CN115334609A

CN115334609A - Channel switching method and device of mobile terminal

Info

Publication number: CN115334609A
Application number: CN202211257500.4A
Authority: CN
Inventors: 邓勇志; 王贻先; 周江平
Original assignee: Wuhan Shiju Information Technology Co ltd
Current assignee: Wuhan Shiju Information Technology Co ltd
Priority date: 2022-10-14
Filing date: 2022-10-14
Publication date: 2022-11-11
Anticipated expiration: 2042-10-14
Also published as: CN115334609B

Abstract

The application discloses a channel switching method and device of a mobile terminal. Aiming at the problem of large channel switching delay when multiple candidate target base stations exist, the following technical scheme is provided, a source base station sends switching channel request information containing candidate target base station information to a core network; the core network forwards the request information of the switching channel to the candidate target base station; the candidate target base station sends channel switching request acknowledgement information to the source base station; the source base station generates RRC reconfiguration information according to the switching channel request admission information; the source base station sends the RRC reconfiguration information to the terminal; the terminal sends RRC reconfiguration completion information to the candidate target base station; the source base station judges whether the number of the candidate target base stations meets the forwarding condition or not; and when the forwarding condition is met, the source base station sends channel switching request information to the core network. The core network with stronger performance replaces the source base station, and the channel switching request information is forwarded to the candidate target base stations one by one, so that the load of the source base station is reduced, and the channel switching delay is shortened.

Description

Channel switching method and device of mobile terminal

Technical Field

The present application relates to the field of wireless communication technologies, and in particular, to a method and an apparatus for channel switching of a mobile terminal.

Background

The R16 version of the third Generation Partnership project (3 rd Generation Partnership project,3 gpp) is a new channel switching procedure introduced for 5G communications. The new channel switching process is called Conditional Handover (CHO), and the specific implementation process is that the source base station configures a plurality of Conditional switching commands according to a plurality of candidate target base station information reported by a terminal (User Equipment, UE) and respectively sends the Conditional switching commands to a plurality of candidate target base stations; after receiving the responses of the candidate target base stations, the source base station sends a conditional switching command containing the information of the candidate target base stations to the terminal; the terminal selects a target base station meeting the switching execution condition from a plurality of candidate target base stations according to the information of the candidate target base stations in the conditional switching command; and the terminal initiates random access to the target base station and finally completes the switching process.

In the process that the source base station configures the conditional handover command for the terminal, the source base station needs to respectively package and encode information of a plurality of candidate target base stations to generate handover request messages of each candidate target base station, and then respectively send the plurality of handover request messages to the plurality of candidate target base stations.

In the process of implementing the prior art, the inventor finds that:

the source base station in the channel switching process generates the switching request message of each candidate target base station and sends each switching request message to each candidate target base station one by one, thereby greatly increasing the workload of the source base station and greatly increasing the time delay of channel switching.

Disclosure of Invention

In view of the deficiencies of the prior art, a first object of the present application is to provide a channel switching method for a mobile terminal, in which a core network receives a channel switching request message including information of a candidate target base station, and the core network forwards the channel switching request message to the candidate target base station respectively. The core network forwards the channel switching request information, so that the working load of the source base station is reduced, and the time delay is reduced.

In order to achieve the purpose, the application provides the following technical scheme:

a channel switching method of a mobile terminal includes the following steps:

a source base station sends switching channel request information containing candidate target base station information to a core network;

the core network forwards the switching channel request information to the candidate target base station according to the candidate target base station information so as to replace the source base station through the core network, thereby reducing the load of the source base station;

the candidate target base station sends channel switching request acknowledgement information to the source base station;

the source base station generates RRC reconfiguration information containing candidate target base station information according to all the switching channel request acknowledgement information;

the source base station sends RRC reconfiguration information containing the information of the candidate target base station to the terminal;

the terminal sends RRC reconfiguration completion information to the candidate target base station to complete channel switching;

the source base station selects a candidate target base station according to a measurement report reported by the terminal and a local switching strategy;

the source base station judges whether the number of the candidate target base stations meets the forwarding condition;

when the forwarding condition is satisfied, the source base station sends a message containing the candidate target base station to the core network through the NG interface

Information of the handover channel request information.

Further, the candidate target base station sends the channel switching request acknowledgement information to the source base station, and the method specifically comprises the following steps:

the candidate target base station acquires the position information of the source base station according to the switching channel request information;

the candidate target base station selects an Xn link according to the position information of the source base station so as to establish communication connection between the candidate target base station and the source base station;

through the Xn link, the candidate target base station sends switching channel request acknowledgement information to the source base station.

Further, the terminal sends RRC reconfiguration complete information to the candidate target base station to complete channel switching, which specifically includes the following steps:

the terminal acquires the information of the candidate target base station according to the RRC reconfiguration information;

the terminal evaluates whether the candidate target base station meets the channel switching triggering condition or not according to the information of the candidate target base station;

when the candidate target base station meets the channel switching triggering condition, the terminal sends RRC reconfiguration completion information to the candidate target base station;

and the candidate target base station sends switching success information to the source base station so as to indicate that channel switching is completed to the source base station.

Further, the method also comprises the following steps:

when the candidate target base station receives the RRC reconfiguration completion information, the candidate target base station sends path switching request information to the core network so as to indicate the core network that the terminal has established connection with the candidate target base station;

the core network sends data forwarding end information to the source base station according to the path switching request information;

the core network sends path switching request acknowledge information to the candidate target base station so that the core network replaces the source base station and is connected with the candidate target base station.

