KR102525369B1 - Mobile telecommunication base station server, mobile communication method and user device - Google Patents

Abstract

A mobile communication base station server according to embodiments includes a communication unit that transmits and receives data with a terminal having a first coverage band; a memory for storing data received from a terminal; and a controller that maintains or changes the coverage band of the terminal based on the movement speed of the terminal. includes

Description

Mobile communication base station server, mobile communication method and user terminal

Embodiments relate to a mobile communication base station, a mobile communication method, and a user terminal. For example, embodiments relate to a mobile communication base station server capable of switching coverage bands, a mobile communication method, and a user terminal.

In the process of discussing the 5G structure at the general meeting of the 3GPP standards body, the demand to satisfy the telecommunication operators of countries with rapid commercialization demand before 2020 and the need for time to research and create standard technologies that can create new services A demand was made.

In the process of discussing these two conflicting demands, various structural candidates were discussed. A 　Non Standalone (NSA) structure that provides LTE coverage and NR coverage at the same time by using it with the Term Evolution system has been introduced.

Under the current NSA structure, the 5G service is a method in which the terminal changes the path (ie, session) for exchanging data to improve the data processing speed between the terminal and the network based on the existing 4G service. For example, a terminal supporting 5G (hereinafter referred to as a "5G terminal" for convenience) communicates with a 5G base station (gNB) when it is within NR coverage, and communicates with a 4G base station (eNB) when within LTE coverage.

Meanwhile, mobile communication frequencies are classified into Low-Band, Mid-Band, and High-Band frequencies, and the bands can be divided into Small Coverage Band and Large Coverage Band through comparison of relative coverage of each frequency. At this time, the mid-band is classified as a large coverage band and the high-band as a small coverage band.

Compared to Mid-Band, High-Band has the advantage of having high transmission rate and low latency due to its wide bandwidth and short subframe size. However, the high-band has a problem in that the cell coverage is small due to the frequency characteristic with a large loss compared to the mid-band. Due to this, when the user equipment (UE) moves quickly, there is a problem in that the user equipment (UE) is not stably provided with a data service because very frequent cell changes occur.

In order to solve the above-described problems, embodiments are aimed at improving cell change that frequently occurs in a small coverage band.

In addition, embodiments aim to switch a serving cell frequency based on a preset condition to improve cell change.

In addition, the technical problems to be achieved through the embodiments are not limited to the above-mentioned matters, and other technical problems not mentioned above can be solved by those skilled in the art from various embodiments to be described below. can be considered

According to embodiments, a communication unit for transmitting and receiving data to and from a terminal having a first coverage band; a memory for storing data received from a terminal; and a controller that maintains or changes the coverage band of the terminal based on the movement speed of the terminal. wherein the control unit calculates the movement speed of the terminal based on the frequency of the signal received from the terminal, compares the movement speed of the terminal with a threshold value previously stored in a memory, and determines the movement speed of the terminal using a previously stored thread If the threshold value is exceeded, a command for switching the first coverage band to a second coverage band having a different coverage than the first coverage band is transmitted to the terminal through the communication unit, and the movement speed of the terminal is a pre-stored threshold value. Provided is a mobile communication base station server that maintains a first coverage band in the case of the following.

According to embodiments, obtaining, by a first base station, a movement speed of a terminal from a terminal; Comparing, by the first base station, the movement speed of the terminal with a preset value stored in the first base station; switching a coverage band of the terminal when the movement speed of the terminal exceeds a preset threshold value; and maintaining the coverage band when the movement speed of the terminal is equal to or less than a preset threshold value. Including, it provides a mobile communication method.

According to embodiments, the step of switching the coverage band of the terminal may include transmitting a coverage band switching command from the first base station to the terminal; and performing wireless communication with the second base station by the terminal; Including, it provides a mobile communication method.

According to embodiments, acquiring the movement speed of the terminal may include: receiving, by the first base station, a frequency of the terminal from the terminal; and calculating a movement speed of the terminal using the frequency of the terminal, the Doppler frequency which is a value pre-stored in the first base station, and the speed of light. Including, it provides a mobile communication method.

According to embodiments, before the step of obtaining the moving speed of the terminal, the terminal transmitting a sounding reference signal (SRS) signal to the first base station; and confirming whether the first base station corresponds to one of true and false values of a period flag; and wherein the first base station obtains the movement speed of the terminal only when the periodic flag is false.

According to embodiments, the first base station provides a mobile communication method in which the first base station waits until the next SRS signal is transmitted from the terminal when the periodic flag is true.

According to embodiments, when the movement speed of the terminal exceeds a preset threshold value, the first base station transmits a request for switching the coverage band of the terminal to the third base station, and the first base station transfers the third base station to the third base station. A mobile communication method is provided for transmitting a coverage band switch command to a terminal through the

According to embodiments, in a user terminal having a first coverage band, the communication unit for transmitting and receiving data to and from a base station; and a control unit maintaining or changing a coverage band of a user terminal. The control unit calculates the movement speed of the terminal, compares the movement speed of the terminal with a preset threshold value, and selects a first coverage band when the movement speed of the terminal exceeds the preset threshold value. A user terminal that transmits information for switching to a second coverage band having a coverage greater than the first coverage band to a base station through a communication unit and maintains the first coverage band when the mobile speed of the terminal is equal to or less than a preset threshold value. to provide.

According to embodiments, in transmitting switching information to a base station, the control unit transmits data including the movement speed of the user terminal, Doppler frequency, and base station operation procedure to the base station through the communication unit, and responds to the transmitted data. Provided is a user terminal that receives a coverage band switching command from a base station and transmits radio communication data to the base station in response to the received switching command.

