WO2021152365A1 - Inter-radio access technology cell measurement - Google Patents

Abstract

Embodiments of apparatus and method for inter-radio access technology (RAT) cell measurement are disclosed. In an example, a request to measure a cell of a second RAT is received using a first RAT. Whether a first criterion and a second criterion are met is determined. The first criterion is based on a mode of the terminal device. In the mode, the terminal device supports the second RAT dependent on the first RAT. The second criterion is based on a condition for triggering an event associated with the second RAT. The condition is irrelevant to measuring the cell of the second RAT. In response to both the first and second criteria being met, a measurement of the cell of the second RAT is skipped.

Description

INTER-RADIO ACCESS TECHNOLOGY CELL MEASUREMENT

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 62/967,462 filed January 29, 2020, entitled “UE POWER SAVING IN LTE RRCJDLE SCENARIO WITH NR MEASUREMENT,” which is hereby incorporated by reference in its entirety.

BACKGROUND

[0002] Embodiments of the present disclosure relate to apparatus and method for wireless communication. [0003] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. A radio access technology (RAT) is the underlying physical connection method for a radio-based communication network. Many modem terminal devices, such as mobile device, support several RATs in one device, such as Global System for Mobile Communications (GSM), Universal Mobile Telecommunications Service (UMTS), Long-Term Evolution (LTE), or 5th- Generation (5G) New Radio (NR). A mobile device, while connected using a RAT, performs inter-RAT neighbor cell measurements and sends a measurement report to the network. Based on the measurement report provided by the mobile device, the network can initiate handover from one RAT to another RAT.

SUMMARY

[0004] Embodiments of apparatus and method for inter-RAT cell measurement are disclosed herein.

[0005] In one example, an apparatus includes at least one processor and memory storing instructions. The instructions, when executed by the at least one processor, cause the apparatus to receive, using a first RAT, a request to measure a cell of a second RAT. The instructions, when executed by the at least one processor, also cause the apparatus to determine whether a first criterion and a second criterion are met. The first criterion is based on a mode of the apparatus. In the mode, the apparatus supports the second RAT dependent on the first RAT. The second criterion is based on a condition for triggering an event associated with the second RAT. The condition is irrelevant to measuring the cell of the second RAT. The instructions, when executed by the at least one processor, further cause the apparatus to, in response to both the first and second criteria being met, skip a measurement of the cell of the second RAT.

[0006] In another example, a method implemented by a terminal device for wireless communication is disclosed. A request to measure a cell of a second RAT is received using a first RAT. Whether a first criterion and a second criterion are met is determined. The first criterion is based on a mode of the terminal device. In the mode, the terminal device supports the second RAT dependent on the first RAT. The second criterion is based on a condition for triggering an event associated with the second RAT. The condition is irrelevant to measuring the cell of the second RAT. In response to both the first and second criteria being met, a measurement of the cell of the second RAT is skipped.

[0007] In still another example, a non-transitory computer-readable medium is encoded with instructions that, when executed by at least one processor of a terminal device, perform a process. The process includes receiving, using a first RAT, a request to measure a cell of a second RAT. The process also includes determining whether a first criterion and a second criterion are met. The first criterion is based on a mode of the terminal device. In the mode, the terminal device supports the second RAT dependent on the first RAT. The second criterion is based on a condition for triggering an event associated with the second RAT. The condition is irrelevant to measuring the cell of the second RAT. The process further includes, in response to both the first and second criteria being met, skipping a measurement of the cell of the second RAT.

[0008] In yet another example, an apparatus includes a request receiving module, a criteria determination module, and a measurement module. The request receiving module is configured to receive, using a first RAT, a request to measure a cell of a second RAT. The criteria determination module is configured to determine whether a first criterion and a second criterion are met. The first criterion is based on a mode of the apparatus. In the mode, the apparatus supports the second RAT dependent on the first RAT. The second criterion is based on a condition for triggering an event associated with the second RAT. The condition is irrelevant to measuring the cell of the second RAT. The measurement module is configured to, in response to both the first and second criteria being met, skip a measurement of the cell of the second RAT.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable a person skilled in the pertinent art to make and use the present disclosure.

[0010] FIG. 1 illustrates an exemplary wireless network, according to some embodiments of the present disclosure.

[0011] FIG. 2 illustrates an exemplary multi-RAT wireless network, according to some embodiments of the present disclosure.

[0012] FIGs. 3A and 3B illustrate exemplary use cases of inter-RAT cell measurements, according to some embodiments of the present disclosure.

[0013] FIG. 4 illustrates a block diagram of an exemplary terminal device for inter-RAT cell measurement, according to some embodiments of the present disclosure.

[0014] FIG. 5 illustrates a detailed block diagram of an exemplary criteria determination module of the terminal device shown in FIG. 4, according to some embodiments of the present disclosure.

[0015] FIGs. 6A and 6B illustrate exemplary signal transmission patterns in inter-RAT cell measurements, according to some embodiments of the present disclosure.

[0016] FIG. 7 illustrates a flow chart of an exemplary method for inter-RAT cell measurement, according to some embodiments of the present disclosure.

[0017] FIGs. 8A and 8B illustrate exemplary timing diagrams for inter-RAT cell measurements, according to some embodiments of the present disclosure.

[0018] FIG. 9 illustrates a block diagram of an exemplary node, according to some embodiments of the present disclosure.

[0019] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

DETAILED DESCRIPTION

[0020] Although specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the pertinent art will recognize that other configurations and arrangements can be used without departing from the spirit and scope of the present disclosure. It will be apparent to a person skilled in the pertinent art that the present disclosure can also be employed in a variety of other applications.

[0021] It is noted that references in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” “some embodiments,” “certain embodiments,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it would be within the knowledge of a person skilled in the pertinent art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0022] In general, terminology may be understood at least in part from usage in context. For example, the term “one or more” as used herein, depending at least in part upon context, may be used to describe any feature, structure, or characteristic in a singular sense or may be used to describe combinations of features, structures or characteristics in a plural sense. Similarly, terms, such as “a,” “an,” or “the,” again, may be understood to convey a singular usage or to convey a plural usage, depending at least in part upon context. In addition, the term “based on” may be understood as not necessarily intended to convey an exclusive set of factors and may, instead, allow for existence of additional factors not necessarily expressly described, again, depending at least in part on context.

[0023] Various aspects of wireless communication systems will now be described with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, units, components, circuits, steps, operations, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, firmware, computer software, or any combination thereof. Whether such elements are implemented as hardware, firmware, or software depends upon the particular application and design constraints imposed on the overall system.