Further, the method also comprises the following steps:

the candidate target base station judges whether the terminal meets the admission condition or not according to the switching channel request information;

and when the terminal meets the admission condition, the candidate target base station configures channel switching resources for the terminal according to the channel switching request information so as to prepare the candidate target base station for establishing communication connection with the terminal.

In view of the deficiencies of the prior art, a second object of the present application is to provide a channel switching apparatus for a mobile terminal, which has the advantages of reducing the workload of a source base station, and thus reducing the time delay for switching channels.

In order to achieve the above purpose, the present application provides the following technical solutions:

a channel switching apparatus of a mobile terminal, comprising:

the switching channel request information acquisition unit is arranged on the source base station, is in communication connection with the core network, and is used for sending switching channel request information containing candidate target base station information to the core network;

the switching channel request information forwarding unit is arranged in the core network, is in communication connection with the candidate target base station, and is used for forwarding the switching channel request information to the candidate target base station so as to replace the source base station through the core network, thereby reducing the load of the source base station;

a switching channel request acknowledgement information sending unit, which is arranged at the candidate target base station, is in communication connection with the switching channel request information forwarding unit, and is used for sending switching channel request acknowledgement information to the source base station;

an RRC reconfiguration information generating unit, provided in the source base station, communicatively connected to the handover channel request grant information transmitting unit, for generating RRC reconfiguration information including information of the candidate target base station;

the RRC reconfiguration information sending unit is arranged on the source base station, is in communication connection with the RRC reconfiguration information generating unit and is used for sending the RRC reconfiguration information containing the candidate target base station information to the terminal;

the RRC reconfiguration completion information sending unit is arranged at the terminal, is in communication connection with the RRC reconfiguration information sending unit, and is used for sending RRC reconfiguration completion information to the candidate target base station to complete channel switching;

a candidate target base station selection unit arranged in the source base station and used for selecting a candidate target base station according to the measurement report reported by the terminal

Informing a local handover strategy, selecting a candidate target base station, said candidate target base station selection unit and a handover signalling

The channel request information acquisition unit is in communication connection and is provided with an NG interface,

the switching channel request information acquisition unit is in communication connection with a core network through an NG interface; the source base station also

And the method is used for judging whether the number of the candidate target base stations meets the forwarding condition.

Further, still include:

a source base station position information obtaining unit, which is arranged in the candidate target base station, is in communication connection with the switching channel request information obtaining unit, and is used for obtaining the position information of the source base station;

and the link establishing unit is arranged in the candidate target base station, is in communication connection with the source base station position information acquiring unit and the switching channel request acknowledgement information sending unit, is used for selecting the Xn link, and sends the switching channel request acknowledgement information to the source base station.

In summary, the present application has the following beneficial effects:

under the condition that a plurality of candidate target base stations exist, the core network is used for replacing the source base station, and a plurality of channel switching requests are respectively forwarded to the candidate target base stations, so that the working load of the source base station is reduced, and the time delay of channel switching is reduced. The performance of the core network for processing information is higher than that of the source base station, so that the time delay of channel switching is further reduced. Under the condition that only one candidate target base station exists, the source base station directly sends the switching channel request information to the candidate target base station without core network forwarding, the load of a base station system is reduced, and the system is simplified.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

fig. 1 is a schematic diagram illustrating steps of a channel switching method of a mobile terminal.

Fig. 2 is a schematic diagram illustrating a specific step of the candidate target base station in fig. 1 sending a channel switching request acknowledgement message to the source base station.

Fig. 3 is a schematic diagram illustrating specific steps of the terminal in fig. 1 sending RRC reconfiguration complete information to a candidate target base station.

Fig. 4 is a schematic diagram illustrating the steps of the channel switching method of the mobile terminal.

Fig. 5 is a schematic diagram illustrating the steps of the channel switching method of the mobile terminal.

Fig. 6 is a schematic structural diagram of a channel switching apparatus of a mobile terminal.

Fig. 7 is a general flowchart of a channel switching method of a mobile terminal.

100. Channel switching device of mobile terminal

11. Switching channel request information acquisition unit

12. Switching channel request information forwarding unit

13. Channel switching request acknowledgement information transmitting unit

14 RRC reconfiguration information generation unit

15 RRC reconfiguration information transmitting unit

16 RRC reconfiguration complete information transmitting unit

17. Candidate target base station selection unit

18. Source base station position information acquisition unit

19. A link establishment unit.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, the technical solutions of the present application will be clearly and completely described below with reference to specific embodiments of the present application and the accompanying drawings. It should be apparent that the described embodiments are only a few embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The present application provides a channel switching method of a mobile terminal, referring to fig. 1, including the following steps:

s100: and the source base station sends switching channel request information containing the information of the candidate target base station to the core network.

In this application, the source base station is a base station to which the terminal is currently in data connection. The candidate target base station is the base station to which the terminal is about to prepare a data connection. There are a plurality of candidate target base stations. The candidate target base station information comprises candidate target base station identification information and cell information of the candidate target base station. The core network (AMF) is responsible for processing and distributing data of the bearer network and the Access network. The core network acts as the "management hub" of the communication network. Compared with the base station, the core network has much higher data processing capability than the base station. The handover channel request information is information that the source base station transmits to the candidate target base stations. The switching channel request information is information that the terminal requests to establish a data connection with the candidate target base station. The handover channel request information includes candidate target base station information, cell information of a candidate target base station, cell-Radio Network Temporary Identifier (C-RNTI) of a source base station Cell, radio Resource Management (RRM) of the terminal, and measurement information reported by the terminal.

