JP6359983B2 - Station side optical line termination device and discovery processing execution method - Google Patents

Description

  The present invention relates to a station side optical line termination device and a discovery processing execution method.

  Cellular system traffic is increasing year by year. In order to cope with rapidly increasing traffic, it is essential to expand communication capacity in the future cellular systems. Therefore, it has been studied to install a base station (small cell) smaller than a conventional macro cell. By arranging a large number of small cells, the network density is increased and the communication capacity is improved. Since the number of base stations increases, efficient accommodation of optical links is necessary in the network (mobile backhaul) between the base stations and the core network.

  Moreover, the structure which divided | segmented the function of the base station into the baseband signal processing part (BBU: Base Band Unit) and the radio | wireless transmission / reception part (RRH: Remote Radio Head) for the flexible arrangement | positioning of many small cells is taken. A C-RAN (Centralized Radio Access Network) configuration in which a plurality of RRHs are accommodated in a single BBU is also proposed. This configuration facilitates centralized control and cooperative operation. Even in this BBU-RRH network (mobile fronthaul), the number of optical links increases according to the number of small cells, so that efficient accommodation of optical links is necessary.

  Therefore, it has been studied to construct a mobile fronthaul or a mobile backhaul with a PON (passive optical network) (see, for example, Patent Document 1 and Patent Document 2). The PON technology is expected to be economical because a plurality of optical fibers can be aggregated.

International Publication No. 2014/061552 Japanese Patent Application Laid-Open No. 2014-120783

  In GE-PON (IEEE 802.3ah), 10G-EPON (IEEE 802.3av), etc., when an ONU is newly connected to the PON, OLT (Optical Line Terminal: station side optical line terminator) is automatically generated by the discovery process. A link between ONUs (Optical Network Units: subscriber side optical line terminators) is established. At this time, the OLT transmits a discovery gate frame and waits to receive a register request frame from the ONU for a time called a discovery window. Therefore, the OLT cannot receive other uplink data during the discovery window.

  FIG. 12 shows the configuration of the OLT used in the PON. FIG. 12 is a block diagram showing a configuration of the OLT 50 in the conventional mobile network. As illustrated in FIG. 12, the OLT 50 includes an NW-IF 521, a PON-IF 522, a downlink communication control unit 523, an uplink communication control unit 524, and a discovery processing unit 525.

The NW-IF 521 is an interface for transmitting and receiving signals to and from a device located on the upstream side of the own device.
The PON-IF 522 is an interface for transmitting and receiving signals to and from a device located on the downstream side (for example, the PON side) of the own device.
The downlink communication control unit 523 buffers downlink data transmitted from a device located on the upstream side, converts the downlink data into a PON frame, and transmits the PON frame to the downstream side.
The uplink communication control unit 524 buffers the uplink data transmitted from the device located on the downstream side, returns the PON frame to the original frame, and transmits it to the upstream side.
The discovery processing unit 525 performs discovery processing.

  In FIG. 12, downlink data is input from the NW-IF 521, buffered by the downlink communication control unit 523, and converted into a PON frame. Then, the downlink data converted into the PON frame is output from the downlink communication control unit 523 to the downstream side via the PON-IF 522. The uplink data is input from the PON-IF 522, buffered by the uplink communication control unit 524, and returned from the PON frame to the original frame. The uplink data returned to the original frame is output from the uplink communication control unit 524 to the upstream side via the NW-IF 521.

  Here, when performing the discovery process, the discovery processing unit 525 transmits a discovery gate frame to the newly registered ONU. The discovery gate frame is output from the downlink communication control unit 523 via the PON-IF 522. When the discovery gate frame is transmitted, the OLT 50 sets a discovery window. Then, the OLT 50 executes a discovery process during the set discovery window.

  FIG. 13 is a diagram illustrating an example when a discovery window is set. The vertical axis represents the traffic volume in the light section, and the horizontal axis represents time. Since it is assumed that the wireless system performs communication using the time division duplex method, traffic in the optical section is alternately generated in the uplink and the downlink. In FIG. 13, a discovery window is set during transmission of uplink data. In this case, since the uplink communication control unit 524 is waiting for receiving the register request frame during the discovery window, it cannot receive other uplink data. When receiving the register request frame, the uplink communication control unit 524 sends the register request frame to the discovery processing unit 525. The discovery processing unit 525 assigns an LLID (Logical Link ID), a transmission band, and a transmission timing to the ONU that has transmitted the register request frame. Then, the discovery processing unit 525 sends a register frame (register flame) including the assigned LLID and a gate frame (gate flame) including the transmission band and the transmission timing from the downlink communication control unit 523 via the PON-IF 522. Send to the ONU that sent the frame.

  As described above, in the conventional OLT, while waiting for the reception of the register request frame from the ONU during the period in which the discovery window is set, other upstream data cannot be received. Therefore, there has been a problem that uplink communication efficiency is reduced.

  In view of the above-described problems, an object of the present invention is to provide a technique capable of reducing a decrease in uplink communication efficiency when transmitting data of a mobile network using a PON.

  One aspect of the present invention includes a time division duplex radio system including a plurality of radio base stations that perform communication by a time division duplex method, a PON system including a subscriber side optical line termination device and a station side optical line termination device, and An optical line terminator in a radio communication system comprising: an acquisition unit for acquiring time division duplex information indicating uplink and downlink communication timing in the time division duplex radio system; Based on the received time division duplex information, a period in which uplink data transmission is not performed in the optical communication section is determined, and a connection between the new subscriber side optical line terminator and the station side optical line terminator A station comprising: a timing determination unit that determines a timing for executing a discovery process for establishing a discovery process; and a discovery processing unit that executes a discovery process at the determined timing An optical line termination equipment.

  One aspect of the present invention is the above-mentioned station-side optical line termination device, wherein the acquisition unit acquires the time division duplex information from a downlink signal transmitted to a radio terminal. To do.

  One aspect of the present invention includes a time division duplex radio system including a plurality of radio base stations that perform communication by a time division duplex method, a PON system including a subscriber side optical line termination device and a station side optical line termination device, and A discovery processing execution method performed by a station-side optical network terminating device in a wireless communication system configured to acquire time division duplex information indicating uplink and downlink communication timings in the time division duplex wireless system And determining a period during which uplink data transmission is not performed in the optical communication section based on the acquired time division duplex information, and a new subscriber side optical line terminating device and the station side optical Timing determination step for determining the timing for executing discovery processing for establishing a connection with the line termination device, and discovery processing at the determined timing A discovery process executing a discovery process execution method having.

  ADVANTAGE OF THE INVENTION According to this invention, when transmitting the data of a mobile network by PON, it becomes possible to reduce the fall of uplink communication efficiency.

1 is a system diagram showing a system configuration of a mobile network 1 in a first embodiment of the present invention. It is explanatory drawing of a TDD frame of LTE. It is a block diagram which shows the structure of OLT11 in the 1st Embodiment of this invention. It is a block diagram which shows the structure of ONU13 in the 1st Embodiment of this invention. It is a figure which shows the operation example of a discovery process. It is explanatory drawing of the data transmission in an uplink and a downlink. It is explanatory drawing of the periodicity of the communication traffic in an uplink. It is a flowchart which shows the flow of the process which OLT11 of this invention performs. It is a system diagram which shows the system configuration | structure of the mobile network 101 in the 2nd Embodiment of this invention. It is a block diagram which shows the structure of OLT111 in the 2nd Embodiment of this invention. It is a block diagram which shows the structure of OLT211 in the 3rd Embodiment of this invention. It is a block diagram which shows the structure of OLT in the conventional mobile network. It is a figure which shows an example at the time of setting a discovery window.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
FIG. 1 is a system diagram showing a system configuration of a mobile network 1 according to the first embodiment of the present invention. In the first embodiment, a case where a PON is applied to a mobile fronthaul will be described.

  The mobile network 1 in the first embodiment includes an OLT 11, a splitter 12, ONUs 13a to 13c, a BBU 14, and RRHs 15a to 15c. In FIG. 1, one end (upstream side) of the optical fiber 10 is connected to the OLT 11. A BBU 14 is connected to the OLT 11. The other end (downstream side) of the optical fiber 10 is branched by the splitter 12 and connected to the ONUs 13a, 13b, and 13c. The ONU 13a is connected to the RRH 15a, the ONU 13b is connected to the RRH 15b, and the ONU 13c is connected to the RRH 15c. In the following description, the ONUs 13a to 13c are described as ONUs 13 unless otherwise distinguished. In the following description, RRH15a to 15c will be described as RRH15 unless otherwise distinguished.

The OLT 11 is configured using an information processing apparatus. The OLT 11 performs discovery processing when the ONU 13 is newly connected to the PON.
The splitter 12 distributes the optical signal transmitted from the OLT 11 and transmits it to the ONU 13. Further, the splitter 12 aggregates the optical signals transmitted from the ONU 13 and transmits them to the OLT 11.
The ONU 13 performs wired communication with the OLT 11 via the optical fiber 10 and the splitter 12. Further, the ONU 13 performs wireless communication with a device (for example, the RRH 15) located on the downstream side of the own device.

The BBU 14 performs base station timing control and baseband signal processing.
The RRH 15 processes the high frequency signal of the base station. The transmission signal is sent from the BBU 14 to the RRH 15 via the OLT 11, the optical fiber 10, the splitter 12, and the ONU 13. The transmission signal is converted into a desired high-frequency signal by the RRH 15, and the power is amplified and transmitted. The received signal is sent from the RRH 15 to the BBU 14 via the ONU 13, the splitter 12, the optical fiber 10, and the OLT 11. Thereafter, baseband processing is performed by the BBU 14 and the received data is demodulated.

  The radio system used in the mobile network 1 as shown in FIG. 1 uses an FDD (Frequency division duplex) method that uses different frequency bands for the uplink and downlink, and the same frequency band for the uplink and downlink. There is a TDD (Time division duplex) method for changing the time band. For example, in LTE (Long term evolution), seven types of TDD frames shown in FIG. 2 are set. In TDD, the uplink and downlink communication time ratios can be flexibly set by switching the frame configuration in accordance with uplink / downlink traffic.

FIG. 2 is an explanatory diagram of an LTE TDD frame.
As shown in FIG. 2, in the LTE TDD frame, data is transferred in subframes. In FIG. 2, “D” indicates a downlink subframe, “U” indicates an uplink subframe, and “S” indicates a special subframe. The downlink subframe is a frame for transferring data in the downlink direction from the OLT 11 side to the ONU 13 side. The uplink subframe is a frame for transferring data in the upstream direction from the ONU 13 side to the OLT 11 side. The special subframe includes a downlink pilot time slot (DwPTS), a guard period (GP), and an uplink pilot time slot (UpPTS).

FIG. 3 is a block diagram showing a configuration of the OLT 11 in the first embodiment of the present invention.
As illustrated in FIG. 3, the OLT 11 includes an NW-IF 21, a PON-IF 22, a downlink communication control unit 23, an uplink communication control unit 24, a discovery processing unit 25, a BBU side interface 26, and a timing determination unit 27. With.

The NW-IF 21 is an interface for transmitting and receiving signals to and from the BBU 14 located on the upstream side of the own device.
The PON-IF 22 is an interface for transmitting and receiving signals to and from the ONU 13 located on the downstream side (for example, the PON side) of the own device.
The downlink communication control unit 23 buffers the downlink data, converts it into a PON frame, and transmits it.

The uplink communication control unit 24 buffers the uplink data and returns the PON frame to the original frame.
The discovery processing unit 25 performs discovery processing.
The BBU side interface 26 is an interface for acquiring TDD information (time division duplex information) from the BBU 14 side. Here, the TDD information is information indicating uplink and downlink communication timings in the TDD frame. The communication timing includes a timing at which communication is started and a timing at which communication ends. The communication timing may include a timing at which communication is started and a length for which communication is performed.
The timing determination unit 27 determines the timing for performing the discovery process based on the acquired TDD information.

FIG. 4 is a block diagram showing the configuration of the ONU 13 in the first embodiment of the present invention.
As shown in FIG. 4, the ONU 13 includes a radio system side IF 31, a PON-IF 32, a downlink communication control unit 33, an uplink communication control unit 34, and a register processing unit 35.

The wireless system side IF 31 is an interface for transmitting and receiving signals to and from the RRH 15 located on the downstream side of the own apparatus.
The PON-IF 32 is an interface for transmitting and receiving signals to and from the OLT 11 located on the upstream side (for example, the PON side) of the device itself.
The downlink communication control unit 33 buffers the downlink data and returns the PON frame to the original frame.
The uplink communication control unit 34 buffers the uplink data, converts it into a PON frame, and outputs it.
The register processing unit 35 holds a register frame and a gate frame sent from the OLT 11 in the discovery process.

  In the mobile network 1 according to the first embodiment of the present invention, when the ONU 13 is newly connected to the PON, a link between the OLT 11 and the ONU 13 is automatically established by the discovery process. FIG. 5 is a diagram illustrating an operation example of the discovery process. In the description of FIG. 5, a case where the ONU 13c in FIG. 1 is newly connected to the PON will be described as an example.

When the ONU 13c is newly connected to the PON, the OLT 11 discovers the newly connected ONU 13c and transmits a discovery gate frame to the discovered ONU 13c (PRC1). Thereafter, the OLT 11 waits for a time called a discovery window until it receives a register request frame from the ONU 13c.
Upon receiving the discovery gate frame transmitted from the OLT 11, the ONU 13c transmits a register request to the OLT 11 after a random delay time (PRC2).

When the OLT 11 receives a register request from the ONU 13c, the OLT 11 assigns an LLID, a transmission band, and a transmission timing to the ONU 13c. Then, the OLT 11 notifies the ONU 13c of a register frame including information on the assigned LLID (PRC3). Further, the OLT 11 notifies the ONU 13c of a gate frame including information on the allocated transmission band and transmission timing (PRC4).
The ONU 13c transmits a register confirmation frame (register ack flame) to the OLT 11 using the allocated transmission band (PRC5).
The above is the operation procedure of the discovery process.

  As described above, in the mobile network 1 according to the first embodiment of the present invention, the discovery process is performed when the ONU 13c is newly connected to the PON. Thereby, a link of a new ONU 13c can be established.

  However, when the discovery process is performed, during the discovery window, the OLT 11 waits to receive a register request from the newly connected ONU 13c. Therefore, during the discovery window, the OLT 11 cannot receive other uplink data (for example, uplink data transmitted from another ONU 13). As a result, the uplink communication efficiency in the PON section is degraded.

  Therefore, in the present embodiment, as shown in FIG. 3, the OLT 11 is provided with a BBU side interface 26 and a timing determination unit 27. The BBU side interface 26 acquires TDD information from the BBU 14. Based on the TDD information, the timing determination unit 27 determines a timing for executing the discovery process in a period in which uplink data transmission is not performed. As a result, a discovery window is set in a period when there is no uplink data, and deterioration of uplink communication efficiency in the PON section can be prevented. This will be described below.

  In the TDD radio system, data is alternately transmitted on the uplink and the downlink in a time division manner. Therefore, when the front hall is accommodated in the PON, data is alternately transmitted on the uplink and the downlink even in the optical section. From this, in the optical section, there is a section in which data transmission is hardly performed in the uplink only, the downlink only, or both the uplink and the downlink.

FIG. 6 is an explanatory diagram of data transmission in the uplink and the downlink in the TDD frame.
In the case of the LTE TDD frame as shown in FIG. 2, in period Ta in FIG. 6, only downlink data transmission occurs and uplink data transmission does not occur. This period Ta is a period of DwPTS in the downlink subframe indicated by “D” and the special subframe indicated by “S” in the TDD frame shown in FIG. Further, in period Tb in FIG. 6, there occurs a period in which only uplink data transmission is performed and downlink data transmission is not performed. This period Tb is an UpPTS period of the uplink subframe indicated by “U” and the special subframe indicated by “S” in the TDD frame shown in FIG. In FIG. 6, in the period Tc, a period in which data transmission is not performed on both the uplink and the downlink occurs. This period Tc is a period of GP in the special subframe indicated by “S” in the TDD frame shown in FIG.

  As described above, during the discovery window, the OLT 11 waits to receive a register request from the ONU, and therefore cannot perform other uplink transmissions. However, uplink data transmission is not performed in the period Ta in FIG. As shown in FIG. 7, if a discovery window is set in a period Ta during which uplink data transmission is not performed, uplink data communication is not affected. In this case, if the discovery window falls within the total time of the downlink subframe of the TDD frame and DwPTS and GP, the discovery process can be performed without affecting the uplink data transmission.

  In the OLT 11 in this embodiment shown in FIG. 3, TDD information is acquired from the BBU 14 by the BBU side interface 26. For example, in the case of the TDD frame shown in FIG. 2, information on which TDD frame of a plurality of TDD frames is used can be used as TDD information. In other words, if it is possible to obtain which structure of the TDD frame is used, the length (period) of the TDD frame and the subframe timing in each frame can be known from the frame structure shown in FIG. If the OLT 11 is time-synchronized with the wireless system, it is possible to specify the timing of the period Ta during which uplink data transmission is not performed. When a plurality of TDD frames are prepared, the TDD frame varies depending on uplink and downlink traffic in the radio section. For this reason, the OLT 11 needs to periodically acquire TDD information.

FIG. 8 is a flowchart showing the flow of processing performed by the OLT 11 of the present invention. The process of FIG. 8 is performed when the ONU 13 is newly connected to the PON.
The BBU side interface 26 acquires TDD information from the BBU 14 (step S101). The TDD information acquired by the BBU side interface 26 is sent to the timing determination unit 27. The timing determination unit 27 determines the timing for performing the discovery process based on the acquired TDD information (step S102). The timing determination unit 27 controls the discovery processing unit 25 to perform discovery processing at the determined timing.

The discovery processing unit 25 determines whether or not the current timing is the timing determined by the timing determination unit 27 (step S103). When the current timing is not the timing determined by the timing determination unit 27 (step S103—NO), the discovery processing unit 25 repeatedly executes the process of step S103 until the timing determined by the timing determination unit 27 is reached. Note that the OLT 11 transmits data when there is uplink or downlink transmission data while the discovery process is not being performed.
On the other hand, when the current timing is the timing determined by the timing determination unit 27 (step S103—YES), the discovery processing unit 25 executes the discovery process (step S104).

  According to the OLT 11 configured as described above, the discovery window is set during a period in which uplink data transmission is not performed. Therefore, it is possible to perform discovery processing without affecting uplink data transmission at all, and it is possible to prevent a decrease in uplink data transfer efficiency due to discovery processing. That is, the OLT 11 acquires the timing information of the TDD frame, determines a period during which uplink data transmission is not performed based on the timing information of the TDD frame, and performs discovery processing. As a result, the discovery process can be performed in a period in which there is almost no uplink data. Therefore, it is possible to prevent deterioration in uplink communication efficiency.

<Modification>
In the mobile network 1 according to the first embodiment, the case where the number of ONUs 13 and RRHs 15 is three has been described as an example. However, two or less ONUs 13 and RRHs 15 may be connected to the mobile network 1, or four units. The above ONU 13 and RRH 15 may be connected.

<Second Embodiment>
FIG. 9 is a system diagram showing a system configuration of the mobile network 101 in the second embodiment of the present invention. In the second embodiment, a case where a PON is applied to a mobile backhaul will be described.

  The mobile network 101 in the second embodiment includes an OLT 111, a splitter 112, ONUs 113a to 113c, a representative base station 114, and base stations 115a to 115c. In FIG. 9, one end (upstream side) of the optical fiber 110 is connected to the OLT 111. A representative base station 114 is connected to the OLT 111. The other end (downstream side) of the optical fiber 110 is branched by the splitter 112 and connected to the ONUs 113a, 113b, and 113c. The ONU 113a is connected to the base station 115a, the ONU 13b is connected to the base station 115b, and the ONU 13c is connected to the base station 115c. In the following description, the ONUs 113a to 113c are described as ONUs 113 unless otherwise distinguished. In the following description, the base stations 115a to 115c will be described as the base station 115 unless otherwise distinguished.

  In this mobile network 101, for example, EPC (Evolved Packet Core) is used as a core network. The representative base station 114 responds to the EPC on behalf of each base station 115 connected to the ONU 113. Communication between the EPC and the base station 115 is performed via the representative base station 114.

FIG. 10 is a block diagram showing the configuration of the OLT 111 in the second embodiment of the present invention.
As shown in FIG. 10, the OLT 111 includes an NW-IF 121, a PON-IF 122, a downlink communication control unit 123, an uplink communication control unit 124, a discovery processing unit 125, a representative base station side IF 126, and a timing determination unit. 127.