[0024] The techniques described herein may be used for various wireless communication networks, such as code division multiple access (CDMA) system, time division multiple access (TDMA) system, frequency division multiple access (FDMA) system, orthogonal frequency division multiple access (OFDMA) system, single -carrier frequency division multiple access (SC-FDMA) system, and other networks. The terms “network” and “system” are often used interchangeably. A CDMA network may implement a RAT such as Universal Terrestrial Radio Access (UTRA), evolved UTRA (E-UTRA), CDMA 2000, etc. A TDMA network may implement a RAT such as GSM. An OFDMA network may implement a RAT, such as LTE or NR. The techniques described herein may be used for the wireless networks and RATs mentioned above, as well as other wireless networks and RATs.

[0025] In some multi-RAT networks, in which a user equipment connects to more than one type of wireless communication network, inter-RAT cell measurement is performed by the user equipment in response to a request received from the network. For example, in an LTE-NR dual-RAT network, when the user equipment is in an idle state (e.g., LTE RRC_IDLE), an LTE base station may configure the user equipment to periodically perform NR neighbor cell measurements, which cause additional power consumption of the user equipment in the idle state.

[0026] Some user equipments can adapt the measurement rate based on certain criteria, e.g., the velocity of the user equipment. For example, when the velocity of the user equipment is low, NR neighbor cell measurement may be performed less frequently. Otherwise, the measurement is performed more frequently. By performing the NR cell measurement at a slower rate, power consumption can be reduced. However, such a solution can only reduce the power consumption in certain circumstances but cannot eliminate the power consumption from unnecessary measurements. Moreover, for some user equipments that benefit from the NR cell measurements, performing measurements at a slower rate may impact user experience. For example, the cell reselection time may be prolonged, or the user equipment may still show a 4G icon even inside a 5G coverage area.

[0027] Various embodiments in accordance with the present disclosure provide a set of criteria that helps the user equipments to decide whether there are benefits to perform inter-RAT cell measurements and to skip those unnecessary measurements despite the request from the network. For example, for some user equipments that are incapable of operating in an NR standalone operation mode or do not use NR measurement results to toggle 5G icon display, the NR cell measurement result may become useless for the LTE RRC_IDLE state operation. In some embodiments, a user equipment may skip the cell measurement of another RAT in response to whether two criteria are met, one based on the user equipment’s operation mode and the other based on the operator and/or manufacture’s condition for triggering an event associated with the other RAT. As a result, extra power consumption due to unnecessary inter-RAT cell measurements can be eliminated, thereby prolonging battery life, and improving end-user experience without any performance penalty.

[0028] FIG. 1 illustrates an exemplary wireless network 100, in which certain aspects of the present disclosure may be implemented, according to some embodiments of the present disclosure. As shown in FIG. 1, wireless network 100 may include a network of nodes, such as a user equipment (UE) 102, an access node 104, and a core network element 106. User equipment 102 may be any terminal device, such as a mobile phone, a desktop computer, a laptop computer, a tablet, a vehicle computer, a gaming console, a printer, a positioning device, a wearable electronic device, a smart sensor, or any other device capable of receiving, processing, and transmitting information, such as any member of a vehicle to everything (V2X) network, a cluster network, a smart grid node, or an Internet-of-Things (IoT) node. It is understood that user equipment 102 is illustrated as a mobile phone simply by way of illustration and not by way of limitation.

[0029] Access node 104 may be a device that communicates with user equipment 102, such as a wireless access point, a base station (BS), a Node B, an enhanced Node B (eNodeB or eNB), a next-generation NodeB (gNodeB or gNB), a cluster master node, or the like. Access node 104 may have a wired connection to user equipment 102, a wireless connection to user equipment 102, or any combination thereof. Access node 104 may be connected to user equipment 102 by multiple connections, and user equipment 102 may be connected to other access nodes in addition to access node 104. Access node 104 may also be connected to other user equipments. It is understood that access node 104 is illustrated by a radio tower by way of illustration and not by way of limitation.

[0030] Core network element 106 may serve access node 104 and user equipment 102 to provide core network services. Examples of core network element 106 may include a home subscriber server (HSS), a mobility management entity (MME), a serving gateway (SGW), or a packet data network gateway (PGW). These are examples of core network elements of an evolved packet core (EPC) system, which is a core network for the LTE system. Other core network elements may be used in LTE and in other communication systems. In some embodiments, core network element 106 includes an access and mobility management function (AMF) device, a session management function (SMF) device, or a user plane function (UPF) device, of a core network for the NR system. It is understood that core network element 106 is shown as a set of rack mounted servers by way of illustration and not by way of limitation.

[0031] Core network element 106 may connect with a large network, such as the Internet 108, or another Internet Protocol (IP) network, to communicate packet data over any distance. In this way, data from user equipment 102 may be communicated to other user equipments connected to other access points, including, for example, a computer 110 connected to Internet 108, for example, using a wired connection or a wireless connection, or to a tablet 112 wirelessly connected to Internet 108 via a router 114. Thus, computer 110 and tablet 112 provide additional examples of possible user equipments, and router 114 provides an example of another possible access node.

[0032] A generic example of a rack-mounted server is provided as an illustration of core network element 106. However, there may be multiple elements in the core network including database servers, such as a database 116, and security and authentication servers, such as an authentication server 118. Database 116 may, for example, manage data related to user subscription to network services. A home location register (HER) is an example of a standardized database of subscriber information for a cellular network. Fikewise, authentication server 118 may handle authentication of users, sessions, and so on. In the NR system, an authentication server function (AUSF) device may be the specific entity to perform user equipment authentication. In some embodiments, a single server rack may handle multiple such functions, such that the connections between core network element 106, authentication server 118, and database 116, may be local connections within a single rack.

[0033] As described below in detail, in some embodiments, in the idle state (e.g., FTE RRC_IDFE), user equipment 102 ignores the request from access node 104 for inter-RAT cell measurements (e.g., NR neighbor cell measurement) and skips the inter-RAT cell measurements, when a set of criteria are met, in order to avoid unnecessary power consumption.

[0034] Each of the elements of FIG. 1 may be considered a node of wireless network 100. More detail regarding the possible implementation of a node is provided by way of example in the description of a node 900 in FIG. 9. Node 900 may be configured as user equipment 102, access node 104, or core network element 106 in FIG. 1. Similarly, node 900 may also be configured as computer 110, router 114, tablet 112, database 116, or authentication server 118 in FIG. 1. As shown in FIG. 9, node 900 may include a processor 902, a memory 904, a transceiver 906. These components are shown as connected to one another by a bus, but other connection types are also permitted. When node 900 is user equipment 102, additional components may also be included, such as a user interface (UI), sensors, and the like. Similarly, node 900 may be implemented as a blade in a server system when node 900 is configured as core network element 106. Other implementations are also possible.

