CN113039832A

CN113039832A - Inter-system switching method and device

Info

Publication number: CN113039832A
Application number: CN201880099455.XA
Authority: CN
Inventors: 侯佳翔; 王振东; 葛欣明
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2018-11-22
Filing date: 2018-11-22
Publication date: 2021-06-25
Anticipated expiration: 2038-11-22
Also published as: WO2020103106A1; CN113039832B

Abstract

A method and a device for switching different systems are provided. The method comprises the following steps: the first network equipment receives first information and second information sent by the second network equipment, wherein the first information and the second information are respectively used for indicating a main carrier cell and one or more auxiliary carrier cells which are accessed by the terminal equipment before the inter-system handover, the first network equipment configures the main carrier cell as the main cell in an auxiliary cell group which is accessed by the terminal equipment after the inter-system handover, configures the auxiliary carrier cell as the auxiliary cell in the auxiliary cell group, and sends third information to the terminal equipment through the second network equipment so as to indicate the main cell and the auxiliary cell in the auxiliary cell group. Therefore, the terminal equipment can still keep communication connection with the main carrier cell and the auxiliary carrier cell before switching after the inter-system switching is carried out, so that the technical problems that the auxiliary carrier cell is released and the transmission rate of the terminal equipment is reduced due to the inter-system switching are effectively solved, and the data transmission continuity of the terminal equipment is ensured.

Description

Inter-system switching method and device

Technical Field

The present application relates to the field of wireless communications technologies, and in particular, to a method and an apparatus for inter-system handover.

Background

When a terminal device (user equipment, UE) simultaneously supporting two communication systems moves in a network, due to different coverage areas and different network deployment plans of the two communication systems, the network device may control the UE to perform inter-system switching between the LTE system and the NR system in order to maintain service continuity of the UE in a connected state.

Carrier Aggregation (CA) technology is a method for aggregating component carriers together to increase system bandwidth and improve uplink and downlink transmission rate. In the prior art, when a UE accesses a network device supporting a 5G NR communication scheme, if the network device supporting the 5G NR communication scheme employs a carrier aggregation technology to configure an auxiliary carrier cell for the UE, when the UE performs inter-system handover from the network device supporting the 5G NR communication scheme to another network device supporting a 4G LTE communication scheme, the originally configured auxiliary carrier cell is released, which may further cause a decrease in a transmission rate of the UE.

Disclosure of Invention

The application provides a method and a device for switching different systems, which are used for solving the technical problem that in the prior art, when UE performs different system switching between network equipment of different communication systems, the transmission rate is reduced.

In a first aspect, an embodiment of the present application provides a method for inter-system handover, where the method is executable by a first network device, and the method includes: the method comprises the steps that first network equipment receives first information and second information sent by second network equipment, wherein the first information is used for indicating a main carrier cell accessed by terminal equipment before inter-system switching, and the second information is used for indicating one or more auxiliary carrier cells accessed by the terminal equipment before inter-system switching; the first network equipment configures the primary carrier cell indicated by the first information as a primary cell in an auxiliary cell group (SCG) accessed by the terminal equipment after inter-system handover, and configures all or part of the secondary carrier cells indicated by the second information as auxiliary cells in the SCG; and the first network equipment sends third information to the terminal equipment through the second network equipment, wherein the third information is used for indicating a main cell and an auxiliary cell in the SCG.

In the embodiment of the application, the first network device can receive the first information and the second information sent by the second network device, and configuring an auxiliary cell group accessed by the terminal equipment after the inter-system handover according to the first information and the second information, wherein the primary carrier cell accessed by the terminal equipment indicated by the first information before the inter-system handover is configured as the primary cell in the secondary cell group, the secondary carrier cell accessed by the terminal equipment indicated by the second information before the inter-system handover is configured as the secondary cell in the secondary cell group, thus, the terminal equipment can still maintain communication connection with the main carrier cell and the auxiliary carrier cell before switching after the inter-system switching, therefore, the technical problem that the transmission rate of the terminal equipment is reduced due to the fact that the auxiliary carrier cell is released in the process of switching the different systems is effectively solved, and the continuity of data transmission of the terminal equipment is ensured.

In a possible design, the first network device configures the primary carrier cell indicated by the first information as a primary cell in a secondary cell group SCG to which the terminal device has access after inter-system handover, and may further send, to the second network device, fourth information used for indicating candidate cells determined by the first network device according to the first information and the second information and used for constituting an SCG, before configuring all or part of secondary carrier cells indicated by the second information as secondary cells in the SCG; the first network equipment receives fifth information sent by the second network equipment; the fifth information is used to indicate the SCG determined by the second network device according to the candidate cells, where the secondary cell of the SCG includes at least one secondary carrier cell of the one or more secondary carrier cells.

In the embodiment of the application, the first network device can directly configure the auxiliary carrier cell accessed by the terminal device before the inter-system handover as the auxiliary cell in the auxiliary cell group, and also can configure part of the auxiliary carrier cells as the auxiliary cells in the auxiliary cell group to be accessed after the inter-system handover by interacting with the second network device with the candidate cells in the auxiliary cell group.

In a possible design, the first network device may receive the first information and the second information sent by a core network element, where the first information and the second information are sent to the core network element by the second network device; the first network device may also receive the first information and the second information directly sent by the second network device.

In the embodiment of the present application, according to that the first network device and the second network device may communicate directly or indirectly through a core network element, the applicability of the inter-system handover method in the embodiment of the present application is effectively improved.

In one possible design, the first network device may be a network device supporting a long term evolution, LTE, communication system and the second network device may be a network device supporting a new wireless NR communication system.

