JP2010206752A - Communication system, station-side device and high-order communication equipment, and band control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a PON (Passive Optical Network) system capable of effectively utilizing communication bands of a high-order network. <P>SOLUTION: A station-side device 107 includes: an uplink signal time allocation section 151 for allocating the time for transmitting data from a plurality of subscriber-side devices to the station-side device; a use band calculation section 152 for calculating the total use bands required for communication with a high-order communication equipment by obtaining bands to be used in an uplink direction of a PON interval for communicating with each subscriber-side device via a PON interface from the allocation time of the uplink signal time allocation section and a communication speed of each subscriber-side device; and a band information notification section 153 for notifying the high-order communication equipment of the calculated use band information via a high-order network interface. The high-order communication equipment 108 includes: a band information receiving section 154 for receiving the use band information notified from each of a plurality of band notification sections; and an output route determining section 155 for determining an output route for transmission to a high-order network based on a plurality of use band information items received by the band information receiving section. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a bandwidth control technique for a communication system provided with a PON (Passive Optical Network) system having a plurality of communication speeds.

  In recent years, broadband access services using optical fibers have become widespread. Such a communication system is a system in which an optical fiber is connected between a station side device and a subscriber side device, and an OLT (optical line station side termination device) is arranged on the station side, and the subscriber side Is provided with an ONU (optical line subscriber side device). The OLT and ONU connection methods include a single star method in which the OLT and the ONU are connected in a one-to-one relationship, and a double star method in which the OLT and the ONU are connected in a one-to-n relationship. The PON system is a system using a double star system that is connected in a 1: n relationship. The PON system includes an STM-PON system that communicates between the OLT and the ONU by an STM method (synchronous method), a B-PON system and an A-PON system that communicates by an ATM method (asynchronous method), and It is roughly classified into an E-PON system and a GE-PON system that communicate by Ethernet (registered trademark). In such a PON system, effective use of the communication band is a major issue, and various methods are being studied (see, for example, Patent Document 1).

  Recently, a 10G-EPON system that communicates at an ultra-high speed of 10 Gbps from a 1 Gbps EPON system has also been realized, and it is required to efficiently use a communication band even in a situation where a plurality of communication speeds are used together. Has come to be.

JP 2008-053793 A

  However, in an EPON system in which a plurality of communication speeds are mixedly used, there is a problem that a higher communication band is not always effectively used. FIG. 8 is a configuration example of the PON system 401 when a plurality of communication speeds coexist. The EPON system 401 in FIG. 8 includes a GE-PON-compatible ONU (subscriber side device) 402 with an uplink communication speed of 1 Gbps and a downlink communication speed of 10 Gbps, an uplink communication speed of 1 Gbps, and a downlink communication speed of 10 Gbps. ONU 403 compatible with 10 / 1G-EPON, ONU 404 compatible with 10 / 10G-EPON with both upstream and downstream communication speeds of 10 Gbps, optical coupler 405, OLT (station side device corresponding to 10G-EPON with dual-rate) ) 406.

  In FIG. 8, the ONU 402, the ONU 403, and the ONU 404 are normally assigned an upstream signal transmission time t at equal intervals from the OLT 406 side to each ONU, and each ONU transmits an upstream signal to the OLT 406 by the TDMA method with different transmission times. It has become. For example, transmission frame A of ONU 402, transmission frame B of ONU 403, and transmission frame C of ONU 404 are transmitted to OLT 406 in time division in order. The order of transmission is controlled by the OLT 406. The optical coupler 405 is a passive element for branching the downstream signal transmitted from the OLT 406 to each ONU and conversely sending the upstream signal transmitted from each ONU to the OLT 406. Further, optical signals having different wavelengths are used for the upstream signal and the downstream signal.

  As described above, since transmission times of equal intervals are normally assigned to each ONU, when a plurality of ONUs having the same communication speed are used, for example, the PON system 411 used in the communication system 410 of FIG. Since the communication bandwidth allocated to each ONU is equally divided, the communication bandwidth of 10 Gbps higher than the OLT 418 is used to the maximum efficiency. Here, the communication speed and communication band used in this description are defined. With regard to the communication speed, for example, the upstream communication speed of each of the ONUs 412 to 416 in FIG. 9 is 10 Gbps, but the substantial communication speed when the transmission time is 1/5 is 2 Gbps. Therefore, in the description of the present specification, unless otherwise specified, a physical speed at which communication can be performed by individual devices and paths is referred to as a communication speed, and a substantial communication speed in consideration of transmission time is referred to as a communication band. .