[0035] Transceiver 906 may include any suitable device for sending and/or receiving data. Node 900 may include one or more transceivers, although only one transceiver 906 is shown for simplicity of illustration. An antenna 908 is shown as a possible communication mechanism for node 900. Multiple antennas and/or arrays of antennas may be utilized. Additionally, examples of node 900 may communicate using wired techniques rather than (or in addition to) wireless techniques. For example, access node 104 may communicate wirelessly to user equipment 102 and may communicate by a wired connection (for example, by optical or coaxial cable) to core network element 106. Other communication hardware, such as a network interface card (NIC), may be included as well.

[0036] As shown in FIG. 9, node 900 may include processor 902. Although only one processor is shown, it is understood that multiple processors can be included. Processor 902 may include microprocessors, microcontrollers, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field- programmable gate arrays (FPGAs), programmable logic devices (PFDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout the present disclosure. Processor 902 may be a hardware device having one or many processing cores. Processor 902 may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Software can include computer instructions written in an interpreted language, a compiled language, or machine code. Other techniques for instructing hardware are also permitted under the broad category of software.

[0037] As shown in FIG. 9, node 900 may also include memory 904. Although only one memory is shown, it is understood that multiple memories can be included. Memory 904 can broadly include both memory and storage. For example, memory 904 may include random-access memory (RAM), read-only memory (ROM), static RAM (SRAM), dynamic RAM (DRAM), ferro-electric RAM (FRAM), electrically erasable programmable ROM (EEPROM), CD-ROM or other optical disk storage, hard disk drive (FIDD), such as magnetic disk storage or other magnetic storage devices, Flash drive, solid-state drive (SSD), or any other medium that can be used to carry or store desired program code in the form of instructions that can be accessed and executed by processor 902. Broadly, memory 904 may be embodied by any computer-readable medium, such as a non-transitory computer-readable medium.

[0038] In some embodiments, processor 902, memory 904, and transceiver 906 of node 900 are implemented (e.g., integrated) on a system-on-chip (SoC). For example, processor 902, memory 904, and transceiver 906 may be integrated on a baseband SoC (also known as a modem SoC, or a baseband model chipset), which can run an operating system (OS), such as a real-time operating system (RTOS) as its firmware. Various aspects of the present disclosure related to inter-RAT cell measurement may be implemented as software and/or firmware elements in a baseband SoC of user equipment 102. It is understood that in some examples, one or more of the software and/or firmware elements may be implemented as dedicated hardware elements in the SoC as well. Mapping to the LTE layer architecture, the implementation of the present disclosure may be at the protocol stack layer or the physical layer.

[0039] Referring back to FIG. 1, in some embodiments, wireless network 100 may be an inter-RAT wireless network, and user equipment 102 supports multiple RATs in the same device, such as GSM, UMTS, LTE, or NR. User equipment 102, while connected using a first RAT, may perform inter-RAT neighbor cell measurements and send measurement reports to access node 104. Based on the measurement report provided by user equipment 102, access node 104 may initiate handover from the first RAT to a second RAT, e.g., from LTE to NR or vice versa. Once the handover with the second RAT is completed, the channels used by the first RAT may be released. For example, an NR network may support two modes for inter-RAT with LTE — a standalone (SA) mode and a non-standalone (NSA) mode. The NR SA mode refers to using NR cells for both signaling and information transfer, i.e., in both control and user planes. The NR SA mode may include the 5G Core (5GC) architecture instead of relying on the LTE EPC to allow the deployment of NR without the LTE network. That is, a terminal device in the SA mode and an NR base station can establish connections and operate without the LTE infrastructure (e.g., EPC). In contrast, the NR NSA mode refers to an option of NR deployment that depends on the control plane of an existing LTE network for control functions, while NR is exclusively focused on the user plane.

[0040] FIG. 2 illustrates an exemplary multi-RAT wireless network 200, according to some embodiments of the present disclosure. Multi-RAT wireless network 200 may be an example of wireless network 100 that is in the NSA mode for inter-RAT between LTE and NR. As shown in FIG. 2, multi-RAT wireless network 200 may include a terminal device 202, an LTE base station 204 (e.g., eNB), an NR base station 206 (e.g., gNB), and an LTE EPC 208. Terminal device 202, such as a mobile phone, may be an example of user equipment 102 of wireless network 100 in FIG. 1; LTE base station 204 and NR base station 206 may be examples of access node 104 of wireless network 100 in FIG. 1; LTE EPC 208 may be an example of core network element 106 of wireless network 100 in FIG. 1. In some embodiments, multi-RAT wireless network 200 is in the multi-RAT dual connectivity (MR-DC) configuration in which a primary access node (e.g., LTE base station 204) functions as the controlling entity, utilizing a secondary access node (e.g., NR base station 206) for additional data capacity.

[0041] As shown in FIG. 2, terminal device 202 in the NSA mode may camp on or connect to an LTE cell 210, i.e., a first cell of a first RAT. To enable the E-UTRAN - NR dual connectivity (EN-DC) configuration, LTE EPC 208 can support connecting to NR base station 206. NR base station 206 may be connected to LTE EPC 208 at the user plane (e.g., including SGW and PGW), but not connected at the control plane (e.g., including MME). NR base station 206 may also be connected to LTE base station 204 to receive requests to activate and deactivate NR bearers. In the EN-DC configuration, terminal device 202 may be simultaneously connected to LTE base station 204 and NR base station 206. In some embodiments, LTE base station 204 periodically sends requests for measuring an NR cell 212, i.e., a second cell of a second RAT, to terminal device 202 for possible cell reselection.

[0042] While in the RRC_IDLE state, as required by the 3rd Generation Partnership Project (3GPP) technical specification (TS) 36.133 section 4.2.2.5.6 “Measurements of NR Cells,” a user equipment (e.g., terminal device 202) may need to perform inter-RAT measurement on NR frequency layers in order to detect candidate NR cells for possible cell reselection. Other than the reasons specified by 3GPP, the operator and/or manufacturer of the user equipment may also use the NR measurement result to decide whether to indicate 5G on the user equipment, for example, by displaying the 5G icon on the screen. FIGs. 3A and 3B illustrate exemplary use cases of inter-RAT cell measurements, according to some embodiments of the present disclosure. As shown in FIG. 3A, inter-RAT NR cell measurement may be beneficial for a terminal device 302 in the SA mode in order to reselect an NR cell. Terminal device 302, an example of user equipment 102 in FIG. 1, may be camped on an LTE cell of an LTE base station 304, an example of access node 104 in FIG. 1. By performing inter-RAT cell measurement in the RRC_IDLE state, e.g., NR neighbor cell measurement, terminal device 302 can reselect and be camped on an NR cell of an NR base station 306, another example of access node 104 in FIG. 1. Moreover, as shown in FIG. 3B, inter-RAT NR cell measurement may be beneficial for a terminal device 308 in the NSA mode as well for the purpose of indicating the NR-RAT on terminal device 308. For example, some operators or manufacturers of terminal device 308 may require showing 5G icon on the screen of terminal device 308 when terminal device 308 is camped on the FTE cell, and an NR cell is detected, as shown in FIG. 3B. In another example, some operators or manufacturers of a user equipment (e.g., terminal 302 in FIG. 3A) may require displaying 5G icon only when terminal device 302 in the SA mode camped on an NR cell. In still another example, some operators or manufacturers of a user equipment (e.g., terminal device 202 in FIG. 2) may require displaying a 5G icon when NR-RAT is added in the EN-DC configuration.