In a second aspect, an embodiment of the present application further provides another inter-system handover method, where the method is executable by a second network device, and the method includes: the method comprises the steps that a second network device obtains first information and second information, and sends the first information and the second information to the first network device, wherein the first information is used for indicating a main carrier cell accessed by a terminal device before switching between different systems, and the second information is used for indicating one or more auxiliary carrier cells accessed by the terminal device before switching between different systems; the second network device receives third information sent by the first network device, and sends the third information to the terminal device, where the third information is used to indicate a primary cell and a secondary cell in a secondary cell group SCG accessed by the terminal device after inter-system handover, the primary cell is a primary carrier cell indicated by the first information, and the secondary cell includes all or part of secondary carrier cells indicated by the second information.

In this embodiment, the second network device may send first information and second information to the first network device, and indicate, to the first network device, the primary carrier cell and the secondary carrier cell that the terminal device accesses before the inter-system handover through the first information and the second information, so that the first network device may configure, according to the first information and the second information, the secondary cell group that the terminal device accesses after the inter-system handover, configure, as the primary cell in the secondary cell group, the primary carrier cell that the terminal device accesses before the inter-system handover, and configure, as the secondary cell in the secondary cell group, the secondary carrier cell that the terminal device accesses before the inter-system handover. Therefore, the terminal equipment can still keep communication connection with the main carrier cell and the auxiliary carrier cell before switching after the inter-system switching is carried out, so that the technical problem that the transmission rate of the terminal equipment is reduced due to the fact that the auxiliary carrier cell is released in the inter-system switching process is effectively solved, and the continuity of data transmission of the terminal equipment is ensured.

In a possible design, after the second network device sends the first information and the second information to the first network device, and before receiving the third information sent by the first network device, the second network device may further receive fourth information sent by the first network device, where the fourth information is used to instruct the first network device to determine, according to the first information and the second information, candidate cells for forming an SCG; and the second network device sends fifth information to the first network device, where the fifth information is used to indicate the SCG determined by the second network device according to each candidate cell, and a secondary cell of the SCG includes at least one secondary carrier cell of the one or more secondary carrier cells.

In this embodiment of the application, the second network device may receive the fourth information sent by the first network device, and configure, according to each candidate cell in the auxiliary cell group indicated in the fourth information by the first network device, at least one auxiliary carrier cell in the auxiliary carrier cells accessed by the terminal device before the inter-system handover as an auxiliary cell in the auxiliary cell group, thereby effectively improving the frequency spectrum resource utilization efficiency of the system and increasing the flexibility of the configuration of the auxiliary cell group.

In a possible design, the second network device may send the first information and the second information to a core network element, and send the first information and the second information to the first network device through the core network element; the second network device may also send the first information and the second information directly to the first network device.

In one possible design, the second network device may be a network device supporting a new wireless NR communication system and the first network device may be a network device supporting a long term evolution, LTE, communication system.

In a third aspect, an embodiment of the present application provides an apparatus, where the apparatus has a function of implementing the first aspect or the first network device in any possible design of the first aspect, where the function may be implemented by hardware, or may be implemented by hardware executing corresponding software, where the hardware or software includes one or more modules corresponding to the above functions.

In one possible design, the apparatus structurally includes a processing module and a transceiver module, and the processing module is configured to support the apparatus to perform the corresponding method steps in the first aspect or any one of the above-mentioned designs of the first aspect. The transceiver module is used for supporting communication between the device and a second network device or other communication devices. The apparatus may also include a memory module, coupled to the processing module, that stores program instructions and data necessary for the apparatus. As an example, the processing module may be a processor, the communication module may be a transceiver, and the storage module may be a memory.

In a fourth aspect, an embodiment of the present application provides an apparatus, where the apparatus has a function of implementing the second network device in any one of the possible designs of the second aspect or the second aspect, where the function may be implemented by hardware, or by hardware executing corresponding software, where the hardware or software includes one or more modules corresponding to the above functions.

In one possible design, the apparatus includes a processing module and a transceiver module in a structure, and the processing module is configured to support the apparatus to perform the corresponding method steps in any of the second aspect or the second aspect. The transceiver module is used for supporting communication between the device and the first network equipment or other communication equipment. The apparatus may also include a memory module, coupled to the processing module, that stores program instructions and data necessary for the apparatus. As an example, the processing module may be a processor, the communication module may be a transceiver, and the storage module may be a memory.

In a fifth aspect, embodiments of the present application provide a computer-readable storage medium, which stores computer-readable instructions, and when the computer-readable instructions are read and executed by a computer, the computer can execute the method in any one of the possible designs of the first aspect or the second aspect.

In a sixth aspect, embodiments of the present application provide a computer program product, which when read and executed by a computer, enables the computer to perform the method of any one of the possible designs of the first aspect or the second aspect.

In a seventh aspect, an embodiment of the present application provides a chip, where the chip is connected to a memory, and is configured to read and execute a software program stored in the memory, so as to implement the method in any one of the possible designs of the first aspect or the second aspect. In an eighth aspect, an embodiment of the present application provides a communication system, where the communication system includes the above first network device and a second network device, where the first network device is configured to perform the corresponding method steps in any design of the above first aspect or first aspect, and the second network device is configured to perform the corresponding method steps in any design of the above second aspect or second aspect.

