 406 and communicate with the second network 406.

FIG. 5 is a flowchart 500 of a method of wireless communication. The method may be performed by a UE or a component of a UE (e.g., the

UE

104, 350, 402; the apparatus 602; the cellular baseband processor 604, which may include the memory 360 and which may be the entire UE 350 or a component of the UE 350, such as the TX processor 368, the RX processor 356, and/or the controller/processor 359) . One or more of the illustrated operations may be omitted, transposed, or contemporaneous. Optional aspects are illustrated with a dashed line. The method may allow a UE to disable SA mode for a period of time when SA registration has failed in order to avoid additional SA service request failures.

At 502, the UE may send a first registration request to a first network. For example, 502 may be performed by transmission component 634 of apparatus 602. The first registration request may indicate one or more network services subscribed to by the UE. In some aspects, the first registration request may indicate that the UE may subscribe to an SA service. In some aspects, the first registration request may be for an SA registration to the first network.

At 504, the UE may determine whether a first registration response is received from the first network. For example, 504 may be performed by determination component 640 of apparatus 602. The UE may determine whether the first registration response is received from the first network with a first timer. The first registration request may be considered as a failed request when the first registration response is not received from the first network prior to the expiration of the first timer. The first registration request may be considered a successful request when the first registration response is received from the first network prior to the expiration of the first timer.

In some aspects, for example at 506, the UE may re-send the first registration request to the first network. For example, 506 may be performed by transmission component 634 of apparatus 602. The UE may re-send the first registration request to the first network based on the determination that the first registration response was not received from the first network prior to the expiration of the first timer. In some aspects, the first registration request may be re-sent to the first network a preconfigured number of times. In some aspects, the preconfigured number of times that the first registration request may be re-sent to the first network may comprise five times. The disclosure is not intended to be limited to the aspects disclosed herein. For example, the preconfigured number of times that the first registration request may be re-sent to the first network may be less than five times or greater than five times.

At 508, the UE may start a second timer in response to not receiving the first registration response from the first network. For example, 508 may be performed by timer component 642 of apparatus 602. The UE may start the second timer in response to not receiving the first registration response from the first network prior to the expiration of the first timer. At least one network service of the UE may be disabled for at least a portion of a duration of the second timer. In some aspects, the at least one network service that may be disabled during at least the portion of the duration of the second timer comprises an SA service. In some aspects, the UE may start the second timer when the re-sent first registration request has been re-sent for the preconfigured number of times. In some aspects, the UE may start the second timer when the re-sent first registration request has failed for each of the preconfigured number of times that the first registration request has been re-sent to the first network.

In some aspects, for example at 510, the UE may generate a list of networks (e.g., PLMNs) that do not provide SA service. For example, 510 may be performed by list component 644 of apparatus 602. The list of networks (e.g., PLMNs) on the list are blocked by the UE for at least the portion of the duration of the second timer. For example, the UE may add the first network to the list when the UE does not receive a first registration response from the first network in response to the UE sending the first registration request. In some aspects, the UE may add the first network (or other networks that do not send a registration response to the UE) to the list after the first registration request has been re-sent the preconfigured number of times to the first network (or other networks) .

At 512, the UE may send a second registration request. For example, 512 may be performed by transmission component 634 of apparatus 602. The UE may send the second registration request to a second network. In some aspects, the second registration request may comprise an attach request for the second network.

At 514, the UE may receive a second registration response. For example, 514 may be performed by reception component 630 of apparatus 602. The UE may receive the second registration response from the second network. The UE may receive the second registration response from the second network in response to sending the second registration request. In some aspects, the second registration response from the second network may comprise an acceptance of the attach request.

