JP2004357237A - Device, system, and method for communication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device, a system, and a method for communication capable of improving a communication efficiency by monitoring the state of the communication availability of each device when a plurality of devices conduct a time devision multiplex accessing type communication. <P>SOLUTION: The communication system is composed of an ONU on a subscriber side and an OLT on a communication common carrier side, and the CPU 15 of the OLT comprises an upload-permit message transmitting means 15a, a state monitoring message transmitting means 15b for monitoring the communication state of the ONU, a data transmission request receiving means 15c for receiving a data transmission request, a state-notification receiving means 15d for receiving the state notification, a band calculating means 15e for calculating a band which the communicating ONU uses, and a band allocating means 15f or the like for allocating the band. The CPU 15 timely loads these modules and calculates to make each function perform. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a communication system of a communication system in which a plurality of devices perform time-division multiple access communication, and more particularly, to a communication device for improving communication efficiency by monitoring a communicable state of each device. The present invention relates to a system and a communication method.
[0002]
[Prior art]
In order for a plurality of devices to communicate with each other by sharing a single communication medium, it is necessary that a signal transmitted by one device can be distinguished from a signal transmitted by another and can be read. This system is generally called a multiple access system, and one of them is a time division multiple access system.
[0003]
The time division multiple access method is a method that enables discrimination by changing the transmission time of each device. In the time division multiple access system, the number of devices that transmit a signal to a communication medium at a certain time is always one or less, and control is performed so that signal collision does not occur. Therefore, a device that receives a signal from the communication medium can read all data from other devices.
[0004]
The time division multiple access system is roughly classified into two types: a system in which all devices control multiple access by the same procedure, and a system in which a certain device integrally controls multiple access. Here, the former is defined as an “autonomous type” time division multiple access system, and the latter is defined as a “centralized control type” time division multiple access system. Examples of the “autonomous” time division multiple access method include Ethernet (registered trademark) and token ring. Examples of the “centralized control type” time division multiple access system include an SCM-PDS (subcarrier multiplex-passive double star) system and an ATM-PDS (asynchronous transfer mode-passive double star) system.
[0005]
The SCM-PDS system and the ATM-PDS system are used as a communication system connecting a communication or broadcasting company and its subscribers via an FTTH (fiber to the home) type communication medium. In the SCM-PDS system and the ATM-PDS system, the communication system is composed of an optical line terminal (OLT: optical line terminal; hereinafter, referred to as "OLT") and an optical network unit (ONU: optical network). Unit, hereinafter referred to as "ONU").
[0006]
At this time, “one-to-many” communication with a plurality of ONUs is performed with respect to the OLT. The OLT and the ONU are interconnected by a downstream communication medium and an upstream communication medium. The signal transmitted by the OLT reaches all ONUs via the downstream communication medium. Signals transmitted by all ONUs reach the OLT via the upstream communication medium, and a "centralized control type" time division multiple access system is used as the upstream communication system.
[0007]
In the SCM-PDS system and the ATM-PDS system, the OLT is responsible for centralized control of time division multiple access. As a basic procedure, (1) the OLT transmits a signal for permitting the specific ONU to transmit upstream via the downstream communication medium. In this signal, a period during which the ONU can transmit an uplink signal is specified. (2) The ONU that has received the notification of the permission of the upstream transmission can transmit the upstream signal to the upstream communication medium within the specified transmission period.
[0008]
In this optical transmission system, various existing systems are used for controlling access when a device at the communication business office and a plurality of devices at the customer premises perform bidirectional communication (for example, see Patent Document 1). Exists.
[0009]
[Patent Document 1]
JP-A-10-247888
[0010]
[Problems to be solved by the invention]
The transmission period in uplink communication is fixed and its band is allocated. Considering a case where n ONUs are connected to an OLT, a transmission period t is given to all ONUs, and a transmission opportunity is given when a transmission opportunity is given to n ONUs once. Is a total transmission period of t × n (see FIG. 4).
[0011]
However, the uplink traffic of the ONUs during a certain period is not equal. At this time, if the transmission periods are equally given to the n ONUs, the ONUs cannot perform uplink communication exceeding the transmission period t. In other words, even if there is another ONU that has performed communication only for a period shorter than the given transmission period t, and there is a surplus in the communication amount of the band used in the uplink communication medium, the transmission period t The subscriber who wants to use it could not use the bandwidth of another ONU.
