UE specific method for nr / lte / 3g / 2g call performance improvement during irat reselection procedure

Abstract

The present disclosure relates to UE specific methods for NR / LTE / 3G / 2G call performance improvement during IRAT reselection procedure. Methods, apparatuses, and systems for reducing latency during IRAT reselection in the presence of race conditions are disclosed. When a UE initiates an IRAT reselection procedure and simultaneously initiates a call setup procedure, a race condition can result in which the NAS layer of the UE prioritizes the call setup procedure while the RRC layer prioritizes the IRAT reselection procedure. This can result in a failure of the call setup procedure, which can result in the user needing to reinitiate the call, resulting in a poor user experience and significant latency. To prevent this, the UE can cache messages and / or other information related to the call setup procedure until the IRAT reselection procedure is complete. The UE can then continue to complete the call setup procedure. The messages can be cached, for example, at the NAS layer or the RRC layer of the cellular modem or by an application processor.

Description

TECHNICAL FIELD

[0001] This application relates to wireless communications, and more specifically to systems, apparatus and methods for reducing latency during IRAT reselection in a wireless communication system.

[0002] Related Art

[0003] The use of wireless communication systems is expanding rapidly. In recent years, wireless devices such as smart phones and tablet computers have become increasingly sophisticated. In addition to supporting telephone calls, many mobile devices (i.e., user equipment devices or UEs) now provide access to the Internet, email, text messaging, and navigation using the global positioning system (GPS), and can operate sophisticated, complex applications that utilize these functions. Additionally, there are numerous different wireless communication technologies and wireless communication standards. Some examples of wireless communication standards include GSM, UMTS (e.g., associated with the WCDMA or TD-SCDMA air interfaces), LTE, LTE-Advanced (LTE-A), NR, HSPA, 3GPP2 CDMA2000 (e.g., lxRTT, lxEV-DO, HRPD, eHRPD), IEEE 802.11 (WLAN or Wi-Fi), BLUETOOTH TM and others.

[0004] The introduction of an ever-increasing number of features and functions in wireless communication devices also creates an ongoing need for improvements in wireless communication and improvements in wireless communication devices. In particular, it is important to ensure an acceptable user experience when utilizing user equipment (UE) devices such as cellular telephones and smart devices. Thus, improvements in this area are desirable. SUMMARY

[0005] Embodiments of apparatuses, systems, and methods for reducing latency during inter radio access technology (IRAT) reselection in a wireless communication system in the presence of race conditions are presented herein.

[0006] For example, a method for expediting call setup is described. The method can be performed by a cellular modem of a user equipment (UE) device. The cellular modem can initiate an inter radio access technology (IRAT) reselection procedure, and while the IRAT reselection procedure is pending, the cellular modem can also receive a request to initiate a call setup procedure. In response to determining that the IRAT reselection procedure is pending, the cellular modem can suspend processing of the call setup procedure. The cellular modem can then complete the IRAT reselection procedure. In response to determining that the IRAT reselection procedure is complete, the cellular modem can resume processing of the call setup procedure.

[0007] In some scenarios, the processing to suspend the call setup procedure can include a radio resource control (RRC) layer of the cellular modem to cache a request to resume the suspended call connection. In some scenarios, the processing to suspend the call setup procedure can include the RRC layer of the cellular modem to cache a request to establish a new call connection.

[0008] In some scenarios, the processing to suspend the call setup procedure can include a non-access stratum (NAS) layer of the cellular modem to cache a call setup request message.

[0009] In some scenarios, completing the IRAT reselection procedure can include failing to switch to the new cell. In some scenarios, completing the IRAT reselection procedure can include camping on the new cell.

[0010] In some scenarios, the processing to resume the call setup procedure can include establishing a call on the new cell.

[0011] As another example, another method for expediting call setup is described that is performed by a processor of a user equipment (UE) device. The processor can provide a first request to initiate a call setup procedure to a cellular modem of the UE device. The processor can receive an indication from the cellular modem that the call setup procedure failed because the cellular modem is currently performing an inter radio access technology (IRAT) reselection procedure. In response to the indication of the call setup procedure failure, the processor can store call context information about the requested call setup procedure. In response to an indication from the cellular modem that the IRAT reselection procedure is complete, the processor can provide a second request to initiate the call setup procedure to the cellular modem based on the stored call context information.

[0012] In some scenarios, the processor can receive an initial request from a user interface component of the UE device to initiate the call setup procedure, where the first request is in response to the initial request, and where the second request is provided without additional input from the user interface component.

[0013] Apparatuses, systems, and non-transitory memory media used to implement these and other methods are described.

[0014] A UE device is described that includes at least one processor and a cellular modem communicatively coupled to the at least one processor. The cellular modem can be configured to initiate an inter radio access technology (IRAT) reselection procedure. While the IRAT reselection procedure is pending, the cellular modem can receive a request from the at least one processor to initiate a call setup procedure. In response to determining that the IRAT reselection procedure is pending, the cellular modem can suspend processing of the call setup procedure. The cellular modem can then complete the IRAT reselection procedure. In response to determining that the IRAT reselection procedure is complete, the cellular modem can resume processing of the call setup procedure.

[0015] In some scenarios, suspending processing of the call setup procedure can include a radio resource control (RRC) module of the cellular modem storing a request to resume a suspended call connection. In some scenarios, suspending processing of the call setup procedure can include a radio resource control (RRC) module of the cellular modem storing a request to establish a new call connection. In some scenarios, suspending processing of the call setup procedure can include a non-access stratum (NAS) module of the cellular modem storing a call setup request message.

[0016] In some scenarios, completing the IRAT reselection procedure can include failing to handover to a new cell. In some scenarios, completing the IRAT reselection procedure can include camping on a new cell.

[0017] In some scenarios, resuming processing of the call setup procedure can include establishing a call on the new cell.

[0018] A cellular modem is described that can include a non-access stratum (NAS) module and a radio resource control (RRC) module. The RRC module can be configured to store a request message from the NAS module in response to determining that the request message was received during a pending inter radio access technology (IRAT) reselection procedure. The RRC module can then process the request message in response to determining that the IRAT reselection procedure has completed. The request message can include one of a request to establish a call connection or a request to resume a call connection. Processing the requested message can include attempting to establish or resume the call connection.

[0019] A cellular modem can include a radio resource control (RRC) module and a non-access stratum (NAS) module. The NAS module can be configured to receive a call setup request and provide a first call connection request message to the RRC module based on the call setup request. The first call connection request message can include a request to establish or resume a call connection. The cellular modem can receive a rejection message from the RRC module indicating that the request to establish or resume a call connection is rejected because the cellular modem is performing an inter radio access technology (IRAT) reselection procedure. In response to receiving the rejection message, the cellular modem can store the call setup request. The cellular modem can then receive an indication from the RRC module that the IRAT reselection procedure is complete. In response to the indication that the IRAT reselection procedure is complete, the cellular modem can provide a second call connection request message to the RRC module based on the stored call setup request, the second call connection request message including the request to establish or resume a call connection.

[0020] It should be noted that the techniques described herein can be implemented in and / or used with a number of different types of devices, including, but not limited to, base stations, access points, mobile phones, tablet computers, wearable devices, unmanned aerial vehicles, unmanned aerial vehicle controllers, automobiles and / or motor vehicles, and various other computing devices.

[0021] This Summary is intended to provide a brief overview of some of the subject matter described in this document. Accordingly, it will be appreciated that the above-described features are merely examples and should not be construed to narrow the scope or spirit of the subject matter as described herein. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following DETAILED DESCRIPTION, Figures, and Claims. BRIEF DESCRIPTION OF DRAWINGS

[0022] A better understanding of the present subject matter can be obtained when the following detailed description of various embodiments is considered in conjunction with the following drawings, in which:

[0023] Figure 1 An exemplary (and simplified) wireless communication system according to some embodiments is illustrated;

[0024] Figure 2 An exemplary base station in communication with exemplary wireless user equipment (UE) devices according to some embodiments is illustrated;

[0025] Figure 3 An exemplary block diagram of a UE according to some embodiments is illustrated;

[0026] Figure 4An exemplary block diagram of a base station is shown in accordance with some embodiments;

[0027] Figures 5A-5B A signal flow diagram showing an example of presenting a race condition between call setup and IRAT reselection in accordance with the prior art, which results in a significant delay observed by the user;

[0028] Figures 6A-6C A signal flow diagram showing an example scenario in which the NRRC can cache the resume request message during IRAT reselection in accordance with some embodiments;

[0029] Figures 7A-7B A signal flow diagram showing an example scenario in which the AP can cache the call context information during IRAT reselection in accordance with some embodiments;

[0030] Figures 8A-8B A signal flow diagram showing an example scenario in which the NAS can cache the call setup message during IRAT reselection in accordance with some embodiments;

[0031] Figure 9 is a flow diagram showing a method performed by a cellular modem for reducing delay during IRAT reselection in the presence of a race condition in accordance with some embodiments; and

[0032] Figure 10 is a flow diagram showing a method performed by an application processor for reducing delay during IRAT reselection in the presence of a race condition in accordance with some embodiments.

