CN115398855A

CN115398855A - Propagation delay compensation

Info

Publication number: CN115398855A
Application number: CN202080099864.7A
Authority: CN
Inventors: 王和俊; 生嘉
Original assignee: JRD Communication Shenzhen Ltd
Current assignee: JRD Communication Shenzhen Ltd
Priority date: 2020-04-17
Filing date: 2020-04-17
Publication date: 2022-11-25
Also published as: WO2021208082A1

Abstract

The time synchronization accuracy of the UE may not meet the requirements of time sensitive traffic in some cases (e.g., distance between UE and gNB >200 meters). The provided scheme ensures that the UE supporting the time sensitive service can meet the requirement of synchronization accuracy and ensures the continuity of the time sensitive service.

Description

Propagation delay compensation

Technical Field

The present application relates to the field of communication systems, and more particularly, to methods and apparatus for Propagation Delay Compensation (PDC) and cell (re) selection.

Background

Wireless communication systems such as the Third-Generation (3G) mobile telephony standards and technologies are well known, and the Third Generation Partnership Project (3 GPP) has developed such 3G standards and technologies, and in general, third Generation wireless communication has been developed to the extent that it supports macrocell mobile telephony communication, and communication systems and networks have evolved towards broadband and mobile systems. In a cellular Radio communication system, a User Equipment (UE) is connected to a Radio Access Network (RAN) via a Radio link. The RAN comprises a set of base stations (base station) providing radio links to UEs located in the cells covered by the base stations and comprising an interface to a Core Network (CN) having the function of controlling the overall Network. It is to be understood that the RAN and CN each perform corresponding functions with respect to the overall network. The third generation partnership project has developed a so-called Long Term Evolution (LTE) System, i.e., an Evolved Universal Mobile telecommunications System terrestrial Radio Access Network (E-UTRAN), for Mobile Access networks of one or more macro cells supported by base stations called enodebs or enbs (Evolved node bs). Recently, LTE has further evolved towards so-called 5G or New Radio (NR) systems, where one or more cells are supported by base stations called gnbs.

Time Sensitive Network (TSN) is a set of standards developed by IEEE (IEEE 802.1Q TSN standard) for defining mechanisms for Time Sensitive data transmission and accurate timing reference over wired Ethernet (Ethernet Network) networks (IEEE 802.3 Ethernet standard). This accurate reference timing is from a central clock source, called Grand Master, whose distribution through a series of hops between nodes is based on Precision Time Protocol (PTP), IEEE 1588 Precision Time Protocol.

One of the important requirements of NR systems, as indicated in SA1 TR 22.804 and TR 22.821 and noted as critical issues in TR 23.734 (critical issue # 3), is to support some form of interworking with Time Sensitive Networks (TSNs), as shown in fig. 1.

The agreed NR system in RAN2#103bis acts as a "Black Box" in TSN networking. In this manner, the TSN provides an accurate reference timing to the NR system, as shown in fig. 2. The NR system is essentially a so-called "Boundary Clock (BC)" by IEEE, and serves as a master Clock for all connected nodes (indicated by dashed boxes), and is capable of distributing accurate timing derived from the TSN to all UEs in the system. In addition, the NR system can compensate for time drift caused by delay of an air interface, which is a subject 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 ports.

Propagation Delay Compensation (PDC) has been widely discussed in 3GPP meetings as a critical issue for TSN services. It can be understood through analysis that, in the case of no propagation delay compensation, the achievable time synchronization accuracy may deteriorate with the increase of Inter-site distance (ISD), and a larger Subcarrier Spacing (SCS) may obtain better synchronization accuracy, that is, for a sparse gbb layout in a wide area (for example, the Inter-site distance >200 meters), in the case of no propagation delay compensation, the synchronization accuracy may not meet the requirement of the TSN service. The current discussion in 3GPP conferencing indicates that propagation delay compensation can be done by the UE. However, it is still a problem to be solved whether and how to compensate propagation delay for supporting time-sensitive services for the UE in RRC _ CONNECTED state, RRC _ IDLE state, RRC _ INACTIVE state and UE in handover.

Disclosure of Invention

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.

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 to compensate for the propagation delay.

A third aspect of the present application provides a cell (re) selection method, including: estimating or measuring a propagation delay between the UE and the base station to generate a measurement comprising a propagation delay value relative to the measured base station; selecting candidate base stations from the measured base stations according to the propagation delay value; and connecting to the candidate base station.

The disclosed methods may be implemented in a user equipment or a base station.

The disclosed methods can be programmed as computer-executable instructions stored in a non-transitory computer-readable medium that, when loaded into a computer, instruct a processor of the computer to perform the disclosed methods.

The non-transitory computer readable medium may include at least one of the group consisting of: hard disks, CD-ROMs, optical storage devices, magnetic storage devices, read-only memories, programmable read-only memories, erasable programmable read-only memories, electrically erasable programmable read-only memories, and flash memories.

The disclosed methods can be programmed as a computer program product that causes a computer to perform the disclosed methods.

The disclosed methods may be programmed as a computer program that causes a computer to perform the disclosed methods.

