CN111698735A

CN111698735A - Communication method and communication device in wireless communication technical field

Info

Publication number: CN111698735A
Application number: CN201910182807.4A
Authority: CN
Inventors: 张宏平
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-03-12
Filing date: 2019-03-12
Publication date: 2020-09-22
Also published as: WO2020182031A1

Abstract

The application provides a communication method and a communication device, wherein the method comprises the following steps: receiving first information from a source base station, wherein the first information comprises one or more of measurement result information of a downlink between a first terminal and a target base station and position information of the first terminal, and the first information is used for determining a first timing advance, and the first timing advance is timing advance of uplink transmission between the first terminal and the target base station; and sending the information of the first timing advance to the first terminal through the source base station. The method and the device can determine the timing advance through the target base station and send the timing advance to the terminal equipment, so that the terminal equipment can skip a random access program in the process of switching the base station, signaling overhead and data transmission time delay are reduced, and the use experience of a user is improved.

Description

Communication method and communication device in wireless communication technical field

Technical Field

The present application relates to the field of wireless communication technologies, and in particular, to a communication method and a communication apparatus.

Background

In the existing communication network, along with the movement of the terminal device, when the terminal device using the network service moves from the coverage of one cell to the coverage of another cell or due to reasons such as adjustment of wireless transmission traffic load, in order to ensure the continuity of communication and the quality of service, the system needs to transfer the communication link between the terminal device and the original cell to a new cell, and this process is Handover (Handover). For example, in the handover process, a step of random access is included, and the random access mainly functions to determine a Timing Advance (TA) amount and an Initial Transmission Power (ITP) of communication between the terminal device and a target cell under a target base station, and in the step, a delay of at least several tens of milliseconds is caused.

With the development of communication technology, the requirement for delay in a communication protocol is higher and higher, and therefore how to reduce delay in the handover process of a terminal device becomes an urgent problem to be solved.

Disclosure of Invention

The application provides a communication method and a communication device. The timing advance can be obtained from the target base station in the switching process, so that the random access procedure can be skipped, and the time delay is reduced.

In a first aspect, a communication method is provided, which may be performed by a network device, or may also be performed by a chip or a circuit configured in the network device, and the network device may be a target base station, which is not limited in this application.

For example, the network device may be a base station, such as an eNB, a gNB, a CU, or a DU, without limitation.

Specifically, the method comprises the following steps: receiving first information from a source base station, wherein the first information comprises one or more of measurement result information of a downlink between a first terminal and a target base station and position information of the first terminal, and the first information is used for determining a first timing advance which is a timing advance of uplink transmission between the first terminal and the target base station; and sending the information of the first timing advance to the first terminal through the source base station.

The communication method provided by the embodiment of the application can determine the timing advance according to the first information, so that a random access program can be skipped in the process of switching the base station, the signaling overhead and the time delay of data transmission are reduced, and the use experience of a user is improved.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: determining the distance between the first terminal and the target base station according to the first information; and determining a first timing advance according to the distance between the first terminal and the target base station.

With reference to the first aspect, in some implementations of the first aspect, when the first information includes measurement result information, determining a distance between the terminal device and the target base station according to the first information includes: determining the path loss between the target base station and the first terminal according to the measurement result information; and determining the distance between the first terminal and the target base station according to the path loss.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: acquiring a mapping relation, wherein the mapping relation is a mapping relation between second information and a second timing advance, the second information comprises one or more of measurement result information of a downlink between a second terminal and the target base station and position information of the second terminal, and the second timing advance is a timing advance of uplink transmission between the second terminal and the target base station;

and determining a first timing advance according to the mapping relation and the first information.

With reference to the first aspect, in certain implementations of the first aspect, the measurement result information includes information of received power of the reference signal.

With reference to the first aspect, in some implementation manners of the first aspect, the first information is carried in a handover request message, and the information of the first timing advance is carried in a handover confirmation message and a handover command message.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: receiving an RRC reconfiguration complete message from the first terminal, the RRC reconfiguration complete message transmitted based on the first timing advance.

With reference to the first aspect, in some implementations of the first aspect, the first information is further used to determine an initial transmit power of an uplink transmission between the first terminal and the target base station; the method further comprises the following steps: and sending the information of the initial transmitting power to the first terminal through the source base station.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: determining path loss between the first terminal and the target base station according to the first information; the initial transmit power is determined from the path loss.

With reference to the first aspect, in some implementations of the first aspect, when the first information includes location information of the first terminal, determining a path loss between the first terminal and the target base station according to the first information includes: determining the distance between the first terminal and the target base station according to the position information of the first terminal; and determining the path loss between the first terminal and the target base station according to the distance between the first terminal and the target base station.

With reference to the first aspect, in some implementations of the first aspect, an RRC reconfiguration complete message is received from the first terminal, the RRC reconfiguration complete message being transmitted based on the initial transmit power.

In a second aspect, a communication method is provided, which may be executed by a terminal device, or may also be executed by a chip or a circuit configured in the terminal device, and this application is not limited thereto.

Specifically, the method comprises the following steps: receiving a timing advance of uplink transmission between a first terminal and a target base station from the target base station through a source base station; wherein the timing advance is determined according to first information, and the first information comprises one or more of measurement result information of a downlink between the first terminal and the target base station and position information of the first terminal.

With reference to the second aspect, in certain implementations of the second aspect, the measurement result information includes information of received power of the reference signal.

With reference to the second aspect, in some implementations of the second aspect, the information of the timing advance is carried in a handover confirm message and a handover command message.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: and sending an RRC reconfiguration complete message to the target base station, wherein the RRC reconfiguration complete message is transmitted based on the timing advance.

With reference to the second aspect, in some implementations of the second aspect, if the RRC reconfiguration complete message transmission fails, the method further includes: and initiating random access to the target base station.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: and receiving information of initial transmitting power of uplink transmission between the first terminal and the target base station from the target base station through the source base station, wherein the initial transmitting power is determined according to the first information.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: sending an RRC reconfiguration complete message to the target base station, the RRC reconfiguration complete message being transmitted based on the initial transmit power.

In a third aspect, a communication method is provided, which may be performed by a network device, or may also be performed by a chip or a circuit configured in the network device, and the network device may be a source base station, which is not limited in this application.

Specifically, the method comprises the following steps: sending first information to a target base station, wherein the first information is used for determining the timing advance of uplink transmission between a first terminal and the target base station, and the first information comprises one or more of measurement result information of a downlink between the first terminal and the target base station and position information of the first terminal; receiving timing advance information from a target base station; and sending the information of the timing advance to the first terminal.

With reference to the third aspect, in certain implementations of the third aspect, the measurement result information includes information of received power of the reference signal.

With reference to the third aspect, in some implementations of the third aspect, the first information is carried in a handover request message, and the information of the timing advance is carried in a handover confirmation message and a handover command message.

With reference to the third aspect, in certain implementations of the third aspect, the method further includes: receiving information of initial transmitting power of uplink transmission between a first terminal and a target base station from the target base station, wherein the initial transmitting power is determined according to the first information; and sending the information of the initial transmission power to the first terminal.

In a fourth aspect, a communication method is provided, which may be executed by a network device, or may also be executed by a chip or a circuit configured in the network device, and the network device may be a target base station, which is not limited in this application.

Specifically, the method comprises the following steps: and sending first indication information to the first terminal through the source base station, wherein the first indication information is used for indicating the first terminal to determine the timing advance of uplink transmission between the first terminal and the target base station.

With reference to the fourth aspect, in some implementations of the fourth aspect, the first indication information includes location information of the target base station.

With reference to the fourth aspect, in some implementations of the fourth aspect, the first indication information is carried in a handover confirm message and a handover command message.

With reference to the fourth aspect, in some implementations of the fourth aspect, an RRC reconfiguration complete message is received from the first terminal, the RRC reconfiguration complete message being transmitted based on the timing advance.

With reference to the fourth aspect, in some implementations of the fourth aspect, the first indication information is used to instruct the first terminal to determine an initial transmission power of uplink transmission between the first terminal and the target base station.

With reference to the fourth aspect, in some implementations of the fourth aspect, an RRC reconfiguration complete message is received from the first terminal, the RRC reconfiguration complete message being based on the initial transmit power transmission.

In a fifth aspect, a communication method is provided, which may be executed by a terminal device, or may also be executed by a chip or a circuit configured in the terminal device, and this application is not limited thereto.

Specifically, the method comprises the following steps: receiving first indication information from a target base station through a source base station, wherein the first indication information is used for indicating a first terminal to determine a timing advance of uplink transmission between the first terminal and the target base station; the timing advance is determined.

With reference to the fifth aspect, in certain implementations of the fifth aspect, determining the timing advance comprises: determining the distance between a first terminal and a target base station; and determining the timing advance according to the distance between the first terminal and the target base station.

With reference to the fifth aspect, in some implementations of the fifth aspect, determining the distance between the first terminal and the target base station includes: determining the path loss between the target base station and the first terminal according to the measurement result information of the downlink between the first terminal and the target base station; and determining the distance between the first terminal and the target base station according to the path loss.

With reference to the fifth aspect, in some implementations of the fifth aspect, the first indication information further includes location information of the target base station, and determining the distance between the first terminal and the target base station includes: and determining the distance between the first terminal and the target base station according to the position information of the target base station.

With reference to the fifth aspect, in certain implementations of the fifth aspect, determining the timing advance comprises: acquiring a mapping relation, wherein the mapping relation is a mapping relation between second information and a second timing advance, the second information comprises one or more of measurement result information of a downlink between a second terminal and a target base station and position information of the second terminal, and the second timing advance is a timing advance of uplink transmission between the second terminal and the target base station;

and determining the timing advance according to the mapping relation and the first information.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the measurement result information includes information of received power of the reference signal.

With reference to the fifth aspect, in some implementations of the fifth aspect, the first indication information is carried in a handover confirm message and a handover command message.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the method further comprises: and sending an RRC reconfiguration complete message to the target base station, wherein the RRC reconfiguration complete message is transmitted based on the first timing advance.

With reference to the fifth aspect, in some implementations of the fifth aspect, the first indication information is further used to instruct the first terminal to determine an initial transmission power of uplink transmission between the first terminal and the target base station; the method further comprises the following steps: and determining the initial transmitting power of uplink transmission between the first terminal and the target base station.

