SYSTEM AND METHOD FOR RECEIVING CSI-RS / TRS INDICATION BY UE IN IDLE / INACTIVE MODE FOR IMPROVED PAGING RECEPTION - Patent application

Abstract

An example method for wireless communication; receiving, by a user device in a reduced power state, resource information for receiving a channel state information reference signal (CSI-RS) and a tracking reference signal (TRS); exiting the reduced power state to receive the CSI-RS and the TRS based on the resource information; synchronizing with a base station to receive a downlink control information message based on the received CSI-RS and TRS; receiving paging information in a first physical downlink shared channel (PDSCH) transmission based on the received downlink control information message; and determining whether paging information is present in the first physical downlink PDSCH transmission for the wireless device; Initiating a random access channel (RACH) procedure to create a radio resource control (RRC) connection based on a determination that paging information is present for the wireless device, and returning to a reduced power state based on a determination that paging information is not present for the wireless device.

Description

[Technical Field]

[0001] The present application relates to various apparatus, systems, and methods that assist in providing Channel State Information Reference Signal (CSI-RS) / Tracking Reference Signal (TRS) indications to mobile devices that are in a reduced power state, such as an idle or inactive state, to improve performance of paging procedures in cellular communication systems. [Background technology]

[0002] The use of wireless communication systems is rapidly increasing. In recent years, wireless devices such as smartphones and tablet computers have become increasingly sophisticated. In addition to supporting telephony functions, many mobile devices now provide Internet access, email, text messaging, and navigation using the global positioning system (GPS), and can run sophisticated applications that take advantage of these functionalities. In addition, many different wireless communication technologies and standards exist. Some examples of wireless communication standards include GSM, UMTS (e.g., relating to WCDMA or TD-SCDMA air interfaces), LTE, LTE Advanced (LTE-A), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), IEEE 802.11 (WLAN or Wi-Fi), BLUETOOTH™, and the like.

[0003] The ever-increasing number of features and functions being introduced into wireless communication devices creates a continuing need to improve both wireless communication and wireless communication devices. In addition to the communication standards mentioned above, there are additional wireless communication technologies under development, including fifth-generation (5G) New Radio (NR) communication, to increase coverage and better accommodate the increasing demands and range of anticipated uses of wireless communication. Thus, improvements in this area to support such developments and designs are desirable. Summary of the Invention

[0004] Aspects relate to apparatus, systems, and methods that assist a cellular network in providing CSI-RS / TRS indications to mobile devices that are in a reduced power state, such as an idle or inactive state, to improve performance of paging procedures in a cellular communication system.

[0005] Specifically, 5G / NR requires a mechanism to provide improved UE power performance for paging procedures, especially for user equipment (UE) in reduced power states such as the RRC_IDLE and / or RRC_INACTIVE states defined in 5G / NR. In a mobile network, when a UE has no ongoing data transmission for a period of time, the UE may enter the RRC_IDLE or RRC_INACTIVE state (e.g., in the case of 5G / NR) to conserve battery life. When new data arrives for the device, the network may attempt to "wake up" an idle or inactive mobile device by sending a so-called "paging" message, which the mobile device may then respond to. In 5G / NR, a UE that relies on synchronization signal blocks (SSBs) for its readiness should wake up to listen for incoming SSBs, but once awake and synchronized, the UE must remain awake until its own specific paging occasion (PO) arrives, and this additional "awake" time can significantly increase the UE's power / energy consumption.

[0006] Thus, according to certain aspects disclosed herein, a method for paging in a wireless system is disclosed, the method including: receiving, by a user device in a reduced power state, resource information for receiving a channel state information reference signal (CSI-RS) and a tracking reference signal (TRS); exiting, by the user device, from the reduced power state to receive the CSI-RS and the TRS based on the resource information; synchronizing, by the user device, with a base station to receive a downlink control information message based on the received CSI-RS and the TRS; receiving, by the user device, paging information in a first physical downlink shared channel (PDSCH) transmission based on the received downlink control information message; determining, by the user device, whether paging information is present in the first physical downlink PDSCH transmission for the user device; initiating, by the user device, a random access channel (RACH) procedure to create a radio resource control (RRC) connection based on a determination that paging information is present for the user device; and returning the user device to the reduced power state based on a determination that paging information is not present for the user device.

[0007] In some aspects, the method may further include receiving, at the user device in a reduced power state, a system information block (SIB) transmitted by the base station, the SIB including resource information for receiving CSI-RS and TRS for a set of two or more user devices. In other aspects, the user device itself may transmit a request for the SIB, for example, via a RACH preamble. In some aspects, the resource information for receiving CSI-RS and TRS may include predefined CSI-RS and TRS information (e.g., configuration including content selected from a set of predefined configuration information). In yet other aspects, the user device may receive a second PDSCH message transmitted by the base station prior to the first PDSCH message, the second PDSCH message including resource information for receiving CSI-RS and TRS. In yet other aspects, the user device may receive a physical downlink control channel (PDCCH) message transmitted by the base station, the PDCCH message including resource information for receiving CSI-RS and TRS, for example, the resource information included in the PDCCH message indicating a predefined CSI-RS and TRS pattern.

[0008] The techniques described herein may be implemented in and / or used in conjunction with several different types of devices, including, but not limited to, any of a cellular telephone, a wireless device, a tablet computer, a wearable computing device, a portable media player, and a variety of other computing devices.

[0009] This Summary is intended to provide a brief overview of some of the subject matter described in this document. Accordingly, it should be understood that the above features are merely examples and should not be construed as narrowing the scope or spirit of the subject matter described herein. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following Detailed Description, the drawings, and the claims.

[0010] A better understanding of the present subject matter may be obtained from the following detailed description of various embodiments when considered in conjunction with the following drawings. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 illustrates an example of a wireless communication system, according to some aspects. [Figure 2] FIG. 1 illustrates a base station (BS) in communication with a user equipment (UE) device, according to some aspects. [Figure 3] 1 is an example block diagram of a UE, in accordance with some aspects. [Figure 4] 1 is an example block diagram of a BS, according to some aspects. [Figure 5] FIG. 1 is an example block diagram of a cellular communication circuit, according to some aspects. [Figure 6] 1 is an example block diagram of a network element, according to some aspects. [Figure 7] FIG. 10 is an example communication flow diagram of the communication flow for entering and resuming from an RRC_INACTIVE state. [Figure 8] 1 is an exemplary UE power consumption graph while waiting for a paging occasion (PO). [Figure 9] 1 is an example improved UE power consumption graph while waiting for a PO, in accordance with some aspects. [Figure 10] 1 illustrates an example NZP-CSI-ResourceConfig-IdleUE information element (IE) structure to be used for a UE in RRC_IDLE or RRC_INACTIVE state, in accordance with some aspects. [Figure 11]FIG. 10 illustrates an example use of different NZP-CSI-ResourceConfig-IdleUE IEs for multiple UEs in RRC_IDLE or RRC_INACTIVE state corresponding to different NZP-CSI-RS-ResourceSets from different UEs in RRC_CONNECTED mode, according to some aspects. [Figure 12] 10 illustrates an additional approach for performing a QCL indication for a UE in an RRC_IDLE or RRC_INACTIVE mode, according to some aspects. [Figure 13] FIG. 10 illustrates an approach using PDSCH to convey CSI-RS / TRS resource information, according to some aspects. [Figure 14] 1 is an example flowchart for receiving CSI-RS and TRS resource information by a UE in a reduced power state, such as an RRC_IDLE or RRC_INACTIVE mode, in accordance with some aspects. [Figure 15] 10 is an example flowchart of various methods for a user device to receive CSI-RS and TRS resource information while in a reduced power state, such as an RRC_IDLE or RRC_INACTIVE mode, according to some aspects. [Figure 16] 1 is an example flowchart for transmitting CSI-RS and TRS resource information from a base station to a UE in a reduced power state, such as an RRC_IDLE or RRC_INACTIVE mode, in accordance with some aspects. [Figure 17] 10 is an example flowchart of various methods for a base station to transmit CSI-RS and TRS resource information to a UE in a reduced power state, such as an RRC_IDLE mode or an RRC_INACTIVE mode, in accordance with some aspects.

[0012] While the features described herein may be susceptible to various modifications and alternative forms, specific forms of those features have been shown by way of example and are described in detail herein. It should be understood, however, that the drawings and detailed description are not intended to limit the invention to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present subject matter as defined by the appended claims. DETAILED DESCRIPTION OF THE INVENTION

[0013] The following is a glossary of terms that may be used in this disclosure.

[0014] Memory medium—any of various types of non-transitory memory or storage devices. The term “memory medium” is intended to include, for example, installation media such as CD-ROMs, floppy disks, or tape drives; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM; non-volatile memory such as magnetic media such as flash, hard drives, or optical storage; registers, or other similar types of memory elements. Memory media may also include other types of non-transitory memory, or combinations thereof. Additionally, memory media may be located in a first computer system on which a program is executed, or in a second, different computer system connected to the first computer system via a network such as the Internet. In the latter case, the second computer system may provide program instructions for execution by the first computer. The term “memory medium” may also include two or more memory media that can reside in different locations, for example, in different computer systems connected via a network. A memory medium may store program instructions (e.g., embodied as a computer program) that can be executed by one or more processors.

[0015] Carrier Medium - memory media as described above, as well as physical transmission media such as buses, networks, and / or other physical transmission media that carry signals, such as electrical, electromagnetic, or digital signals.

[0016] Programmable Hardware Element—includes a variety of hardware devices with multiple programmable function blocks connected via programmable interconnects. Examples include Field Programmable Gate Arrays (FPGAs), Programmable Logic Devices (PLDs), Field Programmable Object Arrays (FPOAs), and Complex PLDs (CPLDs). Programmable function blocks can range in granularity from fine-grained (combinational logic or lookup tables) to coarse-grained (arithmetic logic units or processor cores). Programmable hardware elements may also be referred to as “reconfigurable logic.”

[0017] Computer System—Any of various types of computing or processing systems, including a personal computer system (PC), mainframe computer system, workstation, network appliance, Internet appliance, personal digital assistant (PDA), television system, grid computing system, or other device or combination of devices. In general, the term “computer system” can be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

[0018] 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™, Android™-based phones), portable gaming devices (e.g., Nintendo DS™, PlayStation Portable™, Gameboy Advance™, iPhone™), laptop computers, wearable devices (e.g., smart watches, smart glasses), PDAs, portable Internet devices, music players, data storage devices, or other handheld devices. In general, the terms "wireless node," "UE," or "UE device" can be broadly defined to encompass any electronic, computing, and / or telecommunications device (or combination of devices) that is easily carried by a user and capable of wireless communications.

[0019] Wireless Device—Any of various types of computer systems or devices that perform wireless communications. A wireless device can be portable (or mobile) or may be stationary or fixed to a location. A UE is an example of a wireless device.

[0020] Communications Device - Any of various types of computer systems or devices that perform communications, which may be wired or wireless. A communications device may be portable (or mobile), or may be stationary or fixed to a particular location. A wireless device is one example of a communications device. A UE is another example of a communications device.

[0021] Base Station - The term "base station" has all of its ordinary meanings and includes at least a wireless communication station that is installed at a fixed location and used for communication as part of a wireless telephone or wireless system. Note that, for example, if a base station is implemented in an LTE context, it may alternatively be referred to as a "node," "eNodeB," or "eNB." If a base station is implemented in a 5G NR context, it may alternatively be referred to as a "node," "gNodeB," or "gNB."

[0022] Processing Element (or Processor)—refers to various elements or combinations of elements capable of performing functions in a device such as user equipment or a cellular network device. A processing element may include, for example, a processor and associated memory, portions or circuitry of an individual processor core, an entire processor core, an individual processor, a processor array, circuitry such as an Application Specific Integrated Circuit (ASIC), a programmable hardware element such as a Field Programmable Gate Array (FPGA), and various combinations of the above.

