JP2017022514A - Master station communication device, optical communication network system and communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable high-speed and efficient communication at a connection using a star network, between a radio antenna device which is radio connected to a radio communication terminal and a signal processing device which is connected to the radio communication terminal through the radio antenna device.SOLUTION: A communication system includes a radio communication terminal, a radio antenna device, a signal processing device and an optical communication network system which connects between the radio antenna device and the signal processing device using the star network. A master station communication device, which configures the optical communication network system, permits a slave station communication device to transmit an uplink signal when receiving the uplink signal from the slave station communication device, and based on the communication control signal to the radio communication terminal extracted from a downlink signal, predicts an uplink signal to be transmitted from the radio communication terminal, so as to transmit, to the slave station communication device, the transmission permission of the uplink signal based on the prediction result.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a master station communication device, an optical communication network system, and a communication system, and is applied to, for example, a network in a wired section from a base station connected to a wireless communication terminal (for example, a mobile phone terminal) to an upper side (core side) Can do.

  There is a communication system called C-RAN (Centralized Radio Access Network) as a base station facility (communication facility on the communication carrier side) for connecting to a digital wireless communication terminal such as a conventional mobile phone.

  In C-RAN, the base station function is separated into BBU (Base Band Unit) that performs radio signal processing and a plurality of RRHs (Remote Radio Head) that are antenna parts, and both are usually directly connected by optical fiber. . Moreover, in C-RAN, it is set as the structure which accommodates several RRH with one BBU. In the C-RAN, by adopting such a configuration, only a large and heavy BBU is installed in a communication carrier building (for example, in a central office building), and a relatively light antenna part. (RRH) can be installed outdoors (for example, a utility pole or the rooftop of an apartment). Since the weight and space of devices that can be installed are limited due to the structure of utility poles and apartments, it is desirable that devices installed outdoors be smaller and lighter.

  Further, in the conventional C-RAN, a technology called COMP (Coordinated Multi-point) that reduces interference noise in cooperation between adjacent cells and terminals is applied. In C-RAN, CoS (Coordinated Scheduling) technology is particularly relevant. In C-RAN, for example, paying attention to the fact that the transmission power of RRH is much larger than the transmission power of the terminal, while the terminal is transmitting to the RRH to be communicated, the adjacent RRH stops the transmission by means of CoS (COMP) is realized.

  Further, in the conventional C-RAN, it is being considered to apply a PON (Passive Optic Network) that is a star network for communication between the BBU and the RRH. PON is a form of access network using optical fiber. By using a splitter, 1: N multi-branch optical fiber and time-division demultiplexing or wavelength demultiplexing technology, etc., a plurality of subscriber-side terminal devices (Optical Network Units) are used. : ONU) is accommodated by one station side terminal device (Optical Line Terminal: OLT).

  Conventionally, as a connection means for connecting RRH and BBU with C-RAN, a normal dedicated line (dedicated optical fiber for each RRH) has been used. It is possible to reduce the number of optical fibers and the distance to the joining side terminating device. Conventionally, as a technique in which PON is applied to C-RAN, for example, there is a technique described in Patent Document 1.

  In the technology described in Patent Document 1, each BBU-RRH section is configured by PON. That is, in the technique described in Patent Document 1, a PON OLT is connected to the BBU, and a PON ONU is connected to each RRH. Therefore, in the technique described in Patent Document 1, the BBU, the OLT, the ONU, the RRH, and the user terminal (hereinafter also referred to as “User Equipment” and “UE”) are connected in order from the upstream side.

  However, there are two problems in connecting RRH and BBU with PON. The first problem is that CPRI (Common Public Radio Interface), which is a signal format for connecting RRH and BBU in C-RAN, is a digital signal, but is close to a signal obtained by A / D conversion of an analog signal. Since it is not packet-based (not encoded), it cannot be transmitted as it is in PON. As a second problem, the bandwidth for transmitting CPRI needs to be about 10 times the substantial amount of information. Is a point.

