KR102038850B1 - method for managing of mobile telecommunication system - Google Patents

Abstract

According to the present invention, a cell suitable for a moving speed of a terminal in a 5G mobile communication system in which a beam antenna is arranged to cover each unit area after partitioning a cell controlled by a base station by using different unit areas (over multiple layers) The present invention relates to a method for operating a base station of a mobile communication system, by performing beam switching using an antenna, thereby preventing the degradation of communication quality caused by frequent beam switching.
In the method of operating a base station of the mobile communication system of the present invention, the base station cell is partitioned into a plurality of beam spots using a unit area, but is divided into a plurality of layers using a unit area having a different area to cover each unit area. It is performed between the base station and the terminal that has a millimeter wave beam antenna, and the base station periodically performs a master information block (MIB) including beam antenna layer information of the base station and different reference speeds of one or more terminals, which are set differently according to the moving speed of the terminal. (A) transmitting to; (B) the terminal measuring its moving speed; (C) determining, by the UE, its own moving speed step based on the reference speed information received through the MIB; and using the beam antenna on the layer corresponding to the speed step, the UE uses a base station system information block (SIB). And after the decoding, accessing the base station using the decoded information.
In the above configuration, the terminal calculates its own moving speed based on the GPS data received by the built-in GPS receiver.
The MIB further includes carrier frequency information set differently for each moving speed of the terminal.
The unit area is set larger as the moving speed of the terminal increases, and the carrier frequency is set to a higher frequency as the moving speed of the terminal increases.

Description

Method for managing base station in mobile communication system {method for managing of mobile telecommunication system}

The present invention relates to a method of operating a base station of a mobile communication system, and in particular, a beam antenna to cover each unit area after partitioning a cell controlled by a base station by using different unit areas in a 5G mobile communication system. The present invention relates to a method for operating a base station of a mobile communication system to prevent a decrease in communication quality caused by frequent beam switching by performing beam switching by using a beam antenna suitable for a moving speed of a terminal in a state of arranging.

The International Telecommunication Union (ITU) held a radiocommunication conference in October 2015 and designated the official technology name of 5G as 'International Mobile Telecommunication (IMT-20-2020)'. It stands for. Unlike 4G, which uses frequencies below 2 GHz, 5G uses ultra-high frequency, ie millimeter waves, below 6 kHz and above 24 kHz.

Table 1 below is a table for explaining the frequency operation scheme of the 5G mobile communication system proposed by 3GPP, Table 2 is a table showing the preferred frequency band of each country.

According to the definition of the International Telecommunication Union (ITU), 5G is a mobile communication technology with a maximum download speed of 20 Gbps and a minimum download speed of 100 Mbps, which provides Internet of Things (IoT) services to 1 million devices within a radius of 1 ㎢. In addition, it must support free communication even at high speed trains of 500 kilometers per hour. The download speed of 5G is 70 times faster than the current mobile communication speed of 300Mbps and 280 times faster than general LTE, and it can download a 1GB movie in 10 seconds.

In addition, in 4G, the response speed is about 10 ~ 50Hz, but 5G supports the response speed of about 10 times faster than this, so autonomous vehicles or the Internet of Things that need to send and receive a large amount of data seamlessly with the central server ( 5G is expected to be actively introduced in the IoT field.

The talk of 5G has been in full swing since 2015. The International Telecommunication Union (ITU) and the International Civil Technology Standardization Organization, 3GPP, plan to complete the 5G standard by several international meetings by 2020. In addition, discussions on 5G are in full swing in each country, with Korea creating the 5G Forum, China making the IMT-2020, Japan making the ARIB, and thinking about the future direction of 5G.

On the other hand, the propagation in the millimeter wave frequency band is a narrow beam by concentrating the energy of the antenna because the loss of free space is severe, the loss due to atmospheric and rainfall attenuation is large, the straightness is strong, and the propagation loss by diffraction and transmission is large. ) In the form of.

In consideration of this, in the base station of the 5G mobile communication system, it is expected that a multi-beam type in which beams in a predetermined direction covering a certain area (beam spot) are divided and covers the entire area is used. In this case, the base station covers its cell area. Many narrow beams are used for this purpose.

1 is a physical configuration diagram of a base station of a 5G mobile communication system that can be applied to the method of the present invention. As shown in FIG. 1, in the 5G mobile communication system, the mobile communication cell 20 covered by one base station includes, for example, a plurality of beam spots (16 in the example of FIG. 1) arranged in a matrix form. beam spot), and each beam spot may be covered by a beam radiated from a plurality of antenna elements corresponding to one-to-one correspondence or one-to-one M (but M is plural).