  For example, in the PON system 411 of FIG. 9, five ONUs corresponding to 10 / 10G-EPON (ONU 412 to ONU 416) having both uplink and downlink communication speeds of 10 Gbps are connected to the OLT 418 corresponding to 10G-EPON via the optical coupler 417. In addition, it is connected to the host communication device 419 via a 10 Gbps IF (10G-IF (interface)). Since the OLT 418 divides and assigns the transmission times of the five ONUs from the ONU 412 to the ONU 416 at equal intervals, the communication bandwidth of each ONU is 10 Gbps / 5 units = 2 Gbps / unit. From the OLT 418 to the higher-level communication device 419, the transmission data of the five ONUs are collected and data with a communication bandwidth of 2 Gbps × 5 units = 10 Gbps is transmitted. The host communication device 419 that accommodates a plurality of similar OLTs has a plurality of output routes (10G and 100G interfaces) that are connected to a host network. For example, the host communication device 419 sends the OLT 418 to the host communication device 419. Since the data of the 10 Gbps communication band is output as it is, for example, to the 10 Gbps output route, the communication bandwidth of the output route connected to the higher level network from the higher level communication device 419 can be effectively used 100%. .

  However, in the case of an EPON system in which ONUs having a plurality of communication speeds coexist, there arises a problem that the communication band to the higher-level communication device 419 is not effectively used. For example, in the PON system 421 of the communication system 420 shown in FIG. 10, ONUs 422, 423, 424 and 425 having an uplink communication speed of 1 Gbps and ONU 426 having an uplink communication speed of 10 Gbps are mixed. These upstream signals of two communication speeds of 1 Gbps and 10 Gbps are connected to the OLT 418 corresponding to 10G-EPON via the optical coupler 417 as in the case of the PON system 411 in FIG. 9, and further communicated with the host via the IF of 10 Gbps. Connected to device 419. Here, the same reference numerals as those in FIG. 9 denote the same components. Also in the PON system 421 of FIG. 10, the OLT 418 assigns transmission intervals at equal intervals to the five ONUs from the ONU 422 to the ONU 426. Therefore, when the communication speed is the same, the upstream communication bandwidth of each ONU is 1/5. become. For example, since the ONU 422 to ONU 425 have a communication speed of 1 Gbps, the communication bandwidth is 200 Mbps in the case of the transmission time of 1/5. On the other hand, since the ONU 426 has a communication speed of 10 Gbps, the communication bandwidth is 2 Gbps in the case of 1/5 of the communication time. As a result, the upstream signals from the five ONUs aggregated to the OLT 418 via the optical coupler 417 become 2.8 Gbps, and 2.8 Gbps data is transmitted from the OLT 418 to the host communication device 419. Then, the upper communication apparatus 419 accommodating a plurality of similar OLTs outputs the data of the 2.8 Gbps communication band sent from the OLT 418 to any one of a plurality of output routes connected to a higher network as it is. . In other words, for example, data in the 2.8 Gbps communication band is output to the output route in the 10 Gbps communication band, and therefore, the communication band in the output route connected to the upper network from the upper communication device 419 is not effectively used. Problems arise.

  Thus, in the case of a communication system having a PON system in which a plurality of communication speeds coexist, there is a problem that the communication band of the upper network cannot be effectively used.

  An object of the present invention is to provide a communication system, a station-side device, a higher-level communication device, and a bandwidth that can effectively use the communication bandwidth of a higher-level network even in the case of a communication system having a PON system in which a plurality of communication speeds are mixed. It is to provide a control method.

  A communication system according to the present invention includes a host communication device connected to a host network, a plurality of station side devices connected to the host communication device, and a plurality of subscriber side devices accommodated in the station side device. In a communication system comprising a PON system in which a plurality of communication speeds are mixed between the station-side device and the plurality of subscriber-side devices, the station-side device includes the plurality of communication devices. PON interface for connecting a subscriber side device, an upper network interface for connecting to the higher order communication device, and an upstream signal time for assigning a data transmission time for transmitting data from the plurality of subscriber side devices to the station side device An allocation unit, and the uplink signal time allocation unit allocating each usage band in the uplink direction of the PON section communicating with each subscriber side device via the PON interface. Obtained from time and the communication speed of each of the subscriber side devices, a used bandwidth calculation unit for calculating a total used bandwidth necessary for communication with the higher-level communication device, and the used bandwidth obtained by the used bandwidth calculation unit A bandwidth information notification unit for notifying the host communication device of information via the host network interface, wherein the host communication device is notified of the used bandwidth information respectively from the bandwidth notification units of the plurality of station side devices. A band information receiving unit that receives the received band information, and an output route determining unit that determines an output route when transmitting to the upper network from the used band information of the plurality of station side devices received by the band information receiving unit. It is provided.

  Preferably, the output route determination unit is configured to determine whether the plurality of station-side devices have uplinks based on the use band information so that the use ratio of the communication band of the output route to the upper network is maximized. A combination of directional communication bands is determined.