  Conventionally, as a method for solving the above first problem, a fixed-band transmission line such as a dedicated line is provided by transmitting and receiving packets between the OLT and each ONU at a fixed period. There is a way. Conventionally, as a solution to the above-described second problem, there is a method in which a CPRI signal is losslessly compressed (encoded) and inserted into a packet such as Ethernet (registered trademark) to transmit a PON section. (See Patent Document 1). Furthermore, conventionally, as a solution to the above-described second problem, a method for performing more efficient data transmission by changing the amount and timing of packets transmitted and received by the PON in accordance with communication traffic between the RRH and the BBU. (See Patent Document 1).

JP 2014-103501 A

  However, in a communication system in which a conventional RRH and BBU are connected by a PON, every time an uplink signal is transmitted from the RRH (UE) to the BBU, communication control in the PON section (communication control between the ONU and the OLT). ) Occurs. For example, in a communication system that connects a conventional RRH and a BBU with a PON, when transmitting an uplink signal from the RRH (UE) to the BBU, the traffic amount to be transmitted from the RRH ONU is set as a REPORT signal in the OLT. In other words, a delay corresponding to the notification of the transmission possible time from the OLT to the ONU by the GRANT signal (GATE signal) occurs. That is, in the communication system in which the conventional RRH and BBU are connected by PON, in addition to the communication control between BBU and RRH, communication control in the PON section occurs, so compared with the case where PON is not used. As a result, communication delays and throughput decrease are likely to occur.

  In addition, when a packet signal used in communication between the OLT and each ONU is transmitted and received at a fixed period to provide a fixed-band transmission line such as a dedicated line, the ONU is always fixed. Since transmission / reception of a control signal for securing a band is performed in a short cycle, it is difficult to increase the sleep time. As a result, in the ONU, the power saving control is disadvantageous by securing the sleep time. In general, the power saving effect is higher when continuous transmission and continuous pause are performed in a long cycle.

  In view of the above problems, a signal for transmitting and receiving a signal between a wireless antenna device (for example, RRH) having a wireless antenna that transmits and receives a wireless signal to and from the wireless communication terminal, and a wireless communication terminal via the wireless antenna device. A master station communication device (for example, OLT), an optical communication network system (for example, PON), and communication that enable high-speed and efficient communication when connecting with a processing device (for example, BBU) by PON A system is desired.

  According to a first aspect of the present invention, there is provided between a plurality of wireless antenna devices having wireless antennas that transmit and receive wireless signals to and from a wireless communication terminal, and a signal processing device that performs transmission / reception processing of signals with the wireless communication terminal via the wireless antenna device. In the master station communication device constituting the optical communication network system that performs data transmission of (1), the slave station communication device connected to each of the wireless antenna devices is connected by PON and supplied from the signal processing device Processing the data and sending it as a downlink signal to the slave station communication device, and processing the uplink signal received from each slave station communication device and sending it to the signal processing device, A data transmission / reception processing unit for permitting upstream signal transmission to the slave station communication device when receiving an upstream signal from the station communication device; and (2) the data transmission / reception process. The communication control signal to the wireless communication terminal is extracted with reference to the downlink signal processed by the unit, the uplink signal transmitted from the wireless communication terminal is predicted based on the extracted communication control signal, and the prediction Based on the result, the transmission / reception processing unit is controlled to permit transmission of an uplink signal based on the prediction result to the slave station communication device corresponding to the slave station radio antenna device to which the radio communication terminal is connected. And a bandwidth control processing means for transmitting.

  According to a second aspect of the present invention, there is provided between a plurality of radio antenna apparatuses having radio antennas for transmitting and receiving radio signals to and from a radio communication terminal, and a signal processing apparatus for performing signal transmission / reception processing with the radio communication terminals via the radio antenna apparatus. In the optical communication network system in which the PON is connected by the PON, the slave station communication device connected to each of the wireless antenna devices and the signal processing device and the master station communication connected to each of the slave station communication devices by the PON An optical communication network system, wherein the master station communication device according to the first aspect of the present invention is applied as the master station communication device.