With reference to the fifth aspect, in some implementations of the fifth aspect, determining an initial transmit power of an uplink transmission between the first terminal and the target base station includes: determining path loss between the first terminal and the target base station according to the measurement result information of the downlink between the first terminal and the target base station; the initial transmit power is determined from the path loss.

With reference to the fifth aspect, in some implementations of the fifth aspect, when the first information includes location information of the target base station, determining a path loss between the first terminal and the target base station includes: determining the distance between a first terminal and a target base station according to the position information of the target base station; and determining the path loss between the first terminal and the target base station according to the distance between the first terminal and the target base station.

With reference to the fifth aspect, in some implementations of the fifth aspect, an RRC reconfiguration complete message is sent to the target base station, the RRC reconfiguration complete message being based on the initial transmission power transmission.

In a sixth aspect, a communication method is provided, which may be performed by a network device, or may also be performed by a chip or a circuit configured in the network device, and the network device may be a source base station, which is not limited in this application.

Specifically, the method comprises the following steps: receiving first indication information sent by a target base station, wherein the first indication information is used for indicating a first terminal to determine a timing advance of uplink transmission between the first terminal and the target base station; and sending the first indication information to the first terminal.

With reference to the sixth aspect, in some implementations of the sixth aspect, the first indication information includes location information of the target base station.

With reference to the sixth aspect, in some implementations of the sixth aspect, the first indication information is used to instruct the first terminal to determine an initial transmission power of uplink transmission between the first terminal and the target base station.

With reference to the sixth aspect, in some implementations of the sixth aspect, the first indication information is carried in a handover confirm message and a handover command message.

In a seventh aspect, there is provided a communication device comprising a processor coupled with a memory, the memory being configured to store a computer program or instructions, the processor being configured to execute the computer program or instructions such that the method of any of the first to sixth aspects is performed, the communication device further comprising the memory.

In an eighth aspect, there is provided a communication device comprising one or more modules for implementing the method of any of the above first to sixth aspects, which may correspond to the steps of the method of any of the above first to sixth aspects.

In a ninth aspect, there is provided a chip comprising a processor and interface circuitry, the interface circuitry being coupled to the processor, the processor being configured to execute a computer program or instructions to implement a method as in any of the first to sixth aspects, the interface circuitry being configured to communicate with modules external to the chip.

A tenth aspect provides a computer storage medium storing a program for implementing the method of any one of the first to sixth aspects. The program, when run in a wireless communication device, causes the wireless communication device to perform the method of any of the first to sixth aspects.

In an eleventh aspect, the present application provides a computer program product, which includes a program that, when executed, causes the method of any one of the first to sixth aspects to be performed.

According to the embodiment of the application, the first timing advance and the first initial transmitting power can be determined through the target base station, the related information is sent to the terminal equipment, the terminal equipment can skip a random access program (the time consumption of the random access program is about dozens of milliseconds), the related parameters are directly used for establishing connection with the target base station, and uplink data transmission is carried out, so that the signaling overhead is reduced, the time delay is reduced, and the user experience is improved.

Drawings

Fig. 1 is a schematic diagram of a communication system suitable for use with the method provided by an embodiment of the present application;

fig. 2 is a schematic flowchart of an example of a communication method of the present application;

fig. 3 is a schematic flowchart of another example of the communication method of the present application;

fig. 4 is a schematic flow chart of still another example of the communication method of the present application;

fig. 5 is a schematic flow chart of still another example of the communication method of the present application;

fig. 6 is a schematic flowchart of still another example of the communication method of the present application;

fig. 7 is a schematic flowchart of still another example of the communication method of the present application;

fig. 8 is a schematic structural diagram of a network device according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of a terminal device provided in an embodiment of the present application;

fig. 10 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

fig. 11 is a schematic block diagram of a network device provided in an embodiment of the present application;

fig. 12 is a schematic block diagram of a terminal device provided in an embodiment of the present application;

fig. 13 is a schematic block diagram of a network device according to an embodiment of the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

The technical scheme of the embodiment of the application can be applied to various communication systems, for example: a Long Term Evolution (LTE) system, an LTE Frequency Division Duplex (FDD) system, an LTE Time Division Duplex (TDD) system, a Universal Mobile Telecommunications System (UMTS), a fifth generation (5G) system, a New Radio (NR) or other evolved communication systems, and the like.

The terminal device in the embodiment of the present application may also be referred to as: a terminal, User Equipment (UE), Mobile Station (MS), Mobile Terminal (MT), access terminal, subscriber unit, subscriber station, mobile station, remote terminal, mobile device, user terminal, wireless communication device, user agent, or user device, etc.

The terminal device may be a device providing voice/data connectivity to a user, e.g. a handheld device, a vehicle mounted device, etc. with wireless connection capability. Currently, some examples of terminals are: a mobile phone (mobile phone), a tablet computer, a notebook computer, a palm computer, a Mobile Internet Device (MID), a wearable device, a Virtual Reality (VR) device, an Augmented Reality (AR) device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote operation (remote medical supply), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation security (transportation safety), a wireless terminal in city (city), a wireless terminal in smart home (smart home), a cellular phone, a cordless phone, a session initiation protocol (session initiation protocol) mobile phone, a PDA phone, a wireless local loop (wireless local) local station, a personal digital assistant (SIP) device, and a wireless terminal with wireless communication function, A computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a 5G network, or a terminal device in a Public Land Mobile Network (PLMN) for future evolution, and the like, which are not limited in this embodiment of the present application.

By way of example and not limitation, in the embodiments of the present application, the terminal device may also be a wearable device. Wearable equipment can also be called wearable intelligent equipment, is the general term of applying wearable technique to carry out intelligent design, develop the equipment that can dress to daily wearing, like glasses, gloves, wrist-watch, dress and shoes etc.. A wearable device is a portable device that is worn directly on the body or integrated into the clothing or accessories of the user. The wearable device is not only a hardware device, but also realizes powerful functions through software support, data interaction and cloud interaction. The generalized wearable smart device includes full functionality, large size, and can implement full or partial functionality without relying on a smart phone, such as: smart watches or smart glasses and the like, and only focus on a certain type of application functions, and need to be used in cooperation with other devices such as smart phones, such as various smart bracelets for physical sign monitoring, smart jewelry and the like.

In addition, in the embodiment of the present application, the terminal device may also be a terminal device in an internet of things (IoT) system, where IoT is an important component of future information technology development, and a main technical feature of the present application is to connect an article with a network through a communication technology, so as to implement an intelligent network with interconnected human-computer and interconnected objects.

In addition, the network device in the embodiment of the present application may be a device for communicating with a terminal device, and the network device may also be referred to as an access network device, a radio access network device, or a base station, and may be a TRP (transmission reception point), a base station (BTS) in a global system for mobile communications (GSM) system or a Code Division Multiple Access (CDMA) system, a base station (NodeB, NB) in a Wideband Code Division Multiple Access (WCDMA) system, an evolved base station (evolved NodeB, eNB, or eNodeB) in the LTE system, a Base Station Controller (BSC), a base transceiver station (NodeB, BTS), a home base station (e.g., a home, or base station), a base station unit (HNB), etc., the network device may also be a wireless controller in a Cloud Radio Access Network (CRAN) scene, or the network device may be a relay station, an access point, a vehicle-mounted device, a wearable device, a network device in a 5G network, or a network device in a PLMN network that evolves in the future, or may be an Access Point (AP) in a WLAN, or may be a new radio node b (gNB) in a new radio system (NR) system, which is not limited in the embodiment of the present application.

In one network configuration, a network device may include a Centralized Unit (CU) node, or a Distributed Unit (DU) node, or a RAN device including a CU node and a DU node, or a control plane CU node (CU-CP node) and a user plane CU node (CU-UP node), and a RAN device of a DU node.

The network device provides a service for the terminal device through a cell or a transceiver in the cell, the terminal device communicates with the cell or a transceiver in the cell through a transmission resource (e.g., a frequency domain resource, or a spectrum resource, or a video resource) allocated by the network device, the cell may be a cell corresponding to the transceiver, the cell may belong to a macro base station (e.g., macro eNB or macro gNB), or may belong to a base station corresponding to a small cell (small cell), and the small cell herein may include: urban cell (metro cell), micro cell (microcell), pico cell (pico cell), femto cell (femtocell), etc., which have the characteristics of small coverage and low transmission power, and are suitable for providing high-rate data transmission service.

Fig. 1 is a schematic diagram of a system 100 to which a handover method according to an embodiment of the present invention can be applied. As shown in fig. 1, the communication system 100 may include at least two base stations, such as base station 1 and base station 2 shown in fig. 1. The communication system 100 may also include at least one terminal, such as terminal 1, terminal 2, terminal 3, and terminal 4 shown in fig. 1. The base station and the terminal may communicate over a wireless link. For example, when the terminal 1 is located within the coverage of the base station 1, the terminal 1 may perform wireless communication with the base station 1, and when the terminal 1 is located within the coverage of the base station 2, the terminal 1 may perform wireless communication with the base station 2. In the embodiment of the present application, a terminal communicating with a base station may be understood as a terminal communicating with a cell under the base station, for example, a cell 1 in fig. 1 belongs to a cell under the base station 1, a cell 2 in fig. 1 belongs to a cell under the base station 2, a base station 1 communicating with a terminal 1 may be understood as a base station 1 and a terminal 1 communicating through a wireless resource provided by the cell 1, and a base station 2 communicating with a terminal 1 may be understood as a base station 1 and a terminal 1 communicating through a wireless resource provided by the cell 1. The terminal 2, the terminal 3, and the terminal 4 are located within the coverage of the base station 2, and can perform wireless communication with the base station 2.

In fig. 1, as the terminal device 1 gradually moves from the coverage of one cell 1 to the coverage of a cell 2, or due to reasons such as the need to adjust the wireless transmission traffic load of the cell 1, in order to ensure the continuity of communication and the quality of service, the system needs to transfer the communication link between the terminal device 1 and the cell 1 to the cell 2, that is, the serving base station of the terminal device 1 needs to be switched from the base station 1 to the base station 2. In the handover process, the terminal device 1 needs to perform random access with the cell 2, which may cause a delay in data transmission.

The embodiment of the application provides a communication method, which can determine parameters for communication between a terminal device 1 and a cell 2 in advance in a switching process, and the terminal device 1 can skip a random access process to communicate with the cell 2 under a base station 2, thereby reducing signaling overhead and data transmission delay.