S200: and the core network forwards the switching channel request information to the candidate target base station according to the candidate target base station information so as to replace the source base station through the core network, thereby reducing the load of the source base station.

In the present application, there are a plurality of candidate target base stations. The candidate target base station information is summary information including an identification of each candidate target base station. The candidate target base station information is specifically a list comprising a plurality of candidate target base station identities. According to the specification of the 3GPP protocol, the candidate target base station information may include up to 8 candidate target base station identification information.

Specifically, the handover channel request message specifically includes a "Source NG-RAN Node to Target NG-RAN Node Transparent Container" information element from the 5G access network of the Source base station to the 5G access network of the Target base station. Cells are the basic unit of Asynchronous Transfer Mode (ATM) switching and multiplexing. The "transparent container of 5G access network of source base station to 5G access network of Target base station" Cell includes a list (Target Cell ID) listing Cell information of a plurality of candidate Target base stations and a list (Target Gnb ID) listing identification information of a plurality of candidate Target base stations.

It is understood that, in the 3GPP protocol, the "transparent container of 5G access network of source base station to 5G access network of Target base station" Cell includes Cell information (Target Cell ID) where a single Target base station is located and single Target base station identification information (Target Gnb ID). In the prior art, when a source base station sends a request message for switching channels to a plurality of candidate target base stations, it is necessary to first perform packet packing and encoding on the information of the candidate target base stations, generate request messages for switching channels of each candidate target base station, and finally send the request messages for switching channels to each candidate target base station one by one.

In the present application, a piece of cell information of a single target base station is replaced with a list of cell information of multiple candidate target base stations, and a piece of identification information of the single target base station is replaced with identification information of base stations of multiple candidate target cells. The source base station only needs to send a piece of switching channel request information to the core network, and then the core network forwards the switching channel request information to a plurality of candidate target base stations. There is no need for the source base station to send multiple handover channel request messages to multiple candidate target base stations, respectively. That is to say, the core network replaces the source base station in the work of sending the channel switching request information to the candidate target base stations, so that the work load of the source base station is reduced, the source base station can process the next work more quickly, and the time delay of channel switching is reduced. In addition, because the capability of processing data of the core network is higher than that of the source base station, the core network can forward the information to the candidate target base stations faster than the case that the source base station directly sends the information to the candidate target base stations, and the time delay of channel switching is further reduced.

S300: the candidate target base station sends handover channel request acknowledge information to the source base station.

In this application, the handover channel request acknowledgement information is information sent by the candidate target base station to the source base station, so as to indicate that the candidate target base station has received the handover channel request forwarded by the core network. The channel switching request acknowledge information comprises the candidate target base station allocating channel switching resources for the terminal so as to indicate to the source base station that the candidate target base station is ready for channel switching. That is, the candidate target base station indicates to the source base station that the candidate target base station is ready to establish a data connection with the terminal, so that the source base station is ready to send RRC reconfiguration information to the terminal.

Further, referring to fig. 2, step S300 specifically includes the following steps:

s301: and the candidate target base station acquires the position information of the source base station according to the switching channel request information.

S302: and the candidate target base station selects the Xn link according to the position information of the source base station so as to enable the candidate target base station to establish communication connection with the source base station.

S303: through the Xn link, the candidate target base station sends switching channel request acknowledgement information to the source base station.

In the present application, the channel switching request Information further includes terminal History Information (UE History Information). The terminal history information includes location information of the source base station. The location information of the source base station is specifically the location of the cell in which the source base station is located. The Xn link is a path for establishing a data connection between the base station and the base station. The Xn link is a line connected to an Xn interface provided in each base station.

Specifically, the candidate target base station searches the position information of the source base station through the terminal history information, then the candidate target base station searches the corresponding Xn link according to the position information of the source base station, the candidate target base station establishes communication connection with the source base station according to the Xn link, and finally the candidate target base station sends channel switching request acknowledgement information to the source base station through the Xn link.

It can be understood that, when the link between the source base station and the candidate target base station is stably connected, the source base station can establish a stable connection with the candidate target base station to ensure smooth information transmission, so that the candidate target base station can receive the channel switching request information. Through the Xn link which is used for stably communicating data between the source base station and the target base station, the source base station can send the switching channel request information to the candidate target base station, and the candidate target base station can send the switching channel request acknowledgement information to the source base station, so that the stable operation of the communication system is ensured.

S400: the source base station generates RRC reconfiguration information including information of the candidate target base stations based on all the handover channel request acknowledgement information.

In the present application, the handover channel request grant information received by the source base station is sent by each candidate target base station. The RRC reconfiguration information includes a plurality of candidate target base station information. The RRC reconfiguration information specifically includes a list (Target Cell ID) in which Cell information of a plurality of candidate Target base stations are listed and a list (Target Gnb ID) in which identification information of a plurality of candidate Target base stations is listed.

Specifically, the handover channel request acknowledgement information includes information that the candidate target base station allocates channel handover resources for the terminal and the candidate target base station. When the source base station receives the multiple switching channel request acknowledge information, extracting candidate target base stations in the switching channel request acknowledge information to allocate channel switching resources for the terminal, cell information of the multiple candidate target base stations and the identification information of the multiple candidate target base stations, and assembling the multiple candidate target base stations to allocate channel switching resources for the terminal and the multiple candidate target base station information into a complete RRC reconfiguration information.