According to the embodiments, the control unit, the communication unit receives a first signal including one of a radio resource control (RRC) configuration and an RRC configuration from a base station, a channel state information reference signal (CSI-RS) signal, and a synchronization signal block (SSB) Provided is a user terminal that calculates a moving speed of the user terminal only when a second signal including one of the above is received.

According to embodiments, when the first signal and the second signal are received through the communication unit, the control unit checks whether the periodic flag of the base station corresponds to true or false, and moves the user equipment only when the periodic flag is false. A user terminal that calculates the speed is provided.

According to embodiments, when the periodic flag is true, the control unit provides a user terminal that waits until the next second signal is received from the base station.

According to embodiments, the control unit provides a user terminal that calculates a moving speed of the user terminal for each preset period.

According to embodiments,

Receiving, by a terminal, a first signal from a third base station, wherein the first signal includes one of RRC (Radio Resource Control) configuration and RRC configuration; Receiving, by a terminal, a second signal from a first base station different from a third base station, wherein the second signal includes one of a Channel State Information Reference Signal (CSI-RS) and a Synchronization Signal Block (SSB); checking, by a terminal, whether a periodic flag of the first base station corresponds to true or false, corresponding to the first signal and the second signal, and calculating a movement speed of the terminal only when the periodic flag is false; Comparing, by a terminal, a movement speed of the terminal with a preset threshold value; When the movement speed of the terminal is less than or equal to a preset threshold value, the terminal maintains the coverage band, and when the movement speed of the terminal exceeds the preset threshold value, the movement speed of the terminal to the third base station, the Doppler frequency, and the base station transmits data including operating procedures, the terminal receives a command to switch the coverage band of the terminal from the third base station, and the terminal responds to the command to a second base station different from the first base station and the third base station A mobile communication method for transmitting wireless communication data is provided.

Embodiments may reduce the frequency of cell change occurring in a coverage band.

Embodiments may calculate the moving speed of the user terminal.

Embodiments may control, define, and/or drive a base station server and a user terminal to enable system operation according to user settings.

A further scope of applicability of the embodiments will become apparent from the detailed description that follows. However, since various changes and modifications within the spirit and scope of the embodiments can be clearly understood by those skilled in the art, it should be understood that the detailed description and specific embodiments such as preferred embodiments of the present invention are given as examples only.

1 is a diagram for explaining the structure of a mobile communication network according to embodiments.
2 is a diagram schematically illustrating a mobile communication system according to embodiments.
3 is a block diagram of a mobile communication base station server according to embodiments.
4 is a control flowchart of a mobile communication base station server according to embodiments.
5 is a flowchart of a mobile communication method including a terminal, a first base station, and a second base station in the mobile communication method according to embodiments.
6 is a flowchart of a mobile communication method including a terminal, a first base station, a second base station, and a third base station in a mobile communication method according to embodiments.
7 is a block diagram of a user terminal according to embodiments.
8 is a flowchart of a mobile communication method including a terminal, a first base station, and a second base station in the mobile communication method according to embodiments.
9 is a flowchart of a mobile communication method including a terminal, a first base station, a second base station, and a third base station in the mobile communication method according to embodiments.

Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings, but the same or similar components are given the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted. The suffixes "module" and "unit" for components used in the following description are given or used together in consideration of ease of writing the specification, and do not have meanings or roles that are distinct from each other by themselves.

In addition, in describing the embodiments disclosed in this specification, if it is determined that a detailed description of a related known technology may obscure the gist of the embodiment disclosed in this specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in this specification, the technical idea disclosed in this specification is not limited by the accompanying drawings, and all changes included in the spirit and technical scope of the present invention , it should be understood to include equivalents or substitutes.

Terms including ordinal numbers, such as first and second, may be used to describe various components, but the components are not limited by the terms. These terms are only used for the purpose of distinguishing one component from another. It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be.

On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "comprise" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

The mobile communication network according to the present invention may be configured based on the 4G standard 3GPP Long Term Evolution (LTE) and/or the 5G standard NR (New Radio), but this is only one embodiment, and the 4G standard and 5G It may be configured to interoperate with devices of a network other than the network element defined in the standard - for example, the IoT network.

Terminals referred to through the embodiments include fixed terminals or mobile terminals capable of communicating with the outside by wire or wirelessly, and user terminals, user equipment (UE), multimedia devices, and the like may be used interchangeably.

The base station server referred to through the embodiments is a server that controls each base station, and may be used interchangeably with a mobile communication base station server.

1 is a diagram for explaining the structure of a mobile communication network according to embodiments, and particularly shows the structure of a Non Standalone (NSA) system based on the 3GPP standard.

The NSA system is a system that uses NR (New Radio) technology together with the existing LTE system to provide LTE coverage and NR coverage at the same time, and is distinguished from the Stand Alone (SA) system that provides only NR coverage.

A base station supporting 5G NR use can be defined as gNB and en-gNB. The former is used only in a Stand Alone (SA) system that provides only NR coverage, and the latter is a base station used in a Non Standalone (NSA) system.

gNB is a next-generation base station that supports NR technology and interworking with 5G Core, and en-gNB is a new type of base station that supports interworking with NR technology and 5G Core and interworks with EPC, the core of the LTE system, and eNB, the base station. An eNB is a base station used in an LTE system that supports interworking with LTE technology and EPC (Enhanced Packet Core).

A technology in which a terminal supporting one or more RX/TX simultaneously uses resources controlled by one or more base stations is called Dual Connectivity (DC). The 5G NSA structure is based on the DC technology defined by the 3GPP standard organization.

Referring to FIG. 1, a mobile communication network according to an embodiment includes a User Equipment (UE) 10, an Evolved Node B (eNB) 20, a Serving Gateway (S-GW) 30, and a Packet Data Network Gateway (P-GW) 40. ), MME (Mobility Management Entity, 50), HSS (Home Subscriber Server, 60), PDN (Packet Data Network, 90).

The UE 10 is a user terminal conforming to LTE and/or NR standards, and may be connected to the eNB 20 through an LTE Uu interface. Here, the LTE Uu interface is a radio interface, and a control plane for transmitting and receiving control messages and a user plane for providing user data are defined.

The UE 10 may also interwork with a gNB (not shown), which is a base station supporting the NR standard, or an en-gNB 22, which is a base station supporting both LTE and NR standards.

The eNB 20 is a device that provides a radio interface to the UE 10, and provides radio resource management functions such as radio bearer control, radio admission control, dynamic radio resource allocation, load balancing, and inter-cell interference control. do.

The S-GW 30 is an end of an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) and an Evolved Packet Core (EPC), and serves as an anchoring point during handover between eNBs 20 and handover between 3GPP systems. do. Here, the E-UTRAN is composed of at least one eNB 20, and the EPC is composed of the S-GW 30, the P-GW 40, and the MME 50.

The P-GW 40 connects the UE 10 to an external Packet Data Network (PDN) 100 and performs a packet filtering function. In addition, the P-GW 40 allocates an IP address to the UE 10 and operates as a mobility anchoring point during handover between a 3GPP system and a non-3GPP system. In particular, the P-GW 40 receives a Policy and Charging Control (PCC) rule from the PCRF, applies it to a corresponding service flow, and provides a charging function for each UE 10/Service Date Flow (SDF).

The MME 50 provides an access control function for network connection of the UE 10, a network resource allocation function, a tracking function, a paging function, a roaming function, a handover function, etc. can do. The MME 50 may manage a plurality of eNBs 20 and select a gateway by performing predetermined signaling for handover to an existing 2G/3G network.

In addition, the MME 50 may perform authentication and security setting procedures for the access UE 10 in conjunction with the HSS 60, and may manage location information of idle terminals. The MME 50 may obtain an authentication vector from the HSS 60 and perform mutual authentication with the UE 10 using the authentication vector. When the authentication procedure is completed, the MME 50 may set a security key for security between the UE 10 and the MME 50 .

The HSS 60 is a database in which a subscriber profile is stored, and provides user authentication information and a user profile to the MME 50 .

Uu is a radio interface between the UE 10 and the eNB 20 and provides a control plane and a user plane.

S1-U is an interface between the eNB 20 and the S-GW 30 and provides a user plane. At this time, GTP tunneling for each bearer is provided.

S5 is an interface between the S-GW 30 and the P-GW 40 and provides a control plane and a user plane. In this case, the user plane provides GTP tunneling for each bearer, and the control plane provides GTP tunnel management.

SGi defines a user plane and a control plane as an interface between the P-GW 40 and the PDN 90. In the user plane, an IETF-based IP packet forwarding protocol is used, and in the control plane, protocols such as DHCP and RADIUS/Diameter are used.

S11 is an interface between the MME 50 and the S-GW 30, a control plane is defined, and GTP tunneling is provided per bearer.

X2 is an interface between two eNBs 20 or two base stations (eNB 20 and En-gNB 22) supporting different radio access technologies (RATs), and provides a control plane and a user plane. In the control plane, the X2-AP protocol is used, and in the user plane, GPRS Tunneling Protocol (GTP) tunneling per bearer is provided for data forwarding during X2 handover.

S6a provides a control plane as an interface between the HSS 60 and the MME 50, and is used to exchange UE subscription information and authentication information.

2 is a diagram schematically illustrating a mobile communication system according to embodiments.

In FIG. 2 , a mobile communication system 3000 (eg, the mobile communication network described in FIG. 1 ) includes a base station 1000 (eg, the base station described in FIG. 1 ) and a terminal 2000 (eg, the mobile communication network described in FIG. 1 ). The terminal described above) is included.

A base station 1000 according to embodiments includes a first base station 1100 and a second base station 1200 . The first base station 1100 and the second base station 1200 are different. The first base station 1100 and the second base station 1200 are base stations capable of communicating with the terminal 2000 . At least one of the first base station 1100 and the second base station 1200 may provide a communication service to a terminal.

Although not shown in FIG. 2, two or more of the terminal 2000, the first base station 1100, and the second base station 1200 may communicate with each other through an access point (AP). The access point is a relay located in an area where at least one of the first base station 1100 and the second base station 1200 can provide a communication service or within a communication area.

The terminal 2000 according to embodiments includes a fixed terminal or a mobile terminal capable of communicating with the outside by wire or wirelessly. In addition, the terminal includes a terminal supporting 2G, 3G, 4G, LTE and 5G services. In addition, terminals include, for example, mobile phones, smart phones, laptop computers, digital broadcasting terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), navigation devices, and slate PCs. , Tablet PC, Ultra Book, digital TV, desktop computer, etc. A description of the terminal 2000 will be given below in FIG. 7 .

The terminal 2000 receives a communication service from the first base station 1100 and the second base station 1200 .

The terminal 2000 receives a communication service within the first coverage band 1101 from the first base station 1100 . The first coverage band 1101 is, for example, a small coverage band. The first coverage band 1101 has, for example, a high-band as a mobile communication frequency.

The first coverage band 1101 has a wide bandwidth and a short subframe size. Accordingly, the terminal 2000 receives a communication service having a high transmission rate and low latency from the first base station 1100 . However, the first coverage band 1101 has a problem in that the cell coverage is small due to a frequency characteristic with a large loss. Therefore, when the terminal 2000 moves quickly along the arrow a, there is a problem in that the cell change 1100c occurs frequently.

Meanwhile, the terminal 2000 may receive a communication service within the second coverage band 1201 from the second base station 1200 . The second coverage band 1201 is, for example, a large coverage band. The second coverage band 1201 has, for example, a low-band as a mobile communication frequency.