[0043] As described above, inter-RAT NR cell measurement may be beneficial for NR cell reselection or indicating NR-RAT (e.g., by displaying a 5G icon) on the user equipment when an NR cell is detected. That is, whether an inter-RAT cell measurement is necessary may be determined by evaluating a set of criteria. The set of criteria may include a first criterion that is based on the mode of the user equipment. In the mode, the user equipment supports the NR-RAT dependent on the non NR-RAT. For example, the first criterion is that the user equipment is in the NSA mode that supports NR dependent on FTE. The set of criteria may also include a second criterion that is based on the condition for triggering an event associated with the NR-RAT. The condition is irrelevant to NR cell measurement. For example, the second criterion is that the condition, as provided by the operator and/or the manufacturer of the user equipment, for indicating NR-RAT on the user equipment and the NR cell measurement are irrelevant. By evaluating the set of criteria based on the relevant information of the user equipment, the inter-RAT cell measurement can be skipped or performed to avoid unnecessary power consumption without jeopardizing user experience and device performance.

[0044] As an example of a user equipment that implements the inter-RAT cell measurement scheme described above, FIG. 4 illustrates a block diagram of an exemplary terminal device 400 for inter-RAT cell measurement, according to some embodiments of the present disclosure. Terminal device 400 may include a processor 402, a memory 404, and a transceiver 406, which may be examples of processor 902, memory 904, and transceiver 906 described above in detail with respect to FIG. 9. In some embodiments, some or all of processor 402, memory 404, and transceiver 406 are integrated on a baseband SoC (also known as a modem SoC or a baseband model chipset).

[0045] As shown in FIG. 4, terminal device 400 may include multiple modules implemented as software and/or firmware modules executed by processor 402, including, for example, a state transition module 412, a request receiving module 414, a criteria determination module 416, and a measurement module 418. As described above, processor 402 may run an operating system, such as an RTOS, that executes instructions stored in memory 404 (e.g., an on-chip RAM) to implement the above-mentioned software and/or firmware modules. It is understood that in some examples, one or more of the above-mentioned software and/or firmware modules may be implemented as dedicated hardware elements in the SoC as well. Mapping to the FTE layer architecture, the implementation of the above-mentioned modules may be at the protocol stack layer or the physical layer. Terminal device 400 may also include various databases stored in memory 404 (e.g., an off-chip RAM or external storage) that store the information about the operation mode of terminal device 400 (UE mode 420) and the information about the event triggering condition from the operator and/or manufacturer of terminal device 400 (operator/manufacturer condition 422).

[0046] Transceiver 406 may be configured to receive signals from the network, such as access node 104 in FIG. 1. In some embodiments, the network is an inter-RAT wireless network having a first RAT (e.g., FTE) and a second RAT (e.g., NR). It is understood that the first and second RATs are not limited to FTE and NR, respectively, and may include any other suitable RATs, such as GSM or UMTS for cellular networks, and Bluetooth or Wi-Fi for wireless local area networks (WFANs), with any suitable combinations thereof. Terminal device 400 may be camped on an FTE cell of an FTE base station (e.g., eNB), and transceiver 406 may communicate with the FTE base station, for example, by receiving radio resource control (RRC) messages and paging messages based on the RRC protocol when terminal device 400 is in an idle state (e.g., RRC_IDLE). In some embodiments, for example when terminal device 400 is in the SA mode, or when terminal device 400 is in the NSA mode and the inter-RAT wireless network is in the EN-DC configuration, transceiver 406 may also communicate with an NR base station (e.g., gNB), for example, by communicating synchronization signal block (SSB) signals for NR cell detection, measurement, and measurement result reporting.

[0047] State transition module 412 may be configured to cause terminal device 400 to enter an idle state. In some embodiments in which terminal device 400 is camped on the LTE cell using LTE RAT, state transition module 412 implements the RRC protocol in the RRC layer (part of protocol stack layer) between terminal device 400 and the LTE base station to change states between the various RRC states, such as an idle state (e.g., RRC_IDLE) and various connected states (e.g., RRC_CONNECTED, CELL_PCH, CELL_DCH, CELL_FACH, and URA_PCH). For example, 3GPP TS 36.331 provides various ways of transition into RRC_IDLE, for example, through cell reselection or connection release. In some embodiments, by monitoring the LTE paging messages received by transceiver 406 in each paging cycle, state transition module 412 causes terminal device 400 to enter the RRC_IDLE in response to cell reselection or connection release.

[0048] Request receiving module 414 may be configured to receive, using the first RAT, a request to measure a cell of the second RAT. In some embodiments, during the idle state (e.g., RRC_IDLE), the access node of the first RAT (e.g., the LTE base station) on which terminal device 400 is camped may send a request to measure a second RAT cell (e.g., NR cell) for possible cell reselection or other purposes. Request receiving module 414 may receive the second RAT cell measurement requests (e.g., NR cell measurement), for example, in the paging messages as part of the RRC protocol, when terminal device 400 is in the idle state.

[0049] Criteria determination module 416 may be configured to determine whether a set of criteria is met in order to decide whether to perform or skip the second RAT cell measurement. The set of criteria may include at least two criteria related to the second RAT (e.g., NR). In some embodiments, the first criterion is based on the mode of terminal device 400 in which terminal device 400 supports the second RAT dependent on the first RAT, and the second criterion is based on a condition for triggering an event associated with the second RAT, where the condition is irrelevant to measuring the cell of the second RAT. It is understood that although two criteria are described below in detail for evaluating whether to perform or skip the second RAT cell measurement, any other suitable criteria related to the second RAT may be included in the set of criteria as well.

[0050] The mode of terminal device 400 in which terminal device 400 supports the second RAT dependent on the first RAT may include the inter-RAT mode of terminal device 400 between first and second RATs (e.g., LTE and NR), for example, the NSA mode. That is, the first criterion may evaluate whether terminal device 400 can establish a connection with a second RAT access node (e.g., NR base station) independent of the first RAT core network element (e.g., LTE EPC) upon detection of the second RAT cell (e.g., NR cell) through cell reselection. Because there may be a mixture of terminal devices 400 in the SA mode and terminal devices 400 in the NSA mode, an LTE base station may need to simultaneously serve both modes of terminal devices 400. In order to allow terminal devices 400 in the SA mode to identify and reselect NR cells, the LTE base station may need to configure NR neighbor cells in the broadcast messages (e.g., paging messages) addressing to terminal devices 400, including terminal devices 400 in the NSA mode that cannot reselect NR cells independent of LTE. In one example, the first criterion may include that terminal device 400 is in the NSA mode, i.e., those do not support reselecting NR cells independent of LTE.