Each antenna element may be implemented as a patch antenna or a horn antenna. In FIG. 1, the antenna array 10 is formed by arranging such antenna elements in a matrix form, for example, in a 4 * 4 matrix form.

2 is a sequence chart showing a beam switching procedure expected to be used in a 5G mobile communication system. As shown in FIG. 2, a user terminal (UE) connected to a 5G base station reports the measured signal quality information to the base station after measuring the quality of the received signal. When the terminal moves between beams, The quality of the measured received signal is constantly changing. In this process, if the quality of the signal received from the serving beam (Serving Beam) that the terminal is currently serving is equal to the quality (M1) of the signal received from the adjacent target beam (T-Beam; Target Beam) The measured quality information is transmitted to the serving beam, and the base station sends the information of the target beam to the RRC (Radio Resource Control) Reconfiguration message based on the quality information. In this state, when the terminal continues to move toward the target beam so that the signal quality of the serving beam is lower than the reference quality of the target beam (M2), the base station performs beam switching in a manner instructing the terminal to access the target beam. Doing so ensures a fast and seamless service.

3 is a diagram illustrating a problem of a beam switching method that is expected to be applied to a 5G mobile communication system. As shown in FIG. 3, according to the beam switching method that is expected to be applied to a 5G mobile communication system, when a terminal moves an arbitrary base station cell from A to B direction, beam 1 → beam 5 → beam 6 → beam 7 → Beam 11 → Beam 12 → Beam 16 A total of 7 beam switching occurs. If the speed of the terminal is slow, there is no problem, but if it is fast, there is a possibility that the communication quality may be degraded due to the communication delay due to frequent beam switching. There was a big problem.

(Non-Patent Literature)-Prior Art 1: Paper presented at the Korean Institute of Communication Sciences 2017 Winter Conference

(Patent Document 1)-Prior art 2: Korean Patent Publication No. 10-2015-0095503 (name of the invention: method and apparatus for connecting a beam base station)

(Patent Document 2) Prior Art 3: 10-2016-0004003 Published Patent Publication (name of the invention: handover method and apparatus thereof)

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and in the 5G mobile communication system, a beam antenna is arranged to cover each unit area after partitioning cells (or layers) by using different unit areas. It is an object of the present invention to provide a method of operating a base station in a mobile communication system that can prevent the degradation of communication quality caused by frequent beam switching by performing beam switching using a beam antenna suitable for a moving speed of a terminal in an arrangement state. .

In the method of operating a base station of a mobile communication system of the present invention for achieving the above object, the base station cell is divided into a plurality of beam spots using a unit area, but is divided into a plurality of layers using unit areas having different areas. Later, the MIB is performed between the base station and the terminal, which have the millimeter wave beam antennas arranged to cover each unit area, and includes the base station's beam antenna layer information of the base station configured differently according to the moving speed of the terminal and the moving reference speed of one or more terminals. (A) periodically transmitting a (Master Information Block); (B) the terminal measuring its moving speed; (C) determining, by the UE, its own moving speed step based on the reference speed information received through the MIB; and using the beam antenna on the layer corresponding to the speed step, the UE uses a base station system information block (SIB). And after the decoding, accessing the base station using the decoded information.

In the above configuration, the terminal calculates its own moving speed based on the GPS data received by the built-in GPS receiver.

The MIB further includes carrier frequency information set differently for each moving speed of the terminal.

The unit area is set larger as the moving speed of the terminal increases, and the carrier frequency is set to a higher frequency as the moving speed of the terminal increases.

According to a method for operating a base station of a mobile communication system of the present invention, a beam antenna is arranged to cover each unit area after partitioning a cell controlled by a base station using different unit areas in a 5G mobile communication system (over multiple layers). By performing beam switching using a beam antenna suitable for the moving speed of the terminal in one state, it is possible to prevent the degradation of communication quality caused by frequent beam switching.

1 is a physical configuration diagram of a base station of a 5G mobile communication system that can be applied to the method of the present invention.
2 is a sequence chart showing a beam switching procedure expected to be used in a 5G mobile communication system.
3 is a diagram illustrating a problem of a beam switching method expected to be applied to a 5G mobile communication system.
4 is a diagram illustrating a beam partitioning scheme of a base station cell according to a base station operating method of a mobile communication system of the present invention.
5 is a base station functional block diagram of a 5G mobile communication system to which the method of the present invention can be applied.
6 is a flowchart illustrating a method for operating a base station in a mobile communication system of the present invention.
7A and 7B are diagrams for explaining a beam switching method through a mid-range beam and a wide-area beam, respectively, in a method for operating a base station of a mobile communication system of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the base station operating method of the mobile communication system of the present invention.

