Method performed by a user equipment and user equipment

Abstract

The application provides a method executed by a user equipment (UE), comprising: when a first condition is met, checking the validity of a version of a first system message by the UE in an RRC idle state and / or an RRC inactive state; and if the version of the first system message saved by the UE is invalid, acquiring the first system message by the UE.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and more specifically, to a method performed by a user equipment and a corresponding user equipment. Background Technology

[0002] With the standardization and gradual commercialization of 5G, its application scenarios are becoming increasingly diversified. Firstly, in industrial wireless sensor scenarios, there are numerous types of sensors with varying uses. Some of these sensors require high reliability and low latency or high bandwidth, some require ultra-low cost and ultra-long battery life, while others fall somewhere in between. These devices can be considered as reduced-performance NR devices. Secondly, with the planning and development of smart cities, video surveillance and information collection are widely used, and wireless devices used in these applications also exhibit similar characteristics to the reduced-performance NR devices mentioned above. Finally, many wearable devices, such as smartwatches, smart bracelets, and health monitoring devices, also possess the characteristics of reduced-performance NR devices. For this type of reduced-performance NR device, existing standards are not adequately able to support them in achieving optimal performance requirements.

[0003] For the reasons mentioned above, in March 2021, at the 3rd Generation Partnership Project (3GPP) RAN#91e plenary session, a work project on reduced-capability NR devices (see non-patent literature: RP-210918 Revised WID on support of reduced-capability NR devices) was approved for version 17. This work project identifies industrial wireless sensors, video surveillance, and wearable devices as applicable scenarios. One of the goals of this work project is to study power savings and battery life enhancement for reduced-capability NR devices, including reducing downlink control channel (PDCCH) eDRX (extended discontinuous reception) in RRC inactive or idle states, and relaxing Radio Resource Management (RRM) measurements for stationary devices.

[0004] In December 2019, at the 3rd Generation Partnership Project (3GPP) RAN#86 plenary meeting, the work project for power saving enhancements in Release 17 (see non-patent literature: RP-193239 New WID: UE Power Saving Enhancements) was approved. The latest version of this work project is found in non-patent literature: RP-200938 Revised WID_UE Power Saving Enhancements for NR_Change. This work project primarily investigates how terminals can save power in RRC idle and RRC inactive states. One of the goals of this work project is to share TRS / CSI-RS timings used in connected states with UEs in idle and inactive states. Based on the work project for reduced-capability NR devices in Release 17 (see non-patent literature: RP-210918 Revised WID on support of reduced-capability NR devices), the solutions in the power saving enhancements work project in Release 17 are by default applicable to reduced-capability NR devices.

[0005] To conserve energy, the UE employs idle and inactive eDRX modes. Simultaneously, to further conserve energy, the device can measure TRS / CSI-RS in both idle and inactive states based on network configuration. This invention discusses the related issues of system message verification, acquisition, and updating in this scenario. Summary of the Invention

[0006] To address at least some of the aforementioned problems, the present invention provides a method and a user equipment that can promptly acquire valid system messages carrying idle and inactive TRS / CSI-RS configurations, preventing the UE from missing PO due to invalid TRS / CSI-RS measurements, while also saving power consumption.

[0007] According to the present invention, a method executed by a user equipment (UE) is proposed, comprising: when the UE is in an RRC idle state and / or an RRC inactive state, verifying the version validity of a first system message when a first condition is met; and if the version of the first system message stored by the UE is invalid, then the UE obtains the first system message.

[0008] Preferably, the first condition includes at least one of the following:

[0009] The UE has the ability to measure TRS / CSI-RS in idle and inactive states;

[0010] The extended discontinuous reception eDRX configuration of the UE meets the requirements;

[0011] The UE is configured with RRC proprietary signaling to use resources for TRS / CSI-RS in idle and inactive states; and

[0012] The validity of the first system message saved during the last verification of the UE has exceeded one system message modification cycle.

[0013] Preferably, the eDRX configuration of the UE meets at least one of the following requirements:

[0014] The RRC inactive state eDRX parameter has been configured;

[0015] The configured RRC inactive state eDRX period is longer than the system message modification period;

[0016] The RRC idle state eDRX parameters have been configured; and

[0017] The configured RRC idle state eDRX period is longer than the system message modification period.