Drawings

Fig. 1 is a schematic diagram of a network architecture suitable for use in the embodiments of the present application;

fig. 2 is a schematic flowchart of a method for inter-system handover according to an embodiment of the present disclosure;

fig. 3 is a handover flowchart provided in a first embodiment of the present application;

fig. 4 is a handover flowchart provided in a second embodiment of the present application;

FIG. 5 is a schematic diagram of an apparatus provided in an embodiment of the present application;

FIG. 6 is a schematic structural diagram of another apparatus provided in an embodiment of the present application;

fig. 7 is a schematic structural diagram of another apparatus provided in the embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application are described in detail below with reference to the accompanying drawings. It is noted that the terminology used in the description of the embodiments section of the present application is for the purpose of describing particular embodiments of the present application only and is not intended to be limiting of the present application.

Hereinafter, some terms in the embodiments of the present application are explained to facilitate understanding by those skilled in the art.

1) Terminal equipment, including devices that provide voice and/or data connectivity to a user, may include, for example, handheld devices with wireless connection capability or processing devices connected to wireless modems. The terminal device may communicate with a core network via a Radio Access Network (RAN), exchanging voice and/or data with the RAN. The terminal device may include a User Equipment (UE), a wireless terminal device, a mobile terminal device, a subscriber unit (subscriber unit), a subscriber station (subscriber station), a mobile station (mobile), a remote station (remote station), an Access Point (AP), a remote terminal device (remote terminal), an access terminal device (access terminal), a user terminal device (user terminal), a user agent (user agent), a user equipment (user device), or the like. For example, mobile phones (or so-called "cellular" phones), computers with mobile terminal equipment, portable, pocket, hand-held, computer-included or vehicle-mounted mobile devices, smart wearable devices, and the like may be included. For example, Personal Communication Service (PCS) phones, cordless phones, Session Initiation Protocol (SIP) phones, Wireless Local Loop (WLL) stations, Personal Digital Assistants (PDAs), and the like. Also included are constrained devices, such as devices that consume less power, or devices that have limited storage capabilities, or devices that have limited computing capabilities, etc. Examples of information sensing devices include bar codes, Radio Frequency Identification (RFID), sensors, Global Positioning Systems (GPS), laser scanners, and the like.

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, smart helmets, smart jewelry and the like for monitoring physical signs.

2) A network device, e.g., including a base station (e.g., access point), may refer to a device in an access network that communicates over the air, through one or more cells, with wireless terminal devices. The network device may be configured to interconvert received air frames and Internet Protocol (IP) packets as a router between the terminal device and the rest of the access network, which may include an IP network. The network device may also coordinate attribute management for the air interface. For example, the network device may include an evolved Node B (NodeB or eNB or e-NodeB) in a Long Term Evolution (LTE) system or an evolved LTE system (LTE-Advanced, LTE-a), or may also include a next generation Node B (gNB) in a fifth generation mobile communication technology (5G) New Radio (NR) system, or may also include a Centralized Unit (CU) and a Distributed Unit (DU) in a cloud access network (cloud ran) system, which is not limited in the embodiments of the present application.

3) Carrier aggregation refers to a technology in which a network device configures multiple carriers for a terminal device, and the terminal device and the network device perform data transmission together using the multiple carriers. The multiple carriers generally include a Primary Carrier Component (PCC) and one or more secondary carriers (SCCs). A cell operating in a primary carrier is a primary carrier cell (PCell), the PCell is a cell when a terminal initially accesses, and a base station where the PCell is located is responsible for performing Radio Resource Control (RRC) communication with the terminal. A cell operating on a secondary carrier is a secondary carrier cell (SCell), and the SCell may provide additional radio resources for a terminal.

4) Dual Connectivity (DC), which is a technology in which a terminal device establishes and maintains communication connections with at least two network devices simultaneously, and performs data transmission using radio resources provided by the at least two network devices. The at least two network devices are connected by a non-ideal backhaul link and may be network devices supporting different access technologies. Under dual connectivity, two cell groups are included, a Master Cell Group (MCG) and a Secondary Cell Group (SCG), respectively, and both the MCG and the SCG may include one master cell and one or more secondary cells. Correspondingly, the network device in charge of managing the MCG among the at least two network devices is a primary network device for providing a control plane connection between the terminal device and the core network, and the network device in charge of managing the SCG is a secondary network device for providing additional wireless resources for the terminal.

6) The inter-system handover refers to a handover of a terminal device between two networks of different communication systems, for example, the terminal device is handed over from a cell of an originally accessed LTE network to a cell of a 5G network, or may be handed over from a cell of an originally accessed 5G network to a cell of an LTE network.

7) The terms "system" and "network" in the embodiments of the present application may be used interchangeably. The "plurality" means two or more, and in view of this, the "plurality" may also be understood as "at least two" in the embodiments of the present application. By "at least two", two or more strips are to be understood, for example two, three or more strips. "at least one" is to be understood as meaning one or more, for example one, two or more, strips. Similarly, the understanding of the description of "a plurality" and the like is similar. "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. In addition, the character "/" generally indicates that the preceding and following related objects are in an "or" relationship, unless otherwise specified.

In the following description, unless specified to the contrary, "first," "second," etc. ordinal terms are used for distinguishing between the description and not for indicating or implying relative importance, nor order.

The technical scheme provided by the embodiment of the application can be applied to a 5G system, an evolved long term evolution (LTE-A) system and the like. In addition, the technical scheme can also be applied to future-oriented communication technology. It should be understood that the network structure described in the embodiment of the present application is for more clearly illustrating the technical solution of the embodiment of the present application, and does not constitute a limitation to the technical solution provided in the embodiment of the present application, and as a person having ordinary skill in the art knows, along with the evolution of the network architecture, the technical solution provided in the embodiment of the present application is also applicable to similar technical problems.

