WO2021053816A1

WO2021053816A1 - Relay device, relay method, and relay system

Info

Publication number: WO2021053816A1
Application number: PCT/JP2019/037027
Authority: WO
Inventors: 基貴飯田; 将彦南里; 真規野町; 充弘近藤; 和人野口; 志郎福元; 阿部　達朗
Original assignee: ソフトバンク株式会社
Priority date: 2019-09-20
Filing date: 2019-09-20
Publication date: 2021-03-25
Also published as: JPWO2021053816A1; JP7386254B2

Abstract

Provided are a relay device, a relay method, and a relay system capable of suppressing a decrease in throughput. Provided are a base station device, a terminal device and a wireless communication method which can expand a coverage area through a method differing from conventional methods.　The relay device relays communication between a donor cell base station and a terminal device by using a first cell, and comprises: a management unit for managing cell identification information in which a cell is associated with a base station that forms the cell, and registering cell identification information on a second cell which is different from the first cell; a notification unit which notifies the terminal device of the cell identification information on the second cell; a first acquisition unit which acquires synchronization information for synchronizing with communication using the second cell between the terminal device and the base station associated with the cell identification information on the second cell; and a timing control unit which controls a timing of a frame when relaying communication from the donor cell base station to the terminal device, on the basis of the synchronization information.

Description

Relay device, relay method, and relay system

The present invention relates to a relay technique for relaying communication between a terminal device and a macrocell base station.

In Release 8 of 3GPP (The 3 rd G eneration P artnership P roject) to develop standards for mobile communications, LTE (L ong T erm E volution) are defined and operated as a communication standard (Non-Patent Document 1 ). LTE In other mobile communication systems conforming to the communication standards, the terminal device (UE: U ser E quipment) in order to improve the coverage, macrocells (Macro-cell) Small cell having a small coverage area than the base station ( Small-cell) Base station is used. Small cell base station, access (AC: Ac cess Link) through a communication path connected to the terminal device. The small cell base station backhaul (BH: B ack h aul Link ) mobile operators via the communication path (MNO: M obile N etwork O perator) is connected to a core network which operates. As a technique related to such a small cell base station, a relay device that allocates different frequency bands to the access communication path and the backhaul communication path has been devised (Patent Document 1). In addition, a standard for sharing a wireless communication path with a plurality of mobile networks has also been proposed (Non-Patent Document 2).

Japanese Unexamined Patent Publication No. 2016-171536

In mobile communication systems as described in the prior art documents, a relay device that can be installed more easily than a base station is used to expand the coverage area of the entire system.

However, the cells formed by the relay device are compared with the cells of the base stations existing in the vicinity due to reasons such as a narrow frequency band in the relay device, congestion of communication between the terminal device and the backhaul, and generation of weak electricity. Throughput was sometimes low.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a relay device, a relay method, and a relay system capable of suppressing a decrease in throughput.

The relay device according to one aspect of the present invention is a relay device that relays communication between a donor cell base station and a terminal device using a first cell, and cell identification information for associating a cell with a base station forming the cell. The management unit that manages the registration of the second cell, the management unit that registers the cell identification information of the second cell different from the first cell, the notification unit that notifies the terminal device of the cell identification information of the second cell, and the second cell. From the donor cell base station based on the synchronization information and the first acquisition unit that acquires the synchronization information for synchronizing with the communication using the second cell between the base station and the terminal device associated with the cell identification information of It includes a timing control unit that controls the timing of frames when relaying communication to a terminal device.

The relay method according to one aspect of the present invention is a relay method for relaying communication between a donor cell base station and a terminal device using a first cell, and cell identification information for associating a cell with a base station forming the cell. The step of managing the registration of the cell, the step of registering the cell identification information of the second cell different from the first cell, the step of notifying the terminal device of the cell identification information of the second cell, and the cell identification of the second cell. The step of acquiring synchronization information for synchronizing with the communication using the second cell between the base station and the terminal device associated with the information, and the communication from the donor cell base station to the terminal device based on the synchronization information. Includes a step to control the timing of the frame when relaying.

The relay system according to one aspect of the present invention includes a relay device that relays communication between a donor cell base station and a terminal device using a first cell, and a cell formed by the base station and the base for each of the plurality of base stations. A base station management device that manages cell identification information associated with a station and position information indicating the position of the base station, and a base station within a predetermined distance from the position of the relay device responds to a request from the relay device. The base station management device that responds to the cell identification information of the cells to be formed is provided, and the relay device is a management unit that manages the registration of the cell identification information, and receives the cell identification information of the second cell different from the first cell. A management unit to be registered, a notification unit for notifying the terminal device of the cell identification information of the second cell, and communication using the second cell between the base station and the terminal device associated with the cell identification information of the second cell. The management unit is equipped with an acquisition unit that acquires synchronization information for synchronization and a timing control unit that controls the frame timing when relaying communication from the donor cell base station to the terminal device based on the synchronization information. , The cell identification information included in the response from the base station management device is registered as the cell identification information of the second cell.

The relay system according to one aspect of the present invention provides a relay device that relays communication between a donor cell base station and a terminal device using a first cell, and reference time information indicating a reference time to each of a plurality of base stations. The relay device includes a time management device, and the relay device is a management unit that manages registration of cell identification information that associates a cell with a base station forming the cell, and is a cell identification information of a second cell different from the first cell. Communication using the second cell of the management unit for registering the cell, the notification unit for notifying the terminal device of the cell identification information of the second cell, and the base station and the terminal device associated with the cell identification information of the second cell. An acquisition unit that acquires synchronization information for synchronizing with and a timing control unit that controls the frame timing when relaying communication from the donor cell base station to the terminal device based on the synchronization information. Acquires reference time information as synchronization information, and the timing control unit receives from the donor cell base station based on the deviation time from the reference time and the propagation delay time in communication with the time management device calculated from the reference time information. Advances the frame timing when relaying communication to the terminal device.

According to the present invention, it is possible to suppress a decrease in throughput.

FIG. 1 is a schematic diagram showing an example of the configuration of the mobile communication system according to the first embodiment. FIG. 2 is a schematic diagram showing a modified example of the configuration of the mobile communication system according to the first embodiment. FIG. 3 is a configuration diagram illustrating a hardware configuration of a relay device centered on a split / integrated unit. FIG. 4 is a schematic diagram illustrating the operation of the backhaul communication unit. FIG. 5 is a schematic diagram illustrating the basic operation of the division / integration unit. FIG. 6 is a flowchart illustrating a schematic operation of carrier aggregation by the relay device. FIG. 7 is a configuration diagram illustrating the software configuration of the control unit. FIG. 8 is a schematic diagram illustrating an example of the first method of selecting the second cell. FIG. 9 is a schematic diagram illustrating another example of the first method of selecting the second cell. FIG. 10 is a schematic diagram illustrating a second method of selecting the second cell. FIG. 11 is a schematic diagram illustrating a third method of selecting the second cell. FIG. 12 is a schematic diagram illustrating an example of a fourth method of selecting the second cell. FIG. 13 is a schematic diagram illustrating another example of the fourth method of selecting the second cell. FIG. 14 is a schematic diagram illustrating an example of the operation of the synchronization information acquisition unit. FIG. 15 is a schematic diagram illustrating another example of the operation of the synchronization information acquisition unit. FIG. 16 is a schematic diagram illustrating still another example of the operation of the synchronization information acquisition unit. FIG. 17 is a schematic diagram schematically showing the configuration of the relay system according to the second embodiment. FIG. 18 is a configuration diagram illustrating a software configuration of the control unit. FIG. 19 is a schematic diagram illustrating the operation of the synchronization information acquisition unit. FIG. 20 is a schematic diagram schematically showing the configuration of the relay system according to the third embodiment. FIG. 21 is a configuration diagram illustrating a software configuration of the control unit. FIG. 22 is a schematic diagram illustrating the operation of the timing control unit.