  The station side device of the communication system according to the present invention includes a host communication device connected to a host network, a plurality of station devices connected to the host communication device, and a plurality of subscribers accommodated in the station device. A communication system configured with a side device, wherein the station side device of the communication system constituting a PON system in which a plurality of communication speeds are mixed between the station side device and the plurality of subscriber side devices, The PON interface for connecting the plurality of subscriber side devices, the host network interface for connecting to the higher order communication device, and the data transmission time for transmitting data from the plurality of subscriber side devices to the station side device are allocated. An upstream signal time allocation unit, and each upstream use band in the upstream direction of a PON section communicating with each of the subscriber side devices via the PON interface Obtained from the allocated time of each part and the communication speed of each of the subscriber side devices, and the used bandwidth calculating unit for calculating the total used bandwidth necessary for communication with the host communication device, and the used bandwidth calculating unit A bandwidth information notification unit that notifies the higher-level communication device of the used bandwidth information via the higher-level network interface.

  The host communication device of the communication system according to the present invention includes a host communication device connected to a host network, a plurality of station side devices connected to the host communication device, and a plurality of subscribers accommodated in the station side device. In the higher-level communication device of the communication system constituting a PON system in which a plurality of communication speeds are mixed between the station-side device and the plurality of subscriber-side devices. A band information receiving unit that receives the used band information respectively notified from the band notifying unit of the plurality of station side devices, and a higher rank from the used band information of the plurality of station side devices received by the band information receiving unit And an output route determining unit that determines an output route when transmitting to the network.

  Preferably, the output route determination unit is configured to determine whether the plurality of station-side devices have uplinks based on the use band information so that the use ratio of the communication band of the output route to the upper network is maximized. A combination of directional communication bands is determined.

  A bandwidth control method for a communication system according to the present invention includes a host communication device connected to a host network, a plurality of station side devices connected to the host communication device, and a plurality of subscribers accommodated in the station side device. Communication system band used in a communication system composed of a side device and constituting a PON (Passive Optical Network) system in which a plurality of communication speeds are mixed between the station side device and the plurality of subscriber side devices In the control method, the station side device connects an uplink signal time allocation procedure for assigning a data transmission time for transmitting data from the plurality of subscriber side devices to the station side device, and the plurality of subscriber side devices. In the upstream signal time allocation procedure, each bandwidth used in the upstream direction of the PON section communicating with each of the subscriber side devices via the PON interface Obtained from the assigned time allocated and the communication speed of each of the subscriber side devices, and obtained by the used bandwidth calculating procedure for calculating the total used bandwidth required for communication with the higher-level communication device, and the used bandwidth calculating procedure. A bandwidth information notification procedure for notifying the higher-level communication device via the higher-level network interface that connects the used bandwidth information to the higher-level communication device, wherein the higher-level communication device includes the bandwidth notification of the plurality of station-side devices. Bandwidth information receiving procedure for receiving the used bandwidth information notified from each of the units, and an output route when transmitting the used bandwidth information of the plurality of station side devices received in the bandwidth information receiving procedure to a higher-level network And an output route determination procedure for determining the output route.

  Preferably, in the output route determination procedure, based on the use band information, the uplink of the plurality of station side devices is maximized so that the use ratio of the communication band of the output route to the upper network is maximized. A combination of directional communication bands is determined.

  The communication system, the station-side device, the higher-level communication device, and the bandwidth control method according to the present invention transmit the bandwidth information from the OLT to the higher-level communication device even in the case of a communication system having a PON system in which a plurality of communication speeds are mixed. Since the output route to the other network is controlled, the communication band of the upper network can be used effectively. As a result, since the current optical fiber network can be used efficiently, the addition of new optical fiber cables can be suppressed as much as possible, and the cost of the communication system can be reduced. In particular, it is possible to minimize the establishment of a new high-speed network in the network higher than the OLT.

1 is a diagram illustrating a configuration of a communication system 100 according to a first embodiment. It is a block diagram of OLT107 of the communication system 100 concerning 1st Embodiment. It is a figure explaining the output route determination part of the high-order communication apparatus 108 of the communication system 100 which concerns on 1st Embodiment. It is a figure which shows the structure of the communication system 200 which concerns on 2nd Embodiment. It is a figure which shows the actual example of the communication system 200 which concerns on 2nd Embodiment. It is a figure which shows the structure of the communication system 300 which concerns on 3rd Embodiment. It is a figure which shows the structure of the communication system 350 which concerns on 4th Embodiment. 1 is a diagram illustrating a configuration of a general PON system 401. FIG. It is a figure which shows the conventional communication system 410. FIG. It is a figure which shows the conventional communication system 420. FIG.

