Propagation Delay Compensation

Abstract

The time synchronization accuracy of UE may not meet the requirements of time-sensitive services in some cases (e.g., the distance between UE and gNB is > 200 meters). The provided solution ensures that UE supporting time-sensitive services can meet the synchronization accuracy requirements and ensure the continuity of time-sensitive services.

Description

Technical Field

[0001] The present application relates to the field of communication systems, and more specifically, to a method and device for propagation delay compensation (PDC) and cell (re)selection. Background Art

[0002] Wireless communication systems such as third-generation (3G) mobile phone standards and technologies are well known. The Third Generation Partnership Project (3GPP) has developed such 3G standards and technologies. Generally speaking, third-generation wireless communications have been developed to support macro-cell mobile phone communications, and communication systems and networks have developed towards broadband and mobile systems. In a cellular wireless communication system, user equipment (UE) is connected to a radio access network (RAN) via a wireless link. The RAN includes a group of base stations that provide wireless links to UEs located in the cells covered by the base stations and include an interface to the core network (CN), which has the function of controlling the entire network. It can be understood that the RAN and CN each perform corresponding functions related to the entire network. The 3rd Generation Partnership Project has developed the so-called Long Term Evolution (LTE) system, the Evolved Universal Mobile Telecommunication System Territorial Radio Access Network (E-UTRAN), for a mobile access network of one or more macro cells supported by base stations called eNodeB or eNB (evolved NodeB). More recently, LTE has further evolved into the so-called 5G or New Radio (NR) system, in which one or more cells are supported by base stations called gNBs.

[0003] Time Sensitive Network (TSN) is a set of standards developed by IEEE (IEEE802.1Q TSN standard) to define the mechanism of time-sensitive data transmission and accurate timing reference on wired Ethernet network (IEEE 802.3 Ethernet standard). This accurate reference timing comes from a central clock source, called Grand Master, which is distributed through a series of hops between nodes based on Precision Time Protocol (PTP), namely IEEE 1588 Precision Time Protocol.

[0004] As stated in SA1 TR 22.804 and TR 22.821 and documented as a key topic in TR 23.734 (Key Topic #3), one of the key requirements for NR systems is to support some form of interworking with Time Sensitive Networks (TSN), such as Figure 1 shown.

[0005] RAN2#103bis stipulates that the NR system acts as a "black box" in the TSN network. In this way, TSN provides accurate reference timing to the NR system, such as Figure 2 As shown in Figure 1. The NR system is essentially what the IEEE calls a "Boundary Clock (BC)". As a master clock for all connected nodes (represented by the dashed box), the NR system is able to distribute TSN-derived accurate timing to all UEs in the system. In addition, the NR system is able to compensate for time drift caused by delays in the air interface, which is a topic discussed in NR Industrial Internet of Things (IIoT) related research. The NR system timing maintained by the UE is distributed as PTP packets to all devices connected to its Ethernet port.

[0006] Propagation Delay Compensation (PDC) as a key issue of TSN services has been widely discussed in 3GPP meetings. Through analysis, it can be understood that without propagation delay compensation, the achievable time synchronization accuracy will deteriorate with the increase of inter-site distance (ISD), while a larger subcarrier spacing (SCS) can achieve better synchronization accuracy, that is, for sparse gNB layout in a wide area (for example, inter-site distance > 200 meters), without propagation delay compensation, the synchronization accuracy may not meet the requirements of TSN services. The current discussion in the 3GPP meeting pointed out that propagation delay compensation can be performed by the UE. However, whether and how to perform propagation delay compensation for UEs in RRC_CONNECTED state, RRC_IDLE state, RRC_INACTIVE state and UEs in the handover process to support time-sensitive services is still an unresolved issue. Summary of the invention

[0007] A first aspect of the present application provides a propagation delay compensation (PDC) method, comprising: sending a request for propagation delay compensation; receiving a PDC configuration; and performing propagation delay compensation according to the PDC configuration.

[0008] A second aspect of the present application provides a propagation delay compensation (PDC) method, comprising: receiving a request for propagation delay compensation; and sending a PDC configuration for compensating for propagation delay.

[0009] The third aspect of the present application provides a cell (re)selection method, comprising: estimating or measuring the propagation delay between a UE and a base station to generate a measurement result, which includes a propagation delay value relative to the measured base station; selecting a candidate base station from the measured base stations based on the propagation delay value; and connecting to the candidate base station.

[0010] The disclosed method may be implemented in a user equipment or a base station.

[0011] The disclosed methods may be programmed as computer-executable instructions stored in a non-transitory computer-readable medium, which, when loaded into a computer, instructs a processor of the computer to perform the disclosed methods.

[0012] The non-transitory computer readable medium may include at least one of the group consisting of: a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, and a flash memory.

[0013] The disclosed method can be programmed as a computer program product, which enables a computer to perform the disclosed method.

[0014] The disclosed method can be programmed as a computer program, which causes a computer to perform the disclosed method.

[0015] The time synchronization accuracy of UE may not meet the requirements of time-sensitive services in some cases (e.g., the distance between UE and gNB is > 200 meters). The provided solution ensures that UE supporting time-sensitive services can meet the synchronization accuracy requirements and ensure the continuity of time-sensitive services. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or related technologies, the following drawings will be described in the embodiments and briefly introduced as follows. It is obvious that these drawings only present some embodiments of the present application, and those skilled in the art can derive other drawings based on these drawings without making any assumptions.

[0017] Figure 1 Schematic diagram showing the high-level architecture of TSN with 5G.

[0018] Figure 2 Schematic diagram showing the NR system as a black box in a TSN network.

[0019] Figure 3 A flowchart of a method for performing propagation delay compensation when a UE in an RRC_IDLE state or an RRC_INACTIVE state performs measurement, cell (re)selection and random access according to the first embodiment of the present application is shown.