It can be understood that the source base station only needs to send one piece of RRC reconfiguration information, so that the terminal can simultaneously receive information of multiple candidate target base stations and allocate channel switching resources to the terminal by the multiple candidate target base stations. Compared with the mode that each piece of candidate target base station information is assembled with one piece of RRC reconfiguration information, the source base station sends a plurality of pieces of RRC reconfiguration information to the terminal one by one, the source base station only needs to send one piece of RRC reconfiguration information, the terminal can receive all pieces of candidate target base station information, the workload of the source base station is reduced, the data processing speed of the source base station is higher, and the channel switching time delay is reduced.

S500: and the source base station transmits the RRC reconfiguration information containing the candidate target base station information to the terminal.

In the present application, the terminal is a mobile terminal. The terminal can be a mobile phone, a notebook computer, a tablet computer and a vehicle-mounted computer. And the terminal acquires the information of the candidate target base stations and the channel switching resources distributed to the terminal by the candidate target base stations according to the RRC reconfiguration information.

It can be understood that, when the RRC reconfiguration message is sent to the terminal, the terminal receives the channel switching resources allocated to the terminal by the multiple candidate target base stations, so as to indicate to the terminal that the candidate target base stations are ready to establish a data connection with the terminal, so that the terminal is ready to select one target base station from the multiple candidate target base stations for channel switching.

S600: and the terminal sends RRC reconfiguration completion information to the candidate target base station to complete channel switching.

In this application, the RRC Reconfiguration Complete message (RRC Reconfiguration Complete) is a message that the terminal sends to a selected candidate target base station of the plurality of candidate target base stations, so as to notify the selected candidate target base station that the terminal is ready to establish a data connection with the source base station. The rest of the other candidate target base stations do not receive the RRC reconfiguration complete message.

Further, referring to fig. 3, step S600 specifically includes the following steps:

s601: and the terminal acquires the information of the candidate target base station according to the RRC reconfiguration information.

S602: and the terminal evaluates whether the candidate target base station meets the channel switching triggering condition or not according to the information of the candidate target base station.

S603: and when the candidate target base station meets the channel switching triggering condition, the terminal sends RRC reconfiguration completion information to the candidate target base station.

S604: and the candidate target base station sends switching success information to the source base station so as to indicate the completion of channel switching to the source base station.

In the present application, the RRC reconfiguration complete information is a response to the RRC reconfiguration information from the terminal to the selected candidate target base station, so as to prompt the selected candidate target base station to prepare for connecting with the terminal. The channel switching triggering condition is used for judging which candidate target base station provides the best channel quality for the terminal from a plurality of candidate target base stations. The best channel quality is judged according to which candidate target base station is the best channel switching resource configured for the terminal and which candidate target base station is closest to the terminal.

Specifically, after the terminal selects one candidate target base station from the multiple candidate target base stations, the terminal sends RRC reconfiguration complete information to the selected candidate target base station. And after the selected candidate target base station receives the RRC reconfiguration completion information, the selected candidate target base station sends Handover Success information (Handover Success) to the source base station to inform the source base station that the channel of the terminal is already handed over to one side of the selected candidate target base station. And providing the communication service for the terminal by the candidate target base station instead of the source base station, and prompting the source base station to release the data connection with the terminal.

It can be understood that, the terminal may obtain the location information of the multiple candidate target base stations and the channel switching resource configured for the terminal by the multiple candidate target base stations through one piece of RRC reconfiguration information. Compared with the mode that the terminal receives a plurality of pieces of RRC reconfiguration information to obtain the position information of the candidate target base station and the channel switching resources configured for the terminal, the scheme reduces the pressure of the terminal on data processing. And comparing the information of the candidate target base stations by setting a channel switching trigger condition to determine the optimal candidate target base station. Compared with a mode of randomly selecting a candidate target base station, the scheme enables the terminal to receive the optimal channel connection and enables the user to experience the optimal communication service.

S700: and the source base station selects a candidate target base station according to the measurement report reported by the terminal and the local switching strategy.

In the present application, the contents of the measurement report are the position of the terminal, the moving speed of the terminal, and the moving direction of the terminal. The local switching strategy is a method for configuring a channel for the terminal by the base station according to the service requirement and the transmission channel quality of the terminal. The candidate target base station is a base station that conforms to the measurement report and the local handover policy among a plurality of base stations adjacent to the source base station.

S800: and the source base station judges whether the number of the candidate target base stations meets the forwarding condition.

S900: and when the forwarding condition is met, the source base station sends switching channel request information containing the information of the candidate target base station to the core network through the NG interface.

In this application, the specific content of the forwarding condition is that the number of candidate target base stations is greater than or equal to 2. The NG interface is the interface between the 5G radio access network and the core network. That is, the NG interface is an interface connecting the source base station and the candidate target base station with the core network. A data connection is established between the source base station and the core network via the NG interface. The NG interface can not only interconnect the 5G wireless access network with core networks provided by different manufacturers, but also separate the wireless network function and the transmission network function of the NG interface, so as to introduce a novel technology.

And establishing a connection path for data transmission between the source base station and the candidate target base station and the core network through the NG interface. The source base station sends the switching channel request information sent by the terminal to the source base station to the core network through the NG interface. The core network sends the channel switching request to the candidate target base station so that the candidate target base station configures channel switching resources for the terminal.

It can be understood that, the source base station selects a suitable candidate target base station near the source base station according to the location distribution, the moving speed, the moving direction, the service requirement and the transmission channel quality of the terminal, so as to reduce the channel switching delay caused by the mismatching of the terminal and the candidate target base station, thereby ensuring that the terminal obtains a good communication service. When the link interface of the source base station is matched with the link interface of the core network, the source base station can establish connection with the core network. That is, the source base station and the core network establish communication connection through the NG interface, so that the core network can receive the channel switching request information, and smooth information transmission is ensured.