Fig. 1 illustrates an application scenario of the embodiment of the present application, or a network architecture to which the embodiment of the present application is applied, where the network architecture may be a network architecture of a next generation radio access network (NG-RAN) system. As shown in fig. 1, the 5G base stations (5G eNodeB, gNB) in the network architecture provide NR user plane and control plane protocols towards the terminal device, and the gNB is connected to the core network of the 5G system, the non-5G base stations (non 5G eNodeB, ng-eNB) provide evolved-terrestrial radio access network (E-UTRAN) user plane and control plane protocols towards the terminal device, and the ng-eNB is also connected to the core network of the 5G system. The gNB and the NG-eNB are interconnected through an Xn interface, and the gNB and the NG-eNB are both connected to an access and mobility management function (AMF) or a User Plane Function (UPF) in a 5G core network (5GC) through the NG interface. Although the terminal device is not shown in fig. 4, in fact, each of the gnbs or ng-gnbs in fig. 4 may serve one or more terminal devices, and the technical solution provided by the embodiment of the present application may be implemented by the gNB serving the terminal device and/or the ng-gNB serving the terminal device.

Based on the above network architecture, fig. 2 exemplarily shows a method for inter-system handover provided by the embodiment of the present application, and as shown in fig. 2, the method includes:

step S201: the second network device acquires the first information and the second information and sends the first information and the second information to the first network device. The first network equipment is network equipment which is accessed by the terminal equipment after the inter-system switching is carried out, the second network equipment is network equipment which is accessed by the terminal equipment before the inter-system switching is carried out, the first information is used for indicating a main carrier cell which is accessed by the terminal equipment before the inter-system switching, and the second information is used for indicating one or more auxiliary carrier cells which are accessed by the terminal equipment before the inter-system switching;

in the specific implementation of step S201, the terminal device is in a state of accessing to a second network device, and the second network device may transmit data for the terminal device by using the radio resources of the primary carrier cell and the one or more secondary carrier cells simultaneously. If the second network device determines to switch the trigger terminal device to the first network device, the second network device may send the first information and the second information to the second network device before the trigger terminal device performs inter-system switching, so as to notify the first network device of information of the primary carrier cell and the secondary carrier cell used by the terminal device for carrier aggregation before switching. In one possible design, the first information may include cell identities of primary carrier cells and the second information may include cell identities of one or more secondary carrier cells.

It should be noted that, in the embodiment of the present application, the first network device and the second network device are network devices conforming to different communication systems. Specifically, the first network device is a network device supporting an LTE communication system, and the second network device is a network device supporting a 5G NR communication system. In one example, the first network device may be a NG-eNB network node in a NG-RAN system and the second network device may be a gNB network node in the NG-RAN system.

The first network device and the second network device may each be connected via the NG interface to a core network element, which may be an AMF or a UPF in a 5G core network as shown in the network architecture in fig. 1. Depending on the different locations of the first network device and the second network device in the NG-RAN network, there may or may not be a directly interconnected Xn interface between the first network device and the second network device. If an Xn interface exists between the first network device and the second network, it means that the first network device and the second network device can directly communicate, for example, the second network device can directly send the first information and the second information to the first network device without forwarding through the AMF or the UPF. If the Xn interface does not exist between the first network device and the second network device, it indicates that the first network device and the second network device must forward through the AMF or the UPF to realize indirect communication, for example, the second network device may send the first information and the second information to the AMF or the UPF through the NG interface between the second network device and the AMF or the UPF, and send the first information and the second information to the first network device through the NG interface between the network element of the AMF or the UPF and the first network device via the AMF or the UPF. It should be understood that, in the case that the first network device and the second network device have Xn interfaces directly interconnected, the second network device may also send the first information and the second information to the AMF or the UPF first, and then send the first information and the second information to the first network device by the AMF or the UPF, which is not specifically limited in this embodiment of the present application. Moreover, after the first network device and the second network device determine the interaction manner, that is, refer to a manner of performing direct communication or indirect communication, other information, for example, third information, fourth information, fifth information, and the like, which will be mentioned later, may also be exchanged between the first network device and the second network device, and the same interaction manner may also be used for transceiving, which is not described in detail in this embodiment of the present application.

Step S202: the method comprises the steps that first network equipment receives first information and second information sent by second network equipment;

step S203: the first network equipment configures the main carrier cell indicated in the first information as a main cell in an SCG (secondary cell group) accessed by the terminal equipment after the inter-system handover, and configures all or part of the auxiliary carrier cells indicated in the second information as auxiliary cells in the SCG accessed by the terminal equipment after the inter-system handover;

in the specific implementation of step S202 and step S203, the first network device may receive the first information and the second information sent by the second network device, and configure the primary carrier cell accessed by the terminal device before the inter-system handover, which is indicated in the first information, as: the terminal device configures the primary cell in the SCG to be accessed after the inter-system handover, and configures all or part of the secondary carrier cells accessed by the terminal device indicated in the second information before the inter-system handover as: and the terminal equipment accesses the auxiliary cell in the SCG after the inter-system switching.

It should be noted that the primary carrier cell, the secondary carrier cell, and the primary cell and the secondary cell in the SCG involved in this step are concepts in different communication technologies, the primary carrier cell and the secondary carrier cell respectively correspond to a primary carrier and a secondary carrier used by the second network device when the carrier aggregation technology is used for transmitting data for the terminal device, and the primary cell and the secondary cell are configured in a secondary cell group configured when the first network device uses the dual connectivity technology for transmitting data for the terminal device, and both the primary cell and the secondary cell are set for the purpose of providing additional wireless resources for the terminal device.