FIG. 6 is a diagram 600 illustrating an example of a hardware implementation for an apparatus 602. The apparatus 602 is a UE and includes a cellular baseband processor 604 (also referred to as a modem) coupled to a cellular RF transceiver 622 and one or more subscriber identity modules (SIM) cards 620, an application processor 606 coupled to a secure digital (SD) card 608 and a screen 610, a Bluetooth module 612, a wireless local area network (WLAN) module 614, a Global Positioning System (GPS) module 616, and a power supply 618. The cellular baseband processor 604 communicates through the cellular RF transceiver 622 with the UE 104 and/or BS 102/180. The cellular baseband processor 604 may include a computer-readable medium /memory. The computer-readable medium /memory may be non-transitory. The cellular baseband processor 604 is responsible for general processing, including the execution of software stored on the computer-readable medium /memory. The software, when executed by the cellular baseband processor 604, causes the cellular baseband processor 604 to perform the various functions described supra. The computer-readable medium /memory may also be used for storing data that is manipulated by the cellular baseband processor 604 when executing software. The cellular baseband processor 604 further includes a reception component 630, a communication manager 632, and a transmission component 634. The communication manager 632 includes the one or more illustrated components. The components within the communication manager 632 may be stored in the computer-readable medium /memory and/or configured as hardware within the cellular baseband processor 604. The cellular baseband processor 604 may be a component of the UE 350 and may include the memory 360 and/or at least one of the TX processor 368, the RX processor 356, and the controller/processor 359. In one configuration, the apparatus 602 may be a modem chip and include just the baseband processor 604, and in another configuration, the apparatus 602 may be the entire UE (e.g., see 350 of FIG. 3) and include the aforediscussed additional modules of the apparatus 602.

The communication manager 632 includes a determination component 640 that is configured to determine whether a first registration response is received from the first network, e.g., as described in connection with 504 of FIG. 5. The communication manager 632 further includes a timer component 642 that is configured to start a second timer in response to not receiving the first registration response from the first network, e.g., as described in connection with 508 of FIG. 5. The communication manager 632 further includes a list component 644 that is configured to generate a list of networks (e.g., public land mobile networks (PLMNs) ) that do not provide SA service, e.g., as described in connection with 510 of FIG. 5. The transmission component 634 is configured to send a first registration request to a first network, e.g., as described in connection with 502 of FIG. 5. The transmission component 634 is configured to re-send the first registration request to the first network, e.g., as described in connection with 506 of FIG. 5. The transmission component 634 is configured to send a second registration request to a second network, e.g., as described in connection with 512 of FIG. 5. The reception component 630 is configured to receive a second registration response from the second network, e.g., as described in connection with 514 of FIG. 5.

The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowchart of FIG. 5. As such, each block in the aforementioned flowchart of FIG. 5 may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

In one configuration, the apparatus 602, and in particular the cellular baseband processor 604, includes means for sending a first registration request to a first network. The first registration request indicates one or more network services subscribed to by the UE. The apparatus includes means for determining whether a first registration response is received from the first network within a first timer. The first registration request has failed when the first registration response from the first network is not received prior to the expiration of the first timer. The apparatus includes means for starting a second timer in response to the UE not receiving the first registration response from the first network prior to the expiration of the first timer. At least one network service of the UE is disabled for at least a portion of a duration of the second timer. The apparatus includes means for sending a second registration request to a second network. The apparatus includes means for receiving a second registration response from the second network. The apparatus further includes means for re-sending the first registration request to the first network upon the expiration of the first timer. The first registration request is re-sent a preconfigured number of times. The apparatus further includes means for generating a list of PLMNs that do not provide SA service. The PLMNs on the list are blocked by the UE for at least the portion of the duration of the second timer. The aforementioned means may be one or more of the aforementioned components of the apparatus 602 configured to perform the functions recited by the aforementioned means. As described supra, the apparatus 602 may include the TX Processor 368, the RX Processor 356, and the controller/processor 359. As such, in one configuration, the aforementioned means may be the TX Processor 368, the RX Processor 356, and the controller/processor 359 configured to perform the functions recited by the aforementioned means.