[0023] Channel—A medium used to convey information from a sender (transmitter) to a receiver. Note that because the characteristics of the term “channel” may vary according to different wireless protocols, as used herein, the term “channel” is considered to be used consistent with the standard for the type of device with which the term is used. In some standards, channel width may be variable (e.g., depending on device capabilities, band conditions, etc.). For example, LTE may support scalable channel bandwidths from 1.4 MHz to 20 MHz. In contrast, WLAN channels may have a 22 MHz width, and Bluetooth channels may have a 1 MHz width. Other protocols and standards may include different channel definitions. Furthermore, some standards may define and use multiple types of channels, e.g., different channels for uplink or downlink, and / or different channels for different uses, such as data, control information, etc.

[0024] Band - The term "band" has the full scope of the ordinary meaning of band and includes at least a portion of the spectrum (e.g., the radio frequency spectrum) in which channels are used for a purpose or set aside for the same purpose.

[0025] Automatically—refers to an action or operation performed by a computer system (e.g., software executed by a computer system) or device (e.g., a circuit, programmable hardware element, ASIC, etc.) without user input directly specifying or executing the action or operation. Thus, the term “automatically” contrasts with an operation that is manually performed or specified by a user, where the user provides input to directly perform the operation. An automatic procedure may be initiated by input provided by a user, but the subsequent actions performed “automatically” are not specified by the user; that is, they are not performed “manually,” with the user specifying each action to be performed. For example, a user filling out an electronic form by selecting each field and providing input specifying information (e.g., by typing information, selecting checkboxes, selecting radio selections, etc.) is considered manually filling out the form, even though the computer system must update the form in response to the user actions. A form may also be automatically filled out by a computer system, where the computer system (e.g., software executed on the computer system) analyzes the form's fields and fills out the form without user input specifying answers to the fields. As noted above, a user can invoke automatic form filling but is not involved in the actual filling of the form (e.g., the user does not manually specify answers in fields, but rather the answers are completed automatically). This specification provides various examples of actions that are automatically performed in response to actions taken by a user.

[0026] Approximately—refers to a value that is nearly accurate or precise. For example, approximately may refer to a value that is within 1-10 percent of a precise (or desired) value. Note, however, that the actual threshold (or tolerance) may depend on the application. For example, in some embodiments, "approximately" may mean within 0.1% of some specified or desired value, while in other forms the threshold may be, e.g., 2%, 3%, 5%, etc., as desired or required by the particular application.

[0027] Concurrency—refers to parallel execution or performance in which tasks, processes, or programs execute in an at least partially overlapping manner. For example, concurrency may be implemented using “strong” or strict parallelism, where tasks are executed (at least partially) in parallel on respective computing elements, or “weak parallelism,” where tasks are executed in an interleaved manner, e.g., by time-division multiplexing of execution threads.

[0028] Configured to—Various components may be described as being “configured to” perform a task or tasks. In this context, “configured to” is a broad description that generally means “having the structure” to perform a task or tasks during operation. Thus, a component may be configured to perform a task even when the component is not currently performing the task (e.g., a set of conductors may be configured to electrically connect a module to another module even when the two modules are not connected). In some contexts, “configured to” may be a broad description of a structure that generally means “having the circuitry” to perform a task or tasks during operation. Thus, a component may be configured to perform a task even when the component is not currently on. In general, the circuitry forming the structure corresponding to “configured to” may include hardware circuitry.

[0029] In the description herein, for convenience, various components may be described as performing a task or tasks. Such descriptions should be construed to include the phrase "configured to." It is expressly intended that a description of a component being configured to perform one or more tasks does not invoke 35 U.S.C. 112(f) interpretation with respect to that component.

[0030] Communication system example

[0031]

[0021] Referring now to Figure 1, a simplified example of a wireless communication system is shown, in accordance with some aspects. It should be noted that the system of Figure 1 is merely one example of a possible system, and that features of the present disclosure may be implemented in any of a variety of systems, as desired.

[0032] As shown, this example wireless communication system includes a base station 102A that communicates over a transmission medium with one or more user devices 106A, 106B, etc. through 106N. Each of the user devices may be referred to herein as a "user equipment" (UE). Accordingly, the user devices 106 are referred to as UEs or UE devices.

[0033] The base station (BS) 102A may be a base transceiver station (BTS) or cell site (cellular base station), and may include hardware that enables wireless communication with the UEs 106A-106N.

[0034] The communication area (or coverage area) of a base station may be referred to as a “cell.” The base station 102A and the UE 106 may be configured to communicate over a transmission medium using any of a variety of radio access technologies (RATs), also referred to as radio communication technologies or telecommunications standards, such as GSM, UMTS (e.g., relating to a WCDMA or TD-SCDMA air interface), LTE, LTE-Advanced (LTE-A), 5G New Radio (5G NR), HSPA, or 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), among others.

[0035] As shown, the base station 102A may also be equipped to communicate with a network 100 (e.g., a cellular service provider's core network, a telecommunications network such as the Public Switched Telephone Network (PSTN), and / or the Internet, among other possibilities). Thus, the base station 102A may facilitate communications between user devices and / or between the user devices and the network 100. In particular, the cellular base station 102A may provide various telecommunications capabilities to the UE 106, such as voice, SMS, and / or data services.

[0036] Base station 102A and other similar base stations (such as base stations 102B-102N) operating according to the same or different cellular communication standards may be provided as a network of cells that can provide continuous or near-continuous overlaid services to UEs 106A-106N and similar devices via one or more cellular communication standards over a geographic area.

[0037] Thus, as shown in FIG. 1, base station 102A may function as a "serving cell" for UEs 106A-N, and each UE 106 may also receive signals from (within range, if possible) one or more other cells, which may also be referred to as "neighboring cells" (which may be provided by base stations 102B-N and / or any other base stations). Such cells may also facilitate communication between user devices and / or between user devices and network 100. Such cells may include "macro" cells, "micro" cells, "pico" cells, and / or cells providing various other granularities of coverage area size. For example, base stations 102A-102B shown in FIG. 1 may be macro cells, and base station 102N may be a micro cell. Other configurations are possible.

[0038] In some aspects, the base station 102A may be a next-generation base station, such as a 5G New Radio (5G NR) base station, or "gNB." In some aspects, the gNB may be connected to a legacy Evolved Packet Core (EPC) network and / or an NR Core (NRC) / 5G Core (5GC) network. In addition, a gNB cell may include one or more Transition and Reception Points (TRPs). In addition, a UE capable of operating according to 5G NR may be connected to one or more TRPs in one or more gNBs. For example, the base station 102A and one or more other base stations 102 may be capable of supporting combined transmissions such that the UE 106 may receive transmissions from multiple base stations (and / or multiple TRPs served by the same base station). For example, as shown in FIG. 1, both base station 102A and base station 102C are shown serving the UE 106A.

[0039] It should be noted that the UE 106 may be capable of communicating using multiple wireless communication standards. For example, the UE 106 may be configured to communicate using at least one cellular communication protocol (e.g., GSM, UMTS (e.g., associated with a WCDMA or TD-SCDMA air interface), LTE, LTE-A, 5G NR, HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), etc.), in addition to wireless networking (e.g., Wi-Fi) and / or peer-to-peer wireless communication protocols (e.g., Bluetooth, Wi-Fi peer-to-peer, etc.). The UE 106 may also, or alternatively, be configured to communicate using one or more global navigation satellite systems (GNSS, e.g., GPS or GLONASS), one or more mobile television broadcast standards (e.g., ATSC-M / H), and / or any other wireless communication protocol, if desired. Other combinations of wireless communication standards (including three or more wireless communication standards) are also possible.

[0040] User Equipment (UE) Example

[0041] 2 illustrates a user equipment 106 (e.g., one of devices 106A-106N) in communication with a base station 102, according to some aspects. The UE 106 may be a device with cellular communication capabilities, such as a mobile phone, a handheld device, a computer, a laptop, a tablet, a smart watch or other wearable device, or virtually any type of wireless device.

[0042] The UE 106 may include a processor (processing element) configured to execute program instructions stored in memory. The UE 106 may perform any of the method aspects described herein by executing such stored instructions. Alternatively, or in addition, the UE 106 may include a programmable hardware element, such as a field programmable gate array (FPGA), an integrated circuit, and / or any of a variety of other possible hardware components configured to perform any of the method aspects described herein, or any portion of any of the method aspects described herein (e.g., individually or in combination).

[0043] The UE 106 may include one or more antennas for communicating using one or more wireless communication protocols or technologies. In some aspects, the UE 106 may be configured to communicate using, for example, NR or LTE using at least some shared radio components. As a further possibility, the UE 106 may be configured to communicate using CDMA2000 (1xRTT / 1xEV-DO / HRPD / eHRPD) or LTE using a single shared radio, and / or using either GSM or LTE using a single shared radio. The shared radio may be coupled to a single antenna or to multiple antennas (e.g., for MIMO) to perform wireless communication. In general, a radio may include any combination of a baseband processor, analog RF signal processing circuitry (e.g., including filters, mixers, oscillators, amplifiers, etc.), or digital processing circuitry (e.g., for digital modulation and other digital processing). Similarly, a radio may implement one or more receive and transmit chains using the hardware described above. For example, the UE 106 may share one or more portions of its receive and / or transmit chains between multiple wireless communication technologies, such as those mentioned above.

[0044] In some aspects, the UE 106 may include a separate transmit and / or receive chain (e.g., including separate antennas and other radio mechanism components) for each wireless communication protocol the UE 106 is configured to communicate using. As a further possibility, the UE 106 may include one or more radios shared among multiple wireless communication protocols and one or more radios used only by a single wireless communication protocol. For example, the UE 106 may include a shared radio for communicating using either LTE or 5G NR (or either LTE or 1xRTT, or LTE or GSM, among other possibilities), and a separate radio for communicating using each of Wi-Fi and Bluetooth. Other configurations are possible.

[0045] Communication Device Examples

[0046] FIG. 3 illustrates a block diagram of a simplified example of a communication device 106, according to some aspects. Note that the communication device block diagram of FIG. 3 is merely one example of a possible communication device. According to aspects, the communication device 106 may be, among other devices, a user equipment (UE) device, a mobile device or station, a wireless device or station, a desktop computer or computing device, a mobile computing device (e.g., a laptop computer, a notebook computer, or a portable computing device), a tablet, and / or a combination of devices. As shown in the figure, the communication device 106 may include a set of components 300 configured to perform core functions. For example, the set of components may be implemented as a system on chip (SOC), which may include portions for various purposes. Alternatively, the set of components 300 may be implemented as separate components or groups of components for various purposes. The set of components 300 may be coupled (e.g., communicatively, directly or indirectly) to various other circuits of the communication device 106.

[0047] For example, communication device 106 may include various types of memory (including, e.g., NAND flash 310), input / output interfaces such as connector I / F 320 (e.g., for connecting to a computer system, a dock, a charging station, input devices such as a microphone, a camera, a keyboard, output devices such as a speaker, etc.), a display 360 that may be integrated with communication device 106 or may be external, and wireless communication circuitry 330 (e.g., for LTE, LTE-A, NR, UMTS, GSM, CDMA2000, Bluetooth, Wi-Fi, NFC, GPS, etc.). In some aspects, communication device 106 may include wired communication circuitry (not shown), such as a network interface card for Ethernet.