  According to a third aspect of the present invention, there is provided a radio communication terminal, a plurality of radio antenna apparatuses having radio antennas for transmitting / receiving radio signals to / from the radio communication terminal, and signal transmission / reception processing with the radio communication terminal via the radio antenna apparatus. In a communication system comprising a signal processing device that performs the above and an optical communication network system that connects each wireless antenna device and the master station communication device by PON, the optical communication network system according to the second aspect of the present invention is used. A communication system characterized by applying a communication network system.

  According to the present invention, a PON is provided between a wireless antenna device having a wireless antenna that transmits and receives wireless signals to and from a wireless communication terminal, and a signal processing device that performs transmission and reception processing of signals with the wireless communication terminal via the wireless antenna device. Enables high-speed and efficient communication when connecting.

It is the sequence shown about the example of operation of the communications system concerning an embodiment. 1 is a block diagram illustrating an overall configuration of a communication system according to an embodiment. It is the block diagram shown about the internal structure of each apparatus which comprises the communication system which concerns on embodiment, and the flow of data (signal).

(A) Main Embodiment Hereinafter, an embodiment of a master station communication device, an optical communication network system, and a communication system according to the present invention will be described in detail with reference to the drawings.

(A-1) Configuration of Embodiment FIG. 2 is a block diagram showing an overall configuration of the communication system 1 according to the embodiment.

  FIG. 3 is an explanatory diagram (block diagram) showing the internal configuration of each device constituting the communication system 1 and the flow of packets.

  The communication system 1 is a C-RAN type communication system that connects a UE 30 as a wireless communication terminal possessed by a user to a core-side network N.

  The communication system 1 includes a BBU 10 as a signal processing device arranged in a central office of a telephone station, and RRHs 20 (20-1, 20-2, 20-3) as three antenna devices connected under the control of the BBU 10. And have. In the communication system 1, each RRH 20 constitutes one cell C and is connected to the UE 20 in the cell C. In this embodiment, as shown in FIG. 2, the RRHs 20-1, 20-2, and 20-3 constitute cells C-1, C-2, and C-3, respectively. In this embodiment, the number of RRHs 20 (number of cells) connected under the control of the BBU 10 is not limited. Further, the BBU 10 is connected to a core side network N as an upper side network.

  In the communication system 1, the wired sections between the BBU 10 and the RRHs 20-1, 20-2, and 20-3 are connected by PON2 (optical communication network system). The PON 2 includes an OLT 40 (master station communication device) connected to the subordinate (downstream side) of the BBU 10 in the central office of the telephone station, and an ONU 50 (slave station communication device) connected to each RRH 20. In the PON 2, the optical fiber 60 connected to the OLT 40 is branched by the splitter 50 and connected to the ONUs 50-1, 50-2, and 50-3, respectively. In this embodiment, as shown in FIG. 2, ONUs 50-1, 50-2, and 50-3 are connected to RRHs 20-1, 20-2, and 20-3, respectively. That is, each ONU 50 is connected to the upstream side of each RRH 20 at the same location as the corresponding RRH 20 (for example, on the roof of a condominium or on a utility pole).

  Note that various PON and GE-PON (Gigabit Ethernet (registered trademark) -Passive Optical Network) interfaces (for example, interfaces defined in IEEE 802.3ah) are applied as the interfaces of the OLT 40 and the ONU 50 constituting the PON 2. Can do.

  That is, in the communication system 1, as shown in FIG. 2, the BBU 10, the OLT 40, the ONU 50, the RRH 20, and the UE 30 are connected in this order from the upstream side.

  In this embodiment, as illustrated in FIG. 3, the UE 30 includes a UE radio communication processing unit 31 and a UE application 32 for performing radio communication with the RRH 20. The UE 30 is a mobile communication terminal possessed by a user such as a smart phone or a mobile router. Note that various radio communication terminals can be applied as the UE 30. In this embodiment, the configuration shown in FIG. The UE 30 connects to a core side network (for example, a network such as the Internet) via the RRH 20 and the BBU 10. The UE application 32 is application software that functions by communicating with another communication device or server connected to the core side network N (or another network via the core side network N).