In the following, a user terminal may be a user equipment (UE), a mobile terminal (MT), a mobile station (MS), an advanced mobile station (AMS), a high reliability mobile station. High Reliability Mobile Station (HR-MS), Subscriber Station (SS), Portable Subscriber Station (PSS), Access Terminal (AT) or Mobile Xhaul Network (MXN) ) May refer to an MXN terminal of a network, etc., and may include all or part of the functions of the UE, MT, MS, AMS, HR-MS, SS, PSS, AT, or MXN terminal described above.

In addition, the base station (BS) is a Node B (B), an advanced Node B (eNB), an Advanced Base Station (ABS), a High Reliability Base Station (HR-BS). ), An Access Point (AP), a Radio Access Station (RAS), a Base Transceiver Station (BTS), or an MXN hub, and the like. The Node B, eNB, BS, It may also include all or part of the functionality of the ABS, HR-BS AP, RAS, BTS or MXN hub.

4 is a diagram illustrating a beam partitioning scheme of a base station cell according to a base station operating method of a mobile communication system of the present invention. As shown in FIG. 4, according to the method of operating a base station of the mobile communication system of the present invention, after each cell area is divided (over several layers) by using a unit area having a different area, each unit area is covered. The beam antenna is arranged so as to.

More specifically, in the present embodiment, the base station cell is partitioned into unit areas having different areas on a total of three layers, and the base station cell is partitioned into a total of 16 unit areas as shown in FIG. In the upper layer, beams covering each unit area are divided into eight unit areas by combining two lower unit areas and divided into four unit areas by combining two unit areas in the upper layer. The antenna is installed. Hereinafter, the lower, middle, and upper layers of the unit region are referred to as 'narrow beam', 'medium beam' and 'wide beam' in terms of beams, respectively. Beam antenna 'and' wide beam antenna '.

In this state, the present invention preferably uses beam antennas on different layers according to the moving speed of the terminal. For example, the first stage speed Speed_1 in which the moving speed of the terminal is less than the first reference speed R _S1 . In the case of, the narrow short-wavelength beam antenna of, for example, 28 GHz is used as a relatively short wavelength. Similarly, if the moving speed of the terminal is the second step speed Speed_2 that is greater than or equal to the first reference speed R _S1 and less than the second reference speed R _S2 , for example, a mid-range beam of 26 GHz having a relatively straight wavelength and a moderate straightness is also medium. If the antenna is used, and if the moving speed of the terminal is the third step speed_3 that is greater than or equal to the second reference speed R _S2 , a narrow-beam beam antenna of 3.5 kW having a relatively low linearity as a relative long wavelength is used.

5 is a functional block diagram of a base station of a 5G mobile communication system to which the method of the present invention can be applied. As shown in FIG. 5, the base station of the 5G mobile communication system to which the method of the present invention can be applied includes an analog signal having a beam antenna (not shown) corresponding to one to one or one to M in each of a plurality of beam spots. A plurality of RF modules 100 for processing a radio signal, a physical layer processing unit (hereinafter, simply referred to as a 'PHY processing unit') 110, which correspond one to one or one M to each RF module 100, respectively. The upper layer procedure of the MAC scheduler 130 and the MAC layer connected to each MAC processing unit 120, MAC (Media Access Control) processing unit 120 corresponding to one or one M to the PHY processing unit 110 The upper layer processor 140 may be configured.

In the above-described configuration, each RF module 100 converts an analog RF signal received through the antenna array 10 into a baseband signal in a digital form, and then transfers the RF signal to the PHY processing unit 110 or the PHY processing unit 110. After converting the baseband signal of the digital form received from the analog signal into the RF signal of the analog form and transmits wirelessly through the antenna array (10).

The PHY processor 110 performs general physical layer functions such as channel coding and decoding of data and control signals, digital modulation / demodulation, multiple antenna mapping, and radio resource mapping. The MAC processing unit 120 performs periodic or aperiodic periods of general location information such as mapping between logical channels and transport channels, error correction, distribution of time and frequency resources for a plurality of terminals, and current location information from a terminal having jurisdiction. It reports to the MAC scheduler 130, and performs beam switching, frequency resource distribution, etc. according to the instructions of the MAC scheduler (130).

The MAC scheduler 130 receives terminal information covered by each MAC processor 120, that is, each beam periodically or aperiodically from each MAC processing unit 120, and uses carrier frequencies and beam antenna layers for each moving speed of the terminal. Number of antennas), bandwidth information used, reference speed information, and the like are periodically transmitted, for example, in a MIB (Master Information Block).