[0033] While features described herein are susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the disclosure to the particular form disclosed but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the subject matter defined by the appended claims. DETAILED DESCRIPTION

[0034] Acronyms

[0035] Various acronyms are used throughout this disclosure. Definitions of the most prominent acronyms used throughout this disclosure are as follows:

[0036] • UE: User Equipment

[0037] • RF: Radio Frequency

[0038] • GSM: Global System for Mobile Communications

[0039] UMTS: Universal Mobile Telecommunications System

[0040] EUTRA: Evolved UMTS Terrestrial Radio Access

[0041] LTE: Long Term Evolution

[0042] NR: New Radio

[0043] TX: Transmission

[0044] RX: Receiver

[0045] • RAT: Radio Access Technology

[0046] •IRAT: Radio Access Technology

[0047] AP: Application Processor

[0048] NAS: Non-Access Layer

[0049] •RRC: Radio Resource Control

[0050] NW: Network

[0051] Terminology

[0052] The following is a glossary of terms that will appear in this disclosure:

[0053] Memory media—any device of any type of nontransitory memory device or storage device. The term "memory media" is intended to include mounting media such as CD-ROMs, floppy disks, or magnetic tape devices; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory such as flash memory, magnetic media, e.g., hard disk drives or optical storage devices; registers or other similar types of memory elements, etc. Memory media may also include other types of nontransitory memory or combinations thereof. Furthermore, memory media may reside in a first computer system executing a program, or may reside in a different second computer system connected to the first computer system via a network such as the Internet. In a later example, the second computer system may provide program instructions to the first computer system for execution. The term "memory media" may include two or more memory media that may reside in different locations on different computer systems connected via a network, for example. Memory media may store program instructions (e.g., representing a computer program) that can be executed by one or more processors.

[0054] Carrier medium—the memory medium as described above, and physical transmission medium, such as buses, networks, and / or other physical transmission media for transmitting signals (such as electrical signals, electromagnetic signals, or digital signals).

[0055] Computer system (or computer) — any of the various types of computing or processing systems, including personal computer systems (PCs), mainframe computer systems, workstations, network appliances, internet-connected appliances, personal digital assistants (PDAs), television systems, grid computing systems, or other devices or combinations thereof. Generally, the term "computer system" can be broadly defined as any device (or combination of devices) that includes at least one processor that executes instructions from a memory medium.

[0056] User equipment (UE) (or “UE device”) — any of various types of computer systems or devices that are mobile or portable and perform wireless communications. Examples of UE devices include mobile phones or smartphones (e.g., iPhone). TM Based on Android TM Phones), tablets (e.g., iPads) TM Samsung Galaxy TM ), portable gaming devices (e.g., Nintendo DS) TM PlayStation Portable TM Gameboy Advance TM iPhone TM This includes wearable devices (e.g., smartwatches, smart glasses), laptops, PDAs, portable internet devices, music players, data storage devices, other handheld devices, automobiles and / or motor vehicles, unmanned aerial vehicles (UAVs) (e.g., drones), UAV controllers (UACs), etc. Generally speaking, the term "UE" or "UE device" can be broadly defined to encompass any electronic device, computing device, and / or telecommunications device (or a combination of these devices) that is easily transportable by the user and capable of wireless communication.

[0057] A wireless device is any of various types of computer systems or devices that perform wireless communication. A wireless device can be portable (or mobile), or it can be stationary or fixed in a location. A UE is an example of a wireless device.

[0058] A communication device is any of various types of computer systems or devices that perform communication, which may be wired or wireless. A communication device may be portable (or mobile), or it may be stationary or fixed in a location. A wireless device is one example of a communication device. A UE is another example of a communication device.

[0059] Base Station (BS) - the term "base station" has the full breadth of its ordinary meaning and at least includes a wireless communication station installed at a fixed location and used to communicate as part of a wireless telephone system or radio system.

[0060] Processing Element (or Processor) - refers to various elements or combinations of elements that are capable of performing a function of a device such as a user equipment device or a cellular network device. Processing elements can include, for example, processors and associated memory, portions or circuits of processors or processor cores, entire processors or processor cores, processor arrays, circuits such as an ASIC (Application Specific Integrated Circuit), programmable hardware elements such as a field programmable gate array (FPGA), any of various combinations thereof, and the like.

[0061] Wi-Fi - the term "Wi-Fi" has the full breadth of its ordinary meaning and at least includes a wireless communication network or RAT that provides services using wireless LAN (WLAN) access points and that provides connectivity to the Internet through these access points. Most modern Wi-Fi networks (or WLAN networks) are based on IEEE 802.11 standards and marketed under the name "Wi-Fi." Wi-Fi (WLAN) networks are distinct from cellular networks.

[0062] Automatically - refers to an action or operation being performed without direct specification or input from a user. For example, the term "automatically" is used herein to mean, for example, that a computer system or device performs an action or action without user intervention, request, or input. The term "automatically" is also used herein to mean, for example, that a computer system or device performs an action or operation without user interaction or input, for example, that the computer system or device performs an action or operation automatically without requiring user intervention, request, or input. The term "automatically" is also used herein to mean, for example, that a computer system or device performs an action or operation automatically after a user has provided input or a request to perform the action or operation. The term "automatically" is also used herein to mean, for example, that a computer system or device performs an action or operation automatically after a user has provided input or a request to perform the action or operation, and that the computer system or device performs the action or operation without requiring user interaction or input.

[0063] Configured To - Various components can be described as being "configured to" perform one or more tasks. In such contexts, "configured to" is a broad recitation of structure generally meaning "having structure that" performs the one or more tasks during operation. As such, a component can be configured to perform one or more tasks even when the component is not currently on or is currently off. In some contexts, "configured to" can be described as being a broad recitation of structure generally meaning "having circuitry that" performs the one or more tasks during operation. As such, a component can be configured to perform one or more tasks even when the component is not currently on or is currently off. Typically, the circuitry that forms the structure corresponding to "configured to" can include hardware circuitry.

[0064] For ease of description, various components can be described as performing one or more tasks. Such descriptions should be interpreted as including the phrase "configured to." A component that is configured to perform one or more tasks is expressly intended to invoke the interpretation of that component not invoking the interpretation of Section 112, Paragraph 6 of the U.S. Code Title 35.

[0065] Figure 1 and Figure 2 - Exemplary communication system

[0066] Figure 1 An example (and simplified) wireless communication system in which aspects of the present disclosure can be implemented is illustrated in accordance with some embodiments. Note that Figure 1 The system of FIG. 1 is merely one example of a possible system, and this embodiment can be implemented in any of various systems as desired.

[0067] As shown, the example wireless communication system includes a base station 102, which communicates over a transmission medium with one or more (e.g., any number) of user devices 106A, 106B, etc., through 106N. Each user device can be referred to herein as a "user equipment" (UE) or UE device. Thus, user device 106 is referred to as a UE or UE device.

[0068] The base stations 102 can be transceiver base stations (BTSs) or cell sites, and can include hardware and / or software that enables wireless communication with the UEs 106A through 106N. If implemented in the context of LTE, the base stations 102 can be referred to as “eNodeBs” or “eNBs.” If implemented in the context of 5G NR, the base stations 102 can alternatively be referred to as “gNodeBs” or “gNBs.” The base stations 102 can also be equipped to communicate with the network 100 (e.g., with a core network of a cellular service provider, with a telecommunications network such as a public switched telephone network (PSTN), and / or with the Internet, among various possible networks). Thus, the base stations 102 can facilitate communications between the user devices and / or between user devices and the network 100. The communication areas (or coverage areas) of the base stations can be referred to as “cells.” Also as used herein, with respect to a UE, a base station can be considered to represent the network in instances where both uplink and downlink communications of the UE are considered with respect to the base station. Thus, a UE in communication with one or more base stations in the network can also be understood to be a UE in communication with the network.

[0069] The base stations 102 and user devices can be configured to communicate over transmission media using any of a variety of radio access technologies (RATs), also referred to as wireless communication technologies or telecommunication standards, such as GSM, UMTS (WCDMA), LTE, LTE-Advanced (LTE-A), LAA / LTE-U, 5G NR, 3GPP2, CDMA2000 (e.g., lxRTT, lxEV-DO, HRPD, eHRPD), Wi-Fi, and so on.

[0070] The base stations 102 and other similar base stations operating according to the same or a different cellular communication standard can thus provide service as one or more cell networks that can provide continuous or approximately continuous overlapping service to UEs 106 and similar devices via one or more cellular communication standards over a certain geographic area.

[0071] Note that the UEs 106 are capable of communicating using multiple wireless communication standards. For example, the UEs 106 can be configured to communicate using either or both of a 3GPP cellular communication standard or a 3GPP2 cellular communication standard. In some embodiments, the UEs 106 can be configured to perform techniques for reducing latency during IRAT reselection in a wireless communication system, such as according to the various methods described herein. The UEs 106 can also be configured to, or as an alternative, use WLAN, BLUETOOTH TMone or more global navigation satellite systems (GNSS, e.g., GPS or GLONASS), one and / or more mobile television broadcasting standards (e.g., ATSC-M / H), etc. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible.

[0072] Figure 2 An exemplary user equipment 106 (e.g., one of devices 106A-106N) in communication with base station 102 in accordance with some embodiments is shown. UE 106 can be a device with wireless network connectivity such as a mobile phone, a handheld device, a wearable device, a computer or tablet, an unmanned aerial vehicle (UAV), an unmanned aerial controller (UAC), a car, or almost any type of wireless device. UE 106 can include a processor (processing element) configured to execute program instructions stored in memory. The UE 106 can perform any of the method embodiments described herein by executing such stored instructions. Alternatively, or additionally, the UE 106 can include a programmable hardware element such as an FPGA (field programmable gate array), an integrated circuit, and / or any of various other programmable hardware elements, configured to perform any of the method embodiments described herein, or any portion thereof. The UE 106 can be configured to communicate using any of multiple wireless communication protocols. For example, the UE 106 can be configured to communicate using two or more of CDMA2000, LTE, LTE-A, 5G NR, WLAN, or GNSS. Other combinations of wireless communication standards are also possible.

[0073] The UE 106 can include one or more antennas that use one or more wireless communication protocols to communicate in accordance with one or more RAT standards. In some embodiments, the UE 106 can share one or more portions of receive chains and / or transmit chains between multiple wireless communication standards. The shared radio can include a single antenna, or can include multiple antennas for performing wireless communication (e.g., for MIMO). In general, a radio can include any combination of baseband processors, analog radio frequency (RF) signal processing circuitry (e.g., including filters, mixers, oscillators, amplifiers, etc.), or digital processing circuitry (e.g., for digital modulation and other digital processing). Similarly, the radio can implement one or more receive chains and transmit chains using the aforementioned hardware.

[0074] In some embodiments, the UE 106 can include separate transmit and / or receive chains (e.g., including separate antennas and other radio components) for each wireless communication protocol with which it is configured to communicate. As another possibility, the UE 106 can include one or more radio components that are shared among multiple wireless communication protocols, as well as one or more radio components that are used exclusively by a single wireless communication protocol. For example, the UE 106 can include shared radio components for communicating using either of LTE or CDMA2000 lxRTT (or LTE or NR, or LTE or GSM), as well as separate radio components for communicating using each of Wi-Fi and BLUETOOTH®. Other configurations are also possible. TM

[0075] Figure 3 Block diagram of an exemplary UE device

[0076] Figure 3 ​A block diagram illustrating an example UE 106 according to some embodiments is shown. As shown, the UE 106 can include a system on a chip (SOC) 300, which can include portions for various purposes. For example, as shown, the SOC 300 can include a processor 302, which can execute program instructions for the UE 106, and display circuitry 304, which can perform graphics processing and provide display signals to the display 360. In some implementations, the display 360 can include a touch screen capable of detecting user input such as touch events. The SOC 300 can also include sensor circuitry 370, which can include components to sense or measure any of a variety of possible characteristics or parameters of the UE 106. For example, the sensor circuitry 370 can include motion sensing circuitry configured to detect motion of the UE 106, e.g., using any of a gyroscope, an accelerometer, and / or various other motion sensing components. As another possibility, the sensor circuitry 370 can include one or more temperature sensing components, e.g., to measure a temperature of each of one or more antenna panels and / or other components of the UE 106. Any of a variety of other possible types of sensor circuitry can also or alternatively be included in the UE 106, as desired. The processor 302 can also be coupled to a memory management unit (MMU) 340, which can be configured to receive addresses from the processor 302 and translate those addresses to locations in memory (e.g., memory 306, read-only memory (ROM) 350, NAND flash memory 310) and / or to other circuitry or devices, such as the display circuitry 304, the wireless communication circuitry 330, the connector interface (I / F) 320, and / or the display 360. The MMU 340 can be configured to perform memory protection and page table translation or set up. In some embodiments, the MMU 340 can be included as a portion of the processor 302.

[0077] As shown, the SOC 300 can be coupled to various other circuitry of the UE 106. For example, the UE 106 can include various types of memory (e.g., including NAND flash 310), a connector interface 320 (e.g., to couple to a computer system, a docking station, a charging station, etc.), a display 360, and wireless communication circuitry 330 (e.g., for LTE, LTE-A, NR, CDMA2000, BLUETOOTH TM(e.g., Wi-Fi, GPS, etc.). UE device 106 may include at least one antenna (e.g., 335a) and may include multiple antennas (e.g., shown by antennas 335a and 335b) for performing wireless communication with a base station and / or other devices. Antennas 335a and 335b are shown by way of example, and UE device 106 may include fewer or more antennas. Generally, one or more antennas are collectively referred to as antenna 335. For example, UE device 106 may use antenna 335 to perform wireless communication via radio circuitry 330. As described above, in some embodiments, the UE may be configured to use multiple wireless communication standards for wireless communication.

[0078] UE 106 may include hardware and software components, such as those described further herein, for implementing methods for reducing latency during IRAT reselection in a wireless communication system. The processor 302 of UE device 106 may be configured to implement some or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). In other embodiments, processor 302 may be configured as a programmable hardware element, such as a FPGA (Field-Programmable Gate Array) or as an ASIC (Application-Specific Integrated Circuit). Furthermore, as... Figure 3 As shown, processor 302 may be coupled to and / or interoperable with other components to reduce latency during IRAT reselection in a wireless communication system according to various embodiments disclosed herein. Processor 302 may also implement various other applications and / or end-user applications running on UE 106.

[0079] In some implementations, radio component 330 may include a separate controller dedicated to controlling communications for various corresponding RAT standards. For example, such as Figure 3 As shown, the radio component 330 may include a Wi-Fi controller 352, a cellular controller (e.g., an LTE, LTE-A, and / or NR controller) 354, and a BLUETOOTH controller. TM Controller 356, and in at least some embodiments, one or more of these controllers may be implemented as corresponding integrated circuits (referred to as ICs or chips), which communicate with each other and with the SOC 300 (more specifically with the processor 302). For example, Wi-Fi controller 352 may communicate with cellular controller 354 via a cell-ISM link or WCI interface, and / or BLUETOOTH TMController 356 can communicate with cellular controller 354 via a cell-ISM link or the like. Although three separate controllers are shown within radio component 330, other implementations with fewer or more similar controllers for various different RATs can be implemented in UE device 106.

[0080] Furthermore, implementation schemes in which the controller can perform functions associated with various radio access technologies are envisioned. For example, according to some implementation schemes, in addition to hardware and / or software components for performing cellular communications, the cellular controller 354 may also include hardware and / or software components for performing one or more activities associated with Wi-Fi, such as Wi-Fi preamble detection, and / or the generation and transmission of Wi-Fi physical layer preamble signals.

[0081] Figure 4 - block diagram of an exemplary base station

[0082] Figure 4 A block diagram of an exemplary base station 102 according to some implementation schemes is shown. It should be noted that... Figure 4 The base station shown is merely one example of a possible base station. As illustrated, base station 102 may include a processor 404 capable of executing program instructions specific to base station 102. Processor 404 may also be coupled to a memory management unit (MMU) 440 or other circuitry or device, which may be configured to receive addresses from processor 404 and translate those addresses into locations in memory (e.g., memory 460 and read-only memory (ROM) 450).

[0083] Base station 102 may include at least one network port 470. Network port 470 may be configured to be coupled to a telephone network and provide access rights as described above. Figure 1 and Figure 2 The telephone network described herein includes multiple devices such as UE device 106. Network port 470 (or an additional network port) may also be configured, or alternatively configured, to be coupled to a cellular network, such as the core network of a cellular service provider. The core network may provide mobility-related services and / or other services to multiple devices such as UE device 106. In some cases, network port 470 may be coupled to the telephone network via the core network, and / or the core network may provide the telephone network (e.g., in other UE devices served by the cellular service provider).