The second coverage band 1201 has wider cell coverage than the first coverage band 1201 . Therefore, even if the terminal 2000 moves quickly along the arrow a, the cell change 1200c does not occur frequently.

Accordingly, in order to prevent frequent cell change 1100c of the terminal 2000 belonging to the first coverage band 1101 when a user carrying the terminal 2000 moves quickly, the first coverage band 1101 ) into the second coverage band 1201 is required. Hereinafter, specific methods for solving the above problems will be described.

3 is a block diagram of a mobile communication base station server according to embodiments.

As shown in FIG. 3 , the base station server 1000 according to the embodiments includes a communication unit 1010, a memory 1020, and a control unit 1030.

The communication unit 1010 according to embodiments transmits and receives data with the terminal 2000 (see FIG. 2). The communication unit 1010 can communicate with the terminal 2000 wirelessly or wired. The communication unit 1010 includes at least one of a broadcast receiving module, a mobile communication module, a wireless Internet module, a short-distance communication module, and a location information module.

At this time, the broadcast reception module receives a broadcast signal and/or broadcast-related information from an external broadcast management server through a broadcast channel.

The mobile communication module is a technology standard or communication method for mobile communication, for example, GSM (Global System for Mobile communication), CDMA (Code Division Multi Access), WCDMA (Wideband CDMA), HSDPA (High Speed Downlink Packet Access) ), at least one of a base station (e.g., 1100, 1200, see FIG. 5), an external terminal (e.g., 2000, see FIG. 5), and a server in a mobile communication network built according to LTE (Long Term Evolution) transmits and receives radio signals.

The wireless signal may include a voice call signal, a video call signal, or various types of data according to text/multimedia message transmission/reception.

The wireless Internet module is a module for wireless Internet access, and is built into or external to the base station server 1000 and/or the base station. The wireless Internet module is configured to transmit and receive wireless signals in a communication network based on wireless Internet technologies (eg, wireless LAN (WLAN), wireless fidelity (WiFi), etc.).

The short-range communication module is for short-range communication, and supports short-range communication using, for example, Bluetooth, Radio Frequency Identification (RFID), ZigBee, and the like. The short-distance communication module supports wireless communication between the base station server 1000 and the base station, and between the base station server 1000 and the terminal through a short-range wireless personal communication network.

The location information module checks and tracks location information of a terminal capable of transmitting and receiving data with the base station server 1000 and/or a base station. The location information module collects the current location of the terminal and/or the base station in real time and/or the past location using, for example, a Global Positioning System (GPS) signal.

The memory 1020 according to embodiments stores data received from a terminal and/or a base station. The memory 1020 stores various information about the base station including a communication history of the terminal, location information about the base station, identification information, and the like. The memory 1020 stores all communication histories between a terminal and a base station and between a terminal and other terminals.

The control unit 1030 according to embodiments controls all components included in the base station server 1000 . Also, the controller 1030 maintains or changes the coverage band of the terminal based on the movement speed of the terminal. A control process in which the controller 1030 maintains or changes the coverage band based on the movement speed of the terminal will be described in detail with reference to FIG. 4 .

4 is a control flowchart of a mobile communication base station server according to embodiments.

The control method described below includes a control method performed by the base station server 1000, but not limited thereto, and a control method performed by each base station (eg, a first base station and a second base station). .

As shown in FIG. 4, the control method of the mobile communication base station server 1000 includes obtaining and/or calculating the movement speed of the terminal from the terminal 2000 (see FIG. 5) (s101).

The base station server 1000 calculates the movement speed of the terminal based on the frequency of the signal received from the terminal. Specifically, the base station server 1000 receives the frequency of the terminal from the terminal. After that, the base station server 1000 calculates the movement speed of the terminal through the frequency of the terminal and the Doppler frequency, which is a value pre-stored in the memory (see FIG. 3 1020), and the speed of light. At this time, the movement speed of the terminal is calculated according to [Equation 1] below.

는 단말(2000)의 이동 속도이고,

는 단말의 주파수이고,

는 도플러 주파수이고, C는 광속을 나타낸다. 그러나, 단말(2000)의 이동 속도는 상기 식으로만 구할 수 있는 것은 아니며, 단말(2000)의 주파수와 반비례하는 관계를 갖는 다른 식을 통하여도 구할 수 있다.At this time,

is the movement speed of the terminal 2000,

is the frequency of the terminal,

is the Doppler frequency, and C represents the speed of light. However, the movement speed of the terminal 2000 can not be obtained only by the above formula, but can also be obtained through another formula having an inversely proportional relationship with the frequency of the terminal 2000.

Alternatively, the base station server 1000 obtains the movement speed of the terminal based on the location information module described in FIG. 2 . Alternatively, the base station server 1000 receives the movement speed of the terminal from the terminal.

As shown in FIG. 4, the control method of the mobile communication base station server 1000 includes a step of comparing the movement speed of the terminal and a threshold value (s102). The threshold value is a value pre-stored in memory. Alternatively, the threshold value is a value set by the controller 1020 based on data received from the terminal 2000 .

As shown in FIG. 4, the control method of the mobile communication base station server 1000 proceeds to step s104 when the moving speed of the terminal is greater than the threshold value, and the moving speed of the terminal is equal to the threshold value or If it is less than the threshold value, proceeding to step s105 (s103) is included.

As shown in FIG. 4, the control method of the mobile communication base station server 1000 includes transmitting a coverage band switch command to the terminal when the moving speed of the terminal is greater than a threshold value (S104). Through this, a user using the terminal can receive a communication service within the second coverage band having a large cell coverage, thereby minimizing inconvenience caused by frequent cell changes.

