CN117119540A

CN117119540A - Satellite switching method and device

Info

Publication number: CN117119540A
Application number: CN202210529415.2A
Authority: CN
Inventors: 毛健鹏; 韩小江; 杜颖钢
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-05-16
Filing date: 2022-05-16
Publication date: 2023-11-24

Abstract

The application provides a satellite switching method and device. The satellite switching method provided by the application comprises the following steps: the first satellite first acquires first information for indicating the moment when the beam of the second satellite scans to the position of the user equipment UE; determining a second time for transmitting a handover command to the UE based on the first information and a latest time at which the handover command is received by the UE; and sending the switching command to the UE at the second moment. According to the satellite switching method provided by the application, the time delay of switching the UE from the first satellite to the second satellite can be reduced.

Description

Satellite switching method and device

Technical Field

The present application relates to the field of communications technologies, and in particular, to a satellite switching method and apparatus.

Background

With the development of communication technology, more urgent demands are placed on the efficiency, mobility, diversity, and the like of communication. Currently, one development in the field of communication systems focuses on global mobile communications, and an important component of global mobile communications is satellite communications. The satellite communication has the characteristics of long communication distance, large coverage area, flexible networking and the like, and can provide services for fixed terminals and various mobile terminals.

In a satellite communication scene, the cell range covered by a single satellite can reach hundreds of thousands of square kilometers, but the whole area is covered, hundreds of satellites are still required to be covered in a networking way, and due to the high-speed movement of the satellites, a User Equipment (UE) in a connection state still needs to be frequently switched among different satellites so as to ensure the continuity of services.

Specifically, the handover procedure of the UE between different satellites is as follows: the UE reports at least one measurement report to the source satellite, wherein the at least one measurement report corresponds to the at least one satellite, and each measurement report indicates the signal quality of a detection signal sent by the corresponding satellite; after receiving at least one measurement report, the source satellite judges a target satellite to which the UE needs to be switched according to a preset switching judgment algorithm, and then the source satellite sends a switching request (handover request) message to the target satellite so as to request the target satellite to allocate resources for the UE; after receiving the switching request message, the target satellite allocates resources for the UE if the UE is allowed to switch, and sends a switching request acknowledgement (handover request acknowledge) message to the source satellite, and the switching process is prepared to be successful; and after receiving the switching request confirmation message, the source satellite sends a switching command to the UE to instruct the UE to switch to the target satellite, and the UE suspends uplink and downlink services and accesses the target satellite side according to the information of the switching command.

However, the above-mentioned handover procedure results in a larger handover delay when the UE performs handover between different satellites. Therefore, how to reduce the switching delay when the UE switches between different satellites becomes a technical problem to be solved.

Disclosure of Invention

The application provides a satellite switching method and device, which can reduce switching time delay when UE switches between different satellites.

In a first aspect, the present application provides a satellite switching method, applied to a first satellite, including: acquiring first information, wherein the first information is used for indicating the moment when a beam of a second satellite is scanned to the position of User Equipment (UE), and the second satellite is a satellite which needs to be switched by the UE; determining a second time for transmitting a switching command to the UE based on the first information and the first time, wherein the switching command indicates the UE to access to the second satellite, and the first time is the latest time when the UE receives the switching command; and sending the switching command to the UE at the second moment.

In this embodiment, after the first satellite obtains the handover request acknowledgement message, the first satellite calculates the time when the handover command is issued to the UE, and then issues the handover command to the UE at the calculated issue time. In the application, the time of issuing the switching command to the UE is controlled to ensure that the UE communicates with the first satellite before issuing the switching command, so that the time for suspending uplink and downlink business of the UE is reduced, and the switching time delay is reduced.

With reference to the first aspect, in a possible implementation manner, the acquiring the first information includes: transmitting second information to the second satellite, the second information indicating location information of the UE; receiving the first information sent by the second satellite, wherein the first information is determined by the second satellite based on the following information: ephemeris information of the second satellite, beam scanning rule information of the second satellite, and location information of the UE.

In this implementation manner, in order to obtain the time when the beam of the second satellite scans to the position of the UE, the first satellite may first send the position information of the UE to the second satellite, and then the second satellite determines the time when the beam of the second satellite scans to the position of the UE based on the position information of the UE, ephemeris information of the second satellite, and beam scanning rule information of the second satellite. That is, in this implementation, a time at which a beam of the second satellite scans to a location of the UE may be determined based on the second satellite, and then the second satellite transmits the determined time to the first satellite.

With reference to the first aspect, in one possible implementation manner, the second information is carried in a handover request message, where the handover request message is used by the first satellite to request, from the second satellite, that the UE needs to be handed over to the second satellite.

In this implementation manner, when the second satellite determines that the beam of the second satellite scans the position of the UE, the first satellite carries the position information of the UE in the handover request message, so that the second satellite can obtain the position information of the UE from the handover request message, and further, the second satellite can determine the time when the beam of the second satellite scans the position of the UE based on the position information of the UE, ephemeris information of the second satellite, and beam scanning rule information of the second satellite.

With reference to the first aspect, in one possible implementation manner, the first information is carried in a handover request acknowledgement message, where the handover request acknowledgement message indicates that the second device allows the UE to handover from the first satellite to the second satellite.

In this implementation manner, when the second satellite determines that the second satellite scans the beam to the position of the UE, the determined time may be carried in the handover request acknowledgement message, so as to implement that the first satellite may obtain, from the handover request acknowledgement message, time information of the second satellite that the beam scans to the position of the UE.