Some terms referred to in the embodiments of the present application are explained first below:

1. timing Advance (TA)

TA may be understood as that, in order to avoid interference between uplink transmissions of different terminals in a cell, a base station may require that uplink transmissions of different terminals in the cell arrive at the base station at the same time or within a certain time range.

Each terminal may have a respective TA, and from the perspective of the terminal, the TA may be understood as a time offset between when the terminal receives downlink data and when the terminal transmits uplink data. Due to different transmission delays of different terminals, the TAs of different terminals may be different, for example, a terminal farther from the base station has a larger transmission delay, and needs to send an uplink transmission earlier than a terminal closer to the base station.

The base station may control the TA of each terminal, so as to control the time for the uplink transmissions of different terminals to reach the base station to be the same or within a certain time range.

Alternatively, TA may be understood as that the base station may control the time when the uplink transmission of the terminal arrives at the base station, so that the time resource of the uplink transmission is the same as or within the error range allocated by the base station.

As wireless communication advances, the TA may have other explanations, which are not limited in this application.

The contents of the TA can be referred to in the third Generation partnership project (3 GPP) (technical specification, TS)38.211 version (version, V)15.0.0, section 4.3, for related content.

2. Initial Transmission Power (ITP)

It can be understood that the power of the uplink transmission sent by the terminal to the base station, for example, the power of the uplink transmission sent by the terminal to the base station for the first time.

The method provided by the embodiment of the present application is described below, where the source base station may be the base station 1 in fig. 1, the target base station may be the base station 2 in fig. 1, the first terminal may be the terminal 1 in fig. 1, and the second terminal may be one or more of the terminal 2, the terminal 3, and the terminal 4 in fig. 1.

Fig. 2 is a schematic flow chart of a communication method 200 of the present application. Hereinafter, a communication method 200 provided by the embodiment of the present application is described with reference to fig. 2, where the method 200 includes:

step 210: the source base station transmits first information to the target base station, the first information including one or more of measurement result information of a downlink between the first terminal and the target base station and position information of the first terminal.

The first information is used to determine a timing advance for uplink transmission between the first terminal and the target base station, and for convenience of description, the timing advance for uplink transmission between the first terminal and the target base station is referred to as a first timing advance.

Alternatively, the measurement result information of the downlink between the first terminal and the target base station may include any one or more of Reference Signal Receiving Power (RSRP), Signal to Noise Ratio (SNR), Received Signal Strength Indication (RSSI), Reference Signal Receiving Quality (RSRQ), and the like.

Alternatively, the location information of the first terminal may be information indicating the location of the first terminal, and may be, for example, geographic coordinates of the first terminal, such as a longitude and latitude location.

Taking the determination of the timing advance or the initial transmission power according to the first information as an example, it should be noted that the first information may also be used for other purposes, for example, to determine other parameter information for the first terminal to communicate with the target base station, which is not limited in the embodiment of the present application, and steps 220 to 240 are optional.

Step 220: and the target base station determines the first timing advance according to the first information.

Optionally, the first information is further used to determine an initial transmit power of uplink transmission between the first terminal and the target base station, and for convenience of description, the initial transmit power of uplink transmission between the first terminal and the target base station is referred to as a first initial transmit power. Step 220 may also include the target base station determining a first initial transmit power based on the first information.

Step 230: and the target base station sends the information of the first timing advance to the source base station.

Optionally, step 230 may further include the target base station sending information of the first initial transmission power to the source base station.

Step 240: and the source base station sends the information of the first timing advance to the first terminal.

Optionally, step 240 may further include the source base station sending information of the first initial transmission power to the first terminal.

Alternatively, step 230 and step 240 may be understood as that the target base station transmits the first timing advance to the first terminal through the source base station.

Alternatively, step 230 and step 240 may be understood as that the target base station transmits the first initial transmission power to the first terminal through the source base station.

Optionally, the method 200 may further include the first terminal performing uplink transmission with the target base station according to the first timing advance, for example, the first terminal sends uplink data to the target base station according to the first timing advance.

Optionally, the method 200 may further include the first terminal performing uplink transmission with the target base station according to the first initial transmission power, for example, the first terminal sending uplink data to the target base station according to the first initial transmission power.

Next, how the target base station determines the first timing advance according to the first information in step 220 is described.

As a first implementation manner, the target base station may determine a distance (D) between the first terminal and the target base station according to the first information, and then determine the first timing advance according to the distance between the first terminal and the target base station.

Regarding how the target base station determines the distance between the first terminal and the target base station from the first information, the following provides several examples:

in a first example, the first information comprises measurement result information of a downlink between the first terminal and the target base station.

The target base station may determine a Path Loss (PL) between the target base station and the first terminal according to the measurement result information, and determine a distance between the first terminal and the target base station according to the path loss.

In a second example, the first information comprises location information of the first terminal.

The target base station may determine a distance between the first terminal and the target base station according to the location information of the first terminal and the location information of the target base station.

In a third example, the first information includes measurement result information of a downlink between the first terminal and the target base station and location information of the first terminal.

The target base station may determine a distance between the first terminal and the target base station according to the measurement result information of the downlink between the first terminal and the target base station (specifically, refer to the first example), and determine a distance between the first terminal and the target base station according to the location information of the first terminal (specifically, refer to the second example), then compare the distances between the first terminal and the target base station calculated by the two implementation manners, and select one as the distance between the first terminal and the target base station, or obtain the distance between the first terminal and the target base station by using a certain algorithm (for example, averaging) on the basis of the distances between the first terminal and the target base station calculated by the two implementation manners, which is not limited by the embodiment of the present application.

As a second implementation manner, the target base station may obtain a mapping relationship between the second information and the second timing advance, and then determine the first timing advance according to the mapping relationship and the first information.

It can be understood that the second information and the second timing advance may be information of a terminal that has historically accessed the target base station, and the target base station may obtain the first timing advance according to the historical information.

The second information includes one or more of measurement result information of a downlink between the second terminal and the target base station and position information of the second terminal, and the second timing advance is a timing advance of uplink transmission between the second terminal and the target base station.

Alternatively, the target base station may obtain the second information when communicating with the second terminal, for example, the second terminal may establish a communication connection with the target base station, and the second terminal may report one or more of measurement result information of a downlink between the second terminal and the target base station and location information of the second terminal to the target base station.

Alternatively, the target base station may acquire the timing advance of the second terminal in a random access procedure of the second terminal, or the target base station may acquire the timing advance of the second terminal after performing Radio Resource Control (RRC) connection with the second terminal.

Alternatively, the target base station may obtain the mapping relationship from other network devices, for example, other base stations, core network elements, or servers.

Optionally, in a second implementation manner, the second terminal may be one or more terminals, and the mapping relationship between the second information and the second timing advance may be understood as a mapping relationship between a plurality of second information and a plurality of second timing advances, for example, one-to-one, one-to-many, or many-to-one, which is not limited in this embodiment of the present application.

Optionally, the second terminal may include the first terminal, for example, the first terminal first communicates with the target base station, then switches to another base station, and then switches from another base station to the target base station, where the second information may include one or more of measurement result information of a downlink when the first terminal first communicates with the target base station and location information of the second terminal, where the second timing advance is a timing advance of uplink transmission when the first terminal first communicates with the target base station.

Next, how the target base station determines the first initial transmission power according to the first information in step 220 is described.

As a first implementation, the target base station may determine a path loss between the first terminal and the target base station according to the first information, and then determine the first initial transmission power according to the path loss between the first terminal and the target base station.

Regarding how the target base station determines the path loss between the first terminal and the target base station from the first information, the following provides several examples:

The target base station may determine a path loss between the target base station and the first terminal according to the measurement result information.

The target base station may determine a distance between the first terminal and the target base station according to the location information of the first terminal and the location information of the target base station, and determine a path loss between the first terminal and the target base station according to the distance between the first terminal and the target base station.

The target base station may determine, according to the measurement result information of the downlink between the first terminal and the target base station, a path loss between the first terminal and the target base station (specifically, refer to the first example), and determine, according to the location information of the first terminal, a path loss between the first terminal and the target base station (specifically, refer to the second example), then compare the path losses between the first terminal and the target base station calculated by the two implementation manners, and select one path loss as the path loss between the first terminal and the target base station, or obtain, on the basis of the path losses between the first terminal and the target base station calculated by the two implementation manners, the path loss between the first terminal and the target base station by using a certain algorithm (for example, averaging), which is not limited by the embodiment of the present application.

As a second implementation manner, the target base station may obtain a mapping relationship between the second information and the second initial transmission power, and then determine the first initial transmission power according to the mapping relationship and the first information.

It is to be understood that the second information and the second initial transmission power may be information of terminals that have been historically accessed to the target base station, and the target base station may obtain the first initial transmission power according to the historical information.

The second information includes one or more of measurement result information of a downlink between the second terminal and the target base station and position information of the second terminal, and the second initial transmission power is initial transmission power of uplink transmission between the second terminal and the target base station.

Optionally, the target base station may obtain the second information when communicating with the second terminal, for example, the second terminal may establish a communication connection with the target base station, and the second terminal may report one or more of measurement result information of a downlink between the second terminal and the target base station and location information of the second terminal to the target base station.

Optionally, the target base station may obtain the initial transmit power of the second terminal in a random access procedure of the second terminal, or the target base station may obtain the initial transmit power of the second terminal after performing an RRC connection with the second terminal.

Alternatively, the second terminal may include the first terminal, for example, the first terminal first communicates with the target base station, then switches to another base station, and then switches from another base station to the target base station, where the second information may include one or more of measurement result information of a downlink when the first terminal first communicates with the target base station and position information of the second terminal, where the second initial transmission power may be understood as an initial transmission power of an uplink transmission when the first terminal first communicates with the target base station.

In the switching process, the embodiment of the application can determine parameters, such as timing advance and initial transmitting power, of the first terminal for communicating with the target base station in advance, and the first terminal can skip the random access process to transmit uplink data with the target base station, so that signaling overhead and data transmission delay are reduced.

Fig. 3 is a schematic flow chart of a communication method 300 of the present application, and the embodiment shown in fig. 3 can be regarded as a further illustration of a first example of the first implementation in the embodiment shown in fig. 2. Hereinafter, a communication method 300 provided by the embodiment of the present application is described with reference to fig. 3, where the method 300 includes:

in step 310, the source base station sends measurement configuration information (for example, RRC reconfiguration information), which may include parameters such as measurement object, report configuration, measurement identifier, and the like, to the first terminal.