[0048] Wireless communication circuitry 330 may be communicatively coupled (e.g., directly or indirectly) to one or more antennas, such as antenna(s) 335, as shown. Wireless communication circuitry 330 may include cellular and / or short- to medium-range wireless communication circuitry, and may include, for example, multiple receive chains and / or multiple transmit chains for receiving and / or transmitting multiple spatial streams in a Multiple-Input Multiple Output (MIMO) configuration.

[0049] In some aspects, as described further below, the cellular communication circuit 330 may include one or more receive chains (e.g., a first receive chain for LTE and a second receive chain for 5G NR) for multiple RATs (including and / or communicatively coupled (e.g., directly or indirectly) to dedicated processors and / or radios). Additionally, in some aspects, the cellular communication circuit 330 may include a single transmit chain that can be switched between radios dedicated to particular RATs. For example, a first radio may be dedicated to a first RAT, such as LTE, and be in communication with a dedicated receive chain and transmit chain shared with a second radio. A second radio may be dedicated to a second RAT, such as 5G NR, and be in communication with a dedicated receive chain and a shared transmit chain.

[0050] Communication device 106 may also include and / or be configured for use with one or more user interface elements, which may include any of a variety of elements, such as a display 360 (which may be a touchscreen display), a keyboard (which may be a separate keyboard or may be implemented as part of the touchscreen display), a mouse, a microphone and / or speaker, one or more cameras, one or more buttons, and / or any of a variety of other elements capable of providing information to a user and / or receiving or interpreting user input.

[0051] The communication device 106 may further include one or more smart cards 345 that include SIM (Subscriber Identity Module) functionality, such as one or more UICC(s) (Universal Integrated Circuit Card(s)) cards 345.

[0052] As shown, the SOC 300 may include processor(s) 302 that may execute program instructions for the communication device 106 and display circuitry 304 that may perform graphics processing and provide display signals to a display 360. The processor(s) 302 may be coupled to a memory management unit (MMU) 340, which may be configured to receive addresses from the processor(s) 302 and translate those addresses to locations in memory (e.g., memory 306, read only memory (ROM) 350, NAND flash memory 310) and / or other circuits or devices, such as the display circuitry 304, wireless communication circuitry 330, connector I / F 320, and / or display 360. The MMU 340 may be configured to perform memory protection and page table translation or setup. In some aspects, the MMU 340 may be included as part of the processor(s) 302.

[0053] As described above, the communication device 106 may be configured to communicate using wireless and / or wired communication circuitry. As described herein, the communication device 106 may include hardware and software components for implementing any of the various features and techniques described herein. The processor 302 of the communication device 106 may be configured to implement some or all of the features described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively (or in addition), the processor 302 may be configured as a programmable hardware element, such as a field programmable gate array (FPGA), or as an application-specific integrated circuit (ASIC). Alternatively (or in addition), the processor 302 of the communication device 106 may be configured to implement some or all of the features described herein in cooperation with one or more of the other components 300, 304, 306, 310, 320, 330, 340, 345, 350, and 360.

[0054] Additionally, as described herein, processor 302 may include one or more processing elements. Accordingly, processor 302 may include one or more integrated circuits (ICs) configured to perform the functions of processor 302. Additionally, each integrated circuit may include circuitry (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of processor(s) 302.

[0055] Further, as described herein, the wireless communication circuit 330 may include one or more processing elements. In other words, the wireless communication circuit 330 can include one or more processing elements. Thus, the wireless communication circuit 330 can include one or more integrated circuits (ICs) configured to perform the functions of the wireless communication circuit 330. In addition, each integrated circuit can include a circuit (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of the wireless communication circuit 330.

[0056] Base station example

[0057] 4 illustrates an example block diagram of a base station 102, according to some aspects. Note that the base station of FIG. 4 is merely one example of a possible base station. As shown, the base station 102 may include a processor(s) 404 that can execute program instructions for the base station 102. The processor(s) 404 may also be coupled to a memory management unit (MMU) 440 that may be configured to receive addresses from the processor(s) 404 and translate those addresses to locations in memory (e.g., memory 460 and read-only memory (ROM) 450) or other circuits or devices.

[0058] The base station 102 may include at least one network port 470. The network port 470 may be configured to couple to a telephone network and provide devices, such as the UE devices 106, with access to the telephone network as described above in FIGS.

[0059] Network port 470 (or additional network ports) may also, or alternatively, be configured to couple to a cellular network, such as a cellular service provider's core network. 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 a telephone network via the core network, and / or the core network may provide telephone service (e.g., among other UE devices served by the cellular service provider).

[0060] In some aspects, the base station 102 may be a next-generation base station, such as a 5G New Radio (5G NR) base station, or "gNB." In such aspects, the base station 102 may connect to a legacy Evolved Packet Core (EPC) network and / or an NR Core (NRC) / 5G Core (5GC) network. In addition, the base station 102 may be considered a 5G NR cell and may include one or more Transition and Reception Points (TRPs). In addition, a UE capable of operating according to 5G NR may connect to one or more TRPs in one or more gNBs.

[0061] The base station 102 may include at least one antenna 434, and possibly multiple antennas. The at least one antenna 434 may be configured to operate as a wireless transceiver and may be further configured to communicate with the UE device 106 via a radio 430. The antenna 434 communicates with the radio 430 via a communication chain 432. The communication chain 432 may be a receive chain, a transmit chain, or both. The radio 430 may be configured to communicate via various wireless communication standards, including, but not limited to, 5G NR, LTE, LTE-A, GSM, UMTS, CDMA2000, Wi-Fi, etc.

[0062] The base station 102 may be configured to communicate wirelessly using multiple wireless communication standards. In some cases, the base station 102 may include multiple radios, which may enable the base station 102 to communicate according to multiple wireless communication technologies. For example, in one possibility, the base station 102 may include an LTE radio for performing communications according to LTE and a 5G NR radio for performing communications according to 5G NR. In such a case, the base station 102 may be capable of operating as both an LTE base station and a 5G NR base station. In another possibility, the base station 102 may include a multimode radio, which may be capable of performing communications according to any of multiple wireless communication technologies (e.g., 5G NR and LTE, 5G NR and Wi-Fi, LTE and Wi-Fi, LTE and UMTS, LTE and CDMA2000, UMTS and GSM, etc.).

[0063] As described further herein below, the BS 102 may include hardware and software components for implementing or supporting the implementation of the features described herein. The processor 404 of the base station 102 may be configured to implement or support the implementation of 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). Alternatively, the processor 404 may be configured as a programmable hardware element, such as a field programmable gate array (FPGA), or as an application-specific integrated circuit (ASIC), or a combination thereof. Alternatively (or in addition), the processor 404 of the BS 102, together with one or more of the other components 430, 432, 434, 440, 450, 460, 470, may be configured to implement or support the implementation of some or all of the features described herein.

[0064] Additionally, as described herein, the processor(s) 404 may include one or more processing elements. Accordingly, the processor(s) 404 may include one or more integrated circuits (ICs) configured to perform the functions of the processor(s) 404. Additionally, each integrated circuit may include circuitry (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of the processor(s) 404.

[0065] Further, as described herein, radio 430 may include one or more processing elements. Accordingly, radio 430 may include one or more integrated circuits (ICs) configured to perform the functions of radio 430. Additionally, each integrated circuit may include circuitry (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of radio 430.

[0066] Cellular communication circuit example

[0067] FIG. 5 illustrates an example simplified block diagram of cellular communication circuitry according to some aspects. Note that the cellular communication circuitry block diagram of FIG. 5 is merely one example of possible cellular communication circuitry. Other circuitry is possible, such as circuitry including or coupled to a sufficient number of antennas for different RATs to perform uplink activity using separate antennas, or circuitry including or coupled to a fewer number of antennas that may be shared among multiple RATs, for example. According to some aspects, the cellular communication circuitry 330 may be included in a communication device such as the communication device 106 described above. As noted above, the communication device 106 may be a user equipment (UE) device, a mobile device or mobile station, a wireless device or wireless base station, a desktop computer or computing device, a mobile computing device (e.g., a laptop, notebook, or portable computing device), a tablet, and / or a combination of devices, among other devices.

[0068] The cellular communication circuitry 330 may be communicatively coupled (e.g., communicatively, directly or indirectly) to one or more antennas, such as antennas 335a-b and 336, as shown. In some aspects, the cellular communication circuitry 330 may include dedicated receive chains (e.g., a first receive chain for LTE and a second receive chain for 5G NR) for multiple RATs (e.g., including a dedicated processor and / or radio and / or communicatively coupled, directly or indirectly to a dedicated processor and / or radio). For example, as shown in FIG. 5, the cellular communication circuitry 330 may include a first modem 510 and a second modem 520. The first modem 510 may be configured to communicate according to a first RAT, e.g., LTE or LTE-A, etc., and the second modem 520 may be configured to communicate according to a second RAT, e.g., 5G NR, etc.

[0069] As shown, the first modem 510 may include one or more processors 512 and a memory 516 in communication with the processor 512. The modem 510 may be in communication with a radio frequency (RF) front end 530. The RF front end 530 may include circuitry for transmitting and receiving wireless signals. For example, the RF front end 530 may include receive circuitry (RX) 532 and transmit circuitry (TX) 534. In some aspects, the receive circuitry 532 may be in communication with a downlink (DL) front end 550, which may include circuitry for receiving wireless signals via an antenna 335a.

[0070] Similarly, the second modem 520 may include one or more processors 522 and a memory 526 in communication with the processor 522. The modem 520 may be in communication with an RF front end 540. The RF front end 540 may include circuitry for transmitting and receiving wireless signals. For example, the RF front end 540 may include receive circuitry 542 and transmit circuitry 544. In some aspects, the receive circuitry 542 may be in communication with a DL front end 560, which may include circuitry for receiving wireless signals via the antenna 335b.

[0071] In some aspects, a switch 570 may couple the transmit circuitry 534 to an uplink (UL) front end 572. Additionally, the switch 570 may couple the transmit circuitry 544 to the UL front end 572. The UL front end 572 may include circuitry for transmitting wireless signals via the antenna 336. Thus, when the cellular communication circuitry 330 receives an instruction to transmit according to a first RAT (e.g., supported via the first modem 510), the switch 570 may be switched to a first state that enables the first modem 510 to transmit signals according to the first RAT (e.g., via a transmit chain including the transmit circuitry 534 and the UL front end 572). Similarly, when the cellular communication circuitry 330 receives an instruction to transmit according to a second RAT (e.g., supported via the second modem 520), the switch 570 may be switched to a second state, which enables the second modem 520 to transmit signals according to the second RAT (e.g., via a transmit chain including the transmit circuitry 544 and the UL front end 572).

[0072] As described herein, the first modem 510 and / or the second modem 520 may include hardware and software components for implementing various features and techniques described herein. The processors 512, 522 may be configured to implement some or all of the features described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively (or in addition), the processors 512, 522 may be configured as programmable hardware elements such as FPGAs (field programmable gate arrays) or as ASICs (application-specific integrated circuits). Alternatively (or in addition), the processors 512, 522 may be configured to implement some or all of the features described herein in conjunction with one or more of the other components 530, 532, 534, 540, 542, 544, 550, 570, 572, 335, and 336.

[0073] Additionally, as described herein, processors 512, 522 may include one or more processing elements. Thus, processors 512, 522 may include one or more integrated circuits (ICs) configured to perform the functions of processors 512, 522. Additionally, each integrated circuit may include circuitry (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of processors 512, 522.

[0074] In some aspects, the cellular communication circuitry 330 may include only one transmit / receive chain. For example, the cellular communication circuitry 330 may not include the modem 520, the RF front end 540, the DL front end 560, and / or the antenna 335b. As another example, the cellular communication circuitry 330 may not include the modem 510, the RF front end 530, the DL front end 550, and / or the antenna 335a. In some aspects, the cellular communication circuitry 330 may also not include the switch 570, and the RF front end 530 or the RF front end 540 may communicate, for example, directly, with, for example, the UL front end 572.

[0075] Network Element Examples

[0076] FIG. 6 illustrates an example block diagram of a network element 600, according to some aspects. According to some aspects, the network element 600 may implement one or more logical functions / entities of a cellular core network, such as a mobility management entity (MME), a serving gateway (S-GW), an access and management function (AMF), a session management function (SMF), a network slice quota management (NSQM), etc. It should be noted that the network element 600 of FIG. 6 is merely one example of a possible network element 600. As shown, the core network element 600 may include a processor(s) 604, which may execute program instructions for the core network element 600. The processor(s) 604 may also be coupled to a memory management unit (MMU) 640, which may be configured to receive addresses from the processor(s) 604 and translate those addresses into locations in memory (e.g., memory 660 and read-only memory (ROM) 650) or other circuits or devices.

[0077] Network element 600 may include at least one network port 670. Network port 670 may be configured to couple to one or more base stations and / or other cellular network entities and / or devices. Network element 600 may communicate with base stations (e.g., eNB / gNB) and / or other network entities / devices using any of a variety of communication protocols and / or interfaces.

[0078] As described further herein, the network element 600 may include hardware and software components for performing and / or supporting the performance of the functions described herein. The processor(s) 604 of the core network element 600 may be configured to perform or support the performance of 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). Alternatively, the processor 604 may be configured as a programmable hardware element, such as a field programmable gate array (FPGA), or as an application specific integrated circuit (ASIC), or as a combination thereof.

[0079] Radio Resource Control (RRC) idle and inactive states

[0080] Several cellular communication technologies include the use of radio resource control (RRC) protocols, which may facilitate, for example, connection establishment and release, radio bearer establishment, reconfiguration, and release, and / or various other possible signaling functions supporting the air interface between a wireless device and a cellular base station.

[0081] A wireless device may typically operate in one of several possible states with respect to RRC. For example, in LTE, a wireless device may operate in an RRC_CONNECTED state (e.g., in which the wireless device is capable of performing continuous data transfer, handovers between cells are managed by the network, and access stratum (AS) context information is maintained for the wireless device), or an RRC_IDLE state (e.g., in which the wireless device is capable of operating in a more battery efficient state when not performing continuous data transfer, the wireless device is capable of processing its cell reselection activity, and the network may not maintain AS context information for the wireless device).

[0082] According to at least some aspects, in addition to the RRC_CONNECTED and RRC_IDLE states, it may also be possible to support one or more other types of RRC states for a wireless device. For example, in NR, an RRC_INACTIVE state may be supported, in which the wireless device can operate in a relatively battery-efficient manner while the network also retains at least some AS context information. In some aspects, the wireless device may maintain a non-access stratum connection (NAS) using the CN and RRC configuration, as it did before the UE entered the inactive state.

[0083] In certain cases, a UE in an inactive state may not be allocated dedicated AS resources. According to at least some aspects, such a state may employ wireless device-based mobility, e.g., allowing a wireless device to move within a Radio Access Network Notification Area (RNA) without notifying the NG Radio Access Network (RAN). While in this state, the wireless device may perform cell reselection and system information acquisition on its own. At the same time, the last serving base station (e.g., gNB) may retain the wireless device's context and NG connection with the 5G Core Network (CN) associated with the wireless device, e.g., to more easily transition back to the RRC_CONNECTED state. When paging a wireless device in the RRC_INACTIVE state, RNA-specific parameters, including, e.g., a UE-specific DRX and a UE identifier index value (e.g., I-RNTI), may be used by the RAN.

[0084] A wireless device operating in such an RRC_INACTIVE state may perform RNA updates periodically (e.g., based on a configured periodic RNA update timer) and / or, according to some aspects, may perform RNA updates in an event-based manner, for example, when the wireless device moves from a currently configured RNA to a different RNA.

[0085] Use of the RRC_INACTIVE state may, at least in some cases, help reduce network signaling overhead for a wireless device's connection. For example, for a wireless device with infrequent data transmissions, utilizing such an RRC_INACTIVE state may reduce the amount of mobility-related signaling required (e.g., for handover) compared to the RRC_CONNECTED state, for example, because the wireless device may be able to manage its own cell reselection process as it moves between cells. For such a wireless device, utilizing the RRC_INACTIVE state may also reduce the amount of connection setup-related signaling required compared to the RRC_IDLE state, for example, because the network may retain at least some context information for the wireless device. This may directly reduce the signaling latency associated with transitioning to the RRC_CONNECTED state.

[0086] Another potential benefit is that such a state may reduce control plane delays for the wireless device, as compared to operating in, for example, the RRC_IDLE state. For example, the RRC_INACTIVE state may allow for a reduced access stratum connection setup period and / or a reduced non-access stratum connection setup period as compared to the RRC_IDLE state. Thus, the time from a battery-efficient state to the start of continuous data transfer may be reduced.

[0087] Furthermore, such a state may improve the power conservation capabilities of the wireless device, for example, as compared to operating in the RRC_CONNECTED state. For example, while in the RRC_CONNECTED state, measurements of the serving cell and / or neighboring cells may be required more frequently than while in the RRC_INACTIVE state, for example, to coincide at least with the connected mode discontinuous reception (C-DRX) period of the wireless device.

[0088] A wireless device may manage cell reselection while in the RRC_INACTIVE state. The goal of the cell reselection process is to camp on a suitable cell, which is a cell that has sufficient signal strength, signal quality, and / or other characteristics, so that the wireless device can establish / activate a connection and transfer data through that cell. Cell reselection may include either or both intra-frequency cell reselection or inter-frequency cell reselection. As part of such a cell reselection process while in the RRC_INACTIVE state, the wireless device may perform cell measurements on the serving cell and / or neighboring cells. The manner in which such cell measurements are performed can significantly impact wireless device power consumption and the amount of time required to access continuous data transfer capability (e.g., by resuming operation in the RRC_CONNECTED state). For example, if synchronization signal blocks (SSBs) are used to perform cell measurements, there may be a delay between the wireless device's inactive state wake-up phase and the next SSB burst, and / or the measurements may be performed over a relatively long period to allow receiver beam sweeping across multiple SSB bursts. Furthermore, such SSB bursts may be performed at a different frequency and / or at a wider bandwidth than the wireless device's designated inactive state wake-up phase. Alternatively, the cellular base station may provide a paging phase that is aligned in time and / or frequency with the SSB, e.g., to facilitate reducing wireless device power consumption in the RRC inactive state.

[0089] 7, a communication flow diagram illustrating a communication flow 700 for entering and resuming from an RRC_INACTIVE state according to an aspect of the present disclosure is shown. Aspects of the communication flow may be implemented by a wireless device, in conjunction with one or more radio nodes and one or more portions of a core network (CN), such as the UE 702, gNB 704, final serving gNB 706, and Access and Mobility Functions (AMF) 708 shown in and described with respect to FIG. 7, or more generally, in conjunction with any of the computer circuits, systems, devices, elements, or components shown in the above figures, among others, as appropriate. For example, the processor (and / or other hardware) of such a device may be configured to cause the device to perform any combination of the method elements shown in the figure and / or other method elements.

[0090] In communication flow 700, a wireless node, such as a UE 702, receives an RRC release message from, for example, a final serving gNB 706 (step 1). The RRC release message may include pending configuration information for the UE 702 to enter an RRC inactive state. The pending configuration information may include information for operating in and / or resuming a connection from an RRC inactive state, such as information about the RNA, and security parameters for supporting encrypted resume messages, such as a UE identifier and resume security information. In some aspects disclosed herein, the gNB may also provide resource information for receiving CSI-RS / TRS via the RRC release message with the pending configuration information (described in further detail below). The RNA may include an area associated with a set of gNBs within which the UE is permitted to move without the need to notify the network.

[0091] In certain cases, the UE 702 may desire to perform dedicated data transmission / reception that cannot be performed in the inactive state. To exit the inactive state, the UE 702 may initiate an RRC resumption procedure by sending an RRC resumption request to a gNB, which in this example is a gNB 704 different from the last serving gNB 706 (step 2). The RRC resumption request may include, for example, a UE identifier and resumption security information. The gNB 704 may then retrieve the UE 702's context from the last serving gNB (step 3). After receiving the UE context (step 4), the gNB 704 may send an RRC resumption message to the UE 702 in response to the RRC resumption request (step 5). The UE 702 may then transition to the RRC connected state 710 and send an RRC resumption complete message to the gNB 704 (step 6).

[0092] The gNB 704 then performs the UE handover from the final serving gNB 706 by sending a data forwarding address indication to the final serving gNB (step 7) and sending a path switch request to the AMF 708 (step 8). The AMF 708 responds with a path switch request response (step 9), and the gNB sends a UE context release to the final serving gNB 706 (step 10).

[0093] In certain wireless communication networks, encryption may be used to help provide data integrity and security. For example, in 5G NR, user data in a data radio bearer (DRB) block may be encrypted to provide data confidentiality and integrity protection for the user data. In addition, RRC signaling in a signaling radio bearer (SRB) block may be encrypted separately from the user data to help provide signaling data confidentiality and wireless network integrity. Thus, keys used for NAS level security between the CN and wireless devices are cryptographically separate from AS keys used in, for example, RRC signaling.

[0094] Improved paging procedures in 5G / NR

[0095] The paging procedure in 5G / NR allows a UE to reside in the system in a reduced power state, such as the aforementioned RRC_IDLE or RRC_INACTIVE state. The UE can listen for paging messages while in RRC_IDLE or RRC_INACTIVE state. The paging messages allow the network to initiate a mobile-terminated connection. The CN is responsible for the RRC_IDLE paging procedure, while the serving base station (e.g., gNB) is responsible for the RRC_INACTIVE paging procedure. The paging message is the same for both CN-initiated paging (i.e., paging for a UE in RRC_IDLE state) and RAN-initiated paging (i.e., paging for a UE in RRC_INACTIVE state). It will be appreciated that in some implementations, the techniques described herein may be applied equally to both RRC_IDLE and RRC_INACITVE UEs, while in other implementations the network may choose to implement the techniques differently for different UEs in reduced power states (e.g., enabling a particular technique for use by UEs in RRC_INACTIVE state but not enabling that particular technique for UEs in RRC_IDLE state).

[0096] While UE-specific paging is available, e.g., to indicate the arrival of an incoming call, additional categories of paging information are also available when all UEs in the RNA need to be notified of changes in system information or the arrival of an Earthquake and Tsunami Warning System (ETWS) / Commercial Mobile Alert Service (CMAS) message. In such cases, the payload of the PDCCH may be used for the paging procedure. Specifically, the Downlink Control Information (DCI) format 1_0 may contain a "short message" if the cyclic redundancy check (CRC) bits are scrambled using the Paging-Radio Network Temporary Identifier (P-RNTI). The short message may be used to indicate that system information has been updated and needs to be reacquired or that there is an incoming ETWS / CMAS message.

[0097] For a UE in the RRC_IDLE state, the Access and Mobility Management Function (AMF) maintains a record of the UE's location and is used to perform paging procedures for the UE. Specifically, a UE in the RRC_IDLE (or RRC_INACTIVE) state is configured with a discontinuous reception (DRX) cycle T (in terms of the number of frames) for paging interception. That is, the UE receiver enters "sleep" mode during periodic paging occasions (POs). The UE then determines the paging frame (PF) from among the T frames within the DRX cycle. Within the PF, the UE determines the PO. The UE may determine the PO using a combination of information broadcast in System Information Block 1 (SIB1) and the assigned 5G SAE Temporary Mobile Subscriber Identity (5G-S-TMSI). At each PO, the UE may scan for PDCCH transmissions with a CRC scrambled by the P-RNTI to determine whether paging information is present in the PDSCH.

[0098] There may be S PDCCH interception occasions within a PO, where each S interception occasion corresponds to one synchronization signal block (SSB). The UE may intercept all PDCCH interception occasions transmitted via different beams to intercept paging messages (assuming that the same paging message and short message are repeated in all transmission beams or interception occasions).

[0099] As mentioned above, the UE may overhear DCI format 1_0 with CRC bits scrambled using the P-RNTI. When DCI format 1_0 is detected, the UE may read the short message indicator field. If the short message indicator indicates the presence of a paging message, the UE may decode the associated PDSCH (note that a UE-specific pagingRecordList is carried by the PDSCH). If the UE finds its own UE_ID in the PagingRecordList, the UE initiates a random access channel (RACH) procedure to make an RRC connection (or reconnection). Otherwise, the UE may remain in RRC_IDLE or RRC_INACTIVE state.

[0100] As mentioned above, a UE in RRC_IDLE mode and / or RRC_INACTIVE mode enters a "sleep" state between two consecutive POs to save power. However, to receive a paging message, the UE must wake up and perform preparation, including, for example, automatic gain control (AGC), time / frequency offset estimation / adjustment, etc. These operations require acquiring a known signal from the network that is transmitted close to the UE's listening occasion. In LTE, there was a cell reference signal (CRS) transmitted in every subframe, so the UE could use the CRS for preparation. However, there is no CRS in 5G / NR. Therefore, NR UEs use single signal bits (SSBs). SSBs are transmitted periodically, but less frequently than every frame or subframe.

[0101] As can be seen, an NR UE that relies on an SSB for preparation must wake up and then listen for the SSB. However, because the SSB and PO are not aligned, the UE often must wake up earlier than necessary to receive the SSB. After performing AGC, time / frequency offset estimation / adjustment, etc., the UE must remain awake until the PO arrives. As described in more detail below and illustrated with reference to FIG. 8, this can significantly increase the power / energy consumption of an NR UE.

[0102] 8, an exemplary UE power consumption graph 800 is shown, plotting UE power consumption on a vertical axis 804 against time on a horizontal axis 802 while the UE is waiting for a paging occasion (PO). As discussed above, the UE's power consumption begins to ramp up (810) toward maximum power (812) in preparation for listening to the SSB (806). Once the SSB is listened to, the UE may remain in a "wake-up" state (814) waiting for the next PO (808), at which point it may ramp up toward maximum power (816) to listen to the next PO (808) before returning to an idle or inactive state (818).

[0103] Referring now to FIG. 9 , an exemplary improved UE power consumption graph 900 is shown, plotting UE power consumption on a vertical axis 904 against time on a horizontal axis 902 while the UE is waiting for a paging occasion (PO). Typically, an NR UE in an RRC_CONNECTED state may be configured to receive CSI-RS / TRS information for channel tracking, time-frequency synchronization, mobility, etc. However, such CSI-RS and TRS information is currently configurable only when the UE is in an RRC_CONNECTED state. From the UE's perspective, the CSI-RS or TRS configuration information is UE-specific. However, from the network's perspective, multiple UEs may be configured with the same CSI-RS and TRS information to eavesdrop on the network. This shared configuration between CRS-RS and TRS may allow the network to reduce the resource overhead used for CSI-RS and TRS.

[0104] Advantageously, CSI-RS and TRS can also be shared with UEs in RRC_IDLE and / or RRC_INACTIVE states to help them prepare for paging reception. Specifically, if there is configured CSI-RS and TRS information transmitted close to a UE's PO, the UE can also use these CSI-RS / TRS readings to perform AGC, time / frequency synchronization, etc., to synchronize and prepare for the next PO.

[0105] Returning to Figure 9, the UE's power consumption begins to ramp up (910) towards maximum power (912) in preparation for listening to the CSI-RS / TRS (906). Because the CSI-RS / TRS (906) is closer in time to the UE's PO (908), the UE needs to remain in the "wake up" state (912) for a shorter period of time before being able to return (914) to a reduced power (e.g., idle or inactive) state, thereby saving UE power compared to the scenario shown in Figure 8.

[0106] As mentioned above, a UE in RRC_IDLE and RRC_INACTIVE states does not have a valid RRC configuration, which means that any CSI-RS / TRS resource information received by the UE while in a previous RRC_CONNECTED state is no longer valid when the UE is in RRC_IDLE or RRC_INACTIVE states. Therefore, it would be advantageous to provide a new mechanism by which the network can inform a UE in RRC_IDLE and RRC_INACTIVE states which CSI-RS / TRS resources it should listen on.

[0107] In a first aspect, new CSI-RS / TRS resource information for UEs in RRC_IDLE and RRC_INACTIVE states may be carried in a new type of SIB (also referred to herein as "SIB-x" to avoid confusion with existing SIBs in NR). The new SIB-x can be transmitted periodically by the network to inform UEs in RRC_IDLE and RRC_INACTIVE states of available CSI-RS / TRS resource information using newly defined information elements (IEs), which are described in more detail below.

[0108] In a 5G / NR implementation, types of CSI-RS information that may be made available to a UE in RRC_CONNECTED state include non-zero power (NZP) CSI-RS (TRS), which may be used, for example, for CSI reporting, RLF, BM, mobility, and time / frequency tracking; CSI-Interference Measurement (CSI-IM), which may be used, for example, to measure interference from neighboring cells (while nothing is transmitted from the serving cell itself); and zero power (ZP) CSI-RS, which may be used, for example, to perform resource reservation and rate matching.

[0109] In some implementations of the first aspect, types of CSI-RS that may also be used for UEs in reduced power states such as RRC_INACTIVE or RRC_IDLE include NZP CSI-RS (which may also be used if configured) and TRS (which is always configured for the UE).

[0110] An information element, or "IE," in 5G / NR refers to a parameter that can be set to a specified value. An IE should be introduced when there are multiple fields for which the same value set applies. IEs may also be defined for other reasons, such as to subdivide the definition of a particular system element. Groups of closely related IE type definitions may preferably be placed together, for example, in a common ASN.1 section.

[0111] CSI-RS related IEs for a UE in RRC_CONNECTED state include: CSI-MeasConfig (which may include one or more CSI-ResourceConfigs), CSI-ResourceConfig (which may include one or more of CSI-ResourceSets), NZP-CSI-RS-ResourceSet (which may include one or more of NZP-CSI-RS-Resources), and NZP-CSI-RS-Resources. According to some implementations of the first aspect (or other aspects disclosed herein), a new IE (and a new IE structure) may be introduced for UEs in a reduced power state, such as RRC_IDLE or RRC_INACTIVE. Such a new IE structure, also referred to herein as "NZP-CSI-ResourceConfig-IdleUE IE," may advantageously be based at least in part on an existing IE structure for UEs in RRC_CONNECTED state.

[0112] 10 , illustrated is an example NZP-CSI-ResourceConfig-IdleUE IE structure 1000 to be used for a UE in RRC_IDLE or RRC_INACTIVE state, in accordance with some aspects. As shown in FIG. 10 , in some implementations, the new IE structure may include new IEs NZP-CSI-ResourceConfig-IdleUE 1002 (which may include a list of NZP-CSI-RS-ResourceSet-IdleUEs), NZP-CSI-RS-ResourceSet-IdleUE 1004 (which may include a list of NZP-CSI-RS-Resource-IdleUEs), and NZP-CSI-RS-Resource-IdleUE 1006 (which may indicate CSI-RS resources).

[0113] As will be understood herein, the NZP-CSI-RS-ResourceSet-IdleUE for a UE in RRC_INACTIVE / RRC_IDLE mode corresponds to the NZP-CSI-RS-ResourceSet currently being used by a UE in RRC_CONNECTED mode, and the NZP-CSI-RS-Resource-IdleUE for a UE in RRC_INACTIVE / RRC_IDLE mode corresponds to the NZP-CSI-RS-Resource currently being used by a UE in RRC_CONNECTED mode.

[0114] 11 , an example use of different NZP-CSI-ResourceConfig-IdleUE IEs for multiple UEs in RRC_IDLE or RRC_INACTIVE states corresponding to different NZP-CSI-RS-ResourceSets from different UEs in RRC_CONNECTED mode, according to some aspects, is shown in 1100. Element 1110 of FIG. 11 refers to an R15 / R16 UE (referred to as "UE1" in this example) in RRC_CONNECTED mode, and element 1120 refers to another R15 / R16 UE (referred to as "UE2" in this example) in RRC_CONNECTED mode. Element 1110 is defined by a CSI-ResourceConfig (1112), which includes a list of NZP-CSI-RS-ResourceSets (1114), each of which may also include a list of NZP-CSI-RS-Resources (1116). Similarly, element 1120 is defined by a CSI-ResourceConfig (1122), which contains a list of NZP-CSI-RS-ResourceSets (1124), each of which may also contain a list of NZP-CSI-RS-Resources (1126).

[0115] As shown by arrow 1118 in Figure 11, the NZP-CSI-RS-ResourceSet 1114 from UE1 (1110) may be stored as an NZP-CSI-RS-ResourceSet-IdleUE 1004 (which may include a list of NZP-CSI-RS-Resource-IdleUE 1006, as described above). Similarly, as shown by arrows 1128 and 1130 in Figure 11, the NZP-CSI-RS-ResourceSets 1124 from UE2 (1120) may be stored as an additional NZP-CSI-RS-ResourceSet-IdleUE IE 1004 to be used for UEs in RRC_IDLE or RRC_INACTIVE state (e.g., Rel-17 and later UEs) within the exemplary NZP-CSI-ResourceConfig-IdleUE IE structure 1000.

[0116] Here, various parameters that may be included in the three IEs NZP-CSI-ResourceConfig-IdleUE, NZP-CSI-RS-ResourceSet-IdleUE, and NZP-CSI-RS-Resource-IdleUE will be described.

[0117] First, the NZP-CSI-ResourceConfig-IdleUE IE may include the nzp-CSI-RS-ResourceSets parameter. This parameter may also include a list of CSI-RS-ResourceSet-IdleUEs. Since the NZP-CSI-RS-ResourceSet IE can only have one period, including multiple NZP-CSI-RS-ResourceSet IEs should allow compatibility with current NR schemes. Different UEs in RRC_IDLE mode may have different DRX cycles and offsets, and therefore should be able to indicate multiple CSI-RS-ResourceSets to help them find a CSI-RS that is close in time to their own PO.

[0118] Second, the NZP-CSI-RS-ResourceSet-IdleUE IE may include the following parameters: nzp-CSI-RS-ResourcesSet-IdleUE-ID (i.e., the ID of the resource set), nzp-CSI-RS-Resources-IdleUE (i.e., one or more of the non-zero power CSI-RS resources), repetition (i.e., an indication of whether the same spatial filter is used for transmission of CSI-RS in a CSI-RS-Resource in the CSI-RS-ResourceSet; the value of this parameter may be the same as that in the corresponding NZP-CSI-RS-ResourceSet for the UE in RRC_CONNECTED mode), and TRS-info (a field that may be set to 'TRUE' if the NZP-CSI-RS is for TRS).

[0119] Third, the NZP-CSI-RS-Resource-IdleUE IE contains the following parameters (which are a subset of the parameters of the existing NZP-CSI-RS-Resource structure): nzp-CSI-RS-ResourceID (i.e., the ID of the CSI-RS resource), resourceMapping (i.e., a field specifying the time / frequency mapping of the CSI-RS to resource elements), powerControlOffset (i.e., a field specifying the power difference between the CSI-RS and the PDSCH), and powerControlOffsetSS (i.e., a field specifying the power difference between the CSI-RS and the Secondary Synchronization Signal (SS)). scramblingID (i.e., input for generating the pseudo-random sequence), periodicityAndOffset (i.e., specifies the periodicity and offset of the CSI-RS), and qcl-InfoPeriodicCSI-RS (i.e., specifies the quasi-co-location (QCL) information of the CSI-RS). (In NR, two antenna ports are said to be quasi-co-located if the attributes of the channel on which symbols on one antenna port are carried can be inferred from the channel on which symbols on the other antenna port are carried.)