The terminal equipment can keep communication connection with the main carrier cell and one or more auxiliary carrier cells before the inter-system handover, and after the inter-system handover, the terminal equipment can keep communication connection with each cell arranged in the SCG, and can also access the cell under the first network equipment, use the wireless resources in the cell and perform mobility management on the terminal equipment by the cell. The cell under the first network device is referred to as a master cell group MCG to which the terminal device is connected after the inter-system handover, and the MCG may include one or more cells, and for simplicity of description, only one cell is taken as an example.

Further, in order to keep the transmission rate of the terminal device stable before and after the handover, the first network device may configure all or a part of the original one or more secondary carrier cells as the secondary cells in the SCG according to the transmission bandwidth requirement of the terminal device.

Step S204: and the first network equipment sends third information to the terminal equipment through the second network equipment, wherein the third information is used for indicating the primary cell and the secondary cell in the SCG configured by the first network equipment.

In a possible design, before configuring the dual connectivity SCG, that is, before performing step 203, the first network device may further send fourth information to the second network device, where the fourth information is used to instruct the first network device to determine, according to the primary carrier cell and the one or more secondary carrier cells indicated by the first information and the second information, respective candidate cells for constructing the SCG, for example, cell identifiers of the respective candidate cells may be included in the fourth information.

Thus, after receiving the fourth information, the second network device may determine each cell in the SCG together according to each candidate cell of the SCG provided by the first network device, the main carrier cell and the auxiliary carrier cell currently accessed by the terminal device, and each cell in the second network device, and send the fifth information carrying the information of the SCG (for example, the cell identifier of each cell in the SCG) to the first network device.

In this embodiment of the application, the fifth information is used to indicate an SCG that is determined by the second network device according to each candidate cell and that allows the first network device to configure dual-connectivity for use in different systems, where a primary cell in the SCG is a primary carrier cell accessed by the terminal device when performing carrier aggregation before switching between different systems, and secondary cells in the SCG may be one or more secondary cells, where the secondary cells may include at least one secondary carrier cell connected when the terminal device performs carrier aggregation before switching between different systems, and/or other cells that are different from the primary carrier cell and the secondary carrier cell in the cell of the first network device.

Furthermore, after receiving the fifth information, the first network device may configure the SCG according to the primary cell and the secondary cell of the SCG indicated in the fifth information by the second network device.

In a specific implementation of step S204, after the configuration is completed, the first network device may send third information to the terminal device through the second network device, where the third information is used to indicate the primary cell and the secondary cell in the SCG accessed by the terminal device after the inter-system handover. That is, since the terminal device is connected to the second network device before the inter-system handover, the first network device may send the third information to the second network device, and the second network device sends the third information to the terminal device, so as to notify the terminal device to configure the SCG according to the third information when the inter-system handover is performed. Thereafter, the second network device may send an RRC connection reconfiguration request message to the terminal device to trigger the terminal device to start handover. In a possible design, the third information may configure configuration coding information of the SCG for the first network device, so that when the second network device triggers the terminal device to perform inter-system handover, the terminal device may directly configure the dual-connection SCG according to the configuration coding information indicated in the third information, thereby ensuring continuity of data transmission before and after handover of the terminal device.

In the embodiment of the application, before the terminal device performs inter-system handover, the second network device may configure one main carrier cell and one or more auxiliary carrier cells for the terminal device by using a carrier aggregation technology, and the terminal device establishes communication connection with the one main carrier cell and the one or more auxiliary carrier cells at the same time. In order to enable the data transmission of the terminal device before and after the inter-system handover to be continuous and uninterrupted and the transmission rate to be stable, the second network device may send first information and second information respectively indicating the main carrier cell and the auxiliary carrier cell to the first network device before triggering the terminal device to perform the inter-system handover, so that the first network device configures the SCG to be accessed by the terminal device after the inter-system handover according to the first information and the second information. The first network device may configure the primary carrier cell indicated by the first information as a primary cell in the SCG, and configure the secondary carrier cell indicated by the second information as a secondary cell in the SCG. Therefore, after the different systems are switched, the terminal equipment can simultaneously connect the cell of the first network equipment and each cell in the SCG by using the dual connection technology, so that the technical problem that the transmission rate of the terminal equipment is reduced due to the fact that the auxiliary carrier cell is released in the different systems switching process is effectively solved.

The technical solutions provided in the embodiments of the present application are described in detail below with reference to two specific embodiments.

Fig. 3 is a handover flowchart for performing inter-system handover through an NG interface according to a first embodiment of the present application, and in fig. 3, a UE is handed over from an initially accessed gNB inter-system to an NG-eNB. As shown in fig. 3, the handover process specifically includes:

1. the method includes that a source gNB triggers UE to perform inter-system handover to a 4G LTE communication system through an NG interface, the source gNB sends a handover request (handover required) message to an AMF, and information of a primary carrier cell and a secondary carrier cell, which are subjected to carrier aggregation by the source gNB, is carried in a source to target transparent container (source to target transparent container) cell in the handover required message, wherein the information can be identifiers of the primary carrier cell and the secondary carrier cell, and the identifiers of the primary carrier cell and the secondary carrier cell can be used for example.

2. After receiving the handover required message, the AMF sends a source to target transfer container cell in the handover required message to a target ng-eNB through a handover request message.

3. The target NG-eNB uses the carrier aggregation information (i.e., information of the primary carrier cell and the secondary carrier cell) transferred by the source gNB to perform the addition of the 4G 5G dual connectivity (NG-RAN E-UTRA-NR dual connectivity, NGEN-DC) SCG under the NG-RAN.