An embodiment of the present invention will be described below. In the description of the drawings below, the same or similar parts are represented by the same or similar reference numerals. However, the drawings are schematic. Therefore, the specific dimensions and the like should be determined in light of the following explanations. In addition, it goes without saying that the drawings include parts having different dimensional relationships and ratios from each other. Furthermore, the technical scope of the present invention should not be construed as limited to the embodiment.

[First Embodiment]
<Relay device>
First embodiment of the present invention, different mobile operators: Basic form of (MNO M obile N etwork O perator ) is a mobile communication network MN (M obile N etwork) simultaneously connectable relay apparatuses to operate It is a thing. In the following description, different mobile carriers shall be identified by lowercase letters of the alphabet. For example, the device XY, which is a system or configuration associated with the mobile communication carrier a, is indicated by adding a lowercase letter a to the device XY.

(Overall system)
FIG. 1 is a schematic view showing an example of the configuration of the mobile communication system 100 according to the first embodiment. FIG. 2 is a schematic view showing a modified example of the configuration of the mobile communication system 100 according to the first embodiment. As shown in FIG. 1, the mobile communication system 100 includes

terminal devices

10a and 10b, a relay device 20, and mobile communication networks MNa and MNb.

Terminals

10a and 10b, a smart phone, a mobile communication terminal such as a cellular phone, in the drawings referred to as UE (U ser E quipment). Hereinafter, when it is not necessary to associate with a mobile communication operator, it is simply referred to as "terminal device 10".

The mobile communication network MNa is a basic system operated by the mobile communication operator a, and the mobile communication network MNb is a basic system operated by the mobile communication operator b. FIG. 1 illustrates a case where only the mobile communication network MNa managed by the mobile communication operator a and the mobile communication network MNb managed by the mobile communication operator b are connected for the sake of simplicity. are doing. However, the mobile communication system 100 may be connected to a mobile communication network managed by another mobile communication operator.

Hereinafter, for the sake of simplicity, it is assumed that the mobile communication network MNa and the mobile communication network MNb include the same configuration. In addition, when it is not necessary to distinguish the mobile communication network in particular, the symbols of the numbers will be described without lowercase letters.

(Mobile communication network)
The mobile communication network MN includes a donor-cell base station 30, a macro cell base station 35, and a core network 70.

The donor cell base station 30 has a configuration as a so-called macro-cell base station. The donor cell base station refers to a large number of macrocell base stations 35 in which a backhaul communication path is established by a terminal device, a relay device, and a wireless bearer. Particularly in the LTE standard, sometimes referred donor cell base station DeNB (D onor eN ode B) . Donor cell base station 30 and the macro cell base station 35, each radio access network: that operates to form (RAN R adio A ccess N etwork ). The donor cell base station 30 is configured to establish a backhaul communication path BH with the relay device 20 and also establish a direct access communication path AC with the terminal device 10. The donor cell base station 30 and the macro cell base station 35 each provide a macro cell, which is a service area having a radius of several hundred meters to a dozen kilometers, by generating relatively high-power radio waves.

The core network 70 includes a first core network 40, a second core network 60, and a virtual base station device 50. The second core network 60 is connected to an external network 80 (public data network). Each of the first core network 40 and the second core network 60, also referred to as EPC (E volved P acket C ore ) , especially the LTE standard. FIG. 1 shows an example in which the first core network 40a and the second core network 60a are constructed on the same network EPCa.

The first core network 40 is connected to the donor cell base station 30, and is a network that mainly controls the donor cell base station 30 to manage the establishment / cancellation of the backhaul communication path BH.

The second core network 60 is a network that mainly manages the relay device 20 and the terminal device 10 that is directly connected to the relay device 20. For example, the second core network EPC60 performs position management of the relay device 20, connection control of outgoing / incoming calls to the terminal device 10 connected to the relay device 20, billing management, and the like.

The virtual base station device 50 is connected to the first core network 40 and the second core network 60. The virtual base station device 50 is provided attached to the relay device 20 and has a configuration as a computer device. The virtual base station apparatus 50 realizes the following functions by executing a predetermined software program.

The functions executed by the virtual base station apparatus 50a are the function of recognizing the parameters including the first identification information IDa assigned to the first mobile communication network MNa and the functions assigned to the second mobile communication network MNb. This is a function of converting a parameter including the second identification information IDb into a parameter including the first identification information IDa. The functions executed by the virtual base station apparatus 50b (not shown) are similarly a function of recognizing a parameter including a second identification information IDb assigned to the second mobile communication network MNb and a function of recognizing a parameter including a second identification information IDb and a first mobile communication network. This is a function of converting a parameter including the first identification information IDa assigned to the MNa into a parameter including the second identification information IDb. The converted parameters are provided to the relay device 20. By the virtual base station device 50, the relay device 20, the donor cell base station 30a of the first core network 40a, the macro cell base station 35a of the network EPCa, the donor cell base station 30b, and the macro cell base station 35b are placed on the same EPC. It can be regarded as a base station.

The external network 80 is a broadband network connected via an IP transmission device (router or the like) (not shown), and is typically the Internet.

The configuration of the mobile communication network MN described above is an example, and is not limited to this. For example, as shown in FIG. 2, the first core network 40 and the second core network 60 are not constructed on the same network, and may be different networks, respectively. The second core network 60 is connected to the macrocell base station 35. The virtual base station device 50 is installed between the first core network 40 and the second core network 60. In this case, the virtual base station device 50 makes it possible to regard the relay device 20, the macro cell base station 35a of the second core network 60a, and the macro cell base station 35b as base stations on the same EPC.

(Relay device)
As shown in FIG. 1, the relay device 20 is a relay device that relays communication between the terminal device 10 and the donor cell base station 30, and is an access communication unit 22, a division / integration unit 24, and a backhaul communication unit 26. To be equipped. In the drawings, the relay device 20 is also referred to as UR (U ser Equipment R elay) .

With the above-described components, the relay device 20 of the present embodiment is configured to be able to implement the following relay method for relaying the communication between the terminal device 10 and the donor cell base station 30.
(1) A step of connecting to one or more terminal devices 10 (access communication unit 22).
(2) A step of establishing a backhaul communication path BH associated with a specific identification information ID with a donor cell base station 30 associated with the specific identification information ID (backhaul communication unit 26).
(3) A step of connecting the terminal device 10 associated with the specific identification information ID to the specific backhaul communication path BH associated with the specific identification information ID (division / integration unit 24).