  Hereinafter, a first embodiment of a communication system, a station-side device, a host communication device, and a bandwidth control method according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration of a communication system 100 according to the first embodiment. In FIG. 1, a PON system 101 includes ONUs 102 and 103 having an uplink communication speed of 1 Gbps and ONUs 104 and 105 having an uplink communication speed of 10 Gbps. Then, these two uplink signals of 1 Gbps and 10 Gbps are connected to the 10G-EPON compatible OLT 107 via the optical coupler 106 and further connected to the host communication device 108 via the 10 Gbps IF. Here, in the PON system 101, as described in the prior art, since the OLT 107 allocates transmission intervals at equal intervals to the four ONUs from the ONU 102 to the ONU 105, the upstream communication bandwidth of each ONU is 1 communication speed. / 4. For example, since ONUs 102 and 103 have a communication speed of 1 Gbps, the communication band is 250 Mbps. On the other hand, since the ONUs 104 and 105 have a communication speed of 10 Gbps, the communication band is 2.5 Gbps. Here, in this embodiment, the OLT 107 calculates a use band of data to be transmitted to the higher-level communication device 108 (use band calculation unit 152). Then, the information on the calculated use band is notified to the higher-level communication device 108 (band information notification unit 153). For example, in the case of FIG. 1, the use band of data transmitted from the OLT 107 to the higher-level communication apparatus 108 is the communication band of the total uplink signal from the four ONUs aggregated to the OLT 107 via the optical coupler 106. 5 Gbps.

  On the other hand, the higher-level communication device 108 receives the used band information sent from the band information notifying unit 153 of the OLT 107 and the used band information sent from other similar OLTs accommodated in the subordinate (band information receiving unit). 154), an output route is determined from the received band information (output route determination unit 155). For example, in the case of FIG. 1, when the bandwidth information sent from the OLT 107 is 5.5 Gbps and the bandwidth information sent from the other OLT 127 and OLT 137 is 2.8 Gbps and 10 Gbps, respectively, the higher-level communication device 108 The output route determination unit 155 determines a combination that can make maximum use of the bandwidth 10 Gbps of the output route connected to the higher-level network. The 10 Gbps of OLT137 is output as it is to the output route of the 10 Gbps band, but if the data of 5.5 Gbps of OLT107 and the 2.8 Gbps data of OLT127 are output to the output route of the 10 Gbps band respectively, a large unused band is generated. , OLT 107 and OLT 207 are time-division multiplexed on one 10 Gbps output route and output. As a result, since 8.3 Gbps can be used in the communication band of 10 Gbps, effective use of the communication band can be achieved.

  In the above example, for the sake of clarity, the description has been made with three bands of 2.8 Gbps, 5.5 Gbps, and 10 Gbps. However, even when a plurality of OLTs of various communication bands are connected, the output route Similarly, the determination unit 155 can determine the output route by selecting a combination that can utilize the communication bandwidth of the output route to the maximum. For example, when the host communication device accommodates an OLT having communication bandwidths of 2 Gbps, 4 Gbps, 6 Gbps, and 8 Gbps, the communication bandwidth of the 10 Gbps output route is made as effective as possible without selecting the combination of 2 Gbps and 4 Gbps or 2 Gbps and 6 Gbps. In order to be able to use, it is determined to be a combination of 4 Gbps and 6 Gbps OLT and a combination of 4 Gbps and 6 Gbps OLT.

  Here, FIG. 3 shows a configuration centering on the host communication device 108 of the communication system 100 of FIG. 2 and a plurality of OLTs connected thereto. Note that the OLT 207 and the OLT 307 have the same configuration as the OLT 107 described with reference to FIG. 2, and the upper communication apparatus 108 is notified of usage band information from each of the OLT 107, the OLT 207, and the OLT 307. The upper communication device 108 is a communication device corresponding to a normal network switch or the like, and transmits data sent from the lower OLT side to the upper network, and receives data sent from the upper network as a destination. It has a function of routing to the OLT. The higher-level communication apparatus 108 of this embodiment has a band information receiving unit 154 and an output route determining unit 155 that are sent from the OLT side.

  The band information receiving unit 154 receives the used band information transmitted from each accommodated OLT and outputs the received band information to the output route determining unit 155. Note that the bandwidth information receiving unit 154 may instruct each OLT to notify the bandwidth usage information by polling each OLT. Alternatively, it is only necessary to wait for use band information from each OLT.

  The output route determination unit 155 aggregates the used bandwidth information of each OLT received by the bandwidth information reception unit 154 and determines an output route to a higher network. As described above with reference to FIG. 1, the output route is determined by selecting a combination of OLT upstream signals that can utilize the communication bandwidth of the output route to the maximum.

  The output route determination unit 155 includes a register that holds communication bandwidth information of an output route connected to a higher-level network, use bandwidth information transmitted from each OLT, and the like. Also, these registers are updated as needed periodically or when there is a change.

  Next, the configuration of the OLT 107 will be described in detail with reference to FIG. In FIG. 2, the OLT 107 includes a WDM unit (wavelength multiplexing communication unit) 161, an optical / electrical signal conversion unit 162, a SERDES unit 163, a PON control unit 164, an upper network IF (interface) 165, and a control system 166. And a power supply unit 167.

  The WDM unit 161 provides a PONIF (PON interface) for connecting a plurality of ONUs, and is communicated by wavelength multiplexing using different wavelengths for upstream signals from each ONU to the OLT 107 and downstream signals from the OLT 107 to each ONU. The

  The photoelectric signal conversion unit 162 converts an optical signal received from the ONU side via the WDM unit 161 into an electrical signal (O / E conversion), and converts the electrical signal sent from the upper network side to light of a predetermined wavelength. This corresponds to a so-called optical transceiver that converts a signal (E / O conversion) and transmits it to the ONU side.

