New Radio (NR) split-bearer round-trip time (RTT) delay optimization

Abstract

A method for wireless communication performed by a user equipment (UE) includes sending an uplink message to a first base station associated with a first radio access technology (RAT). The method further includes sending one or more scheduling requests (SRs) to a second base station associated with a second RAT to trigger a Connected Mode Discontinuous Receive (CDRX) ON period. The method also includes receiving a downlink message from the second base station during the CDRX ON period in response to sending the uplink message to the first base station.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Patent Application No. 17 / 464,510, filed September 1, 2021, entitled “RADIO(NR)SPLIT BEARER ROUND TRIPTIME(RTT)LATENCY OPTIMIZATION,” which claims the benefit of U.S. Provisional Patent Application No. 63 / 074,808, filed September 4, 2020, entitled “RADIO(NR)SPLIT BEARER ROUND TRIPTIME(RTT)LATENCY OPTIMIZATION,” the disclosures of which are expressly incorporated herein by reference in their entirety. Technical Field

[0003] Various aspects of this disclosure generally relate to wireless communications, and more specifically to techniques and apparatus for improving the round-trip time (RTT) latency of split bearers in 5G New Radio (NR). Background Technology

[0004] Wireless communication systems are widely deployed to provide a variety of communication services such as telephone, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies capable of supporting multi-user communication by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access technologies include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems, and Long Term Evolution (LTE). LTE / LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard issued by the 3rd Generation Partnership Project (3GPP). Narrowband (NB) Internet of Things (IoT) and Enhanced Machine-Type Communications (eMTC) are sets of enhancements to LTE for machine-type communications.

[0005] A wireless communication network may include multiple base stations (BSs) that can support communication for multiple user equipments (UEs). UEs can communicate with base stations (BSs) via downlinks and uplinks. A "downlink" (or "forward link") refers to the communication link from the BS to the UE, and an "uplink" (or "backward link") refers to the communication link from the UE to the BS. As will be described in more detail, a BS may be referred to as a Node B, Evolved Node B (eNB), gNB, Access Point (AP), Radio Headend, Transmit and Receive Point (TRP), New Radio (NR) BS, 5G Node B, etc.

[0006] The aforementioned multiple access technologies have been adopted in various communication standards to provide a common protocol enabling different user equipment to communicate at the municipal, national, regional, and even global levels. New Radio (NR), also known as 5G, is a collection of enhancements to the LTE mobile standard issued by the 3rd Generation Partnership Project (3GPP). NR is designed to better support mobile broadband internet access by improving spectrum efficiency, reducing costs, improving service, utilizing new spectrum, and using Orthogonal Frequency Division Multiplexing (OFDM) with a Cyclic Prefix (CP) on the downlink (DL), and using CP-OFDM and / or SC-FDM (e.g., also known as Discrete Fourier Transform Extended OFDM (DFT-s-OFDM)) on the uplink (UL), as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technologies and better integration with other open standards such as carrier aggregation. Summary of the Invention

[0007] In one aspect of this disclosure, a method for conducting wireless communication at a user equipment (UE) includes sending an uplink message to a first base station associated with a first radio access technology (RAT). The method further includes sending one or more scheduling requests (SRs) to a second base station associated with a second RAT to trigger a Connected Mode Discontinuous Receive (CDRX) ON period. The method also includes receiving a downlink message from the second base station during the CDRX ON period in response to sending the uplink message to the first base station.

[0008] Another aspect of this disclosure relates to an apparatus for performing wireless communication at a UE. The apparatus includes components for transmitting an uplink message to a first base station associated with a first RAT. The apparatus also includes components for transmitting one or more SRs to a second base station associated with a second RAT to trigger a CDRX ON period. The apparatus further includes components for receiving a downlink message from the second base station during the CDRX ON period in response to transmitting the uplink message to the first base station.

[0009] In another aspect of this disclosure, a non-transitory computer-readable medium having non-transitory program code thereon for wireless communication at a UE is disclosed. The program code is executed by a processor and includes program code for sending an uplink message to a first base station associated with a first RAT. The program code also includes program code for sending one or more SRs to a second base station associated with a second RAT to trigger a CDRX ON period. The program code further includes program code for receiving a downlink message from the second base station during the CDRX ON period in response to sending the uplink message to the first base station.

[0010] Another aspect of this disclosure relates to a UE. The UE includes a processor, a memory coupled to the processor, and an instruction stored in the memory and operable, when executed by the processor, to cause the UE to send an uplink message to a first base station associated with a first RAT. Execution of the instruction also causes the UE to send one or more SRs to a second base station associated with a second RAT to trigger a CDRX ON period. Execution of the instruction further causes the UE to receive downlink messages from the second base station during the CDRX ON period in response to sending an uplink message to the first base station.

[0011] In one aspect of this disclosure, a method for wireless communication by a first base station associated with a first RAT includes receiving an uplink message transmitted by a UE from a second base station of a second RAT. The method further includes receiving one or more SRs from the UE during a CDRX OFF period of the UE. The method further includes transmitting a downlink message in response to the uplink message during a CDRX ON period of the UE, the CDRX ON period occurring after a first scheduled CDRX ON period scheduled according to the CDRX cycle of the first RAT and before a second scheduled CDRX ON period.

[0012] Another aspect of this disclosure relates to an apparatus for wireless communication by a first base station associated with a first RAT. The apparatus includes components for receiving uplink messages transmitted by a UE from a second base station of a second RAT. The apparatus also includes components for receiving one or more SRs from the UE during a CDRX OFF period of the UE. The apparatus further includes components for transmitting downlink messages in response to the uplink messages during a CDRX ON period of the UE, the CDRX ON period occurring after a first scheduled CDRX ON period scheduled according to the CDRX cycle of the first RAT and before a second scheduled CDRX ON period.

[0013] In another aspect of this disclosure, a non-transitory computer-readable medium having non-transitory program code recorded thereon for wireless communication at a first base station associated with a first RAT is disclosed. The program code is executed by a processor and includes program code for receiving uplink messages transmitted by a UE from a second base station of a second RAT. The program code also includes program code for receiving one or more SRs from the UE during a CDRX OFF period of the UE. The program code further includes program code for transmitting downlink messages in response to the uplink messages during a CDRX ON period of the UE, the CDRX ON period occurring after a first scheduled CDRX ON period scheduled according to the CDRX period of the first RAT and before a second scheduled CDRX ON period.

[0014] Another aspect of this disclosure relates to a first base station associated with a first RAT. The first base station includes a processor, a memory coupled to the processor, and instructions stored in the memory and operable when executed by the processor to cause the first base station to receive uplink messages sent by the UE from a second base station of a second RAT. Execution of the instructions further causes the first base station to receive one or more SRs from the UE during a CDRX OFF period of the UE. Execution of the instructions further causes the first base station to send downlink messages in response to the uplink messages during a CDRX ON period of the UE, the CDRX ON period occurring after a first scheduled CDRX ON period scheduled according to the CDRX period of the first RAT and before a second scheduled CDRX ON period.