[0018] Preferably, the first system message is a system message that includes the idle state and inactive state TRS / CSI-RS configuration.

[0019] Preferably, the time point at which the UE verifies the version validity of the first system message includes at least one of the following:

[0020] The UE wakes up from extended discontinuous eDRX reception;

[0021] Before the UE wakes up from the eDRX;

[0022] The UE measures idle and inactive TRS / CSI-RS before;

[0023] When the UE measures idle state and inactive state TRS / CSI-RS; and

[0024] The UE listens for the paging time PO before that.

[0025] Preferably, the time point at which the UE obtains the first system message includes at least one of the following:

[0026] At the beginning of the next system message modification cycle;

[0027] At the start of the next extended discontinuous eDRX system message acquisition cycle; and

[0028] Immediately obtain the first system message.

[0029] In addition, according to the present invention, a method executed by a user equipment (UE) is proposed, comprising: the UE, which is in an RRC idle state and / or an RRC inactive state, listening to the paging time PO during the paging time window PTW; and when the UE satisfies a first condition, if the UE receives a short message that sets a system message change indication, the UE updates a first system message.

[0030] Preferably, the first condition includes at least one of the following:

[0031] The UE has the ability to measure TRS / CSI-RS in idle and inactive states;

[0032] The extended discontinuous reception eDRX configuration of the UE meets the requirements;

[0033] The UE is configured with RRC proprietary signaling to use resources for TRS / CSI-RS in idle and inactive states; and

[0034] The validity of the first system message saved during the last verification of the UE has exceeded one system message modification cycle.

[0035] Preferably, the time point at which the UE obtains the first system message includes at least one of the following:

[0036] At the beginning of the next system message modification cycle;

[0037] At the boundary of the next extended discontinuous eDRX system message acquisition cycle; and

[0038] Immediately obtain the first system message.

[0039] Furthermore, according to the present invention, a user equipment is provided, comprising: a processor; and a memory storing instructions; wherein the instructions, when executed by the processor, perform the methods described above.

[0040] According to the present invention, it is possible to obtain effective system messages carrying idle and inactive TRS / CSI-RS configurations in a timely manner, thereby preventing the UE from missing PO due to invalid TRS / CSI-RS measurements and saving power consumption. Attached Figure Description

[0041] Figure 1 This is a flowchart illustrating a method performed by a user equipment according to Embodiment 1 of the present invention.

[0042] Figure 2 This is a flowchart illustrating a method performed by a user equipment according to Embodiment 2 of the present invention.

[0043] Figure 3 This is a block diagram representing the user equipment (UE) involved in this invention. Detailed Implementation

[0044] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the present invention should not be limited to the specific embodiments described below. Furthermore, for the sake of simplicity, detailed descriptions of well-known technologies not directly related to the present invention have been omitted to prevent confusion in understanding the present invention.

[0045] The following describes some of the terms involved in this invention. The specific meanings of the terms can be found in the latest 3GPP standard specifications, such as TS38.300, TS38.331, TS36.300, TS36.331, etc. Unless otherwise indicated, the terms involved in this invention have the meanings described below.

[0046] UE: User Equipment

[0047] NR: New Radio, a next-generation wireless technology

[0048] MAC: Medium Access Control

[0049] MAC CE: MAC control element

[0050] RRM: Radio Resource Management

[0051] RRC: Radio Resource Control

[0052] RRC_CONNECTED: RRC connection state

[0053] RRC_INACTIVE: RRC inactive state

[0054] RRC_IDLE: RRC idle state

[0055] RAN: Radio Access Network, Wireless Access Layer

[0056] PDCCH: Physical downlink control channel

[0057] PBCH: Physical broadcast channel

[0058] eDRX: Extended DRX (Discontinuous Receiver)

[0059] PO: Paging Occasion

[0060] BWP: Bandwidth Part

[0061] SFN: System Frame Number

[0062] H-SFN: Hyper SFN (Super Frame Number)