Specifically, when the number of candidate target base stations is greater than or equal to 2, the source base station transmits handover channel request information including information of the candidate target base stations to the core network through the NG interface. When the number of candidate target base stations is equal to 1, the source base station directly transmits handover channel request information to the candidate target base stations.

It can be understood that the source base station determines whether the number of candidate target base stations satisfies the forwarding condition according to the candidate target information. That is, the source base station determines whether there are at least two candidate target base stations. When there are at least two candidate target base stations, the source base station needs to package the information packets of the multiple candidate target base stations into the switching channel request information, and forward the switching channel request information to the core network, so that the core network forwards the switching channel request information to the multiple candidate target base stations. When only one candidate target base station exists, the source base station combines the information of the single candidate target base station into the switching channel request information and directly sends the switching channel request information to the candidate target base station. And adding a judgment step, wherein the source base station does not forward all information of the channel switching request to the core network. In the case of only one candidate target base station, the source base station directly transmits a handover channel request message to one candidate target base station. The method only needs to send one piece of switching channel request information, the workload of the source base station is not heavy, and the source base station does not need to forward to the candidate target base station through the core network, so that the resource occupation of the core network is reduced, the workload of the core network is reduced, and the operation of the base station system is simplified.

Further, referring to fig. 4, the method further includes the following steps:

s1100: when the candidate target base station receives the RRC reconfiguration completion information, the candidate target base station sends path switching request information to the core network so as to indicate to the core network that the terminal has established connection with the candidate target base station.

In the present application, the Path Switch Request message (Path Switch Request) is sent by the candidate target base station to the core network. The content of the path switching request information requests the core network to switch the path of the data connection from the source base station side to the candidate target base station side selected by the terminal. And the core network is in data connection with both the source base station and the candidate target base station.

S1200: and the core network sends data forwarding end information to the source base station according to the path switching request information.

In the present application, the End Marker (End Marker) is sent by the core network to the source base station. The content of the data transfer end information is to notify the source base station to stop transmitting data to the terminal.

S1300: the core network sends path switching request acknowledge information to the candidate target base station so that the core network replaces the source base station and is connected with the candidate target base station.

In the present application, the Path Switch Request acknowledgement (Path Switch Request acknowledgement) is information that the core network responds to the candidate target base station. The content of the path switching request acknowledge information is that the core network has directly established data connection with the terminal, and the data does not need to be forwarded to the terminal through the source base station.

It can be understood that after the candidate target base station establishes the data connection with the terminal, the terminal still maintains the data connection with the source base station, and the terminal is simultaneously in data connection with the candidate target base station and the source base station. The core network is used for replacing the source base station to keep data connection with the terminal, so that the source base station can stop transmitting data to the terminal conveniently, the workload of the source base station is reduced on one hand, and good communication service of the terminal is guaranteed on the other hand.

Further, referring to fig. 5, the method further includes the following steps:

s130: and the candidate target base station judges whether the terminal meets the admission condition or not according to the switching channel request information.

In the present application, an admission condition is a condition in which a candidate target base station grants a terminal access. The specific content of the admission condition is whether the load condition of the candidate target base station can accept the access of the terminal. When the candidate target base station receives the terminal access request, the candidate target base station judges whether the load of providing the communication service for the terminal can be borne or not according to the load condition of the candidate target base station.

S140: and when the terminal meets the admission condition, the candidate target base station configures channel switching resources for the terminal according to the channel switching request information so as to prepare the candidate target base station for establishing communication connection with the terminal.

In the present application, when the load condition of the candidate target base station can bear the load of providing service for the terminal, the candidate target base station is ready to access the terminal. When the load condition of the candidate target base station can not accept the new access request, the candidate target base station refuses to be connected with the terminal so as to ensure the stable work of the candidate target base station, avoid the overload of the candidate target base station and ensure the optimal communication service of the terminal.

Specifically, when the terminal satisfies the admission condition, the candidate target base station sends context establishment request information including admission success information to the terminal to indicate to the terminal to accept the access of the terminal. The terminal feeds back the context establishment response information to the candidate target base station to indicate the candidate target base station that the terminal is ready to be connected with the candidate target base station. At this time, the candidate target base station already establishes context connection with the terminal, and the candidate target base station configures channel switching resources for the terminal and sends the channel switching resources to the terminal.

It can be understood that, before receiving the access of the terminal, the candidate target base station evaluates whether the candidate target base station can provide the communication service for the terminal according to the current load condition of the candidate target base station. And when the load of the candidate target base station can not provide communication service for the newly added terminal any more, the candidate target base station refuses the access of the newly added terminal. That is, to ensure that the base station is not overloaded, the candidate target base station first evaluates its own load condition and then determines whether to grant the terminal access. Similarly, the purpose of adding the admission judgment step is to ensure the normal work of the candidate target base station, so that the candidate target base station system does not crash, and the stability of the system operation is improved. Meanwhile, the candidate target base station is ensured to provide communication service for the terminal, and the interruption of the terminal communication service caused by the mismatching of the candidate target base station and the terminal is avoided, so that the system is more reliable in operation.

The technical scheme is not only suitable for the channel switching based on the CHO, but also suitable for the channel switching of the switching process of other multi-candidate target cells, increases the application range and ensures compatibility.