[0120] Regarding the QCL indication (e.g., using the qcl-InfoPeriodicCSI-RS IE) for a UE in RRC_IDLE mode, note that a UE in RRC_IDLE mode does not have a transmission configuration indication (TCI) state. Thus, for a UE in RRC_IDLE mode, the interpretation of qcl-InfoPeriodicCSI-RS may not be the same as for a UE in RRC_CONNECTED state. Instead, the qcl-InfoPeriodicCSI-RS parameter of the original CSI-RS resource of a UE in RRC_CONNECTED mode may be used to refer to either another CSI-RS resource or SSB configured (e.g., by being QCL'd) for a UE in RRC_CONNECTED mode. Thus, because the QCL'd CSI-RS information is only available to UE(s) in RRC_CONNECTED mode, the qcl-InfoPeriodicCSI-RS for a UE in RRC_IDLE mode cannot be QCL'd with other CSI-RS. However, because a UE in RRC_IDLE mode knows the correct SSB location and the receiving beam to use, it is permissible to QCL the qcl-InfoPeriodicCSI-RS with the SSB. This implies that only CSI-RS resources for a UE in RRC_CONNECTED mode that are QCL'd with the SSB may be used for a UE in RRC_IDLE mode. Thus, according to some implementations of the first aspect (and other aspects disclosed herein), the CSI-RS resource indication for a UE in RRC_IDLE mode includes QCL information for only the SSB.

[0121] 12, an additional technique 1200 for performing QCL indication for a UE in RRC_IDLE or RRC_INACTIVE mode is illustrated, in accordance with some aspects. FIG. 12 illustrates an example NZP-CSI-RS-ResourceSet-IdleUE structure (1202), which includes a list of NZP-CSI-RS-ResourceIdleUE structures (1204A-1204D), each of which may include a qcl-InfoPeriodicCSI-RS IE 1206. According to some approaches for QCL indication (i.e., using the qcl-InfoPeriodicCSI-RS IE 1206), CSI-RS resources used by a UE in RRC_CONNECTED mode are included if they are (1) QCLed with an SSB (e.g., as shown between SSB1 (12081) and NZP-CSI-RS-Resource-IdleUE 1204A, or between SSB2 (12082) and NZP-CSI-RS-Resource-IdleUE 1204B), (2) QCLed with one of the CSI-RS Resources indicated for a UE in RRC_IDLE mode (e.g., as shown between NZP-CSI-RS-Resource-IdleUE 1204B and NZP-CSI-RS-Resource-IdleUE 1204C), or (3) not QCLed with anything, i.e., qcl-InfoPeriodicCSI-RS When the IE field NZP-CSI-RS-Resource-IdleUE is not included (as shown in 1210).

[0122] As mentioned above, preferably, there is some form of message delivery mechanism for UEs in RRC_IDLE and RRC_INACTIVE modes. Specifically, UEs in RRC_IDLE or RRC_INACTIVE modes may need to receive system information (SI) to obtain parameters necessary for cell (re)selection and paging reception. Currently, nine SIBs (i.e., SIB1 to SIB9) are defined in NR and are carried by system information RRC messages. Therefore, according to various implementations proposed herein, a new SIB (also referred to herein as "SIB-x") may be used to indicate CSI-RS resource sets for UEs in RRC_IDLE mode and UEs in RRC_INACTIVE mode. As described in detail above, the aforementioned SIB-x may include an NZP-CSI-ResourceConfig-IdleUE IE to support notification of available CSI-RS resource sets for UEs in RRC_IDLE and RRC_INACTIVE modes.

[0123] Various techniques are available for the SIB transmission mechanism in such a scheme. For example, in one implementation, a new SIB-x may be transmitted periodically (in which case, for example, SIB1 may be used to indicate the periodicity of the transmission of the new SIB-x). Alternatively, in another implementation, a new SIB-x may be transmitted "on-demand." For example, to request a SIB-x transmission, the UE may transmit an assigned preamble to the network. SIB1 may also be used to indicate which RACH configuration can be used (for example, in the RACH process, either MGS1 or MSG3 may be used as a request to transmit a new SIB-x to the UE).

[0124] In a second aspect, the SIB-x may be configured to carry one of a set of predefined CSI-RS / TRS resource information configurations. This approach has the advantage of reducing signaling overhead, since the TRS resource indication can be selected only from among the predefined TRS resource configurations. For example, there may be N sets (e.g., N=16) of possible predefined configurations, which may include some (or all) of the following elements: (1) TRS period, (2) TRS slot offset, (3) TRS starting symbol index, (4) TRS bandwidth (if this parameter is not indicated, the TRS may take the full bandwidth), and (5) TRS comb offset.

[0125] According to a second aspect, log2(N) bits may be used within the SIB to indicate the TRS configuration. The QCL for the TRS may be the same as the corresponding SIB (or corresponding SSB), and the TRS sequence may be generated based on the cell ID or other specified ID value. As an alternative delivery mechanism for carrying predefined TRS resource information, instead of the SIB, the PDSCH itself carrying the paging message may be used to carry the medium access control (MAC) control element (CE), which can enable or disable TRS according to the needs of the system.

[0126] In a third aspect, the PDSCH carrying the paging message can also be used to carry CSI-RS / TRS resource information, which can potentially be used by UEs to listen to the same PO in multiple upcoming PFs. Specifically, the PDSCH carrying the paging message can also be used to carry the NZP-CSI-ResourceConfig-IdleUE structure as described above. Because the PDSCH allocation is flexible, its size can be increased as needed to carry CSI-RS / TRS resource information. In some cases, only relevant CSI-RS / TRS resource information (e.g., that which is close in time to the PO) is actually included in the PDSCH. Another potential advantage of this third aspect is that different UEs with different POs will see different NZP-CSI-Resource-IdleUE structures. Thus, according to the third aspect, the NZP-CSI-ResourceConfig for UEs in RRC_IDLE mode can be included in the PDSCH carrying the paging message.

[0127] In the fourth aspect, the PDCCH may also or alternatively be used to carry CSI-RS / TRS resource information, for example, along with P-RNTI information, which may be used by a UE to listen to the same PO in multiple upcoming PFs. This fourth aspect is similar to the third aspect described above, except that the CSI-RS / TRS information for paging message scheduling may be carried directly in the PDCCH rather than the PDSCH. In some implementations of the fourth aspect, the information with the P-RNTI carried in the PDCCH may be an index of a predefined CSI-RS / TRS pattern or an index of a pattern provided in the SIB. In this context, examples of the pattern may refer to the periodicity and / or frequency spreading of the CSI-RS / TRS.

[0128] 13 , illustrated is a technique 1300 for using a PDSCH to convey CSI-RS / TRS resource information according to some aspects. At block 1302, a UE may overhear DCI format 1_0 with CRC bits scrambled using the P-RNTI in a first PO (labeled PO1). If DCI format 1_0 is detected, the UE may read a short message indicator field. If the short message indicator indicates the presence of a paging message, the UE may decode an associated PDSCH to obtain an NZP-CSI-ResourceConfig-IdleUE at block 1304. As described above, the NZP-CSI-ResourceConfig-IdleUE may be used to convey one or more sets of CSI-RS / TRS resource information to a UE in RRC_IDLE mode.

[0129] The CSI-RS / TRS information obtained by the UE (represented by block 1308) may then be used for synchronization and paging reception at the next PO (time progression is represented by arrow 1306, and the next PO is labeled PO2 in block 1310). Finally, in block 1312, the UE may obtain the actual paging message from the PDSCH. As mentioned above, different UEs with different POs will see different NZP-CSI-Resources-IdleUE.

[0130] It will be appreciated that one or more of the first through fourth aspects described above may be combined in a given implementation, and that the various aspects are not necessarily mutually exclusive. For example, some networks may adopt new predefined configurations over time and / or allow for customization or configuration of the mode used to transmit CSI-RS / TRS resource information to UEs in RRC_IDLE or RRC_INACTIVE mode.

[0131] It will also be appreciated that according to each of the above first to fourth aspects, the UE may perform measurements on the CSI-RS / TRS and then take the measurements (e.g. Reference Signal Received Power (RSRP) / Reference Signal Received Quality (RSRQ) measurements) into account for cell quality assessment, i.e., cell selection and / or reselection purposes.

[0132] Referring now to FIG. 14 , an example flowchart 1400 is shown for receiving CSI-RS and TRS resource information by a UE in a reduced power state, such as RRC_IDLE mode or RRC_INACTIVE mode, in accordance with some aspects. First, at step 1402, the method may receive, by a user device (e.g., a 5G / NR UE) in a reduced power state, resource information for receiving channel state information reference signals (CSI-RS) and tracking reference signals (TRS) (e.g., based on predefined TRS resource information, as described above with respect to the second aspect). Next, at step 1404, the user device may exit the reduced power state (e.g., RRC_INACTIVE state or RRC_IDLE state) to receive CSI-RS and TRS based on the received resource information. Next, at step 1406, the user device may synchronize with the base station based on the CSI-RS and TRS to receive downlink control information messages. Next, at step 1408, the user device may receive paging information within a first PDSCH transmission based on the received downlink control information message. The user device may then determine whether paging information is present in the first PDSCH transmission for this user device in step 1410. The user device may then initiate a RACH procedure to make an RRC connection to the base station based on the determination that paging information is present for this user device in step 1412, or may return to a reduced power state based on the determination that there is no paging information for this user device in step 1414.

[0133] 15, an example flowchart of various methods for a user device to receive CSI-RS and TRS resource information while in a reduced power state, such as RRC_IDLE or RRC_INACTIVE mode, at step 1402, according to some aspects is shown. At block 1502, the user device is presented with an option to receive a base station-transmitted SIB, where the SIB includes resource information for receiving CSI-RS and TRS. At block 1504, the user device is presented with another option to receive a base station-transmitted PDSCH message (e.g., a PDSCH message transmitted before the PDSCH message referenced at step 1408), where the other PDSCH message includes resource information for receiving CSI-RS and TRS. At block 1506, a further selected user device is presented with a base station-transmitted PDCCH message, where the PDCCH message includes resource information for receiving CSI-RS and TRS. As can be appreciated, one or more of the various options described with reference to FIG. 15 may be used at different times and / or according to different settings in a given wireless communication system.

[0134] 16, an example flowchart 1600 is shown for transmitting CSI-RS and TRS resource information from a base station to a UE in a reduced power state, such as RRC_IDLE mode or RRC_INACTIVE mode, in accordance with some aspects. Beginning at step 1602, the method may involve transmitting, by a base station (e.g., a gNB), resource information for receiving channel state information reference signals (CSI-RS) and tracking reference signals (TRS) to a user device (e.g., a 5G / NR UE) in a reduced power state (e.g., based on predefined TRS resource information). Next, at step 1604, the method may involve using the base station to transmit CSI-RS and TRS to a user device that has exited the reduced power state based on the transmitted resource information. Next, at step 1606, the base station may determine whether paging information is present in a first physical downlink shared channel (PDSCH) transmission for the user device. Next, in step 1608, the base station may transmit a downlink control information message, where the downlink control information message is based on the determination that paging information is present for the user device that is synchronized with the base station. Finally, in step 1610, the base station may transmit a first PDSCH transmission based on the determination that paging information is present for the user device.

