JP6082592B2 - C-RAN system, RRH device, communication control method, and computer program - Google Patents

Description

The present invention, C-RAN (Cloud-Radio Access Netwok) system, RRH apparatus, communication control method, and a computer program.

  In recent years, what is called C-RAN has been studied as a configuration of a base station of a mobile communication system (cellular system) (see, for example, Non-Patent Document 1). In C-RAN, the base station function is physically separated into RRH (Remote Radio Head) having a radio transmission / reception function and BBU (Base Band Unit) having a baseband processing function, and a plurality of BBUs are arranged at one place. The combined BBUP (BBU Pool) and a plurality of RRHs are connected by an optical fiber cable. The BBUP has a baseband processing capability corresponding to a plurality of BBUs, and the baseband processing capability can be adaptively assigned to each RRH according to the traffic situation of each RRH.

Namba, S. et. La., "Colony-RAN Architecture for Future Cellular Network," Future Network & Mobile Summit, 2012

  However, in the above-described conventional C-RAN, since a plurality of RRHs are connected to one BBUP, if one BBUP cannot be operated due to a disaster or an accident, the influence of the plurality of RRHs is increased. There is a problem in terms of stable supply.

The present invention has been made in view of such circumstances, C-RAN system capable of improving the stable supply of communication services in C-RAN, RRH apparatus, communication control method, and computer program It is an issue to provide.

In order to solve the above problems, a C-RAN system according to the present invention includes a plurality of RRH devices and a plurality of BBUP devices capable of accommodating a plurality of RRH devices, and the plurality of RRH devices and the plurality of the plurality of RRH devices. A BBUP device is communicably connected , and each of the plurality of RRH devices confirms the presence or absence of a reply signal from the BBUP device in response to a reply request transmitted to the BBUP device to which the RRH device is connected. When the disconnection is detected, and the RRH device from which the disconnection is detected among the plurality of RRH devices is provided in order to form a communication area in which the RRH device is continuous in a plane. A connection request is transmitted to a BBUP device other than the BBUP device .

An RRH device according to the present invention includes a plurality of RRH devices and a plurality of BBUP devices capable of accommodating a plurality of RRH devices, and the plurality of RRH devices and the plurality of BBUP devices are communicably connected to each other. In the C-RAN system, in response to a reply request transmitted to the BBUP device to which the RRH device is connected, the disconnection is detected by checking the presence or absence of a reply signal from the BBUP device. And a control unit that determines whether or not to transmit a connection request to another BBUP device when a disconnection with the BBUP device to which the RRH device is connected is detected, and the control unit includes the RRH device. Is provided in order to form a communication area that is continuously continuous, a connection request is transmitted to another BBUP device .

  The RRH device according to the present invention includes a storage unit that stores information of a connection request destination of the own RRH device, and the control unit is configured to send a connection request to the other BBUP device based on the information of the connection request destination. The transmission is performed.

  In the RRH apparatus according to the present invention, the RRH apparatus includes a storage unit that stores information on a frequency band of the own RRH apparatus, and the control unit has a frequency band of a predetermined frequency band based on the information on the frequency band. In this case, a connection request to the other BBUP device is transmitted.

  The RRH apparatus according to the present invention includes a storage unit that stores information on transmission power of the own RRH apparatus, and the control unit determines that the transmission power of the own RRH apparatus is based on the transmission power information. In the case described above, a connection request is transmitted to the other BBUP device.

  The RRH apparatus according to the present invention includes a storage unit that stores information on the throughput of the own RRH apparatus, and the control unit has a throughput before the disconnection that is greater than or equal to a predetermined throughput based on the throughput information. In some cases, a connection request to the other BBUP device is transmitted.

  The RRH device according to the present invention includes a storage unit that stores information on a resource usage rate of the own RRH device, and the control unit uses the resource usage rate before the disconnection based on the resource usage rate information. Is equal to or higher than a predetermined resource usage rate, a connection request is transmitted to the other BBUP device.

  In the RRH apparatus according to the present invention, the RRH apparatus includes a storage unit that stores information on the number of user terminals existing in the communication area of the own RRH apparatus, and the control unit performs the connection based on the information on the number of user terminals. When the number of user terminals before the disconnection is equal to or greater than a predetermined number of user terminals, a connection request is transmitted to the other BBUP device.

A communication control method according to the present invention includes a plurality of RRH devices and a plurality of BBUP devices capable of accommodating a plurality of RRH devices, and the plurality of RRH devices and the plurality of BBUP devices are connected to be communicable. In the C-RAN system, the RRH device confirms the presence or absence of a reply signal from the BBUP device in response to a reply request transmitted to the BBUP device connected to the RRH device. by detecting the disconnection, the RRH device executes a step of determining whether to transmit a connection request to another BBUP device when detecting a disconnection between the BBUP device, wherein In the determining step, when the RRH device is provided to form a planar continuous communication area, a connection request is transmitted to another BBUP device. Characterized in that it.

A computer program according to the present invention includes a plurality of RRH devices and a plurality of BBUP devices capable of accommodating a plurality of RRH devices, and the plurality of RRH devices and the plurality of BBUP devices are connected to be communicable. In the C-RAN system, a computer program for performing communication control processing of the RRH device, and in response to a reply request transmitted to the BBUP device connected to the RRH device, the presence or absence of a reply signal from the BBUP device by checking, detecting the disconnection, to execute the steps of determining whether to transmit a connection request to another BBUP device to the computer when detecting disconnection of the BBUP device, wherein In the determining step, the RRH device is provided to form a continuous communication area. When, characterized in that it is a computer program order to send a connection request to another BBUP device.

  According to the present invention, it is possible to improve the stable supply of communication services in C-RAN. For example, when a failure occurs in a certain BBUP, the RRH connected to the BBUP can be connected to another BBUP, so all RRH communication services connected to the BBUP are stopped due to the failure of a certain BBUP. Thus, it is possible to prevent communication from being interrupted in a large area.

1 is a schematic configuration diagram of a C-RAN system according to an embodiment of the present invention. It is a block diagram which shows the structural example of RRH1 which concerns on one Embodiment of this invention. It is a block diagram which shows the structural example of BBUP2 which concerns on one Embodiment of this invention. It is a flowchart which shows the process sequence of RRH1 which concerns on Example 1 of this invention. It is a flowchart which shows the process sequence of BBUP2 which concerns on Example 5 of this invention. It is a flowchart which shows the process sequence of BBUP2 which concerns on Example 6 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a C-RAN system according to an embodiment of the present invention. 1, a plurality (six in the example of FIG. 1) of RRH devices (hereinafter simply referred to as RRH) 1 and a plurality of (two in the example of FIG. 1) BBUP devices (hereinafter simply referred to as BBUP) 2. Are connected to the ring-type communication network 100. Each RRH 1 and each BBUP 2 can communicate with each other via the communication network 100. Note that the network topology of the communication network 100 only needs to allow one RRH 1 to be communicably connected to a plurality of BBUPs 2. For example, a ring type, a mesh type, a bus type, a star type combination, or the like can be used, and is not particularly limited. .

  FIG. 2 is a block diagram illustrating a configuration example of the RRH 1 according to the present embodiment. In FIG. 2, the RRH 1 includes a radio unit 11, a BBUP communication unit 12, a control unit 13, and a storage unit 14. The wireless unit 11 transmits and receives wireless signals to and from the wireless terminal. The inter-BBUP communication unit 12 communicates with the BBUP 2 via the communication network 100. The control unit 13 controls the own RRH1. The storage unit 14 stores data.

  FIG. 3 is a block diagram illustrating a configuration example of the BBUP 2 according to the present embodiment. In FIG. 3, BBUP 2 includes a BBUP processing unit 21, an RRH communication unit 22, a control unit 23, and a storage unit 24. The BBUP processing unit 21 has a baseband processing function, and the baseband processing capability corresponds to a plurality of BBUs. The inter-RRH communication unit 22 communicates with the RRH 1 via the communication network 100. The control unit 23 controls the own BBUP2. The storage unit 24 stores data.

  Hereinafter, the operation of the C-RAN system according to the present embodiment will be described with examples.

  FIG. 4 is a flowchart showing the processing procedure of the RRH 1 according to the first embodiment of the present invention. First, in FIG. 1, each RRH 1 is connected to one of the BBUPs 2. For example, it is assumed that RRH1_ # 1 to 3 are connected to BBUP2_ # 1, and RRH1_ # 4 to 6 are connected to BBUP2_ # 2.

  Here, it is assumed that any BBUP2 is suspended for some reason. For example, suppose that BBUP2_ # 1 is suspended. Thereby, each RRH1_ # 1-3 connected to BBUP2_ # 1 detects disconnection with BBUP2_ # 1. As a method for detecting this disconnection, for example, it is possible to periodically check the existence between each RRH1_ # 1 to 3 and BBUP2_ # 1. As the existence confirmation method, for example, there is a method in which a reply request is made from one apparatus that performs existence confirmation to the counterpart apparatus, and the presence or absence of a reply signal (ACK signal) from the counterpart apparatus is confirmed.

  In each RRH1_ # 1 to 3, when the control unit 13 detects disconnection with the BBUP2_ # 1, the control unit 13 starts the process of FIG. Hereinafter, the communication control method according to the first embodiment will be described with reference to FIG.

(Step 11) The control unit 13 confirms whether the own RRH1 is used for area coverage. The storage unit 14 stores in advance information indicating whether or not the own RRH 1 is for area coverage. The control unit 13 refers to the information in the storage unit 14 to confirm whether the own RRH 1 is for area coverage. As a result, if the local RRH1 is for area cover, the process proceeds to step S12. If it is not for area cover, the process of FIG.

  The area covering RRH 1 is an RRH 1 provided to form a planar continuous communication area. Accordingly, the area covering RRH 1 is more important than the RRH 1 provided to form a local communication area.

(Step S12) The control unit 13 transmits a connection request to the BBUP2_ # 2 by the inter-BBUP communication unit 12. The storage unit 14 stores in advance information (communication address, etc.) of the BBUP2_ # 2 that is a partner to which a connection request is transmitted when the disconnection with the BBUP2_ # 1 is detected. The control unit 13 refers to the information in the storage unit 14 to obtain information on the BBUP2_ # 2 that is a partner to which the connection request is transmitted.

(Step S13) The control unit 13 determines whether or not the connection request is permitted from BBUP2_ # 2 that is the partner that transmitted the connection request. As this determination method, for example, when a connection request permission notification is received from BBUP2_ # 2 within a predetermined period from the time when the connection request is transmitted, it is determined that the connection request is permitted, and the connection request is permitted from BBUP2_ # 2. If the notification is not received, it is determined that the connection request is not permitted. As a result, if it is determined that the connection request is permitted, the process proceeds to step S14. If it is determined that the connection request is not permitted, the process returns to step S12.

(Step S14) The control unit 13 establishes communication connection to BBUP2_ # 2 by the inter-BBUP communication unit 12. Thereby, the RRH 1 can continue the communication service by BBUP2_ # 2.

  In the above-described embodiment, whether or not to send a connection request to another BBUP 2 is determined based on information indicating whether or not RRH 1 is for area coverage. However, the determination is performed using other information. You may go. Examples of using other information are given below.

  For example, information on the connection request destination of the RRH 1 (for example, the communication address of the emergency connection destination BBUP 2 when the connection with the BBUP 2 is disconnected) is stored, and the determination is made based on the information on the connection request destination. Alternatively, information on whether or not there is a connection request for RRH1 is stored, and a connection request is transmitted to another BBUP 2 based on the information on whether or not there is a connection request. The connection request presence / absence information indicates whether the RRH 1 makes a connection request (with a connection request) or does not make a connection request (no connection request). Alternatively, priority information indicating whether or not RRH1 is prioritized is stored, and a connection request to another BBUP2 is transmitted based on the priority information.

  Alternatively, information on the frequency band of RRH1 may be stored, and if the frequency band is a predetermined frequency band based on the information on the frequency band, a connection request may be transmitted to another BBUP2. For example, when the communication area is a low frequency band (for example, 800 MHz band), a connection request for another BBUP 2 is transmitted.

  Alternatively, RRH1 transmission power information may be stored, and if the transmission power is equal to or higher than a predetermined transmission power based on the transmission power information, a connection request may be transmitted to another BBUP2. For example, when the transmission power reaches a predetermined size or more, a connection request is transmitted to another BBUP 2.

  Alternatively, the RRH1 throughput information is stored, and if the throughput before the disconnection with the BBUP2 is equal to or higher than the predetermined throughput based on the throughput information, a connection request to another BBUP2 is transmitted.

  Alternatively, information on the resource usage rate of RRH1 is stored, and when the resource usage rate before disconnection from BBUP2 is equal to or higher than a predetermined resource usage rate based on the resource usage rate information, another BBUP2 Send connection request to.

  Alternatively, information on the number of user terminals existing in the communication area of RRH1 is stored, and based on the information on the number of user terminals, the number of user terminals before disconnecting from BBUP2 is equal to or greater than the predetermined number of user terminals. In this case, a connection request to another BBUP 2 is transmitted.

  Alternatively, information on the signal power of the downlink or uplink between the RRH 1 and the user terminal is stored, and based on the signal power information, the signal power before disconnection from the BBUP 2 is equal to or higher than a predetermined signal power Transmits a connection request to another BBUP2.

  Alternatively, PAPR (Peak to Average Power Ratio) information of a downlink signal between the RRH 1 and the user terminal is stored, and based on the PAPR information, the PAPR before disconnection from the BBUP 2 is equal to or higher than a predetermined PAPR. In some cases, a connection request to another BBUP 2 is transmitted.

  The second embodiment is a modification of the first embodiment. In the second embodiment, information indicating whether the RRH 1 is in a communication area of another wireless communication system other than the own C-RAN system is stored in the storage unit 14. And when RRH1 detects the disconnection with BBUP2_ # 1, when it exists in the communication area of another radio | wireless communications system, the said RRH1 does not perform a connection request | requirement to BBUP2_ # 2.

  Note that information indicating no connection request is set for the RRH 1 in the communication area of another wireless communication system other than the own C-RAN system, and the RRH 1 determines other BBUP 2 based on the information indicating no connection request. The connection request may not be transmitted.

  The third embodiment is a modification of the second embodiment. In the third embodiment, when the RRH1 detects a disconnection with the BBUP2_ # 1, when the RRH1 is not for area coverage and is in a communication area of another wireless communication system, the RRH1 is BBUP2_ #. 2 is temporarily requested for connection. In this case, when RRH1 makes a temporary connection request, RBUP2_ # 2 receives identification information (for example, the name and identification number of the wireless communication system) of another wireless communication system supporting the same communication area. Etc.)

  When BBUP2_ # 2 receives a temporary connection request from RRH1, BBUP2_ # 2 accommodates RRH1 for a predetermined period. BBUP2_ # 2 can use information indicating that a communication failure has occurred for the user terminal in the communication area and the available wireless communication system via the accommodated RRH1 during the accommodation period. Information indicating the wireless communication system is notified. As a notification method, a broadcast channel by the radio unit 11 of the RRH 1 can be used. Thereby, it is possible to prompt the user of the user terminal to use another wireless communication system.

  Further, RRH1 stores the broadcast signal received from BBUP2_ # 2, and repeatedly transmits the stored broadcast signal, so that the user terminal user can be used even after the accommodation period in BBUP2_ # 2 has expired. However, it is possible to encourage the use of another wireless communication system.

  Note that information regarding whether or not there is a temporary connection request may be set for the RRH 1, and a temporary connection request may be made to another BBUP 2 based on the information about whether or not the temporary connection request is present.

  The fourth embodiment is a modification of the first to third embodiments. In Example 4, when RRH1_ # 1-3 connected to BBUP2_ # 1 detect disconnection with BBUP2_ # 1, each RRH1_ # 1-3 sends a connection request to BBUP2_ # 2 with a time difference. Send. As a method of giving this time difference, for example, the number of user terminals existing in the communication area of RRH1 can be used. An example of this will be described. First, the number of user terminals immediately before the connection with BBUP2_ # 1 is disconnected or the average value of the number of users in the predetermined time range immediately before the connection with BBUP2_ # 1 is calculated is calculated. Next, when the calculated value is larger than the upper limit value of the number of user terminals that can be accommodated in the RRH1, the waiting time until the connection request is transmitted is shorter than the specified value, whereas when the calculated value is small, the connection request is transmitted. The waiting time until is longer than the specified value.

  Further, when the own RRH 1 is in a communication area of another wireless communication system, the waiting time until connection request transmission may be increased. For example, a fixed offset value may be added, or the waiting time may be increased by multiplying a specific coefficient.

  Further, instead of the number of user terminals, the throughput in the sector or cell may be a factor for determining the waiting time until connection request transmission.

  Note that as one method for obtaining the number of user terminals or throughput in RRH1, there is a method of periodically notifying the number of user terminals or throughput from BBUP2 to RRH1. On the other hand, as a method for obtaining the number of user terminals or throughput in RRH1 without using information from BBUP2, for example, the magnitude of the downlink or uplink signal power between RRH1 and the user terminal is determined, and the signal power is large. If it is determined that the waiting time is shorter than the specified value, and if it is determined that the signal power is small, the waiting time is set longer than the specified value.

  Further, the waiting time until connection request transmission may be controlled by using the PAPR of the downlink signal between the RRH 1 and the user terminal. Note that CFR (Crest Factor Reduction) and DPD (Digital Pre-Distortion) are often used in power amplifiers for downlink signals for the purpose of power saving and linearity improvement. A value is measured and the number of times this measured value exceeds a certain threshold (eg, 70% of the maximum value of the digital signal) is counted. And if the count number is greater than the specified value, it can be estimated that the throughput is high, so the waiting time is shorter than the specified value, whereas if the count number is less than the specified value, it can be estimated that the throughput is low. Set the waiting time longer than the specified value.

  FIG. 5 is a flowchart showing a processing procedure of BBUP 2 according to the fifth embodiment of the present invention. The fifth embodiment is an embodiment of BBUP2 that has received a connection request from the RRH1. In BBUP2, upon receiving a connection request from RRH1, control unit 23 starts the process of FIG. The communication control method according to the fifth embodiment will be described below with reference to FIG.

(Step 21) The control unit 23 determines whether the resources of the own BBUP2 have room. As this determination method, for example, the control unit 23 monitors the resource usage amount of its own BBUP 2 and determines that there is a margin in the resource when the resource usage amount is less than a predetermined amount. Specifically, for example, the load applied to the signal processing circuit of the own BBUP 2 is monitored, and if the load is less than a predetermined amount, it is determined that there is a margin in resources. As a result, when it is determined that there is a margin in resources, the process proceeds to step S22, and when it is determined that there is no margin in the resources, the process proceeds to step S23.

(Step S22) The control unit 23 uses the inter-RRH communication unit 22 to send a connection permission response to the RRH 1 that has transmitted the connection request.

(Step S23) The control unit 23 responds to the RRH 1 that has transmitted the connection request to the RRH 1 that has transmitted the connection request by the inter-RRH communication unit 22.

  The sixth embodiment is a modification of the fifth embodiment. FIG. 6 is a flowchart showing the processing procedure of BBUP2 according to the sixth embodiment of the present invention. In BBUP2, when receiving a connection request from RRH1, the control unit 23 starts the process of FIG. Hereinafter, the communication control method according to the sixth embodiment will be described with reference to FIG.

(Step 31) The control unit 23 determines whether the resources of the own BBUP2 have room. As a result, when it is determined that there is a margin in resources, the process proceeds to step S32, and when it is determined that there is no margin in the resources, the process proceeds to step S33.

(Step 32) The inter-RRH communication unit 22 sends a connection permission response to the RRH 1 that has transmitted the connection request.

(Step S <b> 33) The control unit 23 confirms whether or not the own BBUP 2 is connected to the RRH 1 that is not for area coverage. The storage unit 24 stores in advance information indicating whether each RRH 1 is for area coverage. Further, the storage unit 24 appropriately updates and stores information indicating the RRH 1 that is being connected to the own BBUP 2 in accordance with a change in the connection with the own BBUP 2. The control unit 23 refers to the information in the storage unit 24 to confirm whether or not the own BBUP 2 is connected to the RRH 1 that is not for area coverage. As a result, when the own BBUP2 is connected to the RRH1 that is not for area coverage, the process proceeds to step S34, and when it is not connected to the RRH1 that is not for area cover, the process proceeds to step S35.

(Step S <b> 34) The control unit 23 disconnects the RBB 1 that is not for the area cover that is currently connected to the BBUP 2. Thereafter, the process proceeds to step S32.

(Step S35) The control unit 23 responds to the RRH 1 that has transmitted the connection request to the RRH 1 that has transmitted the connection request by the inter-RRH communication unit 22.

  The seventh embodiment is a modification of the fifth or sixth embodiment. When the BBUP 2 determines that there is no room for its own resource, the BBUP 2 secures a resource to be allocated to the newly connected RRH 1 by limiting the resource of the signal processing circuit used in each RRH 1 connected to the BBUP 2. For example, in LTE (Long Term Evolution) system that is being standardized by 3GPP (3rd Generation Partnership Project), MIMO (Multi-Input Multi-Output) communication is stopped, or the frequency bandwidth to be used is narrowed, Alternatively, by assigning restrictions in the time direction and the frequency direction in RB (Resource Block) assignment, it is possible to secure resources to be assigned to the newly connected RRH1.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

  For example, in BBUP2, when the communication speed of the optical line or the digital interface reaches the limit instead of the resource of the signal processing circuit, the same transmission band may be shared by two or more RRHs. Thereby, the same signal can be sent as a downlink signal to a plurality of RRHs 1. For upstream signals, an adder may be installed before BBUP2. In this case, the frame synchronization of the upstream signal from the RRH 1 to which the same downstream signal is transmitted is taken, and the I and Q signals of the same time are added. On the other hand, when an adder cannot be installed in the previous stage of BBUP2, the processing load can be reduced by adding the I and Q signals after they are extracted in BBUP2.

Further, a program for realizing the above-described C-RAN system may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by the computer system and executed. Here, the “computer system” may include an OS and hardware such as peripheral devices.
“Computer-readable recording medium” refers to a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a DVD (Digital Versatile Disk), and a built-in computer system. A storage device such as a hard disk.

Further, the “computer-readable recording medium” means a volatile memory (for example, DRAM (Dynamic DRAM) in a computer system that becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Random Access Memory)), etc., which hold programs for a certain period of time.
The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

DESCRIPTION OF SYMBOLS 1 ... RRH apparatus, 2 ... BBUP apparatus, 11 ... Radio | wireless part, 12 ... BBUP communication part, 13, 23 ... Control part, 14, 24 ... Memory | storage part, 21 ... BBUP process part, 22 ... RRH communication part, 100 ... communication network

Claims (10)