Referring to fig. 7, the method further comprises the following steps:

when the source base station receives the switching channel request acknowledgement information sent by a plurality of candidate target base stations, the source base station sends early state forwarding information to the first target base station to forward a downlink data packet in advance, so that the first target base station reserves conditional switching resources for the terminal.

And the terminal randomly accesses the second target base station according to the switching channel request information containing the information of the candidate target base stations.

And the second target base station sends the switching success information to the source base station.

And the source base station sends switching cancellation information to the first target base station according to the switching success information so as to inform the first target base station to release the reserved conditional switching resources.

Specifically, the source base station randomly selects one candidate target base station, i.e., the first target base station. The source base station sends early state forwarding information to the first target base station so that the source base station forwards a downlink data packet to the first target base station in advance.

The terminal monitors and evaluates the measurement result of each candidate target base station according to the switching channel request information containing the information of a plurality of candidate target base stations, and when the second target base station meets the CHO triggering condition, the terminal initiates random access.

And after the terminal finishes random access, the terminal sends RRC reconfiguration completion information to the second candidate base station, at the moment, uplink data are sent to the second target base station, and the downlink data are continuously sent to the source base station.

And the second target base station sends switching success information to the source base station to inform the source base station that the terminal is switched to the second target base station.

The source base station transmits SN state transition information to the second target base station, the SN state transition information including PDCP SN information and HFN information.

And the source base station forwards the downlink data from the first target base station to a second target base station, and the second target base station sends the downlink data from the first target base station to the terminal according to the PDCP SN and the HFN information.

And the second target base station receives the uplink data from the terminal according to the PDCP SN information and the HFN information.

And the second target base station sends the uplink data to the core network.

And after receiving the switching success information sent by the second target base station, the source base station sends switching cancellation information to the first target base station to inform the first target base station to release the reserved conditional switching resource.

It can be understood that, according to the information of multiple candidate target base stations, the source base station randomly selects one target base station for connection, that is, the source base station is connected with the first target base station to serve as a candidate for the case that the connection between the terminal and the second target base station selected by the terminal fails, so as to reduce the probability of channel switching failure and ensure that the terminal continuously obtains communication service in the channel switching process. The first target base station receives the early state forwarding information, and indicates that the first target base station is ready to establish data connection with the terminal. And the second target base station receives the RRC reconfiguration complete message, and the RRC reconfiguration complete message indicates that the terminal and the second target base station complete synchronization and random access.

The present application further provides a channel switching apparatus 100 of a mobile terminal, which is adapted to a channel switching method of a mobile terminal, and referring to fig. 6, the method includes:

a switching channel request information obtaining unit 11, disposed in the source base station, communicatively connected to the core network, and configured to send switching channel request information including information of the candidate target base station to the core network;

a switching channel request information forwarding unit 12, disposed in the core network, communicatively connected to the candidate target base station, and configured to forward the switching channel request information to the candidate target base station, so as to replace the source base station with the core network, thereby reducing a load of the source base station;

a switching channel request grant information sending unit 13, disposed at the candidate target base station, connected to the switching channel request information forwarding unit 12 in a communication manner, and configured to send switching channel request grant information to the source base station;

an RRC reconfiguration information generating unit 14, provided in the source base station, communicatively connected to the handover channel request grant information transmitting unit 13, for generating RRC reconfiguration information including information of the candidate target base station;

an RRC reconfiguration information transmitting unit 15, provided in the source base station, communicatively connected to the RRC reconfiguration information generating unit 14, and configured to transmit RRC reconfiguration information including information of the candidate target base station to the terminal;

an RRC reconfiguration complete information sending unit 16, configured to the terminal, and in communication with the RRC reconfiguration information sending unit 15, configured to send RRC reconfiguration complete information to the candidate target base station, so as to complete channel switching;

a candidate target base station selecting unit 17, which is arranged in the source base station and is used for selecting a candidate target base station according to a measurement report reported by a terminal and a local switching strategy, wherein the candidate target base station selecting unit 17 is in communication connection with a switching channel request information obtaining unit, the switching channel request information obtaining unit is provided with an NG interface, and the switching channel request information obtaining unit is in communication connection with a core network through the NG interface; the source base station is further configured to determine whether the number of candidate target base stations satisfies a forwarding condition.

In this application, the source base station is a base station to which the terminal is currently in data connection. The candidate target base station is the base station to which the terminal is to prepare a data connection. There are a plurality of candidate target base stations. The candidate target base station information comprises candidate target base station identification and cell information of the candidate target base station. The core network (AMF) is responsible for processing and distributing data of the bearer network and the Access network. The core network acts as the "management hub" of the communication network. Compared with the base station, the core network has much higher data processing capability than the base station. The handover channel request information is information that the source base station transmits to the candidate target base stations. The handover channel request message is a message that the terminal requests to establish a data connection with the candidate target base station. The channel switching request information includes candidate target base station information, cell information of the candidate target base station, a Cell-Radio Network Temporary Identifier (C-RNTI) of the source base station Cell, radio Resource Management (RRM) configuration of the terminal, and measurement information reported by the terminal.

The candidate target base station information is summary information including an identification of each candidate target base station. The candidate target base station information is specifically a list comprising a plurality of candidate target base station identities. According to the specification of the 3GPP protocol, the information of the candidate target base stations may include at most 8 candidate target base station identifiers. Specifically, the handover channel request message includes a "Source NG-RAN Node to Target NG-RAN Node Transparent Container" information element from the 5G access network of the Source base station to the 5G access network of the Target base station. The "transparent container of 5G access network of source base station to 5G access network of Target base station" Cell includes a list (Target Cell ID) listing Cell information of a plurality of candidate Target base stations and a list (Target Gnb ID) listing identification information of a plurality of candidate Target base stations.