With reference to the first aspect, in a possible implementation manner, the acquiring the first information includes: acquiring ephemeris information of the second satellite and beam scanning rule information of the second satellite; the first information is determined based on the location information of the UE, ephemeris information of the second satellite, and beam scanning rule information of the second satellite.

With reference to the first aspect, in a possible implementation manner, the acquiring ephemeris information of the second satellite and beam scanning rule information of the second satellite includes: and receiving the ephemeris information of the second satellite and the beam scanning rule information of the second satellite, which are sent by the second satellite.

With reference to the first aspect, in one possible implementation manner, ephemeris information of the second satellite and beam scanning rule information of the second satellite are preset in the first satellite.

With reference to the first aspect, in a possible implementation manner, the method further includes: receiving at least one measurement report sent by the UE, wherein the at least one measurement report corresponds to at least one satellite one by one, and each measurement report indicates the signal quality of a detection signal sent by the corresponding satellite; the second satellite is determined from the at least one satellite based on the at least one measurement report.

In a second aspect, the present application provides a satellite switching method, applied to a second satellite, including: acquiring second information sent by a first satellite, wherein the second information indicates the position information of User Equipment (UE) which needs to be switched from the first satellite to the second satellite; determining first information indicating a time when a beam of the second satellite is scanned to a position of the UE based on ephemeris information of the second satellite, beam scanning rule information of the second satellite, and position information of the UE; the first information is transmitted to the first satellite.

With reference to the second aspect, in one possible implementation manner, the first information is carried in a handover request acknowledgement message, where the handover request acknowledgement message indicates that the second device allows the UE to handover from the first satellite to the second satellite.

In a third aspect, the present application provides a satellite switching device, applied to a first satellite, including: the receiving and transmitting module is used for acquiring first information, wherein the first information is used for indicating the moment when a beam of a second satellite is scanned to the position of User Equipment (UE), and the second satellite is a satellite which needs to be switched by the UE; the processing module is used for determining a second moment for sending a switching command to the UE based on the first information and the first moment, the switching command indicates the UE to access to the second satellite, and the first moment is the latest moment when the UE receives the switching command; the transceiver module is further configured to send the handover command to the UE at the second time.

With reference to the third aspect, in one possible implementation manner, the transceiver module is further configured to: transmitting second information to the second satellite, the second information indicating location information of the UE; receiving the first information sent by the second satellite, wherein the first information is determined by the second satellite based on the following information: ephemeris information of the second satellite, beam scanning rule information of the second satellite, and location information of the UE.

With reference to the third aspect, in one possible implementation manner, the second information is carried in a handover request message, where the handover request message is used by the first satellite to request, from the second satellite, that the UE needs to be handed over to the second satellite.

With reference to the third aspect, in a possible implementation manner, the first information is carried in a handover request acknowledgement message, where the handover request acknowledgement message indicates that the second device allows the UE to handover from the first satellite to the second satellite.

With reference to the third aspect, in one possible implementation manner, the transceiver module is further configured to: acquiring ephemeris information of the second satellite and beam scanning rule information of the second satellite; the processing module is further configured to: the first information is determined based on the location information of the UE, ephemeris information of the second satellite, and beam scanning rule information of the second satellite.

With reference to the third aspect, in one possible implementation manner, the transceiver module is further configured to: and receiving the ephemeris information of the second satellite and the beam scanning rule information of the second satellite, which are sent by the second satellite.

With reference to the third aspect, in one possible implementation manner, ephemeris information of the second satellite and beam scanning rule information of the second satellite are preset in the first satellite.

With reference to the third aspect, in one possible implementation manner, the transceiver module is further configured to: receiving at least one measurement report sent by the UE, wherein the at least one measurement report corresponds to at least one satellite one by one, and each measurement report indicates the signal quality of a detection signal sent by the corresponding satellite; the processing module is further configured to: the second satellite is determined from the at least one satellite based on the at least one measurement report.

In a fourth aspect, the present application provides a satellite switching device, applied to a second satellite, including: the receiving and transmitting module is used for acquiring second information sent by a first satellite, wherein the second information indicates the position information of User Equipment (UE) which needs to be switched from the first satellite to the second satellite; a processing module configured to determine first information indicating a time at which a beam of the second satellite is scanned to a position of the UE based on ephemeris information of the second satellite, beam scanning rule information of the second satellite, and position information of the UE; the transceiver module is further configured to: the first information is transmitted to the first satellite.

With reference to the fourth aspect, in a possible implementation manner, the first information is carried in a handover request acknowledgement message, where the handover request acknowledgement message indicates that the second device allows the UE to handover from the first satellite to the second satellite.

In a fifth aspect, the present application provides a computer readable medium storing program code for computer execution, the program code comprising instructions for performing the method of the first aspect or the second aspect or any one thereof.

In a sixth aspect, the present application provides a computer program product comprising computer program code embodied therein, which when run on a computer causes the computer to carry out the method according to the first aspect or the second aspect or any one thereof.

Drawings

Fig. 1 is a schematic structural diagram of a satellite communication scenario provided by the present application;

fig. 2 is a schematic diagram of a handover of a terminal device caused by satellite movement provided in the present application;

fig. 3 is a schematic diagram of a network architecture of a satellite communication system according to the present application;

FIG. 4 is a schematic flow chart of a method for satellite switching according to an embodiment of the application;

FIG. 5 is a schematic flow chart of a method for satellite switching according to an embodiment of the application;

FIG. 6 is a schematic flow chart of a method for satellite switching according to an embodiment of the application;

FIG. 7 is a schematic block diagram illustrating an apparatus for satellite switching according to an embodiment of the present application;

Fig. 8 is a schematic structural diagram of a satellite switching device according to an embodiment of the application.