[0084] The base station 102 can include at least one antenna 434, and possibly multiple antennas. The antenna 434 can be configured to operate as a wireless transceiver and can also be configured to communicate with UE devices 106 via the radio 430. The antenna 434 communicates with the radio 430 via a communication chain 432. The communication chain 432 can be a receive chain, a transmit chain, or both. The radio 430 can be designed to communicate via various wireless telecommunication standards including, but not limited to, NR, LTE, LTE-A WCDMA, CDMA2000, etc. The processor 404 of the base station 102 can be configured to implement and / or support a portion or all of the methods described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, the processor 404 can be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit), or a combination thereof. In the case of certain RATs, such as Wi-Fi, the base station 102 can be designed to be an access point (AP), in which case the network port 470 can be implemented to provide access to a wide area network and / or one or more local area networks, for example it can include at least one Ethernet port, and the radio 430 can be designed to communicate according to Wi-Fi standards.

[0085] Figures 5-8 - Race conditions between call setup and IRAT reselection

[0086] Inter-Radio Access Technology (IRAT or inter-RAT) reselection can involve a UE, such as the UE 106, switching from camping on a cell of a first RAT (e.g., NR) to camping on a cell of a second RAT (e.g., LTE). During IRAT reselection from NR to LTE (or vice versa) or between other RATs, if a call setup is triggered for any reason (e.g., MO signaling, MO data, emergency, etc.), the resulting race condition can cause a call failure and / or delay in call setup that can be observed by the end user, depending on the specific implementation in the UE.

[0087] Certain aspects of the IRAT reselection procedure can be defined by applicable standards such as 3GPP TS 38.304 V16.5.0, which is hereby incorporated by reference in its entirety as if fully and completely disclosed herein. However, other aspects can not be defined by any standards, and thus can be implemented according to vendor preference. In the case of race conditions such as those outlined above, different UE vendors can implement different responses, and in a pristine UE implementation, the NR RRC layer can reject a call setup request or call resume request from the non-access stratum (NAS) layer when an IRAT reselection is in progress, which in turn can cause the NAS layer to also send a rejection to its upper layers. This can result in a call failure, which can be noticed by the end user.

[0088] Figures 5A-5B A signal flow diagram is shown that presents an example of such a pristine implementation when transitioning from NR to LTE. Figures 5A-5B A cellular network (NW) 516 and several different aspects of a UE such as the UE 106 are shown. A user interface 502 can include any type of user interface component of the UE that allows for initiating a user call and / or notifying of a call setup or failure. For example, the user interface 502 can be or include a touchscreen such as the display 360. A UE application processor (AP) 504 can include any processor configured to run application software capable of interacting with the user interface 502. For example, the UE AP 504 can be or include one or more of the processors 302.

[0089] A UE NAS 506 can represent hardware and / or software (e.g., modules) within the UE for implementing a non-access stratum layer of the UE. Similarly, a UE LTE radio resource control (RRC) 508 can represent hardware and / or software (e.g., modules) within the UE for implementing a RRC layer for LTE communications, while a UE NR RRC 510 can represent hardware and / or software (e.g., modules) within the UE for implementing a RRC layer for NR communications. A UE LTE LI 514 can represent hardware and / or software (e.g., modules) within the UE for implementing a physical layer (LI) for LTE communications, while a UE NR LI 512 can represent hardware and / or software (e.g., modules) within the UE for implementing a LI for NR communications. In some implementations, the UE NAS 506, the UE LTE RRC 508, the UE NR RRC 510, the UE NR LI 512, and / or the UE LTE LI 514 can be included in a cellular modem of the UE, e.g., within the wireless communication circuitry 330 or the cellular controller 354. For example, the cellular modem can include functionality, modules, etc. for implementing the illustrated elements 506-514.

[0090] like Figure 5A As shown, the UE begins with UE LTE L1 514 in L1_SLAVE mode (522) and UE NR L1 512 in L1_IDLE state (520). UE NR RRC 510 is in INACTIVE state (518). UE LTE L1 514 provides UE NR RRC 510 with an LTE L1 EUTRA measurement indication 524 to determine whether to perform IRAT reselection. In response, at 526, UE NR RRC 510 initiates the IRAT reselection procedure. For example, UE NR RRC 510 can determine T based on... 重新选择 An IRAT reselection process is initiated when the EUTRA has expired and a neighboring cell (e.g., an LTE cell) is prioritized over the current serving cell (e.g., an NR cell).

[0091] Independent of the IRAT reselection process, the user initiates the call by interacting with user interface 502. This causes user interface 502 to provide call setup instruction 528 to UE AP 504, which in turn provides call setup instruction 530 to UE NAS 506.

[0092] At some point thereafter, UE NR RRC 510 provides UE NAS 506 with an IRAT reselection initiation instruction 532. UE NR RRC 510 also provides UE LTE RRC 508 with a reselection request 534, and then waits for a return based on input from other RATs (LTE).

[0093] In this scenario, UE NAS 506 receives call setup instruction 530 before being notified of IRAT reselection. Therefore, UE NAS 506 completes the call setup process before proceeding with the IRAT reselection procedure. However, UE NRRRC 510 initiates the reselection procedure before receiving any notification of call initiation from UE NAS 506. Therefore, UE NRRRC 510 prioritizes the IRAT reselection procedure. Specifically, upon receiving call setup instruction 530, UE NAS 506 provides recovery request message 538 to UE NR RRC 510. Because UE NR RRC 510 is already in the process of performing IRAT reselection, it responds to UE NAS 506 with recovery rejection message 540.

[0094] Upon receipt of the message, UE NAS 506 provides a call failure message 544 to UE AP 504, and UE AP 504 provides the call failure message 544 message to user interface 502, e.g., for display to the user.

[0095] At this point, the IRAT reselection proceeds as normal. For example, the IRAT reselection is not affected by the failed call setup. As shown, UE LTE RRC 508 provides a reselection confirmation message 550 to UE NR RRC 510, and also provides a cell pre-emption indication 552 to UE NAS 506, indicating that the UE is now pre-empted on the LTE network. UE LTE RRC 508 then enters an IDLE state 554. UE LTE Ll 514 similarly enters an Ll IDLE state 558.

[0096] In response to the reselection confirmation 550, UE NR RRC 510 provides an Ll deactivation request message to UE NR Ll 512. UE NR RRC 510 then enters a DEACTIVATED state 560. UE NR Ll 512 enters an Ll DEACTIVATED state 562, and provides an Ll deactivation confirmation message 564 to UE NR RRC 510. In response, UE NR RRC 510 provides an IRAT reselection complete indication 566 to UE NAS 506.

[0097] Despite this successful completion of the IRAT reselection procedure, the user must re-initiate the failed call. For example, at 546, the user can notice the indication of the failed call on user interface 502, and can re-initiate the call at 568. In an average scenario, this can typically take a few seconds, e.g., 2-5 seconds. Thus, the IRAT reselection procedure can well be completed (successfully or unsuccessfully) before the second call initiation attempt. Thus, this second call initiation can proceed according to normal procedures, without further interference from the IRAT reselection procedure. For example, as shown, user interface 502 responds to the user input by providing a call setup message 570 to UE AP 504, which can be substantially similar to call setup message 528. The UE can then proceed to establish a call with the LTE cell according to normal procedures known in the art, as outlined at 572. Upon completion of the call setup, UE AP 504 provides a call connected message 574 to user interface 502, and user interface 502 can notify the user of the successful call setup.

[0098] In some use cases, the call failure and associated delay experienced in the example can be considered unacceptable. For example, certain call failure key performance indicators (KPIs) can be broken.

[0099] It will be appreciated that Figures 5A-5B The example of FIG. 5 illustrates an RRC resume procedure, but the signal flow would be substantially similar for an RRC connection setup procedure. Similarly, Figures 5A-5B The example of FIG. 5 illustrates an IRAT reselection from NR to LTE, but the signal flow would be substantially similar for IRAT reselection between LTE to NR or other RATs. Similarly, Figures 5A-5B The example of FIG. 5 illustrates a successful IRAT reselection procedure, but in scenarios where the IRAT reselection procedure fails, the effects observed by the user would be substantially similar.