The time synchronization accuracy of the UE may not meet the requirements of time sensitive traffic in some cases (e.g., distance between UE and gNB >200 meters). The scheme provided ensures that the UE supporting the time sensitive service can meet the requirement of synchronization accuracy, and ensures the continuity of the time sensitive service.

Drawings

In order to more clearly illustrate the embodiments of the present application or related art, the following drawings are described in the embodiments and are briefly described as follows. It is obvious that these drawings represent only some embodiments of the application and that other drawings can be derived by those skilled in the art from these drawings without presetting them.

FIG. 1 shows a schematic diagram of a TSN high level architecture with 5G.

Fig. 2 shows a schematic diagram of an NR system as a black box in a TSN networking.

Fig. 3 is a flowchart illustrating a method for performing measurement, cell (re) selection, and propagation delay compensation in random access for a UE in an RRC _ IDLE state or an RRC _ INACTIVE state according to a first embodiment of the present application.

Fig. 4 shows a flowchart of a method for performing measurement and reporting delay compensation for a UE in an RRC _ CONNECTED state according to a second embodiment of the present application.

Fig. 5 shows a flow chart of a method for propagation delay compensation during handover according to a third embodiment of the present application.

Fig. 6 shows a schematic diagram of a handover procedure.

Fig. 7 shows a block diagram of a system for wireless communication according to an embodiment of the application.

Detailed Description

The embodiments of the present application will be described in detail with reference to the drawings, along with technical solutions, structural features, and attained objects and effects. In particular, the terminology used in the embodiments of the present application is for the purpose of describing certain embodiments only and is not intended to be limiting of the present application.

The present application focuses mainly on whether and how a User Equipment (UE) supporting time-sensitive traffic (e.g., TSN service, AR, VR, MR, etc.) performs Propagation Delay Compensation (PDC). For UEs in RRC IDLE and RRC INACTIVE states, measurement quantities are defined to evaluate the propagation delay between the UE and the base station (e.g., gNB). Then, the UE in RRC _ IDLE state and RRC _ INACTIVE state performs measurement and cell (re) selection considering PDC. The measurement quantity may be RSRP/RSRQ/SINR or location (e.g., GPS information), etc. The UE may select the base station that produces the lowest propagation delay according to the measurement result, and start a random access procedure for the selected base station.

A UE supporting time sensitive traffic may be assigned a random access preamble and/or a subset of time-frequency resources (e.g., rach resources) for random access. Also, a random access preamble (e.g., random access preamble index) and/or time-frequency resources (e.g., subframe number) may be mapped to the measured estimated propagation delay. That is, the preamble index and/or the time-frequency resource (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 and/or the time-frequency resource. Alternatively, the UE may indicate to the base station whether PDC is required by performing random access using a dedicated random access preamble or/and dedicated time-frequency resources, and then the base station may perform PDC itself or send PDC related configuration (PDC value and related measurement configuration) to the UE. The propagation delay may be divided into several levels, the random access preamble and/or the random access resource may be mapped to different levels of propagation delay or different exact values of propagation delay, or a specific algorithm may be employed to calculate the random access preamble index or the random access resource (e.g. subframe number) from the exact values of propagation delay or the levels of propagation delay. For example, the Random Access preamble dedicated to the time-sensitive service can be divided into two independent subsets S _ with _ PDC and S _ without _ PDC, and the UE that needs to perform PDC initiates Random Access using the preamble in the subset S _ with _ PDC, and then the base station receives the preamble and sends a Random Access Response (RAR) carrying or carrying the PDC value and/or the related measurement and reporting configuration. A similar solution may employ time-frequency resources. Before sending the RAR, the base station may obtain TSC Assistance Information (TSCAI) from a Core Network (Core Network, CN) or a Network (Network, NW) (e.g. 5 GC), and calculate the PDC value from the TSCAI and/or the preamble index (or/and the subframe number), i.e. the PDC value may be calculated from any one or any combination of the TSCAI, the preamble index and the subframe number.

A time sensitive service specific message may be defined, which may be obtained from the core network by the base station supporting the time sensitive service and periodically broadcast on a specific time frequency resource. The UE in RRC IDLE state and/or RRC INACTIVE state reads the message, deduces the time when the base station sends the message, and estimates the propagation delay between the base station and the UE. This propagation delay may be used for PDC by the UE or for the UE to decide which cell to perform random access with.

The UE may also send a PDC request via message 3 during a random access procedure with the base station. For example, the base station receives the PDC request and sends the PDC configuration to the UE via message 4. The UE then performs propagation delay compensation.

For a UE in RRC _ CONNECTED state, PDC related measurements and reporting may be performed according to the PDC configuration from the base station, as well as Timing Advance (TA) update procedure. For a moving UE, the period for which the UE sends measurement reports and/or PDC requests to the base station may depend on the moving speed and/or location of the UE. The faster the UE moves, the shorter the reporting period of the measurement. The UE may be configured to update the TA periodically or/and event-triggered. Events and/or thresholds may be defined for the UE to start/stop a timer related to the TA or to initiate measurement reporting. The UE may be configured by the base station to start or stop PDC taking, or the UE may send a measurement report/PDC request/TA update request, etc. to the base station, which then signals the UE to start/stop PDC taking, etc. A default configuration with respect to PDC may be defined for a UE supporting time-sensitive traffic in RRC _ CONNECTED state, RRC _ IDLE state, or RRC _ INACTIVE state.