  Next, the internal configuration of the BBU 10 will be described with reference to FIG. As shown in FIG. 3, the BBU 10 of this embodiment includes an uplink packet configuration function 11, a downlink radio signal information configuration function 12, a statistical information holding function 13, a request RB reception function 14, an uplink necessary RB amount prediction function 15, and an RB allocation. A scheduling function 16 is provided. In FIG. 3, illustration of the configuration of the function of the BBU 10 that is not directly related to the data transmission process in the PON 2 section (for example, the handover control function related to the UE 30) is omitted.

  The uplink packet configuration function 11 processes an uplink signal received from the RRH 20 (UE 30) via the PON 2 from the RRH 20 (UE 30), and generates and transmits an uplink packet to be transmitted to the upstream side (core side network N). (Send to the core side network N). When sending the packet to the core side network N, the uplink packet configuration function 11 supplies a copy of the packet to the statistical information holding function 13 and the request RB reception function 14. The uplink packet configuration function 11 supplies the control signal transmitted to the own apparatus to the statistical information holding function 13 and the request RB reception function 14 without transmitting to the core side network N.

  The downlink radio signal information configuration function 12 processes a downlink packet received from the upstream side (core side network N) and transmits the data configuration of the radio signal to be transmitted to the UE 30 (RRH 20) (for example, encoded for radio communication). The data structure of the completed radio signal) and send it to the downstream side (OLT 40). That is, the downlink radio signal information configuration function 12 performs a process of transmitting the generated downlink radio signal data (information) to the RRH 20 (UE 30) via the PON 2.

  The statistical information holding function 13 calculates and holds the analysis of the supplied upstream packet (for example, the transition of the bandwidth used for each RRH 20).

  The request RB reception function 14 has a function of receiving a request for a resource block (hereinafter also referred to as “RB”) from each RRH 20 (each UE 30). RB is a unit for allocating a radio band as a resource. The BBU 10 receives an uplink RB request (hereinafter referred to as “uplink RB request”) from the UE 30, and performs a process of assigning an RB (uplink radio band) to the UE 30 according to the uplink RB request. That is, each UE 30 needs to acquire a notification (hereinafter referred to as “uplink RB notification”) that permits a predetermined amount of data transmission (uplink RB) from the BBU 10 when performing uplink data transmission. . When an upstream packet (data) is supplied from the upstream packet configuration function 11, the request RB reception function 14 performs processing for analyzing the upstream packet and extracting an upstream RB request.

  The uplink required RB amount prediction function 15 is requested from each UE 30 next based on, for example, the statistical information held by the statistical information holding function 13 and the history of the uplink RB request received by the request RB reception function 14. A process for predicting the RB amount in the upward direction is performed. Since various prediction algorithms can be applied to the prediction processing by the uplink necessary RB amount prediction function 15, detailed description thereof will be omitted.

  The RB allocation scheduling function 16 performs scheduling for allocating uplink RBs based on the prediction performed by the uplink necessary RB amount prediction function 15.

  Then, the downlink radio signal information configuration function 12 generates an uplink RB notification for allocating an uplink RB to each UE 30 based on the result of the scheduling performed by the RB allocation scheduling function 16 (uplink RB notification Generate a signal) and send it.

  Next, the internal configuration of the OLT 40 will be described.

  The OLT 40 includes a packet processing unit 41 as a data transmission / reception processing unit, a packet information duplication function 42, an uplink RB information extraction function 43, and a dynamic band allocation calculation function unit 44.

  The packet processing unit 41 processes the downstream packet supplied from the BBU 10 (converts it into a packet on the PON 2 destined for any one of the ONUs 5), and sends the packet to the PON 2. Further, the packet processing unit 41 processes a packet received from one of the ONUs 50 (converts it into a packet that can be transmitted to the BBU 10), and transmits the packet to the BBU 10.

  The packet processing unit 41 is, for example, a processing configuration related to dynamic bandwidth allocation (uplink RB information extraction function 43 and dynamic bandwidth allocation calculation function unit) among the packet processing configurations on GE-PON specified by IEEE 802.3ah. 44).

  The packet information duplication function 42 performs a process of duplicating a downlink packet supplied from the BBU 10 to the packet processing unit 41 and supplying the packet to the uplink RB information extraction function 43.