[0012]
As described above, in the conventional time division multiple access method, even though the uplink traffic of the ONU group is not always constant, the transmission period is equally given to the ONU group and the efficiency of the entire uplink communication is reduced. .
[0013]
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and when a plurality of devices perform time-division multiple access type communication, improve the communication efficiency by monitoring the communicable status of each device. A communication device, a communication system and a communication method.
[0014]
[Means for Solving the Problems]
In view of the above problems, a first feature of the present invention is (a) a communication device that performs communication with a plurality of other communication devices via a network, and performs communication with the plurality of other communication devices. And (b) receiving a data transmission request including a code capable of identifying the desired communication device from the desired communication device having received the permission message. (D) status monitoring message transmitting means for transmitting a status monitoring message for monitoring the communication status to another communication device that does not want to communicate and has not received the data transmission request; Status notification receiving means for receiving a status notification message for receiving a permission message from another communication device which does not want to receive the status monitoring message, and A bandwidth allocation storage device that stores the number of other communication devices that desire communication and the number of other communication devices that do not want communication updated each time a transmission request is received and a status notification message is received; and (f) another communication device that desires communication. Bandwidth calculating means for calculating the bandwidth used for communication by another communication device that desires each communication based on the relationship between the detected number and the bandwidth of the network; The gist of the present invention is that the communication device includes a band allocating unit that allocates all bands used for communication based on a code that can identify another communication device. Further, the first feature of the present invention is that (h) the entire band includes a band for transmitting an authorization message and a data transmission request with another communication device that desires communication, and another band that does not desire communication. And a band for causing at least one of a permission message, a status monitoring message, and a state notification message to be communicated between the communication device and the (i) band allocating means. Is allocated to at least one of the other communication devices not wishing to communicate, and a band for transmitting at least one of the permission message, the status monitoring message, and the status notification message is allocated to at least one of the other communication devices not wishing to communicate. ) The permission message includes a receivable period of the data transmission request, and the data transmission request receiving means receives the data during the receivable period. And it may include receiving a data transmission request only.
[0015]
A second feature of the present invention is (a) a communication device for requesting another communication device to transmit data via a network, and receiving a permission message for permitting communication from the other communication device. Means for transmitting a data transmission request for requesting data transmission including a code capable of identifying the own communication apparatus to another communication apparatus when (b) communication permission is desired; If the data transmission request has not been transmitted, a status monitoring message receiving means for receiving a status monitoring message for asking for a communication status from another communication device, and (d) receiving the status monitoring message and wishing to receive a permission message. In this case, the gist is that the communication device includes a status notification message transmitting unit that transmits a status notification message to another communication device.
[0016]
A third feature of the present invention is (a) a system including a communication device for performing communication via a network and a request communication device for requesting data transmission, and a permission for permitting communication to a plurality of request communication devices. Permission message transmitting means for transmitting a message, data transmission request receiving means for receiving a data transmission request including a code capable of identifying a requesting communication device desiring communication, and monitoring a communication state of a requesting communication device not desiring communication. A status monitoring message transmitting unit that transmits a message, a status notification receiving unit that receives a status notification message that desires to receive a permission message from a requesting communication device that does not desire communication, and is updated every time a data transmission request is received and a status notification message is received. Bandwidth allocation record that stores the number of requesting communication devices that wish to communicate and the number of requesting communication devices that do not want communication Device, a band calculating means for detecting the number of requesting communication devices desiring communication and calculating a band used for communication by the requesting communication device desiring each communication based on a relationship between the detected number and a band of the network, a band, and a communication A communication device having a band allocating means for allocating the entire band used for communication based on a code capable of identifying the requesting communication device desiring the request, and (b) receiving a permission message for permitting the communication from the communication device. Permission message receiving means, when requesting communication permission, data transmission request transmitting means for transmitting a data transmission request for requesting data transmission including a code capable of identifying the communication apparatus to the communication apparatus, and not transmitting the data transmission request Status monitoring message receiving means for receiving a status monitoring message from the communication device asking about the communication status, receiving and permitting the status monitoring message And summarized in that a communication system comprising a request communication device and a status notification message transmitting means for transmitting a status notification message to the communication device if you wish to receive the message.