[0020] Figure 4 A flowchart of a method for performing propagation delay compensation when performing measurement and reporting on a UE in an RRC_CONNECTED state according to the second embodiment of the present application is shown.

[0021] Figure 5 A flow chart showing a method for performing propagation delay compensation during a switching process according to a third embodiment of the present application.

[0022] Figure 6 Schematic diagram showing the switching process.

[0023] Figure 7 A block diagram of a system for wireless communication according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings of the present application to describe the embodiments of the present application in detail in terms of technical solutions, structural features, objectives and effects achieved. Specifically, the terms in the embodiments of the present application are only used to describe certain embodiments and are not used to limit the content of the present application.

[0025] This application mainly focuses on whether and how to perform propagation delay compensation (PDC) for user equipment (UE) supporting time-sensitive services (e.g., TSN services, AR, VR, MR, etc.). For UEs in RRC_IDLE state and RRC_INACTIVE state, measurement quantities are defined to evaluate the propagation delay between the UE and the base station (e.g., gNB). Then, the UEs in RRC_IDLE state and RRC_INACTIVE state perform measurements and cell (re)selection taking into account PDC. The measurement quantity may be RSRP / RSRQ / SINR or location (e.g., GPS information), etc. The UE can select the base station that produces the lowest propagation delay based on the measurement results, and start a random access procedure for the selected base station.

[0026] A random access preamble and / or a subset of time-frequency resources (e.g., rach resources) may be allocated to a UE supporting time-sensitive services for random access. Furthermore, the random access preamble (e.g., random access preamble index) and / or time-frequency resources (e.g., subframe number) may be mapped to the propagation delay estimated from the measurement result. That is, the preamble index and / or time-frequency resources (e.g., subframe number) may be derived from the propagation delay estimated from the measurement result of the UE, and conversely, the base station may know the propagation delay between it and the UE from the random access preamble index or / and the time-frequency resources. Another way is that the UE may indicate to the base station whether PDC is required by using a dedicated random access preamble or / and dedicated time-frequency resources for random access, and then the base station may perform PDC on its own or send a configuration related to PDC (PDC value and related measurement configuration) to the UE. The propagation delay can be divided into several levels, and the random access preamble and / or random access resource can be mapped to different levels of propagation delay or different exact values ​​of propagation delay, or a specific algorithm can be used to calculate the random access preamble index or random access resource (e.g., subframe number) from the exact value of the propagation delay or the level of the propagation delay. For example, the random access preamble dedicated to time-sensitive services can be divided into two independent subsets S_with_pdc and S_without_pdc. The UE that needs to perform PDC uses the preamble in the subset S_with_pdc to initiate random access, and then the base station receives the preamble and sends a random access response (Random Access Response, RAR) carrying or carrying the PDC value and / or related measurement and reporting configuration. A similar solution can use time-frequency resources. Before sending RAR, the base station can obtain TSC assistance information (TSCAI) from the core network (CN) or network (NW) (such as 5GC), and calculate the PDC value based on TSCAI and / or preamble code index (or / and subframe number), that is, the PDC value can be calculated based on any one or any combination of TSCAI, preamble code index and subframe number.

[0027] A time-sensitive service-specific message can be defined. Base stations that support time-sensitive services can obtain this message from the core network and broadcast it periodically on specific time-frequency resources. UEs in the RRC_IDLE state and / or RRC_INACTIVE state will read the message, deduce the time when the base station sent the message, and estimate the propagation delay between the base station and the UE. This propagation delay can be used for the UE to perform PDC, and can also be used for the UE to determine which cell to randomly access.

[0028] The UE may also send a PDC request in a random access process with the base station through message 3. For example, the base station receives the PDC request and sends a PDC configuration to the UE through message 4. Then, the UE performs propagation delay compensation.

[0029] For a UE in the RRC_CONNECTED state, measurements and reports related to PDC can be performed according to the PDC configuration from the base station, as is the update process of the timing advance (TA). For a moving UE, the period at which the UE sends a measurement report and / or a PDC request to the base station may depend on the moving speed and / or position of the UE. The faster the UE moves, the shorter the measurement reporting period. The UE can be configured to periodically update the TA or / and to perform in an event-triggered manner. Events and / or thresholds for starting / stopping a timer related to the TA or for initiating a measurement report can be defined for the UE. The UE can be configured by the base station to start or stop PDC, or the UE can send a measurement report / PDC request / TA update request, etc. to the base station, and then the base station signals the UE to start / stop PDC, etc. A default configuration related to PDC can be defined for a UE that supports time-sensitive services in the RRC_CONNECTED state, the RRC_IDLE state, or the RRC_INACTIVE state.

[0030] The measurement result may include RSRP / RSRQ / SINR / TA / distance between UE and base station / UE location information (e.g., GNSS information), etc. The UE may then decide whether to perform PDC or send the measurement result to the base station, and then operate according to the configuration from the base station.

[0031] During the handover process, a PDC request or a measurement report related to PDC may be sent to the source base station, which is then forwarded by the source base station to the target base station. The target base station then sends a PDC configuration / PDC request confirmation to the UE via the source base station, or the target base station may broadcast the information so that the UE can estimate the propagation delay between the UE and the target base station. The behavior of the random access procedure initiated by the handover process is as described in the random access solution mentioned above.

[0032] The advantages achieved by this application include at least the following:

[0033] 1) PDC-related measurement quantities and measurement procedures may be defined for UEs in RRC_IDLE state and / or RRC_INACTIVE state to estimate the propagation delay between the UE and the base station;

[0034] 2) A message dedicated to time-sensitive services can be defined. A base station supporting time-sensitive services can periodically broadcast the message in a specific or dedicated time-frequency resource. The UE can read the message and deduce the time when the message was sent, and then estimate the propagation delay between the UE and the base station;

[0035] 3) The random access preamble can be divided into several subsets, each of which is mapped to a different propagation delay. For different propagation delays, the UE can select a preamble from the corresponding subset for random access;

[0036] 4) Time-frequency resources can be divided into several subsets, each of which is mapped to a different propagation delay. For different propagation delays, the UE can select resources from the corresponding subset for random access;

[0037] 5) The base station receives the preamble and derives the propagation delay between the UE and the base station, and then sends a PDC configuration to configure the UE to perform measurements and reporting, as well as the PDC procedure;

[0038] 6) PDC-related events and thresholds can be defined for UE to perform PDC-related measurements and reports;

[0039] 7) The period of PDC measurement reporting and / or the updating period of time advance may depend on the moving speed of the UE or the location information of the UE, and a relevant mapping relationship may be defined; and

[0040] 8) The above solution is also applicable to the switching process.

[0041] Example 1

[0042] This embodiment focuses on the measurement and cell (re)selection of a UE in the RRC_IDLE state and the RRC_INACTIVE state in consideration of the PDC. A measurement amount may be defined for the RRC_IDLE state and / or the RRC_INACTIVE state to estimate the propagation delay between the UE and the measured base station. The UE may select a cell for random access based on the measurement result.

[0043] The random access preamble (e.g., random access preamble index) and / or time-frequency resource (e.g., subframe number) may be mapped to the propagation delay estimated from the measurement result. The estimated propagation delay may be divided into several levels, and the related schemes include:

[0044] 1) The estimated propagation delay can be divided into two levels, namely, the level that requires PDC and the level that does not require PDC. The random access preamble and / or random access resources are mapped to two different levels of propagation delay. After receiving the random access preamble and / or resources, the base station can decide whether to perform PDC based on the received preamble and / or resources, and the mapping relationship between the preamble and the propagation delay. After that, the base station can perform PDC on its own, or send a PDC-related configuration (PDC value and related measurement configuration) corresponding to the propagation delay level to the UE for the UE to perform PDC, related measurements or / and measurement reporting.

[0045] 2) The estimated propagation delay can be divided into three levels or multiple levels. Random access preambles and / or random access resources are mapped to different levels of propagation delay. The UE or base station selects a random access preamble and / or random access resource corresponding to the estimated propagation delay for the random access procedure. The base station can determine the propagation delay level between the UE and the base station based on the received random access preamble and / or resource. The base station can perform PDC on its own, or send a PDC-related configuration (PDC value and related measurement configuration) corresponding to the propagation delay level to the UE for the UE to perform PDC, related measurements or / and measurement reporting.

[0046] 3) Provide an algorithm or formula to calculate the corresponding random access preamble and / or random access resource based on the estimated propagation delay level. The corresponding random access preamble and / or random access resource are used for the random access procedure between the UE and the base station. After receiving the random access preamble and / or resource, the base station can determine the level of propagation delay based on the received preamble and / or resource and the corresponding algorithm. The base station can perform PDC on its own, or send a PDC-related configuration (PDC value and related measurement configuration) corresponding to the propagation delay level to the UE for the UE to perform PDC, related measurements or / and measurement reporting.

[0047] 4) A mapping or relationship between propagation delay and random access preamble (and / or random access resource) can be established. Specifically, for example, this mapping can be a mapping between the level or value of propagation delay and the random access preamble index (and / or subframe number). Other parameters can also be used to implement this mapping. The base station can determine the level of propagation delay based on the received random access preamble and / or resource, and the mapping or relationship. The base station can perform PDC on its own, or send a PDC-related configuration (PDC value and related measurement configuration) corresponding to the propagation delay level to the UE for the UE to perform PDC, related measurements or / and measurement reporting.

[0048] For random access of the UE, signaling specific to the PDC can be defined for the UE to send PDC requests and related information to the base station, so that the UE can obtain PDC configurations from the base station to perform PDC. The PDC request sent by the UE to the base station can include at least one of the UE's location and / or speed information, subcarrier spacing (SCS), synchronization accuracy, etc.

[0049] A mapping rule for the UE speed and the TA update period (which can be configured by configuring the timeAlignmentTimer) can be defined. That is, the UE reports its speed information to the base station, and the base station determines the TA update period based on the speed information and configures the UE to perform the TA update procedure. Alternatively, the UE is configured with a mapping rule for the moving speed and the TA update period, and then the UE performs the TA update procedure according to the moving speed and the mapping rule. When a timer (e.g., timeAlignmentTimer) expires, the UE performs the TA update procedure by sending a TA update request to the base station.

[0050] A threshold for determining whether to perform PDC can be defined for the UE according to the UE's state and / or related measurement results. For the threshold thresh1, it can be configured by the base station or standardized. If the measurement result (e.g., RARP / RSRQ / SINR) meas_r < (or <=) thresh1, the UE performs the PDC procedure, or if the TA (or the distance between the UE and the base station) Tta > (or >=) thresh1, the UE performs the PDC procedure. Conversely, it can be defined as follows: if the measurement result (e.g., RARP / RSRQ / SINR) meas_r > (or >=) thresh1, the UE stops performing the PDC procedure, or if the TA (or the distance between the UE and the base station) Tta < (or <=) thresh1, the UE stops performing the PDC procedure. Another way is to define another threshold thresh2, where thresh2 < thresh1. If meas_r < (or <=) thresh2, the UE performs PDC, and if meas_r >= (or >) thresh1, the UE stops performing PDC; similarly, if Tta > (or >=) thresh1, the UE performs the PDC procedure, and if Tta < (or <=) thresh2, the UE stops performing PDC.

[0051] When an event meas_r < (or <=) thresh1 (Tta > (or or >=) thresh1, etc.) occurs, the UE can send a PDC request to the base station, and then the base station can send signaling to indicate to the UE to start or stop performing PDC using the value obtained from the base station.

[0052] The UE may perform PDC as a default operation, and then stop performing PDC when instructed by the base station or when a related event occurs. Vice versa, the UE may perform PDC as a default operation, and perform PDC when configured by the base station or triggered by a related event.

[0053] A default value can be defined for PDC, and the UE uses the default value to perform PDC before receiving the PDC configuration from the base station. In addition, PDC can be based on TA, such as T PDC =delta*T TA or / and T PDC_new =T PDC_old +alph, delta can be a constant (e.g., 1 / 2) or configurable, and alph can be obtained from the base station.

[0054] Figure 3 A flowchart of a method for performing propagation delay compensation when a UE in an RRC_IDLE state or an RRC_INACTIVE state performs measurement, cell (re)selection, and random access according to the first embodiment of the present application is shown. Assume that 1) the UE is in an RRC_IDLE state or an RRC_INACTIVE state; and 2) the UE performs measurement and cell (re)selection.

[0055] refer to Figure 3 In step 0, the UE in RRC_IDLE state or RRC_INACTIVE state performs measurement and cell (re)selection. The measurement quantity tsn_delay is defined (for the UE in RRC_IDLE state and / or RRC_INACTIVE state) to estimate the propagation delay between the UE and the base station (or from the UE to the base station, or from the base station to the UE) using, for example, the Reference Signal Receive Power (RSRP). The measurement quantity tsn_delay may be applicable to UEs in RRC_IDLE state and / or RRC_INACTIVE state and / or RRC_CONNECTED state. The measurement result of the UE may be a list of cell identities (CIDs) arranged in the order of tsn_delay, and the UE may select or choose the cell with the largest or smallest tsn_delay value as a candidate cell for random access and connection to the candidate cell. The measurement quantity tsn_delay may be mapped to a timing advance or a distance between the UE and the base station, or any other quantity that may identify the propagation delay between the UE and the base station.

[0056] In step 1, the UE sends the selected random access preamble to the candidate base station. In one embodiment, a subset of random access preambles may be allocated to UEs supporting time-sensitive services (e.g., TSN services) ((pre) configured or / and standardizable, etc.) for random access, and the UE selects one of the preambles and sends it to the base station. In another embodiment, a subset of time-frequency resources may be allocated to UEs supporting time-sensitive services (e.g., TSN services) ((pre) configured or / and standardizable, etc.) for random access, and the UE sends the random access preamble using the resources in the subset.

[0057] In step 2, the base station receives a random access preamble from the UE and sends a random access response (RAR) message to the UE. In one embodiment, the base station receives a dedicated time-sensitive random access preamble from the UE and sends a PDC configuration message included in the RAR message to the UE, where the PDC configuration message includes a propagation delay between the UE and the base station. In another embodiment, the base station receives a random access preamble sent using dedicated time-sensitive time-frequency resources and sends a PDC configuration message included in the RAR message to the UE, where the PDC configuration message includes a propagation delay between the UE and the base station. After receiving the PDC configuration message, the UE may perform propagation delay compensation immediately or in a subsequent step to compensate for the propagation delay between the UE and the base station.

[0058] In step 3, the UE sends a message 3 to the base station. The PDC request message may be included in the message 3 and sent to the base station. The PDC request message may be in the form of a 1-bit field or a field including multiple bits. The PDC request message may include at least one of the UE's location information, speed, time synchronization accuracy, time advance accuracy requirements, etc.

[0059] In step 4, the base station sends a contention resolution message to the UE. The PDC configuration message may be included in the contention resolution message and sent by the base station to the UE. Before generating and sending the PDC configuration message, the base station may obtain the TSCAI from the core network (e.g., 5GC).

[0060] In step 5, the UE performs a PDC procedure.

[0061] In one embodiment, the PDC configuration message sent by the base station may include an information element for the UE to use a timing advance command (TAC) to perform PDC.

[0062] In another embodiment, the PDC configuration message sent by the base station may include a field including one bit or multiple bits, so as to enable the UE to start or stop performing PDC.

[0063] In yet another embodiment, the PDC configuration message sent by the base station may include at least one of the following:

[0064] a) A threshold thresh1 for the UE to start or stop PDC. For example, if T TA >(=)thresh1, UE starts PDC, or / and if T TA <(=)thresh1, UE stops PDC;

[0065] b) Two thresholds thresh1 and thresh2, where thresh1>thresh2, are used for the UE to start or stop PDC. TA >(=)thresh1, the UE starts PDC. If T TA <(=)thresh2, the UE stops performing PDC;

[0066] c) The UE sends a PDC request or updates the PDC value or adjusts the period of the related timer;

[0067] d) Mapping rules between period and speed, etc.

[0068] Example 2

[0069] A UE in the RRC_CONNECTED state may perform measurements and reports configured by a base station (e.g., gNB), as well as the time advance update procedure. For a moving UE, the period for the UE to send measurement reports can be configured based on the moving speed. The faster the UE moves, the shorter the measurement reporting period. Similarly, the faster the UE moves, the shorter the TA update period. A mapping relationship between the moving speed and the period for the UE to perform measurement reporting can be defined for the UE. The relationship between the UE's moving speed and the TA update period can adopt the same design.

[0070] The configuration of measurement report and TA update can take into account the location of UE or the distance between UE and base station. The farther the distance between UE and base station, the shorter the measurement report period. Such design is also applicable to the configuration of TA update.

[0071] Measurement results, such as RARP / RSRQ / SINR, may be considered for the design of measurement reporting and TA update configuration.

[0072] The location information and / or speed information may be sent to the base station and may be included in a measurement report, a PDC request message, or the like.

[0073] As described in Embodiment 1, a threshold for starting or stopping PDC may be defined for the UE.

[0074] Figure 4 The flowchart of the method for performing propagation delay compensation when performing measurement and reporting for a UE in the RRC_CONNECTED state according to the second embodiment of the present application is shown. Assume that 1) both the UE and the base station support time-sensitive services; and 2) the UE is in the RRC_CONNECTED state and is connected to the serving base station.

[0075] refer to Figure 4 In step 0, the base station sends a measurement and reporting configuration to the UE, and the UE receives the measurement and reporting configuration from the base station. Then, the UE performs measurement to generate a measurement report, as shown in step 1a. A measurement quantity may be defined for the UE to estimate the propagation delay from the UE to the base station. The measurement quantity may be at least one of RSRP / RSRQ / SINR / location / speed / distance, etc. For example, RSRP / RSRQ / SINR / location / TA / distance may be used.

[0076] The UE sends a measurement report to the base station, as shown in step 2a, which can be periodic and / or triggered by event / timer expiration. That is, the measurement report can be periodic and / or triggered by an event. Specific events and thresholds can be defined for the UE to perform event-triggered reporting / PDC. The measurement reporting configuration message may include at least one of the mapping relationship between the measurement amount, reporting period, speed / distance / position, etc. and the reporting period, threshold, etc. The measurement report may include speed / position / RSRP / RSRQ / SINR, etc., and may also include TSCAI. The measurement and reporting configuration may include 1 bit or field to instruct the UE to (re)start a timer related to the TA, such as timeAlignmentTimer.

[0077] The UE (re)starts a timer specific to the PDC, as in step 1b. The expiration of the timer or / and the occurrence of an event may trigger the UE to send a PDC request or / and a measurement report to the base station, or update the TA, update the configuration, or start / stop executing PDC. For a UE executing PDC, the expiration of the timer or / and the occurrence of an event may trigger the UE to update the PDC value, or send an update request to the base station, etc.

[0078] The UE sends a PDC request message to the base station, as in step 2b, which may be periodic or / and triggered by an event / timer expiration. The base station receives the measurement report / PDC request from the UE and sends a PDC configuration / PDC request confirmation to the UE, as in step 3. The PDC request confirmation may enable the UE to start / stop performing PDC, or send the latest PDC value to the UE. The base station may generate a new measurement configuration / PDC configuration based on the measurement report / PDC request, for example, the UE may adjust the period of the UE performing measurement reporting / TA update, etc.

[0079] In step 4, the UE receives the PDC request confirmation and performs propagation delay compensation and updates time synchronization. The UE performs PDC using the latest configuration received from the base station.

[0080] Example 3

[0081] This embodiment focuses on propagation delay compensation (PDC) during handover. Figure 5 A flow chart showing a method for performing propagation delay compensation during a switching process according to a third embodiment of the present application. Figure 5 As shown, the PDC request message can be sent to the target base station by the source base station in a handover command (e.g., a HANDOVER REQUEST message), and the PDC request confirmation from the target base station can be sent to the UE by the source base station. In addition, the PDC request message or the measurement report related to the PDC can be included in message 3 and sent to the target base station when the random access procedure initiated by the handover process is performed, and the PDC configuration / request confirmation message can be included in message 4 and sent to the UE. The base station can understand the PDC requirement by receiving a random access preamble transmitted using a dedicated resource or preamble index, and obtain TSCAI from the source base station or core network (CN) or network (NW) (e.g., 5GC), and then send the PDC configuration to the UE.

[0082] UE handover is performed between a source base station (e.g., source gNB) and a target base station (e.g., target gNB). In the following, it is assumed that 1) the UE, the source base station, and the target base station all support time-sensitive services; 2) the UE is in RRC_CONNECTED state and connected to the source base station; 3) the UE is performing measurements and reporting; and 4) the UE is performing a handover procedure.

[0083] refer to Figure 5, the UE sends a PDC request message to the target base station. In one embodiment, the UE sends a PDC request to the source base station, and then the source base station forwards the PDC request message to the target base station, as shown in step 1a. In another embodiment, the UE sends a random access preamble dedicated to time-sensitive services to the target base station or / and sends a random access preamble with a dedicated random access time-frequency resource indicated by the source base station, as shown in step 1b. In yet another embodiment, the UE sends a PDC request in message 3 to the target base station.

[0084] The target base station receives a PDC request from the UE and sends a PDC configuration to the UE. In one embodiment, the target base station receives a PDC request from the UE forwarded by the source base station. In another embodiment, the target base station receives a random access preamble with a preamble and / or random access time-frequency resources indicated by the source base station to indicate that the base station UE supports time-sensitive services. In yet another embodiment, the target base station receives a PDC request in message 3 from the UE.

[0085] The target base station generates a PDC configuration and sends the PDC configuration to the UE via the source base station (step 2a) or directly (step 2b). The target base station can obtain TSCAI from the core network to generate the PDC configuration. In another embodiment, the target base station sends the PDC configuration to the UE together with a contention resolution message (i.e., message 4).

[0086] The UE continues with the remaining steps of the handover procedure and performs PDC-related measurements and PDC procedures.

[0087] like Figure 6 As shown, the switching process mentioned in the present application at least includes a switching preparation phase, a switching execution phase and a switching completion phase.

[0088] In the handover preparation phase, the UE performs measurements and reports according to the measurement and reporting configuration received from the base station or according to the relevant 3GPP standard specifications. When the handover conditions are met, the source base station sends a handover request to a selected or candidate target base station. If the candidate target base station accepts the handover request, the target base station sends a handover request confirmation (positive response) to the source base station. Then, the RAN handover begins.

[0089] According to the configuration from the source base station, such as RrcConnectionReconfiguration, the UE performs a random access procedure initiated by the handover process (e.g., contention-free random access or contention-based random access) during the handover execution phase. Before completing the path switch, the remaining data from the core network will be forwarded by the source base station to the target base station.

[0090] Then, the path switch is performed in the handover completion phase. A path switch request is sent from the target base station to the core network, and once it is confirmed (positive response), data can flow from the UE through the target base station to release the UE context.

[0091] Figure 7 A block diagram of an example system 700 for wireless communication according to an embodiment of the present application is shown. The embodiments described herein may be implemented into the system using any suitably configured hardware and / or software. Figure 7 A system 700 is shown that includes a radio frequency (RF) circuit 710, a baseband circuit 720, a processing unit 730, a memory / storage device 740, a display 750, a camera 760, a sensor 770, and an input / output (I / O) interface 780, which are coupled to each other as shown.

[0092] The processing unit 730 may include circuits such as, but not limited to, one or more single-core or multi-core processors. The processor may include any combination of general-purpose processors and special-purpose processors (e.g., graphics processors and application processors). The processor may be coupled to a memory / storage device and configured to execute instructions stored in the memory / storage device to enable various applications and / or operating systems to run on the system.

[0093] The baseband circuit 720 may include circuits, such as but not limited to one or more single-core or multi-core processors. The processor may include a baseband processor. The baseband circuit may handle various wireless control functions that enable communication with one or more radio networks via RF circuits. The radio control functions may include but are not limited to signal modulation, encoding, decoding, radio frequency shifting, etc. In some embodiments, the baseband circuit may provide communications compatible with one or more wireless technologies. For example, in some embodiments, the baseband circuit may support communications with 5G NR, LTE, Evolved Universal Terrestrial Radio Access Network (EUTRAN) and / or other wireless wide area networks (WMAN), wireless local area networks (WLAN), wireless personal area networks (WPAN). An embodiment in which the baseband circuit is configured to support wireless communications of more than one wireless protocol may be referred to as a multi-mode baseband circuit. In various embodiments, the baseband circuit 720 may include circuits for operating with signals that are not strictly considered to be in the baseband frequency. For example, in some embodiments, the baseband circuit may include circuits for operating with signals having an intermediate frequency, which is between the baseband frequency and the radio frequency.

[0094] The RF circuit 710 can use modulated electromagnetic radiation to achieve communication with a wireless network through a non-solid medium. In various embodiments, the RF circuit may include switches, filters, amplifiers, etc. to facilitate communication with the wireless network. In various embodiments, the RF circuit 710 may include circuits for operating with signals that are not strictly considered to be in radio frequency. For example, in some embodiments, the RF circuit may include circuits for operating with signals having an intermediate frequency, which is between the baseband frequency and the radio frequency.

[0095] In various embodiments, the transmitter circuits, control circuits, or receiver circuits discussed above with respect to user equipment, eNBs, or gNBs may be implemented in whole or in part in one or more of the RF circuits, baseband circuits, and / or processing units. As used herein, "circuitry" may refer to, may be part of, or include an application specific integrated circuit (ASIC), an electronic circuit that executes one or more software or firmware programs, a processor and / or memory (shared, dedicated, or group), a combined logic circuit, and / or other suitable hardware components that provide the described functionality. In some embodiments, the electronic device circuit system may be implemented in one or more software or firmware modules, or the functionality associated with the circuit system may be implemented by one or more software or firmware modules. In some embodiments, some or all of the components of the baseband circuit, processing unit, and / or memory / storage device may be implemented together on a system-on-chip (SOC).

[0096] The memory / storage device 740 can be used to load and store data and / or instructions for the system, for example. The memory / storage device of an embodiment may include any combination of suitable volatile memory (e.g., dynamic random access memory (DRAM)) and / or non-volatile memory (e.g., flash memory). In various embodiments, the I / O interface 780 may include one or more user interfaces and / or peripheral component interfaces, and the one or more user interfaces are designed to enable a user to interact with the system, and the peripheral component interface is designed to enable a peripheral component to interact with the system. The user interface may include, but is not limited to, a physical keyboard or keypad, a touch pad, a speaker, a microphone, etc. The peripheral component interface may include, but is not limited to, a non-volatile memory interface, a universal serial bus (USB) interface, an audio jack, and a power interface.

[0097] In various embodiments, the sensor 770 may include one or more sensing devices for determining environmental conditions and / or location information related to the system. In some embodiments, the sensor may include, but is not limited to, a gyroscope sensor, an accelerometer, a proximity sensor, an ambient light sensor, and a positioning unit. The positioning unit may also be part of or interact with a baseband circuit and / or an RF circuit to communicate with a component of a positioning network (e.g., a global positioning system (GPS) satellite). In various embodiments, the display 750 may include displays such as a liquid crystal display and a touch screen display. In various embodiments, the system 700 may be a mobile computing device, such as, but not limited to, a laptop computing device, a tablet computing device, a netbook, an ultrabook, a smart phone, etc. In various embodiments, the system may have more or fewer components and / or different architectures. Where appropriate, the method described herein may be implemented as a computer program. The computer program may be stored on a storage medium such as a non-transitory storage medium.

[0098] Some embodiments of the present application are combinations of “techniques / processes” that can be adopted in 3GPP specifications to develop terminal products.

[0099] It will be appreciated by those skilled in the art that each unit, algorithm and step described and disclosed in the embodiments of the present application are implemented using electronic hardware or a combination of software and electronic hardware for a computer. Whether these functions are run in hardware or software mode depends on the design requirements of the application conditions and technical solutions. Those skilled in the art can use different ways to implement the functions of each specific application, and this implementation should not exceed the scope of the present application. It will be appreciated by those skilled in the art that the working process of the system, device and unit in the above-mentioned embodiments can be referred to, because the working process of the above-mentioned system, device and unit is basically the same. For ease of description and brevity, these working processes will not be described in detail.

[0100] It should be understood that the systems, devices and methods disclosed in the embodiments of the present application can be implemented in other ways. The embodiments described above are merely illustrative. The division of units is based only on logical functions, and other divisions exist during implementation. Multiple units or components can be combined or integrated into another system. Some features can also be omitted or skipped. On the other hand, the coupling, direct coupling or communication coupling shown or discussed can be indirect coupling through some interfaces, devices or units or electrical, mechanical or other forms of communication coupling.

[0101] The units described as separate components may or may not be physically separate. The units shown may or may not be physical units, i.e., they may be located in one place or distributed over multiple network units. Some or all of the units may be used depending on the purpose of the embodiment. In addition, the functional units in various embodiments may be integrated into one processing unit, or may be physically independent, or two or more units may be integrated into one processing unit.

[0102] If the software functional unit is implemented and sold or used as an independent product, it can be stored in a readable storage medium in a computer. Based on such an understanding, the technical solution proposed in the present application can be essentially or partially implemented in the form of a software product. Alternatively, a part of the technical solution that is beneficial to the prior art can be implemented in the form of a software product. The software product in the computer is stored in a storage medium, including multiple commands for a computing device (such as a personal computer, a server or a network device) to run all or part of the steps disclosed in the embodiment of the present application. The storage medium includes a USB disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a floppy disk or other media capable of storing program code.

[0103] While the present application has been described in connection with what are considered to be the most practical and preferred embodiments, it is to be understood that the application is not limited to the disclosed embodiments, but is intended to cover various arrangements pursuant to the broadest interpretation of the appended claims.

Claims

1. A propagation delay compensation (PDC) method, comprising: Send a request for propagation delay compensation; Receive PDC configuration; and Performing propagation delay compensation according to the PDC configuration; The request includes the location of the user equipment UE, and the speed information, subcarrier spacing, and synchronization accuracy of the UE; the request is sent with time-frequency resources selected from two groups of time-frequency resources corresponding to two propagation delay levels, wherein one group of time-frequency resources indicates that PDC is required, and the other group of time-frequency resources indicates that PDC is not required; the PDC configuration includes a first threshold for deciding to start executing the PDC and a second threshold for deciding to stop executing the PDC, and the first threshold and the second threshold have different values.

2. The method according to claim 1, wherein: Before the sending step, the method further includes: Estimate or measure propagation delay.

3. The method according to claim 1, wherein: Before the sending step, the method further includes: Receive broadcast messages; and A propagation delay is estimated based on the broadcasted message.

4. The method according to claim 1, wherein: The sending step and the receiving step are performed in a random access procedure.

5. The method according to claim 4, wherein: The sending step and the receiving step are performed in at least one of an RRC_IDLE state and an RRC_INACTIVE state.

6. The method according to claim 1, wherein: In the sending step, the request is sent with a random access preamble dedicated to time-sensitive services.

7. The method according to claim 6, wherein: Before the sending step, the method further includes: The random access preamble is selected from a plurality of subsets of random access preambles mapped to different propagation delays.

8. The method according to claim 7, wherein: The random access preamble is selected based on the estimated propagation delay.

9. The method according to claim 1, wherein: In the sending step, the request is sent with a random access preamble selected from two groups of random access preambles corresponding to two propagation delay levels, wherein one group of random access preambles indicates that PDC is required, and the other group of random access preambles indicates that PDC is not required.

10. The method according to claim 1, wherein: In the sending step, the request is sent with a random access preamble selected from a plurality of groups of random access preambles corresponding to different propagation delay levels.

11. The method according to claim 1, wherein: In the sending step, the request is sent with a random access preamble calculated by an algorithm or formula based on a level or value of a propagation delay.

12. The method according to claim 1, wherein: In the sending step, the request is sent with a random access preamble selected according to a mapping or relationship between a propagation delay and a random access preamble.

13. The method according to claim 12, wherein: The mapping is a mapping between the level or value of the propagation delay and a random access preamble index.

14. The method of claim 1, wherein in the receiving step, the PDC configuration corresponds to a level or value of a propagation delay.

15. The method according to claim 1, wherein: In the sending step, the request is sent using time-frequency resources dedicated to time-sensitive services.

16. The method according to claim 15, wherein: Before the sending step, the method further includes: The time-frequency resource is selected from a plurality of subsets of time-frequency resources mapped to different propagation delays.

17. The method according to claim 16, wherein: The time-frequency resources are selected based on the estimated propagation delay.

18. The method according to claim 1, wherein: In the sending step, the request is sent using a time-frequency resource selected from a plurality of groups of time-frequency resources corresponding to different propagation delay levels.

19. The method according to claim 1, wherein: In the sending step, the request is sent using a time-frequency resource calculated using an algorithm or formula based on a level or value of a propagation delay.

20. The method according to claim 1, wherein: In the sending step, the request is sent using time-frequency resources selected based on a mapping or relationship between propagation delay and time-frequency resources.

21. The method according to claim 20, wherein: The mapping is between the level or value of the propagation delay and the subframe number.

22. The method according to claim 1, wherein: In the receiving step, the PDC configuration is received through a random access response RAR.

23. The method according to claim 1, wherein: In the sending step, the request is sent as a message 3 in a random access procedure.

24. The method according to claim 1, wherein: In the receiving step, the PDC configuration is received together with a contention resolution message.

25. The method of claim 1, wherein: The PDC configuration includes an information element to use a timing advance command TAC for the PDC.