4. After the SCG is successfully added, the target ng-eNB encapsulates an RRC reconfiguration (reconfiguration) message carrying SCG configuration information into a target to source transparent container (target to source container) cell of a handover request acknowledgement (handover request acknowledge) message, and sends the cell to the AMF, and the cell is brought back to the source gNB by the AMF through a handover command (handover command) message, so as to notify the UE to directly configure the SCG when performing inter-system handover.

5. And the source gNB sends the RRC reconfiguration message to the UE to trigger the UE to perform inter-system switching, the UE configures the SCG by using the SCG configuration information in the RRC reconfiguration message, and after the configuration is completed, the source gNB sends an RRC reconfiguration completion message to the target ng-eNB.

6. The target ng-eNB sends a handover notification message to the AMF, and the AMF sends a UE context release message to the source gNB.

Fig. 4 is a handover flowchart for performing inter-system handover through an Xn interface according to a second embodiment of the present application, and in fig. 4, the UE is also handed over from the initial access gNB to the ng-eNB. As shown in fig. 4, the handover process specifically includes:

1. the method comprises the steps that a source gNB triggers inter-system handover to a 4G LTE communication system through an Xn interface, the source gNB sends a handover request (handover request) message to a target ng-eNB, and information of a main carrier cell and an auxiliary carrier cell which are subjected to carrier aggregation by the source gNB is carried in an RRC context (RRC context) cell of the handover request message, wherein the information can be identifications of the main carrier cell and the auxiliary carrier cell.

2. The target ng-eNB uses the carrier aggregation information (i.e., information of the primary and secondary carrier cells) communicated by the source gNB to make the addition of the NGEN-DC SCG.

3. After the SCG is successfully added, the target NG-eNB encapsulates an RRC reconfiguration (reconfiguration) message carrying SCG configuration information into a target NG-RAN node to source node transparent container (target NG-RAN node to source NG-RAN node transit container) cell of a handover request response (handover request acknowledge) message, and brings the cell back to the source gNB, so as to notify the UE to directly configure the SCG when performing inter-system handover.

4. And the source gNB sends the RRC reconfiguration message to the UE, triggers the UE to carry out inter-system switching, configures the SCG by using the SCG configuration information in the RRC reconfiguration message, and sends an RRC reconfiguration completion message to the target ng-eNB after the UE configuration is completed.

5. The target ng-eNB sends a UE context release message to the source gNB.

Based on the same inventive concept, the embodiment of the application also provides a device. As shown in fig. 5, a schematic structural diagram of an apparatus provided in this embodiment of the present application, where the apparatus may perform the actions of the first network device or the second network device in the foregoing method embodiments, the apparatus 500 includes: a processing module 510 and a transceiver module 520.

When the apparatus 500 executes the action on the first network device side, the processing module 510 and the transceiver module 520 respectively execute the following steps:

the transceiver module 520 receives first information and second information sent by a second network device, where the first information is used to indicate a primary carrier cell accessed by a terminal device before inter-system handover, and the second information is used to indicate one or more secondary carrier cells accessed by the terminal device before inter-system handover; the processing module 510 configures the primary carrier cell indicated by the first information as a primary cell in a secondary cell group SCG accessed by the terminal device after inter-system handover, and configures the secondary carrier cell indicated by the second information as a secondary cell in the SCG; the transceiver module 520 sends third information to the terminal device through the second network device, where the third information is used to indicate the primary cell and the secondary cell in the SCG.

When the apparatus 500 executes the operation of the second network device, the processing module 510 and the transceiver module 520 respectively execute the following steps:

the processing module 510 obtains the first information and the second information; the transceiver module 520 sends the first information and the second information to a first network device, where the first information is used to indicate a primary carrier cell accessed by a terminal device before inter-system handover, and the second information is used to indicate one or more secondary carrier cells accessed by the terminal device before inter-system handover; and the third information is used for indicating a main cell and an auxiliary cell in an auxiliary cell group SCG accessed by the terminal equipment after the inter-system handover, the main cell is a main carrier cell indicated by the first information, and the auxiliary cell comprises all or part of auxiliary carrier cells indicated by the second information.

It should be understood that the processing module 510 in the embodiments of the present invention may be implemented by a processor or a processor-related circuit component, and the transceiver module 520 may be implemented by a transceiver or a transceiver-related circuit component.

Fig. 6 is a schematic view of another structure of the device provided in the embodiment of the present application. The apparatus 600 comprises a processor 610, a memory 620 and a transceiver 630, wherein the memory 620 stores instructions or programs, and the processor 610 is configured to execute the instructions or programs stored in the memory 620. When the instructions or programs stored in the memory 620 are executed, the processor 610 is configured to perform the operations performed by the processing module 510 in the above embodiments, and the transceiver 630 is configured to perform the operations performed by the transceiver module 520 in the above embodiments.

The embodiment of the present application further provides a communication apparatus, which may be a chip, a network device (such as a base station), a circuit, or other network devices. The communication apparatus includes one or more processors, and the one or more processors can implement the actions performed by the first network device or the second network device in the method embodiment shown in fig. 2.