Specifically, the switching channel request information obtaining unit 11 is disposed in the source base station and is in communication connection with the source base station. The switching channel request information obtaining unit 11 is also in communication connection with the core network. The handover channel request information obtaining unit 11 sends handover channel request information including information of the candidate target base station to the core network, so that the core network makes preparations for forwarding the handover channel request information to the candidate target base station.

The core network is communicatively connected with a switching channel request information forwarding unit 12. The handover channel request information forwarding unit 12 is communicatively connected to the candidate target base station. The handover channel request information forwarding unit 12 forwards the handover channel request information to the candidate target base station, so that the core network prepares to forward the handover channel request information to the candidate target base station.

It is understood that, in the 3GPP protocol, the "transparent container of 5G access network of source base station to 5G access network of Target base station" Cell includes Cell information (Target Cell ID) where a single Target base station is located and single Target base station identification information (Target Gnb ID). In the application, the cell information of a single target base station is changed into a list with the cell information of a plurality of candidate target base stations, and the identification information of the single target base station is changed into the identification information of the base stations of the candidate target base stations. The source base station only needs to send a piece of switching channel request information to the core network, and then the core network forwards the switching channel request information to a plurality of candidate target base stations. There is no need for the source base station to send multiple handover channel request messages to multiple candidate target base stations, respectively. That is to say, the core network replaces the source base station in the work of sending the channel switching request information to the candidate target base stations, so that the work load of the source base station is reduced, the source base station can process the next work more quickly, and the time delay of channel switching is reduced. In addition, because the capability of processing data of the core network is higher than that of the source base station, the core network can forward the information to the candidate target base stations faster than the case that the source base station directly sends the information to the candidate target base stations, and the time delay of channel switching is further reduced.

In this application, the handover channel request acknowledge information is information sent by the candidate target base station to the source base station to indicate that the candidate target base station has received the handover channel request forwarded by the core network. The channel switching request acknowledge information comprises the candidate target base station allocating channel switching resources for the terminal so as to indicate to the source base station that the candidate target base station is ready for channel switching. That is, the candidate target base station indicates to the source base station that the candidate target base station is ready to establish a data connection with the terminal, so that the source base station is ready to send RRC reconfiguration information to the terminal. The source base station receives the switching channel request acknowledge information which is sent by each candidate target base station. The RRC reconfiguration information includes a plurality of candidate target base station information. The RRC reconfiguration information specifically includes a list (Target Cell ID) in which Cell information of a plurality of candidate Target base stations are listed and a list (Target Gnb ID) in which identification information of a plurality of candidate Target base stations is listed. Specifically, the handover channel request grant information includes information that the candidate target base station allocates channel handover resources for the terminal and the candidate target base station. When the source base station receives the multiple switching channel request acknowledge information, extracting candidate target base stations in the switching channel request acknowledge information to allocate channel switching resources for the terminal, cell information of the multiple candidate target base stations and the identification information of the multiple candidate target base stations, and assembling the multiple candidate target base stations to allocate channel switching resources for the terminal and the multiple candidate target base station information into a complete RRC reconfiguration information.

Specifically, the handover channel request acknowledgement information transmitting unit 13 is communicatively connected to each of the plurality of candidate target base stations. The plurality of switch channel request acceptance information sending units 13 are each communicatively connected to one switch channel request information transfer unit 12. The switching channel request acknowledge information transmission unit 13 transmits switching channel request acknowledge information to the source base station to prepare the source base station for generating RRC reconfiguration information.

Specifically, the source base station is connected to the RRC reconfiguration information generation unit 14 in communication. The RRC reconfiguration information generation unit 14 is in communication connection with the switching channel request acknowledgment information transmission unit 13. The RRC reconfiguration information generation unit 14 generates RRC reconfiguration information including candidate target base station information in preparation for transmitting the RRC reconfiguration information to the terminal.

Specifically, the source base station is connected to the RRC reconfiguration information transmitting unit 15 in communication. The RRC reconfiguration information transmitter 15 is in communication with the RRC reconfiguration information generator 14, and the RRC reconfiguration information transmitter 15 transmits RRC reconfiguration information including information of the candidate target base station to the terminal so that the terminal is ready to generate RRC reconfiguration complete information. The terminal is connected to an RRC reconfiguration complete information transmitting unit 16. The RRC reconfiguration complete information transmitting unit 16 is in communication connection with the RRC reconfiguration information transmitting unit 15. The RRC reconfiguration complete information sending unit 16 sends RRC reconfiguration complete information to the candidate target base station, and completes channel switching.

It can be understood that, the terminal may obtain the location information of the multiple candidate target base stations and the channel switching resources configured for the terminal by the multiple candidate target base stations through one piece of RRC reconfiguration information. Compared with the mode that the terminal receives a plurality of pieces of RRC reconfiguration information to obtain the position information of the candidate target base station and the channel switching resources configured for the terminal, the scheme reduces the pressure of the terminal on data processing.