[0063] PTW: Paging Time Window

[0064] PDU: Protocol Data Unit

[0065] SSB: SS / PBCH block, Synchronization Signal / Physical Broadcast Channel Block

[0066] CSI: Channel-state information

[0067] CSI-RS: CSI reference signal, Channel State Information Reference Signal

[0068] TRS: Tracking Reference Signal

[0069] DCI: Downlink Control Information

[0070] C-RNTI: Temporary Identifier for Cellular Wireless Network

[0071] P-RNTI: Paging RNTI, Temporary Identifier for Paging Wireless Network

[0072] PDCCH: Physical Downlink Control Channel

[0073] In this invention, the network, base station, and RAN can be used interchangeably. The network can be a Long Term Evolution (LTE) network, a New Radio Access Technology (New RAT, NR) network, an enhanced Long Term Evolution (eLTE) network, or other networks defined in subsequent 3GPP evolution versions.

[0074] In this invention, the User Equipment (UE) may refer to the NR device with reduced capabilities described in the background art, the NR device with the ability to measure TRS / CSI-RS in idle or inactive states described in the background art, or other types of NR devices or LTE devices.

[0075] The related technologies of the present invention are described below.

[0076] In NR, the system message modification cycle is a periodic period containing several SFNs, configured by the system message. If the base station needs to change the system message, it can instruct the UE to change the system message within a certain modification cycle, and then broadcast the changed system message at the beginning of the next modification cycle. The system message change indication is contained in a Short Message, which can be sent to each PO. The Short Message consists of fields in DCI format 1_0 used to indicate system message related information, scrambled with P-RNTI and transmitted on the PDCCH. In RRC_IDLE or RRC_INACTIVE states, the UE listens to its own PO in each DRX cycle to obtain the system message change indication. The UE's own PO is a subset of all POs calculated based on the UE_ID. In RRC_CONNECTED state, if the UE is provided with a common search space, and this common search space contains pagingSearchSpace, searchSpaceSIBl, and searchSpaceOtherSystemInformation configurations on the active BWP, then the UE listens to any PO at least once in each modification cycle to obtain the system message change indication. If the UE receives a Short Message carrying a system message change indication, the UE will apply the system message acquisition procedure at the beginning of the next modification cycle to obtain the updated system message.

[0077] In LTE, UEs in RRC_IDLE mode can be configured with eDRX, which allows for longer discontinuous reception, thus saving power. For UEs configured with eDRX periods, system messages are updated according to the eDRX system message acquisition period. The eDRX system message acquisition period consists of several H-SFNs, and the boundary of this period is a fixed H-SFN number. UEs configured with eDRX periods can also be configured with a PTW (Paging Time Shift) period. The PTW is a paging listening time within the eDRX period. Within each eDRX period, the UE only needs to listen to the PO (Position Message) within the PTW. If the system message changes within an eDRX system message acquisition period, the base station can carry an eDRX system message change indication in the paging message or DCI (Distributed Core Information). If the UE's eDRX period is longer than the system message modification period, the UE obtains the eDRX system message change indication by listening to the PO. If this indication is received, the UE applies the system message acquisition procedure at the beginning of the next eDRX system message acquisition period to obtain the updated system message. To avoid access failures caused by using outdated system messages, if the UE's eDRX period is longer than the system message modification period, and at least one system message modification period boundary has passed since the UE last verified the validity of the system message, the UE needs to verify the validity of the system message before establishing or restoring the RRC connection. If the system message saved by the UE is invalid, the system message retrieval procedure is executed.

[0078] In NR, the CSI-RS downlink channel state information reference signal is transmitted by the base station. Terminals can receive this reference signal for time-frequency tracking and measurement in RRC connected state. CSI-RS can be configured for periodic, semi-continuous, and aperiodic transmission. TRS (Tracking Reference Signal) is a type of CSI-RS used for tracking reference signals.