[0135] 17, an example flowchart of various methods for a base station to transmit CSI-RS and TRS resource information to a UE in a reduced power state, such as an RRC_IDLE mode or an RRC_INACTIVE mode, in step 1602, according to some aspects is shown. At block 1702, an option for transmitting an SIB is presented to the base station, where the SIB includes resource information for receiving CSI-RS and TRS by a user device. At block 1704, another option for transmitting another PDSCH message (e.g., a PDSCH message transmitted before the PDSCH message referenced in step 1606), where the another PDSCH message includes resource information for receiving CSI-RS and TRS by a user device, is presented to the base station. At block 1706, yet another option for transmitting a PDCCH message is presented to the base station, where the PDCCH message includes resource information for receiving CSI-RS and TRS by a user device. As can be appreciated, one or more of the various options described with reference to FIG. 17 may be used at different times and / or according to different settings in a given wireless communication system.

[0136] Example

[0137] Further examples are provided in the following sections.

[0138] According to Example 1, a method for paging in a wireless system is disclosed, the method including: receiving, by a user device in a reduced power state, resource information for receiving a channel state information reference signal (CSI-RS) and a tracking reference signal (TRS); exiting, by the user device, from the reduced power state to receive the CSI-RS and the TRS based on the resource information; synchronizing, by the user device, with a base station to receive a downlink control information message based on the received CSI-RS and TRS; receiving, by the user device, paging information in a first physical downlink shared channel (PDSCH) transmission based on the received downlink control information message; determining, by the user device, whether paging information is present in the first physical downlink PDSCH transmission for the user device; initiating, by the user device, a random access channel (RACH) procedure to create a radio resource control (RRC) connection based on the determination that paging information is present for the user device; and returning the user device to the reduced power state based on the determination that paging information is not present for the user device.

[0139] Example 2 includes the subject matter of Example 1, wherein receiving resource information for receiving CSI-RS and TRS includes receiving, in a reduced power state, a system information block (SIB) transmitted by a base station, the SIB including resource information for receiving CSI-RS and TRS for a set of two or more user devices.

[0140] Example 3 includes the subject matter of example 2, further including receiving, by the user device, the SIB via periodic transmission.

[0141] Example 4 includes the subject matter of example 2, further including sending, by the user device, a request for the SIB.

[0142] Example 5 includes the subject matter of example 4, in which sending the request for the SIB includes sending a RACH preamble including the request, and the received CSI-RS and TRS are based on the request.

[0143] Example 6 includes the subject matter of example 1 or 2, wherein resource information for receiving CSI-RS and TRS is predefined.

[0144] Example 7 includes the subject matter of example 6, wherein resource information for receiving CSI-RS and TRS is predefined based on one or more sets of configuration information.

[0145] Example 8 includes the subject matter of Example 1, wherein receiving the resource information for receiving the CSI-RS and the TRS further includes receiving a second PDSCH message transmitted by the base station before the first PDSCH message, the second PDSCH message including the resource information for receiving the CSI-RS and the TRS.

[0146] Example 9 includes the subject matter of Example 1, and wherein receiving resource information for receiving CSI-RS and TRS further includes receiving a Physical Downlink Control Channel (PDCCH) message sent by the base station, the PDCCH message including the resource information for receiving CSI-RS and TRS.

[0147] Example 10 includes the subject matter of Example 9, in which the resource information included in the PDCCH message indicates a predefined CSI-RS and TRS pattern.

[0148] According to Example 11, a wireless device is disclosed, comprising an antenna, a radio operably coupled to the antenna, and a processor operably coupled to the radio, wherein the wireless device is configured to receive resource information for receiving a channel state information reference signal (CSI-RS) and a tracking reference signal (TRS) in a reduced power state, exit from the reduced power state to receive the CSI-RS and the TRS based on the resource information, synchronize with a base station to receive a downlink control information message based on the received CSI-RS and TRS, receive paging information in a first physical downlink shared channel (PDSCH) transmission based on the received downlink control information message, determine whether paging information is present in the first physical downlink PDSCH transmission for the wireless device, initiate a random access channel (RACH) procedure to create a radio resource control (RRC) connection based on the determination that paging information is present for the wireless device, and return to the reduced power state based on the determination that paging information is not present for the wireless device.

[0149] Example 12 includes the subject matter of Example 11, wherein receiving resource information for receiving CSI-RS and TRS includes receiving, in a reduced power state, a system information block (SIB) transmitted by a base station, the SIB including resource information for receiving CSI-RS and TRS for a set of two or more user devices.

[0150] Example 13 includes the subject matter of example 12, in which the wireless device is further configured to receive the SIB via periodic transmission.

[0151] Example 14 includes the subject matter of example 12, in which the wireless device is further configured to send a request for the SIB.

[0152] Example 15 includes the subject matter of Example 14, in which sending a request for an SIB includes sending a RACH preamble including the request, and the received CSI-RS and TRS are based on the request.

[0153] Example 16 includes the subject matter of Example 11 or 12, wherein the resource information for receiving the CSI-RS and the TRS is predefined.

[0154] Example 17 includes the subject matter of Example 16, wherein the resource information for receiving the CSI-RS and the TRS is predefined based on one or more sets of configuration information.

[0155] Example 18 includes the subject matter of Example 11, wherein receiving the resource information for receiving the CSI-RS and the TRS further includes receiving a second PDSCH message transmitted by the base station before the first PDSCH message, the second PDSCH message including the resource information for receiving the CSI-RS and the TRS.

[0156] Example 19 includes the subject matter of Example 11, and wherein receiving resource information for receiving CSI-RS and TRS further includes receiving a Physical Downlink Control Channel (PDCCH) message sent by the base station, the PDCCH message including the resource information for receiving CSI-RS and TRS.

[0157] Example 20 includes the subject matter of Example 19, in which the resource information included in the PDCCH message indicates a predefined CSI-RS and TRS pattern.

[0158] According to Example 21, an integrated circuit is disclosed, the integrated circuit including a circuit element configured to: cause a wireless device to receive resource information for receiving a channel state information reference signal (CSI-RS) and a tracking reference signal (TRS) in a reduced power state; cause the wireless device to exit the reduced power state to receive the CSI-RS and the TRS based on the resource information; cause the wireless device to synchronize with a base station to receive a downlink control information message based on the received CSI-RS and TRS; cause the wireless device to receive paging information in a first physical downlink shared channel (PDSCH) transmission based on the received downlink control information message; determine whether paging information is present in the first physical downlink PDSCH transmission for the wireless device; cause the wireless device to initiate a random access channel (RACH) procedure to create a radio resource control (RRC) connection based on a determination that paging information is present for the wireless device; and cause the wireless device to return to the reduced power state based on a determination that paging information is not present for the wireless device.

[0159] Example 22 includes the subject matter of Example 21, and wherein having the wireless device receive resource information for receiving CSI-RS and TRS includes having the wireless device in a reduced power state receive a system information block (SIB) transmitted by a base station, the SIB including resource information for receiving CSI-RS and TRS for a set of two or more user devices.

[0160] Example 23 includes the subject matter of Example 22, in which the circuit element is further configured to cause the wireless device to receive the SIB via periodic transmission.

[0161] Example 24 includes the subject matter of example 22, in which the circuit element is further configured to cause the wireless device to send a request for the SIB.

[0162] Example 25 includes the subject matter of Example 24, wherein transmitting a request for an SIB includes transmitting a RACH preamble including the request from the wireless device, and the received CSI-RS and TRS are based on the request.

[0163] Example 26 includes the subject matter of Example 21 or 22, wherein the resource information for receiving the CSI-RS and the TRS is predefined.

[0164] Example 27 includes the subject matter of Example 26, wherein the resource information for receiving the CSI-RS and TRS is predefined based on one or more sets of configuration information.

[0165] Example 28 includes the subject matter of Example 21, and wherein causing the wireless device to receive resource information for receiving CSI-RS and TRS further includes causing the wireless device to receive a second PDSCH message transmitted by the base station prior to the first PDSCH message, the second PDSCH message including resource information for receiving CSI-RS and TRS.

[0166] Example 29 includes the subject matter of Example 21, and wherein causing the wireless device to receive resource information for receiving CSI-RS and TRS further includes causing the wireless device to receive a Physical Downlink Control Channel (PDCCH) message sent by the base station, the PDCCH message including the resource information for receiving CSI-RS and TRS.

[0167] Example 30 includes the subject matter of Example 29, in which the resource information included in the PDCCH message indicates a predefined CSI-RS and TRS pattern.

[0168] According to Example 31, a method for paging in a wireless system is disclosed, the method including: transmitting, by a base station, resource information for receiving a channel state information reference signal (CSI-RS) and a tracking reference signal (TRS) to a user device in a reduced power state; transmitting, by the base station, resource information for receiving a channel state information reference signal (CSI-RS) and a tracking reference signal (TRS) to a user device that has exited the reduced power state based on the transmitted resource information; determining, by the base station, whether paging information to be transmitted in a first physical downlink shared channel (PDSCH) transmission for the user device exists; transmitting, by the base station, a downlink control information message, where the downlink control information message is based on a determination that paging information for the user device exists, and the user device is synchronized with the base station; and transmitting, by the base station, the first PDSCH transmission based on a determination that paging information for the user device exists.

[0169] Example 32 includes the subject matter of Example 31, and wherein transmitting, by the base station, resource information for receiving CSI-RS and TRS includes transmitting, by the base station, a system information block (SIB) to the user devices, the SIB including resource information for receiving CSI-RS and TRS for a set of two or more user devices.

[0170] Example 33 includes the subject matter of Example 32, wherein the SIB is transmitted periodically.

[0171] Example 34 includes the subject matter of Example 32, and further includes receiving, at the base station, a request from the user device for transmission of the SIB.

[0172] Example 35 includes the subject matter of Example 34, and wherein receiving a request to transmit an SIB includes receiving, by the base station, a random access channel (RACH) preamble including the request, and the CSI-RS and TRS transmitted and received are based on the request.

[0173] Example 36 includes the subject matter of Example 31 or 32, wherein the resource information for receiving CSI-RS and TRS is predefined.

[0174] Example 37 includes the subject matter of Example 36, wherein the resource information for receiving the CSI-RS and TRS is predefined based on one or more sets of configuration information.

[0175] Example 38 includes the subject matter of Example 31, and wherein transmitting, by the base station, the resource information for receiving the CSI-RS and the TRS, further includes transmitting, by the base station, a second PDSCH message to the user device before the first PDSCH message, the second PDSCH message including the resource information for receiving the CSI-RS and the TRS.

[0176] Example 39 includes the subject matter of Example 31, and wherein transmitting, by the base station, the resource information for receiving the CSI-RS and the TRS, further includes transmitting, by the base station, a Physical Downlink Control Channel (PDCCH) message to the user device, the PDCCH message including the resource information for receiving the CSI-RS and the TRS.

[0177] Example 40 includes the subject matter of Example 39, in which the resource information included in the PDCCH message indicates a predefined CSI-RS and TRS pattern.

[0178] According to Example 41, an apparatus including a processor is disclosed, wherein the processor is configured to: transmit resource information for receiving a Channel State Information Reference Signal (CSI-RS) and a Tracking Reference Signal (TRS) to a user device in a reduced power state; transmit the CSI-RS and the TRS to a user device that has exited the reduced power state based on the transmitted resource information; determine whether there is paging information to be transmitted in a first Physical Downlink Shared Channel (PDSCH) transmission for the user device; and transmit a downlink control information message, wherein based on a determination that the downlink control information message contains paging information for the user device, the user device is synchronized with the apparatus; and transmit the downlink control information message based on a determination that there is paging information for the user device.