Detailed Description

The technical scheme of the application will be described below with reference to the accompanying drawings.

The embodiments of the present application may be applied to various communication systems, such as a wireless local area network system (wireless local area network, WLAN), a narrowband internet of things system (NB-internet of things), a global system for mobile communications (GSM) evolution system (enhanced data rate for GSM evolution, EDGE), a wideband code division multiple access system (wideband code division multiple access, WCDMA), a code division multiple access 2000 system (code division multiple access, CDMA 2000), a time division synchronous code division multiple access system (time division-synchronization code division multiple access, TD-SCDMA), a long term evolution system (long term evolution, LTE), satellite communications, a fifth generation (5th generation,5G) system, or new communication systems that are emerging in the future, etc.

Fig. 1 is a schematic structural diagram of a satellite communication scenario provided by the present application. As shown in fig. 1, a terminal device 101 and a satellite 102 are included in this scenario. Wherein the terminal device 101 may communicate with the satellite 102 when the terminal device 101 is located in a cell covered by the satellite 102.

The terminal device 101 according to the embodiment of the present application may include various handheld devices, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem. The terminal may be a Mobile Station (MS), a subscriber unit (subscriber unit), a User Equipment (UE), a cellular phone (cellular phone), a smart phone (smart phone), a wireless data card, a personal digital assistant (personal digital assistant, PDA) computer, a tablet computer, a wireless modem (modem), a handheld device (handset), a laptop computer (laptop computer), a machine type communication (machine type communication, MTC) terminal, etc.

In the satellite communication scene, the cell range covered by a single satellite can reach hundreds of thousands square kilometers, but hundreds of thousands of satellites are still required to be covered in a networking way to cover the whole area.

In addition, due to the high-speed movement of satellites, a User Equipment (UE) in a connected state still needs to be frequently switched between different satellites to ensure the continuity of services.

For ease of understanding, fig. 2 is a schematic diagram of a handoff of a terminal device caused by satellite movement. As shown in fig. 2, due to the movement of the satellite, the satellite 202 covers the location of the terminal device 201 at time 1, the satellite 202 moves to other places, the satellite 203 covers the location of the terminal device 201 at time 2, the satellite 203 moves to other places, and the satellite 204 covers the location of the terminal device 201 at time 3, so that the terminal device 201 is provided with access services by different satellites at different times, and in the process, the terminal device 201 is to be handed over between different satellite cells.

The application belongs to the category of satellite communication, and each member of the third generation partnership project (3rd Generation Partnership Project,3GPP) fuses the satellite communication and the 5G technology and provides a typical network application architecture. Fig. 3 is a schematic diagram of a network architecture of the satellite communication system according to the present application. As shown in fig. 3, the ground mobile terminal UE accesses the network through a new air interface of 5G, and the 5G base station is deployed on a satellite and connected to a core network on the ground through a wireless link. Meanwhile, a wireless link exists between satellites, so that signaling interaction and user data transmission between base stations are completed. The individual network elements and their interfaces in fig. 3 are illustrated as follows:

And (3) a terminal: mobile devices supporting a new air interface of 5G, such as mobile phones and pad mobile devices, are typical. The satellite network can be accessed through an air interface, and the services such as calling, surfing the Internet and the like are initiated.

5G base station: mainly provides wireless access service, schedules wireless resources to access terminals, provides reliable wireless transmission protocols and data encryption protocols, etc.

5G core network: user access control, mobility management, session management, user security authentication, charging and other services. It is composed of several functional units, and can be divided into control plane and data plane functional entities. An access and mobility management unit (Accessand Mobility Management Function, AMF) is responsible for user access management, security authentication, and mobility management. The User Plane Unit (UPF) is responsible for managing functions of User Plane data transmission, traffic statistics, secure eavesdropping, etc. The session management unit (Session Management Function, SMF) is mainly responsible for interacting with the separate data plane.

Ground station: and is responsible for forwarding signaling and traffic data between the satellite base station and the 5G core network.

5G new air interface: wireless link between terminal and base station.

An Xn interface: the interface between the 5G base station and the base station is mainly used for signaling interaction such as switching.

NG interface: and an interface between the 5G base station and the 5G core network.

Before introducing the satellite switching method of the application, the whole flow of satellite switching is introduced. Specifically, the process includes:

step one: the UE receives a plurality of detection signals, wherein the detection signals are in one-to-one correspondence with a plurality of satellites, and the satellites corresponding to the detection signals are periodically transmitted in a broadcast mode.

For example, the detection signals may be synchronization signal block (synchronization signal block, SSB) signals, each SSB signal corresponding one-to-one to each satellite. Wherein the SSB signal includes a primary synchronization signal, a secondary synchronization signal, and a physical broadcast channel. It should be understood that when the beam scanning signal of the SSB is transmitted to the terminal device, the UE may acquire relevant parameters, such as master information block (master information block, MIB) information in the PBCH, including information such as a system frame number, a subcarrier spacing of the SSB, a subcarrier offset of the SSB, and an SSB index, from the SSB in the beam. It is noted that, the detailed description of the SSB may refer to the description in the related art, and will not be repeated here.