[0051] The event associated with the second RAT may include indicating the second RAT on terminal device 400. The condition for triggering the indication of the second RAT on terminal device 400 may be irrelevant to measuring the second RAT cell. That is, there is no need to measure the second RAT cell in order to indicate the second RAT cell on terminal device 400, according to some embodiments. In some embodiments, indicating the second RAT on terminal device 400 includes displaying an icon, logo, text, or any other suitable symbols representing the second RAT (e.g., the word “5G”, “NR,” or “5G NR,” or a 5G icon) on the screen of terminal device 400. For example, a 5G icon may be displayed on the upper right comer of the information bar of a mobile device. The operator of terminal device 400, such as a mobile carrier, or the manufacturer of terminal device 400, may set up one or more conditions for displaying the 5G icon on terminal device 400. In some embodiments, the conditions are in a pre-agreement between the operator and the manufacturer of terminal device 400. In one example, some operators or manufacturers of terminal device 400 may require showing 5G icon on the screen of terminal device 400 when terminal device 400 is camped on the LTE cell, and an NR cell is detected, for example, as shown in FIG. 3B. In another example, some operators or manufacturers of terminal device 400 may require displaying 5G icon only when terminal device 400 in the SA mode is camped on an NR cell, as shown in FIG. 3A. In still another example, some operators or manufacturers of terminal device 400 may require displaying 5G icon when NR-RAT is added in the EN-DC configuration, as shown in FIG. 2. That is, the second criterion may evaluate whether the measurement of the second RAT cell (e.g., NR cell measurement) is a prerequisite mandated by the operator or manufacturer of terminal device 400 in order to achieve certain functions, e.g., indicating the second RAT on terminal device 400. The second criterion may include that the measurement of the cell of the second RAT is irrelevant to the condition for indicating the second RAT on terminal device 400. For example, the performance of NR cell measurement may not affect displaying 5G icon on the screen of terminal device 400. In other words, neither the operator nor the manufacturer requires inter-RAT NR cell measurement in the RRC_IDLE state in order to display a 5G icon. It is understood that the event associated with the second RAT is not limited to indicating the second RAT on terminal device 400 and may include any suitable events associated with the second RAT. The condition thus may be any suitable conditions that can trigger the events associated with the second RAT, while the conditions are irrelevant to measuring the second RAT.

[0052] FIG. 5 illustrates a detailed block diagram of exemplary criteria determination module 416 of terminal device 400 shown in FIG. 4, according to some embodiments of the present disclosure. To perform the criteria determination function, criteria determination module 416 may include an information retrieval unit 502, a mode determination unit 504, a condition determination unit 506, AND logic 508, an output unit 510, and a condition update monitoring unit 512. Each element in criteria determination module 416 may be implemented as a software and/or firmware unit.

[0053] Information retrieval unit 502 may be operatively coupled to memory 404 and configured to obtain information about UE mode 420 and condition 422 stored in memory 404. In some embodiments, information about UE mode 420 includes the inter-RAT mode of terminal device 400, for example, either the SA mode or the NSA mode. The inter-RAT mode may be a constant through the entire life of terminal device 400 and thus, may be stored in a ROM once it is manufactured by the manufacturer or initialized by the operator, which may not be changed later. In some embodiments, condition 422 includes the conditions for indicating the second RAT on terminal device 400, which may be set up by the manufacturer, the operator, or both of the manufacturer and the operator, for example, in a pre-agreement therebetween. In one example, the conditions may be a constant through the entire life of terminal device 400 and thus, may be stored in a ROM once it is manufactured by the manufacturer or initialized by the operator, which may not be changed later. In another example, one or more conditions may be updated during the life cycle of terminal device 400 and thus, stored in non-volatile read-write memory, such as Flash memory, which may be updated later.

[0054] Mode determination unit 504 may be operatively coupled to information retrieval unit 502 and configured to determine whether the first criterion based on the mode of terminal device 400 in which terminal device 400 supports the second RAT dependent on the first RAT is met. In some embodiments, the first criterion is that terminal device 400 is in the NSA mode, and mode determination unit 504 checks the retrieved information about UE mode 420, e.g., the inter-RAT mode of terminal device 400, to determine whether terminal device 400 is in the NSA mode. The first criterion may be met if the mode of terminal device 400 supporting the second RAT is the NSA mode.

[0055] Similarly, condition determination unit 506 may be operatively coupled to information retrieval unit 502 and configured to determine whether the second criterion based on the condition for trigging an event associated with the second RAT, where the condition is irrelevant to measuring the second RAT cell, is met. The condition may be provided by the operator and/or the manufacturer of terminal device 400. In some embodiments, the second criterion is that the measurement of the cell of the second RAT is irrelevant to the condition for indicating the second RAT on terminal device 400, and condition determination unit 506 checks the retrieved information about condition 422 including the condition for indicating the second RAT on terminal device 400, e.g., displaying a 5G icon, to determine whether the measurement of the cell of the second RAT is irrelevant to the condition. The second criterion may be met if the measurement of the cell of the second RAT is irrelevant to the condition in condition 422, e.g., NR cell measurement is not needed for displaying a 5G icon.

[0056] The determination results from mode determination unit 504 and condition determination unit 506, i.e., whether each of the first and second criteria is met, may be outputted to AND logic 508, which returns a True value (positive, “1”) only when both first and second criteria are met. Otherwise, AND logic 508 may return a False value (negative, “0”). It is understood that additional determination units for checking additional criteria may be included in criteria determination module 416 as well in some examples.

[0057] Output unit 510 may be configured to forward the result of AND logic 508 to measurement module 418. In some embodiments, output unit 510 may also send the result to a result database 514 to update the previously stored result obtained from the last criteria determination session. In some embodiments, criteria determination module 416 performs the criteria determination session every time in response to receiving the request to measure the second RAT cell. That is, the request may automatically trigger criteria determination module 416 to perform the criteria determination session and output a new determination result. As described above, UE mode 420 supporting the second RAT, such as the inter-RAT mode of terminal device 400, may be a constant, meaning that the result from mode determination unit 504 may be a constant as well; the result from condition determination unit 506 may be changed only when condition 422 is updated by the operator and/or the manufacture of terminal device 400. In some embodiments, condition update monitoring unit 512 is configured to determine whether condition 422 associated with the second RAT is updated and notify condition determination unit 506 after determining that an update is made to condition 422. As a result, condition determination unit 506 may determine whether the second criterion is met in response to condition 422 being updated. Otherwise, the result of condition determination unit 506 and the resulting output of AND logic 508 may remain the same as the previous result stored in result database 514. In some embodiments, if condition update monitoring unit 512 does not detect an update to condition 422, output unit 510 retrieves the last result from result database 514, instead receives a new result from AND logic 508, and forwards the last result to measurement module 418.