Hereinafter, the components that execute each step will be specifically described.
The access communication unit 22 is a communication device that connects to one or more terminal devices 10. In FIG. 1, the access communication unit 22 is commonly connected to the terminal device 10a associated with the mobile communication carrier a and the terminal device 10b associated with the mobile communication carrier b. The access communication unit 22 constructs a small cell which is a service area having a radius of several meters to several tens of meters by generating a radio wave having a relatively low output with respect to the terminal device 10. Therefore, the access communication unit 22, in the LTE standard, pico eNB (e volved N ode B) , a femto eNB, also referred to as a home eNB. In the drawings referred to an access communication unit 22 and the SC (S mall- c ell). The access communication unit 22 is connected to any terminal device 10 via radio waves in the same frequency band to form an access communication path AC. The access communication unit 22 demodulates the uplink data received from each terminal device 10 and outputs it as a block of packet data in the order of reception. Further, the access communication unit 22 modulates a block of packet data, which is downlink data provided by the division / integration unit 24, with a carrier wave of a common frequency band, and transmits the block via the access communication path AC. Both the uplink data and the downlink data are composed of a plurality of packet data blocks. The corresponding mobile communication carrier can be identified by the identification information ID given to each block. The access communication unit 22 is mainly composed of hardware. However, it is also possible to configure the access communication unit 22 so that the control unit, which will be described later, performs the same function by executing the software program.

Of the packets, the packet that flows through the data link layer of the OSI basic reference model is also called a frame. In this case, the packet data is also called frame data.

The backhaul communication unit 26 establishes a backhaul communication path BH associated with the specific identification information ID with the donor cell base station 30 associated with the specific identification information. In FIG. 1, the backhaul communication unit 26a establishes a backhaul communication path BHa with the donor cell base station 30a associated with the identification information IDa that identifies the mobile communication carrier a. Further, the backhaul communication unit 26b establishes a backhaul communication path BHb with the donor cell base station 30b associated with the identification information IDb that identifies the mobile communication carrier b. The uplink data and the downlink data transmitted and received via the backhaul communication path BH are radio waves modulated by a carrier wave in the frequency band specified by the corresponding donor cell base station 30, respectively. Backhaul communication unit 26, customer premises equipment: also called (CPE C ustomer P remises E quipment ). The backhaul communication unit 26 is mainly composed of hardware. However, it is also possible to configure the backhaul communication unit 26 so that the control unit, which will be described later, performs the same function by executing the software program.

The backhaul communication path BH formed by the backhaul communication unit 26 is a path for transmitting packet data via an antenna. The packet data may be modulated by a carrier wave in a predetermined frequency band according to a predetermined modulation method according to a communication standard.

Division integration unit (SCU: S plitting and C ombining U nit) 24 is connected to a specific backhaul communication path BH associated terminal device 10 associated with the particular identification information ID to the specific identification information ID It is configured to do. The division / integration unit 24 is functionally realized, for example, by operating predetermined hardware with software.

Next, the hardware configuration of the relay device 20 will be described with reference to FIG. FIG. 3 is a configuration diagram illustrating a hardware configuration of the relay device 20 centered on the division / integration unit 24. As shown in FIG. 3, the division / integration unit 24 includes a control unit 200, a storage unit 204, and interface circuits 206 and 210.

Control unit

200, CPU (C entral P rocessing U nit), ASIC (A pplication S pecific I ntegrated C ircuit), a processor 201, such as FPGA (F ield P rogrammable G ate A rray), ROM (R ead O nly M emory), comprising a memory such as a RAM (R andom a ccess M emory ), the. The control unit 200 realizes the function of the division / integration unit 24 by the processor 201 executing the computer software program stored in the memory 202. However, it is also possible to configure the division / integration unit 24 only by hardware so as to perform the same function.

The interface circuit 206 is a connection means for transmitting and receiving an integrated data CD to and from the access communication unit 22. The interface circuit 210 is a connection means for transmitting and receiving divided data SD with each backhaul communication unit 26.

The storage unit 204 is a memory configured to read data in the order of writing. Specifically, in the uplink, the storage unit 204 sequentially stores the packet data received from the terminal device 10 via the antenna 222 by the access communication unit 22 and supplied to the internal bus via the interface circuit 206. Then, the packet data sequentially read from the storage unit 204 under the control of the control unit 200 is sent to the backhaul communication unit via the interface circuit 210 associated with the identification information ID in block units associated with the identification information ID. It is transferred to 26 and transmitted from the antenna 262 toward the donor cell base station 30. Further, in the downlink, packet data received by the backhaul communication unit 26 from the antenna 262 and supplied to the internal bus via the interface circuit 210 is stored in the order in which the storage unit 204 receives the packet data. Then, the packet data sequentially read from the storage unit 204 under the control of the control unit 200 is transferred to the access communication unit 22 via the interface circuit 206 as an integrated data CD in block units associated with the identification information ID, and the antenna. It is transmitted from 222 toward the terminal device 10.

Note that the block diagram shown in FIG. 3 is merely an example, and it is possible to configure the block diagram so as to perform the same function by different configurations. For example, in the above-mentioned block diagram, the uplink data and the downlink data are supplied to the internal bus managed by the control unit 200, but the access communication unit 22 and the backhaul communication unit 26 are directly connected via the buffer memory. , The control unit 200 can be configured to perform only the entire control function. Such a configuration is appropriate when the communication speed is relatively high or the traffic capacity is large.

Next, the function of the backhaul communication unit 26 will be described with reference to FIG. FIG. 4 is a schematic diagram illustrating the operation of the backhaul communication unit 26. As shown in FIG. 4, a plurality of backhaul communication units 26 are provided in parallel corresponding to the identification information ID that identifies the mobile communication operator.

Identification information ID is unique information for identifying the mobile operator, for example, public land mobile networks: available for (PLMN P ublic L and M obile N etwork) number. The PLMN number consists of a 3-digit country code and a 2-3-digit network number that identifies the operator. However, the identification information ID may be assigned by a system other than the PLMN number. Hereinafter, for the sake of simplicity, the identification information of the mobile communication carrier a will be referred to as IDa.

In FIG. 4, the backhaul communication unit 26a establishes a backhaul communication path BHa with the donor cell base station 30a associated with the identification information IDa that identifies the mobile communication operator a, and connects to the access communication unit 22. The terminal device 10a to be connected is connected to the mobile communication network MNa. Further, the backhaul communication unit 26b establishes a backhaul communication path BHa with the donor cell base station 30b associated with the identification information IDb that identifies the mobile communication operator b, and connects to the access communication unit 22. The terminal device 10b is connected to the mobile communication network MNb. Further, the backhaul communication unit 26c establishes a backhaul communication path BHc with the donor cell base station 30c associated with the identification information IDc that identifies the mobile communication operator c, and connects to the access communication unit 22. The terminal device 10c is connected to the mobile communication network MNc. In this way, it is possible to provide a backhaul communication unit 26x capable of establishing a specific backhaul communication path BHx for any mobile communication carrier x whose business is permitted.

Each of the backhaul communication units 26 is provided with means for limiting the connection destination. The connection destination limiting means has a function of permitting connection only to a specific mobile communication carrier and prohibiting connection to other mobile communication carriers. Representative examples of such restriction means include SIM (S ubscriber I dentity M odule ) is. By providing SIM in each of the backhaul communication units 26, the donor cell base station 30 recognizes the backhaul communication unit 26 corresponding to each mobile communication operator as a UE.