In step 311, the first terminal measures a series of cells according to the measurement configuration information and forms a measurement report, where the measurement report can report various events to the source base station, for example, the signal strength of the current serving cell is lower than a certain threshold and the signal strength of the target cell is higher than a certain threshold.

In step 312, the first terminal sends a measurement report to the source base station, where the measurement report includes measurement results of the first terminal on a series of cells. Specifically, the measurement of a series of cells may refer to: measurements are made of downlink signals (e.g., reference signals) from a cell, specifically, from access devices providing the cell.

For example, the measurement result may include any one or more of reference signal received power, signal-to-noise ratio, received signal strength indication, or reference signal received quality of each cell.

In step 313, the source base station determines whether a handover of the serving base station of the first terminal is required according to the measurement result, and further may determine a target cell of the first terminal and determine a base station to which the target cell belongs as the target base station.

For example, when it is determined that the signal strength of the current serving cell is below a certain threshold and the signal strength of a certain neighbor cell is above a certain threshold, the source base station makes a handover decision and may determine the neighbor cell as a target cell to which the first terminal is to be handed over, while determining the base station to which the neighbor cell belongs as a target base station to which the handover is to be handed over. At this time, the source base station may send a handover request message to the target base station.

In step 320, the source base station sends a handover request message to the target base station, where the handover request message carries measurement result information of a downlink between the first terminal and the target base station.

The first timing advance may be determined from the measurement information. For example, the measurement result information may include information of the received power of the reference signal of the target cell measured by the first terminal.

Specifically, the measurement report includes measurement results of the terminal device for a series of cells, and after the source base station determines the target cell (for example, the cell with the best signal may be determined as the target cell), the source base station may acquire the received power of the reference signal of the target cell, and send information of the received power of the reference signal to the target base station, and the target base station may determine the first timing advance according to the information of the received power of the reference signal.

It should be understood that the information of the received power of the reference signal may also be information of the received power (BRSRP) of the reference signal of a certain beam, which is not limited in this application.

Optionally, the measurement result information can also be used to determine the first initial transmit power.

Optionally, for sending the measurement result information, the measurement result information of the present application may also be sent separately, or may also be carried in other information and sent to the target base station, which is not limited in the present application.

In step 330, the target base station determines a first timing advance according to the measurement result information of the downlink between the first terminal and the target base station.

Optionally, the target base station receives the handover request message, and after confirming that the first terminal is allowed to access, the target base station may determine the first timing advance according to the measurement result information.

Alternatively, the measurement result information may be information of the received power RSPR of the reference signal. The target base station may determine a path loss PL between the target base station and the first terminal according to a difference between a power RSRP of a reference signal of the target cell and a received power RSRP of the reference signal, and determine a distance D between the first terminal and the target base station according to the path loss PL.

Specifically, according to different scenarios, the target base station may select a path loss formula under different models to calculate the distance D between the first terminal and the target base station, such as a free space propagation model, an oromura-hart model, or a Hata model.

Further, after determining the distance D (unit: meter) between the first terminal and the target base station, T can be calculated according to the following formula: and T is 2X D/c. Wherein, T is the sum (unit: second) of one uplink transmission time and one downlink transmission time between the first terminal and the target base station, and c is the electromagnetic wave propagation speed (unit: meter/second).

After T is obtained, the timing advance TA is easily obtained by performing conversion according to the definition of the timing advance.

For example, TA may be 16Ts, 1Ts 1/(15000 2048) (unit: sec), and the value of TA is an integer between 0 and 1282. The timing advance TA is the first timing advance.

Optionally, the first initial transmission power may also be determined according to the received power information of the reference signal.

Specifically, the target base station may determine a path loss PL between the target base station and the first terminal according to a difference between the reference signal power RSRP and the reference signal received power RSRP, and obtain the first initial transmission power ITP according to a sum of the path loss PL and a Target Received Power (TRP) expected to be received by the target base station.

In step 340, the target base station sends a handover confirmation message to the source base station, where the handover confirmation message includes information of the first timing advance.

In step 350, the source base station sends a handover command message to the first terminal, where the handover command message includes information of the first timing advance.

In steps 340 and 350, since no RRC connection has been established between the first terminal and the target base station, the target base station may send the first timing advance information to the first terminal through the source base station. Specifically, the target base station sends a handover confirmation message to the source base station after confirming that the access of the first terminal is allowed and determining the first timing advance, where the handover confirmation message may include information of the first timing advance. After receiving the information of the first timing advance, the source base station sends a handover command message to the first terminal, where the handover command message may include the information of the first timing advance. Step 340 and step 350 may be understood as that the target base station transmits the first timing advance information to the first terminal through the source base station.

The content contained within the handover command message (which may be, for example, an RRC reconfiguration message) may be from the handover confirm message.

It should be understood that the information of the first timing advance may also be sent to the source base station and/or the first terminal separately, or may also be sent to the source base station and/or the first terminal in other messages, which is not limited in this application.

Optionally, the target base station may further send the information of the first initial transmission power to the first terminal through the source base station. For example, the information of the first initial transmission power may be carried in a handover confirm message and a handover command message.

In addition, the information of the first initial transmission power may also be sent to the source base station and/or the first terminal separately, or may also be sent to the source base station and/or the first terminal by being carried in other messages, which is not limited in this application.

Optionally, the handover command message may further include a synchronization signal block Index (SSB Index).

Specifically, in the 5G system, since high frequency transmission is used, energy of waves is easily lost during propagation, and if the waves are transmitted in various directions as in the 4G system, the energy is wasted and the effect is not good. Therefore, in the 5G system, a new characteristic of beamforming (beamforming) is introduced, i.e. an antenna is allowed to transmit signals in a fixed direction. Generally, the random access configuration in the handover command message may carry a synchronization signal block index, and the terminal device determines the transmission direction of the signal according to the synchronization signal block index. In the technical scheme of the application, the handover command message does not include the random access configuration, so that the synchronization signal block index can be carried in the handover command message separately.

In addition, the synchronization signal block index may also be sent to the first terminal separately, or sent to the first terminal by being carried in other messages, which is not limited in this application.

In step 360, the first terminal receives the handover command message, and performs uplink data transmission with the target base station according to the first timing advance information in the handover command message.

The first terminal may perform uplink data transmission with the target cell based on the first timing advance, for example, send an RRC reconfiguration complete message to the target base station through the target cell.

In addition, the first terminal may also determine a signal transmission direction according to the synchronization signal block index in the handover command message, and transmit a data signal to the signal transmission direction, so as to perform uplink data transmission with the target cell.

Optionally, the first terminal may perform uplink data transmission with the target base station based on the first timing advance and the first initial transmit power.

Optionally, if the handover command message does not include the information of the first initial transmission power, the first terminal may calculate the first initial transmission power by itself. For example, the first terminal may determine a path loss PL between the target base station and the first terminal according to a difference between the reference signal power RSRP and the reference signal received power RSRP, and obtain the first initial transmission power ITP according to a sum of the path loss PL and a power TRP expected to be received by the target base station.

Optionally, if uplink data transmission fails (for example, the number of times of hybrid automatic repeat request (HARQ) failure reaches the upper limit N times), the first terminal may enter a random access procedure, that is, the first terminal may initiate random access to the target base station at this time, so as to avoid increasing delay.

According to the embodiment of the application, the first timing advance and the first initial transmitting power can be determined through the target base station, the related information is sent to the first terminal, the first terminal can skip a random access program (the time of the random access program is about dozens of milliseconds), the related parameters are directly used for establishing connection with the target base station, and uplink data transmission is carried out, so that signaling overhead is reduced, time delay is reduced, and user experience is improved. In addition, the embodiment of the application also shows a good rollback mechanism, when the uplink transmission fails, the first terminal can be caused to rollback to the random access program, and the time delay can be prevented from being increased.

Fig. 4 is a schematic flow chart of a communication method 400 of the present application, and the embodiment shown in fig. 4 can be regarded as a further description of a second example of the first implementation in the embodiment shown in fig. 2. Hereinafter, a communication method 400 provided by the embodiment of the present application is described with reference to fig. 4, where the method 400 includes:

in step 410, the source base station sends measurement configuration information to the first terminal, where the measurement configuration information carries second indication information, and the second indication information is used to indicate the first terminal to report its own location information.

In step 411, the first terminal measures a series of cells according to the measurement configuration information and forms a measurement report, and at the same time, the first terminal determines its location and generates its location information.

In step 412, the first terminal sends a measurement report to the source base station, where the measurement report includes location information of the first terminal.

In step 413, the source base station determines whether a serving base station of the first terminal needs to be handed over according to the measurement result, and determines a target cell of the first terminal, and determines a base station to which the target cell belongs as the target base station.

The above steps 410, 411, 412, 413 may be understood with reference to steps 310, 311, 312, 313 in the method 300, the differences being set forth herein.

In this embodiment, the measurement configuration information sent by the source base station to the first terminal further includes second indication information, where the second indication information is used to indicate that the first terminal reports its own location information to the source base station, and after receiving the measurement configuration information carrying the second indication information, the first terminal not only starts to perform measurement, but also determines its current location, and carries the location information in a measurement report and reports the location information to the source base station.

Alternatively, the second indication information may be a string of specific codes, or a bit of 0 or 1, or distinguished by NULL and non-NULL, as specified by the protocol or system.

While the second indication information is described as being carried in the measurement configuration information, it should be understood that the second indication information may be carried in other messages in the prior art, or the source base station may separately send the second indication information to the first terminal, which is not limited in this application.

In step 420, the source base station sends a handover request message to the target base station, where the handover request message carries the location information of the first terminal.

Specifically, the source base station may obtain a position of the first terminal, and send information of the position to the target base station, and may determine the first timing advance according to the information of the position of the first terminal. For example, the location of the first terminal may be the current location of the first terminal.

Optionally, the position information can also be used to determine the first initial transmit power.

Optionally, for the sending of the location information, the measurement result information of the present application may also be sent separately, or may also be carried in other information and sent to the target base station, which is not limited in the present application.

In step 430, the target base station determines a first timing advance according to the location information of the first terminal.

Specifically, the target base station receives the handover request message, and after confirming that the first terminal is allowed to access, the target base station may determine the first timing advance according to the location information.

The target base station can determine the distance D between the first terminal and the self-position according to the position of the first terminal and the self-position.

Optionally, the target base station may further determine the first initial transmission power according to the location information of the first terminal.