[0058] Referring back to FIG. 4, measurement module 418 may be configured to perform or skip the measurement of the second RAT cell based on the determination result from criteria determination module 416. In some embodiments, in response to both the first and second criteria being met (e.g., the result of AND logic 508 is True), measurement module 418 is configured to skip the measurement of the second RAT cell. For example, if terminal device 400 cannot reselect NR cells independent of the first RAT (e.g., in the NSA mode) and does not need to display 5G icon based on NR measurement results (i.e., the NR measurement result and 5G icon display are irrelevant), there may not be any impact on end-user experience. As a result, the NR measurement may be skipped to reduce power consumption. In some embodiments, in response to at least one of the first and second criteria not being met (e.g., the result of AND logic 508 is False), measurement module 418 is configured to measure the second RAT cell. For example, when any one of the first and second criteria is not met, or both the first and second criteria are not met, measurement module 418 may cause terminal device 400 to perform the NR cell measurement and send the measurement result in a measurement report to the access node of the first RAT (e.g., the FTE base station) through transceiver 406.

[0059] FIGs. 6A and 6B illustrate exemplary signal transmission patterns in inter-RAT cell measurements, according to some embodiments of the present disclosure. As shown in FIGs. 6 A and 6B, in the RRC_IDFE state, terminal device 400 may wake up in a discontinuous reception (DRX) manner in each FTE paging occasion 602 according to the paging cycles, varying as 32, 64, 128, and up to 256 radio frames. When at least one of the first and second criteria is not met, for example, when terminal device 400 is in the SA node and/or when inter-RAT cell measurement is needed to indicate the second RAT on terminal device 400, NR measurements may be performed in response to each inter-RA cell measurement request. For example, as shown in FIG. 6A, NR cell measurement requests may be sent in each FTE paging occasion 602 in the RRC_IDFE state, and terminal device 400 may wake up in each SSB 604 for NR cell measurements. As SSBs 604 may not be time -overlapped with FTE paging occasions 602, the extra wake-ups in the RRC_IDFE state for receiving SSBs 604 may consume additional battery power of terminal device 400. In contrast, as shown in FIG. 6B, when both the first and second criteria are met, for example, when terminal device 400 is in the NSA node and when inter-RAT cell measurement is not needed to indicate the second RAT on terminal device 400, NR cell measurements may be skipped, such that no SSBs 604 are needed for NR measurements, thereby saving battery power of terminal device 400.

[0060] FIG. 7 illustrates a flow chart of an exemplary method 700 for inter-RAT cell measurement, according to some embodiments of the present disclosure. FIGs. 8A and 8B illustrate exemplary timing diagrams for inter-RAT cell measurements, according to some embodiments of the present disclosure. FIGs. 7, 8A, and 8B will be described together. Examples of the apparatus that can perform operations of method 700 include, for example, terminal device 400 (or the baseband SoC therein) depicted in FIG. 4 or any other apparatus disclosed herein. It is understood that the operations shown in method 700 are not exhaustive and that other operations can be performed as well before, after, or between any of the illustrated operations. Further, some of the operations may be performed simultaneously, or in a different order than shown in FIG. 7.

[0061] Referring to FIG. 7, method 700 starts at operation 702, in which an idle state is entered. In some embodiments, the idle state is the idle state of a first RAT, such as FTE RRC_IDFE. State transition module 412 implemented on processor 402 may cause terminal device 400 to enter the idle state. As shown in FIGs. 8A and 8B, an FTE base station 802 and a user equipment 804 (e.g., terminal device 400) may implement the RRC protocol in the RRC layer, and user equipment 804 may enter the RRC_IDFE state at timing 806 to reduce power consumption. The entire process of method 700 including operations 702, 704, 706, 708, 710, and 712 described below may be performed in the idle state of terminal device. [0062] Method 700 proceeds to operation 704, as illustrated in FIG. 7, in which a request to measure a cell of a second RAT is received using a first RAT. The request may be sent from the network, for example, an access node of the first RAT. In some embodiments, the first RAT includes LTE, and the second RAT includes NR. Request receiving module 414 implemented on processor 402 may receive, using the first RAT, the request to measure the second RAT cell. As shown in FIGs. 8 A and 8B, in the RRC_IDLE state, LTE base station 802 may send an NR cell measurement request at timing 808 to user equipment 804 in an LTE paging occasion.

[0063] Method 700 proceeds to operation 706, as illustrated in FIG. 7, in which information stored in the terminal device about the mode of the terminal device in which the terminal device supports the second RAT dependent on the first RAT, and information stored in the terminal device about the condition for triggering an event associated with the second RAT, where the condition is irrelevant to measuring the cell of the second RAT are obtained. In some embodiments, the mode of the terminal device includes an inter-RAT mode of the terminal device between the first RAT and the second RAT, such as the NSA mode. In some embodiments, the condition includes the condition for indicating the second RAT on the terminal device, for example, displaying a 5G icon on the screen. Criteria determination module 416 implemented on processor 402 may obtain the information stored in memory 404 about the mode of terminal device 400 and the condition from the operator and/or manufacturer of terminal device 400.

[0064] Method 700 proceeds to operation 708, as illustrated in FIG. 7, in which whether a first criterion based on the mode of the terminal device, and a second criterion based on the condition, are met are determined. In some embodiments, the first criterion includes that the terminal device is in the NSA mode. In some embodiments, the second criterion includes that the measurement of the cell of the second RAT is irrelevant to the condition for indicating the second RAT on the terminal device. Criteria determination module 416 implemented on processor 402 may determine whether the first and second criteria are met.

[0065] Method 700 proceeds to operation 710, as illustrated in FIG. 7, in which in response to both the first and second criteria being met, the measurement of the cell of the second RAT is skipped. Alternatively, at operation 712, in response to at least one of the first and second criteria not being met, the cell of the second RAT is measured. The measurement result may be sent in a measurement report to the network where the measurement request is sent from, for example, the access node of the first RAT. Measurement module 418 implemented on processor 402 may skip or perform the measurement of the cell of the second RAT, depending on the determination results of the first and second criteria.