[0100] To eliminate Figures 5A-5B In order to eliminate the unacceptable call failure and delay experienced in the example of FIG. 5, the UE can determine that the IRAT reselection is occurring concurrently with the connection setup or resume procedure, and can respond by temporarily suspending the connection setup or resume procedure. For example, the UE NR RRC can cache the NAS resume (or setup) request message until after the IRAT reselection is successful or failed, and then continue the resume / setup call. Or, the UE AP can cache call context information, such as the call setup message, until a notification is received that the IRAT reselection procedure is complete, and then continue the call setup. As another alternative, the UE NAS can cache the call setup message until a notification is received that the IRAT reselection procedure is complete, and then continue the resume / setup call. FIGS. 6-8 illustrate example scenarios implementing these alternatives, according to some embodiments.

[0101] Figures 6A-6C A signal flow diagram illustrating an example of a scenario in which the NR RRC layer caches the resume request message until the IRAT reselection is complete, according to some embodiments. Specifically, Figure 6A The initiation of the scenario is illustrated, up to the NR RRC layer caching the resume request message. Figure 6B An example signal flow is illustrated for completing the flow diagram of FIG. 5, in which the IRAT reselection fails. Figure 6A An alternative signal flow is illustrated for completing the flow diagram of FIG. 5, in which the IRAT reselection is successful. Figure 6C An alternative signal flow is illustrated for completing the flow diagram of FIG. 5, in which the IRAT reselection is successful. Figure 6A It will be appreciated that substantially similar flow diagrams can be applied in scenarios in which the connection setup request is cached.

[0102]

[0103] Figure 6A ​The various components of the UE and network shown can be used with Figure 5A The corresponding parts shown are similar or the same, except that Figure 6A The components have been improved to achieve Figures 6A-6C The solution is shown in the figure. For example, user interface 602 can be substantially similar to user interface 502, UE AP 604 can be substantially similar to UE AP 504, etc.

[0104] like Figure 6A As shown, the UE can begin when UE LTE L1 614 is in L1_SLAVE mode (624) and UE NR L1 612 is in L1_IDLE state (622). UE NR RRC 610 can begin in INACTIVE state (620), and UE LTE L1 RRC 610 can begin in DEACTIVATED state (618). UE LTE L1 614 can provide UE NR RRC 610 with LTE L1 EUTRA measurement indication 626 to determine whether to perform IRAT reselection. In response, at 628, UE NR RRC 610 can initiate the IRAT reselection procedure. For example, UE NR RRC 610 can determine T 重新选择 An IRAT reselection process is initiated when the EUTRA has expired and a neighboring cell (e.g., an LTE cell) is prioritized over the current serving cell (e.g., an NR cell).

[0105] Similar to Figure 5A Users can initiate calls by interacting with user interface 602. This allows user interface 602 to provide call setup instruction 630 to UE AP 604, which in turn can provide call setup instruction 632 to UE NAS 606.

[0106] At some point thereafter, UE NR RRC 610 may provide UE NAS 606 with an IRAT reselection initiation indication 634 to indicate that the IRAT reselection process has begun. UE NR RRC 610 may also provide UE LTE RRC 608 with a reselection request 636, and may then wait (638) for a return based on input from other RATs (LTE).

[0107] As in the scenario of FIG. 5, in which the UE NAS 606 receives the call setup instruction 632 prior to being notified of the IRAT reselection. Thus, the UE NAS 606 can act to complete the call setup procedure prior to acting in accordance with the IRAT reselection procedure. However, the UE NR RRC 610 can begin the reselection procedure prior to receiving any notification of the call initiation from the UE NAS 606. Thus, the UE NR RRC 610 can prioritize the IRAT reselection procedure. Specifically, upon receiving the call setup instruction 632, the UE NAS 606 can provide a resume request message 640 to the UE NR RRC 610.

[0108] In Figure 6A the scenario, the UE NR RRC 610 does not respond to the UE NAS 606 with a resume reject message. Rather, the UE NR RRC 610 can cache (or otherwise store) the resume request message 640 (or relevant information therefrom) at 642, e.g., in response to determining that the IRAT reselection procedure is pending (e.g., has begun but has not completed).

[0109] It will be appreciated that in some scenarios, the relative timing between the IRAT reselection procedure and the call setup procedure can vary without any meaningful change to the illustrated scenarios. For example, in some scenarios, the UE NAS 606 can provide the resume request message 640 prior to receiving the IRAT reselection initiation instruction 634. However, the UE NR RRC 610 can still respond to the resume request message 640 by caching the message, as the IRAT reselection procedure is already pending. The factors that form the relevant race condition are that the UE NAS 606 receives the call setup message 632 prior to being notified of the IRAT reselection, causing the UE NAS 606 to prioritize the call setup, and the UE NR RRC 610 initiates the IRAT reselection prior to receiving the resume request message 640, causing the UE NR RRC 610 to prioritize the IRAT reselection. The timing and sequence of the various messages can vary within these constraints while still resulting in the same race condition, and thus can still be addressed by the solutions presented herein.

[0110] Figure 6BThe remaining portions of the example signal flow diagram for the scenario in which the reselection procedure fails are shown. As shown, UE LTE RRC 608 can provide a reselection failure message 644 to UE NR RRC 610 in response to the reselection request 636. This can be due to the UE failing to camp on the LTE cell for any reason, for example. In response, UE NR RRC 610 can provide an IRAT reselection failure indication 648 to UE NAS 606. UE NR RRC 610 can also reinitiate camping on an NR cell at 650; e.g., on the original cell. UE NR RRC 610 can then return to the INACTIVE state (652), and UE LTE Ll 614 can return to the Ll_SLAVE state (656).

[0111] At this point, the reselection procedure is complete. Thus, UE NR RRC 610 can continue processing the resume request previously received. In particular, UE NR RRC 610 can process the resume request message 640 at 654, which was cached at 642. In some implementations, UE NR RRC 610 can process the resume request message 640 as if it was received after the IRAT reselection procedure is complete; e.g., after 652. For example, UE NR RRC 610 can provide an rrcResumeRequest message 658, or other message requesting resumption of the RRC connection with the NR cell, to NW 616.

[0112] In response, NW 616 can provide an rrcResume message 660, or other message indicating that the RRC connection with the NR cell on the network side has been resumed, to UE NR RRC 610, and UE NR Ll 612 can enter the Ll_CONNECTED state (662). UE NR RRC 610 can then provide an rrcResumeComplete message 664, or other message indicating that resumption of the RRC connection is complete on the UE side, to NW 616. UE NR RRC 610 can then enter the CONNECTED state (610), and UE LTE RRC can resume the DEACTIVATED state (666).

[0113] At this point, the UE NR RRC 610 can provide a resume confirmation message 670 to the UE NAS 606, indicating that the call has been successfully resumed. In response, the UE NAS 606 can provide a call connected message 672 to the UE AP 604, and the UE AP 604 can respond by providing a call connected message 674 to the user interface 602. In some scenarios, the user interface 602 can notify the user that the call setup was successful. As shown at 676, the call can then proceed via the established connection.

[0114] In this scenario, the average time elapsed between the call setup message 630 and the call connected message 674 can typically be in the range of 100ms-250ms. This represents a significant improvement over the typical 2-5 seconds for a user to reinitiate a call as discussed in connection with Figures 5A-5B Additionally, the scenario of Figures 6A-6B eliminates the need for the user to make a second attempt to initiate the call, resulting in an improved user experience.

[0115] In some scenarios, the reselection procedure can be successful, as opposed to the example of Figure 6B In some scenarios, the reselection procedure can be successful, as opposed to the example of Figure 6C An example of such a scenario is shown. Specifically, Figure 6C An example signal flow diagram of Figure 6A is shown for a scenario in which the reselection procedure is successful. Thus, Figure 6C The scenario of Figure 6B is an alternative scenario to the scenario of

[0116] As shown in Figure 6C , the UE LTE RRC 608 can provide a reselection confirmation message 645 to the UE NR RRC 610 in response to the reselection request 636, confirming that the reselection can proceed. The UE LTE RRC 608 can then enter an IDLE state (647). The UE LTE RRC 608 can also provide a cell pre-occupation indication 653 to the UE NAS 606, indicating that the UE is now pre-occupied on the LTE cell. The UE NAS 606 can respond at 655 by preparing for an inter-system change, e.g., N1-S1, as is known in the art.

[0117] In response to the reselection confirm message 645, the UE NR RRC 610 can provide an L1 deactivation request 657 to the UE NR LI 612. In response, the UE NR LI 612 can enter the L1 DEACTIVATED state (661), while the UE NR RRC 610 can enter the DEACTIVATED state (659). The UE NR LI 612 can then respond to the UE NR RRC 610 with an L1 deactivation confirm message 663. At this point, the UE NR RRC 610 can provide an IRAT reselection complete indication 665 to the UE NAS 606.