The NW-IF 121 is an interface for transmitting and receiving signals to and from the representative base station 114 located on the upstream side of the own device.
The PON-IF 122 is an interface for transmitting and receiving signals to and from the ONU 13 located on the downstream side (for example, the PON side) of the own device.
The downlink communication control unit 123 buffers the downlink data, converts it into a PON frame, and transmits it.

The uplink communication control unit 124 buffers the uplink data and returns the PON frame to the original frame.
The discovery processing unit 125 performs discovery processing.
The representative base station side IF 126 is an interface for acquiring TDD information from the representative base station 114.
The timing determination unit 127 determines the timing for performing the discovery process based on the acquired TDD information.

  In the first embodiment, as illustrated in FIG. 3, the OLT 11 acquires TDD information from the BBU 14 by the BBU side interface 26. Then, the timing determination unit 27 controls the discovery processing unit 25 so that the discovery processing is performed in a period in which uplink data transmission is not performed.

  On the other hand, in the second embodiment, as shown in FIG. 10, the OLT 111 acquires TDD information from the representative base station 114 by the representative base station side IF 126. Then, the timing determination unit 127 controls the discovery processing unit 125 so that the discovery processing is performed in a period in which uplink data transmission is not performed. Other configurations (for example, the configuration of the ONU) are the same as those in the first embodiment, and thus description thereof is omitted.

  According to the OLT 111 configured as described above, the same effects as those of the first embodiment can be obtained.

<Modification>
In the mobile network 101 according to the second embodiment, the case where the number of ONUs 113 and base stations 115 is three has been described as an example. However, two or less ONUs 113 and base stations 115 may be connected to the mobile network 101. Four or more ONUs 113 and base stations 115 may be connected.

<Third Embodiment>
FIG. 11 is a block diagram showing the configuration of the OLT 211 in the third embodiment of the present invention. In the third embodiment, a case where a PON is applied to a mobile fronthaul will be described as in the first embodiment. That is, the system configuration in the third embodiment is the same as the system configuration in the first embodiment.

  As illustrated in FIG. 11, the OLT 211 includes an NW-IF 221, a PON-IF 222, a downlink communication control unit 223, an uplink communication control unit 224, a discovery processing unit 225, a TDD information extraction unit 226, and a timing determination unit. 227.

The NW-IF 221 is an interface for transmitting and receiving signals to and from the BBU 14 located on the upstream side of the own device.
The PON-IF 222 is an interface for transmitting and receiving signals to and from the ONU 13 located on the downstream side (for example, the PON side) of the own apparatus.
The downlink communication control unit 223 buffers the downlink data, converts it into a PON frame, and transmits it.

The uplink communication control unit 224 buffers the uplink data and returns the PON frame to the original frame.
The discovery processing unit 225 performs discovery processing.
The TDD information extraction unit 226 extracts TDD information from the downlink signal.
The timing determination unit 227 determines the timing for performing the discovery process based on the extracted TDD information.

  In the first embodiment, as shown in FIG. 3, the OLT 11 acquires TDD information from the BBU 14 by the BBU side interface 26. Then, the timing determination unit 27 controls the discovery processing unit 25 so that the discovery processing is performed in a period in which uplink data transmission is not performed.

  On the other hand, in the third embodiment, the TDD information extraction unit 226 extracts TDD information from the downlink signal. As shown in FIG. 2, the uplink and downlink communication ratios can be changed. For this reason, the BBU 14 periodically transmits uplink / downlink communication ratio information of the TDD frame to the terminal (wireless terminal). The TDD information extraction unit 226 extracts TDD information from the uplink / downlink communication ratio information of the downlink frame. The TDD information is subjected to error correction coding / OFDM (Orthogonal Frequency-Division Multiplexing) modulation and the like and transmitted from the BBU 14 to the terminal. Extract information. Then, the timing determination unit 227 controls the discovery processing unit 225 so that the discovery processing is performed in a period in which uplink data transmission is not performed. About another structure, it is the same as that of the above-mentioned 1st Embodiment.

  According to the OLT 211 in the third embodiment configured as described above, the same effects as in the first embodiment can be obtained. Also, unlike the first or second embodiment, in the third embodiment, there is no need to provide the BBU 14 with a mechanism for transmitting TDD information.

  The OLT in the first to third embodiments of the present invention can be applied not only to TDM-PON but also to TWDM (Time and wavelength division multiplexing) -PON OLT.