It is understood that the specific order or hierarchy of blocks in the processes /flowcharts disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes /flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

The following examples are illustrative only and may be combined with aspects of other embodiments or teachings described herein, without limitation.

Example 1 is a method of wireless communication at a UE comprising sending a first registration request to a first network, wherein the first registration request indicates one or more network services subscribed to by the UE; determining whether a first registration response is received from the first network within a first timer, wherein the first registration request has failed when the first registration response from the first network is not received prior to the expiration of the first timer; starting a second timer in response to the UE not receiving the first registration response from the first network prior to the expiration of the first timer, wherein at least one network service of the UE is disabled for at least a portion of a duration of the second timer; sending a second registration request to a second network; and receiving a second registration response from the second network.

In Example 2, the method of Example 1 further includes that the first registration request indicates that the UE subscribes to an SA service, and wherein the first registration request is for an SA registration to the first network.

In Example 3, the method of Example 1 or 2 further includes that the at least one network service disabled during at least the portion of the duration of the second timer comprises a SA service.

In Example 4, the method of any of Examples 1-3 further includes re-sending the first registration request to the first network upon the expiration of the first timer, wherein the first registration request is re-sent a preconfigured number of times.

In Example 5, the method of any of Examples 1-4 further includes that the second timer is started when the re-sent first registration request has failed the preconfigured number of times.

In Example 6, the method of any of Examples 1-5 further includes generating a list of PLMNs that do not provide SA service, wherein PLMNs on the list are blocked by the UE for at least the portion of the duration of the second timer.

In Example 7, the method of any of Examples 1-6 further includes that the second registration request is an attach request for the second network.

In Example 8, the method of any of Examples 1-7 further includes that the second registration response from the second network is an acceptance of the attach request.

Example 9 is a device including one or more processors and one or more memories in electronic communication with the one or more processors storing instructions executable by the one or more processors to cause the system or apparatus to implement a method as in any of Examples 1-8.

Example 10 is a system or apparatus including means for implementing a method or realizing an apparatus as in any of Examples 1-8.

Example 11 is a non-transitory computer readable medium storing instructions executable by one or more processors to cause the one or more processors to implement a method as in any of Examples 1-8.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more. ” Terms such as “if, ” “when, ” and “while” should be interpreted to mean “under the condition that” rather than imply an immediate temporal relationship or reaction. That is, these phrases, e.g., “when, ” do not imply an immediate action in response to or during the occurrence of an action, but simply imply that if a condition is met then an action will occur, but without requiring a specific or immediate time constraint for the action to occur. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration. ” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module, ” “mechanism, ” “element, ” “device, ” and the like may not be a substitute for the word “means. ” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for. ”

Claims

A method of wireless communication at a user equipment (UE) , comprising:

sending a first registration request to a first network, wherein the first registration request indicates one or more network services subscribed to by the UE;

determining whether a first registration response is received from the first network within a first timer, wherein the first registration request has failed when the first registration response from the first network is not received prior to the expiration of the first timer;

starting a second timer in response to the UE not receiving the first registration response from the first network prior to the expiration of the first timer, wherein at least one network service of the UE is disabled for at least a portion of a duration of the second timer;

sending a second registration request to a second network; and

receiving a second registration response from the second network.
The method of claim 1, wherein the first registration request indicates that the UE subscribes to a standalone (SA) service, and wherein the first registration request is for an SA registration to the first network.
The method of claim 1, wherein the at least one network service disabled during at least the portion of the duration of the second timer comprises a standalone (SA) service.
The method of claim 1, further comprising:

re-sending the first registration request to the first network upon the expiration of the first timer, wherein the first registration request is re-sent a preconfigured number of times.
The method of claim 4, wherein the second timer is started when the re-sent first registration request has failed the preconfigured number of times.
The method of claim 1, further comprising:

generating a list of public land mobile networks (PLMNs) that do not provide standalone (SA) service, wherein PLMNs on the list are blocked by the UE for at least the portion of the duration of the second timer.
The method of claim 1, wherein the second registration request is an attach request for the second network.
The method of claim 7, wherein the second registration response from the second network is an acceptance of the attach request.
An apparatus for wireless communication at a user equipment (UE) , comprising:

a memory; and

at least one processor coupled to the memory and configured to:

send a first registration request to a first network, wherein the first registration request indicates one or more network services subscribed to by the UE;

determine whether a first registration response is received from the first network within a first timer, wherein the first registration request has failed when the first registration response from the first network is not received prior to the expiration of the first timer;

start a second timer in response to the UE not receiving the first registration response from the first network prior to the expiration of the first timer, wherein at least one network service of the UE is disabled for at least a portion of a duration of the second timer;

send a second registration request to a second network; and

receive a second registration response from the second network.
The apparatus of claim 9, wherein the first registration request indicates that the UE subscribes to a standalone (SA) service, and wherein the first registration request is for an SA registration to the first network.
The apparatus of claim 9, wherein the at least one network service disabled during at least the portion of the duration of the second timer comprises a standalone (SA) service.
The apparatus of claim 9, wherein that at least one processor configured to:

re-send the first registration request to the first network upon the expiration of the first timer, wherein the first registration request is re-sent a preconfigured number of times.
The apparatus of claim 12, wherein the second timer is started when the re-sent first registration request has failed the preconfigured number of times.
The apparatus of claim 9, wherein that at least one processor configured to:

generate a list of public land mobile networks (PLMNs) that do not provide standalone (SA) service, wherein PLMNs on the list are blocked by the UE for at least the portion of the duration of the second timer.
The apparatus of claim 9, wherein the second registration request is an attach request for the second network.
The apparatus of claim 15, wherein the second registration response from the second network is an acceptance of the attach request.
An apparatus for wireless communication at a user equipment (UE) , comprising:

means for sending a first registration request to a first network, wherein the first registration request indicates one or more network services subscribed to by the UE;

means for determining whether a first registration response is received from the first network within a first timer, wherein the first registration request has failed when the first registration response from the first network is not received prior to the expiration of the first timer;

means for starting a second timer in response to the UE not receiving the first registration response from the first network prior to the expiration of the first timer, wherein at least one network service of the UE is disabled for at least a portion of a duration of the second timer;

means for sending a second registration request to a second network; and

means for receiving a second registration response from the second network.
The apparatus of claim 17, wherein the first registration request indicates that the UE subscribes to a standalone (SA) service, and wherein the first registration request is for an SA registration to the first network.
The apparatus of claim 17, wherein the at least one network service disabled during at least the portion of the duration of the second timer comprises a standalone (SA) service.
The apparatus of claim 17, further comprising:

means for re-sending the first registration request to the first network upon the expiration of the first timer, wherein the first registration request is re-sent a preconfigured number of times.
The apparatus of claim 20, wherein the second timer is started when the re-sent first registration request has failed the preconfigured number of times.
The apparatus of claim 17, further comprising:

means for generating a list of public land mobile networks (PLMNs) that do not provide standalone (SA) service, wherein PLMNs on the list are blocked by the UE for at least the portion of the duration of the second timer.
The apparatus of claim 17, wherein the second registration request is an attach request for the second network.
The apparatus of claim 23, wherein the second registration response from the second network is an acceptance of the attach request.
A computer-readable medium storing computer executable code, the code when executed by a processor cause the processor to:

send a first registration request to a first network, wherein the first registration request indicates one or more network services subscribed to by the UE;

determine whether a first registration response is received from the first network within a first timer, wherein the first registration request has failed when the first registration response from the first network is not received prior to the expiration of the first timer;

start a second timer in response to the UE not receiving the first registration response from the first network prior to the expiration of the first timer, wherein at least one network service of the UE is disabled for at least a portion of a duration of the second timer;

send a second registration request to a second network; and

receive a second registration response from the second network.