As shown in FIG. 4, the control method of the mobile communication base station server 1000 includes maintaining the coverage band of the terminal when the moving speed of the terminal is equal to or smaller than the threshold value (s105). includes Through this, the user using the terminal can minimize the inconvenience caused by frequent cell changes since the movement speed is less than or equal to the preset threshold value, while providing a communication service with a high transmission rate and low latency within the first coverage band. can be provided.

Hereinafter, embodiments in which a base station itself performs a procedure for reducing cell change will be described. In this case, the following procedure includes content performed by a base station controlled by a base station server or content performed by a base station server, even when described as content performed by the base station itself.

In addition, the mobile communication base station server, mobile communication method, and user terminal according to the embodiments described below are conditions for frequency conversion of the base station and the terminal, for example, base station parameters capable of operating the system and UE IE (User Equipment Information Element) ) can be defined. In this case, the base station parameter and the UE IE are values that allow the user terminal to switch the frequency provided according to the movement speed of the user terminal, and include a threshold value described/to be described herein.

5 is a flowchart of a mobile communication method including a terminal, a first base station, and a second base station in the mobile communication method according to embodiments.

As shown in FIG. 5, a mobile communication system 3000 performing a mobile communication method includes a terminal 2000, a first base station 1100 (eg, gNB described in FIG. 1) and a second base station 1200, For example, the gNB described in FIG. 1) is included.

The first base station 1100 is, for example, a 5G base station and has a frequency with small band coverage. The second base station 1200 is, for example, a 5G base station and has a frequency with large band coverage.

As shown in FIG. 5, the mobile communication method includes a step (s201) of transmitting a Sounding Reference Signal (SRS) signal from the terminal 2000 to the first base station 1100.

As shown in FIG. 5, the mobile communication method includes a step s202 in which the first base station 1100 checks whether a period flag is true or false. .

At this time, the periodic flag refers to a flag continuously initialized to a false value based on the periodic time of the frequency switching condition set in the first base station 1100. At this time, if the value of the periodic flag is false, step S204 is performed to determine the frequency conversion. If the value of the periodic flag is true, frequency switching is not determined and waits until the next SRS signal is received from the terminal 2000 (S203). That is, the first base station 1100 obtains the movement speed of the terminal only when the periodic flag is false.

The first base station 1100 further includes receiving a frequency of the terminal from the terminal 2000 in order to obtain the movement speed of the terminal 2000 . The frequency of the terminal is performed in real time regardless of the order of s201 to s203. For example, the first base station 1100 receives information about the frequency of the terminal at least once every 60 ms from the terminal.

The first base station 1100 calculates the movement speed of the terminal based on the received frequency of the terminal 2000 . The first base station 1100 calculates the movement speed of the terminal through the frequency of the terminal 2000, the Doppler frequency, which is a value pre-stored in the first base station, and the speed of light. The movement speed of the terminal is calculated according to [Equation 1] described in FIG. 4 . At this time, the Doppler frequency and light speed may be values stored in a memory (not shown) included in the first base station 1100, or a memory 1020 included in a base station server (eg, the base station server described in FIG. 3). , see FIG. 3) and may be a value received from the communication unit 1010 (see FIG. 3) of the base station server. Alternatively, the Doppler frequency and light speed may be values received by a communication unit (not shown) included in the first base station 1100 from an external device or crawled by accessing an external server.

As shown in FIG. 5 , the mobile communication method includes a step s205 in which the first base station 1100 compares the movement speed of the terminal 2000 with a threshold value when the value of the periodic flag is false. The threshold value may be a value pre-stored in the memory of the first base station 1100 . Alternatively, the threshold value may be a value stored in the memory 1020 of the base station server 1000 and received by the first base station 1100 from the base station server 1000 . At this time, the threshold value means a frequency conversion condition.

The mobile communication method performs s207 when the movement speed of the terminal is greater than the threshold value, and s206 when the movement speed of the terminal is equal to the threshold value or the movement speed of the terminal 2000 is less than the threshold value Do it.

As shown in FIG. 5, in the mobile communication method, when the movement speed of the terminal 2000 is equal to the threshold value or the movement speed of the terminal is smaller than the threshold value, the first base station 1100 determines the terminal 2000 ) without switching the coverage band (s206). Since the movement speed of the terminal 2000 is slow, a problem in which a user feels inconvenience due to frequent cell changes does not occur. Therefore, without changing the coverage band, the existing coverage band (eg, the first coverage band described in FIG. 2, a small coverage band) is maintained to promote user convenience.

As shown in FIG. 5 , in the mobile communication method, when the movement speed of the terminal 2000 is greater than the threshold value, the first base station 1100 transmits a coverage band switch command to the terminal 2000 . The first base station 1100 transmits a coverage band switching command to the terminal in order to switch the coverage band of the terminal 2000 . The coverage band switching command is for switching the serving frequency of the terminal (eg, including switching from a first coverage band to a second coverage band), and transmits a command including redirection or handover. By switching the coverage band, the user can comfortably use the terminal 2000 without frequent cell changes.

As shown in FIG. 5 , the mobile communication method includes a step s208 in which the terminal 2000 transmits wireless communication data to the second base station 1200 . The radio communication data includes, for example, serving cell switching information. That is, after performing a redirection or handover procedure, the terminal 2000 completes switching the serving cell to the second coverage band.

6 is a flowchart of a mobile communication method including a terminal, a first base station, a second base station, and a third base station in a mobile communication method according to embodiments.

As shown in FIG. 6, a mobile communication system 3000 performing a mobile communication method includes a terminal 2000, a first base station 1100 (eg, gNB described in FIG. 1), a second base station 1200, For example, the gNB described in FIG. 1) and the third base station 1300 (eg, eNB described in FIG. 1) are included.

The first base station 1100 is, for example, a 5G base station and has a frequency with small band coverage. The second base station 1200 is, for example, a 5G base station and has a frequency with large band coverage. The third base station 1300 is, for example, a 5G base station or a 4G base station, and has a wider coverage band than the first base station and a narrower coverage band than the second base station.