Step two: the UE transmits at least one measurement report to the first satellite, and accordingly, the first satellite receives the at least one measurement report, wherein the at least one measurement report corresponds to the at least one satellite one by one, and each measurement report indicates a signal quality of a detection signal transmitted by the corresponding satellite.

In this embodiment, the first satellite refers to a satellite that has established a communication connection with the UE. In the present application, the first satellite is also referred to as a source satellite, and does not limit the present application.

It is explained here that the present embodiment does not limit the specific implementation how the UE sends at least one measurement report to the first satellite, for example.

For example, in one possible implementation, the number of measurement reports sent by the UE to the first satellite is the same as the number of received plurality of detection signals. That is, the UE may transmit all received measurement reports to the first satellite.

For example, in another possible implementation, the UE may send only at least one measurement report meeting the preset condition to the first satellite.

Step three: the first satellite determines a second satellite from the at least one satellite based on the at least one measurement report.

The second satellite refers to a satellite that the UE needs to switch, or may also be considered as a satellite that the UE needs to access. In the present application, the second satellite is also referred to as a target satellite, and does not constitute a limitation of the present application. The concept of satellite handoff may refer to the relevant portions of the above embodiments of the present application or the description of the related art, and will not be repeated here.

Step four: the first satellite sends switching request information to the second satellite, and accordingly, the second satellite receives the switching request information, wherein the switching request information is used for requesting the second satellite that the UE needs to access the second satellite.

In this embodiment, when the first satellite determines that the UE needs to be handed over from the first satellite to the second satellite, the first satellite sends a handover request message to the second satellite, so as to indicate to the second satellite that the UE wants to establish a communication connection with the second satellite.

In this description, in the embodiment of the present application, specific information included in the handover request information is not limited. For example, identification information of the UE, SIB1 of the first satellite or measurement report information of the UE, and the like are included.

Step five: after receiving the handover request message, if the second satellite allows the UE to establish a connection with the second satellite, the second satellite sends handover request confirmation information to the first satellite, and correspondingly, the first satellite receives the handover request confirmation information.

In this embodiment, after receiving the handover request message, the second satellite may know that the UE wants to establish a connection with the second satellite, at this time, the second satellite may perform admission judgment, if the second satellite allows the UE to switch, it allocates a radio resource including a temporary identifier and the like to the UE, and sends handover request acknowledgement information to the target base station, so as to indicate to the first satellite that handover preparation is successful. The concept of admission judgment can refer to the description in the related art, and is not repeated here.

In the present application, the handover request information is also referred to as a handover request message, and the handover request acknowledgement information is also referred to as a handover request acknowledgement message.

Step six: and after receiving the switching request confirmation information, the first satellite sends a switching command to the UE so as to instruct the UE to access to the second satellite.

The switching command may carry resource information allocated to the UE by the second satellite, so that the UE may access to the second satellite.

Step seven: and according to the information of the switching command, performing network searching on the second satellite side, scanning system information and accessing to recover uplink and downlink services.

It is noted that, the detailed description of the first to seventh steps may refer to the description in the related art, and will not be repeated herein.

On the basis of the first to seventh steps, for the sixth step, as long as the first satellite receives the handover request acknowledgement message sent by the second satellite, a handover command is sent to the UE.

However, it should be understood that in satellite communication systems, each satellite requires 10 times (e.g., 200-600 beams) or more beams where it covers different cells by beam scanning, which increases the period of beam scanning by a factor of 10, due to the wide range of cells covered by a single satellite.

Therefore, for the above-mentioned handover procedure, the time for the beam of the second satellite to scan to the location of the cell where the UE is located is long due to the large number of beams of the second satellite and the long beam scanning period. Therefore, after the UE receives the handover command sent by the first satellite, the UE needs to wait until the beam of the target satellite scans the location of the cell where the UE is located, so that the UE in step seven is always in an empty scanning state, and the handover delay is large.

In view of this, the present application proposes a method for satellite handoff. Specifically, after the first satellite receives the switching request confirmation information, the first satellite reduces the time for the UE to wait for the beam of the second satellite to scan to the UE by controlling the time for the switching command to be issued to the UE, thereby reducing the time delay of switching the UE from the first satellite to the second satellite.

Specifically, fig. 4 is a method for satellite handoff according to an embodiment of the present application. As shown in fig. 4, the method of the present embodiment includes: s401, S402 and S403.

S401, a first satellite acquires first information, wherein the first information is used for indicating the moment when a beam of a second satellite scans to the position of User Equipment (UE), and the second satellite is a satellite which needs to be switched by the UE.

In this embodiment, the second satellite, i.e. the satellite that the UE needs to re-access, is also referred to as the target satellite. The description of the second satellite may also refer to the description of the above embodiments of the present application, and will not be repeated here.

In this embodiment, the first information acquired by the first satellite is information indicating the time at which the beam of the second satellite is scanned to the position of the user equipment UE.

In a first possible implementation manner, the first satellite may acquire the first information by: the first satellite sends second information to the second satellite, wherein the second information indicates the position information of the UE; accordingly, the second satellite receives the second information, and determines information of a moment (i.e., first information) when the beam of the second satellite scans to the position of the user equipment UE based on the position information of the UE, ephemeris information of the second satellite, and beam scanning rule information of the second satellite, and then the second satellite transmits the first information to the first satellite, so that the first satellite can know the moment when the beam of the second satellite scans to the position of the user equipment UE.

That is, in the first implementation, the information determining the moment at which the beam of the second satellite scans to the position of the user equipment UE is determined by the second satellite (target satellite).