Identification information IDx for identifying a specific mobile communication carrier x is assigned to the SIM. The SIM can only connect to the mobile communication network MNx operated by the mobile communication operator x specified by the identification information IDx assigned to each, and the SIM can connect to the mobile communication operated by the other mobile communication operator y. Connection to network MNy is restricted. In the present embodiment, the identification information IDa, IDb, and IDc are assigned to the SIMs provided in each of the

backhaul communication units

26a, 26b, and 26c. As a result, the

backhaul communication units

26a, 26b, and 26c are exclusively connected to the mobile communication networks MNa, MNb, and MNc, respectively. The SIM may be detachably configured in each backhaul communication unit 26 in the form of a SIM card which is hardware, or may be configured to set an arbitrary identification information IDx as software eSIM (embedded SIM). It may have been done.

SIM cards are provided in various forms such as standard SIM, microSIM, and nanoSIM. By replacing the SIM card to which a different identification information ID is assigned, it is possible to change the connection destination to a different mobile communication network MN.

When applying eSIM, for example, it is attached to the card reader of the backhaul communication unit 26 as a rewritable memory card. The identification information ID can be downloaded from a remote location to the memory card of the corresponding backhaul communication unit 26. For example, the identification information IDa is downloaded to the memory card of the backhaul communication unit 26a. By this operation, the backhaul communication unit 26a is set to exclusively connect to the mobile communication network MNa. According to eSIM, even if a specific identification information IDx is once downloaded to a memory card and connected exclusively to the mobile communication network MNx, another identification information IDy is later downloaded and rewritten to be a different mobile. It can be changed to connect exclusively to the communication network MNy.

Next, the basic functions of the division / integration unit 24 will be described with reference to FIG. FIG. 5 is a schematic diagram illustrating the basic operation of the division / integration unit 24. As shown in FIG. 5, the division / integration unit 24 is provided between the access communication unit 22 and the plurality of backhaul communication units 26.

The division / integration unit 24 supplies the uplink data provided by the access communication unit 22 to the backhaul communication unit 26x that establishes the backhaul communication path BHx associated with the identification information IDx included in the uplink data. To do. Specifically, the identification information determination unit 242 of the division / integration unit 24 refers to the identification information IDx included in the uplink data. Then, the block of the packet data to which the identification information IDx is attached is supplied to the corresponding backhaul communication unit 26x. By this operation, the integrated data CD is sorted into the divided data SD for each mobile communication carrier.

Further, the division / integration unit 24 sequentially supplies downlink data from one or more backhaul communication paths BH to the access communication unit 22. Specifically, the packet data received and transferred by the backhaul communication unit 26 is integrated for each block in the order of arrival to generate an integrated data CD. By this operation, the blocks of packet data individually transmitted from each mobile communication carrier are integrated.

The cells formed by the relay device 20 configured as described above are bases existing in the vicinity due to reasons such as a narrow frequency band in the relay device 20, congestion in communication between the terminal device 10 and the backhaul, and generation of weak electricity. Throughput may be lower than in station cells.

In this case, the relay device 20, carrier aggregation (CA: C arrier A ggregation) application (execution) to. Carrier aggregation is a technology for bundling radio waves (carriers) in a plurality of frequency bands for communication. In carrier aggregation, cells to ensure the connection between the terminal device 10 and the core network 70, primary cell: also called (PCell P rimary Cell). Further, in carrier aggregation, a cell that provides radio resources in addition to the primary cell is also called a secondary cell (SCell: S econdary Cell). The first frequency band used in the primary cell and the second frequency band used in the secondary cell may be the same or different frequency bands from each other.

When performing the carrier aggregation between a plurality of base stations with a delay in the backhaul, dual connectivity: Apply (DC D ual C onnectivity) technology. The specifications of dual connectivity, which bundles radio waves (carriers) between different base stations, are specified in Release 12 of 3GPP. Dual connectivity is the master base station (MeNB: M aster- eNB) and a secondary base station: using a radio resource (SeNB S econdary- eNB) and two base stations called. Therefore, the UCI (U plink C ontrol I nformation ) and scheduling request the primary cell of the master base station receives, it may be difficult to be reflected in real time to a secondary base station via the backhaul. Therefore, in the dual connectivity, it is stipulated that the UCI and the scheduling request are transmitted from the terminal device 10 to one cell under the control of the secondary base station in addition to the primary cell. This cell is a primary secondary cell (PSCell: P rimary SCell) also called. Dual connectivity can also allow simultaneous communication between cells under the same base station. The control of the secondary cell is performed by the primary cell when the secondary cell is under the control of the master base station, and is performed by the primary secondary cell when the secondary cell is under the control of the secondary base station. In the following, for the sake of simplicity, the secondary cell shall be under the control of the master base station, unless otherwise specified.

Next, with reference to FIG. 6, the schematic operation of carrier aggregation by the terminal device 10 and the relay device 20 will be described. FIG. 6 is a flowchart illustrating a schematic operation of carrier aggregation by the terminal device 10 and the relay device 20.

For example, when the terminal device 10 establishes an RRC connection in the radio resource control (RRC: Radio Resource Control) layer via the relay device 20 and camps on the cell constructed by the access communication unit 22, the terminal device 10 and the relay are relayed. The device 20 executes the CA process S300 shown in FIG.

Before executing the CA process S300, or in parallel or in parallel with the execution of the CA process S300, the relay device 20 uses the radio wave (carrier) of the first cell for access communication with the terminal device 10 by the above-mentioned function. The unit 22 communicates. The first cell is a cell formed by the relay device 20.

First, the relay device 20 transmits the cell identification information of the second cell to the terminal device 10 camped on in the first cell formed by the relay device 20 to notify the terminal device 10 (S301). The second cell is a cell different from the first cell described above. The cell identification information is information that associates a cell with a base station that forms the cell, such as a cell ID. The number of cell identification information transmitted to the terminal device 10 is not limited to one, and may be plural.

Next, the relay device 20 determines whether or not the terminal device 10 has detected the second cell identified by the cell identification information notified in step S301 (S302). The relay device 20 receives a report indicating cell detection from the terminal device 10, and determines based on the received report. The report includes cell identification information of cells detected by the terminal device 10. The relay device 20 repeats the determination in step S302 until the terminal device 10 detects the second cell identified by the cell identification information notified in step S301.

As a result of the determination in step S302, when the terminal device 10 detects the second cell identified by the cell identification information notified in step S301, the relay device 20 uses the radio wave (carrier) of the second cell to perform the second cell. The terminal device 10 is instructed to communicate with the base station associated with the identification information of the two cells (S303). The relay device 20 transmits a communication instruction including the identification information of the second cell detected by the terminal device 10 to the terminal device 10 to notify the terminal device 10. As a result, communication using the second cell with the base station associated with the identification information of the second cell is instructed.

For example, in the configuration shown in FIG. 1, the relay device 20 that communicates with the terminal device 10a using the radio wave (carrier) of the first cell executes the CA process S300, so that the terminal device 10a is the relay device 20. And the donor cell base station 30a or the macro cell base station 35a can communicate with each other using the radio wave (carrier) of the second cell.

In this way, the terminal device 10 and the relay device 20 can realize carrier aggregation using two cells including the access communication unit 22, and can improve the communication speed and realize stable high-speed communication. Can be done.

For the sake of simplicity, an example of carrier aggregation using radio waves (carrier waves) in two frequency bands has been shown, but the description is not limited to this. For example, the relay device 20 may execute carrier aggregation using radio waves (carriers) of three or more cells.

The terminal device 10 and the relay device 20 need to hold the cell identification information of the second cell in advance in order to execute the CA process S300 shown in FIG. Further, when the relay device 20 relays the communication between the donor cell base station 30 and the terminal device 10 using the radio wave (carrier) of the first cell, the communication using the radio wave (carrier) of the second cell and the frame. It is necessary to synchronize the timing of.

Next, the software configuration of the control unit 200 will be described with reference to FIG. 7. FIG. 7 is a configuration diagram illustrating the software configuration of the control unit 200.

As shown in FIG. 7, the control unit 200 has a management unit 211, a communication quality information acquisition unit 212, a determination unit 213, a notification unit 214, a synchronization information acquisition unit 215, and a timing control unit as its functional configuration. 216 and.

With the above-mentioned components, the relay device 20 of the present embodiment is configured to be able to carry out the following relay method of relaying the communication between the donor cell base station 30 and the terminal device 10 using the first cell.
(1) A step of managing the registration of cell identification information for associating a cell with a base station forming the cell, and a step of registering cell identification information of a second cell different from the first cell (management unit 211).
(2) A step of notifying the terminal device 10 of the cell identification information of the second cell (notification unit 214).
(3) A step of acquiring synchronization information for synchronizing with communication using the second cell between the base station and the terminal device 10 associated with the cell identification information of the second cell (synchronization information acquisition unit 215).
(4) A step of controlling the timing of the frame when relaying the communication from the donor cell base station 30 to the terminal device 10 based on the synchronization information (timing control unit 216).

The components that execute each step will be explained in detail below.

The management unit 211 is configured to manage the registration of cell identification information that associates a cell with a base station forming the cell. Further, the management unit 211 is configured to register the cell identification information of the second cell. The cell identification information of the second cell to be registered is stored in, for example, the memory 202 or the storage unit 204. The cell identification information of the second cell to be registered is not limited to one, and may be plural. When the second cell is a master base station, that is, a cell formed by the donor cell base station 30, the management unit 211 stores the cell identification information of the second cell as SCell Index, and the second cell is the secondary base station. That is, in the case of a cell formed by a base station other than the donor cell base station 30, the management unit 211 stores the cell identification information of the second cell as PSCell Index.

The cell identification information of the second cell registered by the management unit 211 is registered in units or groups of PLMN, for example, for each PLMN number. As a result, the cell identification information of the second cell, which is different for each mobile communication carrier, can be registered. In addition, the management unit 211 may periodically review the cell identification information of the second cell to be registered. For example, the management unit 211 is a cell of a specific cell such as a cell that has not been used in a predetermined time, a cell that has become less than a predetermined communication quality, a cell formed by the donor cell base station 30, and a cell listed in a blacklist. The identification information may be deleted from the registered cell identification information of the second cell.

The second cell in which the management unit 211 registers the cell identification information is selected from among a plurality of existing cells by applying, for example, at least one of the following first to fourth methods.

(First method)
First, a first method of selecting a base station will be described with reference to FIGS. 8 and 9. FIG. 8 is a schematic diagram illustrating an example of the first method of selecting the second cell. FIG. 9 is a schematic diagram illustrating another example of the first method of selecting the second cell.

The first method is a method of selecting the second cell based on the communication quality. The communication quality information acquisition unit 212 is configured to acquire communication quality information related to the communication quality of the cell associated with the cell identification information. Specifically, as shown in FIG. 8, for example, the communication quality information acquisition unit 212 performs Network Listing, searches for cells around the relay device 20, and acquires communication quality information of each cell. The communication quality information acquisition unit 212, for example, as shown in FIG. 9, the MR (M easurement R eport) to the terminal device 10 located in the cell to which the relay device 20 is formed to perform received from the terminal device 10 , Acquire the communication quality information of the cell in which the terminal device 10 is located. Communication quality information, for example, RSRP (R eference S ignal R eceived P ower), RSSI (R eceived S ignal S trength I ndicator), RSRQ (R eference S ignal R eceived Q uality), SINR (S ignal to I nterference is a plus N oise R atio) and the like.

The determination unit 213 is configured to determine whether or not to register the cell identification information of the cell from which the communication quality information has been acquired, based on the communication quality information. Specifically, the determination unit 213 compares the communication quality indicated by the communication quality information with a predetermined standard, determines that the cell identification information is registered when the quality is equal to or higher than the predetermined quality, and determines that the cell identification information is registered when the quality is lower than the predetermined quality. It is determined that the cell identification information is not registered. Then, the management unit 211 registers the cell identification information as the cell identification information of the second cell according to the determination result of the determination unit 213. As a result, the relay device 20 can use a cell having a communication quality of a predetermined quality or higher as the second cell.

(Second method)
Next, a second method of selecting the second cell will be described with reference to FIG. FIG. 10 is a schematic diagram illustrating a second method of selecting the second cell.

The second method is a method of selecting cell identification information of cells stored in NRT (Neighbor Relation Table). The NRT is stored in, for example, the memory 202 or the storage unit 204, and mainly stores the information of the handover destination candidate of the terminal device 10. The relay device 20 stores information on cells formed in the vicinity of the relay device 20 in the NRT, and the NRT includes cell identification information. Further, the relay device 20 periodically reviews and updates the cell identification information stored in the NRT.

The management unit 211 registers the cell identification information of the cell stored in the NRT as the cell identification information of the second cell. For example, as shown in FIG. 10, "Cell A" is stored in the NRT as the cell identification information of the cell formed by the macro cell base station 35A, and "Cell B" is stored in the NRT as the cell identification information of the cell formed by the macro cell base station 35B. If so, the management unit 211 stores "Cell A" and "Cell B" in SCell Index. As a result, the cell formed in the vicinity of the relay device 20 can be used as the second cell.

(Third method)
Next, a third method of selecting the second cell will be described with reference to FIG. FIG. 11 is a schematic diagram illustrating a third method of selecting the second cell.

The third method is a method of selecting a cell of a donor cell base station.

The management unit 211 registers the cell identification information of the cell formed by the donor cell base station as the cell identification information of the second cell. For example, as shown in FIG. 11, the management unit 211 stores the cell identification information “DeNB Cell” of the donor cell base station 30 in the SCell Index. As a result, the cell formed by the donor cell base station 30 can be used as the second cell.

(Fourth method)
Next, a fourth method of selecting the second cell will be described with reference to FIGS. 12 and 13. FIG. 12 is a schematic diagram illustrating an example of a fourth method of selecting the second cell. FIG. 13 is a schematic diagram illustrating another example of the fourth method of selecting the second cell.

The fourth method is a method of selecting a cell associated with the cell identification information possessed by the donor cell base station.

Similar to the relay device 20, the donor cell base station 30 performs Network Listing to search for surrounding cells, receives MR executed by the terminal device 10 in the donor cell, and the like from the terminal device 10. The cell identification information of the cell obtained by is stored in SCell Index or PSCell Index. Further, the donor cell base station 30 stores the cell identification information of the cells formed in the vicinity in the NRT.

The management unit 211 of the relay device 20 registers these cell identification information received from the donor cell base station 30 as the cell identification information of the second cell. For example, as shown in FIG. 12, "Cell A" is the cell identification information of the cell formed by the macro cell base station 35A, and "Cell B" is the cell identification information of the cell formed by the macro cell base station 35B. When stored in 30 SCell Indexes, the management unit 211 receives these cell identification information and stores "Cell A" and "Cell B" in, for example, SCell Index. Further, as shown in FIG. 13, "Cell A" is used as the cell identification information of the cell formed by the macro cell base station 35A, and "Cell B" is used as the cell identification information of the macro cell base station 35B in the NRT of the donor cell base station 30. When stored, the management unit 211 receives these cell identification information and stores "Cell A" and "Cell B" in, for example, SCell Index. As a result, the cell associated with the cell identification information of the donor cell base station 30 can be used as the second cell.