When the communication device is a network device, fig. 7 shows a schematic structural diagram of a network device, such as a schematic structural diagram of a base station. As shown in fig. 7, the base station may be applied to the system shown in fig. 1, and performs the functions of the first network device in the above method embodiment. The base station 700 may include one or more radio frequency units, such as a Remote Radio Unit (RRU) 701 and one or more baseband units (BBUs) (which may also be referred to as digital units, DUs) 702. The RRU 701 may be referred to as a transceiver unit, a transceiver circuit, or a transceiver, etc., and may include at least one antenna 7011 and a radio frequency unit 7012. The RRU 701 section is mainly used for transceiving radio frequency signals and converting the radio frequency signals and baseband signals, for example, to send the first indication information described in the above embodiment to a terminal device. The BBU 702 is mainly used for performing baseband processing, controlling a base station, and the like. The RRU 701 and the BBU 702 may be physically disposed together or may be physically disposed separately, that is, distributed base stations.

The BBU 702 is a control center of the base station, and may also be referred to as a processing unit, and is mainly used for performing baseband processing functions, such as channel coding, multiplexing, modulation, spreading, and the like. For example, the BBU (processing unit) 702 can be used to control the base station to execute the operation flow related to the network device in the above method embodiment.

In an example, the BBU 702 may be formed by one or more boards, and the boards may jointly support a radio access network (e.g., an LTE network) with a single access indication, or may respectively support radio access networks (e.g., LTE networks, 5G networks, or other networks) with different access schemes. The BBU 702 further includes a memory 7021 and a processor 7022, the memory 7021 being configured to store necessary instructions and data. For example, the memory 7021 stores the correspondence between the codebook indices and the precoding matrices in the above-described embodiments. The processor 7022 is configured to control the base station to perform necessary actions, for example, to control the base station to perform the operation flows related to the network device in the above-described method embodiments. The memory 7021 and the processor 7022 may serve one or more boards. That is, the memory and processor may be provided separately on each board. Multiple boards may share the same memory and processor. In addition, each single board can be provided with necessary circuits

An embodiment of the present application further provides a computer-readable storage medium, where the computer-readable storage medium stores computer-readable instructions, and when the computer reads and executes the computer-readable instructions, the computer is enabled to execute the method on the first network device side in any of the above method embodiments.

An embodiment of the present application provides a computer program product, which, when being read and executed by a computer, enables the computer to execute the method on the first network device side in any one of the above method embodiments.

The embodiment of the present application provides a chip, where the chip is connected to a memory, and is configured to read and execute a software program stored in the memory, so as to implement the method on the first network device side in any method embodiment described above.

An embodiment of the present application provides a computer-readable storage medium, on which instructions are stored, and when executed, the instructions perform the method on the second network device side in the above method embodiment.

Embodiments of the present application provide a computer program product containing instructions, which when executed perform the method on the second network device side in the above method embodiments.

The embodiment of the present application provides a chip, where the chip is connected to a memory, and is configured to read and execute a software program stored in the memory, so as to implement the method on the second network device side in any of the above method embodiments.

An embodiment of the present application provides a communication system, where the system includes a first network device and a second network device, where the first network device may be configured to execute a method on a first network terminal device side in any of the above method embodiments, and the second network device may be configured to execute a method on a second network device side in any of the above method embodiments.

It should be understood that the processor mentioned in the embodiments of the present application may be a Central Processing Unit (CPU), and may also be other general purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It will also be appreciated that the memory referred to in the embodiments of the 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 PROM (EPROM), an electrically Erasable EPROM (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, enhanced SDRAM, SLDRAM, Synchronous Link DRAM (SLDRAM), and direct rambus RAM (DR RAM).

It should be noted that when the processor is a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, the memory (memory module) is integrated in the processor.

It should be noted that the memory described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It should also be understood that reference herein to first, second, third, fourth, and various numerical designations is made only for ease of description and should not be used to limit the scope of the present application.

It should be understood that the term "and/or" herein is merely one type of association relationship that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of the processes should be determined by their functions and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

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 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 of 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.

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

A method for inter-system handover, the method comprising:

the method comprises the steps that first network equipment receives first information and second information sent by second network equipment, wherein the first information is used for indicating a main carrier cell accessed by terminal equipment before inter-system switching, and the second information is used for indicating one or more auxiliary carrier cells accessed by the terminal equipment before inter-system switching;

the first network equipment configures the primary carrier cell indicated by the first information as a primary cell in an auxiliary cell group (SCG) accessed by the terminal equipment after inter-system handover, and configures all or part of the secondary carrier cells indicated by the second information as auxiliary cells in the SCG;

and the first network equipment sends third information to the terminal equipment through the second network equipment, wherein the third information is used for indicating a main cell and an auxiliary cell in the SCG.
The method according to claim 1, wherein the first network device configures the primary carrier cell indicated by the first information as a primary cell in a secondary cell group SCG accessed by the terminal device after inter-system handover, and before configuring all or part of secondary carrier cells indicated by the second information as secondary cells in the SCG, further comprising:

the first network device sends fourth information to the second network device, wherein the fourth information is used for indicating each candidate cell which is determined by the first network device according to the first information and the second information and is used for forming the SCG;

the first network equipment receives fifth information sent by the second network equipment; the fifth information is used to indicate the SCG determined by the second network device according to the candidate cells, where the secondary cell of the SCG includes at least one secondary carrier cell of the one or more secondary carrier cells.
The method of claim 1 or 2, wherein the first network device receives the first information and the second information sent by the second network device, and comprises:

the first network device receives the first information and the second information sent by a core network element, and the first information and the second information are sent to the core network element by the second network device; alternatively, the first and second electrodes may be,

and the first network equipment receives the first information and the second information which are directly sent by the second network equipment.
The method of claim 3, wherein the first network device is a network device supporting a Long Term Evolution (LTE) communication system, and wherein the second network device is a network device supporting a new wireless NR communication system.
A method for inter-system handover, the method comprising:

the method comprises the steps that a second network device obtains first information and second information, and sends the first information and the second information to the first network device, wherein the first information is used for indicating a main carrier cell accessed by a terminal device before switching between different systems, and the second information is used for indicating one or more auxiliary carrier cells accessed by the terminal device before switching between different systems;

the second network device receives third information sent by the first network device, and sends the third information to the terminal device, where the third information is used to indicate a primary cell and a secondary cell in a secondary cell group SCG accessed by the terminal device after inter-system handover, the primary cell is a primary carrier cell indicated by the first information, and the secondary cell includes all or part of secondary carrier cells indicated by the second information.
The method of claim 5, wherein after the second network device sends the first information and the second information to the first network device, and before receiving third information sent by the first network device, further comprising:

the second network device receives fourth information sent by the first network device, where the fourth information is used to instruct the first network device to determine candidate cells for forming an SCG according to the first information and the second information;

and the second network device sends fifth information to the first network device, where the fifth information is used to indicate the SCG determined by the second network device according to each candidate cell, and a secondary cell of the SCG includes at least one secondary carrier cell of the one or more secondary carrier cells.
The method of claim 5 or 6, wherein the second network device sends the first information and the second information to the first network device, and wherein the sending comprises:

the second network device sends the first information and the second information to a core network element, and the first information and the second information are sent to the first network device through the core network element; alternatively, the first and second electrodes may be,

and the second network equipment directly sends the first information and the second information to the first network equipment.
The method of claim 7, wherein the second network device is a network device supporting a new wireless NR communication system, and wherein the first network device is a network device supporting a Long Term Evolution (LTE) communication system.
An apparatus, characterized in that the apparatus comprises:

a transceiver module, configured to receive first information and second information sent by a second network device, where the first information is used to indicate a primary carrier cell accessed by a terminal device before inter-system handover, and the second information is used to indicate one or more secondary carrier cells accessed by the terminal device before inter-system handover;

a processing module, configured to configure the primary carrier cell indicated by the first information as a primary cell in an secondary cell group SCG to which the terminal device is accessed after inter-system handover, and configure all or part of the secondary carrier cells indicated by the second information as secondary cells in the SCG;

the transceiver module is further configured to send third information to the terminal device through the second network device, where the third information is used to indicate a primary cell and a secondary cell in the SCG.
The apparatus of claim 9, wherein after the transceiver module receives the first information and the second information sent by the second network device, the transceiver module configures the primary carrier cell indicated by the first information as a primary cell in a secondary cell group SCG accessed by the terminal device after the inter-system handover, and configures all or part of secondary carrier cells indicated by the second information as secondary cells in the SCG, and before the transceiver module configures all or part of secondary carrier cells indicated by the second information as secondary cells in the SCG, further configured to:

sending fourth information to the second network device, where the fourth information is used to indicate each candidate cell determined by the first network device according to the first information and the second information, where the candidate cell is used to form an SCG; and the number of the first and second groups,

receiving fifth information sent by the second network equipment; the fifth information is used to indicate the SCG determined by the second network device according to the candidate cells, where the secondary cell of the SCG includes at least one secondary carrier cell of the one or more secondary carrier cells.
The apparatus according to claim 9 or 10, wherein the transceiver module is specifically configured to:

receiving the first information and the second information sent by a core network element, where the first information and the second information are sent to the core network element by the second network device; alternatively, the first and second electrodes may be,

and receiving the first information and the second information directly sent by the second network equipment.
The apparatus of claim 11, wherein the apparatus is a network device supporting a Long Term Evolution (LTE) communication system, and wherein the second network device is a network device supporting a new wireless NR communication system.
An apparatus, characterized in that the apparatus comprises:

the processing module is used for acquiring first information and second information;

a transceiver module, configured to send the first information and the second information to a first network device, where the first information is used to indicate a primary carrier cell accessed by a terminal device before inter-system handover, and the second information is used to indicate one or more secondary carrier cells accessed by the terminal device before inter-system handover; and the third information is used for indicating a main cell and an auxiliary cell in an auxiliary cell group SCG accessed by the terminal equipment after the inter-system handover, the main cell is a main carrier cell indicated by the first information, and the auxiliary cell comprises all or part of auxiliary carrier cells indicated by the second information.
The apparatus of claim 13, wherein the transceiver module is further configured to:

after the first information and the second information are sent to a first network device and before third information sent by the first network device is received, receiving fourth information sent by the first network device, wherein the fourth information is used for indicating each candidate cell which is determined by the first network device according to the first information and the second information and is used for forming the SCG;

and sending fifth information to the first network device, where the fifth information is used to instruct the apparatus to determine an SCG according to the candidate cells, and a secondary cell of the SCG includes at least one secondary carrier cell of the one or more secondary carrier cells.
The apparatus according to claim 13 or 14, wherein the transceiver module is specifically configured to:

sending the first information and the second information to a core network element, and sending the first information and the second information to first network equipment through the core network element; alternatively, the first and second electrodes may be,

and directly sending the first information and the second information to the first network equipment.
The apparatus of claim 15, wherein the second network device is a network device supporting a new wireless NR communication system, and wherein the first network device is a network device supporting a long term evolution, LTE, communication system.
A communications apparatus comprising at least one processor coupled with at least one memory:

the at least one processor configured to execute computer programs or instructions stored in the at least one memory to cause the apparatus to perform the method of any of claims 1-8.
A computer-readable storage medium, having stored thereon a computer program or instructions, which, when read and executed by a computer, cause the computer to perform the method of any one of claims 1 to 8.