[0015] The aspects generally include methods, apparatus, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, wireless communication equipment, and processing systems, as described generally with reference to and through accompanying drawings and specifications.

[0016] The features and technical advantages of the examples according to this disclosure have been outlined quite extensively above in order to provide a better understanding of the following detailed description. Additional features and advantages will be described. The disclosed concepts and specific examples can be readily used as the basis for modifications or designs of other structures for achieving the same purpose as this disclosure. Such equivalent structures do not depart from the scope of the appended claims. The features of the concepts disclosed herein (both their organization and manner of operation, and the associated advantages) will be better understood from the following description when considered in conjunction with the accompanying drawings. Each drawing is provided for illustrative and descriptive purposes and not as a limitation of the claims. Attached Figure Description

[0017] To gain a detailed understanding of the features of this disclosure, a more specific description can be obtained by referring to aspects some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only certain aspects of this disclosure and should not be considered as limiting its scope, as other equally valid aspects are permissible in this specification. The same reference numerals in different drawings may identify the same or similar elements.

[0018] Figure 1 This is a conceptual map showing a block diagram of an example of a wireless communication network according to various aspects of this disclosure.

[0019] Figure 2 This is a conceptual map showing an example of a base station communicating with a user equipment (UE) in a wireless communication network according to various aspects of this disclosure.

[0020] Figure 3This is a timing diagram illustrating an example of a delay test across a radio access network (RAN).

[0021] Figure 4 This is a timing diagram illustrating an example of a cross-RAN latency test.

[0022] Figure 5 This is a timing diagram illustrating an example of an independent delay test.

[0023] Figure 6 This is a timing diagram illustrating an example of a cross-RAN delay test according to various aspects of this disclosure.

[0024] Figure 7 This is a flowchart illustrating an example process performed by a UE, for example, according to various aspects of this disclosure.

[0025] Figure 8 This is a flowchart illustrating an example process performed by a base station, for example, according to various aspects of this disclosure. Detailed Implementation

[0026] Various aspects of this disclosure are described more fully below with reference to the accompanying drawings. However, this disclosure may be embodied in many different forms and should not be construed as limited to any particular structure or function presented throughout this disclosure. Rather, these aspects are provided to make this disclosure thorough and complete, and to fully convey the scope of this disclosure to those skilled in the art. Based on these teachings, those skilled in the art will understand that the scope of this disclosure is intended to cover any aspect of this disclosure, whether implemented independently of or in combination with any other aspect of this disclosure. For example, any number of the aspects set forth may be used to implement an apparatus or practice. Furthermore, the scope of this disclosure is intended to cover such apparatuses or methods in which other structures, functions, or structures, functions other than those set forth in this disclosure, or different from those set forth in this disclosure, are used. It should be understood that any aspect of the disclosure herein may be implemented by one or more elements of the claims.

[0027] Several aspects of a communication system will now be presented with reference to various devices and techniques. These devices and techniques will be described in detail below and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively, “elements”). These elements can be implemented using hardware, software, or a combination thereof. Whether these elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the entire system.

[0028] It should be noted that while the terms commonly associated with 5G and subsequent wireless technologies may be used to describe the aspects, the aspects of this disclosure may be applied to communication systems based on other generations, such as and including 3G and / or 4G technologies.

[0029] In some deployment scenarios, a base station associated with a first radio access technology (RAT) (such as a 5G New Radio (NR) base station) can be deployed as a supplementary node (e.g., a secondary node (SN)) to another base station associated with a second RAT (such as a Long Term Evolution (LTE) base station). In such a deployment scenario, the base station associated with the second RAT can be deployed as a primary node (MN). This deployment type can also be referred to as a non-standalone (NSA) deployment using dual connectivity between RAT base stations (such as LTE and 5G NR base stations). For ease of explanation, 5G NR can be referred to as NR. Non-standalone deployments can use different bearer types, such as primary cell group (MCG) bearers, secondary cell group (SCG) bearers, and split bearers. For split bearers, services (such as user plane services) can be separated between the base station associated with the first RAT (e.g., LTE) and the base station associated with the second RAT (e.g., NR).

[0030] In some cases, user equipment (UE) can measure network latency based on the round-trip time (RTT) of data packets. When using split bearers, the RRT can be the time difference from sending a packet via an uplink channel associated with a first RAT to receiving a response via a downlink channel associated with a second RAT. In some examples, the RRT can be tested via a ping latency test across the radio access network (RAN). In conventional systems, the latency associated with split bearers is greater than the latency associated with standalone deployments. The increase in latency can be based on the delay of connection mode discontinuous reception (CDRX) cycles (such as NR CDRX cycles). Aspects of this disclosure relate to reducing latency for services across split bearers.

[0031] Figure 1This is a schematic diagram illustrating a network 100 in which aspects of this disclosure may be practiced. Network 100 may be a 5G or NR network or some other wireless network, such as an LTE network. Wireless network 100 may include multiple BS 110s (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with a user equipment (UE) and may also be referred to as a base station, NR BS, Node B, gNB, 5G Node B (NB), access point, Transmit and Receive Point (TRP), etc. Each BS may provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to the coverage area of ​​a BS and / or the BS subsystem serving that coverage area, depending on the context in which the term is used.

[0032] A BS can provide communication coverage for macrocells, picocells, femtocells, and / or other types of cells. A macrocell can cover a relatively large geographical area (e.g., a radius of several kilometers) and can allow unrestricted access by UEs with a service subscription. A picocell can cover a relatively small geographical area and can allow unrestricted access by UEs with a service subscription. A femtocell can cover a relatively small geographical area (e.g., a home) and can allow restricted access by UEs associated with that femtocell (e.g., UEs in a Closed Subscriber Group (CSG)). A BS used for macrocells can be referred to as a macro BS. A BS used for picocells can be referred to as a pico BS. A BS used for femtocells can be referred to as a femtocell BS or a home BS. Figure 1 In the example shown, BS 110a can be a macro BS of macro cell 102a, BS 110b can be a pico BS of pico cell 102b, and BS 110c can be a femto BS of femto cell 102c. A BS can support one or more (e.g., three) cells. The terms “eNB,” “base station,” “NR BS,” “gNB,” “TRP,” “AP,” “Node B,” “5G NB,” and “cell” are used interchangeably.

[0033] In some respects, the cell may not necessarily be stationary, and the geographical area of ​​the cell may move depending on the location of the mobile BS. In some respects, BSs may interconnect with each other and / or interconnect with one or more other BSs or network nodes (not shown) in the wireless network 100 using any suitable transport network through various types of backhaul interfaces (such as direct physical connections, virtual networks, etc.).