The target base station can determine the distance D between the first terminal and the position of the target base station according to the position of the first terminal and the position of the target base station, and according to different scenes, the target base station can select path loss formulas under different models to calculate the path loss PL between the first terminal and the target base station, such as a free space propagation model, an Oncun-Harta model or a Hata model. And then obtaining the first initial transmission power ITP according to the sum of the path loss PL and the expected received power TRP of the target base station.

In step 440, the target base station sends a handover confirmation message to the source base station, where the handover confirmation message includes information of the first timing advance.

In step 450, the source base station sends a handover command message to the first terminal, where the handover command message includes information of the first timing advance.

In step 460, the first terminal receives the handover command message, and performs uplink data transmission with the target base station according to the first timing advance information in the handover command message.

The steps 440, 450, and 460 refer to the steps 340, 350, and 360 of the method 200, and are not described herein again.

It should be understood that the method 400 provided in this embodiment may also be used in combination with the foregoing method 300, specifically, the first timing advance may be determined jointly according to the two timing advances calculated by the methods 400 and 300, for example, an average value of the two timing advances may be determined as the first timing advance, or the first timing advance may be obtained by another algorithm on the basis of the two timing advances calculated by the methods 400 and 300, which is not limited in this embodiment of the present application.

Fig. 5 is a schematic flow chart of a communication method 500 of the present application, and the embodiment shown in fig. 5 can be regarded as a further description of the second implementation manner in the embodiment shown in fig. 2. Hereinafter, a communication method 500 provided by the embodiment of the present application is described with reference to fig. 5, where the method 500 includes:

in step 510, the source base station transmits measurement configuration information to the first terminal.

In step 511, the first terminal measures a series of cells according to the measurement configuration information and forms a measurement report.

In step 512, the first terminal transmits a measurement report to the source base station.

In step 513, the source base station determines whether a serving base station of the first terminal needs to be handed over according to the measurement result, and determines a target cell of the first terminal, and determines a base station to which the target cell belongs as the target base station.

In step 520, the source base station sends a handover request message to the target base station, where the handover request message carries the first information.

The above steps 510, 511, 512, 513, and 520 can be understood with reference to the steps 310, 311, 312, 313, and 320 in the method 300, and are not described herein again.

In step 530, the target base station determines a first timing advance according to the first information and the mapping relation.

Specifically, the target base station may first obtain a mapping relationship, where the mapping relationship is a mapping relationship between second information and a second timing advance, the second information includes one or more of measurement result information of a downlink between the second terminal and the target base station and position information of the second terminal, and the second timing advance is a timing advance of uplink transmission between the second terminal and the target base station; and determining the first timing advance according to the mapping relation and the first information.

The second terminal may be a terminal device that has established a connection with the target base station, and the second timing advance may be a timing advance used by the second terminal and the target base station to successfully perform uplink data transmission.

Optionally, the second terminal may be one or more terminals, and the mapping relationship between the second information and the second timing advance may be understood as a mapping relationship between a plurality of second information and a plurality of second timing advances, for example, one-to-one, one-to-many, or many-to-one, which is not limited in this embodiment of the present application.

Optionally, the target base station may generate the mapping relationship according to a correspondence between a plurality of second information reported by the second terminal and a plurality of second timing advance information. The reporting of the corresponding relationship by the second terminal may further include reporting the corresponding relationship by the second terminal through another base station.

Optionally, the target base station may send indication information to the connected second terminals (for example, the indication information may be broadcast to each second terminal), where the indication information is used to indicate that the plurality of second terminals report the correspondence between the plurality of second information and the plurality of second timing advances, the terminal device reports the correspondence to the target base station after receiving the indication information, and the target base station may generate the mapping relationship according to the correspondence after receiving the correspondence.

Optionally, the existing mapping relationship may be perfected according to the corresponding relationship.

Optionally, the target base station may generate the mapping relationship according to a correspondence between second information and a second timing advance, which are locally stored.

Optionally, the correspondence between the plurality of second information and the plurality of second timing advance information may be obtained by an operator drive test.

Alternatively, the plurality of second information and the plurality of second timing advance information may have a one-to-one correspondence relationship, each second information corresponding to each second timing advance. For example, the second information #1 may include information of received power RSRP #1 of the reference signal measured at the location #1, or coordinate #1 of the location #1, and the corresponding timing advance TA #1 is a timing advance used for successfully performing uplink data transmission with the target base station at the location # 1.

For example, the correspondence relationship between the plurality of second information and the plurality of second timing advance information may be a correspondence relationship between the received power of the reference signal transmitted by the plurality of target base stations and the plurality of timing advances.

For another example, the correspondence relationship between the plurality of second information and the plurality of second timing advance information may be a correspondence relationship between positions of the plurality of second terminals and the plurality of timing advances.

For example, referring to table 1, the mapping relationship may exist in the form of a correspondence table.

Table 1:

RSRP value	RSRP#1	RSRP#2	RSRP#3	…	RSRP#n
						Position coordinates	coordinate#1	coordinate#2	coordinate#3	…	coordinate#n
TA value	TA#1	TA#2	TA#3	…	TA#n

Table 1 shows the correspondence between the received power of n reference signals and n TA values, and also shows the correspondence between n position coordinates and n TA values.

In this case, the target base station may determine the timing advance corresponding to the first information as the first timing advance according to the mapping relationship # a (i.e., the correspondence table).

For example, if the parameter indicated by the first information is RSRP #1 or cordinate #1, the timing advance TA #1 corresponding to the first information may be determined as the first timing advance.

It should be understood that the scales (or parameters) in table 1 are discrete, and the data measured by the terminal device is continuous, so that the parameter indicated by the first information may not be included in the mapping relationship (i.e. the correspondence table), and in this case, through a certain algorithm, the first timing advance may also be determined according to the mapping relationship.

For example, the parameter indicated by the first information is RSRP #1-2 which is a parameter between RSRP #1 and RSRP #2, at this time, TA #1-2 may be calculated by a certain algorithm according to TA #1 and TA #2 corresponding to the parameter, and the TA #1-2 is determined as the first timing advance.

For another example, the parameter indicated by the first information is a parameter cordinate #1-2 between cordinate #1 and cordinate #2, at this time, TA #1-2 may be obtained by a certain algorithm according to TA #1 and TA #2 corresponding to the parameter, and the TA #1-2 is determined as the first timing advance.

It should be understood that the algorithm for obtaining TA #1-2 is not limited in the present application, and TA #1-2 can be obtained by averaging TA #1 and TA #2, as an example.

It should be understood that the above table 1 is only for example, and the application is not limited to the existence form of the mapping relation # a or the possible existence. For example, table 1 may show only the correspondence between the received power of n reference signals and n TA values, or only the correspondence between n position coordinates and n TA values, in other words, the contents of row 1 and row 2 in table 1 may not be present at the same time, or only either one of them may be present.

Optionally, the target base station may further determine the first initial transmission power according to the first information and the mapping relationship.

Specifically, the mapping relationship is a mapping relationship between second information and second initial transmit power, the second initial transmit power is an initial transmit power of uplink transmission between the second terminal and the target base station, and the target base station may determine the first initial transmit power according to the mapping relationship and the first information.

Similarly, the generation manner of the mapping relationship between the second information and the second initial transmission power is basically the same as the generation manner of the mapping relationship between the second information and the second timing advance, and the method for determining the first initial transmission power according to the mapping relationship and the first information is also basically the same as the method for determining the first timing advance according to the mapping relationship and the first information, and is not described herein again.

It should be understood that in practical communication applications, the uplink path loss PL and the downlink path loss PL are not the same (it is actually assumed in the method 300 that the uplink path loss PL and the downlink path loss PL are the same), and similarly, in the foregoing methods 300 and 400, the first timing advance is calculated according to the distance between the first terminal and the target base station without considering the influence of an obstacle that may exist between the first terminal and the target base station, and therefore, the first timing advance calculated by the methods 300 and 400 may not be accurate enough. In the method 500 provided in this embodiment, the first timing advance is determined according to the past empirical value, so that the accuracy of the result can be improved.

The methods of determining the first timing advance provided by the foregoing methods 300, 400, 500 may be used alone or may be used in combination. Specifically, the first timing advance may be determined by one or more of the three methods described above.

Alternatively, a plurality of timing advances may be determined by a plurality of the three methods described above, and the first timing advance may be determined based on the plurality of timing advances, for example, by averaging the plurality of timing advances to obtain the first timing advance.

Alternatively, the first timing advance calculated in methods 300 and 400 may be corrected by the first timing advance determined in method 500.

If the first terminal successfully accesses the target base station by the first timing advance calculated by the methods 300 and 400, the mapping relationship may be refined (or corrected) by the calculated first timing advance, for example, the mapping relationship is supplemented with the corresponding relationship between the first information and the first timing advance.

Fig. 5 above describes a process of acquiring, by the target base station, the first timing advance and/or the first initial transmission power according to the mapping relationship, it should be noted that the target base station may broadcast the mapping relationship (for example, through a system message), the first terminal may receive the mapping relationship, and then the first terminal acquires the first timing advance and/or the first initial transmission power according to the mapping relationship.

Fig. 6 is a schematic flow chart diagram of a communication method 600 of the present application. Hereinafter, a communication method 600 provided by an embodiment of the present application is described with reference to fig. 6, where the method 600 includes:

step 610: the target base station generates first indication information.

The first indication information may be used to indicate that the first terminal determines the first timing advance.

Optionally, the first indication information may also be used to instruct the first terminal to determine the first initial transmission power.

Optionally, the first indication information may carry location information of the target base station.

Alternatively, the first indication information may display an indication, for example, as specified by a protocol or system, as a string of specific codes, or as a bit of 0 or 1, or as distinguished by NULL and non-NULL. Alternatively, the first indication information may implicitly indicate, for example, that the target base station sends location information of the target base station to the first terminal through the source base station, and implicitly indicates that the first terminal determines the first timing advance and/or the first initial transmit power.

The following description takes the first indication information for indicating the first terminal to determine the first timing advance or the first initial transmit power as an example, it should be noted that the first indication information may also be used for other purposes, for example, other parameter information for indicating the first terminal to determine that the first terminal communicates with the target base station, which is not limited in this embodiment of the application, and step 640 is optional.

Step 620: the target base station sends first indication information to the source base station.

Step 630: the source base station sends first indication information to the first terminal.

Alternatively, step 620 and step 630 may be understood as that the target base station transmits the first indication information to the first terminal through the source base station.