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

During handover (handover), a PDC request or a measurement report related to the PDC may be sent to the source base station, and then forwarded by the source base station to the target base station. The target base station then sends a PDC configuration/PDC request acknowledgement to the UE through the source base station, or the target base station may broadcast this information so that the UE can estimate the propagation delay between the UE and the target base station. The behaviour of the random access procedure initiated by the handover procedure is as described for the random access solution mentioned above.

The advantages achieved by the present application include at least the following:

1) PDC-related measurements and measurement procedures may be defined for a UE in RRC IDLE state and/or RRC INACTIVE state to estimate propagation delay between the UE and a base station;

2) Time sensitive service specific messages may be defined. The base station supporting time sensitive services may broadcast the message periodically in specific or dedicated time frequency resources. The UE may read the message and deduce the time at which the message was sent, and then estimate the propagation delay between the UE and the base station;

3) The random access preamble may be divided into several subsets, each subset being mapped to a different propagation delay. For different propagation delays, the UE may select a preamble from the corresponding subset for random access;

4) The time-frequency resources may be divided into several subsets, each subset mapping to a different propagation delay. For different propagation delays, the UE may select resources from the corresponding subset for random access;

5) The base station receives the lead code and deduces the propagation delay between the UE and the base station, and then sends PDC configuration to configure the UE to execute measurement and report, and a PDC program;

6) PDC related events and thresholds may be defined for the UE to perform PDC related measurements and reporting;

7) The period reported by PDC measurement and/or the update period of the time advance may depend on the moving speed of the UE or the location information of the UE, and may define a related mapping relationship; and

8) The above scheme is also applicable to handover procedures.

Example 1

The present embodiment focuses on the measurement and cell (re) selection by the UE in RRC _ IDLE state and RRC _ INACTIVE state taking PDC into account. The measurement quantities 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 to perform random access according to the measurement result.

The random access preamble (e.g., random access preamble index) and/or time-frequency resources (e.g., subframe number) may be mapped to the measured estimated propagation delay. The estimated propagation delay can be divided into several levels, and the related scheme includes:

1) The estimated propagation delay can be divided into two levels, namely a level where PDC needs to be performed and a level where PDC does not need to be performed. The random access preamble and/or the random access resource are mapped to two different levels of propagation delay. After receiving the random access preamble and/or the resource, the base station may determine whether to perform PDC according to the received preamble and/or resource and a mapping relationship between the preamble and the propagation delay. Then, the base station may perform PDC by itself, or send, to the UE, PDC-related configuration (PDC value and related measurement configuration) corresponding to the propagation delay level, so that the UE performs PDC, related measurement, or/and report of measurement.

2) The estimated propagation delay may be divided into three levels or more. The random access preamble and/or the random access resource are mapped to different levels of propagation delay. The UE or the base station selects a random access preamble and/or a random access resource for the random access procedure corresponding to the estimated propagation delay. The base station may determine a propagation delay level between the UE and the base station based on the received random access preamble and/or resources. The base station may perform PDC itself, or send, to the UE, PDC-related configuration (PDC value and related measurement configuration) corresponding to the propagation delay level, so that the UE may perform PDC, related measurement, or/and reporting of measurement.

3) An algorithm or formula is provided 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 is used for random access procedures between the UE and the base station. After receiving the random access preamble and/or the resource, the base station may determine a level of propagation delay according to the received preamble and/or resource and a corresponding algorithm. The base station may perform PDC by itself, or send, to the UE, PDC-related configuration (PDC value and related measurement configuration) corresponding to the propagation delay level, so that the UE performs PDC, related measurement, or/and report of measurement.

4) A mapping or relationship between the propagation delay and the random access preamble (and/or random access resource) may be established. In particular, this mapping may be a mapping between a level or value of the propagation delay and the random access preamble index (and/or subframe number), for example. Other parameters may also be used to implement this mapping. The base station may determine the level of propagation delay based on the received random access preamble and/or resources and the mapping or relationship. The base station may perform PDC itself, or send, to the UE, PDC-related configuration (PDC value and related measurement configuration) corresponding to the propagation delay level, so that the UE may perform PDC, related measurement, or/and reporting of measurement.

For UE random access, PDC-specific signaling may be defined for the UE to send a PDC request and related information to the base station so that the UE may obtain a PDC configuration from the base station to perform PDC. The PDC request sent by the UE to the base station may contain at least one of location and/or velocity information of the UE, subcarrier Spacing (SCS), synchronization accuracy, and the like.

Mapping rules for UE speed and TA update period (which may be by configuring timeAlignmentTimer) may be defined. That is, the UE reports its speed information to the base station, and the base station determines a TA update period according to the speed information and configures the UE to execute a TA update procedure. Alternatively, the UE is configured with a mapping rule of 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 a TA update procedure by transmitting a TA update request to the base station.