[0034] The wireless network 100 may also include relay stations. A relay station is an entity that can receive data transmissions from an upstream station (e.g., a BS or a UE) and transmit the data transmissions to a downstream station (e.g., a UE or a BS). A relay station can also be a UE that can relay transmissions for other UEs. Figure 1 In the example shown, relay station 110d can communicate with macro BS 110a and UE 120d to facilitate communication between BS 110a and UE 120d. A relay station can also be referred to as a relay BS, relay base station, relay, etc.

[0035] Wireless network 100 can be a heterogeneous network comprising different types of Base Stations (BSs) (e.g., macro BSs, pico BSs, femto BSs, relay BSs, etc.). These different types of BSs can have different transmit power levels, different coverage areas, and different effects on interference in wireless network 100. For example, macro BSs may have high transmit power levels (e.g., 5 to 40 watts), while pico BSs, femto BSs, and relay BSs may have low transmit power levels (e.g., 0.1 to 2 watts).

[0036] As an example, BS 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and core network 130 can exchange communications via backhaul link 132 (e.g., S1, etc.). Base stations 110 can communicate with each other directly or indirectly (e.g., via core network 130) via other backhaul links (e.g., X2, etc.).

[0037] Core network 130 may be an evolved packet core (EPC), which may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME may be a control node handling signaling between UE 120 and the EPC. All user IP packets can be transmitted through the S-GW, which itself can connect to the P-GW. The P-GW can provide IP address allocation and other functions. The P-GW can connect to the network operator's IP services. The operator's IP services may include the Internet, intranet, IP Multimedia Subsystem (IMS), and packet-switched (PS) streaming services.

[0038] Core network 130 can provide user authentication, access authorization, tracking, IP connectivity, and other access, routing, or mobility functions. One or more of base stations 110 or access node controllers (ANCs) can interface with core network 130 via backhaul links 132 (e.g., S1, S2, etc.) and can perform radio configuration and scheduling for communication with UE 120. In some configurations, the various functions of each access network entity or base station 110 can be distributed across various network devices (e.g., radio headends and access network controllers) or consolidated into a single network device (e.g., base station 110).

[0039] UE120 (e.g., 120a, 120b, 120c) may be distributed throughout the wireless network 100, and each UE may be stationary or mobile. UE may also be referred to as an access terminal, terminal, mobile station, subscriber unit, station, etc. UE may be a cellular phone (e.g., smartphone), personal digital assistant (PDA), wireless modem, wireless communication device, handheld device, laptop computer, cordless phone, wireless local loop (WLL) station, tablet computer, camera, gaming device, netbook, smartbook, ultrabook, medical device or instrument, biometric sensor / device, wearable device (smartwatch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet)), entertainment device (e.g., music or video device or satellite radio), vehicle component or sensor, smart meter / sensor, industrial manufacturing equipment, GPS device, or any other suitable device configured to communicate via wireless or wired media.

[0040] One or more UEs 120 can establish Protocol Data Unit (PDU) sessions for a network slice. In some cases, UE 120 can select a network slice based on an application or subscription service. By serving different network slices for different applications or subscriptions, UE 120 can improve its resource utilization in the wireless network 100 while also meeting the performance specifications of the various applications of UE 120. In some cases, the network slice used by UE 120 can be provided by an AMF (Application Function) associated with one or both of base stations 110 or core networks 130. Figure 1 (Not shown in the image) to provide services. Furthermore, session management for network slices can be performed by the Access and Mobility Management Function (AMF).

[0041] UE 120 may include a latency test module 140. For simplicity, only one UE 120d is shown as including the latency test module 140. The latency test module 140 may send uplink messages to a first base station 110. The first base station 110 may be associated with a first radio access technology (RAT). The latency test module 140 also sends a scheduling request to a second base station 110 associated with a second RAT to trigger an extended connection mode discontinuous reception (CDRX) ON period. The first RAT may be LTE or NR, and the second RAT may be NR. In response to sending uplink messages to the first base station 110, the latency test module 140 also receives downlink messages from the second base station 110 during the extended CDRX ON period.

[0042] Furthermore, one or more base stations 110 (such as the first base station 110) may include a latency test module 138 for receiving uplink messages sent by the UE 120 from the second base station 110 of the second RAT. The latency test module 138 may also receive scheduling requests from the UE 120 during a CDRX ON period of the UE 120. The CDRX ON period may be activated after a first scheduled CDRX ON period scheduled according to the CDRX cycle of the first RAT and before a second scheduled CDRX ON period. The latency test module 138 also sends downlink messages in response to the uplink messages during an extension of the CDRX ON period of the UE 120.

[0043] Some UEs can be considered Machine-Type Communication (MTC) or Evolved or Enhanced Machine-Type Communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, instruments, monitors, location tags, etc., which can communicate with base stations, another device (e.g., remote devices), or certain other entities. For example, a wireless node can provide connectivity to or to a network (e.g., a wide area network such as the Internet or cellular networks) via wired or wireless communication links. Some UEs can be considered Internet of Things (IoT) devices, and / or can be implemented as NB-IoT (Narrowband Internet of Things) devices. Some UEs can be considered Customer Premises Equipment (CPE). UE 120 can be included within a housing that houses the components of UE 120, such as processor components, memory components, etc.

[0044] Typically, any number of wireless networks can be deployed in a given geographical area. Each wireless network can support a specific Radio Access Technology (RAT) and can operate on one or more frequencies. A RAT can also be referred to as a radio technology, air interface, etc. A frequency can also be referred to as a carrier, channel, etc. To avoid interference between wireless networks using different RATs, each frequency can support a single RAT within a given geographical area. In some cases, NR or 5G RAT networks can be deployed.

[0045] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using base station 110 as an intermediary for communicating with each other). For example, UE 120 may use peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (e.g., which may include vehicle-to-vehicle (V2V) protocols, vehicle-to-infrastructure (V2I) protocols, mesh networks, etc.). In this case, UE 120 may perform scheduling operations, resource selection operations, and / or other operations described elsewhere herein as being performed by base station 110. For example, base station 110 may configure UE 120 via downlink control information (DCI), radio resource control (RRC) signaling, media access control-control element (MAC-CE), or via system information (e.g., system information block (SIB)).

[0046] As described above, providing Figure 1 As an example. Other examples may be related to... Figure 1 The descriptions are different.

[0047] Figure 2 A block diagram of a design 200 for base station 110 and UE 120 is shown. Base station 110 and UE 120 can be Figure 1 One of the base stations and one of the UEs. The base station 110 may be equipped with T antennas 234a to 234t, and the UE 120 may be equipped with R antennas 252a to 252r, wherein typically T≥1 and R≥1.