In a second possible implementation manner, the first satellite may acquire the first information by: the method comprises the steps that a first satellite firstly acquires ephemeris information of a second satellite and beam scanning rule information of the second satellite; then, the first satellite determines information (i.e., first information) of a moment when the beam of the second satellite scans to the position of the user equipment UE based on the position information of the UE, ephemeris information of the second satellite, and beam scanning rule information of the second satellite.

That is, in a second implementation, the information determining the moment at which the beam of the second satellite scans to the location of the user equipment UE is determined by the first satellite (source satellite).

Specifically, optionally, in the second implementation manner, one implementation manner of acquiring ephemeris information of the second satellite and beam scanning rule information of the second satellite by the first satellite is: the second satellite transmits the ephemeris information of the second satellite and the beam scanning rule information of the second satellite to the first satellite, and accordingly, the first satellite receives the ephemeris information of the second satellite and the beam scanning rule information of the second satellite. Here, the present embodiment is not limited to the manner in which the second satellite transmits the ephemeris information of the second satellite and the beam scanning rule information of the second satellite, and for example, the second satellite may transmit in an event-triggered manner or periodically, or may transmit to the first satellite whenever the ephemeris information of the second satellite and the beam scanning rule information of the second satellite change.

Specifically, optionally, in the second implementation manner, another implementation manner of acquiring ephemeris information of the second satellite and beam scanning rule information of the second satellite by the first satellite is: the ephemeris information of a second satellite and the beam scanning rule information of the second satellite are preset in the first satellite.

It is described herein that the embodiment of the present application does not limit how the first satellite obtains the location information of the UE. For example, the first satellite may send location request information to the UE, where the location request information is used by the first satellite to request the UE for the location of the UE, and after receiving the location request information, the UE obtains current location information and then sends the location information to the first satellite. Alternatively, the UE may carry the location information in a measurement report, so that the first satellite may acquire the location information of the UE based on the measurement report.

It is also explained here that the present embodiment does not limit the implementation manner of how the first satellite/second satellite obtains information of the moment when the beam of the second satellite scans to the position of the user equipment UE based on the position information of the UE, the ephemeris information of the second satellite, and the beam scanning rule information of the second satellite.

For example, in one possible implementation, assuming that the second satellite includes a total of M beams and performs beam scanning in a column, the second satellite may know the time (called the first time) of the beam currently being scanned (called the first beam), and then, after determining the location of the UE, may determine the beam that can be scanned to the UE (called the target beam) based on the location of the UE and ephemeris information of the second satellite. For example, assuming 500 scan beams, numbered from 0 to 499, respectively, numbered 500, the various angles may be determined by performing some calculations based on the position of the UE and ephemeris information of the second satellite, and finally determining which of the 500 beams will be directed to the position of the UE, e.g., calculating that the 300 th beam can be swept to the UE. After that, when the target beam is determined, the moment when the target beam scans the UE can be continuously determined based on the beam scanning rule information and the first time. For example, the number of the current first beam is 280, the number of the target beam is 300, the middle of the number is different by 20 beams, and since each beam has time to scan, for example, one millisecond or two milliseconds between the scanning of the next beam, the time difference from the first beam to the target beam can be determined, and finally, the moment when the beam of the second satellite scans the position of the user equipment UE can be obtained based on the first time and the time difference.

And S402, the first satellite determines a second moment for sending a switching command to the UE based on the first information and the first moment, wherein the switching command indicates the UE to access to the second satellite, and the first moment is the latest moment when the UE receives the switching command.

In this embodiment, the first time is the latest time when the UE receives the handover command, and the concept of the handover command may refer to the description in the foregoing embodiment or related technology of the present application, which is not repeated herein.

It will be appreciated that it is time-limited for the first satellite to send a handover command to the UE. For example, when the first satellite is far away from the UE so that it cannot cover the cell where the UE is located, the first satellite and the UE may not be able to establish communication any more, so that the first satellite cannot issue a handover command to the UE to instruct the UE to handover to the second satellite.

It will be appreciated that the first satellite, after having determined the latest instant and the instant (first information) at which the beam of the second satellite is scanned to the position of the user equipment UE, can control the second instant of the handover command based on both instants.

For example, in a specific implementation, one possible implementation of controlling the second time of the handover command based on these two times is: the first satellite determines the current time at which the handoff request acknowledge message sent by the second satellite was received, and then starts a timer based on the current time. For example, assuming that the current time is 10 minutes and the time of the UE scanned by the second satellite is 10 minutes, a timer is started at this time, for example, the timer is triggered at 10 minutes and 9 minutes, and then a handover command is issued to the UE.

S403, the first satellite sends a switching command to the UE at the second moment, and accordingly, the UE receives the switching command.

In this embodiment, after determining the time to send the handover command to the UE, the first satellite sends the handover command to the UE at that time.

It can be appreciated that in this embodiment, since the first satellite calculates the time when the handover command is issued to the UE after obtaining the handover request acknowledgement message, then issues the handover command to the UE at the calculated issue time. In the application, the time of issuing the switching command to the UE is controlled to ensure that the UE communicates with the first satellite before issuing the switching command, so that the time for suspending uplink and downlink business of the UE is reduced, and the switching time delay is reduced.

In the following, two specific embodiments of the handover method in satellite communications provided by the present application are described for ease of understanding.

In a first possible embodiment, as shown in fig. 5, a handover method for satellite communication includes:

s501, when a first satellite determines that User Equipment (UE) needs to be switched from the first satellite to a second satellite, sending switching request information to the second satellite, wherein the switching request information is used for requesting the second satellite that the UE needs to be accessed to the second satellite, and the switching request information carries the position information of the UE; accordingly, the second satellite receives the handover request information.