Since s201 to s206 shown in FIG. 6 are the same as or similar to s201 to s206 described with reference to FIG. 5 , descriptions thereof are omitted.

As shown in FIG. 6, the mobile communication method includes a step of transmitting a coverage band switch request from the first base station 1100 to the third base station 1300 (S209). Specifically, the first base station 1100 transmits a request for switching the coverage band of the terminal to the third base station when the movement speed of the terminal exceeds a preset threshold value. At this time, the request for switching the coverage band of the terminal includes redirection or handover (HO).

As shown in FIG. 6, the mobile communication method includes a step s210 in which the terminal 2000 receives a command corresponding to the request from the third base station 1300. That is, the third base station 1300 transmits a command including redirection or handover to switch the coverage band of the terminal.

As shown in FIG. 6 , the mobile communication method includes a step s211 in which the terminal 2000 transmits wireless communication data to the second base station 1200 . The radio communication data includes, for example, serving cell switching information. That is, the terminal 2000 performs a redirection or handover procedure in response to a command received from the third base station 1300, and then switches the serving cell to the second coverage band.

Hereinafter, a user terminal included in a mobile communication system according to embodiments will be described.

7 is a block diagram of a user terminal according to embodiments.

As shown in FIG. 7, the user terminal 2000 includes a communication unit 2010 that transmits and receives data with the outside and a control unit that changes or maintains the coverage band of the user terminal 2000 based on the moving speed of the user terminal 2000. (2020).

The communication unit 2010 according to embodiments transmits and receives data with a base station (eg, a first base station and a second base station, see FIG. 5). The communication unit 2010 can communicate with the base station wirelessly or wired. The communication unit 2010 includes at least one of a broadcast receiving module, a mobile communication module, a wireless Internet module, a short-distance communication module, and a location information module.

At this time, the broadcast reception module receives a broadcast signal and/or broadcast-related information from an external broadcast management server through a broadcast channel.

The mobile communication module is a technology standard or communication method for mobile communication, for example, GSM (Global System for Mobile communication), CDMA (Code Division Multi Access), WCDMA (Wideband CDMA), HSDPA (High Speed Downlink Packet Access) ), transmits and receives a radio signal with at least one of a base station (eg, 1100 and 1200, see FIG. 5), an external terminal, and a server in a mobile communication network built according to LTE (Long Term Evolution).

The wireless signal may include a voice call signal, a video call signal, or various types of data according to text/multimedia message transmission/reception.

The wireless Internet module is a module for wireless Internet access, and is built into or external to the base station server 1000 and/or the base station. The wireless Internet module is configured to transmit and receive wireless signals in a communication network based on wireless Internet technologies (eg, wireless LAN (WLAN), wireless fidelity (WiFi), etc.).

The short-range communication module is for short-range communication, and supports short-range communication using, for example, Bluetooth, Radio Frequency Identification (RFID), ZigBee, and the like. The short-range communication module supports short-range communication between the terminal 2000 and the base station server 1000 and between the terminal 2000 and the base station through a short-range wireless personal communication network.

The location information module measures the current location of the terminal 2000 . The location information module measures the current location of the terminal 2000 at predetermined intervals. Alternatively, the location information module checks and tracks location information of a terminal capable of transmitting and receiving data with the terminal 2000 and/or a base station. The location information module collects a current location of an object in real time and/or a past location using, for example, a Global Positioning System (GPS) signal.

The controller 2020 according to embodiments controls all configurations included in the user terminal 2000 . The controller 2020 maintains or changes the coverage band of the terminal 2000 based on the movement speed of the terminal 2000 . A control process in which the terminal 2000 maintains or changes the coverage band based on the movement speed of the terminal 2000 will be described in detail with reference to FIGS. 8 and 9 .

8 is a flowchart of a mobile communication method including a terminal, a first base station, and a second base station in the mobile communication method according to embodiments.

As shown in FIG. 8, a mobile communication system 3000 performing a mobile communication method includes a terminal 2000, a first base station 1100 (eg, gNB described in FIG. 1) and a second base station 1200, For example, the gNB described in FIG. 1) is included.

The terminal 2000 is provided with a communication service from the first base station 1100 . The first base station 1100 is, for example, a 5G base station and has a frequency with small band coverage. The second base station 1200 is, for example, a 5G base station and has a frequency with large band coverage.

As shown in FIG. 8 , the user terminal 2000 receives the first signal from the first base station 1100 (S301).

The first signal includes, for example, Radio Resource Control (RRC) configuration or RRC reconfiguration. The first signal is, for example, defined in FIG. 4 and includes an Information Element (IE) or parameter for frequency conversion. The first signal includes a measurement object and measurement report configuration. The measurement object includes the current serving frequency of the user terminal 2000. The measurement report configuration is a value to be measured by the user terminal 2000, and includes, for example, a frequency of the user terminal 2000, a moving speed of the user terminal 2000, and a Doppler frequency.

As shown in FIG. 8, the user terminal 2000 receives the second signal from the first base station 1100 (S302).

The second signal includes a control signal transmitted from the first base station 1100 to the user terminal 2000, data, and a reference signal. The first base station 1100 sets, for example, a reference signal (CSI-RS) signal or a synchronization signal block (SSB) to transmit the second signal to the user terminal 2000. Thus, the second signal includes, for example, CSI-RS or SSB.

The user terminal 2000 performs steps s304 and below only when receiving the first signal and the second signal from the first base station 1100 . That is, the user terminal 2000 determines whether the periodic flag is false and calculates the movement speed of the user terminal 2000 only when the first signal and the second signal are received from the first base station 1100 .