[0118] Once the IRAT reselection procedure is complete, the UE NR RRC 610 can process the resume request message 640, which is cached at 642. In some implementations, the UE NR RRC 610 can process the resume request message 640 as if it were received after the IRAT reselection procedure is complete (e.g., after 663 and / or 665). Because the UE is now camped on an LTE cell, the UE NR RRC 610 can provide a resume reject message 667 to the UE NAS 606 because the UE is unable to resume the connection to the NR cell.

[0119] In response, the UE NAS 606 can perform a NAS LTE registration procedure as known in the art, resulting in a call connection. For example, the procedure can include the UE NAS 606 providing an establish request, followed by network signaling such as rrcConnectionRequest, rrcConnectionSetup, and rrcConnectionSetupComplete messages, followed by the UE NAS 606 receiving an establish confirm message. At this point, the UE LTE RRC 608 can enter the CONNECTED state (671), and the UE LTE LI 614 can enter the L1 CONNECTED state (673).

[0120] The UE NAS 606 can provide a call connection message 675 to the UE AP 604, and the UE AP 604 can respond by providing a call connection message 677 to the user interface 602. In some scenarios, the user interface 602 can notify the user that the call setup was successful. The call can then proceed via the established connection.

[0121] In this scenario, as in the scenario of FIG. 6, the UE NR RRC 610 can provide an L1 deactivation request 657 to the UE NR LI 612 in response to the reselection confirm message 645. In response, the UE NR LI 612 can enter the L1 DEACTIVATED state (661), while the UE NR RRC 610 can enter the DEACTIVATED state (659). The UE NR LI 612 can then respond to the UE NR RRC 610 with an L1 deactivation confirm message 663. At this point, the UE NR RRC 610 can provide an IRAT reselection complete indication 665 to the UE NAS 606. Figure 6BAs in the example scenario of FIG. 6, the average time elapsed between the call setup message 630 and the call connect message 677 can generally be in the range of 100-250 ms. Thus, relative to Figures 5A-5B In the example scenario of FIG. 7, improvements in reducing latency and improving user experience can be achieved regardless of whether the reselection is successful.

[0122] Figures 7A-7B A signal flow diagram showing an example of presenting a scenario in which the UE AP caches a call setup message until receiving a cell pre-emption indication after IRAT reselection is shown in accordance with some embodiments. Figures 7A-7B The example scenario of FIG. 7 shows an RRC resume procedure in which the reselection is successful. It should be understood that similar approaches can be applied in scenarios including RRC connection establishment procedures and / or scenarios in which the reselection is not successful.

[0123] Figure 7A The various components of the UE and network shown in FIG. 8 can be similar or identical to the corresponding components shown in FIG. 7, except that Figure 6A The components shown in FIG. 8 can be configured to perform the alternative solutions shown in FIG. 7. For example, the user interface 802 can be substantially similar to the user interface 702, the UE AP 804 can be substantially similar to the UE AP 704, etc. Similarly, the signal exchanges shown at 818-840 can be substantially similar or identical to the corresponding signal exchanges shown at 718-740. Figure 7A Figures 7A-7B However, in the example of FIG. 8, the UE NR RRC 810 does not cache the resume request 840. Instead, the UE NR RRC 810 can respond by providing a resume reject message 842 to the UE NAS 806. The UE NAS 806 can then respond by providing a call failure message 844 to the UE AP 804. In some scenarios, the call failure message 844 can include an indication that the call failure was caused by a cell reselection or, more specifically, an IRAT reselection. In response to receiving the call failure message 844 indicating that the cause was a reselection, the UE AP 804 can cache (or otherwise store) call context information such as the setup message 832 (or relevant information from it) at 846, e.g., until the reselection is complete.

[0124] However, in the example of FIG. 8, the UE NR RRC 810 does not cache the resume request 840. Instead, the UE NR RRC 810 can respond by providing a resume reject message 842 to the UE NAS 806. The UE NAS 806 can then respond by providing a call failure message 844 to the UE AP 804. In some scenarios, the call failure message 844 can include an indication that the call failure was caused by a cell reselection or, more specifically, an IRAT reselection. In response to receiving the call failure message 844 indicating that the cause was a reselection, the UE AP 804 can cache (or otherwise store) call context information such as the setup message 832 (or relevant information from it) at 846, e.g., until the reselection is complete. Figure 7A

[0125] As in the example scenario of FIG. 6, the average time elapsed between the call setup message 630 and the call connect message 677 can generally be in the range of 100-250 ms. Thus, relative to Figure 7B ​​As shown, UE LTE RRC 708 can provide a reselection confirmation message 750 to UE NR RRC 710 in response to the reselection request 736, which confirms that the reselection can proceed. UE LTE RRC 708 can also provide a cell camp-on indication 752 to UE NAS 706 indicating that the UE is now camped on the LTE cell, and can enter an IDLE state (754). UE LTE Ll 714 can enter an Ll IDLE state (758).

[0126] In response to the reselection confirmation message 750, UE NR RRC 710 can provide an Ll deactivation request 756 to UE NR Ll 712. In response, UE NR Ll 712 can enter an Ll DEACTIVATED state (762), while UE NR RRC 710 can enter a DEACTIVATED state (760). UE NR Ll 712 can then respond to UE NR RRC 710 with an Ll deactivation confirmation message 764.

[0127] At this point, UE NR RRC 710 can provide an IRAT reselection complete indication 766 to UE NAS 706. In response, UE NAS 706 can provide a cell camp-on indication 768 to UE AP 704, which can indicate that the UE is now camped on the LTE cell.

[0128] Upon receiving notification of the IRAT reselection completion, e.g., via cell camp-on indication 768, UE AP 704 can reinitiate call setup at 770. For example, UE AP 704 can provide a call setup message 772 to UE NAS 706 that can be the same as call setup message 732 and / or other call context information cached at 746. The UE can then perform signaling as known in the art to establish a call with the LTE cell. Once the call has been successfully connected, UE AP 704 can provide a call connected message 776 to user interface 702.

[0129] In some scenarios, user interface 702 can notify the user that the call setup was successful. The call can then proceed via the established connection.

[0130] In scenarios where Figures 7A-7B As in scenarios Figure 6B and Figure 6C The average time elapsed between call setup message 730 and call connected message 776 can typically be in the range of 100-250 ms, as in scenarios Figures 7A-7BSimilar improvements can be achieved in scenarios where reselection fails.

[0131] Figures 8A-8B The diagram illustrates a signal flow diagram of an example scenario, based on some implementations, in which the UE NAS layer caches the call setup message until it receives the IRAT reselection completion indication. Figures 8A-8B The example scenario illustrates an RRC recovery process where reselection is successful. It should be understood that similar methods can be applied to scenarios including RRC connection establishment processes and / or scenarios where reselection is unsuccessful.

[0132] Figure 8A The various components of the UE and network shown can be used with Figure 6A The corresponding parts shown are similar or the same, except that Figure 8A The components shown can be configured to perform Figures 8A-8B The alternative solutions shown are as follows. For example, user interface 802 can be substantially similar to user interface 602, UE AP 804 can be substantially similar to UE AP 604, etc. Similarly, the signal exchanges shown at 718-740 can be substantially similar to or the same as the corresponding signal exchanges shown at 618-640.

[0133] like Figure 8A As shown, the UE can begin when UE NAS 804 is in NR_IDLE state (818), UE LTE L1 814 is in L1_SLAVE mode (826), and UE NR L1 812 is in L1_IDLE state (824). UE NR RRC 810 can begin in INACTIVE state (822), and UE LTE RRC 808 can begin in DEACTIVATED state (820). UE LTE L1 814 can provide LTE L1 EUTRA measurement indication 828 to UE NR RRC 810 to determine whether to perform IRAT reselection. In response, UE NR RRC 810 can initiate an IRAT reselection procedure at 830. For example, UE NR RRC 810 can determine T 重新选择 An IRAT reselection process is initiated when the EUTRA has expired and a neighboring cell (e.g., an LTE cell) is prioritized over the current serving cell (e.g., an NR cell).

[0134] Similar to Figure 6AUsers can initiate calls by interacting with user interface 802. This allows user interface 802 to provide call setup instruction 832 to UE AP 804, which in turn can provide call setup instruction 834 to UE NAS 806.

[0135] At some point thereafter, UE NR RRC 810 may provide UE NAS 806 with an IRAT reselection initiation indication 836 to indicate that the IRAT reselection process has begun. UE NR RRC 810 may also provide UE LTE RRC 808 with a reselection request 838, and may then wait (840) for a return based on input from other RATs (LTE).