[0066] In one example shown in FIG. 8A, user equipment 804 may first check whether user equipment 804 is in the NSA mode, i.e., a non-standalone user equipment, at timing 810. If the result is negative (answering “No,” one criterion for skipping the NR cell measurement is not met), then user equipment 804 may perform the NR cell measurement at timing 812 and return the NR measurement result in a measurement report to LTE base station 802 at timing 814. If the result is positive (answering “Yes,” one criterion for skipping the NR measurement is met), then user equipment 804 may further check whether NR cell measurement (meas.) is not needed to show a 5G icon on user equipment 804 at timing 816. If the result is negative (another criterion for skipping the NR cell measurement is not met), then user equipment 804 may perform the NR cell measurement at timing 812 and return the NR cell measurement result in the measurement report to LTE base station 802 at timing 814. Otherwise, user equipment 804 may ignore the NR cell measurement request and skip the NR cell measurement at timing 818. No NR cell measurement result may be returned to LTE base station 802 in this situation.

[0067] In another example shown in FIG. 8B, user equipment 804 may first check whether NR cell measurement is not needed to show a 5G icon on user equipment 804 at timing 816. If the result is negative, then user equipment 804 may perform the NR cell measurement at timing 812 and return the NR measurement result in a measurement report to LTE base station 802 at timing 814. If the result is positive, then user equipment 804 may further check whether user equipment 804 is in the NSA mode at timing 810. If the result is negative, then user equipment 804 may perform the NR cell measurement at timing 812 and return the NR cell measurement result in the measurement report to LTE base station 802 at timing 814. Otherwise, user equipment 804 may ignore the NR cell measurement request and skip the NR cell measurement at timing 818. No NR cell measurement result may be returned to LTE base station 802 in this situation.

[0068] FIGs. 8 A and 8B illustrate different examples in which the first criterion and the second criterion are checked sequentially, i.e., one after another. Since both criteria need to be met in order to skip the NR cell measurement, one criterion that is checked later may be skipped if another criterion check first is not met. It is understood that although not shown in FIGs. 8A and 8B, in some examples, the first criterion and the second criterion may be checked simultaneously at the same timing. [0069] In various aspects of the present disclosure, the functions described herein may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or encoded as instructions or code on a non-transitory computer-readable medium. Computer- readable media includes computer storage media. Storage media may be any available media that can be accessed by a computing device, such as node 900 in FIG. 9. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, HDD, such as magnetic disk storage or other magnetic storage devices, Flash drive, SSD, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a processing system, such as a mobile device or a computer. Disk and disc, as used herein, includes CD, laser disc, optical disc, DVD, and floppy disk where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0070] According to one aspect of the present disclosure, an apparatus can include at least one processor and memory including storing instructions. The instructions, when executed by the at least one processor, cause the apparatus to receive, using a first RAT, a request to measure a cell of a second RAT. The instructions, when executed by the at least one processor, also cause the apparatus to determine whether a first criterion and a second criterion are met. The first criterion is based on a mode of the apparatus. In the mode, the apparatus supports the second RAT dependent on the first RAT. The second criterion is based on a condition for triggering an event associated with the second RAT. The condition is irrelevant to measuring the cell of the second RAT. The instructions, when executed by the at least one processor, further cause the apparatus to in response to both the first and second criteria being met, skip a measurement of the cell of the second RAT. [0071] In some embodiments, the first RAT includes LTE, and the second RAT includes NR.

[0072] In some embodiments, the first criterion includes that the apparatus is in an NSA mode.

[0073] In some embodiments, the event associated with the second RAT includes indicating the second RAT on the apparatus.

[0074] In some embodiments, the condition is provided by at least one of an operator or a manufacturer of the apparatus.

[0075] In some embodiments, execution of the instructions further causes the apparatus to enter an idle state prior to receiving the request to measure the cell of the second RAT.

[0076] In some embodiments, execution of the instructions further causes the apparatus to obtain information stored in the apparatus about the mode of the apparatus and the condition.

[0077] In some embodiments, execution of the instructions further causes the apparatus to in response to at least one of the first and second criteria not being met, measure the cell of the second RAT.

[0078] In some embodiments, execution of the instructions further causes the apparatus to determine whether the condition is updated, and determine whether the second criterion is met after determining that the condition is updated.

[0079] According to another aspect of the present disclosure, a method implemented by a terminal device for wireless communication is disclosed. A request to measure a cell of a second RAT is received using a first RAT. Whether a first criterion and a second criterion are met is determined. The first criterion is based on a mode of the terminal device. In the mode, the terminal device supports the second RAT dependent on the first RAT. The second criterion is based on a condition for triggering an event associated with the second RAT. The condition is irrelevant to measuring the cell of the second RAT. In response to both the first and second criteria being met, measurement of the cell of the second RAT is skipped.

[0080] In some embodiments, the first RAT includes LTE, and the second RAT includes NR.

[0081] In some embodiments, the first criterion includes that the terminal device is in an NSA mode.

[0082] In some embodiments, the event associated with the second RAT includes indicating the second RAT on the terminal device.

[0083] In some embodiments, the condition is provided by at least one of an operator or a manufacturer of the terminal device.

[0084] In some embodiments, an idle state is entered prior to receiving the request to measure the cell of the second RAT.

[0085] In some embodiments, information stored in the terminal device about the mode of the apparatus and the condition is obtained.

[0086] In some embodiments, in response to at least one of the first and second criteria not being met, the cell of the second RAT is measured.

[0087] In some embodiments, whether the condition is updated is determined, and whether the second criterion is met is determined after determining that the condition is updated. [0088] According to still another aspect of the present disclosure, a non-transitory computer-readable medium is encoded with instructions that, when executed by at least one processor of a terminal device, perform a process. The process includes receiving, using a RAT, a request to measure a cell of a second RAT. The process also includes determining whether a first criterion and a second criterion are met. The first criterion is based on a mode of the terminal device. In the mode, the terminal device supports the second RAT dependent on the first RAT. The second criterion is based on a condition for triggering an event associated with the second RAT. The condition is irrelevant to measuring the cell of the second RAT. The process further includes, in response to both the first and second criteria being met, skipping measurement of the cell of the second RAT.

[0089] In some embodiments, the first RAT includes LTE, and the second RAT includes NR.

[0090] In some embodiments, the first criterion includes that the terminal device is in an NSA mode.

[0091] In some embodiments, the event associated with the second RAT includes indicating the second RAT on the terminal device.

[0092] In some embodiments, the condition is provided by at least one of an operator or a manufacturer of the terminal device.

[0093] In some embodiments, the process further includes entering an idle state prior to receiving the request to measure the cell of the second RAT.

[0094] In some embodiments, the process further includes obtaining information stored in the apparatus about the mode of the apparatus and the condition.

[0095] In some embodiments, the process further includes in response to at least one of the first and second criteria not being met, measuring the cell of the second RAT.