As shown in FIG. 8 , the user terminal 2000 checks whether the period flag is true or false (S304). At this time, the periodic flag is determined by the IE included in the first signal. The periodic flag refers to a flag continuously initialized to a false value based on the IE cycle time. At this time, if the value of the periodic flag is false, the process proceeds to step S306 to determine the frequency conversion. If the value of the periodic flag is true, frequency switching is not determined and waits until the next second signal is received from the first base station 1100 (S305). That is, the user terminal 2000 acquires the movement speed of the terminal only when the periodic flag is false.

As shown in FIG. 8 , when the periodic flag is false, the terminal 2000 calculates the movement speed of the terminal 2000 (S306).

The user terminal 2000 calculates the movement speed of the terminal based on the frequency of the user terminal 2000 . The user terminal 2000 calculates the movement speed of the terminal through the frequency and Doppler frequency of the user terminal 2000 and the speed of light. The movement speed of the terminal 2000 is calculated according to [Equation 1] described in FIG. 4 .

At this time, the Doppler frequency and light speed may be values stored in a memory (not shown) included in the user terminal 2000, or a memory included in a base station server (eg, the base station server described in FIG. 3) (1020, As a value stored in FIG. 3), it may be a value received from the communication unit 1010 (see FIG. 3) of the base station server. Alternatively, the Doppler frequency and light speed may be values received by the communication unit (2010, see FIG. 7) from an external device or crawled by accessing an external server.

In addition, the terminal 2000 may acquire the movement speed of the terminal using a speed measurement module (not shown) included in the terminal 2000 .

As shown in FIG. 8 , the user terminal 2000 compares the moving speed of the user terminal 2000 with a preset threshold value (S307). At this time, the threshold value means a frequency conversion condition. The threshold value may be a value previously stored in a memory (not shown) of the user terminal 2000 .

Alternatively, the threshold value may be a value stored in the memory 1020 of the base station server 1000 and received by the first base station 1100 from the base station server 1000 . The threshold value may be a value included in the first signal.

Alternatively, the user terminal 2000 may set the threshold value by itself. The user terminal 2000 measures a Doppler frequency based on the first signal received from the first base station 1100, and calculates a moving speed of the user terminal 2000 and a range of an appropriate coverage band. In this case, the range of an appropriate coverage band refers to a range of coverage bands in which a cell change occurs less than a preset number of times during a preset time when the user terminal 2000 moves at the current speed. In this case, information about a preset time and a preset number of times may be included in the first signal. Alternatively, information on the preset time and the preset number of times may be stored in the user terminal 2000 . Alternatively, information on a preset time and a preset number of times may be received from the base station server 1000 .

The user terminal 2000 may set the threshold value based on the current coverage band and the calculated appropriate coverage band. At this time, the threshold value is set in consideration of the number of cell changes that occur when the current coverage band is maintained and the change in transmission speed and other services that occur when switching to an appropriate coverage band.

The user terminal 2000 performs step s309 when the moving speed of the user terminal 2000 is greater than the threshold value, and the moving speed of the user terminal 2000 is equal to or greater than the threshold value. When the moving speed is smaller than the threshold value, s308 is performed.

As shown in FIG. 8, the user terminal 2000 transmits data to the first base station 1100 (S309). At this time, the data is for switching the coverage band of the user terminal 2000 and includes UE Assistance Information (UAI) or a measurement report. In this case, the UAI or measurement report includes at least one of the movement speed of the user terminal 2000, a measurement event, a Doppler speed, and operation procedures of the first to third base stations.

As shown in FIG. 8 , the user terminal 2000 receives a coverage band switching command from the first base station 1100 (S310). That is, the first base station 1100 transmits a command including redirection or handover to switch the coverage band of the terminal.

As shown in FIG. 8 , the user terminal 2000 includes a step s311 of transmitting wireless communication data to the second base station 1200 . The radio communication data includes, for example, serving cell switching information. That is, after performing a redirection or handover procedure in response to a command received from the first base station 1300, the terminal 2000 switches the serving cell to the second coverage band.

9 is a flowchart of a mobile communication method including a terminal, a first base station, a second base station, and a third base station in the mobile communication method according to embodiments.

As shown in FIG. 9, a mobile communication system 3000 performing a mobile communication method includes a terminal 2000, a first base station 1100 (eg, gNB described in FIG. 1), a second base station 1200, For example, the gNB described in FIG. 1) and the third base station 1300 (eg, eNB described in FIG. 1) are included.

The terminal 2000 is provided with a communication service from the first base station 1100 . The first base station 1100 is, for example, a 5G base station and has a frequency with small band coverage. The second base station 1200 is, for example, a 5G base station and has a frequency with large band coverage. The third base station 1300 is, for example, a 5G base station or a 4G base station, and has a wider coverage band than the first base station and a narrower coverage band than the second base station.

As shown in FIG. 9, the user terminal 2000 receives the first signal from the third base station 1300 (S302). A description of the first signal is the same as or similar to that described in FIG. 8 and thus omitted. Since s303 to s308 shown in FIG. 9 are the same as or similar to s303 to s308 described in FIG. 8 , descriptions thereof are omitted.

As shown in FIG. 9, the user terminal 2000 transmits data to the third base station 1300 (S312). At this time, the data is for switching the coverage band of the user terminal 2000 and includes UAI or measurement report. In this case, the UAI or measurement report includes at least one of the movement speed of the user terminal 2000, a measurement event, a Doppler speed, and operation procedures of the first to third base stations.

As shown in FIG. 9 , the user terminal 2000 receives a coverage band switching command from the third base station 1300 (S313). That is, the third base station 1300 transmits a command including redirection or handover to switch the coverage band of the terminal.