In this embodiment, after determining that the UE needs to be handed over from the first satellite to the second satellite, the first device further carries the location information of the UE in the handover request information when sending the handover request message to the second satellite. Accordingly, after receiving the handover request information sent by the first satellite, the second satellite may obtain the location information of the UE that needs to be handed over to the second satellite from the handover request information.

S502, the second satellite determines the moment when the beam of the second satellite scans to the position of the UE based on the position information of the UE, the ephemeris information of the second satellite and the beam scanning rule information of the second satellite.

In this embodiment, based on the location information of the UE, the ephemeris information of the second satellite, and the beam scanning rule information of the second satellite, determining the time when the beam of the second satellite is scanned to the location of the UE is implemented by the second satellite. The determining the time when the beam of the second satellite scans the position of the UE based on the position information of the UE, the ephemeris information of the second satellite, and the beam scanning rule information of the second satellite may be referred to the description in the embodiment shown in fig. 4, which is not repeated herein.

S503, the second satellite sends a switching request confirmation message to the first satellite, wherein the switching request confirmation message carries first information, and the first information indicates the time when the beam of the second satellite scans to the position of the UE; accordingly, the first satellite receives the handoff request acknowledge message.

In this embodiment, the time information of scanning the beam of the second satellite to the position of the UE, which is determined by the second device, is carried in the handover request acknowledgement message, so that the first satellite can obtain the time of scanning the beam of the second satellite to the position of the UE from the handover request acknowledgement message.

And S504, the first satellite determines a second moment for sending a switching command to the UE based on the first information and the first moment, wherein the switching command indicates the UE to access to the second satellite, and the first moment is the latest moment for sending the switching command by the first satellite.

The description in S402 in the embodiment shown in fig. 4 may be referred to for this portion, and will not be repeated here.

S505, the first satellite sends a handover command at the second moment, and accordingly, the UE receives the handover command.

In this embodiment, the first satellite sends the obtained position information of the UE to the second satellite, so that the second satellite determines, based on the position information of the UE, ephemeris information of the second satellite, and beam scanning rule information of the second satellite, a time when the beam of the second satellite is scanned to the position of the UE, and then the second satellite carries the determined time when the beam of the second satellite is scanned to the position of the UE in the handover request acknowledgement message, so that the first satellite can obtain, from the handover request acknowledgement message, the time when the beam of the second satellite is scanned to the position of the UE, and further, the first satellite calculates a second time when the handover command is issued, so as to control the UE to be in a state of establishing connection with the first satellite before the second time, thereby reducing the time of idle scanning of the UE and further reducing the handover delay.

In a second possible embodiment, as shown in fig. 6, a handover method for satellite communication includes:

s601, the second satellite sends the ephemeris information of the second satellite and the beam scanning rule information of the second satellite to the first satellite, and accordingly, the first satellite receives the ephemeris information of the second satellite and the beam scanning rule information of the second satellite.

In one implementation, the second satellite may send ephemeris information of the second satellite and beam scanning rule information of the second satellite to the first satellite based on an event-triggered manner; alternatively still, the second satellite may periodically transmit ephemeris information of the second satellite and beam scanning rule information of the second satellite to the first satellite.

S602, when determining that the UE needs to be switched from the first satellite to the second satellite, the first satellite sends switching request information to the second satellite; accordingly, the second satellite receives the handover request information.

S603, the second satellite responds to the switching request message and sends a switching request confirmation message to the first satellite; accordingly, the first satellite receives the handoff request acknowledge message.

In this embodiment, after receiving the handover request message, the second satellite may know that the UE wants to establish a connection with the second satellite, at this time, the second satellite may perform admission judgment, if the second satellite allows the UE to switch, it allocates a radio resource including a temporary identifier and the like to the UE, and sends handover request acknowledgement information to the target base station, so as to indicate to the first satellite that handover preparation is successful.

S604, the first satellite determines first information indicating a time when the beam of the second satellite is scanned to the position of the UE based on the ephemeris information of the second satellite, the beam scanning rule information of the second satellite, and the position information of the UE.

S605, the first satellite determines, based on the first information and the first time, a second time at which to send a handover command to the UE, where the handover command instructs the UE to access the second satellite, and the first time is the latest time at which the first satellite sends the handover command.

S606, the first satellite sends a switching command to the UE at a second moment; accordingly, the UE receives the handover command.

Wherein, S605 and S606 may refer to the description in S402 in the embodiment shown in fig. 4, and are not described herein.

In this embodiment, the first satellite determines, based on the position information of the UE, the ephemeris information of the second satellite, and the beam scanning rule information of the second satellite, a time when the beam of the second satellite scans the position of the UE, and then calculates, based on the determined time when the beam of the second satellite scans the position of the UE and the latest time when the first satellite can issue a handover command, a second time when the handover command is issued, so as to control the UE to be in a state of establishing connection with the first satellite before the second time, thereby reducing the time of idle scanning of the UE, and further reducing the handover delay.

Fig. 7 is a schematic structural diagram of an apparatus for satellite switching according to an embodiment of the present application. Specifically, as shown in fig. 7, the switching device of the satellite includes: a transceiver module 701 and a processing module 702.