  The uplink RB information extraction function 43 performs processing for extracting the uplink RB notification from the packet (downlink packet from the BBU 10) supplied from the packet information replication function 42. Then, the uplink RB information extraction function 43 supplies the extracted uplink RB notification to the dynamic band allocation calculation function unit 44.

  The dynamic bandwidth allocation calculation function unit 44 performs bandwidth allocation for uplink data transmission to each ONU 50 on the PON 2 and controls the packet processing unit 41 so that the upstream signal from each ONU 50 is equal to or less than the allocated bandwidth. Perform the process. Specifically, the dynamic band allocation calculation function unit 44 transmits the GRANT signal (GATE signal) that the packet processing unit 41 transmits to each ONU 50 so that the uplink signal from each ONU 50 is equal to or less than the allocated band. And the content (the amount of uplink signal data permitted by each GRANT signal) is controlled. The specific method of dynamic bandwidth allocation performed by the dynamic bandwidth allocation calculation function unit 44 is not limited. For example, a DBA (Dynamic Bandwidth Allocation) algorithm on various GE-PONs is partially used. You may do it.

  The dynamic bandwidth allocation calculation function unit 44 also considers the contents of the REPORT signal received from the ONUs 50 by the packet processing unit 41 and the contents of the uplink RB notifications supplied from the uplink RB information extraction function 43, and each ONU 50. The process of assigning to is performed. Details of the process in which the dynamic bandwidth allocation calculation function unit 44 performs dynamic bandwidth allocation in consideration of the contents of the uplink RB notification will be described later.

  As described above, in the OLT 40, the bandwidth control processing means is realized by the uplink RB information extraction function 43 and the dynamic bandwidth allocation calculation function unit 44.

(A-2) Operation | movement of embodiment Next, operation | movement of the communication system 1 of this embodiment which has the above structures is demonstrated.

  FIG. 1 is a sequence diagram illustrating an example of the operation of the communication system 1.

  FIG. 1 shows an example in which UE 30 connected to cell C-1 configured by RRH 20-1 performs uplink data transmission.

  In FIG. 1, it is assumed that the initial connection between the OLT 40 and the ONU 50-1 is established in the initial state. Further, FIG. 1 will be described assuming that the initial connection between the BBU 10 and the RRH 20-1 is established in the initial state.

  In the initial state as described above, it is assumed that the UE 30 enters a state in which radio communication with the RRH 20-1 is possible and participates in the cell C-1, and a connection is established between the UE 30 and the BBU 10 (S101). Since the process similar to various C-RAN can be applied about the connection sequence between UE30 and BBU10 at this time, detailed description is abbreviate | omitted.

  Next, the uplink required RB amount prediction function 15 of the BBU 10 calculates an uplink RB expected to be necessary for the UE 30. In the BBU 10, the RB allocation scheduling function 16 performs adjustment and scheduling (determination of transmission time) for the RB predicted by the uplink necessary RB amount prediction function 15. At this time, the RB allocation scheduling function 16 determines the final RB amount for the UE 30 in consideration of the uplink RB expected for other terminals. Hereinafter, the amount of RB in the uplink direction finally determined by the RB allocation scheduling function 16 for the UE 30 is represented as “A”. As described above, the RB allocation scheduling function 16 determines the amount of RB to be allocated and the time (data transmission timing of the amount) based on the RB predicted to be necessary by the uplink necessary RB amount prediction function 15. . Then, the uplink RB notification in which the RB amount A determined by the RB allocation scheduling function 16 and the time is set is configured as a downlink signal by the downlink radio signal information configuration function 12, and is transmitted to the UE 30 (S102).

  Then, the uplink RB notification (amount A) addressed to the UE 30 reaches the UE radio communication processing unit 31 of the UE 30 via the OLT 40, the ONU 50-1, and the RRH 20-1 (S103 to S105).

  At this time, in the OLT 40, the packet processing unit 41 duplicates the uplink RB notification (amount A) addressed to the UE 30 and supplies it to the uplink RB information extraction function 43. Then, the uplink RB information extraction function 43 extracts the uplink RB notification (amount A) and transfers it to the dynamic band allocation calculation function unit 44. Then, the dynamic bandwidth allocation calculation function unit 44 allocates an upstream bandwidth (a bandwidth on the PON 2) corresponding to the amount A to the UE 30 (ONU 50-1) (S106). At this time, the dynamic bandwidth allocation calculation function unit 44 performs processing using a conversion formula for converting the amount of RB designated by the uplink RB notification into a unit on PON 2 (unit representing a bandwidth (data amount) on PON 2). May be performed. For example, the dynamic bandwidth allocation calculation function unit 44 may convert the RB amount (value) set in the uplink RB notification into a unit on the PON 2 by multiplying by a predetermined coefficient. At this time, the dynamic band allocation calculation function unit 44 considers the time set in the uplink RB notification, and the timing at which the ONU 50-1 transfers the data actually transmitted from the UE 30 (hereinafter, “expected transfer”). (Referred to as “timing”) may be predicted and reflected in the GRANT signal. For example, the dynamic bandwidth allocation calculation function unit 44 predicts and forwards a time obtained by adding a delay of a certain time to the time set for the uplink RB notification (a time after a certain time has elapsed from the time set for the uplink RB notification). You may make it set as a timing.

  Next, the packet processing unit 41 sends a GRANT signal (control signal) indicating that transmission of data in the bandwidth (data amount) allocated by the dynamic bandwidth allocation calculation function unit 44 is permitted at the expected transfer timing. It transmits to address (S107).

  On the other hand, in the UE application 32 of the UE 30, it is assumed that an event for performing uplink data transmission corresponding to an amount B of RBs has occurred. Then, the UE application 32 supplies data corresponding to the amount B to the UE radio communication processing unit 31 (S108).

  At this time, since the UE radio communication processing unit 31 has already acquired the uplink RB notification of the amount A, if the amount B <the amount A, all data transmission can be performed by one transmission. However, the following description will be made assuming that the quantity B> the quantity A. In this case, the UE radio communication processing unit 31 determines to transmit data to the BBU 10 by the amount A and to transmit an uplink RB request that requests an RB of the amount B-A that is insufficient. Become. In this case, in the UE radio communication processing unit 31, traffic data corresponding to the amount B-A remains.

  Therefore, here, when the UE 30 (UE radio communication processing unit 31) performs the data transmission of the amount A to the BBU 10 at the time specified by the uplink RB notification, the uplink RB request for the amount B-A is performed. Is added (S109). The uplink RB request (amount B−A) is treated as additional information for the amount A data transmission, and will be described below assuming that transmission is possible within the range of the amount A data transmission.

  Then, the data (amount A) transmitted from the UE 30 reaches the BBU 10 via the RRH 20-1, the ONU 50-1, and the OLT 40 (S110 to S112).

  At this time, since the ONU 50-1 has already obtained the permission (GRANT) of data transmission corresponding to the amount A of RB from the OLT 40 in the above-described step S107, a separate permission (REPORT signal is transmitted to the OLT 40 to separately separate the GRANT). It is not necessary to perform processing to acquire the. Therefore, at this time, when the ONU 50-1 acquires the data (amount A) transmitted from the UE 30, it becomes possible to transmit the data to the OLT 40 without delay.

  In the BBU 10, predetermined processing (for example, upstream packet generation processing) is performed on the amount A of data supplied from the UE 30 by the upstream packet configuration function 11. At this time, the request RB reception function 14 extracts the uplink RB request from the UE 30 and supplies it to the uplink necessary RB amount prediction function 15. Then, the uplink necessary RB amount prediction function 15 and the RB allocation scheduling function 16 determine the amount of uplink RB and the time of the uplink RB in consideration of the uplink RB request (insufficient amount BA). At this time, the amount of RB in the uplink direction finally determined by the RB allocation scheduling function 16 is represented as “C”. Then, the uplink RB notification in which the RB amount C determined by the RB allocation scheduling function 16 and the time is set is configured as a downlink signal by the downlink radio signal information configuration function 12, and is transmitted to the UE 30 (S113).

  Then, the uplink RB notification (quantity C) addressed to the UE 30 reaches the UE radio communication processing unit 31 of the UE 30 via the OLT 40, the ONU 50-1, and the RRH 20-1 (S114 to S116).

  At this time, the dynamic band allocation calculation function unit 44 of the OLT 40 allocates an uplink band corresponding to the uplink RB notification (amount C) to the UE 30 as in step S106 described above (S117).

  Next, the packet processing unit 41 sends a GRANT signal (control signal) indicating that transmission of data in the bandwidth (data amount) allocated by the dynamic bandwidth allocation calculation function unit 44 is permitted at the expected transfer timing. It transmits to address (S118).

  And UE30 (UE radio | wireless communication process part 31) performs data transmission of quantity BA to BBU10 at the time designated by the uplink RB notification (S119). Here, it is assumed that C> (B−A) and the UE radio communication processing unit 31 does not have an insufficient amount of RB.

  Then, the data (amount BA) transmitted from the UE 30 reaches the BBU 10 via the RRH 20-1, the ONU 50-1, and the OLT 40 (S120 to S122).

  At this time, since the ONU 50-1 has already obtained the data transmission permission (GRANT) corresponding to the amount C of RB from the OLT 40 in the above-described step S118, the data (amount B-A) transmitted from the UE 30 is obtained. When acquired, the data can be transmitted to the OLT 40 without delay.

(A-3) Effects of Embodiment According to this embodiment, the following effects can be achieved.

  In the communication system 1, the OLT 40 acquires and analyzes the content of the uplink RB notification transmitted from the BBU 10 to the UE 30, and based on the analysis result, the GRANT signal that preallocates the band (data amount) required by the UE 30 Is transmitted to the corresponding ONU 50 (the ONU 50 related to the RRH 20 to which the UE 30 is connected) (see, for example, steps S106 and S107 in FIG. 1). As a result, the ONU 50 uses the data transmission permission (GRANT) acquired from the OLT 40 in advance and transmits the data without delay even when uplink data transmission is performed in accordance with the uplink RB notification from the UE 30. It is possible to transmit to the OLT 40 (see, for example, step S111 in FIG. 1).

  Here, it is assumed that the OLT 40 does not perform the process of transmitting the GRANT signal in advance based on the uplink RB notification. In this case, the ONU 50 acquires the data transmitted from the UE 30, and then transmits a REPORT signal requesting uplink data transmission (requesting an uplink band (resource)) to the OLT 40, and the OLT 40 transmits the REPORT signal. After obtaining the GRANT signal (permission of uplink data transmission) corresponding to the data transmission, data transmission can be started for the first time. On the other hand, the ONU 50 of the communication system 1 of this embodiment only needs to transfer the data from the UE 30 according to the GRANT signal acquired in advance, so that the upstream data transfer processing can be performed without delay (very high efficiency). It can be carried out.

  Further, in the communication system 1 of this embodiment, since only the necessary data is transferred when necessary, instead of periodically communicating between the OLT 40 and the ONU 50, the sleep time of the ONU 50 is consequently increased. This makes it possible to perform a power saving operation. For example, when a transmission line having a fixed band such as a dedicated line is provided by transmitting and receiving packets between the OLT 40 and each ONU 50 at a fixed period, it is difficult to take a long sleep time for the ONU 50. However, as in this embodiment, the ONU 50 can be efficiently operated by securing the upstream bandwidth based on the upstream RB notification, thereby ensuring a longer sleep time.

  Furthermore, in the communication system 1 of this embodiment, the OLT 40 only duplicates and analyzes the downstream signal from the BBU 10 and secures the upstream signal bandwidth with the ONU 50 prior to the upstream signal from the UE 30. For the BBU 10 and the RRH 20, a device corresponding to the conventional C-RAN can be applied as it is. In other words, as viewed from the BBU 10 and the RRH 20, the section of the PON 2 can be viewed as a simple transmission path, and thus can communicate transparently without being aware of its existence. Therefore, for example, even when BBU10 and RRH20 exist as existing equipment, it is necessary to insert PON2 into the wired section later (or replace the PON in the existing wired section with PON2 of this embodiment). Each effect described above can be achieved.

(B) Other Embodiments The present invention is not limited to the above-described embodiments, and may include modified embodiments as exemplified below.