Returning to the explanation of FIG. 7, the notification unit 214 is configured to notify the terminal device 10 of the identification information of the second cell. The identification information of the second cell notified by the notification unit 214 is registered by the management unit 211. When there are a plurality of cell identification information of the second cell registered by the management unit 211, the notification unit 214 transmits each of the plurality of identification information of the second cell to the terminal device 10 to notify the terminal device 10. In this case, the notification unit 214 may transmit the identification information of the plurality of second cells at once, or may transmit the identification information in several times. Further, the timing at which the notification unit 214 notifies the terminal device 10 of the identification information of the second cell is, for example, when the terminal device 10 camps on the first cell formed by the access control unit 22 of the relay device 20. The cell identification information of the second cell is transmitted to the terminal device 10 to notify the terminal device 10. By notifying the terminal device 10 of the identification information of the second cell in this way, the terminal device 10 uses the radio wave (carrier) of the second cell in addition to the radio wave (carrier) of the first cell by the relay device 20. It becomes possible to carry out the carrier aggregation that was present. Therefore, as compared with the case where only the first cell is used, it is possible to suppress a decrease in throughput and maintain a throughput equivalent to that of a cell formed by a base station existing in the vicinity.

The notification unit 214 is configured to notify the terminal device 10 of an instruction so as to perform communication using the radio wave (carrier) of the second cell with the base station associated with the identification information of the second cell. May be good. The notification of the instruction by the notification unit 214 is, for example, when a report indicating that the terminal device 10 has detected the second cell is received from the terminal device 10, the instruction is transmitted and notified.

The synchronization information acquisition unit 215 is configured to acquire synchronization information. The synchronization information is information for synchronizing with the communication using the second cell between the base station and the terminal device 10 associated with the cell identification information of the second cell.

More specifically, the synchronization information acquisition unit 215 is configured to acquire propagation delay time information as the synchronization information described above. The propagation delay time information is information indicating the propagation delay time in communication with a predetermined base station.

The timing control unit 216 is configured to control the timing of the frame when relaying the communication from the donor cell base station 30 to the terminal device 10 based on the synchronization information. As a result, it becomes possible to synchronize the communication between the base station and the terminal device 10 associated with the cell identification information of the second cell using the second cell. Therefore, it is possible to execute carrier aggregation in which the radio wave (carrier) of the first cell and the radio wave (carrier) of the second cell are synchronized by the relay device 20.

More specifically, the timing control unit 216 is configured to advance the frame timing when relaying the communication from the donor cell base station 30 to the terminal device 10 based on the propagation delay time information.

Specifically, the synchronization information acquisition unit 215 acquires propagation delay time information by performing NDT (Network Derived Timing) with a predetermined base station. That is, in the NDT, the base station transmits a TA (T iming A dvance) Command to the relay device 20. The TA Command includes information on the total delay time between the downlink and the uplink between the base station and the relay device 20, and the synchronization information acquisition unit 215 extracts this information from the received TA Command. Get the propagation delay time information with.

The timing control unit 216 calculates, for example, a value of 1/2 of the propagation delay time information acquired by the synchronization information acquisition unit 215. Then, the timing control unit 216 advances the frame timing by the calculated value in the downlink that relays the communication from the donor cell base station 30 to the terminal device 10 using the radio wave (carrier) of the first cell. In this way, by advancing the frame timing when relaying the communication from the donor cell base station 30 to the terminal device 10 based on the propagation delay time information, the delay time due to propagation can be reflected in the frame timing control. It can be easily synchronized with the communication using the second cell.

In the above description, the timing control unit 216 has shown an example of calculating a value of 1/2 of the propagation delay time information, but the present invention is not limited to this. For example, a base station that performs NDT is, time division duplex (TDD: T ime D ivision D uplex) As such -LTE, the communication system propagation delay time of downlink and uplink are the same, the propagation delay time It calculates a 1/2 of the information, the base station performing the NDT is a frequency division duplex: as such (FDD F requency D ivision D uplex ) -LTE, the propagation delay time of the downlink and uplink are different In the communication system, the timing control unit 216 may advance the timing of the communication frame by using another value or another method. For example, when the base station to perform NDT is the FDD-LTE communication system, the relay device 20 may search for the base station of the TDD-LTE communication system and change the base station to be NDT. Alternatively, synchronization information other than propagation delay time information may be acquired by a method other than NDT. Further, the timing control unit 216 approximates the delay of the communication frame in the downlink with a value of 1/2 of the propagation delay time information, or approximates it from the time information based on the clocks of the base station and the relay device 20. The deviation may be allowed.

Next, a predetermined base station in which the synchronization information acquisition unit 215 performs NDT will be described with reference to FIGS. 14 to 16. FIG. 14 is a schematic diagram illustrating an example of the operation of the synchronization information acquisition unit 215. FIG. 15 is a schematic diagram illustrating another example of the operation of the synchronization information acquisition unit 215. FIG. 16 is a schematic diagram illustrating still another example of the operation of the synchronization information acquisition unit 215.

As shown in FIG. 14, when the terminal device 10 communicates with the macro cell base station 35 using the radio wave (carrier) of the second cell, the synchronization information acquisition unit 215 communicates with the donor cell base station 30, for example, NDT. May be performed to acquire propagation delay time information.

Further, as shown in FIG. 15, when the terminal device 10 communicates with the macro cell base station 35 using the radio wave (carrier) of the second cell, the synchronization information acquisition unit 215 is, for example, the macro cell base station 35 which is a SCell. NDT may be performed with and to acquire the propagation delay time information.

Further, as shown in FIG. 16, when the terminal device 10 communicates with the macro cell base station 35 using the radio wave (carrier) of the second cell, the synchronization information acquisition unit 215 is, for example, a macro cell base station existing in the vicinity. NDT may be performed with 35B to acquire propagation delay time information.

In the above description, an example is shown in which there is one predetermined base station that performs NDT, but the present invention is not limited to this. For example, the synchronization information acquisition unit 215 may perform NDT with a plurality of base stations. In this case, the synchronization information acquisition unit 215 may calculate the average value or the median value in the total delay time of the plurality of downlinks and uplinks extracted from each TA Command. Further, the base station performing NDT may be limited to a base station having the same PLMN number as the PLMN performing carrier aggregation, with the PLMN as a unit or a group. Further, as the base station that performs NDT, a base station having good communication quality, for example, RSRP or the like may be selected to have a predetermined value or more, or a base station having a specific PLMN number or a base station forming a specific cell is selected. You may.

[Second Embodiment]
<Relay system>
Next, a relay system according to the second embodiment of the present invention will be described with reference to FIGS. 17 to 19. The same or similar reference numerals are given to the same or similar configurations as those in the first embodiment. Hereinafter, the points different from the first embodiment will be described. In addition, similar actions and effects with the same configuration will not be mentioned sequentially.

First, the configuration of the relay system according to the second embodiment of the present invention will be described with reference to FIG. FIG. 17 is a schematic diagram schematically showing the configuration of the relay system 400 according to the second embodiment.

As shown in FIG. 17, the relay system 400 includes a relay device 20A and a base station management device 410.