In a first embodiment, the satellite switching device may be applied to a first satellite. The transceiver module 701 is configured to obtain first information, where the first information is used to indicate a time when a beam of a second satellite is scanned to a position of the UE, and the second satellite is a satellite that the UE needs to switch; a processing module 702, configured to determine, based on the first information and a first time, a second time when a handover command is sent to the UE, where the handover command indicates that the UE accesses the second satellite, and the first time is a latest time when the UE receives the handover command; the transceiver module 701 is further configured to send the handover command to the UE at the second time.

In one possible implementation, the transceiver module 701 is further configured to: transmitting second information to the second satellite, the second information indicating location information of the UE; receiving the first information sent by the second satellite, wherein the first information is determined by the second satellite based on the following information: ephemeris information of the second satellite, beam scanning rule information of the second satellite, and location information of the UE.

In one possible implementation, the second information is carried in a handover request message, where the handover request message is used by the first satellite to request from the second satellite that the UE needs to handover to the second satellite.

In one possible implementation, the first information is carried in a handover request confirm message that instructs the second device to allow the UE to handover from the first satellite to the second satellite.

In one possible implementation, the transceiver module 701 is further configured to: acquiring ephemeris information of the second satellite and beam scanning rule information of the second satellite; the processing module 702 is further configured to: the first information is determined based on the location information of the UE, ephemeris information of the second satellite, and beam scanning rule information of the second satellite.

In one possible implementation, the transceiver module 701 is further configured to: and receiving the ephemeris information of the second satellite and the beam scanning rule information of the second satellite, which are sent by the second satellite.

In one possible implementation, ephemeris information of the second satellite and beam scanning rule information of the second satellite are preset in the first satellite.

In one possible implementation, the transceiver module 701 is further configured to: receiving at least one measurement report sent by the UE, wherein the at least one measurement report corresponds to at least one satellite one by one, and each measurement report indicates the signal quality of a detection signal sent by the corresponding satellite; the processing module 702 is further configured to: the second satellite is determined from the at least one satellite based on the at least one measurement report.

In a second embodiment, the satellite switching device may be applied to a second satellite.

Specifically, the transceiver module 701 is configured to obtain second information sent by a first satellite, where the second information indicates location information of a UE that needs to be handed over from the first satellite to the second satellite; a processing module 702, configured to determine first information based on ephemeris information of the second satellite, beam scanning rule information of the second satellite, and location information of the UE, where the first information indicates a time when a beam of the second satellite is scanned to the location of the UE; the transceiver module 701 is further configured to: the first information is transmitted to the first satellite.

Fig. 8 is a schematic structural diagram of a satellite switching device according to another embodiment of the present application. The apparatus shown in fig. 8 may be used to perform the method described in any of the previous embodiments.

As shown in fig. 8, the apparatus 800 of the present embodiment includes: a memory 801, a processor 802, a communication interface 803, and a bus 804. Wherein the memory 801, the processor 802, and the communication interface 803 are communicatively connected to each other through a bus 804.

The memory 801 may be a Read Only Memory (ROM), a static storage device, a dynamic storage device, or a random access memory (random access memory, RAM). The memory 801 may store a program, and when the program stored in the memory 801 is executed by the processor 802, the processor 802 is configured to perform the respective steps of the methods shown in fig. 4 to 6.

The processor 802 may employ a general-purpose central processing unit (central processing unit, CPU), microprocessor, application specific integrated circuit (application specific integrated circuit, ASIC), or one or more integrated circuits for executing associated programs to implement the methods of the present application illustrated in fig. 4-6.

The processor 802 may also be an integrated circuit chip with signal processing capabilities. In implementation, various steps of the methods of fig. 4-6 of embodiments of the present application may be performed by integrated logic circuitry in hardware or by instructions in software in processor 802.

The processor 802 may also be a general purpose processor, a digital signal processor (digital signal processing, DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf programmable gate array (field programmable gate array, FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components. The disclosed methods, steps, and logic blocks 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 embodied directly in the execution of a hardware decoding processor, or in the execution of a combination of hardware and software modules in a decoding processor. The software modules may be located in a random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, etc. as well known in the art. The storage medium is located in the memory 801, and the processor 802 reads information in the memory 801, and in combination with its hardware, performs functions necessary for the unit included in the apparatus of the present application, for example, may perform various steps/functions of the embodiments shown in fig. 4 to 6.

Communication interface 803 may enable communication between apparatus 800 and other devices or communication networks using, but is not limited to, a transceiver-like transceiver.

Bus 804 may include a path for transferring information between components of apparatus 800 (e.g., memory 801, processor 802, communication interface 803).

It should be understood that the apparatus 800 shown in the embodiment of the present application may be an electronic device, or may be a chip configured in an electronic device.

The above embodiments may be implemented in whole or in part by software, hardware, firmware, or any other combination. When implemented in software, the above-described embodiments may be implemented in whole or in part in the form of a computer program product. The computer program product comprises one or more computer instructions or computer programs. When the computer instructions or computer program are loaded or executed on a computer, the processes or functions described in accordance with embodiments of the present application are produced in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from one website site, computer, server, or data center to another website site, computer, server, or data center by wired (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains one or more sets of available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. The semiconductor medium may be a solid state disk.

It should be understood that the term "and/or" is merely an association relationship describing the associated object, and means that three relationships may exist, for example, a and/or B may mean: there are three cases, a alone, a and B together, and B alone, wherein a, B may be singular or plural. In addition, the character "/" herein generally indicates that the associated object is an "or" relationship, but may also indicate an "and/or" relationship, and may be understood by referring to the context.

In the present application, "at least one" means one or more, and "a plurality" means two or more. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). 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 plural.