Step 640: the first terminal receives the first indication information and determines a first timing advance according to the indication of the first indication information.

Optionally, the first terminal receives the first indication information, and determines the first initial transmission power according to the indication of the first indication information.

How the first terminal determines the first timing advance in step 640 will be described below.

As a first implementation, the first terminal may determine a distance between the first terminal and the target base station, and then determine the first timing advance according to the distance between the first terminal and the target base station.

With respect to how the first terminal determines the distance between the first terminal and the target base station, several examples are provided below:

in a first example, the first terminal may determine a path loss between the target base station and the first terminal from the measurement result information of the downlink between the first terminal and the target base station, and determine a distance between the first terminal and the target base station from the path loss.

In a second example, the first terminal may determine the distance between the first terminal and the target base station according to the location information of the first terminal and the location information of the target base station.

In a third example, the first terminal may determine a distance between the first terminal and the target base station according to downlink measurement result information between the first terminal and the target base station (specifically, refer to the first example), and determine a distance between the first terminal and the target base station according to location information of the first terminal (specifically, refer to the second example), and then compare the distances between the first terminal and the target base station calculated by the two implementations, and select one as the distance between the first terminal and the target base station, or obtain the distance between the first terminal and the target base station by using an algorithm (for example, averaging) on the basis of the distances between the first terminal and the target base station calculated by the two implementations, which is not limited by the embodiment of the present application.

As a second implementation manner, the first terminal may obtain a mapping relationship between the second information and the second timing advance, and then determine the first timing advance according to the mapping relationship and the measurement result information of the downlink between the first terminal and the target base station and/or the location information of the first terminal.

Alternatively, the mapping relationship may be generated by the target base station and sent to the first terminal through the source base station in advance. Or, alternatively, the target base station may broadcast the mapping relationship, and the first terminal may receive the system message and obtain the mapping relationship.

The relevant content of the mapping relationship may refer to the relevant description of step 220, which is not described herein again in this embodiment.

How the first terminal determines the first initial transmit power in step 640 will be described below.

As a first embodiment, the first terminal may determine a path loss between the first terminal and the target base station, and then determine the first initial transmission power according to the path loss between the first terminal and the target base station.

With respect to how the first terminal determines the path loss between the first terminal and the target base station, several examples are provided below:

in a first example, the first terminal may determine a path loss between the target base station and the first terminal according to the measurement result information.

In a second example, the first terminal may determine a distance between the first terminal and the target base station according to the location information of the first terminal and the location information of the target base station, and determine a path loss between the first terminal and the target base station according to the distance between the first terminal and the target base station.

In the third example, the first terminal may determine the path loss between the first terminal and the target base station according to the measurement result information of the downlink between the first terminal and the target base station, respectively (refer to the first example in particular), and determining the path loss between the first terminal and the target base station according to the position information of the first terminal (refer to the second example in particular), then comparing the path loss between the first terminal and the target base station calculated by the two implementation methods, and selecting one as the path loss between the first terminal and the target base station, or, on the basis of the path loss calculated between the first terminal and the target base station for both implementations, the path loss between the first terminal and the target base station is obtained through a certain algorithm (for example, averaging), and the embodiment of the present application does not limit the specific algorithm.

As a second implementation manner, the first terminal may obtain a mapping relationship between the second information and the second initial transmission power, and then determine the first initial transmission power according to the mapping relationship and the measurement result information of the downlink between the first terminal and the target base station and/or the location information of the first terminal.

Alternatively, the mapping relationship may be generated by the target base station and sent to the first terminal through the source base station in advance.

In the embodiment, in the handover process, the first terminal can determine parameters, such as timing advance and initial transmission power, for the first terminal to communicate with the target base station in advance, and the first terminal can skip the random access process to perform uplink data transmission with the target base station, thereby reducing signaling overhead and data transmission delay.

Fig. 7 is a schematic flow chart of a communication method 700 of the present application, and the embodiment shown in fig. 7 can be regarded as a further description of the embodiment shown in fig. 6. Hereinafter, a communication method 700 provided by the embodiment of the present application is described with reference to fig. 7, where the method 700 includes:

in step 710, the source base station transmits measurement configuration information to the first terminal.

In step 711, the first terminal measures a series of cells according to the measurement configuration information and forms a measurement report.

In step 712, the first terminal transmits a measurement report to the source base station.

In step 713, the source base station determines whether a serving base station of the first terminal needs to be handed over according to the measurement result, and determines a target cell of the first terminal, and determines a base station to which the target cell belongs as the target base station.

The steps 710, 711, 712, and 713 can be understood with reference to the steps 310, 311, 312, and 313 of the method 300, and are not described herein again.

In step 720, the source base station sends a handover request message to the target base station.

In step 730, the target base station generates first indication information, where the first indication information is used to indicate that the first terminal determines the first timing advance.

Specifically, the target base station receives the handover request message, and first determines not to allow the access of the terminal device according to the number of its own connections, and if so, the target base station may generate first indication information, where the first indication information is used to indicate the first terminal to determine the first timing advance.

Optionally, the first indication information may further instruct the first terminal to determine the first initial transmission power.

In step 740, the target base station sends a handover confirm message to the source base station, where the handover confirm message includes the first indication information.

In step 750, the source base station sends a handover command message to the terminal device, where the handover command message includes the first indication information.

After the target base station confirms that the first terminal is allowed to access and generates the first indication information, the target base station can send the first indication information to the first terminal through the source base station because the RRC connection is not established between the first terminal and the target base station. Specifically, the target base station may send a handover confirmation message to the source base station, and the handover confirmation message may include the first indication information. The source base station sends a handover command message to the first terminal after receiving the first indication information, and the handover command message may include the first indication information.

It should be understood that the first indication information may also be sent to the source base station and/or the first terminal separately, or may also be sent to the source base station and/or the first terminal in other messages, which is not limited in this application.

Optionally, the target base station may also send its own location information to the first terminal through the source base station. The location information of the target base station may be carried in the handover confirm message and the handover command message, or may also be carried in the first indication information. In addition, the location information of the target base station may also be sent to the source base station and/or the first terminal separately, or may also be sent to the source base station and/or the first terminal by being carried in other messages, which is not limited in this application.

In step 751, the first terminal receives the first indication information and determines a first timing advance.

Optionally, the first terminal may determine the first timing advance according to measurement result information of a downlink between the first terminal and the target base station.

Alternatively, the first terminal may determine the first initial transmission power according to measurement result information of a downlink between the first terminal and the target base station.

Reference may be made in particular to the above-mentioned method 200, and to the relevant content of the methods 300, 600, such as the relevant description of the steps 220, 330, 640.

Optionally, the first indication information may include location information of the target base station, and the first terminal may determine the first timing advance according to the location information of the first terminal and the location information of the target base station.

Optionally, the first terminal may determine the first initial transmission power according to the location information of the first terminal and the location information of the target base station.

Reference may be made in particular to the above-mentioned method 200, and to the relevant content of the methods 400, 600, such as the relevant description of the steps 220, 430, 640.

Optionally, when the first terminal needs to determine the first timing advance according to its own position, the first terminal also needs to acquire the position of the target base station, and at this time, the target base station may send information of its own position to the first terminal through the source base station in advance. Alternatively, the source base station itself stores the information of the position of the target base station, and the source base station may directly transmit the information of the position of the target base station to the first terminal. In addition, the information of the position of the target base station may also be stored in the first terminal in advance, which is not limited in the present application.

Optionally, the first terminal may determine the first timing advance according to the mapping relationship and measurement result information of the downlink between the first terminal and the target base station.

Alternatively, the first terminal may determine the first initial transmission power according to the mapping relation and the measurement result information of the downlink between the first terminal and the target base station.

Reference may be made in particular to the above-mentioned method 200 and to the relevant content of the methods 500, 600, for example to the relevant description of steps 220, 530, 640.

In step 760, the first terminal performs uplink data transmission with the target base station according to the first timing advance.

Optionally, the first terminal may perform uplink data transmission with the target cell based on the first timing advance and the first initial transmit power.

If transmission fails (for example, the number of HARQ retransmission failures reaches the upper limit N times), the first terminal may enter a random access procedure, that is, the first terminal may initiate a random access procedure to the target base station at this time, so that an increase in delay may be avoided.

In addition, in step 751, if the first timing advance cannot be determined due to lack of correlation parameters (e.g., location of the target base station) of the first terminal, the random access procedure may be directly initiated.

In this embodiment, the first terminal determines the first timing advance, and performs uplink data transmission with the target base station according to the first timing advance. In this embodiment, the first indication information may indicate that the first terminal determines the first timing advance according to the first information, or may be specified by a system or a protocol, and the first terminal determines the relevant parameter according to the first information, which is not limited in this application.

Fig. 6 to fig. 7 describe that the target base station instructs the first terminal to calculate the first timing advance, it should be noted that the first terminal may be predefined by the communication system to calculate the first timing advance without the target base station sending instruction information, so as to save communication resources; alternatively, the source base station may send the first indication information to the first terminal, which may refer to the relevant contents in fig. 6 to fig. 7.

The communication method provided by the embodiment of the present application is described in detail above with reference to fig. 2 to 7. Hereinafter, a communication device according to an embodiment of the present application will be described in detail with reference to fig. 8 to 10.

Fig. 8 is a schematic structural diagram of a network device. The source base station or the target base station may refer to the structure shown in fig. 8.

The network device includes at least one processor 1511, at least one memory 1512, at least one transceiver 1513, at least one network interface 1514, and one or more antennas 1515. The processor 1511, memory 1512, transceiver 1513, and network interface 1514 are coupled, such as by a bus. The antenna 1515 is connected to the transceiver 1513. The network interface 1514 is used to enable the network device to connect to other communication devices via a communication link. In the embodiment of the present application, the connection may include various interfaces, transmission lines, buses, and the like, which is not limited in this embodiment.

The memory 1512, which may be separate, is coupled to the processor 1511. Alternatively, the memory 1512 may be integrated with the processor 1511, such as within a chip. The memory 1512 can store program codes for executing the technical solutions of the embodiments of the present application, and the processor 1511 controls execution of the program codes, and the executed computer program codes may also be regarded as drivers of the processor 1511. For example, the processor 1511 is configured to execute the computer program code stored in the memory 1512, so as to implement the technical solution in the embodiment of the present application.