As shown in FIG. 9 , the user terminal 2000 transmits wireless communication data to the second base station 1200 (S314). The radio communication data includes, for example, serving cell switching information. That is, the terminal 2000 performs a redirection or handover procedure in response to a command received from the third base station 1300, and then switches the serving cell to the second coverage band.

Although not shown, embodiments are a mobile communication system including the user terminal 2000, the first base station 1100, the second base station 1200, and the third base station 1300 described in FIGS. 7 and 8 (eg , 3000).

Although the mobile communication system according to the embodiment of the present invention, the mobile communication base station, user terminal, and mobile communication method included in the mobile communication system have been described as specific embodiments, this is only an example, and the present invention is not limited thereto, It should be construed as having the widest scope according to the basic idea disclosed herein.

A person skilled in the art may implement an embodiment that is not indicated by combining or substituting the disclosed embodiments, but this also does not deviate from the scope of the present invention. In addition, those skilled in the art can easily change or modify the disclosed embodiments based on this specification, and it is clear that such changes or modifications also fall within the scope of the present invention.

1000: base station server
1100: first base station
1200: second base station
1300: third base station
2000: Terminal
3000: mobile communication system

Claims (14)

a communication unit for transmitting and receiving data with a terminal having a first coverage band;
a memory for storing data received from the terminal; and
a control unit that maintains or changes a coverage band of the terminal based on a moving speed of the terminal;
including,
The control unit,
When a Sounding Reference Signal (SRS) signal is received from the terminal, it is checked whether it corresponds to either true or false of a period flag,
When the periodic flag is false, calculating a movement speed of the terminal based on a frequency of a signal received from the terminal;
Comparing the moving speed of the terminal with a threshold value pre-stored in the memory, and when the moving speed of the terminal exceeds the pre-stored threshold value, the first coverage band is selected as a coverage band different from the first coverage band. Transmitting a command for switching to a second coverage band having , to the terminal through the communication unit, and maintaining the first coverage band when the moving speed of the terminal is less than or equal to the pre-stored threshold value;
Mobile communication base station server. Transmitting, by a terminal, a Sounding Reference Signal (SRS) signal to a first base station;
checking whether the first base station corresponds to one of true and false values of a period flag;
obtaining, by the first base station, a moving speed of the terminal from the terminal when the periodic flag is false;
Comparing, by the first base station, the movement speed of the terminal with a preset value stored in the first base station;
switching a coverage band of the terminal when the moving speed of the terminal exceeds the preset threshold value; and
maintaining the coverage band when the moving speed of the terminal is less than or equal to the preset threshold value;
including,
mobile communication method. According to claim 2,
The step of switching the coverage band of the terminal,
transmitting, by the first base station, a coverage band switch command to the terminal; and
performing, by the terminal, wireless communication with a second base station;
including,
mobile communication method. According to claim 2,
Obtaining the movement speed of the terminal,
receiving, by the first base station, a frequency of the terminal from the terminal; and
calculating a movement speed of the terminal using the frequency of the terminal, a Doppler frequency that is a value pre-stored in the first base station, and the speed of light;
including,
mobile communication method. delete According to claim 2,
The first base station waits until the next SRS signal is transmitted from the terminal when the periodic flag is true.
mobile communication method. According to claim 2,
When the movement speed of the terminal exceeds the preset threshold value, the first base station transmits a request for switching the coverage band of the terminal to a third base station;
The first base station transmits a coverage band switching command to the terminal through the third base station.
mobile communication method. In a user terminal having a first coverage band,
Communication unit for transmitting and receiving data with the base station; and
a controller that maintains or changes a coverage band of the user terminal;
including,
The control unit,
A first signal that the communication unit includes one of RRC (Radio Resource Control) configuration and RRC reconfiguration from the base station; and a second signal including one of a Channel State Information Reference Signal (CSI-RS) and a Synchronization Signal Block (SSB); receive,
Check whether the periodic flag of the base station corresponds to true or false,
When the periodic flag is false, the movement speed of the terminal is calculated, the movement speed of the terminal is compared with a preset threshold value, and the movement speed of the terminal exceeds the preset threshold value. When information for switching the first coverage band to a second coverage band having a greater coverage than the first coverage band is transmitted to the base station through the communication unit, and the movement speed of the terminal is less than or equal to the preset threshold value maintaining the first coverage band;
user terminal. According to claim 8,
In transmitting the switching information to the base station,
The control unit,
Transmitting data including a movement speed, a Doppler frequency, and a base station operation procedure of the user terminal to the base station through the communication unit;
Receiving a coverage band switching command from the base station in response to the transmitted data;
Transmitting wireless communication data to the base station in response to the received switch command,
user terminal. delete delete According to claim 8,
The controller waits until the next second signal is received from the base station when the periodic flag is true.
user terminal. According to claim 9,
The control unit calculates the moving speed of the user terminal for each predetermined period,
user terminal. Receiving, by a terminal, a first signal from a third base station, wherein the first signal includes one of RRC (Radio Resource Control) configuration and RRC configuration;
Receiving, by the terminal, a second signal from a first base station different from the third base station, wherein the second signal includes one of a Channel State Information Reference Signal (CSI-RS) and a Synchronization Signal Block (SSB);
The terminal checks whether the periodic flag of the first base station corresponds to true or false in response to the first signal and the second signal, and calculates the movement speed of the terminal only when the periodic flag is false. doing;
comparing, by the terminal, a movement speed of the terminal with a preset threshold value;
When the movement speed of the terminal is less than or equal to the preset threshold value, the terminal maintains a coverage band, and when the movement speed of the terminal exceeds the preset threshold value, the terminal is transferred to the third base station. Transmitting data including movement speed, Doppler frequency, and base station operating procedures;
The terminal receives a command to switch the coverage band of the terminal from the third base station,
The terminal transmits wireless communication data of the terminal to a second base station different from the first base station and the third base station in response to the command,
mobile communication method.

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