A threshold may be defined for the UE that determines whether to perform PDC based on the status of the UE and/or related measurements. For the threshold value thresh1, which may be configured or standardizable by the base station, the UE performs the PDC procedure if the measurement result (e.g., RARP/RSRQ/SINR) meas _ r < (or < =) thresh1, or if TA (or the distance between the UE and the base station) Tta > (or > =) thresh 1. Conversely, it can be defined that if the measurement result (e.g., RARP/RSRQ/SINR) meas _ r > (or > =) thresh1, the UE stops executing the PDC procedure, or if TA (or the distance between the UE and the base station) Tta < (or < =) thresh1, the UE stops executing the PDC procedure. Another way is that another threshold value thresh2 may be defined, where thresh2< thresh1, the UE executes PDC if meas _ r < (or < =) thresh2, and stops executing PDC if meas _ r > = (or >) thresh 1; similarly, if Tta > (or > =) thresh1, the UE executes the PDC procedure, and if Tta < (or < =) thresh2, the UE stops executing the PDC.

When an event meas _ r < (or < =) thresh1 (Tta > (or > =) thresh1, etc.) occurs, the UE may send a PDC request to the base station, and then the base station may send signaling to instruct the UE to start or stop performing PDC using the value obtained from the base station.

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, when configured by the base station or triggered by a related event.

A default value may be defined for PDC, which the UE uses to perform PDC before receiving the PDC configuration from the base station. Also, the PDC may be TA based, e.g., T _PDC ＝delta*T _TA Or/and T _{PDC_new} ＝T _{PDC_old} + alph, delta may be a constant (e.g., 1/2) or may be configurable, and alph may be obtained from the base station.

Fig. 3 is a flowchart illustrating a method for performing measurement, cell (re) selection, and propagation delay compensation when performing random access for a UE in an RRC _ IDLE state or an RRC _ INACTIVE state according to a first embodiment of the present application. Assume 1) the UE is in RRC _ IDLE state or RRC _ INACTIVE state; and 2) the UE performs measurement and cell (re) selection.

Referring to fig. 3, in step 0, the UE in the RRC _ IDLE state or the RRC _ INACTIVE state performs measurement and cell (re) selection. A measurement quantity tsn _ delay is defined (for a UE in RRC _ IDLE state and/or RRC _ INACTIVE state) to estimate the propagation delay between the UE and the base station (or from UE to base station, or from base station to UE) using, for example, reference Signal Received Power (RSRP). The measurement tsn _ delay may be applicable for 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 a cell with the largest or smallest tsn _ delay value as a candidate cell to perform random access and connect to the candidate cell. The measurement tsn _ delay may be mapped to a time Advance (Timing Advance) or distance between the UE and the base station, or any other quantity that may identify a propagation delay between the UE and the base station.

In step 1, the UE sends the selected random access preamble to the candidate base station. In one embodiment, a UE supporting time sensitive traffic (e.g., TSN traffic) (pre-configured and/or standardizable, etc.) may be assigned a subset of random access preambles for random access, with the UE selecting one of the preambles and transmitting it to the base station. In another embodiment, a UE supporting time sensitive traffic (e.g., TSN traffic) (pre-configured and/or standardizable, etc.) may be allocated a subset of time-frequency resources for random access, with the UE transmitting a random access preamble on the resources in the subset.

In step 2, the base station receives a Random Access preamble from the UE and transmits a Random Access Response (RAR) message to the UE. In one embodiment, a base station receives a dedicated time-sensitive random access preamble from a UE and sends a PDC configuration message, including a propagation delay between the UE and the base station, included in a RAR message to the UE. In another embodiment, the base station receives a random access preamble transmitted using a dedicated time-sensitive time-frequency resource and transmits a PDC configuration message including a propagation delay between the UE and the base station to the UE, which is included in the RAR message. The UE may perform propagation delay compensation immediately or in a subsequent step after receiving the PDC configuration message to compensate for propagation delay between the UE and the base station.

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

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

In step 5, the UE performs the PDC procedure.

In one embodiment, the PDC configuration message sent by the base station may include an information element for the UE to perform PDC using a Timing Advance Command (TAC).

In another embodiment, the PDC configuration message sent by the base station may contain a single bit or a field comprising multiple bits for the UE to start or stop PDC.

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

a) One threshold thresh1 for UE to start or stop PDC, e.g. if T _TA >(=) thresh1, UE starts PDC, or/and if T _TA <(=) thresh1, UE stops PDC;

b) Two thresholds thresh1 and thresh2, where thresh1>thresh2 for the UE to start or stop PDC. For example, if T _TA >(=) thresh1, the UE starts PDC, if T _TA <(=) thresh2, the UE stops PDC;

c) UE sends PDC request or updates PDC value or adjusts the period of relative timer;

d) Period to speed mapping rules, etc.