  The SERDES unit 163 converts the serial data output from the photoelectric signal conversion unit 162 into parallel data and outputs the parallel data to the PON control unit 164. Conversely, the SERDES unit 163 converts parallel data output from the PON control unit 164 into serial data. This is a circuit that outputs to the photoelectric signal converter 162.

  The PON control unit 164 includes an uplink signal time allocation unit 151, a used band calculation unit 152, and a band notification unit 153 that are features of the present embodiment. These configurations will be described in detail later.

  The host network IF 165 is an interface for connecting to the host communication device 108 and the like.

  The control system 166 includes an operation interface such as a storage unit and a power button for controlling the operation of the entire OLT 107 and storing operation parameters. The power supply unit 167 supplies operation power to each unit of the OLT 107.

  Next, the configuration of the PON control unit 164 will be described in detail. The uplink signal time allocation unit 151 grasps the number of connected ONUs, etc., from the training signal that is used when communication with the subordinate OLT is started, and sends out data that each ONU sends to the OLT 107 side according to the number of the ONUs. The timing is instructed to each ONU via the SERDES unit 163, the photoelectric signal conversion unit 162, and the WDM unit 161. Each ONU transmits uplink data at a timing instructed by the OLT 107. Here, in the first embodiment, it is assumed that the transmission time is equally divided by the number of connected ONUs. For example, if there are 3 ONUs, 1/3 transmission time is assigned to each ONU, and if 6 ONUs, 1/6 transmission time is assigned to each ONU.

  Based on the time allocated to each ONU by the uplink signal time allocation unit 151 and the communication speed of each ONU, the used band calculation unit 152 first obtains the communication band of each ONU. As described above, when the communication speed of the ONU is 1 Gbps and five ONUs are connected, the communication bandwidth is 200 Mbps because the transmission time is 1/5. The communication speed of each ONU can be known from the ONU ID and the ONU clock information obtained during training with the OLT 107. In this way, the used bandwidth calculation unit 152 obtains the communication bandwidth of each ONU and calculates the total of the communication bandwidths of all the ONUs under its control. The calculated total communication band is a communication band of data to be transmitted to the upper communication apparatus 108.

  The bandwidth notification unit 153 notifies the higher-level communication device 108 of the total bandwidth information calculated by the used bandwidth calculation unit 152. The notification to the higher-level communication device 108 may be transmitted in a predetermined dedicated frame, or a dedicated protocol may be provided between the higher-level communication device 108. Further, the timing of notifying the band information may be performed by polling from the higher-level communication device 108, or may be periodically transmitted from the OLT 107. Alternatively, it may be transmitted to the OLT 107 at the start of communication or when there is a change in the ONU communication band.

  In this way, when a plurality of ONUs with different communication speeds are connected under the control, the OLT 107 obtains the communication bandwidth of each ONU from the uplink signal allocation time and communication speed of each ONU, and further communicates with each ONU. It is possible to calculate the used bandwidth necessary for communication with the higher-level communication device 108 by summing up the bands, and to notify the higher-level communication device of the calculated bandwidth information.

(Second Embodiment)
Next, a communication system 200 according to the second embodiment will be described with reference to FIG. In the first embodiment, the OLT 107 aggregates the used bandwidths of the subordinate ONUs and notifies the higher-level communication apparatus 108 of the used bandwidths. However, the communication system 200 according to the present embodiment aggregates a plurality of PON systems. The collective OLT 207 is used.

  In FIG. 4, the communication system 200 includes three PON systems, a collective OLT 207, and a host communication device 208. The three PON systems aggregated by the collective OLT 207 include a PON system 221 configured by a PON processing unit 209 that accommodates ONUs 201 and 202 having an uplink communication speed of 1 Gbps and an ONU 203 having 10 Gbps, and an uplink communication speed of 1 Gbps. The PON system 222 is configured by a PON processing unit 210 that accommodates an ONU 204 and a 10 Gbps ONU 205, and the PON system 223 is configured by a PON processing unit 211 that accommodates an ONU 206 having an uplink communication speed of 10 Gbps.

  The collective OLT 207 in FIG. 4 includes a PON processing unit 209, a PON processing unit 210, and a PON processing unit 211 that control three PON systems, an L2SW (L2 switch) 212 that performs level 2 routing, and three PON systems. A use band calculation unit 152a that calculates the band of the uplink signal and an output route determination unit 155a that determines an output route for transmitting the uplink signals of the three PON systems to the higher-level communication device 208 are configured.

  4, the PON processing unit 209, the PON processing unit 210, and the PON processing unit 211 include the functions of the WDM 161, the photoelectric signal conversion unit 162, and the SERDES unit 163 described in the OLT 107 in FIG. The function of the 164 uplink signal time allocation unit 151 is also included, and the transmission time is allocated to the subordinate ONU. Then, the PON processing unit 209, the PON processing unit 210, and the PON processing unit 211 output the bandwidth of the upstream signal of each subordinate ONU to the used bandwidth calculation unit 152a.

  The used bandwidth calculation unit 152a operates in the same manner as the used bandwidth calculation unit 152 of the first embodiment, and determines the bandwidth of the upstream signal of each ONU output from the PON processing unit 209, the PON processing unit 210, and the PON processing unit 211. The bandwidths of the upstream signals of the three PON systems are calculated together.

  The output route determination unit 155a operates in the same manner as the output route determination unit 155 of the first embodiment, and is based on the upstream signal bands of the three PON systems calculated by the use band calculation unit 152a. The output route to be transmitted to 208 is determined. Then, the L2SW 212 is instructed to distribute the upstream signals of the three PON systems to the determined output route.

  In FIG. 4, for example, the use band calculation unit 152 a has an upstream signal communication band of 3.6 Gbps for the PON system 221, an upstream signal communication band for the PON system 222 is 5.5 Gbps, and an upstream signal communication band for the PON system 223. 10 Gbps is calculated from the upstream signal bandwidth of each ONU output from the PON processing unit 209, PON processing unit 210, and PON processing unit 211 of the three PON systems, and is output to the output route determination unit 155a. Then, the output route determination unit 155a calculates a combination of three upstream signal bandwidths of 3.6 Gbps, 5.5 Gbps, and 10 Gbps, and effectively uses the 10 Gbps output route with the host communication device 208. Determine possible combinations. For example, the 10 Gbps upstream signal of the PON system 223 is assigned as it is to one 10 Gbps output route, and the 3.6 Gbps and 5.5 Gbps upstream signals of the PON systems 221 and 222 are time-division multiplexed to obtain a communication bandwidth of 9.1 Gbps. One output route of 10 Gbps is assigned as an upstream signal.

  In this way, even in the case of the communication system 200 having the collective OLT 207 that integrates a plurality of PON systems in which a plurality of communication speeds are mixed, the collective OLT 207 calculates the communication bandwidth of the upstream signal of each PON system, Since the optimum output route to be output to the higher-level communication device 208 is determined from the bandwidth information, the communication bandwidth of the higher-level network can be used effectively.

  Here, FIG. 5 shows a configuration of a communication system 200a as a practical example of the communication system 200 according to the present embodiment. In FIG. 5, the collective OLT 207 and the upper communication device 208 described in FIG. 4 are the same. In the collective OLT 207, two PON systems, a PON system 251 and a PON system 252, are integrated. The PON system 251 includes an ONU 241 corresponding to 10G-EPON, an ONU 242 corresponding to GE-PON, and an OLT 244 that accommodates the ONU 241 and the ONU 242 via an optical coupler 243. The PON system 252 includes an ONU 245 and an ONU 246 corresponding to GE-PON, and an OLT 248 that accommodates the ONU 245 and the ONU 246 via an optical coupler 247. Then, as described with reference to FIG. 4, the collective OLT 207 is connected to the higher-level communication device 208 corresponding to the aggregation switch by link aggregation. In link aggregation, for example, a plurality of transmission paths with a bandwidth of 1 Gbps can be regarded as one logical output route, and a redundant communication band is realized by changing the number of logically bundled transmission paths. be able to. As a result, when transmitting from the collective OLT 207 to the host communication device 208, it is possible to determine an output route according to the communication band of the PON system under the collective OLT 207. For example, in the above explanation, since the communication bandwidth of the output route to the upper level is a fixed bandwidth such as 10 Gbps or 100 Gbps, the output route is set so as to be as close to 10 Gbps as possible by combining the communication bandwidth of the subordinate OLT, for example. However, in the case of the link aggregation of FIG. 5, it becomes possible to adjust the communication bandwidth of the output route when transmitting from the collective OLT 207 to the upper communication device 208 to 5 Gbps, 8 Gbps, and the like. The communication band connected to the upper network can be used effectively.

(Third embodiment)
Next, a communication system 300 according to the third embodiment will be described with reference to FIG. In another embodiment, the OLT assigns the transmission time equally to the subordinate ONUs. However, in this embodiment, different transmission times are assigned according to the ONU communication speed. Note that the OLT 107a of the present embodiment is the same as the OLT 107 in the configuration of the OLT 107 of FIG. 2 of the first embodiment except for the operation of the uplink signal time allocation unit 151.