The base station management device 410 provides cell identification information for associating a cell formed by the base station with the base station and position information indicating the position of the base station for each of the plurality of base stations managed by the device. It is configured to manage. The position information is, for example, latitude and longitude information. In the example shown in FIG. 17, the base station management device 410 stores the cell identification information and the position information of the donor cell base station 30, and the cell identification information and the position information of the macro cell base station 35A.

Further, when the base station management device 410 receives a request from the relay device 20A, the base station management device 410 responds to the request with cell identification information of a cell formed by the base station within a predetermined distance from the position of the relay device 20. It is configured. In the example shown in FIG. 17, the relay device 20A is configured to acquire location information from the GPS (G lobal P ositioning S ystem ) satellite GS. The position information is, for example, latitude and longitude information as in the above-described example. The request from the relay device 20A includes the position information acquired from the GPS satellite GS. The base station management device 410 transmits the cell cell identification information of each of the donor cell base station 30 and the macro cell base station 35A located within the radius RA from the position indicated by the position information to the relay device 20A.

The base station management device 410 stores the identification information and the position information of the relay device 20A in advance, refers to the position information of the relay device 20A in response to the request from the relay device 20A, and indicates the referenced position information. The cell identification information of each of the donor cell base station 30 and the macro cell base station 35A located within the radius RA from the position may be transmitted to the relay device 20A.

Next, the software configuration of the control unit of the relay device according to the second embodiment will be described with reference to FIG. FIG. 18 is a configuration diagram illustrating the software configuration of the control unit 200A.

As shown in FIG. 18, the control unit 200A of the second embodiment replaces the management unit 211, the synchronization information acquisition unit 215, and the timing control unit 216 with the management unit 211A, the synchronization information acquisition unit 215A, and the timing control unit 216A. It is different from the control unit 200 of the first embodiment in that the control unit 200 is provided.

For example, the management unit 211A transmits a request including position information acquired from the GPS satellite GS to the base station management device 410. Then, the management unit 211A receives the response from the base station management device 410.

Further, the management unit 211A is configured to register the cell identification information included in the response from the base station management device 410 as the cell identification information of the second cell. As a result, the cell formed by the base station within a predetermined range from the position of the relay device 20 can be used as the second cell.

Next, the operation of the synchronization information acquisition unit 215A will be described with reference to FIG. FIG. 19 is a schematic diagram illustrating the operation of the synchronization information acquisition unit 215A.

The synchronization information acquisition unit 215A is configured to acquire time information from a GPS transmitter as synchronization information. For example, as shown in FIG. 19, the synchronization information acquisition unit 215A receives and acquires time information from the GPS satellite GS. Similarly, the macrocell base station 35A also receives time information from the GPS satellite GS. The macrocell base station 35A operates based on the time information. FIG. 19 shows an example of receiving time information from the GPS satellite GS, but the present invention is not limited to this. For example, in order to acquire more accurate time, the synchronization information acquisition unit 215A may receive and acquire time information from each of a plurality of GPS satellites.

The timing control unit 216A is configured to advance the frame timing when relaying the communication from the donor cell base station 30 to the terminal device 10 based on the time information. In this way, by accelerating the frame timing when relaying the communication from the donor cell base station 30 to the terminal device 10 based on the time information acquired from the GPS satellite GS, the macro cell base station 35A that operates with the same time information And, the frame timing can be easily synchronized.

[Third Embodiment]
<Relay system>
Next, a relay system according to the third embodiment of the present invention will be described with reference to FIGS. 20 to 22. The same or similar reference numerals are given to the same or similar configurations as those in the first embodiment. Hereinafter, the points different from the first embodiment will be described. In addition, similar actions and effects with the same configuration will not be mentioned sequentially.

First, the configuration of the relay system according to the third embodiment of the present invention will be described with reference to FIG. FIG. 20 is a schematic diagram schematically showing the configuration of the relay system 500 according to the second embodiment.

As shown in FIG. 20, the relay system 500 includes a relay device 20B and a time management device 510.

The time management device 510 is configured to supply reference time information indicating a reference time to each of a plurality of base stations managed by the device. The time management device 510 includes, for example, a GMC (Grandmaster Clock) that supplies a highly accurate time. In the example shown in FIG. 20, reference time information is supplied to each of the time management device 510, the donor cell base station 30, and the macro cell base station 35A. Further, as will be described later, the time management device 510 also supplies the reference time information to the relay device 20B.

Next, with reference to FIG. 21, the software configuration of the control unit of the relay device according to the third embodiment will be described. FIG. 21 is a configuration diagram illustrating the software configuration of the control unit 200B.

As shown in FIG. 21, the control unit 200B of the second embodiment includes the synchronization information acquisition unit 215B and the timing control unit 216B in place of the synchronization information acquisition unit 215 and the timing control unit 216. It is different from the control unit 200.

The synchronization information acquisition unit 215B is configured to acquire the reference time information supplied by the time management device 510 as the synchronization information.

Next, the operation of the timing control unit 216B will be described with reference to FIG. FIG. 22 is a schematic diagram illustrating the operation of the timing control unit 216B.

The timing control unit 216B relays the communication from the donor cell base station 30 to the terminal device 10 based on the deviation time from the reference time and the propagation delay time in the communication with the time management device 510 calculated from the reference time information. It is configured to accelerate the timing of the time frame. Propagation delay time in communication with the time lag and the time management unit 510 with the reference time, for example, NTP (N etwork T ime P rotocol ), it is calculated using the PTP (P recision T ime P rotocol ) or the like. Specifically, when the time management device 510 is the master and the relay device 20B is the slave, for example, as shown in FIG. 22, when the master and the slave are asynchronous, the respective reference times T0. There is a gap between them. In the example shown in FIG. 22, the slave time Ts is advanced by Offset from the master time Tm. The slave receives a Sync message in which the time Tm1 is stamped from the master at the time Ts2, and compares the time Ts2 with the time Tm1. As a result, the value α (= Ts2-Tm1) shown in FIG. 22 is calculated. Next, the slave sends a Sync message to the master at time Ts3, and the master records the time Tm4 at which the Sync message is received. Then, the slave receives the Sync message including the time Tm4 from the master, and compares the time Tm4 with the time Ts3. As a result, the value β (= Tm4-Ts3) shown in FIG. 22 is calculated.

Here, assuming that the delay time DL Delivery of the downlink from the master to the slave and the delay time UL Delivery of the uplink from the slave to the master are the same, the reference time of the relay device 20B and the time management device 510 The deviation time Offset from the reference time is expressed by the following equation (1) using the value α and the value β.
Offset = (α-β) / 2 ... (1)

Similarly, the propagation delay time Delay in the communication between the relay device 20B and the time management device 510 is expressed by the following equation (2) using the values α and β.
Delay = (α + β) / 2 ... (2)

In this way, from the donor cell base station 30 to the terminal device 10 based on the time shift time Offset from the reference time of the time management device 510 and the propagation delay time Delivery in the communication with the time management device 510 calculated from the reference time information. By accelerating the frame timing when relaying the communication of, the frame timing can be easily synchronized with the macro cell base station 35A based on the same reference time information.