26. The method of claim 1, wherein: The PDC configuration contains a bit or a field including several bits to start or stop executing the PDC.

27. The method of claim 1, wherein: The PDC configuration includes at least one of a period of requesting the PDC, a period of executing the PDC, and a period of updating a timing advance TA.

28. The method according to claim 27, wherein: The PDC configuration includes a mapping rule between the period and the moving speed.

29. The method of claim 1, wherein: The sending step and the receiving step are performed in the RRC_CONNECTED state.

30. The method of claim 1, further comprising: Receive measurement and reporting configuration; estimating or measuring the propagation delay, and generating a measurement report based on the measurement and reporting configuration; and The measurement report is sent.

31. The method of claim 1, further comprising: Perform PDC-related measurements and reports according to the PDC configuration.

32. The method of claim 1, further comprising: A time advance TA update procedure is performed according to the PDC configuration.

33. The method of claim 1, further comprising: Perform PDC-related measurements to generate measurement reports; and sending the measurement report, The period of sending the measurement report depends on at least one of the moving speed and the location information.

34. The method of claim 1, wherein: A period of sending the request depends on at least one of the moving speed and the position information.

35. The method of claim 1, further comprising: Update time ahead of TA, The period of updating the TA depends on at least one of the moving speed and the location information.

36. The method of claim 1, wherein: In the receiving step, the PDC configuration is received together with a request confirmation.

37. The method of claim 1, wherein: The receiving step and the sending step are performed during a handover process.

38. The method of claim 1, wherein: In the sending step, the request is sent as a switching command.

39. The method of claim 38, wherein: In the receiving step, the PDC configuration is received together with an acknowledgement of the handover command.

40. The method of claim 1, wherein: In the sending step, in a random access procedure initiated by a handover process, the request is sent with a random access preamble code dedicated to time-sensitive services.

41. The method of claim 1, wherein: In the receiving step, the PDC configuration is received through a random access response RAR in a random access procedure initiated by a handover process.

42. The method of claim 1, wherein: In the sending step, in a random access procedure initiated in a handover process, the request is sent as a message 3, the message 3 is sent to a target device, and a random access is performed to handover to the target device.

43. The method of claim 1, wherein: In the sending step, the PDC configuration is received through a message 4 in a random access procedure initiated by a handover process, and the message 4 is sent from a target device to perform a random access to handover to the target device.

44. The method of claim 1, further comprising: PDC-related measurements are sent during the random access procedure initiated during the handover process.

45. A propagation delay compensation (PDC) method, comprising: receiving a request for propagation delay compensation; and Sending PDC configuration for compensating propagation delay; The request includes the location of the user equipment UE, and the speed information, subcarrier spacing, and synchronization accuracy of the UE; the request is sent with time-frequency resources selected from two groups of time-frequency resources corresponding to two propagation delay levels, wherein one group of time-frequency resources indicates that PDC is required, and the other group of time-frequency resources indicates that PDC is not required; the PDC configuration includes a first threshold for deciding to start executing the PDC and a second threshold for deciding to stop executing the PDC, and the first threshold and the second threshold have different values.

46. ​​The method of claim 45, further comprising: Broadcasts a message used to make propagation delay estimates.

47. The method of claim 45, wherein: The sending step and the receiving step are performed in a random access procedure.

48. The method of claim 45, wherein: In the receiving step, a random access preamble dedicated to a time-sensitive service is received to receive the request.

49. The method of claim 48, wherein: The random access preamble is from a plurality of subsets of random access preambles mapped to different propagation delays.

50. The method of claim 49, wherein: The random access preamble is based on the estimated propagation delay.

51. The method of claim 45, wherein: In the receiving step, time-frequency resources dedicated to time-sensitive services are received to receive the request.

52. The method of claim 51, wherein: The time-frequency resources are from a plurality of subsets of time-frequency resources mapped to different propagation delays.

53. The method of claim 52, wherein: The time-frequency resources are based on estimated propagation delays.

54. The method of claim 45, wherein in the receiving step, the PDC configuration corresponds to a level or value of a propagation delay.

55. The method of claim 45, wherein: In the sending step, the PDC configuration is sent as a random access response RAR.

56. The method of claim 45, wherein: In the receiving step, the request is received via message 3 in a random access procedure.

57. The method of claim 45, wherein: In the sending step, the PDC configuration is sent via a contention resolution message.

58. The method of claim 45, wherein: The PDC configuration includes an information element to use a timing advance command TAC for the PDC.

59. The method of claim 45, wherein: The PDC configuration contains a bit or a field including several bits to start or stop executing the PDC.

60. The method of claim 45, wherein: The PDC configuration includes at least one of a period of requesting the PDC, a period of executing the PDC, and a period of updating a timing advance TA.

61. The method of claim 60, wherein: The PDC configuration includes a mapping rule between the period and the moving speed.

62. The method of claim 45, wherein: The receiving step and the sending step are performed in the RRC_CONNECTED state.

63. The method of claim 45, further comprising: Send measurement and report configuration; and A measurement report generated according to the measurement and reporting configuration is received.

64. The method of claim 45, further comprising: Receive measurement reports related to PDC, The period of receiving the measurement report related to the PDC depends on at least one of the moving speed and the location information.

65. The method of claim 45, wherein: A period of receiving the request depends on at least one of a moving speed and position information.

66. The method of claim 45, further comprising: Provide time ahead of TA, The period of providing the TA depends on at least one of the moving speed and the location information.

67. The method of claim 45, wherein: In the sending step, the PDC is configured to send with a request for confirmation.

68. A user equipment UE, comprising: A processor configured to call and run program instructions stored in a memory to perform the method according to any one of claims 1 to 44.

69. A base station, comprising: A processor configured to call and run program instructions stored in the memory to perform the method described in any one of claims 45 to 67.

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