In the present application, the contents of the measurement report are the position of the terminal, the moving speed of the terminal, and the moving direction of the terminal. The local switching strategy is a method for configuring a channel for a terminal by a base station according to the service requirement and the transmission channel quality of the terminal. The candidate target base station is a base station that conforms to the measurement report and the local handover policy among a plurality of base stations adjacent to the source base station. The NG interface is the interface between the 5G radio access network and the core network. That is, the NG interface is an interface between the connection source base station and the candidate target base station and the core network. A data connection is established between the source base station and the core network via the NG interface. The NG interface can not only interconnect the 5G wireless access network with core networks provided by different manufacturers, but also separate the wireless network function and the transmission network function of the NG interface, so as to introduce a novel technology. And establishing a connection path for data transmission between the source base station and the candidate target base station and the core network through the NG interface. The source base station sends the switching channel request information sent by the terminal to the source base station to the core network through the NG interface. And the core network sends the channel switching request to the candidate target base station so that the candidate target base station configures channel switching resources for the terminal.

It can be understood that the source base station selects an appropriate candidate target base station near the source base station according to the location distribution, the moving speed, the moving direction, the service requirement and the transmission channel quality of the terminal, so as to reduce the time delay of channel switching caused by mismatching between the terminal and the candidate target base station, thereby ensuring that the terminal obtains a good communication service. When the link interface of the source base station is matched with the link interface of the core network, the source base station can establish connection with the core network. That is, the source base station and the core network establish communication connection through the NG interface, so that the core network can receive the channel switching request information, and smooth information transmission is ensured.

Further, still include:

a source base station location information obtaining unit 18, which is arranged in the candidate target base station, is in communication connection with the switching channel request information obtaining unit 11, and is used for obtaining location information of the source base station;

and a link establishing unit 19, which is disposed at the candidate target base station, is in communication connection with the source base station position information acquiring unit 18 and the switching channel request acknowledgment information transmitting unit 13, and is configured to select the Xn link and transmit the switching channel request acknowledgment information to the source base station.

In the present application, the channel switching request Information further includes terminal History Information (UE History Information). The terminal history information includes location information of the source base station. The location information of the source base station is specifically the location of the cell in which the source base station is located. The Xn link is a path for establishing a data connection between the base station and the base station. The Xn link is a line connected to an Xn interface provided in each base station. Specifically, the candidate target base station searches the position information of the source base station through the terminal history information, then the candidate target base station searches the corresponding Xn link according to the position information of the source base station, the candidate target base station establishes communication connection with the source base station according to the Xn link, and finally the candidate target base station sends channel switching request acknowledgement information to the source base station through the Xn link.

Specifically, the candidate target base station is also communicatively connected to the active base station location information acquisition unit 18. The source base station location information acquisition unit 18 is communicatively connected to the switching channel request information acquisition unit 11. The source base station position information acquisition unit 18 acquires position information of the source base station. The candidate target base station is also communicatively connected with a link establishment unit 19. The link establishing unit 19 is communicatively connected to both the source base station position information acquiring unit 18 and the switching channel request acknowledgement information transmitting unit 13. The link establishing unit 19 selects the Xn link and transmits handover channel request acknowledge information to the source base station so that the candidate target base station is stably connected with the source base station.

While the preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all alterations and modifications as fall within the scope of the application.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A channel switching method of a mobile terminal is characterized by comprising the following steps:

and when the forwarding condition is met, the source base station sends switching channel request information containing the information of the candidate target base station to the core network through the NG interface.

2. The channel switching method of claim 1, wherein the candidate target base station sends the channel switching request acknowledgement message to the source base station, and the method specifically comprises the following steps:

3. The method of claim 1, wherein the terminal sends RRC reconfiguration complete information to the candidate target base station to complete channel switching, and specifically comprises the following steps:

and the candidate target base station sends switching success information to the source base station so as to indicate the completion of channel switching to the source base station.

4. The channel switching method of a mobile terminal according to claim 3, further comprising the steps of:

the core network sends path switching request acknowledge information to the candidate target base station, so that the core network replaces the source base station and is connected with the candidate target base station.

5. The channel switching method of a mobile terminal according to claim 1, further comprising the steps of:

6. A channel switching apparatus of a mobile terminal, comprising:

the switching channel request information acquisition unit is arranged at the source base station, is in communication connection with the core network, and is used for sending switching channel request information containing candidate target base station information to the core network;

a switching channel request information forwarding unit, which is arranged in the core network, is in communication connection with the candidate target base station, and is used for forwarding the switching channel request information to the candidate target base station so as to replace the source base station through the core network, thereby reducing the load of the source base station;

a switching channel request grant information sending unit, disposed in the candidate target base station, communicatively connected to the switching channel request information forwarding unit, and configured to send switching channel request grant information to the source base station;

an RRC reconfiguration information generating unit, provided in the source base station, communicatively connected to the handover channel request grant information transmitting unit, and configured to generate RRC reconfiguration information including information of the candidate target base station;

the RRC reconfiguration information sending unit is arranged on the source base station, is in communication connection with the RRC reconfiguration information generating unit, and is used for sending the RRC reconfiguration information containing the candidate target base station information to the terminal;

an RRC reconfiguration complete information sending unit, configured to the terminal, communicatively connected to the RRC reconfiguration information sending unit, and configured to send RRC reconfiguration complete information to the candidate target base station to complete channel switching;

the candidate target base station selection unit is arranged on the source base station and used for selecting a candidate target base station according to a measurement report reported by a terminal and a local switching strategy, the candidate target base station selection unit is in communication connection with the switching channel request information acquisition unit, the switching channel request information acquisition unit is provided with an NG interface, and the switching channel request information acquisition unit is in communication connection with a core network through the NG interface; the source base station is further configured to determine whether the number of candidate target base stations satisfies a forwarding condition.

7. The channel switching device of claim 6, further comprising: