JP2017011421A - Relay device and communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably prevent a terminal unit of a relay device including the terminal unit for performing radio communication with a radio base station and a base station unit for performing radio communication with a radio terminal from connecting to the base station unit of the relay device or the base station unit of another relay device.SOLUTION: A relay device includes a terminal unit for performing radio communication with a radio base station and a base station unit for performing radio communication with a radio terminal, and relays radio communication between the radio base station and the radio terminal. The base station unit transmits base station information allocated to the base station unit of the relay device in advance by using a system information block that transmits base station information in a notification signal. The terminal unit receives base station information in the system information block in the notification signal about a base station including the base station unit which the terminal unit can receive a signal from, checks the base station information with the pre-stored base station information allocated to the base station unit of the relay device, and excludes the base station having transmitted the base station information from a connection destination candidate if they accord.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a technology for relaying communication between a radio base station and a radio terminal.

  With the widespread use of wireless terminals such as mobile phones and data communication terminals, users are increasingly required to provide easier communication connections and higher-speed wireless communication services. The wireless terminal can communicate only within an area covered by radio waves transmitted by the wireless base station, and cannot communicate outside the covered area of the wireless base station. For this reason, each wireless communication carrier company designs the area, installs a wireless base station so that radio waves from the wireless base station do not reach and can not go out of the cover area, improve the quality of the wireless communication service area, The area where communication services are provided is being expanded.

  Examples of places where radio waves from radio base stations are difficult to reach include indoors and underground buildings. These places are places where radio waves from a macrocell base station (area radius of several hundred meters to several kilometers) that covers a wide area are difficult to reach. In order to provide a wireless communication service in such a place, installation of small base stations (femtocell base stations (area radius is several meters to several tens of meters)) is being promoted. A small base station has a small area covered by a single base station. Generally, a large number of wireless base station devices are placed indoors or underground in a building, so a wired backhaul line is required for each device. Therefore, the cost is high due to the laying work.

  As a method to easily expand the area or improve the quality of the area without the need for construction work of laying a wired backhaul line, install a relay device that relays radio base station radio waves to areas where radio waves are difficult to reach There is a way. The relay device relays signals by connecting a wireless line to each of the wireless base station and wireless terminal, so there is no need to lay a wired backhaul line, such as indoors or underground in a building without any line laying work. The radio wave condition of can be improved.

  The relay device includes a terminal unit having a function of performing communication by connecting to a radio base station via a radio channel, and a base station unit performing communication by connecting to a radio terminal via a radio channel. If the terminal unit of the relay device mistakenly connects wirelessly with the base station unit of its own device, the data loops between the terminal unit and the base station unit, and the relay of data cannot be performed. It is necessary to make it so that the terminal unit in the own device and the base station unit are not connected. One method is to configure the system so that the communication of the base station part of the relay apparatus is performed at a frequency different from the communication frequency of the other radio base station, and the terminal part of the relay apparatus has a frequency different from the base station part of the own apparatus. By performing communication with the terminal device, it is possible to prevent the terminal unit of the relay device from connecting to the base station unit of the own device.

  However, Mobile WiMAX (World Wide Interoperability for Microwave Access) standardized as IEEE 802.16e, and TDD-LTE (Time Division Duplex-LongTurm territory that performs standardization from 3GPP) In a communication system, when the number of usable channels is small, the radio base station and the base station unit of the relay device may have to communicate at the same frequency, and the wireless connection between the terminal unit of the relay device and the base station unit may occur. Other methods are needed to prevent this.

Although it is not a technique aiming at preventing wireless connection between the terminal unit and the base station part of the relay apparatus, Patent Document 1 discloses a technique for suppressing mutual interference between the base station side communication part and the terminal side communication part of the relay apparatus. And those described in Patent Document 2. In Patent Document 1, the relay device determines the transmission / reception timing of other surrounding relay devices, and sets the transmission / reception timing of the relay device to the normal transmission / reception timing or the inversion timing inverted from the normal transmission / reception timing based on the determination result. To do.
Further, in Patent Document 2, the degree of mutual interference (wraparound interference or self-interference) of the relay device is calculated, and the directivity of at least one of the base station side antenna and the mobile station side antenna is set according to the calculated degree of mutual interference. The antenna directivity adjustment unit is controlled to change.

JP 2013-30935 A JP 2013-74399 A

  Although the technology for suppressing mutual interference described in Patent Document 1 and Patent Document 2 is applicable to the problem that the terminal unit of the relay device described above erroneously wirelessly connects to the base station unit of the own device. When the wireless communication between the terminal side communication unit and the base station side communication unit of the relay device is prevented using the technology of Patent Document 1, the terminal side communication unit of the relay device and the wireless terminal are different in timing from other wireless base stations. Since communication is performed, when a wireless terminal connected to the terminal-side communication unit hands over to another wireless base station, the connection with the currently connected terminal-side communication unit is disconnected and then the handover-destination wireless base station Must be connected with. That is, seamless handover cannot be performed and communication is temporarily disconnected. For this reason, when the relay device is installed in a public facility or the like, there is a possibility that many users will be disconnected during handover.

  In Patent Document 2, the terminal side communication unit and the base station side communication unit are adjusted by adjusting the antenna directivity of the terminal side communication unit or the base station side communication unit to reduce radio wave interference from the terminal side communication unit. However, the wireless connection between the terminal side communication unit and the base station side communication unit cannot be reliably prevented.

  Furthermore, when a plurality of relay devices are installed without securing a sufficient interval, the relay device may be connected to another relay device installed in the vicinity. In this case, the data transmitted from the wireless terminal passes through a plurality of relay apparatuses before reaching the transmission destination. As the number of relay devices that pass through increases, processing relating to wireless connection control and the like occur, and a problem arises in that the throughput of communication data decreases. Neither of the techniques described in Patent Document 1 and Patent Document 2 can prevent a relay device from wirelessly connecting to another relay device.

  The present invention has been made to solve the above-described problem, and a terminal unit having a function of communicating with a wireless base station through a wireless channel is connected to a base station unit of the own device and a base station unit of another relay device. It is an object of the present invention to provide a relay device and a communication method that can reliably prevent connection.

  In order to solve the above problems, in the present invention, as an example, a relay device that relays wireless communication between a base station and a wireless terminal, a terminal unit that performs wireless communication with the base station, and a wireless communication with the wireless terminal The base station unit is a system information block that transmits base station information of a broadcast signal, and is configured to transmit base station information previously assigned to the base station unit of the relay apparatus.

  Each of the base station unit and the terminal unit has a storage unit, and the base station information assigned to the base station unit of the relay device is stored in advance in the storage unit of the base station unit and the storage unit of the terminal unit or via a communication line. Are received and stored.

  In addition, for the base station from which the terminal unit can receive signals, the schedule information of the head block of the system information block of the broadcast signal is scheduled to be transmitted in the system information block for transmitting the base station information. The base station information is received and collated with the base station information assigned to the base station section of the relay device stored in advance, and if they match, the base station that transmitted the base station information is identified from the connection destination candidates. It is something that was removed.

  ADVANTAGE OF THE INVENTION According to this invention, the relay apparatus and communication which can prevent reliably the terminal part which connects and communicates with a wireless base station via a radio | wireless line to the base station part of an own apparatus and the base station part of another relay apparatus A method can be provided.

It is a figure explaining the connection relation of the relay apparatus in one Embodiment of this invention. It is a figure explaining the structure of the relay apparatus in one Embodiment of this invention. It is a sequence diagram explaining the connection procedure of the terminal part of a relay apparatus, and a wireless base station. It is a figure explaining the procedure which the terminal part of a relay apparatus hands over from the radio base station to which it is connected to another radio base station. It is a flowchart explaining the connection process with the radio base station of the relay apparatus in one Embodiment of this invention. It is a flowchart explaining the process until the hand-over start of the terminal part of the relay apparatus in one Embodiment of this invention. It is a flowchart explaining the process from the handover start of the terminal part of the relay apparatus in one Embodiment of this invention to the completion of a handover. It is a figure which shows the structural example of a PCI list.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a connection relationship of a relay device according to an embodiment of the present invention.
In the present embodiment, a case where wireless communication is performed by LTE (Long Term Evolution) will be described as an example. The relay device 100 relays data between the radio base station 200 and the radio terminal 300. In the description of the present embodiment, a base station may be described as a generic term for a radio base station and a base station part of a relay device or as a designation indicating one of them.

  FIG. 2 is a diagram illustrating the configuration of the relay device according to the embodiment of the present invention.

The relay apparatus 100 includes a terminal unit 110 and a base station unit 120.
First, the terminal unit 110 will be described. The terminal unit 110 transmits and receives data to and from the radio base station 200 via an antenna. The radio processing unit 111 of the terminal unit 110 controls radio connection with the radio base station 200, transmits data received from the radio base station 200 to the interface unit 113, and transmits data received from the interface unit 113 to the radio base station 200. Send. The storage unit 112 of the terminal unit 110 stores setting information and parameters necessary for radio connection control with the radio base station 200 and data communication control with the base station unit 120. In the present embodiment, the storage unit 112 stores at least a PCI list 1121 and an HNB Name 1122. The contents and generation method of the PCI list 1121 and the HNB Name 1122 will be described later with reference to FIGS.

  The interface unit 113 of the terminal unit 110 transmits and receives data to and from the interface unit 122 of the base station unit 120 of the relay device 100. In this embodiment, data transmission / reception between the interface unit 113 of the terminal unit 110 and the interface unit 122 of the base station unit 120 is performed via a LAN (Local Area Network) cable. The storage unit 112 of the terminal unit 110 of this embodiment is, for example, a nonvolatile memory.

  Next, the base station unit 120 will be described. The base station unit 120 transmits / receives data to / from the wireless terminal 300 via an antenna. The wireless processing unit 121 of the base station unit 120 controls connection with the wireless terminal 300, transmits data received from the wireless terminal 300 to the interface unit 122 of the base station unit 120, and wireless data of data received from the interface unit 122 of the base station unit 120 Transmission to 300 is performed. Further, the interface unit 122 of the base station unit 120 transmits data received from the radio processing unit 121 of the base station unit 120 to the interface unit 113 of the terminal unit 110 and receives data received from the interface unit 113 of the terminal unit 110. To the wireless processing unit 121. The storage unit 123 of the base station unit 120 stores setting information and parameters necessary for wireless connection control with the wireless terminal 300 and data communication control with the terminal unit 110. In the present embodiment, at least HNB Name 1231 is stored in the storage unit 123. The HNB Name 1231 will be described later with reference to FIGS.

Next, the operation when the radio processing unit 111 of the terminal unit 110 of the relay apparatus 100 connects to the radio base station will be described.
FIG. 3 is a sequence diagram illustrating a connection procedure between the terminal unit of the relay apparatus and the radio base station.
Although FIG. 3 mainly describes the terminal unit 110 of the relay device 100, the connection procedure of the wireless terminal that performs communication based on the LTE standard is a similar sequence. 3 is a wireless base station in the vicinity of the wireless base station 200 and the relay device 100.

  In the sequence diagram of FIG. 3, the terminal unit 110 of the relay device 100 is in a connection waiting state (RRC (Radio Resource Control) IDLE) (S300) that is not connected to any radio base station. The connection waiting state is a connection waiting state from the connection state (RRC CONNECT) before the wireless terminal is initially connected to the wireless base station after the power is turned on or after the wireless terminal is connected to the wireless base station. For example, when returning to

  The terminal unit 110 of the relay apparatus 100 that is in a connection waiting state starts searching for a connectable base station (S301). When scanning is performed on each frequency channel with which the terminal unit 110 can communicate, the synchronization signals S302, S303, and S304 are received from the radio base station 200, the radio base station 400, and the base station unit 120 of the relay apparatus 100 in FIG. The terminal unit 110 of the relay apparatus 100 acquires a synchronization signal (S302, S303, S304), and calculates PCI (Physical Cell Identity) that identifies the radio base station in the physical layer (S305). PCI is a number assigned in advance so that wireless communication carriers do not overlap between neighboring wireless base stations at the time of network design, and has a value from 0 to 503 in the case of an LTE system.

  The terminal unit 110 can extract the reference signal of the base station after calculating the PCI of the base station, and the power of the received signal from each base station with parameters such as the received power of the reference signal (RSRP, Reference Sine Received Power). Confirm. A reference signal is a signal transmitted to measure the power of a signal received by a wireless terminal from a base station. In the example of FIG. 3, it is assumed that the signal from the radio base station 400 has insufficient power (S306).

  On the other hand, the terminal unit 110 of the relay device 100 determines that the power of the received signals from the radio base station 200 and the base station unit 120 of the relay device 100 is sufficient. The terminal unit 110 acquires information blocks (S307 and S308) broadcasted by the radio base station 200 and the base station unit 120 of the relay apparatus 100 (S309). There are two types of information blocks that the terminal unit 110 acquires from the radio base station 200 and the base station unit 120 of the relay apparatus 100.

  One is a master information block (hereinafter referred to as “MIB”), and the terminal unit 110 of the relay apparatus 100 can acquire the MIB of the base station by knowing the PCI of the base station. The MIB includes a bandwidth and a system frame number of a signal received by the terminal unit 110 of the relay apparatus 100 from the base station. Based on this information, the terminal unit 110 is a system information that is another information block. A block (System Information Block, hereinafter referred to as SIB) can be acquired.

  SIBs are transmitted from the base station in the order of information blocks from SIB1 to SIB17. Of these, SIB1 is transmitted at a fixed cycle from all base stations. In addition, since the transmission schedule of information blocks after SIB2 differs depending on the base station, the transmission schedule of SIBs after SIB2 is notified by SIB1. The terminal unit 110 of the relay apparatus 100 acquires system information of the base station from each SIB received from the base station, determines that it is appropriate based on the system information, and selects it as a connection destination candidate base station (S310). Connection processing with the station (S311) is performed, and connection with the base station is performed (S312).

Next, the operation of the radio processing unit 111 of the terminal unit 110 of the relay apparatus 100 when the relay apparatus 100 performs handover between radio base stations will be described.
FIG. 4 is a diagram illustrating a procedure for handing over from a radio base station to which the terminal unit of the relay apparatus is connected to another radio base station. Handover refers to changing a connection destination wireless base station in a state where the wireless terminal is connected to the wireless base station. Although FIG. 4 mainly describes the terminal unit 110 of the relay apparatus 100, the same sequence is applied to a wireless terminal that performs communication based on the LTE standard.

  In FIG. 4, the terminal unit 110 of the relay apparatus 100 is connected to the radio base station 200 (S400). First, the terminal unit 110 of the relay apparatus 100 receives a radio wave power measurement request (S401) of a neighboring base station from the connection-destination radio base station 200, and starts searching for a base station (S402). The terminal unit 110 acquires the synchronization signals (S403 and S404) of the neighboring base stations 400 and 120 and calculates the PCI of the base station (S405) in order to measure the radio wave power of the neighboring base station. The terminal unit 110 then acquires a reference signal, performs power measurement of the reference signal (S406), creates the measurement result, and transmits the measurement result to the radio base station 200 (S407, S408).

  The radio base station 200 determines the handover destination radio base station based on the received measurement result, and confirms the possibility of handover by exchanging messages with the handover destination radio base station based on the LTE standard (S409). And transmits a handover instruction to the terminal unit 110 (S410). In FIG. 4, the radio base station 400 is determined as a handover destination radio base station, and the possibility of handover is confirmed.

  Thereafter, a handover process (S411) is performed by the handover source radio base station 200, the handover destination radio base station 400, and the terminal unit 110 of the relay apparatus 100. In this process, the terminal unit 110 disconnects the communication line with the handover source radio base station 200 and connects to the handover destination radio base station 400. Thereafter, the handover process is completed (S412), and the terminal unit 110 transmits a handover process completion notification (RRC Connection Reconfiguration Complete) to the handover destination radio base station 400 (S413). After receiving the handover process completion notification, the handover destination radio base station 400 and the handover source radio base station 200 perform the handover completion process (S414). If the handover fails, the terminal unit 110 requests the reconnection to the handover source radio base station 200 without notifying the handover destination radio base station 400 of the completion of the handover process. It is possible to connect to the handover source radio base station 200, and as a result, it is possible to maintain the connection state. When the handover completion process (S414) ends, the handover is completed (S415).

  As described above, the wireless terminal or the terminal unit obtains the synchronization signal transmitted by the wireless base station in the connection sequence with the wireless base station in the stage before connection with the wireless base station, calculates the PCI, Furthermore, an information block included in a broadcast signal transmitted by the radio base station can also be received. However, once a wireless terminal or terminal unit is handed over to another wireless base station after connecting to the wireless base station, acquisition of a synchronization signal of the handover destination wireless base station and PCI It can only be done up to the calculation.

  From here, the configuration and processing for preventing the terminal unit 110 of the relay device 100 from being wirelessly connected to the base station unit 120 of the relay device 100 based on the connection with the radio base station and the processing of the handover procedure described above. A connection between the terminal unit 110 including the radio base station and a handover procedure will be described with reference to FIGS.

FIG. 5 is a flowchart illustrating a connection process between a relay apparatus and a radio base station according to an embodiment of the present invention.
FIG. 6 is a flowchart for explaining processing up to the start of handover of the terminal unit of the relay device according to the embodiment of the present invention.
FIG. 7 is a flowchart for explaining processing from the start of handover to the completion of handover of the terminal unit of the relay device in one embodiment of the present invention.
In this embodiment, in order to prevent wireless connection between the terminal unit 110 of the relay device 100 and the base station unit 120, a Home NodeB Name that is arbitrarily transmitted by a small (femtocell) radio base station to the base station unit of the relay device to which the present invention is applied. (Hereinafter, HNB Name) is transmitted, and the terminal unit 110 identifies the base station unit of the relay apparatus and other radio base stations based on this information.

  HNB Name is a parameter transmitted by a small (femtocell) radio base station. A small (femtocell) base station is a closed subscriber group (hereinafter referred to as CSG cell) base station that can be connected only to some wireless terminals or a hybrid cell (hereinafter referred to as hybrid) that provides services preferentially to some wireless terminals. Cell) In the case of a base station, this is a character string that is arbitrarily transmitted by the small radio base station for the purpose of notifying the radio terminal of the group name. However, the base station unit 120 of the relay apparatus 100 is a small base station to which all wireless terminals can be connected, and appears to the wireless terminal 300 in the same manner as a normal wireless base station.

  The wireless terminal identifies that a certain wireless base station is a CSG cell base station or a hybrid cell base station by using two parameters of CSG Indicator and CSG Identity transmitted by the wireless base station. HNB Name is a parameter that is optionally transmitted to allow a user of a wireless terminal to manually select a CSG cell base station or a hybrid cell base station. In the present embodiment, the HNB Name is stored in the storage unit 123 of the base station unit 120 of the relay apparatus 100 and transmitted.

  Since relay apparatus 100 is not a CSG cell base station or a hybrid cell base station, CSG Indicator and CSG Identity are not transmitted. By using this, the terminal unit 110 of the relay device 100 can recognize that the terminal unit 110 of the relay device 100 is the base station unit 120 when only the HNB Name is transmitted without transmitting the CSG Indicator and CSG Identity. . With this configuration, the base station unit 120 of the relay device 100 appears to the general radio terminal 300 as a normal radio base station that is neither a CSG cell base station nor a hybrid cell base station, and the terminal unit 110 of the relay device 100 has The base station unit 120 of the relay device 100 can be identified.

  Alternatively, the HNB Name specific to the base station unit 120 of the relay device 100 is determined in advance and stored in the storage unit of the base station unit 120 and the terminal unit 110, and the terminal unit 110 stores the HNB Name received from the base station in advance. By comparing with the HNB Name peculiar to the base station part of the relay apparatus, the base station that has transmitted the signal can be recognized as the base station part of the relay apparatus.

  HNB Name is an arbitrary character string of less than 48 × 8 bits of UTF-8 (8-bit UCS Transformation Format). In this embodiment, the character string of HNB Name transmitted by the base station unit 120 of the relay apparatus 100 is used by defining one or more character strings common to the relay apparatus to which the present invention is applied, for example. The HB Name may be set in advance in the storage unit 112 of the terminal unit 110 of the relay device 100 and the storage unit 123 of the base station unit 120 by the wireless communication operator or the vendor of the relay device, You may set by transmitting from an apparatus.

  Also, HNB Name is transmitted by SIB9. Therefore, the terminal unit 110 of the relay apparatus 100 cannot confirm the HNB Name before starting the handover process at the time of handover. Therefore, in the present embodiment, the base station section that has been determined to be the base station section of the relay apparatus so that the radio base station and the base station section of the relay apparatus can be identified even at the base station search stage before the start of the handover process. The PCI is automatically stored as a PCI list in the terminal unit of the relay device, and the terminal unit has identified the base station unit of the relay device in the past by checking the PCI list before starting the handover process. The base station part can be identified even before the handover process is started and the HNB Name has not yet been received. The PCI list and the HNB Name transmitted by the base station unit of the relay apparatus are stored in the storage unit 112 of the terminal unit 110 of the relay apparatus 100.

The connection procedure to the radio base station in the terminal unit including processing for the terminal unit to prevent radio connection with the base station unit of the relay apparatus will be described with reference to FIG.
The terminal unit 110 in the connection waiting state (S500) starts searching for the base station (S501), and calculates the PCI of the base station from the synchronization signal acquired from the base station (S502). The terminal unit 110 collates the calculated PCI with the PCI in the PCI list stored in the storage unit 112 of the terminal unit 110 (S503). If they do not match as a result of the collation, the base station obtains a reference signal and measures the power of the received signal (S504). If the PCI calculated in step 502 matches the PCI in the PCI list, the process returns to the start of base station search (S501). By collating with the PCI list in step 503, wireless connection with the base station unit that the terminal unit 110 previously determined as the base station unit of the relay apparatus is prevented.

  If the PCI calculated in step 502 does not match the PCI in the PCI list, the normal connection procedure of FIG. 3 is performed until reference signal acquisition, signal strength measurement, base station adequacy confirmation (S504), and information block acquisition (S505). Follow the same procedure. When acquiring an information block, first, the transmission schedule of SIBs subsequent to SIB2 notified by SIB1 is confirmed, and whether or not SIB9 transmitting HNB Name is scheduled to be received from the base station is confirmed (S506). When there is no plan to receive SIB9 from the base station, other system information received from the SIB is confirmed, and a connection candidate base station is selected (S510).

  When there is a plan to receive SIB9 from the base station, HNB Name is acquired (S507), and the acquired HNB Name is collated with HNB Name stored in advance in storage unit 112 of terminal unit 110 (S508). If the acquired HNB Name does not match the HNB Name stored in the storage unit 112 of the terminal unit 110, the process proceeds to Step 510.

When the HNB Name acquired from the radio base station in Step 507 matches the HNB Name stored in the storage unit 112, the PCI calculated in Step 502 is stored in the PCI list (S509), and then the base station search is started (S501). Return to. By performing the processing of step 508, it is possible to prevent the terminal unit from connecting to the base station unit of the relay device that has not been determined as the base station unit of the relay device until now.
The above process is repeated until an appropriate connection candidate is found. When a connection candidate is found, connection processing is performed with the radio base station (S511), and the state transitions to the connection state (S512).

Next, the procedure up to the start of the handover process of the terminal unit according to the embodiment of the present invention will be described with reference to FIG.
First, the terminal unit 110 in the connected state (S600) starts a base station search (S601). The terminal unit performs the same procedure as the handover procedure described with reference to FIG. 4 from the base station to the synchronization signal acquisition and the PCI calculation (S602). The terminal unit of the relay device collates the PCI calculated in step 602 with the PCI list stored in the storage unit of the terminal unit (S603), and if they do not match, obtains the reference signal and measures the power of the received signal ( S604). Thereafter, the handover procedure is performed in the same manner as the handover procedure described with reference to FIG.
If the calculated PCI matches the PCI in the PCI list, the process returns to the base station search start (S601). Thereby, when the terminal unit connects to the radio base station, it is possible to prevent handover to a base station unit having a PCI determined in the past as being a base station unit of the own relay device or a base station unit of another relay device.

  Next, the procedure after the start of the handover process in the present embodiment will be described with reference to FIG. After the handover process starts (S700), the terminal unit of the relay apparatus acquires the information block of the handover destination base station (S701), and confirms the reception schedule of SIB9 notified by SIB1 of the information block (S702). If there is no plan to receive SIB9 from the handover destination base station, a handover completion notification is sent to the handover destination base station (S708). When the reception schedule of SIB9 is confirmed in step 702, the terminal unit of the relay apparatus acquires HNB Name from SIB9 of the information block transmitted by the handover destination base station (S703), and stores the acquired HNB Name and the terminal unit. The HNB Name stored in the section is collated (S704). If the received HNB Name does not match the HNB Name stored in the storage unit 112, the handover process of the handover destination base station and the handover source base station is performed, and when the handover is completed, a handover process completion notification is transmitted (S708). Is completed (S709).

  If the HNB Name acquired from the handover destination base station in step 703 matches the HNB Name stored in the storage unit, the PCI of the handover destination base station is stored in the PCI list of the storage unit of the terminal unit (S705). . Thereafter, a reconnection request is transmitted to the handover source base station without notifying the handover destination base station of the completion of the handover process (S706). If it is possible to connect to the handover source base station, the connection state is maintained, and if the connection is impossible, the connection wait state is entered (S707).

In the present invention described above, the terminal unit is handed over to the base station unit 120 that has not been determined to be the base station unit 120 of the own relay device 100 or the base station unit 120 of the other relay device 100 before connecting to the radio base station. It is prevented.
From the above, the processing for preventing the terminal unit 110 of the relay device 100 from connecting to the base station unit 120 of the own relay device 100 or the base station unit 120 of the other relay device 100 in the present embodiment has been described.

Next, a PCI list stored in the storage unit 112 of the terminal unit 110 of the relay apparatus 100 will be described with reference to FIG.
FIG. 8 is a diagram illustrating a configuration example of a PCI list.
In the present embodiment, a maximum of 32 PCIs can be stored in the PCI list. As described with reference to FIG. 5, the PCI list stores the calculated PCI when the HNB Name acquired by the terminal unit from the radio base station matches the HNB Name stored in the storage unit of the terminal unit. When a terminal unit connects to a radio base station according to a PCI list, the terminal unit connects or performs handover to a base station unit having a PCI that has been determined to be a base station unit of its own relay device or a base station unit of another relay device in the past. Can be prevented.

  In the radio communication system using LTE as the radio communication system, the terminal unit can have a value of 0 to 503 for the PCI of the radio base station. Therefore, a 9-bit area is required to store one PCI, and a 5-bit area is required to store the indexes from 0 to 31 in the list.

  In the embodiment described above, the relay device is described as an example of a configuration in which the terminal unit and the base station unit are integrated, but the terminal unit and the base station unit are separate casings, and when the relay device is installed, The relay unit may be assembled by transporting the terminal unit and the base station unit to the installation location and connecting the interface unit with a LAN cable or an optical cable having an arbitrary length.

DESCRIPTION OF SYMBOLS 100 Relay apparatus 110 Terminal part 111 Terminal part wireless processing part 112 Terminal part storage part 113 Terminal part interface part 120 Base station part 121 Base station part wireless processing part 122 Base station part interface part 123 Base station part storage part 200,400 Wireless base station 300 Wireless terminal

Claims (9)

A relay device that relays wireless communication between a base station and a wireless terminal,
The base station unit includes a terminal unit that performs radio communication with the base station and a base station unit that performs radio communication with the radio terminal. The base station unit transmits a broadcast signal including base station information allocated to the base station unit of the relay apparatus. A relay device characterized by:   The relay apparatus according to claim 1, wherein each of the base station unit and the terminal unit includes a storage unit, and base station information assigned to the base station unit of the relay device includes a storage unit of the base station unit and A relay device characterized in that it is stored in advance in a storage unit of the terminal unit or received via a communication line and stored in advance. The relay device according to claim 2,
The base station unit transmits base station information assigned to the base station unit of the relay device in a system information block that transmits base station information of a broadcast signal,
The terminal unit transmits a system information block that transmits the base station information to schedule information of a head block of the system information block of the broadcast signal for the base station unit and the base station from which the terminal unit can receive signals. When there is a plan, the base station information is received and collated with the base station information assigned to the base station section of the relay device stored in advance. A relay apparatus, wherein a base station that has transmitted is excluded from connection destination candidates.   4. The relay device according to claim 3, wherein when the received base station information matches the base station information assigned to the base station portion of the relay device stored in advance, A relay apparatus characterized in that an identifier of a base station that has transmitted base station information is stored in a list in the storage unit.   5. The relay device according to claim 1, wherein the base station unit and the terminal unit each have an interface unit, and operate as a relay device by connecting each interface unit with a communication cable. A relay device characterized by that. A communication method in a relay device that relays wireless communication between a base station and a wireless terminal,
A base station unit that performs radio communication with a radio terminal transmits a notification signal to be transmitted to the radio terminal including base station information previously assigned to the base station unit of the relay apparatus. The communication method according to claim 6, comprising:
The base station unit and a terminal unit that performs wireless communication with the base station receive the base station information assigned to the base station unit of the relay device in advance or via a communication line and store the base station information in advance. Communication method. The communication method according to claim 7, wherein
The base station unit is a system information block that transmits base station information of a broadcast signal, and transmits base station information that is assigned in advance to the base station unit of the relay device,
The terminal unit transmits a system information block that transmits the base station information to schedule information of a head block of the system information block of the broadcast signal for the base station unit and the base station from which the terminal unit can receive signals. When there is a plan, the base station information is received and collated with the base station information assigned to the base station section of the relay device stored in advance. A communication method, wherein a base station that has transmitted is excluded from connection destination candidates.   9. The communication method according to claim 8, wherein the terminal unit matches the received base station information with the base station information assigned to the base station unit of the relay device stored in advance. An identifier of a base station that has transmitted base station information is stored in the list of the storage unit.

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