It should be noted that a program for realizing all or part of the ONT and ONU functions in the mobile networks 1 and 101 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system. The processing of each unit may be performed by executing. Here, the “computer system” includes an OS and hardware such as peripheral devices.
Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.

  The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

10, 110: optical fiber, 11, 50, 111, 211: OLT, 12, 112: splitter, 13 (13a-13c), 113 (113a-113c): ONU, 14: BBU, 15 (15a-15c): RRH, 21, 121, 221, 521: NW-IF, 22, 122, 222, 522: PON-IF, 23, 123, 223, 523: Downlink communication control unit, 24, 124, 224, 524: Uplink communication control , 25, 125, 225, 525: Discovery processing unit, 26: BBU side IF (BBU side interface) (acquisition unit), 27, 127, 227: Timing determination unit, 31: Radio system side IF, 32: PON- IF, 33: Downlink communication control unit, 34: Uplink communication control unit, 35: Register processing unit, 114: Table base station, 115 (115 a to 115 c): a base station, 126: representative base station IF (acquisition unit), 226: TDD information extraction unit (acquisition unit)

Claims (4)

Which are connected with division duplex radio system when a plurality of radio base stations, and a PON system including a subscriber optical network unit and station-side optical network unit communicating by time division duplex scheme A station side optical line terminating device in a wireless communication system,
From the information indicating which one of a plurality of types of frames having different uplink and downlink communication time ratios set in the time division duplex radio system is used, the uplink in the time division duplex radio system is used. An acquisition unit for acquiring time-division duplex information indicating communication timing between and downstream;
Based on the acquired time division duplex information, it is determined a period during which uplink data transmission is not performed in the optical communication section, and a new subscriber side optical line terminator and the station side optical line terminator A timing determination unit that determines the timing for executing discovery processing for establishing a connection;
A discovery processing unit that executes discovery processing at a determined timing;
A station side optical line terminating device. Constructed by connecting a time division duplex radio system having a plurality of radio base stations that perform communication by a time division duplex method and a PON system having a subscriber side optical line terminator and a station side optical line terminator. A station side optical line terminating device in a wireless communication system,
From the uplink / downlink communication ratio information of the communication by the time division duplex method included in the downlink signal transmitted from the radio base station to the radio terminal, the uplink and downlink in the time division duplex radio system An acquisition unit for acquiring time division duplex information indicating communication timing;
Based on the acquired time division duplex information, it is determined a period during which uplink data transmission is not performed in the optical communication section, and a new subscriber side optical line terminator and the station side optical line terminator A timing determination unit that determines the timing for executing discovery processing for establishing a connection;
A discovery processing unit that executes discovery processing at a determined timing;
A station side optical line terminating device. Which are connected with division duplex radio system when a plurality of radio base stations, and a PON system including a subscriber optical network unit and station-side optical network unit communicating by time division duplex scheme A discovery processing execution method performed by a station side optical line termination device in a wireless communication system,
From the information indicating which one of a plurality of types of frames having different uplink and downlink communication time ratios set in the time division duplex radio system is used, the uplink in the time division duplex radio system is used. An acquisition step of acquiring time-division duplex information indicating communication timing between and downstream;
Based on the acquired time division duplex information, it is determined a period during which uplink data transmission is not performed in the optical communication section, and a new subscriber side optical line terminator and the station side optical line terminator A timing determination step for determining a timing for executing a discovery process for establishing a connection;
A discovery process step for executing the discovery process at the determined timing;
A discovery processing execution method comprising: Constructed by connecting a time division duplex radio system having a plurality of radio base stations that perform communication by a time division duplex method and a PON system having a subscriber side optical line terminator and a station side optical line terminator. A discovery processing execution method performed by a station side optical line termination device in a wireless communication system,
From the uplink / downlink communication ratio information of the communication by the time division duplex method included in the downlink signal transmitted from the radio base station to the radio terminal, the uplink and downlink in the time division duplex radio system An acquisition step for acquiring time division duplex information indicating communication timing;
Based on the acquired time division duplex information, it is determined a period during which uplink data transmission is not performed in the optical communication section, and a new subscriber side optical line terminator and the station side optical line terminator A timing determination step for determining a timing for executing a discovery process for establishing a connection;
A discovery process step for executing the discovery process at the determined timing;
A discovery processing execution method comprising:

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