[0017]
A fourth feature of the present invention is that (a) a step of transmitting a permission message for permitting communication to a plurality of other communication devices via a network, and (b) another communication that desires communication receiving the permission message. Receiving, from the device, a data transmission request including a code capable of identifying the other communication device with which communication is desired; and (c) transmitting a communication state to the other communication device which does not want to communicate without receiving the data transmission request. Transmitting a status monitoring message to be monitored, (d) receiving a status notification message that desires to receive a permission message from another communication device that does not want to communicate receiving the status monitoring message, and (e) data transmission Each time a request is received and every time a status notification message is received, the number of other communication devices that desire communication and the number of other communication devices that do not want communication are allocated and stored. And (f) detecting the number of other communication devices that desire communication and detecting the number of other communication devices desired for communication based on the relationship between the detected number and the bandwidth of the network. And g., And (g) allocating all bands used for communication based on a band and a code capable of identifying another communication device that desires communication. .
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
(Overview of communication system)
First, an outline of a communication system according to an embodiment of the present invention will be described with reference to FIG. The following description will be made on the assumption that an Internet connection access method using a PON (Passive Optical Network) is used as an example of a particularly effective communication method.
[0019]
The PON uses an optical fiber cable 1 as a network. Generally, the optical fiber cable 1 is branched radially. Time-division multiple access is suitable for realizing communication from a carrier station to a plurality of service subscribers using this network. The communication business bureau includes the OLT 10 as a communication device, and the subscriber premises includes ONUs 20a, 20b, 20c,...
[0020]
The OLT 10 is installed in a service provider facility such as a switching center of a telephone company, which is a telecommunications carrier, or a relay station (head end) of a cable television company. On the other hand, the ONUs 20a, 20b, 20c,... Are installed in a distributed hub having a fiber-to-the-curve configuration arranged near houses, condominiums, and office buildings. The communication signal propagates between the OLT 10 and the ONUs 20a, 20b, 20c... Via the optical fiber cable 1, and at this time, communication from one OLT 10 to 32 fixed ONUs is possible. For this reason, it is relatively easy to monitor the status of each subscriber's LAN 5a, 5b, 5c.
[0021]
... Up to 100 Mbps using the wavelength of 1.3 μm for upstream communication from the ONUs 20 a, 20 b, 20 c to the OLT 10, and 1.49 μm for downstream communication from the OLT 10 to the ONUs 20 a, 20 b, 20 c. To In addition, it is also possible to superimpose a cable television broadcast on a wavelength such as 1.55 μm.
[0022]
In the communication system according to the embodiment of the present invention, as shown in FIG. 1, an OLT 10, an optical splitter 2, an exchange 3, a distribution server 4, and the like are arranged on the communication business office side, and an ONU 20a is installed on the subscriber home side. 20b, 20c... And home devices such as personal computers, telephones, and videos connected thereto.
[0023]
The OLT 10 converts a signal flowing through the optical fiber cable 1 so that it can be used in its own device. The exchange 3 establishes a telephone connection between internal extensions and a public line. Specifically, it refers to PBX (private branch exchange) and the like. The distribution server 4 is a server that searches for information such as a moving image such as a video, a still image such as a photo, and text data such as a character requested by the subscriber, and distributes the information to the requesting subscriber. The optical splitter 2 joins an optical signal to be transmitted to the subscriber network with an optical signal of a communication system, branches the optical signal, and transmits the optical signal to the ONUs 20a, 20b, 20c,.
[0024]
In the ONUs 20a, 20b, 20c,..., The optical signals are terminated and converted into electric signals. After that, the electric signals are output from the ONUs 20a, 20b, 20c... Via the LANs 5a, 5b, 5c to personal computers, telephones, videos, etc. of the subscribers' homes, and are input into the respective devices through STBs (set-top boxes).
[0025]
The OLT 10 according to the embodiment of the present invention monitors the communication state with each ONU when transmitting the information requested by the subscriber by the optical signal as described above, and performs the reallocation of the band based on the monitoring result. Do. For example, three ONUs 20a, 20b, and 20c communicated in a certain cycle, but in the next cycle, communication from the ONU 20c was interrupted and two ONUs 20a and 20b were communicating. Detected. At this time, the OLT 10 reallocates the entire band used for transmitting the optical signal, and makes the surplus band of the ONU 20c not performing communication available to the ONUs 20a and 20b performing communication. As a result, the surplus bandwidth can be used effectively. The details of the device relating to the communication system will be described below.