It should be understood that, in various embodiments of the present application, the sequence numbers of the foregoing processes do not mean the order of execution, and the order of execution of the processes should be determined by the functions and internal logic thereof, and should not constitute any limitation on the implementation process of the embodiments of the present application.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps 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 solution. 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 will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown 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 may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in 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 this understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform 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 U disk, a mobile hard disk, a read-only memory, a random access memory, a magnetic disk or an optical disk.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within 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 satellite handoff method applied to a first satellite, comprising:

acquiring first information, wherein the first information is used for indicating the moment when a beam of a second satellite is scanned to the position of User Equipment (UE), and the second satellite is a satellite which needs to be switched by the UE;

determining a second time for transmitting a switching command to the UE based on the first information and the first time, wherein the switching command indicates the UE to access to the second satellite, and the first time is the latest time when the UE receives the switching command;

and sending the switching command to the UE at the second moment.

2. The method of claim 1, wherein the obtaining the first information comprises:

transmitting second information to the second satellite, the second information indicating location information of the UE;

Receiving the first information sent by the second satellite, wherein the first information is determined by the second satellite based on the following information: ephemeris information of the second satellite, beam scanning rule information of the second satellite, and location information of the UE.

3. The method of claim 2, wherein the second information is carried in a handover request message for the first satellite to request from the second satellite that the UE needs to handover to the second satellite.

4. A method according to claim 2 or 3, wherein the first information is carried in a handover request confirm message, the handover request confirm message indicating that the second device allows the UE to handover from the first satellite to the second satellite.

5. The method of claim 1, wherein the obtaining the first information comprises:

acquiring ephemeris information of the second satellite and beam scanning rule information of the second satellite;

the first information is determined based on the location information of the UE, ephemeris information of the second satellite, and beam scanning rule information of the second satellite.

6. The method of claim 5, wherein the acquiring ephemeris information for the second satellite and beam sweep rule information for the second satellite comprises:

and receiving the ephemeris information of the second satellite and the beam scanning rule information of the second satellite, which are sent by the second satellite.

7. The method of claim 5, wherein ephemeris information for the second satellite and beam sweep rule information for the second satellite are preset in the first satellite.

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

receiving at least one measurement report sent by the UE, wherein the at least one measurement report corresponds to at least one satellite one by one, and each measurement report indicates the signal quality of a detection signal sent by the corresponding satellite;

the second satellite is determined from the at least one satellite based on the at least one measurement report.

9. A satellite handoff method applied to a second satellite, comprising:

acquiring second information sent by a first satellite, wherein the second information indicates the position information of User Equipment (UE) which needs to be switched from the first satellite to the second satellite;

Determining first information indicating a time when a beam of the second satellite is scanned to a position of the UE based on ephemeris information of the second satellite, beam scanning rule information of the second satellite, and position information of the UE;

the first information is transmitted to the first satellite.

10. The method of claim 9, wherein the first information is carried in a handover request confirm message that instructs the second device to allow the UE to handover from the first satellite to the second satellite.

11. A satellite switching device, for use with a first satellite, comprising:

the receiving and transmitting module is used for acquiring first information, wherein the first information is used for indicating the moment when a beam of a second satellite is scanned to the position of User Equipment (UE), and the second satellite is a satellite which needs to be switched by the UE;

the processing module is used for determining a second moment for sending a switching command to the UE based on the first information and the first moment, the switching command indicates the UE to access to the second satellite, and the first moment is the latest moment when the UE receives the switching command;

The transceiver module is further configured to send the handover command to the UE at the second time.

12. The apparatus of claim 11, wherein the transceiver module is further configured to:

13. The apparatus of claim 12, wherein the second information is carried in a handoff request message for the first satellite to request from the second satellite that the UE needs to handoff to the second satellite.

14. The apparatus according to claim 12 or 13, wherein the first information is carried in a handover request confirm message, the handover request confirm message indicating that the second device allows the UE to handover from the first satellite to the second satellite.

15. The apparatus of claim 11, wherein the transceiver module is further configured to:

the processing module is further configured to: the first information is determined based on the location information of the UE, ephemeris information of the second satellite, and beam scanning rule information of the second satellite.

16. The apparatus of claim 15, wherein the transceiver module is further configured to:

17. The apparatus of claim 15, wherein ephemeris information for the second satellite and beam sweep rule information for the second satellite are preset in the first satellite.

18. The apparatus of any one of claims 11 to 17, wherein the transceiver module is further configured to:

the processing module is further configured to: the second satellite is determined from the at least one satellite based on the at least one measurement report.

19. A satellite switching device, for use with a second satellite, comprising:

the receiving and transmitting module is used for acquiring second information sent by a first satellite, wherein the second information indicates the position information of User Equipment (UE) which needs to be switched from the first satellite to the second satellite;

a processing module configured to determine first information indicating a time at which a beam of the second satellite is scanned to a position of the UE based on ephemeris information of the second satellite, beam scanning rule information of the second satellite, and position information of the UE;

the transceiver module is further configured to: the first information is transmitted to the first satellite.

20. The apparatus of claim 19, wherein the first information is carried in a handover request confirm message that instructs the second device to allow the UE to handover from the first satellite to the second satellite.

21. A computer readable medium, characterized in that the computer readable medium stores a program code for computer execution, the program code comprising instructions for performing the method of any of claims 1 to 10.

22. A computer program product comprising computer program code for causing a computer to carry out the method according to any one of claims 1 to 10 when the computer program code is run on the computer.