  In FIG. 6, the communication system 300 has the same configuration as the communication system 420 of FIG. 10 described in the prior art except that the OLT 107a is arranged instead of the OLT 418 and the upper communication apparatus 108 is arranged instead of the upper communication apparatus 419. is there. In the case of FIG. 10, the equal transmission time is allocated by the OLT 418 to the five ONUs 422 to ONU 426 regardless of the respective communication speeds. However, the uplink signal time allocation unit 151 of the OLT 107a of the present embodiment Different transmission times are assigned to each ONU according to the communication speed of each ONU. In FIG. 6, the ONU 422 to ONU 425 four ONU upstream signal transmission speed is 1 Gbps, and the ONU 426 upstream signal communication speed is 10 Gbps. Therefore, different transmission times are assigned to the ONU 422 to ONU 425 four ONUs and ONU 426. . As an example of the transmission time allocation method, the total communication speed of 4 Gbps for the four ONUs corresponds to 40% of the upper communication bandwidth of 10 Gbps. Therefore, the transmission time of 40% of the total transmission time is set to 4 units from ONU 422 to ONU 425. Assigned to the ONU. A transmission time of 10% is allocated to each ONU from the ONU 422 to the ONU 425, and the communication bandwidth of each ONU is 10 Mbps, which is 1/10 of the communication speed of 1 Gbps. On the other hand, since the ONU 426 uplink signal transmission rate is 10 Gbps, the remaining 60% of transmission time is allocated, and the ONU 426 communication band is 6/10 of 6/10 of the communication rate of 10 Gbps. As a result, the communication band output to the higher-level communication device 108 is 6.4 Gbps. In the case of the conventional communication system 420 shown in FIG. 10, the communication band output from the OLT 418 to the upper communication device 419 is 2.8 Gbps, whereas in the case of the present embodiment shown in FIG. The communication band usage efficiency can be increased about 2.3 times.

  Further, in the communication system 300 according to the present embodiment, the OLT 107a obtains the communication bandwidth of each subordinate ONU and notifies the upstream communication device 108 of the upstream communication bandwidth, similarly to the communication system 100 described in the first embodiment. Since the higher-level communication apparatus 108 determines the output route to be transmitted to the higher-level network from the band information notified from the OLT 107a, the communication band can be used more effectively.

(Fourth embodiment)
Next, a communication system 350 according to the fourth embodiment will be described with reference to FIG. The present embodiment is an application example to the communication system 350 in which the PON system is arranged in two stages. For example, in the communication system 350, a conventional 1 Gbps PON system 360 having a low communication speed can be incorporated into a high-speed 10 Gbps PON system 361. In FIG. 7, the OLT 107 and the higher-level communication device 108 having the same reference numerals as those in FIG. 1 are the same.

  In FIG. 7, ONUs 351 and 352 constituting a Gbps GE-PON PON system 360 are accommodated in an OLT 354 that is a feature of this embodiment via an optical coupler 353. Here, the OLT 354 includes an OLT 355 that accommodates the ONUs 351 and 352 that constitute the 1 Gbps PON system 360, and an ONU 356 that constitutes one ONU of the 10 Gbps PON system 361. Therefore, the OLT 354 operates as one ONU when viewed from the upper side, and operates as one OLT when viewed from the lower side.

  On the other hand, in the Gbps PON system 361, in addition to the ONU 356 included in the OLT 356, an ONU 357, an ONU 358, and an ONU 359 are accommodated in the OLT 107 via the optical coupler 360. The OLT 107 is connected to the host communication device 108 as in FIG. Therefore, the operation between the OLT 107 and the upper communication apparatus 108 is performed in the same manner as in the first embodiment. The OLT 107 obtains the communication band of each ONU under its control and notifies the upper communication apparatus 108 of the upstream communication band. Since the communication device 108 determines the output route to be transmitted to the upper network from the band information notified from the OLT 107, the higher communication band can be used effectively.

  As described above, the communication system 350 according to the present embodiment can incorporate the conventional 1 Gbps PON system 360 having a low communication speed into the high-speed 10 Gbps PON system 361 and can effectively use a communication band for connecting to a higher-level network. Can be used.

  As described above, in each embodiment, the communication system, the station-side device, the higher-level communication device, and the bandwidth control method according to the present invention are OLT even in the case of a communication system having a PON system in which a plurality of communication speeds are mixed. Since the bandwidth information is transmitted from the network to the higher level communication device and the output route to the higher level network is controlled, the communication bandwidth in the higher level network can be used more effectively than the OLT. As a result, since the current optical fiber network can be used efficiently, the addition of new optical fiber cables can be suppressed as much as possible, and the cost of the communication system can be reduced. In particular, it is possible to minimize the establishment of a new high-speed network in the network higher than the OLT.