[0096] In some embodiments, the process further includes determining whether the condition is updated, and determining whether the second criterion is met only in response to the condition being updated.

[0097] According to yet another aspect of the disclosure, an apparatus includes a request receiving module, a criteria determination module, and a measurement module. The request receiving module is configured to receive, using a first RAT, a request to measure a cell of a second RAT. The criteria determination module is configured to determine whether a first criterion and a second criterion are met. The first criterion is based on a mode of the apparatus. In the mode, the apparatus supports the second RAT dependent on the first RAT. The second criterion is based on a condition for triggering an event associated with the second RAT. The condition is irrelevant to measuring the cell of the second RAT. The measurement module is configured to in response to both the first and second criteria being met, skip a measurement of the cell of the second RAT.

[0098] In some embodiments, the first RAT includes LTE, and the second RAT includes NR.

[0099] In some embodiments, the first criterion includes that the apparatus is in an NSA mode.

[0100] In some embodiments, the event associated with the second RAT includes indicating the second RAT on the apparatus.

[0101] In some embodiments, the condition is provided by at least one of an operator or a manufacturer of the apparatus.

[0102] In some embodiments, the apparatus further includes a state transition module configured to enter an idle state prior to receiving the request to measure the cell of the second RAT.

[0103] In some embodiments, the criteria determination module is further configured to obtain information stored in the apparatus about the mode of the apparatus and the condition.

[0104] In some embodiments, the measurement module is further configured to, in response to at least one of the first and second criteria not being met, measure the cell of the second RAT.

[0105] In some embodiments, the criteria determination module is further configured to determine whether the condition is updated, and determine whether the second criterion is met after determining that the condition is updated.

[0106] The foregoing description of the specific embodiments will so reveal the general nature of the present disclosure that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance.

[0107] Embodiments of the present disclosure have been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.

[0108] The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present disclosure as contemplated by the inventor(s), and thus, are not intended to limit the present disclosure and the appended claims in any way.

[0109] Various functional blocks, modules, and steps are disclosed above. The particular arrangements provided are illustrative and without limitation. Accordingly, the functional blocks, modules, and steps may be re-ordered or combined in different ways than in the examples provided above. Likewise, certain embodiments include only a subset of the functional blocks, modules, and steps, and any such subset is permitted.

[0110] The breadth and scope of the present disclosure should not be limited by any of the above -described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

WHAT IS CLAIMED IS:

1. An apparatus for wireless communication, comprising: at least one processor; and memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, using a first radio access technology (RAT), a request to measure a cell of a second

RAT; determine whether a first criterion and a second criterion are met, wherein the first criterion is based on a mode of the apparatus, in the mode, the apparatus supporting the second RAT dependent on the first RAT, and wherein the second criterion is based on a condition for triggering an event associated with the second RAT, the condition being irrelevant to measuring the cell of the second RAT ; and in response to both the first and second criteria being met, skip a measurement of the cell of the second RAT.

2. The apparatus of claim 1, wherein the first RAT comprises Long-Term Evolution (LTE), and the second RAT comprises New Radio (NR).

3. The apparatus of claim 1 or 2, wherein the first criterion comprises that the apparatus is in a non-standalone (NSA) mode.

4. The apparatus of any one of claims 1-3, wherein the event associated with the second RAT comprises indicating the second RAT on the apparatus.

5. The apparatus of any one of claims 1-4, wherein the condition is provided by at least one of an operator or a manufacturer of the apparatus.

6. The apparatus of any one of claims 1-5, wherein execution of the instructions further causes the apparatus to enter an idle state prior to receiving the request to measure the cell of the second RAT.

7. The apparatus of any one of claims 1-6, wherein execution of the instructions further causes the apparatus to obtain information stored in the apparatus about the mode of the apparatus and the condition.

8. The apparatus of any one of claims 1-7, wherein execution of the instructions further causes the apparatus to, in response to at least one of the first and second criteria not being met, measure the cell of the second RAT.

9. The apparatus of any one of claims 1-8, wherein execution of the instructions further causes the apparatus to: determine whether the condition is updated; and determine whether the second criterion is met after determining that the condition is updated.

10. A method implemented by a terminal device for wireless communication, comprising: receiving, using a first radio access technology (RAT), a request to measure a cell of a second RAT ; determining whether a first criterion and a second criterion are met, wherein the first criterion is based on a mode of the terminal device, in the mode, the terminal device supporting the second RAT dependent on the first RAT, and wherein the second criterion is based on a condition for triggering an event associated with the second RAT, the condition being irrelevant to measuring the cell of the second RAT ; and in response to both the first and second criteria being met, skipping a measurement of the cell of the second RAT.

11. The method of claim 10, wherein the first RAT comprises Long-Term Evolution (LTE), and the second RAT comprises New Radio (NR).

12. The method of claim 10 or 11, wherein the first criterion comprises that the terminal device is in a non-standalone (NSA) mode.

13. The method of any one of claims 10-12 wherein the event associated with the second RAT comprises indicating the second RAT on the terminal device.

14. The method of any one of claims 10-13, wherein the condition is provided by at least one of an operator or a manufacturer of the apparatus.

15. The method of any one of claims 10-14, further comprising entering an idle state prior to receiving the request to measure the cell of the second RAT.

16. The method of any one of claims 10-15, further comprising obtaining information stored in the terminal device about the mode of the terminal device and the condition.

17. The method of any one of claims 10-16, further comprising, in response to at least one of the first and second criteria not being met, measuring the cell of the second RAT.

18. The method of any one of claims 10-17, further comprising: determining whether the condition is updated; and determining whether the second criterion is met after determining that the condition is updated.

19. A non-transitory computer-readable medium encoded with instructions that, when executed by at least one processor of a terminal device, perform a process comprising: receiving, using a first radio access technology (RAT), a request to measure a cell of a second RAT ; determining whether a first criterion and a second criterion are met, wherein the first criterion is based on a mode of the terminal device, in the mode, the terminal device supporting the second RAT dependent on the first RAT, and wherein the second criterion is based on a condition for triggering an event associated with the second RAT, the condition being irrelevant to measuring the cell of the second RAT ; and in response to both the first and second criteria being met, skipping a measurement of the cell of the second RAT.

20. An apparatus for wireless communication, comprising: a request receiving module configured to receive, using a first radio access technology (RAT), a request to measure a cell of a second RAT ; a criteria determination module configured to determine whether a first criterion and a second criterion are met, wherein the first criterion is based on a mode of the apparatus, in the mode, the apparatus supporting the second RAT dependent on the first RAT, and wherein the second criterion is based on a condition triggering an event associated with the second RAT, the condition being irrelevant to measuring the cell of the second RAT ; and a measurement module configured to, in response to both the first and second criteria being met, skip a measurement of the cell of the second RAT.