Example 2

A UE in RRC _ CONNECTED state may perform measurements and reporting of base station (e.g., gNB) configuration, as well as time advanced update procedures. For the moving UE, the period for the UE to send the measurement report may be configured according to the moving speed, and the faster the UE moves, the shorter the period for the measurement report. Similarly, the faster the UE moves, the shorter the period of TA update. A mapping relationship between the moving speed and the period for the UE to perform measurement reporting may be defined for the UE. The relationship between the moving speed of the UE and the TA update period may be of the same design.

The configuration of the measurement report and the configuration of the TA update may take into account the location of the UE or the distance between the UE and the base station. The farther the UE is from the base station, the shorter the period of measurement reporting. Such a design is also applicable to the configuration of TA updates.

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

The location information and/or velocity information may be transmitted to the base station and may be included in a measurement report, PDC request message, or the like.

As described in embodiment 1, a threshold may be defined for the UE to start or stop PDC.

Fig. 4 shows a flowchart of a method for performing measurement and reporting delay compensation for a UE in an RRC _ CONNECTED state according to a second embodiment of the present application. Assume 1) both the UE and the base station support time sensitive traffic; and 2) the UE is in RRC _ CONNECTED state and CONNECTED with the serving base station.

Referring to fig. 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. The UE then performs measurements to generate a measurement report, as shown in step 1 a. Measurements 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/position/velocity/distance, etc. For example, RSRP/RSRQ/SINR/position/TA/distance may be used.

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

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

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

In step 4, the UE receives the PDC request acknowledgement and performs propagation delay compensation, updating the time synchronization. The UE performs PDC using the latest configuration received from the base station.

Example 3

This embodiment focuses on Propagation Delay Compensation (PDC) during handover (handover). Fig. 5 shows a flowchart of a method for propagation delay compensation during handover according to a third embodiment of the present application. As shown in fig. 5, the PDC REQUEST message may be sent by the source base station to the target base station in a HANDOVER command (e.g., HANDOVER REQUEST message), and a PDC REQUEST acknowledgement from the target base station may be sent by the source base station to the UE. In addition, a PDC request message or PDC related measurement report may be sent to the target base station in message 3, included in the handover procedure initiated random access procedure, and a PDC configuration/request acknowledgement message may be sent to the UE in message 4. The base station may learn about PDC requirements by receiving a random access preamble transmitted using a dedicated resource or preamble index, and obtain TSCAI from a source base station or Core Network (CN) or Network (NW) (e.g., 5 GC), and then send PDC configurations to the UE.

UE handover is performed between a source base station (e.g., source gNB) and a target base station (e.g., target gNB). Hereinafter, assume 1) that UE, source base station and target base station all support time-sensitive services; 2) The UE is in an RRC _ CONNECTED state and is CONNECTED with a source base station; 3) UE is measuring and reporting; and 4) the UE is performing a handover procedure.

Referring to fig. 5, the ue transmits a PDC request message to the target base station. In one embodiment, the UE sends a PDC request to the source base station, and the source base station forwards the PDC request message to the target base station, as shown in step 1 a. In another embodiment, the UE transmits a random access preamble dedicated for time-sensitive traffic to the target base station or/and transmits the random access preamble with dedicated random access time-frequency resources indicated by the source base station, as shown in step 1b. In yet another embodiment, the UE sends the PDC request in message 3 to the target base station.

The target base station receives the PDC request from the UE and sends the 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 the random access preamble with the preamble and/or the random access time-frequency resource 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 the PDC request from the UE in message 3.

The target base station generates a PDC configuration and sends it to the UE either through the source base station (step 2 a) or directly (step 2 b). The target base station may 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 along with a contention resolution message (i.e., message 4).

The UE continues the remaining steps of the handover procedure and performs PDC related measurements and PDC procedures.

As shown in fig. 6, the handover procedure mentioned in the present application includes at least a handover preparation phase, a handover execution phase, and a handover completion phase.

In the handover preparation phase, the UE performs measurement and reporting according to the configuration of measurement and reporting received from the base station or according to the relevant 3GPP standard specification. When the switching condition is met, the source base station sends a switching request to a selected or candidate target base station. If the candidate target base station accepts the handover request, the target base station transmits a handover request acknowledgement (acknowledgement) to the source base station. Then, RAN handover is started.

The UE performs a handover procedure initiated random access procedure (e.g., contention-free random access or contention-based random access) during a handover execution phase according to a configuration from the source base station, e.g., rcconnectionreconfiguration. The remaining data from the core network will be forwarded by the source base station to the target base station before the path switch is completed.

Then, the path switching is performed at the switching completion stage. A path switch request is issued from the target base station to the core network and once acknowledged (acknowledged), data may flow from the UE through the target base station to release the UE context.

Fig. 7 shows a block diagram of an example system 700 for wireless communication in accordance with an embodiment of the present application. The embodiments described herein may be implemented into the system using any suitably configured hardware and/or software. Fig. 7 shows a system 700, the system 700 including Radio Frequency (RF) circuitry 710, baseband circuitry 720, processing unit 730, memory/storage 740, display 750, camera 760, sensor 770, and input/output (I/O) interface 780, coupled to each other as shown.

Processing unit 730 may include circuitry, 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 with the memory/storage and configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems to run on the system.

Baseband circuitry 720 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor may comprise a baseband processor. The baseband circuitry may handle various wireless control functions that enable communication with one or more radio networks via the RF circuitry. The radio control functions may include, but are not limited to, signal modulation, encoding, decoding, radio frequency shifting, and the like. In some embodiments, the baseband circuitry may provide communications compatible with one or more wireless technologies. For example, in some embodiments, the baseband circuitry may support communication with 5G NR, LTE, evolved Universal Terrestrial Radio Access Network (EUTRAN), and/or other wireless wide area networks (WMANs), wireless Local Area Networks (WLANs), wireless Personal Area Networks (WPANs). Embodiments in which the baseband circuitry is configured to support wireless communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry. In various embodiments, baseband circuitry 720 may include circuitry for operating with signals that are not strictly considered to be in baseband frequencies. For example, in some embodiments, the baseband circuitry may include circuitry for operating with signals having an intermediate frequency between the baseband frequency and the radio frequency.

RF circuitry 710 may use the modulated electromagnetic radiation to enable communication with a wireless network through a non-solid medium. In various embodiments, the RF circuitry may include switches, filters, amplifiers, and the like to facilitate communication with the wireless network. In various embodiments, RF circuitry 710 may include circuitry for operating with signals that are not strictly considered to be at radio frequencies. For example, in some embodiments, the RF circuitry may include circuitry for operating with signals having an intermediate frequency between a baseband frequency and a radio frequency.

In various embodiments, the transmitter circuitry, control circuitry, or receiver circuitry discussed above with respect to the user equipment, eNB, or gNB may be implemented in whole or in part in one or more of the RF circuitry, baseband circuitry, and/or processing units. As used herein, "circuitry" may refer to, may be part of, or include the following: an Application Specific Integrated Circuit (ASIC), an electronic circuit executing one or more software or firmware programs, a processor and/or memory (shared, dedicated, or group) combined logic and/or other suitable hardware components to provide the described functionality. In some embodiments, the electronics circuitry may be implemented in, or functions associated with, one or more software or firmware modules. In some embodiments, some or all of the constituent components of the baseband circuitry, processing unit, and/or memory/storage devices may be implemented together on a system-on-a-chip (SOC).

Memory/storage 740 may be used to load and store data and/or instructions, for example, for a system. The memory/storage of one 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 designed to enable a user to interact with the system and/or a peripheral component interface 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 touchpad, a speaker, a microphone, and the like. The peripheral component interfaces may include, but are not limited to, a non-volatile memory interface, a Universal Serial Bus (USB) interface, an audio jack, and a power interface.

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 sensors may include, but are 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 baseband circuitry and/or RF circuitry to communicate with components of a positioning network, such as Global Positioning System (GPS) satellites. In various embodiments, display 750 may include displays such as liquid crystal displays and touch screen displays. In various embodiments, 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 smartphone, and the like. In various embodiments, the system may have more or fewer components and/or different architectures. Where appropriate, the methods 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.

Some embodiments of the present application are a combination of "technologies/processes" that may be employed in 3GPP specifications to develop an end product.

It will be understood by those skilled in the art that each of the units, algorithms, and steps 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 performed in hardware or software depends on the application conditions and the design requirements of the solution. Skilled artisans may implement the functionality in varying ways for each particular application, and such implementation decisions should not be interpreted as causing a departure from the scope of the present application. It will be appreciated by those skilled in the art that reference may be made to the operation of the systems, devices and units described in the above embodiments as the operation of the systems, devices and units described above is substantially the same. For convenience of description and brevity, these operations will not be described in detail.

It should be understood that the system, apparatus and method disclosed in the embodiments of the present application may be implemented in other ways. The embodiments described above are merely illustrative. The partitioning of cells is based only on logical functions, while other partitions exist when implemented. Multiple units or components may be combined or may be integrated into another system. Some features may also be omitted or skipped. On the other hand, the mutual coupling, direct coupling or communication coupling shown or discussed may be an indirect coupling or an electrical, mechanical or other form of communication coupling through some interfaces, devices or units.

The elements described as separate components may or may not be physically separate. The displayed elements may or may not be physical elements, i.e. may be located in one place or may be distributed over a plurality of network elements. Some or all of the units may be used according to the purpose of the embodiments. In addition, functional units in the embodiments may be integrated into one processing unit, may be physically independent, or may be integrated into one processing unit by two or more units.

If the software functional units are implemented and sold or used as a stand-alone product, they may be stored in a computer readable storage medium. Based on such understanding, the technical solutions proposed in the present application can be implemented essentially or partially in the form of software products. Alternatively, a part of the technical solution that is advantageous to the prior art may be implemented in the form of a software product. The software product in the computer is stored in a storage medium and includes a plurality of commands for a computing device (e.g., a personal computer, a server, or a network device) to execute all or part of the steps disclosed in the embodiments of the present application. The storage medium includes a USB disk, a portable hard drive, a read-only memory (ROM), a Random Access Memory (RAM), a floppy disk, or other medium capable of storing program code.

While the application has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the application is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various arrangements made without departing from the scope of the broadest interpretation of the appended claims.

Claims

1. 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.

2. The method of claim 1, wherein prior to the transmitting step, the method further comprises:

the propagation delay is estimated or measured.

3. The method of claim 1, wherein prior to the transmitting step, the method further comprises:

receiving a broadcasted message; and

a propagation delay is estimated from the broadcast message.

4. The method of claim 1, wherein the transmitting step and the receiving step are performed in a random access procedure.

5. The method of claim 4, wherein the transmitting and receiving steps are performed in at least one of an RRC IDLE state and an RRC INACTIVE state.

6. The method of claim 1, wherein, in the transmitting step, the request is transmitted with a random access preamble dedicated to time sensitive traffic.

7. The method of claim 6, wherein prior to the transmitting step, the method further comprises:

the random access preamble is selected from a plurality of subsets of random access preambles mapped to different propagation delays.

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

9. The method of claim 1, wherein, in the transmitting step, the request is transmitted with a random access preamble selected from two sets of random access preambles corresponding to two propagation delay levels, one set of random access preambles indicating that PDC is required and the other set of random access preambles indicating that PDC is not required.

10. The method of claim 1, wherein, in the transmitting step, the request is transmitted with a random access preamble selected from a plurality of sets of random access preambles corresponding to different propagation delay levels.

11. The method of claim 1, wherein, in the transmitting step, the request is transmitted with a random access preamble calculated with an algorithm or formula based on a level or value of a propagation delay.

12. The method of claim 1, wherein in the transmitting step, the request is transmitted with a random access preamble selected according to a mapping or relationship between a propagation delay and the random access preamble.

13. The method of claim 12, wherein the mapping is a mapping between a 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 of claim 1, wherein, in the transmitting step, the request is transmitted in time-frequency resources dedicated to time-sensitive traffic.

16. The method of claim 15, wherein prior to the transmitting step, the method further comprises:

selecting the time frequency resources from a plurality of subsets of time frequency resources mapped to different propagation delays.

17. The method of claim 16, wherein the time-frequency resources are selected based on estimated propagation delays.

18. The method of claim 1, wherein, in the transmitting step, the request is transmitted on a time-frequency resource selected from two sets of time-frequency resources corresponding to two propagation delay levels, one set of time-frequency resources indicating PDC need to be performed and the other set of time-frequency resources indicating PDC not need to be performed.

19. The method of claim 1, wherein, in the transmitting step, the request is transmitted on a time-frequency resource selected from a plurality of sets of time-frequency resources corresponding to different propagation delay levels.

20. The method of claim 1, wherein, in the transmitting step, the request is transmitted in time-frequency resources calculated by an algorithm or formula based on a level or value of a propagation delay.

21. The method according to claim 1, wherein in the transmitting step the request is transmitted in a time-frequency resource selected according to a mapping or relation between propagation delay and time-frequency resource.

22. The method of claim 21, wherein the mapping is a mapping between a level or value of the propagation delay and a subframe number.

23. The method according to claim 1, wherein in the receiving step, the PDC configuration is received through a Random Access Response (RAR).

24. The method of claim 1, wherein in the transmitting step, the request is transmitted in a random access procedure with message 3.

25. The method of claim 1, wherein, in the receiving step, the PDC configuration is received with a contention resolution message.

26. The method of claim 1, wherein the PDC configuration includes an information element to perform the PDC using a Time Advance Command (TAC).

27. The method of claim 1, wherein the PDC configuration contains one bit or a field comprising several bits to start or stop executing the PDC.

28. The method of claim 1, wherein said PDC configuration includes a threshold for deciding to start or stop executing said PDC.

29. The method of claim 1, wherein the PDC configuration includes two thresholds for deciding to start or stop executing the PDC, and wherein the two thresholds have different values.

30. The method of claim 1, wherein the PDC configuration includes at least one of a period to request the PDC, a period to execute the PDC, and a period to update a Time Advance (TA).

31. The method of claim 30, wherein the PDC configuration includes a mapping rule between the period and a movement speed.

32. The method of claim 1, wherein the transmitting and receiving steps are performed in an RRC _ CONNECTED state.

33. The method of claim 1, further comprising:

receiving measurement and reporting configuration;

estimating or measuring the propagation delay and generating a measurement report based on the measurement and reporting configuration; and

and sending the measurement report.

34. The method of claim 1, further comprising:

and carrying out measurement and report related to the PDC according to the PDC configuration.

35. The method of claim 1, further comprising:

performing a time-ahead (TA) update procedure according to the PDC configuration.

36. The method of claim 1, further comprising:

performing measurements related to the PDC to generate a measurement report; and

the measurement report is sent out and sent out,

wherein a period of sending the measurement report depends on at least one of a movement speed and location information.

37. The method of claim 1, wherein a period of sending the request depends on at least one of a movement speed and location information.

38. The method of claim 1, further comprising:

the update Time Advance (TA) is,

wherein a period of updating the TA depends on at least one of a movement speed and location information.

39. The method according to claim 1, wherein in said receiving step, said PDC configuration is received together with a request acknowledgement.