[0048] At base station 110, transmitting processor 220 can receive data for one or more UEs from data source 212, selecting one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indications (CQI) received from the UE, processing (e.g., decoding and modulating) the data for each UE based at least in part on the selected MCS(s), and providing data symbols for all UEs. Reducing the number of MCSs decreases throughput but increases transmission reliability. Transmitting processor 220 can also process system information (e.g., for semi-static resource partitioning information (SRPI), etc.) and control information (e.g., CQI requests, grants, upper-layer signaling, etc.) and provide overhead symbols and control symbols. Transmitting processor 220 can also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signal (PSS) and secondary synchronization signal (SSS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 can perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, and / or reference symbols (if applicable), and can provide T output symbol streams to T modulators (MODs) 232a to 232t. Each modulator 232 can process its corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 can also process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 232a to 232t can be transmitted via T antennas 234a to 234t, respectively. Position coding can be used to generate synchronization signals to convey additional information, according to various aspects described in more detail below.

[0049] At UE 120, antennas 252a to 252r can receive downlink signals from base station 110 and / or other base stations, and can provide the received signals to demodulators 254a to 254r respectively. Each demodulator 254 can adjust (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain an input sample. Each demodulator 254 can also process the input sample (e.g., for OFDM, etc.) to obtain the received symbol. MIMO detector 256 can obtain the received symbol from all R demodulators 254a to 254r, perform MIMO detection on the received symbol (if applicable), and provide the detected symbol. Receiver processor 258 can process (e.g., demodulate and decode) the detected symbol, provide the decoded data for UE 120 to data sink 260, and provide the decoded control information and system information to controller / processor 280. The channel processor can determine the Received Reference Signal Power (RSRP), Received Signal Strength Indication (RSSI), Received Reference Signal Quality (RSRQ), Channel Quality Indication (CQI), etc. In some aspects, one or more components of the UE 120 may be included in the housing.

[0050] On the uplink, at UE 120, the transmitting processor 264 can receive and process data from data source 262 and control information from controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.). The transmitting processor 264 can also generate reference symbols for one or more reference signals. Symbols from the transmitting processor 264 can be pre-encoded (if applicable) by the TXMIMO processor 266, further processed by modulators 254a to 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to base station 110. At base station 110, uplink signals from UE 120 and other UEs can be received by antenna 234, processed by demodulator 254, detected by MIMO detector 236 (if applicable), and further processed by receiving processor 238 to obtain decoded data and control information transmitted by UE 120. The receiver processor 238 can provide decoded data to the data sink 239 and decoded control information to the controller / processor 240. The base station 110 may include a communication unit 244 and communicates with the core network 130 via the communication unit 244. The core network 130 may include a communication unit 294, a controller / processor 290, and a memory 292.

[0051] Figure 2 The controller / processor 240 of base station 110, the controller / processor 280 of UE 120 and / or Figure 2Any other component(s) may perform one or more techniques associated with reducing round-trip time (RTT) latency in cross-RAN latency testing, as described in more detail elsewhere. For example, Figure 2 The base station 110's controller / processor 240, the UE 120's controller / processor 280, and / or any other (multiple) components can execute or bootstrap, for example... Figure 7-8 The operation of processing and / or other processing as described herein. Memory 242 and 282 may store data and program code for base station 110 and UE 120, respectively. Scheduler 246 may schedule the UE for data transmission on the downlink and / or uplink.

[0052] In some aspects, UE 120 may include components for sending uplink messages to a first base station associated with a first RAT; components for sending one or more scheduling requests to a second base station associated with a second RAT to trigger an extended CDRX ON period; and components for receiving downlink messages from the second base station during the extended CDRX ON period in response to sending uplink messages to the first base station.

[0053] In some aspects, base station 110 may include components for receiving uplink messages sent by the UE from a second base station of the second RAT; components for receiving one or more scheduling requests from the UE during a connected mode discontinuous reception (CDRX) ON period; and components for sending downlink messages in response to the uplink messages during an extension of the UE's CDRX ON period.

[0054] Such components may include those with Figure 2 One or more components of the UE 120 or base station 110 described accordingly. As described above, provided... Figure 2 This is just an example. Other examples may be related to... Figure 2 The descriptions are different.

[0055] In some deployment scenarios, a base station associated with a first radio access technology (RAT) (such as a 5G New Radio (NR) base station) can be deployed as a supplementary node (e.g., a secondary node (SN)) to another base station associated with a second RAT (such as a Long Term Evolution (LTE) base station). In such a deployment scenario, the base station associated with the second RAT can be deployed as a primary node (MN). This type of deployment can also be called a non-standalone (NSA) deployment using dual connectivity between RAT base stations (such as LTE and 5G NR base stations). Non-standalone deployments can use different bearer types, such as primary cell group (MCG) bearers, secondary cell group (SCG) bearers, and split bearers. For split bearers, services (such as user plane services) can be split between the base station associated with the first RAT (e.g., LTE) and the base station associated with the second RAT (e.g., NR).

[0056] As described, the UE can measure network latency based on the round-trip time of data packets. For split bearers, the round-trip time can be the time difference from sending a packet via the uplink channel associated with the first RAT to receiving a response via the downlink channel associated with the second RAT. In some examples, the round-trip time can be tested via a cross-RAN ping latency test.

[0057] In some examples, network latency may increase when split bearers are used in a Non-Standalone (NSA) deployment. That is, network throughput may decrease when the UE sends uplink traffic to the LTE base station and receives downlink traffic from the NR base station. In conventional systems, the round-trip time (RTT) of packets in a split bearer is greater than the RTT of packets in a standalone NR deployment (e.g., a non-split bearer deployment). In other words, the latency of a split bearer deployment is higher than that of a standalone NR deployment. The increase in latency can be based on the delay of connection mode discontinuous reception (CDRX) cycles (such as NR CDRX cycles). Aspects of this disclosure relate to reducing the latency of services across split bearers.

[0058] Figure 3 This is a schematic diagram illustrating an example of a cross-RAN ping latency test. (Example) Figure 3 As shown, UE302 can send uplink packet 304 to the first base station 306 at time t1. At time t2, the first base station 306 forwards the uplink packet 304 to the core network 314. The core network 314 can be a reference... Figure 1 An example of the described core network 130. At time t3, core network 314 sends a response 316 to uplink packet 304. (See example...) Figure 3As shown, response 316 is sent to the first base station 306. At time t4, the first base station 306 forwards response 316 to the second base station 310 via backhaul connection 312 (such as the X2 interface). Backhaul connection 312 may be a split bearer. At time t5, the second base station 310 sends response 316 as a downlink packet 308 to the UE 302. In this example, the round-trip time is the difference between time t1 and time t5.

[0059] In one configuration, the first base station 306 is a Long Term Evolution (LTE) base station (e.g., eNB), and the second base station 310 is a New Radio (NR) base station (e.g., gNB). In another configuration, both the first base station 306 and the second base station 310 are NR base stations. In this configuration, the first base station 306 can operate within a first frequency range (FR1) (such as a sub-6 GHz frequency range), while the second base station 310 can operate within a second frequency range (FR2) (such as a millimeter wave (mmW) frequency range). Alternatively, the first base station 306 can operate within FR2, while the second base station 310 can operate within FR1.