The transceiver 1513 may be used to support the reception or transmission of radio frequency signals between the network device and the terminal, and the transceiver 1513 may be coupled to an antenna 1515. The transceiver 1513 includes a transmitter Tx and a receiver Rx. Specifically, one or more antennas 1515 may receive radio frequency signals, and the receiver Rx of the transceiver 1513 is configured to receive the radio frequency signals from the antennas, convert the radio frequency signals into digital baseband signals or digital intermediate frequency signals, and provide the digital baseband signals or digital intermediate frequency signals to the processor 1511, so that the processor 1511 performs further processing on the digital baseband signals or digital intermediate frequency signals, such as demodulation processing and decoding processing. In addition, the transmitter Tx in the transceiver 1513 is also used to receive a modulated digital baseband signal or a digital intermediate frequency signal from the processor 1511, convert the modulated digital baseband signal or the digital intermediate frequency signal into a radio frequency signal, and transmit the radio frequency signal through the one or more antennas 1515. Specifically, the receiver Rx may selectively perform one or more stages of down-mixing and analog-to-digital conversion processes on the rf signal to obtain a digital baseband signal or a digital intermediate frequency signal, wherein the order of the down-mixing and analog-to-digital conversion processes is adjustable. The transmitter Tx may selectively perform one or more stages of up-mixing and digital-to-analog conversion processes on the modulated digital baseband signal or the modulated digital intermediate frequency signal to obtain the rf signal, where the order of the up-mixing and the digital-to-analog conversion processes is adjustable. The digital baseband signal and the digital intermediate frequency signal may be collectively referred to as a digital signal.

Fig. 9 is a schematic structural diagram of a terminal device according to an embodiment of the present application. The structure of the first terminal may refer to the structure shown in fig. 9.

The terminal includes at least one processor 1611, at least one transceiver 1612, and at least one memory 1613. The processor 1611, memory 1613, and transceiver 1612 are connected. Optionally, the terminal can also include an output device 1614, an input device 1615, and one or more antennas 1616. The antenna 1616 is coupled to the transceiver 1612, and the output device 1614 and the input device 1615 are coupled to the processor 1611.

The transceiver 1612, memory 1613, and antenna 1616 may perform similar functions as described with respect to fig. 8.

The processor 1611 may be a baseband processor or a CPU, and the baseband processor and the CPU may be integrated together or separated.

The processor 1611 may be used to implement various functions for the terminal, such as processing communication protocols and communication data, or controlling the entire terminal device, executing software programs, and processing data of the software programs; or to assist in completing computational processing tasks, such as processing of graphical images or audio, etc.; or processor 1211 may be used to perform one or more of the functions described above

An output device 1614 is in communication with the processor 1611 and may display information in a variety of ways. For example, the output device 1214 may be a Liquid Crystal Display (LCD), a Light Emitting Diode (LED) Display device, a Cathode Ray Tube (CRT) Display device, a projector (projector), or the like. The input device 1615 is in communication with the processor 1611 and may accept user input in a variety of ways. For example, the input device 1615 may be a mouse, a keyboard, a touch screen device, a sensing device, or the like.

Fig. 10 is a schematic structural diagram of a communication device 1200 according to an embodiment of the present disclosure.

The communication apparatus 1200 includes a processing unit 1201 and a communication unit 1202. Optionally, the communication device 1200 further comprises a storage unit 1203. The processing unit 1201, the communication unit 1202, and the storage unit 1203 are connected by a communication bus.

The communication unit 1202 may be a device having a transceiving function for communicating with other network apparatuses or terminals.

The storage unit 1203 may include one or more memories.

The storage unit 1203 may be independent and connected to the processing unit 1201 through a communication bus. The storage unit 1203 may also be integrated with the processing unit 1201.

The communications apparatus 1200 may be used in a communications device, circuit, hardware component, or chip.

The communication apparatus 1200 may be a source base station or a target base station in the embodiment of the present application. A schematic diagram of a source base station or a target base station may be as shown in fig. 8. Alternatively, the communication unit 1202 of the communication apparatus 1200 may include an antenna and a transceiver of a network device, such as the antenna 1515 and the transceiver 1513 in fig. 8. The communication unit 1202 may also include a network interface of a network device, such as network interface 1514 in fig. 8.

The communication apparatus 1200 may be a chip in the source base station or a chip in the target base station in the embodiment of the present application. The communication unit 1202 may be an input or output interface, pin or circuit, or the like. Alternatively, the storage unit 1203 may store computer-executable instructions of the method on the network device side to cause the processing unit 1201 to execute the method on the network device side in the above-described embodiment. The storage unit 1203 may be a register, a cache, a RAM, or the like, and the storage unit 1203 may be integrated with the processing unit 1201; the storage unit 1203 may be a ROM or other type of static storage device that may store static information and instructions, and the storage unit 1203 may be separate from the processing unit 1201. Alternatively, as wireless communication technology evolves, a transceiver may be integrated on the communication device 1200, e.g., the communication unit 1202 integrates the transceiver 1513 and the network interface 1514.

The communication apparatus 1200 may be a first terminal in the embodiment of the present application. Alternatively, the communication unit 1202 of the communication apparatus 1200 may include an antenna and a transceiver of a terminal, such as the antenna 1616 and the transceiver 1612 in fig. 9. Optionally, the communication unit 1202 may also include output devices and input devices, such as output device 1614 and input device 1615 in fig. 9.

The communication apparatus 1200 may be a chip in the first terminal in the embodiment of the present application. The communication unit 1202 may be an input or output interface, pin or circuit, or the like. Alternatively, the storage unit 1203 may store computer-executable instructions of the method on the terminal side to cause the processing unit 1201 to execute the method of the first terminal in the above-described embodiment. The storage unit 1203 may be a register, a cache, a RAM, or the like, and the storage unit 1203 may be integrated with the processing unit 1201; the storage unit 1203 may be a ROM or other type of static storage device that may store static information and instructions, and the storage unit 1203 may be separate from the processing unit 1201. Optionally, as wireless communication technology advances, a transceiver may be integrated on the communication device 1200, for example, the communication unit 1202 integrates the transceiver 1212.

When the communication apparatus 1200 is a target base station or a chip in the target base station, the processing unit 1201 may perform actions handled by the target base station in the above method, the storage unit 1203 may perform actions stored in the above method, and the communication unit 1202 may perform actions interacting with the source base station or the first terminal in the above method, which is described as an example below:

the communication unit 1202 may receive first information from a source base station, where the first information includes one or more of measurement result information of a downlink between a first terminal and a target base station and location information of the first terminal, and the first information is used to determine a first timing advance, where the first timing advance is a timing advance for uplink transmission between the first terminal and the target base station; communication unit 1202 may transmit information of the first timing advance to the first terminal.

Optionally, the processing unit 1203 may determine a distance between the first terminal and the target base station according to the first information; and determining a first timing advance according to the distance between the first terminal and the target base station.

Optionally, when the first information includes measurement result information, the processing unit 1203 may determine, according to the measurement result information, a path loss between the target base station and the first terminal; and determining the distance between the first terminal and the target base station according to the path loss.

Alternatively, the processing unit 1203 may obtain the mapping relationship, the content of the mapping relationship may refer to the content in other embodiments, and the processing unit 1203 determines the first timing advance according to the mapping relationship and the first information.

Optionally, the communication unit 1202 may receive an RRC reconfiguration complete message from the first terminal, the RRC reconfiguration complete message being transmitted based on the first timing advance.

Optionally, the first information is further used to determine an initial transmission power of uplink transmission between the first terminal and the target base station, and the communication unit 1202 may send the information of the initial transmission power to the first terminal through the source base station.

When the communication apparatus 1200 is a first terminal or a chip in the first terminal, the processing unit 1201 may complete an action processed by the first terminal in the above method, the storage unit 1203 may complete an action stored by the first terminal in the above method, and the communication unit 1202 may complete an action interacting with the source base station or the target base station in the above method, which is described as follows:

the communication unit 1202 may receive, from the target base station through the source base station, a timing advance for uplink transmission between the first terminal and the target base station, where the timing advance is determined according to first information including one or more of measurement result information of a downlink between the first terminal and the target base station and location information of the first terminal.

Optionally, the communication unit 1202 may send an RRC reconfiguration complete message to the target base station, the RRC reconfiguration complete message being transmitted based on the timing advance.

Optionally, if the RRC reconfiguration complete message fails to be sent, the processing unit 1201 may initiate a random access procedure to the target base station.

Alternatively, the communication unit 1202 may receive, from the target base station through the source base station, information of an initial transmission power of uplink transmission between the first terminal and the target base station, where the initial transmission power is determined according to the first information.

When the communication apparatus 1200 is a source base station or a chip in the source base station, the processing unit 1201 may perform actions processed by the source base station in the above method, the storage unit 1203 may perform actions stored in the above method, and the communication unit 1202 may perform actions interacting with a target base station or a first terminal in the above method, which is described as an example below:

the communication unit 1202 may send, to the target base station, first information, where the first information is used to determine a timing advance for uplink transmission between the first terminal and the target base station, and the first information includes one or more of measurement result information of a downlink between the first terminal and the target base station and location information of the first terminal; the communication unit 1202 may receive information of timing advance from the target base station; the communication unit may transmit the timing advance information to the first terminal.

Optionally, the communication unit 1202 may receive, from the target base station, information of an initial transmission power of uplink transmission between the first terminal and the target base station, where the initial transmission power is determined according to the first information; the communication unit 1202 may transmit information of the initial transmission power to the first terminal.

Fig. 11 is a schematic block diagram of a network device 1700 according to an embodiment of the present application. As shown in fig. 11, the network device 1700 includes:

a receiving unit 1710, configured to receive first information from a source base station, where the first information includes one or more of measurement result information of a downlink between a first terminal and a network device 1700 and location information of the first terminal, and the first information is used to determine a first timing advance, where the first timing advance is a timing advance for uplink transmission between the first terminal and the network device 1700;

a transmitting unit 1720, configured to transmit the information of the first timing advance to the first terminal.

Optionally, the network device 1700 further comprises a determining unit 1730 for:

determining a distance between the first terminal and the network device 1700 according to the first information; the first timing advance is determined according to a distance between the first terminal and the network device 1700.

Optionally, when the first information includes measurement result information, the determining unit 1730 is further configured to determine a path loss between the network device 1700 and the first terminal according to the measurement result information; the distance between the first terminal and the network device 1700 is determined according to the path loss.