40. The method of claim 1, wherein the receiving and transmitting steps are performed during a handover procedure.

41. The method of claim 1, wherein in the transmitting step, the request is transmitted in a handover command.

42. The method of claim 41, wherein, in the receiving step, the PDC configuration is received with an acknowledgement of the handover command.

43. The method of claim 1, wherein in the transmitting step, the request is transmitted with a random access preamble dedicated to time sensitive traffic in a random access procedure initiated by a handover procedure.

44. The method according to 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 procedure.

45. The method of claim 1, wherein in the sending step, the request is sent in message 3 in a random access procedure initiated by a handover procedure, the message 3 is sent to a target device, and random access is performed for handover to the target device.

46. The method of claim 1, wherein in the transmitting step, the PDC configuration is received through a message 4 in a random access procedure initiated by a handover procedure, the message 4 being transmitted from a target device, performing random access for handover to the target device.

47. The method of claim 1, further comprising:

PDC related measurements are sent in a random access procedure initiated by a handover procedure.

48. A Propagation Delay Compensation (PDC) method, comprising:

receiving a request for propagation delay compensation; and

the PDC configuration to compensate for propagation delay is sent.

49. The method of claim 48, further comprising:

a message for propagation delay estimation is broadcast.

50. The method of claim 48, wherein the transmitting and receiving steps are performed in a random access procedure.

51. The method of claim 48, wherein in the receiving step, a random access preamble dedicated to time sensitive traffic is received to receive the request.

52. The method of claim 51, wherein the random access preamble is from a plurality of subsets of random access preambles mapped to different propagation delays.

53. The method of claim 52, wherein the random access preamble is based on an estimated propagation delay.

54. The method of claim 48, wherein in the receiving step, time-frequency resources dedicated to time sensitive traffic are received to receive the request.

55. The method of claim 54, wherein the time-frequency resources are from a plurality of subsets of time-frequency resources mapped to different propagation delays.

56. The method of claim 55, wherein the time-frequency resources are based on estimated propagation delays.

57. The method of claim 48, wherein in the receiving step, the PDC configuration corresponds to a level or value of a propagation delay.

58. The method according to claim 48, wherein in the sending step, the PDC configuration is sent in a Random Access Response (RAR).

59. The method of claim 48, wherein, in the receiving step, the request is received via message 3 in a random access procedure.

60. The method of claim 48, wherein, in the transmitting step, the PDC configuration is transmitted via a contention resolution message.

61. The method of claim 48, wherein said PDC configuration includes an information element to enable said PDC using a Time Advance Command (TAC).

62. The method of claim 48, wherein said PDC configuration contains one bit or a field comprising several bits to start or stop executing said PDC.

63. The method of claim 48, wherein said PDC configuration includes a threshold for deciding to start or stop executing said PDC.

64. The method of claim 48, wherein said PDC configuration includes two thresholds used to decide to start or stop execution of said PDC, and wherein said two thresholds have different values.

65. The method of claim 48, wherein the PDC configuration includes at least one of a period during which the PDC is requested, a period during which the PDC is executed, and a period during which an update Time Advance (TA) is updated.

66. The method of claim 65, wherein the PDC configuration includes a mapping rule between the periodicity and a movement speed.

67. The method of claim 48, wherein the receiving and transmitting steps are performed in an RRC _ CONNECTED state.

68. The method of claim 48, further comprising:

sending measurement and reporting configuration; and

and receiving a measurement report generated according to the measurement and report configuration.

69. The method of claim 48, further comprising:

a measurement report related to the PDC is received,

wherein a period of receiving the PDC related measurement report is dependent on at least one of movement speed and location information.

70. The method of claim 48, wherein a period of receiving the request is dependent on at least one of a speed of movement and location information.

71. The method of claim 48, further comprising:

a Time Advance (TA) is provided,

wherein a period for providing the TA depends on at least one of a moving speed and location information.

72. The method of claim 48, wherein, in said transmitting step, said PDC is configured to request an acknowledgement for transmission.

73. A method of cell (re) selection, comprising:

estimating or measuring a propagation delay between the UE and the base station to generate a measurement comprising a propagation delay value relative to the measured base station;

selecting a candidate base station from the measured base stations according to the propagation delay value; and

connecting to the candidate base station.

74. The method of claim 73, wherein prior to the estimating or measuring step, the method further comprises:

a broadcast message transmitted using dedicated time-frequency resources is received.

75. The method of claim 74, wherein in the estimating or measuring step, the propagation delay is obtained from the broadcast message.

76. The method of claim 73, wherein the UE is in one of an RRC _ IDLE state and an RRC _ INACTIVE state.

77. The method of claim 73, wherein the propagation delay value maps to a time advance between the UE and the base station.

78. The method of claim 73, wherein the propagation delay value maps to a distance between the UE and the base station.

79. A User Equipment (UE), comprising:

a processor configured to invoke and execute program instructions stored in the memory to perform the method of any of claims 1 to 47.

80. A base station, comprising:

a processor configured to invoke and execute program instructions stored in memory to perform the method of any of claims 48 to 72.

81. A User Equipment (UE), comprising:

a processor configured to invoke and execute program instructions stored in memory to perform the method of any of claims 73 to 78.