A plurality of RRH devices and a plurality of BBUP devices capable of accommodating a plurality of RRH devices, wherein the plurality of RRH devices and the plurality of BBUP devices are communicably connected ,
Each of the plurality of RRH devices detects disconnection by confirming the presence or absence of a reply signal from the BBUP device in response to a reply request transmitted to the BBUP device to which the RRH device is connected,
Among the plurality of RRH devices, an RRH device that detects a disconnection is a BBUP device other than the BBUP device when the RRH device is provided to form a planar continuous communication area. A C-RAN system that transmits a connection request to a device . The RRH in a C-RAN system comprising a plurality of RRH devices and a plurality of BBUP devices capable of accommodating a plurality of RRH devices, wherein the plurality of RRH devices and the plurality of BBUP devices are communicably connected. Device,
In response to a reply request transmitted to the BBUP device to which the RRH device is connected, by detecting the presence or absence of a reply signal from the BBUP device, the disconnection is detected,
A controller that determines whether or not to transmit a connection request to another BBUP device when a disconnection with the BBUP device to which the RRH device is connected is detected ;
The RRH device, wherein the control unit transmits a connection request to another BBUP device when the RRH device is provided to form a planar continuous communication area . A storage unit for storing information of a connection request destination of the own RRH device;
The control unit transmits a connection request to the other BBUP device based on the information of the connection request destination.
The RRH apparatus according to claim 2, wherein: A storage unit for storing information of the frequency band of the own RRH device;
When the frequency band of the own RRH device is a predetermined frequency band based on the information on the frequency band, the control unit transmits a connection request to the other BBUP device.
The RRH apparatus according to claim 2, wherein: A storage unit that stores information on transmission power of the own RRH device;
The control unit transmits a connection request to the other BBUP device when the transmission power of the own RRH device is equal to or higher than a predetermined transmission power based on the transmission power information.
The RRH apparatus according to claim 2, wherein: A storage unit for storing information on the throughput of the own RRH device;
The control unit, based on the throughput information, transmits a connection request to the other BBUP device when the throughput before the disconnection is equal to or higher than a predetermined throughput.
The RRH apparatus according to claim 2, wherein: A storage unit for storing information on the resource usage rate of the own RRH device;
The control unit transmits a connection request to the other BBUP device when the resource usage rate before the disconnection is equal to or higher than a predetermined resource usage rate based on the resource usage rate information.
The RRH apparatus according to claim 2, wherein: A storage unit for storing information on the number of user terminals located in the communication area of the own RRH device;
The control unit, based on the information on the number of user terminals, transmits a connection request to the other BBUP device when the number of user terminals before the disconnection is equal to or greater than a predetermined number of user terminals.
The RRH apparatus according to claim 2, wherein: Communication control in a C-RAN system comprising a plurality of RRH devices and a plurality of BBUP devices capable of accommodating a plurality of RRH devices, wherein the plurality of RRH devices and the plurality of BBUP devices are communicably connected. Is the way
In response to a reply request transmitted from the RRH device to the BBUP device connected to the RRH device, by detecting the presence or absence of a reply signal from the BBUP device, detecting a disconnection;
The RRH device, and determining whether to transmit a connection request to another BBUP device when detecting a disconnection between the BBUP device
Run
In the determining step, when the RRH device is provided to form a continuous communication area, a communication control method is characterized in that a connection request is transmitted to another BBUP device . The RRH in a C-RAN system comprising a plurality of RRH devices and a plurality of BBUP devices capable of accommodating a plurality of RRH devices, wherein the plurality of RRH devices and the plurality of BBUP devices are communicably connected. A computer program for performing communication control processing of a device,
Detecting a disconnection by confirming the presence or absence of a reply signal from the BBUP device in response to a reply request transmitted to the BBUP device connected to the RRH device;
And determining whether to transmit a connection request to another BBUP devices cause the computer to execute when detecting disconnection of the BBUP device,
Wherein in the determination steps, if the RRH device is provided in order to form a surface continuous communication area, because the computer program to send a connection request to another BBUP device.

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