[0060] At UE 302, when using split bearer, the NR Packet Data Convergence Protocol (PDCP) module (not shown) can separate PDCP protocol data units (PDUs) for processing by the first radio link control (RLC) module (not shown) of the first RAT (e.g., LTE or NR) and the second RLC module (not shown) of the second RAT (e.g., NR) for separate transmission. In the current example, uplink transmission involves the first RLC module.

[0061] When discontinuous reception (CDRX) of both the radio associated with the first RAT (such as an LTE radio) and the radio associated with the second RAT (such as an NR radio) is enabled at the UE, a round-trip time-based latency test can be performed. As described above, the increased round-trip time can be attributed to the length of the CDRX period (such as the NR CDRX period). Figure 4 This is a timing diagram illustrating an example of a latency test across a radio access network (RAN). For illustrative purposes, Figure 4The cross-RAN latency test illustrated involves cross-RAN ping latency testing. Again, as described, latency testing is not limited to ping testing. Latency testing can be performed by measuring the round-trip time between sending a first data packet to a first RAT (e.g., LTE) and receiving a second data packet from a second RAT (e.g., NR) in response to the first data packet. For example, latency testing can be performed when sending and receiving data for a video game or web browsing application. Furthermore, as described, the first RAT is not limited to an LTE RAT. The first and second RATs can be NRRATs, where the first and second RATs operate in different NR frequency ranges (e.g., FR1 and FR2).

[0062] exist Figure 4 In the example, for UE 402 (such as reference UE 402) Figure 1 The LTE radio 404 and NR radio 406 of the described UE 120 are enabled for CDRX. At time t1a, NR radio 406 enters its first scheduled CDRX ON period. Furthermore, at time t2, LTE radio 404 enters its CDRX ON period. The CDRX ON periods of LTE radio 404 and NR radio 406 may overlap. At time t1b, NR radio 406 transitions to its CDRX OFF period. Figure 4 In the example, LTE radio 404 sends a ping request to LTE base station 408 via the LTE uplink at time t3. In this example, the ping request falls within the CDRXOFF period of NR radio 406. In a conventional system, NR base station 410 (e.g., gNB) waits at time t4a until a second scheduled CDRX ON period to send a corresponding ping response on the NR downlink at time t4b. The first and second scheduled CDRX ON periods can be scheduled based on the configuration of the CDRX cycle of NR radio 406 (e.g., the NRCDRX cycle). The CDRX cycle of NR radio 406 can be referred to as the NR CDRX cycle, and the CDRX cycle of LTE radio 404 can be referred to as the LTE CDRX cycle.

[0063] like Figure 4As shown, the NR CDRX period is 320ms. Therefore, the NR base station 410 waits for 320ms at time t4a until the next configured NR CDRX-ON period (e.g., the second scheduled CDRX ON period). In the best-case scenario, for an NR CDRX period of 320ms, the delay can be 320ms when a ping request is sent at the end of the first scheduled CDRX period (e.g., time t1b). In other scenarios, such as when a ping request is sent during an NR CDRX ON period, the delay can be greater than 320ms. Figure 4 As shown, the LTE CDRX period is 80ms. The CDRX period refers to the time interval between each CDRX ON period. The CDRX ON period can also be called the CDRX wake-up period, while the CDRX OFF period can be called the CDRX sleep period.

[0064] Such as about Figure 4 As described in the example, for a split bearer system, the round-trip time delay can be attributed to the length of the NRCDRX cycle. As described earlier, the round-trip time for an independent test is shorter than that for a cross-RAN test.

[0065] Figure 5 This is a timing diagram illustrating an example of an independent NR latency test. (Example:) Figure 5 As shown, UE502 enters its first scheduled CDRX ON period at time t1, and then enters its CDRX OFF period at time t2. As described, the NRCDRX period is 320ms. Based on this NRCDRX period, the second scheduled CDRX ON period is at time t9. Still, in Figure 5 In the example, when UE502 enters the CDRX OFF period (time t2), UE502 can enter the CDRXON period earlier than its scheduled CDRX ON period to send ping requests. That is, as... Figure 5 As shown in the example, UE 502 enters the CDRX ON period (time t3a) to send a scheduling request to base station 504 at time t3b. A scheduling request (time t3b) can be sent to receive an uplink grant for sending a ping request. The CDRX ON period can be extended in response to sending the scheduling request and receiving the uplink grant. The time period between entering the CDRX OFF period at time t2 and entering the CDRX ON period at time t3a can be less than the CDRX period. For example, the time period between entering the CDRX OFF period at time t2 and entering the CDRX ON period at time t3a can be 15ms.

[0066] like Figure 5As shown, in response to sending a scheduling request at time t3a, UE502 receives an uplink (UL) grant from base station 504 at time t4. As described, the CDRX ON period is extended in response to sending a scheduling request at time t3b. In response to receiving an uplink grant at time t4, the CDRX ON period can be extended by extending the CDRX inactivity timer. Figure 5 In the example, UE 502 extends the CDRX inactivity timer at time t5 and sends a ping request to base station 504 at time t6. The timing of this ping request is not limited to time t6. The ping request can be sent before extending the CDRX inactivity timer (e.g., before time t5), during the time of extending the CDRX inactivity timer (e.g., time t5), or during the period of the CDRX inactivity timer (e.g., between time t5 and t8). In response to sending the ping request at time t6, UE 502 can receive a ping response from base station 504 at time t7. UE 502 can enter the CDRXOFF period at time t8 when the inactivity timer expires. Furthermore, as... Figure 5 As shown in the example, UE 502 can enter the second scheduled CDRX ON period at time t9. Figure 5 In the example, the round-trip time (RTT) is the time difference between sending a ping request at time t6 and receiving a ping response at time t7. Figure 5 In the example, RTT is not delayed due to CDRX cycles.

[0067] According to various aspects of this disclosure, during cross-RAN performance testing with CDRX enabled (such as NR CDRX), the UE may send a scheduling request on the uplink associated with the first RAT (such as NR RAT) before and / or after sending a ping request on the uplink associated with the second RAT (such as LTERAT). The UE may enter the CDRX ON period earlier than scheduled in response to sending this scheduling request. Therefore, due to the earlier CDRX ON period, a ping response can be received earlier.