  (B-1) In the above embodiment, the configuration in which the PON 2 transmits between the BBU 10 and the RRH 20 compliant with the C-RAN has been described. However, the PON 2 is not limited to the C-RAN, and various wireless base stations ( It can be applied to data transmission in a wired section of a base station separated into an antenna device and a signal processing device.

  DESCRIPTION OF SYMBOLS 1 ... Communication system, 2 ... PON, 10 ... BBU, 11 ... Uplink packet structure function, 12 ... Downlink radio signal information structure function, 13 ... Statistical information holding function, 14 ... Request RB reception function, 15 ... Expected uplink RB amount Functions: 16 ... RB allocation scheduling function, 40 ... OLT, 41 ... packet processing unit, 42 ... packet information replication function, 43 ... uplink RB information extraction function, 44 ... dynamic bandwidth allocation calculation function unit, 50 ... splitter, 60 ... Optical fiber, 50, 50-1, 50-2, 50-3 ... ONU, 20, 20-1, 20-2, 20-3 ... RRH, 30 ... UE, 31 ... UE radio communication processing unit, 32 ... UE Application, N ... core side network, C, C-1, C-2, C-3 ... cell.

Claims (5)

Optical communication that performs data transmission between a plurality of wireless antenna devices having wireless antennas that transmit and receive wireless signals to and from a wireless communication terminal, and a signal processing device that performs signal transmission and reception processing with the wireless communication terminals via the wireless antenna device In the master station communication device constituting the network system,
Processing connected to each slave station communication device connected to each wireless antenna device by a star network, processing data supplied from the signal processing device and sending it as a downlink signal to the slave station communication device; And processing the uplink signal received from each of the slave station communication devices and transmitting it to the signal processing device. When receiving the uplink signal from the slave station communication device, the slave station communication device A data transmission / reception processing unit for permitting uplink signal transmission to
The communication control signal to the wireless communication terminal is extracted with reference to the downlink signal processed by the data transmission / reception processing unit, and the uplink signal transmitted from the wireless communication terminal is predicted based on the extracted communication control signal. Based on the result of the prediction, the data transmission / reception processing unit is controlled to transmit the uplink signal based on the result of the prediction to the slave station communication device corresponding to the wireless antenna device to which the wireless communication terminal is connected. A base station communication device comprising: bandwidth control processing means for transmitting a transmission permission.   Referring to the downlink signal processed by the data transmission / reception processing unit, obtains a resource allocation notification signal related to uplink signal transmission to the radio communication terminal, and based on the acquired resource allocation communication signal, the radio communication terminal 2. The parent signal according to claim 1, wherein a data amount of an uplink signal transmitted from the mobile station is predicted, and an uplink signal transmission permission in consideration of the predicted uplink signal data amount is transmitted in advance to the slave station communication device. Station communication device.   Referring to the downlink signal processed by the data transmission / reception processing unit, obtains a resource allocation notification signal related to uplink signal transmission to the radio communication terminal, and based on the acquired resource allocation communication signal, the radio communication terminal A data amount and transmission timing of an uplink signal transmitted from the mobile station, and a transmission permission of the uplink signal in consideration of the predicted data amount and transmission timing of the uplink signal is transmitted in advance to the slave station communication device. The master station communication device according to claim 1. A plurality of wireless antenna devices each having a wireless antenna that transmits and receives wireless signals to and from a wireless communication terminal and a signal processing device that performs signal transmission and reception processing with the wireless communication terminal via the wireless antenna device are connected by a star network. In optical communication network system,
A slave station communication device connected to each of the wireless antenna devices, a master station communication device connected to the signal processing device and connected to each slave station communication device via a star network,
An optical communication network system, wherein the master station communication device according to claim 1 is applied as the master station communication device.   A wireless communication terminal, a plurality of wireless antenna devices having wireless antennas that transmit and receive wireless signals to and from the wireless communication terminal, a signal processing device that performs signal transmission and reception processing with the wireless communication terminal via the wireless antenna device, 5. The optical communication network system according to claim 4 is applied as the optical communication network system in a communication system including an optical communication network system that connects each of the wireless antenna devices and the master station communication device by a star network. A communication system characterized by that.

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