100, 200, 200a, 300, 350, 410, 420 ... communication system 101, 221-223, 251, 252, 360, 361, 401, 411, 421 ... PON systems 102-105, 201-206, 241 to 246, 351, 352, 356 to 359, 402 to 404, 412 to 416, 422 to 426 ... ONU
107,107a, 127,137,207,307,244,248,354,355,406,418 ... OLT
106, 243, 247, 353, 360, 405, 417... Optical coupler 108, 208, 419... Upper communication device 151... Uplink signal time allocation unit 152, 152 a. ..Band information notifying unit 154... Band information receiving unit 155, 155a... Output route determining unit 161... WDM unit 162 .. Photoelectric signal converting unit 163 .. SERDES unit 164, 209- 211 ... PON processing unit 165 ... upper network IF
166 ... Control system 167 ... Power supply unit 207 ... Collective OLT
212 ... L2SW

Claims (7)

A communication system comprising a higher-level communication device connected to a higher-level network, a plurality of station-side devices connected to the higher-level communication device, and a plurality of subscriber-side devices accommodated in the station-side device. In a communication system constituting a PON system in which a plurality of communication speeds are mixed between the station side device and the plurality of subscriber side devices,
The station side device
A PON interface connecting the plurality of subscriber side devices;
A host network interface connected to the host communication device;
An uplink signal time allocation unit that allocates a data transmission time for transmitting data from the plurality of subscriber side devices to the station side device;
The upper-layer communication is obtained from the allocated time of the upstream signal time allocation unit and the communication speed of each subscriber-side device for each upstream use band in the PON section communicating with each subscriber-side device via the PON interface. A used bandwidth calculating unit that calculates a total used bandwidth required for communication with the device;
A bandwidth information notification unit that notifies the host communication device of the use band information obtained by the use band calculation unit via the host network interface;
The upper communication device is:
A band information receiving unit for receiving the used band information respectively notified from the band notification unit of the plurality of station side devices;
An output route determining unit for determining an output route when transmitting to the upper network from the used band information of the plurality of station side devices received by the band information receiving unit. . The communication system according to claim 1,
The output route determining unit, based on the used bandwidth information, determines the upstream communication bandwidth of the plurality of station side devices so that the use ratio of the communication bandwidth of the output route to the upper network is maximized. A communication system characterized by determining a combination. A communication system comprising a higher-level communication device connected to a higher-level network, a plurality of station-side devices connected to the higher-level communication device, and a plurality of subscriber-side devices accommodated in the station-side device. In the station side device of the communication system constituting the PON system in which a plurality of communication speeds are mixed between the station side device and the plurality of subscriber side devices,
A PON interface connecting the plurality of subscriber side devices;
A host network interface connected to the host communication device;
An uplink signal time allocation unit that allocates a data transmission time for transmitting data from the plurality of subscriber side devices to the station side device;
The upper-layer communication is obtained from the allocated time of the upstream signal time allocation unit and the communication speed of each subscriber-side device for each upstream use band in the PON section communicating with each subscriber-side device via the PON interface. A used bandwidth calculating unit that calculates a total used bandwidth required for communication with the device;
A station-side apparatus of a communication system, comprising: a band information notification unit that notifies the host communication device of the use band information obtained by the use band calculation unit via the host network interface. A communication system comprising a higher-level communication device connected to a higher-level network, a plurality of station-side devices connected to the higher-level communication device, and a plurality of subscriber-side devices accommodated in the station-side device. In the host communication device of the communication system constituting the PON system in which a plurality of communication speeds are mixed between the station side device and the plurality of subscriber side devices,
A band information receiving unit for receiving the used band information respectively notified from the band notification unit of the plurality of station side devices;
An output route determining unit that determines an output route when transmitting to the upper network from the used band information of the plurality of station side devices received by the band information receiving unit. Host communication device. The upper communication apparatus of the communication system according to claim 4,
The output route determining unit, based on the used bandwidth information, determines the upstream communication bandwidth of the plurality of station side devices so that the use ratio of the communication bandwidth of the output route to the upper network is maximized. A higher-level communication device of a communication system, characterized by determining a combination. Used in a communication system including a higher-level communication device connected to a higher-level network, a plurality of station-side devices connected to the higher-level communication device, and a plurality of subscriber-side devices accommodated in the station-side device. In the bandwidth control method of a communication system constituting a PON (Passive Optical Network) system in which a plurality of communication speeds are mixed between the station side device and the plurality of subscriber side devices,
In the station side device,
An uplink signal time assignment procedure for assigning a data transmission time for transmitting data from the plurality of subscriber side devices to the station side device;
The allocated time allocated in the uplink signal time allocation procedure for each use band in the upstream direction of the PON section communicating with each subscriber side device via the PON interface connecting the plurality of subscriber side devices, and each subscriber Obtained from the communication speed of the side device, a used bandwidth calculation procedure for calculating the total used bandwidth necessary for communication with the host communication device,
A bandwidth information notification procedure for notifying the higher-order communication device of the used bandwidth information obtained in the used bandwidth calculation procedure via a higher-level network interface connected to the higher-order communication device;
In the upper communication device,
Band information reception procedure for receiving the used band information respectively notified from the band notification unit of the plurality of station side devices;
An output route determining procedure for determining an output route when transmitting to the higher-order network from the used bandwidth information of the plurality of station side devices received in the bandwidth information receiving procedure. Bandwidth control method. In the communication system band control method according to claim 6,
In the output route determination procedure, based on the use band information, the uplink communication band of the plurality of station side devices is set so that the use ratio of the communication band of the output route to the upper network is maximized. A bandwidth control method for a communication system, characterized by determining a combination.

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