[0068] Figure 6 This is a timing diagram illustrating an example of a cross-radio access network (RAN) delay test according to various aspects of this disclosure. Figure 6 In the example, for UE 602 (such as reference UE 602), Figure 1 and Figure 2 The LTE radio 604 and NR radio 606 of the described UE 120 are enabled with Connected Mode Discontinuous Reception (CDRX). Furthermore, in Figure 6 In this context, both LTE and NR base stations can serve as references. Figure 1 and Figure 2 An example of base station 110 is described. Furthermore... Figure 6 Using LTE and NR as examples of different RATs, aspects of this disclosure are not limited to LTE and NR. For example, as discussed, the first RAT is not limited to the LTE RAT. The first RAT and the second RAT can be NR RATs, wherein the first RAT and the second RAT operate in different NR frequency ranges (e.g., FRI and FR2). Figure 6 In the example, at time t1a, NR radio 606 enters the first scheduled CDRX ON period. Additionally, at time t2, LTE radio 604 enters the CDRX ON period. The CDRX ON periods of LTE radio 604 and NR radio 606 may overlap. At time t1b, NR radio 606 enters the CDRX OFF period. Figure 6 In the example, LTE radio 604 sends an uplink message to LTE base station 608 via the LTE uplink and L2 interfaces at time t3. In this example, the uplink message falls within the CDRX OFF period. The uplink message may include a ping request, data message, or control signaling. In one configuration, to shorten the round-trip time between sending an uplink message (time t3) and receiving the corresponding downlink message, UE 602 enters the CDRX ON period earlier than it is scheduled to send a scheduling request. In some examples, the scheduling request can be sent during the CDRX OFF period, and depending on the CDRX cycle, the sending of the scheduling request can trigger UE 602 to wake up from the CDRX OFF period before the second scheduled CDRX ON period at time t9. In some examples, both the uplink message and the corresponding downlink message may include data transmission.

[0069] For example, such as Figure 6 As shown, UE 602 sends a scheduling request to NR base station 610 at time t4a, and enters an earlier CDRX ON period at time t4b based on sending the scheduling request. In some other examples, the UE may enter the CDRX ON period first, and then send the scheduling request. At time t5, in response to the scheduling request sent at time t4b, NR radio 606 receives UL clearance from NR base station 610. Sending the scheduling request at time t4b and receiving UL clearance at time t5 extends the inactivity timer at time t6, thus extending the earlier CDRX ON period. In this example, NR radio 606 can receive downlink messages from NR base station 610 at time t7. The round-trip time can be determined based on the time difference between sending the uplink message at time t3 and receiving the downlink message at time t7. Figure 6In the example, the round-trip time is not delayed due to the CDRX cycle. UE602 can enter the CDRX OFF period at time t8 when the inactivity timer expires.

[0070] exist Figure 6 In the example, an LTE scheduling request (time t4a) is sent after UE 602 sends an uplink message on the LTE uplink (time t3). Aspects of this disclosure are not limited to sending the scheduling request after sending an uplink message (e.g., a ping request). In one configuration, the NR scheduling request is sent before UE 602 sends an uplink message via the LTE uplink. That is, the scheduling request can be sent before time t3. In some examples, the scheduling request can be sent both before and after time t3. In another configuration, the NR scheduling request is scheduled based on network latency, scheduling request latency, and inactivity timer duration. For example, the time used to schedule the sending of the scheduling request can be determined as: network latency (e.g., NW_delay_MARGIN) - (scheduling request latency (e.g., SR_delay_time) + inactivity timer duration (e.g., inactivity_timer_duration)).

[0071] Furthermore, as described, UE 602 is not limited to calculating round-trip time based on ping latency tests. Round-trip time can be determined based on the time difference between transmitting data via the LTE uplink and receiving a response to the data transmission on the NR downlink.

[0072] In some cases, depending on the duration of the inactivity timer, if UE 602 does not receive a ping response on the NR downlink in response to a ping request sent on the LTE uplink, UE 602 may issue multiple scheduling requests. In one configuration, UE 602 may continue to extend the CDRX ON period until a ping response is received on the NR downlink.

[0073] As described above, providing Figure 3-6 As an example. Other examples can be related to... Figure 3-6 The descriptions are different.

[0074] Figure 7 This is a flowchart illustrating an example process 700 performed by a user equipment (UE) according to various aspects of this disclosure. The UE may be, respectively, as... Figure 1 , 2 Examples of UE 1l0 or 602 described in section 6. Example processing 700 is an example of improving split bearer RTT latency.

[0075] like Figure 7As shown, in some aspects, processing 700 may include sending an uplink message to a first base station associated with a first radio access technology (RAT) (block 702). For example, a UE (e.g., using antenna 252, DEMOD / MOD 254, TX MIMO 266, transmit processor 264, controller / processor 280, and / or memory 282) may send an uplink message to a first base station (e.g., base station 110 or base station 306) associated with a first RAT (such as LTE or NR). In some aspects, processing 700 may include sending a scheduling request to a second base station associated with a second RAT to trigger a Connected Mode Discontinuous Reception (CDRX) ON period (block 704). For example, a UE (e.g., using antenna 252, DEMOD / MOD 254, TX MIMO 266, transmit processor 264, controller / processor 280, and / or memory 282) may send one or more scheduling requests to a second base station (e.g., base station 110 or base station 608) associated with a second RAT (such as NR). The one or more scheduling requests may be sent before and / or after the uplink message.

[0076] like Figure 7 As shown, in some aspects, processing 700 may include receiving downlink messages from a second base station during a CDRX ON period in response to sending an uplink message to a first base station (block 706). For example, the UE (e.g., using antenna 252, DEMOD / MOD 254, MIMO detector 256, receive processor 258, controller / processor 280, and / or memory 282) may receive downlink messages from a second base station (e.g., base station 110 or base station 608) associated with a second RAT (such as NR). In some examples, the downlink message may include data transmission. Furthermore, the uplink message may also include data transmission.

[0077] Figure 8 This is a flowchart illustrating an example process 800 performed by a base station, such as a first RAT (e.g., NR), according to various aspects of this disclosure. The base station may be located in... Figure 1 , 2 Examples of base stations 110 or 610 described in section 6. Example processing 800 is an example of improving NR split bearer RTT latency.

[0078] like Figure 8As shown, in some aspects, process 800 may include receiving uplink messages sent by the UE from a second base station of the second RAT (block 802). For example, a first base station of the first RAT (e.g., using antenna 234, MOD / DEMOD 232, MIMO detector 236, receive processor 238, controller / processor 240, and / or memory 242) may receive uplink messages sent by the UE from a second base station associated with the second RAT. In some aspects, process 800 may include receiving one or more scheduling requests from the UE during a connection mode discontinuous reception (CDRX) OFF period (block 804). The one or more scheduling requests may be sent by the UE before and / or after the uplink messages. Based on the UE sending one or more scheduling requests, a CDRX ON period may be triggered at the UE. The CDRX ON period may be activated after a first scheduled CDRX ON period scheduled according to the CDRX cycle of the first RAT and before a second scheduled CDRX ON period. For example, a first base station (e.g., using antenna 234, MOD / DEMOD 232, MIMO detector 236, receiver processor 238, controller / processor 240 and / or memory 242) can receive scheduling requests from a UE (e.g., UE 120 or UE 602).