Next, the upper layer processor 140 transmits data by segmentation and concatenation processing, transmission error, and retransmission management of a packet, which transmits data by adjusting the packet size from the upper PDCP layer to the MAC layer size. PDCP performs functions such as RLC (Radio Link Control) layer for improved reliability, compression of IP packet headers, encryption of control messages and user data, data integrity and data loss prevention during handover (Packet Data Convegence Protocol) layer and Radio Resource Control (RRC) layer between the terminal and the radio access network (Radio Bearer) can be made including a radio resource control (RCC) layer that performs a comprehensive set of functions associated with the radio bearer (Radio Bearer), the higher The layer processor 140 is based on an LTE or LTE-A system, that is, 3G or 4G, so that the 5G may be properly applied. It may change.

6 is a flowchart illustrating a method for operating a base station in a mobile communication system of the present invention. As shown in FIG. 6, the base station 100 periodically transmits a MIB toward the terminal 200 (step S10). In this process, the conventional MIB includes information such as a physical cell ID and a system frame number (SFN). Is transmitted as is, but the carrier frequency, the beam antenna layer (antenna number) and the downlink frequency bandwidth information of the base station is set to transmit differently according to the moving speed of the terminal, for this purpose, the reference speed of the plurality of terminals, for example, the first And second reference speed (R _S1 , R _S12 ) information together.

6 again, the terminal 200 periodically measures its own moving speed (step S20). The measurement of the moving speed is calculated by the received data of the built-in GPS receiver or according to the distance information between the beams. Can be estimated. Next, the terminal 200 determines its own moving speed step based on the reference speed information received through the MIB from the base station 100 (step S30), and then uses a beam antenna of a frequency band suitable for its speed step. To decode the System Information Block (SIB) of the base station 100 (step S40). Finally, the terminal 200 accesses the base station 100 by using the decoded information and then starts communication (step S50).

7A and 7B are diagrams for explaining a beam switching scheme using a mid-range beam and a wide-area beam, respectively, in a method for operating a base station of a mobile communication system of the present invention. As shown in FIG. 7A, when the terminal 200 moves from point A to point B at a second stage speed Speed_2 that is greater than or equal to the first reference speed R _S1 and less than the second reference speed R _S12 . The terminal 200 performs beam switching using a mid-beam beam antenna according to the MIB information transmitted from the base station 100. As a result, a total of four beam switching occurs from the mid-beam 1 to the mid-beam 2 to the mid-beam 7 to the mid-beam 8, and the number of beam switching remarkably increases compared to the number 7 of beam switching using a conventional narrow-beam antenna. As a result, quality degradation such as communication delays caused by frequent beam switching can be reduced.

As shown in FIG. 7B, when the terminal 200 moves from the point A to the point B at the third speed Speed_3 that is greater than or equal to the second reference speed R _S12 , the terminal 200 uses a broadband beam. The beam switching is performed. Accordingly, a total of three beam switching occurs from the wide beam 1 to the wide beam 2 to the wide beam 4, which is compared with the number 7 of beam switching using a conventional narrow beam antenna. Is significantly reduced, and as a result, quality degradation such as communication delay due to frequent beam switching can be reduced.

The preferred embodiments of the method for operating a base station in a mobile communication system of the present invention have been described in detail above with reference to the accompanying drawings, which are merely examples, and various modifications and changes may be made within the scope of the technical idea of the present invention. Therefore, the scope of the present invention will be defined by the description of the claims below. For example, in the above-described embodiment, the base station cell is divided into three layers, but the size of the layer or the unit area may be appropriately increased or decreased according to the overall size or characteristics of the base station cell.

10: antenna array, 20: base station cell,
100: base station, 200: user terminal

Claims (4)

A base station and a terminal that divide a base station cell into a plurality of beam spots by using a unit area, and divide a base station cell into a plurality of layers by using a unit area having a different area, and then arrange a millimeter wave beam antenna to cover each unit area. Is performed between
(A) periodically transmitting, by the base station, a MIB (Master Information Block) including beam antenna layer information of the base station configured differently for each moving speed of the terminal and moving reference speeds of one or more terminals;
(B) the terminal measuring its moving speed;
(C) determining, by the terminal, its own moving speed step based on the reference speed information received through the MIB; and
And (d) accessing the base station using the decoded information after the terminal decodes the base station system information block (SIB) using a beam antenna on a layer suitable for the speed step.
The MIB further includes carrier frequency information set differently for each moving speed of the terminal.
The unit area is set larger as the moving speed of the terminal increases.
The carrier frequency is a base station operating method of a mobile communication system, characterized in that the higher the moving speed of the terminal is set to a higher frequency. The method according to claim 1,
The terminal calculates its own moving speed based on GPS data received by the built-in GPS receiver. delete delete

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