[0079] In RRC idle and inactive states, the UE needs to listen to the PO (Point of Purchase) to detect if it has a paging message. To receive a paging message, the UE needs to wake up before the PO time and receive an SSB (Search Service Bus) for synchronization. In poor radio resource conditions, the UE may need to receive multiple SSBs before synchronization, forcing it to wake up much earlier. In the power-saving enhancement project for version 17, by sharing the existing TRS / CSI-RS timings (used only in connected state) with idle and inactive UEs, the UE can perform time-frequency tracking via TRS / CSI-RS, thus achieving faster synchronization. This way, the UE can receive a paging message without waking up too early, achieving energy savings. Simultaneously, the connected state CSI-RS can also be shared with idle and inactive UEs for measurements in these states. The TRS / CSI-RS used for idle and inactive states can be configured via system messages.

[0080] After introducing idle and inactive eDRX in NR, one possibility is to adopt the system message verification and update processing mechanism under the RRC_IDLE state eDRX in LTE, as described above.

[0081] According to research on NR devices with reduced capabilities, these devices may have the ability to measure TRS / CSI-RS in both idle and inactive states. The TRS / CSI configuration used for idle and inactive states may change, thus altering the system messages carrying that configuration. With eDRX configured, if the UE only obtains updated system messages at the boundaries of the eDRX system message acquisition cycle based on the eDRX system message change indication, the UE may use an invalid TRS / CSI-RS configuration to measure TRS / CSI-RS for idle and inactive states. This could cause the UE to miss PO (Positioning Point) synchronization or fail to achieve faster synchronization and reduce power consumption by measuring TRS / CSI-RS.

[0082] This invention enables timely acquisition of valid system messages carrying idle and inactive TRS / CSI-RS configurations when the UE is simultaneously configured with eDRX and has idle and inactive TRS / CSI-RS measurement capabilities. This avoids the UE missing PO due to invalid TRS / CSI-RS measurements and saves power consumption.

[0083] The following describes in detail several embodiments of the present invention that address the above-mentioned problems.

[0084] Example 1

[0085] Figure 1This is a flowchart illustrating a method performed by a user equipment according to Embodiment 1 of the present invention.

[0086] like Figure 1 As shown, this embodiment includes steps 101 and 103.

[0087] Optionally, in step 101, when a UE in RRC_IDLE and / or RRC_INACTIVE satisfies the first condition, it verifies the validity of the first system message version.

[0088] Optionally, the first condition includes one or more of the following (in any combination of "and" or "or" where applicable):

[0089] 1) The UE has the capability to measure TRS / CSI-RS in both idle and inactive states;

[0090] 2) The UE's eDRX configuration meets the requirements;

[0091] 3) The UE is configured with resources for TRS / CSI-RS in idle and inactive states by RRC dedicated signaling;

[0092] 4) The validity of the first system message saved by the UE has exceeded one system message modification cycle since the last verification;

[0093] Optionally, the eDRX configuration may meet the requirements, including but not limited to the following:

[0094] 1) RRC_IDLE and / or RRC_INACTIVE eDRX parameters (such as eDRX period, offset, etc.) are configured;

[0095] 2) The configured RRC_IDLE and / or RRC_INACTIVE eDRX period is greater than the system message modification period.

[0096] Optionally, the first system message refers to a system message that contains the idle and inactive TRS / CSI-RS configurations. It can be an extension of a system message in the prior art or a new system message.

[0097] Optionally, the time point at which the UE verifies the first system message may include one or more of the following possibilities (in any combination of "AND" or "OR" where applicable):

[0098] 1) The UE wakes up from eDRX;

[0099] 2) Before the UE wakes up from eDRX;

[0100] 3) Before the UE measures the idle state and inactive state TRS / CSI-RS;

[0101] 4) When the UE measures the idle state and inactive state TRS / CSI-RS;

[0102] 5) Before the UE listens to the PO.

[0103] Optionally, the methods for the UE to verify the validity of the first system message version include, but are not limited to:

[0104] 1) The UE determines the validity of the stored valueTag of the first system message version;

[0105] 2) The UE determines the validity of the first system message by verifying whether the saved version has been stored for more than 3 hours.

[0106] It should be noted that if the si-SchedulingInfo (this IE is in System Message 1) carries the ValueTag of the first system message, the UE verifies the valueTag in the saved version of the first system message and this valueTag. If the two valueTag values ​​are not equal, it indicates that the first system message version is invalid; otherwise, it indicates that the first system message is valid. A saved version of the first system message older than 3 hours is invalid, and one saved within 3 hours is valid.