[0079] like Figure 8 As shown, in some aspects, processing 800 may include transmitting a downlink message in response to an uplink message during the CDRX ON period of the UE (block 806). For example, a first base station (e.g., using antenna 234, MOD / DEMOD 232, TX MIMO processor 230, transmit processor 220, controller / processor 240, and / or memory 242) may transmit the downlink message. In some examples, the downlink message may include data transmission. Furthermore, the uplink message may also include data transmission.

[0080] Implementation examples are described in the following numbered clauses:

[0081] Clause 1. A method for wireless communication performed by a UE, comprising: sending an uplink message to a first base station associated with a first radio access technology (RAT); sending one or more scheduling requests (SRs) to a second base station associated with a second RAT to trigger a Connected Mode Discontinuous Receive (CDRX) ON period; and receiving a downlink message from the second base station during the CDRX ON period in response to sending the uplink message to the first base station.

[0082] Clause 2. The method according to Clause 1, wherein one or more SRs include one or both of a first SR sent before the uplink message or a second SR sent after the uplink message.

[0083] Clause 3. The method according to any one of Clauses 1-2 further includes measuring the round-trip time based on the time difference between sending an uplink message and receiving a downlink message.

[0084] Clause 4. The method according to any one of Clauses 1-3, wherein: the uplink message includes a ping request; and the downlink message includes a ping response.

[0085] Clause 5. The method according to any one of Clauses 1-3, wherein the uplink message includes data transmission and the downlink message includes data transmission.

[0086] Clause 6. The method according to any one of Clauses 1-5, wherein the first RAT is Long Term Evolution (LTE) and the second RAT is New Radio (NR).

[0087] Clause 7. The method according to any one of Clauses 1-5, wherein the first RAT is a new radio (NR) operating in a first frequency range, and the second RAT is an NR operating in a second frequency range.

[0088] Clause 8. The method described in Clause 7, wherein: the first frequency range is FR1 and the second frequency range is FR2; or the first frequency range is FR2 and the second frequency range is FR1.

[0089] Clause 9. The method according to any one of Clauses 1-8 further comprises: transitioning from a first scheduled CDRX ON period to a CDRX OFF period before sending an uplink message; entering an earlier CDRX ON period before a second scheduled CDRX ON period to send an SR of one or more SRs; sending the SR of the one or more SRs during the earlier CDRX ON period; and receiving an uplink grant during the earlier CDRX ON period.

[0090] Clause 10. The method described in Clause 9 further includes extending the earlier CDRX ON period in response to sending the one or more SRs.

[0091] Clause 11. The method described in Clause 10, wherein extending the earlier CDRX ON period includes extending the inactive timer.

[0092] Clause 12. The method according to Clause 9 further includes scheduling a first scheduled CDRX ON period and a second CDRX ON period according to the CDRX cycle.

[0093] Clause 13. The method according to any one of Clauses 1-12 further includes scheduling the transmission of the one or more SRs as a function of network latency, scheduling request latency, and the duration of an inactive timer.

[0094] Clause 14. The method according to any one of Clauses 1-13, wherein the UE supports split bearer configuration.

[0095] Clause 15. A method performed by a first base station associated with a first radio access technology (RAT), comprising: receiving an uplink message sent by a user equipment (UE) from a second base station of a second RAT; receiving one or more scheduling requests (SRs) from the UE during a connection mode discontinuous reception (CDRX) OFF period; and sending a downlink message in response to the uplink message during a CDRX ON period of the UE, the CDRX ON period occurring after a first scheduled CDRX ON period scheduled according to the CDRX cycle of the first RAT and before a second scheduled CDRX ON period.

[0096] Clause 16. The method according to Clause 15, wherein one or more SRs include one or both of a first SR sent before an uplink message or a second SR sent after a downlink message.

[0097] Clause 17. The method according to any one of Clauses 15-16, wherein: the uplink message includes a ping request; and the downlink message includes a ping response.

[0098] Clause 18. The method according to any one of Clauses 15-16, wherein the uplink message includes data transmission and the downlink message includes data transmission.

[0099] Clause 19. The method according to any one of Clauses 15-18 further includes extending the CDRX ON period based on receiving one or more SRs.

[0100] Clause 20. The method according to any one of Clauses 15-19, wherein: the first base station operates in non-standalone (NSA) mode or new radio (NR) dual connectivity (NRDC) mode; and the first base station supports split bearer configuration.

[0101] Clause 21. The method according to any one of Clauses 15-20, wherein the first RAT is New Radio (NR) and the second RAT is Long Term Evolution (LTE).

[0102] Clause 22. The method according to any one of Clauses 15-20, wherein the first RAT is a new radio (NR) operating in a first frequency range, and the second RAT is an NR operating in a second frequency range.

[0103] Article 23. The method described in Article 22, wherein: the first frequency range is FR1 and the second frequency range is FR2; or the first frequency range is FR2 and the second frequency range is FR1.

[0104] Clause 24. A user equipment (UE) includes a processor, a memory coupled to the processor, and instructions stored in the memory and operable when executed by the processor to cause the UE to perform any of Clauses 1 to 14.

[0105] Clause 25. An apparatus configured for wireless communication, comprising at least one component for performing any one of Clauses 1 to 14.

[0106] Clause 26. A computer program comprising code for causing a device to perform any one of Clauses 1 to 14.

[0107] Clause 27. The first base station includes a processor, a memory coupled to the processor, and instructions stored in the memory and operable when executed by the processor to cause the UE to perform any of Clauses 15 to 23.

[0108] Clause 28. An apparatus configured for wireless communication, comprising at least one component for performing any one of Clauses 15 to 23.

[0109] Clause 29. A computer program comprising code for causing a device to perform any one of Clauses 15 to 23.

[0110] The foregoing disclosure provides explanations and descriptions, but is not intended to be exhaustive or to limit the aspects to the exact form disclosed, but rather to be modified and varied based on the foregoing disclosure, or to be modified and varied from practice in these aspects.

[0111] As used herein, the term "component" is intended to be interpreted broadly as hardware, firmware, and / or a combination of hardware and software. As used herein, a processor is implemented as hardware, firmware, and / or a combination of hardware and software.

[0112] The threshold is used to describe several aspects. As used in this article, depending on the context, satisfying the threshold can refer to a value that is greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, etc.

[0113] It is evident that the described systems and / or methods can be implemented in various forms of hardware, firmware, and / or combinations of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods does not limit these aspects. Therefore, the operation and behavior of the systems and / or methods are described without reference to specific software code—it should be understood that software and hardware can be designed to implement the systems and / or methods, at least in part, based on the description herein.