Optionally, the determining unit 1730 may be configured to obtain a mapping relationship, the content of the mapping relationship may refer to the content in other embodiments, and the determining unit 1730 is configured to determine the first timing advance according to the mapping relationship and the first information.

Optionally, the receiving unit 1710 is further configured to receive, from the first terminal, an RRC reconfiguration complete message, where the RRC reconfiguration complete message is transmitted based on the first timing advance.

Optionally, the first information is further used to determine an initial transmission power of uplink transmission between the first terminal and the network device 1700, and the sending unit 1720 is further used to send the information of the initial transmission power to the first terminal through the source base station.

Each unit and the other operations or functions in the network device 1700 in the embodiment of the present application are respectively for implementing the corresponding processes executed by the target base station in the embodiments described above. For brevity, no further description is provided herein.

Fig. 12 is a schematic block diagram of a terminal device 1800 according to an embodiment of the present application. As shown in fig. 12, the terminal device 1800 includes a receiving unit 1810 for:

receiving, by the source base station, a timing advance for uplink transmission between the terminal device 1800 and the target base station from the target base station;

wherein the timing advance is determined according to first information, the first information comprising one or more of measurement result information of a downlink between the terminal device 1800 and the target base station and location information of the first terminal.

Optionally, the measurement result information includes information of received power of the reference signal.

Optionally, the information of the timing advance is carried in the handover confirmation message and the handover command message.

Optionally, the terminal device 1800 further includes a sending unit 1820, configured to send an RRC reconfiguration complete message to the target base station, where the RRC reconfiguration complete message is transmitted based on the timing advance.

Optionally, if the RRC reconfiguration complete message is failed to be sent, the sending unit 1820 is further configured to initiate random access to the target base station.

Optionally, the receiving unit 1810 is further configured to receive, by the source base station, information of an initial transmission power of uplink transmission between the terminal device 1800 and the target base station from the target base station, where the initial transmission power is determined according to the first information.

The units and other operations or functions in the terminal device 1800 in the embodiment of the present application are respectively for implementing the corresponding flows executed by the first terminal in the embodiments described above. For brevity, no further description is provided herein.

Fig. 13 is a schematic block diagram of a network device 1900 according to an embodiment of the present application. As shown in fig. 13, the network device 1900 includes:

a sending unit 1910, configured to send first information to a target base station, where the first information is used to determine a timing advance for uplink transmission between a first terminal and the target base station, and the first information includes one or more of measurement result information of a downlink between the first terminal and the target base station and location information of the first terminal;

a receiving unit 1920, configured to receive the timing advance information from the target base station;

the transmitting unit 1910 is further configured to transmit the timing advance information to the first terminal.

Optionally, the receiving unit 1920 is further configured to receive, from the target base station, information of an initial transmission power of uplink transmission between the first terminal and the target base station, where the initial transmission power is determined according to the first information;

the transmitting unit 1910 is further configured to transmit information of initial transmission power to the first terminal.

Each unit and the other operations or functions in the network device 1900 of the embodiment of the present application are respectively for implementing the corresponding flow executed by the source base station in each embodiment described above. For brevity, no further description is provided herein.

Processors in the present application may include, but are not limited to, at least one of: various computing devices that run software, such as a Central Processing Unit (CPU), a microprocessor, a Digital Signal Processor (DSP), a Microcontroller (MCU), or an artificial intelligence processor, may each include one or more cores for executing software instructions to perform operations or processing. The processor may be a single semiconductor chip or integrated with other circuits to form a semiconductor chip, for example, an SoC (system on chip) with other circuits (such as a codec circuit, a hardware acceleration circuit, or various buses and interface circuits), or may be integrated in the ASIC as a built-in processor of the ASIC, which may be packaged separately or together with other circuits. The processor may further include necessary hardware accelerators such as Field Programmable Gate Arrays (FPGAs), PLDs (programmable logic devices), or logic circuits implementing dedicated logic operations, in addition to cores for executing software instructions to perform operations or processes.

In implementation, the steps of the above method may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The steps of a method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in a processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor. To avoid repetition, it is not described in detail here.

It should be noted that the processor in the embodiments of the present application may be an integrated circuit chip having signal processing capability. In implementation, the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The processor described above may be a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components. The various methods, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

The memory in the embodiments of the present application may be either volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The non-volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable Programmable ROM (EPROM), an Electrically Erasable Programmable ROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), double data rate SDRAM (ddr SDRAM), Enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

According to the method provided by the embodiment of the present application, the present application further provides a computer program product, which includes: computer program code which, when run on a computer, causes the computer to perform the method of any of the embodiments shown in figures 2-6.

According to the method provided by the embodiment of the present application, the present application further provides a computer-readable medium, which stores program codes, and when the program codes are executed on a computer, the computer is caused to execute the method of any one of the embodiments shown in fig. 2 to 6.

According to the method provided by the embodiment of the present application, the present application further provides a system, which includes the foregoing one or more terminal devices and one or more network devices.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a Digital Video Disk (DVD)), or a semiconductor medium (e.g., a Solid State Disk (SSD)), among others.

The network device in the foregoing device embodiments completely corresponds to the terminal device and the network device or the terminal device in the method embodiments, and the corresponding module or unit executes the corresponding steps, for example, the communication unit (transceiver) executes the steps of receiving or transmitting in the method embodiments, and other steps besides transmitting and receiving may be executed by the processing unit (processor). The functions of the specific elements may be referred to in the respective method embodiments. The number of the processors may be one or more.

As used in this specification, the terms "component," "module," "system," and the like are intended to refer to a computer-related entity, either hardware, firmware, a combination of hardware and software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component may be localized on one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components may communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from two components interacting with another component in a local system, distributed system, and/or across a network such as the internet with other systems by way of the signal).

Those of ordinary skill in the art will appreciate that the various illustrative logical blocks and steps (step) described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

In the present application, "at least one" means one or more. "plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone, wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple. In addition, in order to facilitate clear description of technical solutions of the embodiments of the present application, in the embodiments of the present application, terms such as "first" and "second" are used to distinguish the same items or similar items having substantially the same functions and actions. Those skilled in the art will appreciate that the terms "first," "second," etc. do not denote any order or quantity, nor do the terms "first," "second," etc. denote any order or importance.

In the present application, the first and second are used for distinguishing purposes only and are not limited, and the first and second may be interchanged.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of communication, the method comprising:

receiving first information from a source base station, wherein the first information comprises one or more of measurement result information of a downlink between a first terminal and a target base station and position information of the first terminal, and the first information is used for determining a first timing advance, and the first timing advance is timing advance of uplink transmission between the first terminal and the target base station;

and sending the information of the first timing advance to the first terminal through the source base station.

2. The method of claim 1, further comprising:

determining the distance between the first terminal and the target base station according to the first information;

and determining the first timing advance according to the distance between the first terminal and the target base station.

3. The method of claim 2, wherein when the first information comprises the measurement result information, the determining the distance between the first terminal and the target base station according to the first information comprises:

determining the path loss between the target base station and the first terminal according to the measurement result information;

and determining the distance between the first terminal and the target base station according to the path loss.

4. The method of claim 1, further comprising:

acquiring a mapping relation, wherein the mapping relation is a mapping relation between second information and a second timing advance, the second information includes one or more of measurement result information of a downlink between a second terminal and the target base station and position information of the second terminal, and the second timing advance is a timing advance of uplink transmission between the second terminal and the target base station;

and determining the first timing advance according to the mapping relation and the first information.

5. The method according to any of claims 1-4, wherein the measurement result information comprises information of received power of a reference signal.

6. The method according to any of claims 1-5, wherein the first information is carried in a handover request message and the information of the first timing advance is carried in a handover confirm message and a handover command message.

7. The method according to any one of claims 1-6, further comprising:

receiving a radio resource control, RRC, reconfiguration complete message from the first terminal, the RRC reconfiguration complete message transmitted based on the first timing advance.

8. The method according to any of claims 1-7, wherein the first information is further used for determining an initial transmit power for uplink transmission between the first terminal and the target base station; the method further comprises the following steps:

and sending the information of the initial transmitting power to the first terminal through the source base station.

9. A method of communication, the method comprising:

receiving a timing advance of uplink transmission between a first terminal and a target base station from the target base station through a source base station;

wherein the timing advance is determined according to first information, the first information including one or more of measurement result information of a downlink between the first terminal and the target base station and location information of the first terminal.

10. The method of claim 9, wherein the measurement result information comprises information of received power of a reference signal.

11. The method of claim 9 or 10, wherein the timing advance information is carried in a handover confirm message and a handover command message.

12. The method according to any one of claims 9-11, further comprising:

sending an RRC reconfiguration complete message to the target base station, the RRC reconfiguration complete message being transmitted based on the timing advance.

13. The method of claim 12, wherein if the RRC reconfiguration complete message transmission fails, the method further comprises:

and initiating random access to the target base station.

14. The method according to any one of claims 9-13, further comprising:

receiving, by the source base station, information of initial transmission power of uplink transmission between the first terminal and the target base station from the target base station, where the initial transmission power is determined according to the first information.

15. A method of communication, the method comprising:

sending first information to a target base station, wherein the first information is used for determining a timing advance of uplink transmission between a first terminal and the target base station, and the first information comprises one or more of measurement result information of downlink between the first terminal and the target base station and position information of the first terminal;

receiving information of the timing advance from the target base station;

and sending the information of the timing advance to the first terminal.

16. The method of claim 15, wherein the measurement result information comprises information of received power of a reference signal.

17. The method of claim 15 or 16, wherein the first information is carried in a handover request message, and wherein the information of the timing advance is carried in a handover confirm message and a handover command message.

18. The method according to any one of claims 15-17, further comprising:

receiving information of initial transmitting power of uplink transmission between the first terminal and the target base station from the target base station, wherein the initial transmitting power is determined according to the first information;

and sending the information of the initial transmitting power to the first terminal.

19. A communications apparatus comprising a processor coupled to a memory, the memory storing a computer program or instructions, the processor being configured to execute the computer program or instructions such that the method of any of claims 1 to 8 or the method of any of claims 9 to 14 or the method of any of claims 15 to 18 is performed.

20. A chip comprising a processor and interface circuitry, the interface circuitry being coupled to the processor, the processor being configured to execute a computer program or instructions to cause the method of any of claims 1 to 8 or the method of any of claims 9 to 14 or the method of any of claims 15 to 18 to be performed, the interface circuitry being configured to communicate with a module other than the chip.