[0107] Optionally, in step 103, if the first system message version saved by the UE is invalid, the UE obtains the first system message.

[0108] The UE can obtain the first system message at the beginning of the next system message modification period, or at the beginning of the next eDRX system message acquisition period, or immediately. If the UE obtains the first system message immediately, it first needs to obtain system message 1. If the si-SchedulingInfo in system message 1 contains the scheduling information for the first system message, the UE will immediately obtain the first system message based on that scheduling information.

[0109] Example 2

[0110] Figure 2 This is a flowchart illustrating a method performed by a user equipment according to Embodiment 2 of the present invention.

[0111] like Figure 2 As shown, this embodiment includes steps 201 and 203.

[0112] Optionally, in step 201, the UE in RRC_IDLE and / or RRC_INACTIVE listens to PO during PTW.

[0113] During PTW, the UE may listen to PO in the following ways:

[0114] 1) Monitor your own Product Object (PO) according to the DRX cycle;

[0115] 2) Listen to any PO at least once during each system message modification cycle;

[0116] 3) If the UE is provided with a common search space, and that common search space contains the pagingSearchSpace, searchSpaceSIBl, and searchSpaceOtherSystemInformation configurations on the active BWP, then the UE listens to any PO at least once in each system message modification cycle.

[0117] Optionally, in step 201, a UE in RRC_IDLE and / or RRC_INACTIVE listens for a PO during PTW when a first condition is met. The first condition, as described in Embodiment 1, involves listening for a PO during PTW as described above.

[0118] Optionally, in step 203, when the UE meets the first condition, if the UE receives a Short Message message which sets a system message change indication, the UE updates the first system message.

[0119] The system message change indication includes either the systemInfoModification indication or the first system message change indication. The system message change indication is set by setting the corresponding bit position, for example, to 1.

[0120] The UE can obtain the first system message at the beginning of the next system message modification period, at the boundary of the next eDRX system message acquisition period, or immediately. If the next system message modification period is not within the PTW window, the UE may not acquire the first system message. In other words, the UE can acquire the first system message at the beginning of the next system message modification period that is within the PTW. To acquire the first system message immediately, the UE first needs to acquire system message 1. If the si-SchedulingInfo in system message 1 contains the scheduling information for the first system message, the UE will acquire the first system message immediately based on that scheduling information.

[0121] Example 3

[0122] This embodiment describes the scenario where eDRX and idle / inactive TRS / CSI-RS are not used simultaneously.

[0123] Optionally, if the UE has the capability to measure TRS / CSI-RS in both idle and inactive states, and RRC_IDLE and / or RRC_INACTIVE eDRX are not configured, then the UE needs to obtain the first system message in both idle and inactive states.

[0124] Optionally, if the UE has the capability to measure TRS / CSI-RS in idle and inactive states, and RRC_IDLE and / or RRC_INACTIVE eDRX are not configured, and the UE receives a Short Message in which a system message change indication is set, then the UE obtains the first system message at the beginning of the next system message modification period.

[0125] The system message change indication includes either the systemInfoModification indication or the first system message change indication. The system message change indication is set by setting the corresponding bit position, for example, to 1.

[0126] Figure 3 This is a simplified structural block diagram of the user equipment (UE) involved in this invention. Figure 3 As shown, the user equipment UE300 includes a processor 301 and a memory 302. The processor 301 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 302 may include, for example, volatile memory (such as random access memory, RAM), a hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory. Program instructions are stored on the memory 302. When executed by the processor 301, these instructions can perform the methods described in detail herein, executed by the user equipment.

[0127] A program running on a device according to the invention can be a program that enables a computer to perform the functions of embodiments of the invention by controlling a central processing unit (CPU). The program, or the information processed by the program, can be temporarily stored in volatile memory (such as random access memory, RAM), hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory systems.

[0128] Programs used to implement the functions of the various embodiments of the present invention can be recorded on a computer-readable recording medium. The corresponding functions can be implemented by causing a computer system to read and execute the programs recorded on the recording medium. The term "computer system" here can refer to a computer system embedded in the device, and may include an operating system or hardware (such as peripheral devices). "Computer-readable recording medium" can be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a short-time dynamic storage program recording medium, or any other computer-readable recording medium.

[0129] Various features or functional modules of the devices used in the above embodiments can be implemented or executed by circuits (e.g., monolithic or multi-chip integrated circuits). Circuits designed to perform the functions described in this specification may include general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of the above devices. A general-purpose processor may be a microprocessor, or any existing processor, controller, microcontroller, or state machine. The above circuits may be digital circuits or analog circuits. In cases where advancements in semiconductor technology have led to new integrated circuit technologies that replace existing integrated circuits, one or more embodiments of the present invention may also be implemented using these new integrated circuit technologies.

[0130] Furthermore, the present invention is not limited to the embodiments described above. Although various examples of the embodiments have been described, the present invention is not limited thereto. Fixed or non-mobile electronic devices installed indoors or outdoors can be used as terminal devices or communication devices, such as AV equipment, kitchen equipment, cleaning equipment, air conditioners, office equipment, vending machines, and other household appliances.

[0131] As described above, embodiments of the present invention have been described in detail with reference to the accompanying drawings. However, the specific structure is not limited to the above embodiments, and the present invention also includes any design modifications that do not depart from the spirit of the invention. Furthermore, various modifications can be made to the present invention within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included within the technical scope of the present invention. In addition, components with the same effects described in the above embodiments can be substituted for each other.

Claims

1. A method executed by a user equipment (UE), comprising: When the UE is in the RRC idle state and / or the RRC inactive state, it verifies the version validity of the first system message when the first condition is met; as well as If the version of the first system message stored by the UE is invalid, then the UE retrieves the first system message. The first condition includes at least one of the following: The UE has the ability to measure TRS / CSI-RS in idle and inactive states; The extended discontinuous reception eDRX configuration of the UE meets the requirements; The UE is configured with RRC proprietary signaling to use resources for TRS / CSI-RS in idle and inactive states; and The validity of the first system message saved during the last verification of the UE has exceeded one system message modification cycle.

2. The method according to claim 1, wherein, The UE's eDRX configuration must meet at least one of the following requirements: The RRC inactive state eDRX parameter has been configured; The configured RRC inactive state eDRX period is longer than the system message modification period; The RRC idle state eDRX parameters have been configured; and The configured RRC idle state eDRX period is longer than the system message modification period.

3. The method according to claim 1, wherein, The first system message is a system message that contains the idle state and inactive state TRS / CSI-RS configuration.

4. The method according to claim 1, wherein, The time point at which the UE verifies the version validity of the first system message includes at least one of the following: The UE wakes up from extended discontinuous eDRX reception; Before the UE wakes up from the eDRX; The UE measures idle and inactive TRS / CSI-RS before; When the UE measures idle state and inactive state TRS / CSI-RS; and The UE listens for the paging time PO before that.

5. The method according to claim 1, wherein, The time point at which the UE obtains the first system message includes at least one of the following: At the beginning of the next system message modification cycle; At the start of the next extended discontinuous eDRX system message acquisition cycle; and Immediately obtain the first system message.

6. A method performed by a user equipment (UE), comprising: The UE in the RRC idle state and / or RRC inactive state listens for the paging time PO during the paging time window PTW; as well as When the UE meets the first condition, if the UE receives a short message indicating a system message change, then the UE updates the first system message. The first condition includes at least one of the following: The UE has the ability to measure TRS / CSI-RS in idle and inactive states; The extended discontinuous reception eDRX configuration of the UE meets the requirements; The UE is configured with RRC proprietary signaling to use resources for TRS / CSI-RS in idle and inactive states; and The validity of the first system message saved during the last verification of the UE has exceeded one system message modification cycle.

7. The method according to claim 6, wherein, The time point at which the UE obtains the first system message includes at least one of the following: At the beginning of the next system message modification cycle; At the boundary of the next extended discontinuous eDRX system message acquisition cycle; and Immediately obtain the first system message.

8. A user equipment, comprising: processor; as well as Memory, which stores instructions; The instructions, when executed by the processor, perform the method according to any one of claims 1 to 7.

Images