[0136] As in Figure 6A Similar to the previous scenario, in which UE NAS 806 receives call setup instruction 834 before being notified of IRAT reselection. Therefore, UE NAS 806 can complete the call setup procedure before proceeding with the IRAT reselection procedure. However, UE NR RRC 810 can initiate the reselection procedure before receiving any notification of call initiation from UE NAS 806. Therefore, UE NR RRC 810 can prioritize the IRAT reselection procedure. Specifically, upon receiving call setup instruction 834, UE NAS 806 can provide UE NR RRC 810 with a recovery request message 842.

[0137] As in Figure 7A In the same scenario, UE NR RRC 810 can respond by providing UE NAS 806 with a recovery rejection message 844, which can indicate that the rejection was caused by cell reselection or, more specifically, by IRAT reselection. In response to receiving the recovery rejection message 844, UE NAS 806 can cache (or otherwise store) the call setup message 834 (or related information therefrom), for example, until the reselection is complete.

[0138] like Figure 8B As shown, UE LTE RRC 808 can provide UE NR RRC 810 with a reselection confirmation message 852 in response to a reselection request 838, which confirms that reselection can proceed. UE LTE RRC 808 can also provide UE NAS 806 with a cell pre-occupancy indication 858 indicating that the UE is now pre-occupied on an LTE cell, and can enter the IDLE state (854). UE LTE L1 814 can enter the L1_IDLE state (856).

[0139] In response to the cell pre-occupancy indication 858, the UE NAS 806 can prepare for an inter-system change, e.g., N1-S1, as known in the art, at 560.

[0140] Meanwhile, in response to the reselection confirmation message 852, the UE NR RRC 780 can provide an L1 deactivation request 862 to the UE NR L1 812. In response, the UE NR L1 812 can enter the L1 DEACTIVATED state (866), while the UE NR RRC 810 can enter the DEACTIVATED state (864). The UE NR L1 812 can then respond to the UE NR RRC 810 with an L1 deactivation confirmation message 868. The UE NR RRC 810 can respond by providing an IRAT reselection complete indication 870 to the UE NAS.

[0141] In response to the IRAT reselection complete indication 870, the UE NAS 806 can enter the LTE IDLE state (872). Also, upon receiving this notification of the IRAT reselection completion, the UE NAS 806 can reinitiate call setup at 874, e.g., by processing the call setup message 834 or related information therefrom that was cached at 846. In some embodiments, the UE NAS 806 can process the call setup message 834 as if the call setup message was received after the IRAT reselection procedure is completed, e.g., after 572. For example, the UE NAS 806 can provide an establishment request 876 to the UE LTE RRC 808.

[0142] The UE can then perform signaling to establish a call with the LTE cell, as known in the art. Once the call has been successfully connected, the UE NAS 806 can provide a call connection message 884 to the UE AP 804, as shown at 878. The UE AP 804 can then provide a call connection message 886 to the user interface 802.

[0143] In some scenarios, the user interface 802 can notify the user that the call setup was successful. The call can then proceed via the established connection.

[0144] In scenarios where the call setup message 832 and the call connection message 886 are received at the UE AP 804 and the UE NAS 806, respectively, as in the scenarios of Figures 8A-8B , the average time elapsed between the call setup message 832 and the call connection message 886 can typically be in the range of 100-250 ms, as in the scenarios of Figure 6B and Figure 6C In scenarios similar to the scenarios involving the RRC connection setup procedure and / or scenarios where the reselection is not successful, similar improvements can be realized. Figures 8A-8B ​

[0145] It is to be understood that the features of FIGS. 6-8 focus on resolving race conditions as described above. Various signals and other elements are shown to provide context and to illustrate example functionality. However, certain ones of the signals and other elements shown can be omitted, rearranged, or substituted for one another while still achieving the goal of reducing delay and / or improving user experience in the presence of race conditions between an IRAT reselection procedure and a call setup procedure. Such arrangements are intended to fall within the scope of the present disclosure.

[0146] Due to the reduction in call setup (resume) failures, the various methods shown and explained above can provide improved behavior as seen by end users. In the presence of the race conditions shown, call setup or resume delay is reduced. This can result in a reduction in KPI failures.

[0147] These methods can result in improved network resource usage if implemented by a significant percentage of UE manufacturers on the market in function.

[0148] Figures 9-10 - method for reducing latency under contention conditions

[0149] Figure 9 is a flowchart showing a method for reducing delay during IRAT reselection in the presence of race conditions, in accordance with some embodiments. Figure 9 The method of can be implemented by a cellular modem (or other cellular communication circuitry) of a UE, such as UE 106. For example, Figure 9 The method of can be implemented by radio 330 and / or cellular controller 354.

[0150] Note that while at least some elements of the method of are described using language that refers to use of communication techniques and / or features associated with 3GPP, LTE, and / or NR specification documents, such description is not intended to limit the present disclosure, and aspects of the method of can be used in any suitable wireless communication system, as desired. In various embodiments, some of the method elements shown can be performed simultaneously, in a different order than shown, can be omitted, replaced by other method elements, or combined with other method elements, as desired. Additional method elements can also be performed as desired. As shown, Figure 9 Aspects of the method of can operate as follows. Figure 9 Figure 9 At 902, the cellular modem can initiate an IRAT reselection procedure. For example, this can include one or more of the signals or other elements shown as any of elements 626-638 and / or 828-840 above, as well as other signals and / or procedures used to initiate an IRAT reselection procedure.

[0151] At 902, the cellular modem can initiate an IRAT reselection procedure. For example, this can include one or more of the signals or other elements shown as any of elements 626-638 and / or 828-840 above, as well as other signals and / or procedures used to initiate an IRAT reselection procedure.

[0152] ​At 904, the cellular modem can receive a request to initiate a call setup procedure. For example, this can correspond to a call setup message, e.g., as shown above as element 632 or element 834. In some scenarios, the request can be received while the IRAT reselection procedure is pending. In some scenarios, the request can be received at a time that is prior to the NAS layer of the UE being notified of the IRAT reselection procedure but late enough that the NAS layer does not communicate with the RRC layer in response to the request until the RRC layer has initiated the IRAT reselection procedure.

[0153] In some scenarios, the request can be received from an AP of the UE. In some scenarios, the request to initiate a call setup procedure can be explicitly initiated by a user, such as via a user interface of the UE. In other scenarios, the request can be initiated by the AP in response to a software function implemented by the AP.

[0154] At 906, the cellular modem can determine whether an IRAT reselection procedure is pending. If not, then at 908, the cellular modem can complete the call setup procedure, e.g., as known in the art.

[0155] However, if the cellular modem determines at 906 that an IRAT reselection procedure is pending (e.g., the IRAT reselection procedure has begun and has not yet ended), then the cellular modem can suspend processing of the call setup procedure at 910.

[0156] In some scenarios, suspending processing of the call setup procedure can include the RRC layer of the cellular modem caching (or otherwise storing) a request to resume a suspended call connection or a request to establish a new call connection. For example, suspending processing of the call setup procedure can correspond to a cache resume request message, as shown above at element 642. Suspending processing of the call setup procedure can similarly correspond to a cache call setup request message.

[0157] In some scenarios, suspending processing of the call setup procedure can include the NAS layer of the cellular modem caching (or otherwise storing) a call setup request message. For example, suspending processing of the call setup procedure can correspond to a cache call setup message 834, as shown at element 846.

[0158] At 912, the cellular modem can complete the IRAT reselection procedure. In some scenarios, completing the IRAT reselection procedure can include failing to switch to the new cell, e.g., if the IRAT reselection procedure is unsuccessful. For example, completing the IRAT reselection procedure can include one or more of the signals or other elements shown above as elements 644-652. In some scenarios, completing the IRAT reselection procedure can include camping on the new cell, e.g., if the IRAT reselection procedure is successful. For example, completing the IRAT reselection procedure can include one or more of the signals or other elements shown above as elements 645-665 or 852-572.

[0159] In response to completing the IRAT reselection procedure (or in response to determining that the IRAT reselection procedure is completed), the cellular modem can resume processing of the call setup procedure at 914. In some scenarios, resuming processing of the call setup procedure can include establishing the call on the original cell according to the original RAT, e.g., if the IRAT reselection procedure is unsuccessful. For example, resuming processing of the call setup procedure can include one or more of the signals or other elements shown above as elements 654-672. In some scenarios, resuming processing of the call setup procedure can include establishing the call on the new cell according to the new RAT, e.g., if the IRAT reselection procedure is successful. For example, resuming processing of the call setup procedure can include one or more of the signals or other elements shown above as elements 655, 667-675, 860, and / or 874-884.