The exemplary embodiments of the present invention have been described above. According to the relay device 20 and the relay method according to the first embodiment, the identification information of the second cell is notified to the terminal device 10. As a result, the terminal device 10 can perform carrier aggregation using the radio waves (carriers) of the second cell in addition to the radio waves (carriers) of the first cell by the relay device 20. Therefore, as compared with the case where only the first cell is used, it is possible to suppress a decrease in throughput and maintain a throughput equivalent to that of a cell formed by a base station existing in the vicinity. Further, based on the synchronization information, the timing of the frame when relaying the communication from the donor cell base station 30 to the terminal device 10 is controlled. As a result, it becomes possible to synchronize the communication between the base station and the terminal device 10 associated with the cell identification information of the second cell using the second cell. Therefore, it is possible to execute carrier aggregation in which the radio wave (carrier) of the first cell and the radio wave (carrier) of the second cell are synchronized by the relay device 20.

Further, according to the relay system 400 according to the second embodiment, the cell identification information included in the response from the base station management device 410 is registered as the cell identification information of the second cell. As a result, the cell formed by the base station within a predetermined range from the position of the relay device 20 can be used as the second cell.

Further, according to the relay system 500 according to the third embodiment, the deviation time Offset from the reference time of the time management device 510 and the propagation delay time Delay in the communication with the time management device 510 calculated from the reference time information are used. , The timing of the frame when relaying the communication from the donor cell base station 30 to the terminal device 10 is accelerated. As a result, the frame timing can be easily synchronized with the macro cell base station 35A based on the same reference time information.

It should be noted that each of the embodiments described above is for facilitating the understanding of the present invention, and is not for limiting and interpreting the present invention. The present invention can be modified / improved without departing from the spirit thereof, and the present invention also includes an equivalent thereof. That is, those skilled in the art with appropriate design changes to each embodiment are also included in the scope of the present invention as long as they have the features of the present invention. For example, each element included in the embodiment and its arrangement, material, condition, shape, size, and the like are not limited to those exemplified, and can be changed as appropriate. Moreover, the embodiment is an example, and it goes without saying that the configurations shown in different embodiments can be partially replaced or combined, and these are also included in the scope of the present invention as long as the features of the present invention are included.

10, 10a, 10b, 10c ... Terminal device, 20, 20A, 20B ... Relay device, 22 ... Access communication unit, 24 ... Divisional integration unit, 26, 26a, 26b, 26c, 26x ... Backhole communication unit, 30, 30a , 30b, 30c ... Donor cell base station, 35, 35A, 35B, 35a, 35b ... Macrocell base station, 40, 40a 1st core network, 50, 50a, 50b ... Virtual base station device, 60, 60a ... 2nd core network , 70 ... core network, 80 ... external network, 100 ... mobile communication system, 200, 200A, 200B ... control unit, 201 ... processor, 202 ... memory, 204 ... storage unit, 206 ... interface circuit, 210 ... interface circuit, 211, 211A ... Management unit, 212 ... Communication quality information acquisition unit, 213 ... Judgment unit, 214 ... Notification unit, 215, 215A, 215B ... Synchronous information acquisition unit, 216, 216A, 216B ... Timing control unit, 222 ... Antenna, 242 ... Identification information determination unit, 262 ... Antenna, 400 ... Relay system, 410 ... Base station management device, 500 ... Relay system, 510 ... Time management device, Delay ... Propagation delay time, GS ... GPS satellite, Offset ... Deviation time, RA ... radius, S300 ... CA processing.

Claims

A relay device that relays communication between a donor cell base station and a terminal device using the first cell.
A management unit that manages the registration of cell identification information that associates a cell with a base station that forms the cell, and a management unit that registers the cell identification information of a second cell different from the first cell.
A notification unit that notifies the terminal device of the cell identification information of the second cell, and
A first acquisition unit that acquires synchronization information for synchronizing with communication using the second cell between the base station and the terminal device associated with the cell identification information in the second cell.
A timing control unit that controls the timing of a frame when relaying communication from the donor cell base station to the terminal device based on the synchronization information is provided.
Relay device.
A second acquisition unit that acquires communication quality information related to the communication quality of the cell associated with the cell identification information, and
Further, a determination unit for determining whether or not to register the cell identification information based on the communication quality information is provided.
The management unit registers the cell identification information as the cell identification information of the second cell according to the result of the determination.
The relay device according to claim 1.
The management unit registers the cell identification information of the cell formed in the vicinity of the relay device as the cell identification information of the second cell.
The relay device according to claim 1 or 2.
The management unit registers the cell identification information of the cell formed by the donor cell base station as the cell identification information of the second cell.
The relay device according to any one of claims 1 to 3.
The management unit registers the cell identification information received from the donor cell base station as the cell identification information of the second cell.
The relay device according to any one of claims 1 to 4.
The first acquisition unit acquires the propagation delay time information indicating the propagation delay time in communication with a predetermined base station as the synchronization information.
The timing control unit advances the timing of the frame when relaying the communication from the donor cell base station to the terminal device based on the propagation delay time information.
The relay device according to any one of claims 1 to 5.
The first acquisition unit acquires time information from the GPS transmitter as the synchronization information, and obtains time information.
The timing control unit advances the timing of the frame when relaying the communication from the donor cell base station to the terminal device based on the time information.
The relay device according to any one of claims 1 to 5.
This is a relay method for relaying communication between a donor cell base station and a terminal device using the first cell.
A step of managing the registration of cell identification information for associating a cell with a base station forming the cell, and a step of registering the cell identification information of a second cell different from the first cell.
A step of notifying the terminal device of the cell identification information of the second cell, and
A step of acquiring synchronization information for synchronizing with communication using the second cell between the base station and the terminal device associated with the cell identification information of the second cell, and
A step of controlling the timing of a frame when relaying communication from the donor cell base station to the terminal device based on the synchronization information is included.
Relay method.
A relay device that relays communication between the donor cell base station and the terminal device using the first cell,
A base station management device that manages cell identification information for associating a cell formed by the base station with the base station and position information indicating the position of the base station for each of the plurality of base stations, and is a relay device. A base station management device that responds to the cell identification information of a cell formed by a base station within a predetermined distance from the position of the relay device.
The relay device is
A management unit that manages the registration of the cell identification information, and a management unit that registers the cell identification information in the second cell different from the first cell.
A notification unit that notifies the terminal device of the cell identification information of the second cell, and
An acquisition unit that acquires synchronization information for synchronizing with communication using the second cell between the base station and the terminal device associated with the cell identification information in the second cell.
A timing control unit that controls the timing of a frame when relaying communication from the donor cell base station to the terminal device based on the synchronization information is provided.
The management unit registers the cell identification information included in the response from the base station management device as the cell identification information of the second cell.
Relay system.
A relay device that relays communication between the donor cell base station and the terminal device using the first cell,
A time management device that provides reference time information indicating a reference time to each of a plurality of base stations is provided.
The relay device is
A management unit that manages cell identification information that associates a cell with a base station that forms the cell, and a management unit that registers the cell identification information of a second cell different from the first cell.
A notification unit that notifies the terminal device of the cell identification information of the second cell, and
An acquisition unit that acquires synchronization information for synchronizing with communication using the second cell between the base station and the terminal device associated with the cell identification information in the second cell.
A timing control unit that controls the timing of a frame when relaying communication from the donor cell base station to the terminal device based on the synchronization information is provided.
The acquisition unit acquires the reference time information as the synchronization information, and obtains the reference time information.
The timing control unit performs communication from the donor cell base station to the terminal device based on the deviation time from the reference time and the propagation delay time in the communication with the time management device calculated from the reference time information. Advance the frame timing when relaying,
Relay system.