[0114] Although specific combinations of features are listed in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of the aspects. In fact, many of these features can be combined in ways not specifically listed in the claims and / or not disclosed in the specification. Although each dependent claim listed below may directly refer to only one claim, the disclosure of the aspects includes a combination of each dependent claim with each of the other claims in the claims. The phrase “at least one” referring to a series of items means any combination of those items (including single members). As an example, “at least one of a, b, or c” is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination with multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other order of a, b, and c).

[0115] Unless explicitly stated otherwise, no element, action, or instruction used herein should be construed as essential or necessary. Furthermore, as used herein, the terms “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more.” Additionally, as used herein, the terms “set” and “group” are intended to include one or more items (e.g., related items, unrelated items, a combination of related and unrelated items, etc.) and may be used interchangeably with “one or more.” If only one item is intended to be used, the phrase “only one” or similar language is used. Furthermore, as used herein, the terms “has,” “have,” “having,” etc., are intended as open-ended terms. Additionally, unless explicitly stated otherwise, the phrase “based on” means “at least partially based on.”

Claims

1. A method for wireless communication performed by a user equipment (UE), comprising: Send an uplink message to a first network entity associated with the first radio access technology (RAT); Entering connection mode to discontinuously receive CDRX ON periods to send one or more scheduling requests SR to the second network entity associated with the second RAT; During the CDRX ON period, the one or more SRs are sent to the second network entity associated with the second RAT; as well as In response to sending the uplink message to the first network entity, a downlink message is received from the second network entity during the CDRX ON period.

2. The method according to claim 1, wherein, The one or more SRs include one or both of a first SR sent before the uplink message or a second SR sent after the uplink message.

3. The method according to claim 1 further includes measuring the round-trip time based on the time difference between sending the uplink message and receiving the downlink message.

4. The method according to claim 1, wherein: The uplink message includes a ping request; and The downlink messages include ping responses.

5. The method according to claim 1, wherein, The uplink message includes data transmission, and the downlink message includes data transmission.

6. The method according to claim 1, wherein, The first RAT is Long Term Evolution (LTE), and the second RAT is New Radio (NR).

7. The method according to claim 1, wherein, The first RAT is a new radio NR operating in a first frequency range, and the second RAT is an NR operating in a second frequency range.

8. The method according to claim 7, wherein: The first frequency range is FR1 and the second frequency range is FR2; or The first frequency range is FR2 and the second frequency range is FR1.

9. The method of claim 1, wherein the CDRX ON period is after the first scheduled CDRX ON period and before the second scheduled CDRX ON period, and the method further comprises: Before sending the uplink message, the process transitions from the first scheduled CDRX ON period to the CDRX OFF period; as well as In response to sending the one or more SRs to the second network entity, an uplink permission is received during the CDRX ON period prior to the second scheduled CDRX ON period.

10. The method of claim 9, further comprising extending the CDRXON period in response to sending the one or more SRs.

11. The method according to claim 10, wherein, Extending the CDRX ON period includes extending the inactivity timer.

12. The method of claim 9 further includes scheduling the first scheduled CDRX ON period and the second scheduled CDRX ON period according to the CDRX cycle.

13. The method of claim 1, further comprising scheduling the transmission of the one or more SRs as a function of network latency, scheduling request latency, and inactivity timer duration.

14. The method according to claim 1, wherein, The UE supports split bearer configuration.

15. A method performed by a first network entity associated with a first radio access technology (RAT), comprising: Receive uplink messages sent by the user equipment (UE) from the second network entity of the second RAT; During the period when the UE's connection mode is discontinuously receiving CDRX ON, one or more scheduling requests SR are received from the UE; as well as During the CDRX ON period of the UE, a downlink message in response to the uplink message is sent, the CDRX ON period occurring after a first scheduled CDRX ON period scheduled according to the CDRX cycle of the first RAT and before a second scheduled CDRX ON period.

16. The method according to claim 15, wherein, The one or more SRs include one or both of a first SR sent before the uplink message or a second SR sent after the uplink message.

17. The method of claim 15, wherein: The uplink message includes a ping request; and The downlink messages include ping responses.

18. The method according to claim 15, wherein, The uplink message includes data transmission, and the downlink message includes data transmission.

19. The method of claim 15, further comprising determining to extend the CDRX ON period based on receiving the one or more SRs.

20. The method of claim 15, wherein: The first network entity operates in either non-standalone NSA mode or new radio NR dual-connectivity NRDC mode; and The first network entity supports split bearer configuration.

21. The method according to claim 15, wherein, The first RAT is New Radio (NR), and the second RAT is Long Term Evolution (LTE).

22. The method according to claim 15, wherein, The first RAT is a new radio NR operating in a first frequency range, and the second RAT is an NR operating in a second frequency range.

23. The method according to claim 22, wherein: The first frequency range is FR1 and the second frequency range is FR2; or The first frequency range is FR2 and the second frequency range is FR1.

24. A user equipment (UE), comprising: processor, Memory coupled to the processor; as well as Instructions stored in the memory, and which, when executed by the processor, are operable to cause the UE to: Send an uplink message to a first network entity associated with the first radio access technology (RAT); Entering connection mode to discontinuously receive CDRX ON periods to send one or more scheduling requests SR to the second network entity associated with the second RAT; During the CDRX ON period, the one or more SRs are sent to the second network entity associated with the second RAT; as well as Based on sending the uplink message to the first network entity, a downlink message is received from the second network entity during the CDRX ON period.

25. The UE according to claim 24, wherein, The execution of the instruction also enables the UE to measure the round-trip time based on the time difference between sending the uplink message and receiving the downlink message.

26. The UE according to claim 24, wherein, The one or more SRs include one or both of a first SR sent before the uplink message or a second SR sent after the uplink message.

27. The UE according to claim 24, wherein, The uplink message includes data transmission, and the downlink message includes data transmission.

28. The UE according to claim 24, wherein: The uplink message includes a ping request; and The downlink messages include ping responses.

29. The UE according to claim 24, wherein, The CDRX ON period is after the first scheduled CDRX ON period and before the second scheduled CDRX ON period, and the execution of the instruction also causes the UE to: Before sending the uplink message, the process transitions from the first scheduled CDRX ON period to the CDRX OFF period; as well as In response to sending the one or more SRs to the second network entity, an uplink permission is received during the CDRX ON period prior to the second scheduled CDRX ON period.

30. A first network entity associated with a first radio access technology (RAT), comprising: processor, Memory coupled to the processor; as well as Instructions stored in the memory, and which, when executed by the processor, are operable to cause the first network entity to: Receive uplink messages sent by the user equipment (UE) from the second network entity of the second RAT; During the period when the UE's connection mode is discontinuously receiving CDRX ON, one or more scheduling requests SR are received from the UE; as well as During the CDRX ON period of the UE, a downlink message in response to the uplink message is sent, the CDRX ON period occurring after a first scheduled CDRX ON period scheduled according to the CDRX cycle of the first RAT and before a second scheduled CDRX ON period.

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