[0179] Example 42 includes the subject matter of Example 41, and transmitting resource information for receiving CSI-RS and TRS includes transmitting, by the apparatus, a system information block (SIB) to the user device, the SIB including resource information for receiving CSI-RS and TRS for a set of two or more user devices.

[0180] Example 42 includes the subject matter of Example 42, wherein the SIB is transmitted periodically.

[0181] Example 44 includes the subject matter of example 42, wherein the processor is further configured to receive at the apparatus a request from the user device to transmit the SIB.

[0182] Example 45 includes the subject matter of Example 44, and wherein receiving a request to transmit an SIB includes receiving a random access channel (RACH) preamble including the request, and the CSI-RS and TRS transmitted and received are based on the request.

[0183] Example 46 includes the subject matter of Example 41 or 42, wherein the resource information for receiving CSI-RS and TRS is predefined.

[0184] Example 47 includes the subject matter of Example 46, wherein the resource information for receiving CSI-RS and TRS is predefined based on one or more sets of configuration information.

[0185] Example 48 includes the subject matter of Example 41, and wherein transmitting the resource information for receiving the CSI-RS and the TRS further includes transmitting, by the apparatus, a second PDSCH message to the user device before the first PDSCH message, the second PDSCH message including the resource information for receiving the CSI-RS and the TRS.

[0186] Example 49 includes the subject matter of Example 41, and wherein transmitting the resource information for receiving the CSI-RS and the TRS further includes: transmitting, by the apparatus, a Physical Downlink Control Channel (PDCCH) message to the user device, the PDCCH message including the resource information for receiving the CSI-RS and the TRS.

[0187] Example 50 includes the subject matter of Example 49, wherein the resource information included in the PDCCH message indicates a predefined CSI-RS and TRS pattern.

[0188] According to Example 51, an integrated circuit is disclosed having a circuit element, which is configured to: cause a base station to transmit resource information for receiving a channel state information reference signal (CSI-RS) and a tracking reference signal (TRS) to a user device in a reduced power state; cause the base station to transmit CSI-RS and TRS to a user device that has exited the reduced power state based on the transmitted resource information; determine whether there is paging information to be transmitted in a first physical downlink shared channel (PDSCH) transmission for the user device; cause the base station to transmit a downlink control information message, where the downlink control information message indicates that the user device is synchronized with the device, based on a determination that there is paging information for the user device; and cause the base station to transmit the first PDSCH transmission based on a determination that there is paging information for the user device.

[0189] Example 52 includes the subject matter of Example 51, and having the base station transmit resource information for receiving CSI-RS and TRS includes having the base station transmit, to the user device, a system information block (SIB), the SIB including resource information for receiving CSI-RS and TRS for a set of two or more user devices.

[0190] Example 53 includes the subject matter of Example 52, wherein the SIB is transmitted periodically.

[0191] Example 54 includes the subject matter of Example 52, wherein the circuit element is further configured to cause the base station to receive a request from the user device to transmit the SIB.

[0192] Example 55 includes the subject matter of Example 54, and receiving a request for an SIB includes receiving a random access channel (RACH) preamble including the request, and the CSI-RS and TRS transmitted and received are based on the request.

[0193] Example 56 includes the subject matter of Example 51 or 52, wherein the resource information for receiving CSI-RS and TRS is predefined.

[0194] Example 57 includes the subject matter of Example 56, wherein the resource information for receiving CSI-RS and TRS is predefined based on one or more sets of configuration information.

[0195] Example 58 includes the subject matter of Example 51, and wherein causing the base station to transmit resource information for receiving CSI-RS and TRS further includes causing the base station to transmit a second PDSCH message to the user device before the first PDSCH message, the second PDSCH message including resource information for receiving CSI-RS and TRS.

[0196] Example 59 includes the subject matter of Example 51, and causing the base station to transmit resource information for receiving CSI-RS and TRS further includes causing the base station to transmit a Physical Downlink Control Channel (PDCCH) message to the user device, the PDCCH message including the resource information for receiving CSI-RS and TRS.

[0197] Example 60 includes the subject matter of Example 59, and the resource information included in the PDCCH message indicates a predefined CSI-RS and TRS pattern.

[0198] Yet another embodiment may include a method that includes performing, by a device, any or all parts of the preceding embodiments.

[0199] Still further embodiments may include a non-transitory computer-accessible storage medium containing program instructions that, when executed on a device, cause the device to implement any or all portions of any of the aforementioned embodiments.

[0200] Still further embodiments may include a computer program, the computer program including instructions for carrying out any or all parts of any of the above described embodiments.

[0201] Another embodiment may include an integrated circuit comprising circuit elements configured to perform any or all of the above-described embodiments.

[0202] Yet another embodiment may include an apparatus comprising means for performing any or all of the elements of any of the preceding embodiments.

[0203] Yet another embodiment may include an apparatus comprising a processing element configured to cause a device to perform any or all of the elements of any of the preceding embodiments.

[0204] It is understood that use of personally identifiable information should comply with generally recognized privacy policies and practices that meet or exceed industry or government requirements for maintaining user privacy. In particular, personally identifiable information data should be managed and handled in a manner that minimizes the risk of unintended or unauthorized access or use, and the nature of authorized uses should be clearly indicated to users.

[0205] Aspects of the present disclosure may be implemented in any of a variety of forms. For example, some aspects may be implemented as a computer-implemented method, a computer-readable memory medium, or a computer system. Other aspects may be implemented using one or more custom-designed hardware devices, such as an ASIC. Still other aspects may be implemented using one or more programmable hardware elements, such as an FPGA.

[0206] In some aspects, a non-transitory computer-readable storage medium may be configured to store program instructions and / or data that, when executed by a computer system, cause the computer system to perform a method, such as any method described herein, or any combination of the methods described herein, or any subset of the methods described herein, or any combination of such subsets.

[0207] In some aspects, a device (e.g., a UE 106, a BS 102, a network element 600) may be configured to include a processor (or set of processors) and a memory medium, the memory medium storing program instructions, the processor configured to read and execute the program instructions from the memory medium, the program instructions executable to perform any of the various methods described herein (or any combination of the methods described herein, or any subset of any of the methods described herein, or any combination of such subsets). A device may be implemented in various forms.

[0208] Although 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, and it is intended that the following claims be interpreted to embrace all such variations and modifications.

Claims

1. 1. A method of paging in a wireless system, comprising: receiving, by a user device in a reduced power state, a system information block (SIB-x) transmitted by a base station, the SIB-x including resource information for receiving tracking reference signals (TRS) for a set of two or more user devices, the SIB-x including a dedicated SIB specially configured to indicate TRS resource information for the user device in the reduced power state; exiting, by the user device, from the reduced power state to receive the TRS based on the resource information; synchronizing, by the user device, with a base station to receive downlink control information messages based on the received TRS; receiving, by the user device, paging information in a first Physical Downlink Shared Channel (PDSCH) message based on the received downlink control information message; determining, by the user device, whether paging information is present in the first PDSCH message for the user device; and initiating, by the user device, a random access channel (RACH) procedure to create a radio resource control (RRC) connection based on a determination that paging information exists for the user device; The resource information for receiving the TRS is predefined based on a plurality of configuration information sets. method.

2. receiving, by the user device, the SIB-x via periodic transmission; The method of claim 1 further comprising:

3. The method of claim 1 , further comprising: transmitting, by the user device, a request for the SIB-x.

4. 4. The method of claim 3, wherein transmitting the request for the SIB-x includes transmitting a RACH preamble including the request, and wherein the received TRS is based on the request.

5. receiving the resource information for receiving the TRS, receiving a second PDSCH message transmitted by the base station prior to the first PDSCH message, the second PDSCH message including the resource information for receiving the TRS. The method of claim 1.

6. receiving the resource information for receiving the TRS, 2. The method of claim 1, further comprising receiving a Physical Downlink Control Channel (PDCCH) message transmitted by the base station, the PDCCH message including the resource information for receiving the TRS.

7. The method of claim 6 , wherein the resource information included in the PDCCH message indicates a predefined TRS pattern.

8. The antenna and a radio operably coupled to the antenna; a processor operably coupled to the radio; A wireless device comprising: receiving a system information block (SIB-x) transmitted by a base station in a reduced power state, the SIB-x including resource information for receiving tracking reference signals (TRS) for a set of two or more user devices, the SIB-x including a dedicated SIB specially configured to indicate TRS resource information for user devices in a reduced power state; based on the resource information, exiting the reduced power state to receive the TRS; synchronize with a base station based on the received TRS to receive a received control information message; receiving paging information in a first Physical Downlink Shared Channel (PDSCH) message based on the received downlink control information message; determining whether paging information is present in the first PDSCH message for the wireless device; and initiating a random access channel (RACH) procedure to establish a radio resource control (RRC) connection to the base station based on a determination that paging information is present for the wireless device. Wireless devices.

9. The wireless device of claim 8 , further configured to receive the SIB-x via periodic transmissions.

10. The wireless device of claim 8 , wherein the wireless device is further configured to transmit a request for the SIB-x.

11. 11. The wireless device of claim 10, wherein transmitting the request for the SIB-x includes transmitting a RACH preamble including the request, and wherein the received TRS is based on the request.

12. receiving the resource information for receiving the TRS, 10. The wireless device of claim 8, further comprising: receiving a second PDSCH message transmitted by the base station prior to the first PDSCH message, the second PDSCH message including the resource information for receiving the TRS.

13. receiving the resource information for receiving the TRS, 10. The wireless device of claim 8, further comprising: receiving a Physical Downlink Control Channel (PDCCH) message transmitted by the base station, the PDCCH message including the resource information for receiving the TRS.

14. The wireless device of claim 13 , wherein the resource information included in the PDCCH message indicates a predefined TRS pattern.

15. An integrated circuit comprising a circuit element, the circuit element comprising: causing a wireless device to receive, in a reduced power state, a system information block (SIB-x) transmitted by a base station, the SIB-x including resource information for receiving a channel state information reference signal (CSI-RS) and a tracking reference signal (TRS) for a set of two or more user devices, the SIB-x including a dedicated SIB specially configured to indicate TRS resource information for user devices in a reduced power state; causing the wireless device to exit the reduced power state to receive the TRS based on the resource information; causing the wireless device to synchronize with a base station based on the received TRS to receive downlink control information messages; causing the wireless device to receive paging information in a first Physical Downlink Shared Channel (PDSCH) message based on the received downlink control information message; determining whether paging information is present in the first PDSCH message for the wireless device; and causing the wireless device to initiate a random access channel (RACH) procedure to establish a radio resource control (RRC) connection to the base station based on a determination that paging information is present for the wireless device. Integrated circuit.

16. The circuit element is connected to the wireless device.

16. The integrated circuit of claim 15, further configured to cause the SIB-x to be received via periodic transmission.

17. The integrated circuit of claim 15, wherein the circuitry is further configured to cause the wireless device to transmit a request for the SIB-x.

18. 18. The integrated circuit of claim 17, wherein transmitting the request for the SIB-x includes transmitting a RACH preamble from the wireless device that includes the request, and wherein the received TRS is based on the request.

19. causing the wireless device to receive the resource information for receiving the TRS; 16. The integrated circuit of claim 15, further comprising: causing the wireless device to receive a second PDSCH message transmitted by the base station prior to the first PDSCH message, the second PDSCH message including the resource information for receiving the TRS.

20. causing the wireless device to receive the resource information for receiving the TRS; 16. The integrated circuit of claim 15, further comprising: causing the wireless device to receive a Physical Downlink Control Channel (PDCCH) message transmitted by the base station, the PDCCH message including resource information for receiving the TRS.

21. The integrated circuit of claim 20 , wherein the resource information included in the PDCCH message indicates a predefined TRS pattern.

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