[0160] Figure 10 is a flow diagram illustrating a method for reducing latency during IRAT reselection in the presence of race conditions, in accordance with some embodiments. Figure 10 The method of can be implemented by one or more processors, such as an application of a UE, such as the UE 106. For example, Figure 10 The method of can be implemented by the processor 302 or the UE AP 704.

[0161] Note that while at least some elements of the methods of are described in ways that involve using communication technologies and / or features associated with 3GPP, LTE, and / or NR specification documents, such description is not intended to limit the present disclosure, and aspects of the methods of can be used in any suitable wireless communication system, as desired. Figure 10 Note that while at least some elements of the methods of are described in ways that involve using communication technologies and / or features associated with 3GPP, LTE, and / or NR specification documents, such description is not intended to limit the present disclosure, and aspects of the methods of can be used in any suitable wireless communication system, as desired. Figure 10 In various embodiments, some of the method elements shown can be performed concurrently, in a different order than shown, may Figure 10 The method of can operate as follows.

[0162] At 1002, the processor can receive an initial request from a user interface component of the UE device to initiate a call setup procedure. For example, the initial request can comprise the signal shown above as element 730.

[0163] At 1004, the processor can provide a first request to initiate the call setup procedure to a cellular modem of the UE device. For example, the first request can comprise the signal shown above as element 732. In some scenarios, the first request can be responsive to the initial request of 1002. In other scenarios, 1002 can be omitted, and the first request 1004 can be responsive to a different stimulus, such as a software function executed by the processor.

[0164] At 1006, the processor can receive an indication from the cellular modem that the call setup procedure failed because the cellular modem is currently performing an IRAT reselection procedure. For example, the indication can comprise the signal shown above as element 744.

[0165] Responsive to the indication that the call setup procedure failed, the processor can store information about the requested call setup procedure at 1008. In some scenarios, the stored information can comprise the first request or information therefrom. In some scenarios, the stored information can comprise call context information based on the first request. In some scenarios, storing information about the requested call setup procedure can comprise the element shown above as element 746.

[0166] At 1010, the processor can receive an indication from the cellular modem that the IRAT reselection procedure is complete. In some scenarios, the indication that the IRAT reselection procedure is complete can comprise an indication that the UE device camped on a new cell and / or utilizes a new RAT, e.g., if the IRAT reselection procedure was successful. For example, the indication that the IRAT reselection procedure is complete can comprise the signal shown above as 768.

[0167] Responsive to the indication that the IRAT reselection procedure is complete, the processor can provide a second request to initiate the call setup procedure based on the stored call context information to the cellular modem at 1012. In some scenarios, the second request can be substantially similar or identical to the first request. In some scenarios, the second request can comprise the context information included in the first request. For example, the second request can comprise the signal shown above as 772. It should be noted that the second request can be provided later than the initial request is received at 1002 (in scenarios in which the initial request is received at 1002) without additional input from the user interface component.

[0168] At 1014, the processor can receive an indication of completion of the call setup procedure from the cellular modem, e.g., in response to the second request. In some scenarios, the indication of completion of the call setup procedure can include an indication of whether the call setup procedure was successful.

[0169] At 1016, the processor can provide an indication of completion of the call setup procedure to the user interface component, e.g., in response to the initial request. In some scenarios, the indication of completion of the call setup procedure can include an indication of whether the call setup procedure was successful.

[0170] It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled in a manner that minimizes the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly explained to users.

[0171] Any of the methods described herein for operating a user equipment (UE) can be the basis for a corresponding method for operating a base station, by interpreting each message / signal X received by the UE in the downlink as a message / signal X transmitted by the base station, and each message / signal Y transmitted by the UE in the uplink as a message / signal Y received by the base station.

[0172] Embodiments of the present disclosure can be implemented in any of various forms. For example, in some embodiments, the subject matter can be implemented as a computer- implemented method, a computer-readable memory medium, or a computer system. In other embodiments, the subject matter can be implemented using one or more custom-designed hardware devices such as ASICs. In other embodiments, the subject matter can be implemented using one or more programmable hardware elements such as FPGAs.

[0173] In some embodiments, a non-transitory computer-readable memory medium (e.g., a non-transitory memory element) can be configured to have stored thereon a program of instructions and / or data, wherein if executed by a computer system, the program of instructions causes the computer system to perform a method, such as any of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein, or any combination of such subsets.

[0174] In some embodiments, a device (e.g., a UE) can be configured to include a processor (or a set of processors) and a memory medium (or memory element), where the memory medium stores program instructions, where the processor is configured to read and execute the program instructions from the memory medium, where the program instructions are executable to implement any of the various method embodiments described herein (or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein, or any combination of such subsets). The device can be implemented in any of a variety of forms.

[0175] While the above embodiments have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be construed to include all such variations and modifications.

Claims

1. A method of expediting call setup, the method comprising: by a cellular modem of a user equipment (UE) device: initiating an inter radio access technology (IRAT) reselection procedure; while the IRAT reselection procedure is pending, receiving a request to initiate a call setup procedure; in response to determining that the IRAT reselection procedure is pending, suspending processing of the call setup procedure; completing the IRAT reselection procedure; and in response to determining that the IRAT reselection procedure is complete, resuming processing of the call setup procedure, wherein suspending processing of the call setup procedure includes a non-access stratum (NAS) layer of the cellular modem caching a call setup request message.

2. The method of claim 1, wherein suspending processing of the call setup procedure includes a radio resource control (RRC) layer of the cellular modem caching a request to resume a suspended call connection.

3. The method of claim 1, wherein suspending processing of the call setup procedure includes a radio resource control (RRC) layer of the cellular modem caching a request to establish a new call connection.

4. The method of claim 1, wherein completing the IRAT reselection procedure includes failing to handover to a new cell.

5. The method of claim 1, wherein completing the IRAT reselection procedure includes camping on a new cell.

6. The method of claim 5, wherein resuming the processing of the call setup procedure includes establishing a call on the new cell.

7. A user equipment (UE) device comprising: at least one processor; and a cellular modem communicatively coupled to the at least one processor, the cellular modem configured to: initiate an inter radio access technology (IRAT) reselection procedure; while the IRAT reselection procedure is pending, receive a request to initiate a call setup procedure from the at least one processor; in response to determining that the IRAT reselection procedure is pending, suspend processing of the call setup procedure; complete the IRAT reselection procedure; and in response to determining that the IRAT reselection procedure is complete, resume processing of the call setup procedure, wherein suspending processing of the call setup procedure includes a non-access stratum (NAS) layer module of the cellular modem storing a call setup request message.

8. The UE device of claim 7, wherein suspending processing of the call setup procedure includes a radio resource control (RRC) module of the cellular modem storing a request to resume a suspended call connection.

9. The UE device of claim 7, wherein suspending processing of the call setup procedure includes a radio resource control (RRC) module of the cellular modem storing a request to establish a new call connection.

10. The UE device of claim 7, wherein completing the IRAT reselection procedure includes failing to handover to a new cell. ​ ​ ​ 11. The UE device of claim 7, wherein completing the IRAT reselection procedure comprises camping on a new cell.

12. The UE device of claim 11, wherein resuming processing of the call setup procedure comprises establishing a call on the new cell.

13. A method of expediting call setup, the method comprising: by a processor of a user equipment (UE) device: providing, to a cellular modem of the UE device, a first request to initiate a call setup procedure; receiving, from the cellular modem, an indication that the call setup procedure failed because the cellular modem is currently performing an inter radio access technology (IRAT) reselection procedure; in response to the indication that the call setup procedure failed, storing information about the requested call setup procedure; in response to an indication from the cellular modem that the IRAT reselection procedure is complete, providing, to the cellular modem, a second request to initiate the call setup procedure based on the stored information, wherein storing information about the requested call setup procedure comprises a non-access stratum (NAS) layer of the cellular modem caching a call setup request message.

14. The method of claim 13, further comprising: receiving, from a user interface component of the UE device, an initial request to initiate the call setup procedure, wherein the first request is in response to the initial request, and wherein the second request is provided without additional input from the user interface component.

15. The method of claim 13, wherein the indication that the IRAT reselection procedure is complete comprises an indication that the UE device camped on a new cell.

16. The method of claim 13, wherein the stored information about the requested call setup procedure comprises the first request.

17. The method of claim 13, wherein the stored information about the requested call setup procedure comprises call context information about the requested call setup procedure.

18. The method of claim 13, further comprising: receiving, from the cellular modem, an indication that the call setup procedure is complete.

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