[0026]
(Optical subscriber line terminal equipment)
As shown in FIG. 2, an OLT 10 according to an embodiment of the present invention includes an input device 11, an output device 12, a wavelength division multiplexing unit 15g, a communication control device 13, a main storage device 14, and a processing control device (CPU) 15. , A subscriber information storage device 16, a bandwidth allocation storage device 17, a program storage device 18, and the like. The CPU 15 includes an upstream permission message transmitting unit 15a, a state monitoring message transmitting unit 15b, a data transmission request receiving unit 15c, a state notification receiving unit 15d, a band calculating unit 15e, a band allocating unit 15f, and the like.
[0027]
The subscriber information storage device 16 stores the type of service to which the subscriber subscribes, the addresses, names, addresses, etc. of the ONUs 20a, 20b, 20c. Further, IP addresses of personal computers, telephones, videos and the like connected to the home LANs 5a, 5b and 5c may be stored. The band allocation storage device 17 is a device that currently communicates among the 32 ONUs that use the band, the total number of devices, and the frequency with which each ONU 20a, 20b, 20c. The time zone to be used is stored. The program storage device 18 stores a program for performing arithmetic processing by the CPU 15.
[0028]
The upstream permission message transmitting unit 15a is a permission message transmitting unit, and is a module that transmits a message for permitting the ONUs 20a, 20b, 20c,... To start upstream communication. This message includes codes such as addresses for all ONUs 20a, 20b, 20c... And a period during which uplink transmission is possible. The status monitoring message transmitting means 15b is a module for transmitting a message for monitoring the status to the ONUs 20a, 20b, 20c.
[0029]
The data transmission request receiving unit 15c is a module that receives a data transmission request transmitted from the ONUs 20a, 20b, 20c,. The data transmission request receiving means 15c receives not only the data transmission request but also other uplink transmission data transmitted from the ONUs 20a, 20b, 20c. The status notification receiving unit 15d is a module that receives a status notification message transmitted from the ONUs 20a, 20b, 20c,... The band calculating unit 15e detects the number of ONUs 20a, 20b, 20c... Requesting data transmission from the OLT 10 via optical fiber communication, and one ONU can be used according to the relationship between the number and the band. This is a module for calculating a bandwidth frame. The bandwidth allocating unit 15f is a module that allocates a bandwidth according to a bandwidth frame that can be used by one ONU.
[0030]
The wavelength division multiplexing means 15g is a means for realizing a wideband optical network using a so-called WDM (wavelength division multiplex) transmission technique. More specifically, the wavelength division multiplexing unit 15g includes a transmission electric circuit (not shown), a light emitting element, an optical multiplexer, an optical demultiplexer, a light receiving element, a light receiving electric circuit, and the like. At the time of transmission, optical signals from light sources having different wavelengths are coupled to one optical fiber cable 1 by an optical multiplexer. At the time of reception, an optical signal from the optical fiber cable 1 is used to split each wavelength by an optical demultiplexer, which is converted into an electric signal by a light receiving element. The wavelength division multiplexing means 15g multiplexes channels through light of different wavelengths through one optical fiber cable 1, and transmits large-capacity data in two directions. Further, by increasing the number of wavelengths or narrowing the channel interval, data transmission with a larger capacity can be performed.
[0031]
The input device 11 is an interface for receiving an input signal from the customer premises equipment. The output device 12 is an interface that transmits an output signal to the customer premises equipment. The communication control device 13 generates a control signal for transmitting and receiving data via a wireless or wired network and the optical fiber cable 1. The main storage device 14 temporarily stores a program describing a processing procedure and data to be processed, and delivers machine instructions and data of the program according to a request from the CPU 15. The data processed by the CPU 15 is written to the main storage device 14. The main storage device 14 and the CPU 15 are connected by an address bus, a data bus, control signals, and the like.
[0032]
(Optical subscriber line termination equipment)
The ONUs 20a, 20b, 20c... According to the embodiment of the present invention include an input device 21, an output device 22, a wavelength division multiplexing unit 25e, a communication control device 23, a main storage device 24, The apparatus includes a device (CPU) 25, a transmission data storage device 26, a program storage device 27, and the like. The CPU 25 includes an upstream permission message receiving unit 25a, a state monitoring message receiving unit 25b, a data transmission request transmitting unit 25c, a state notification message transmitting unit 25d, and the like.
[0033]
The transmission data storage device 26 is a buffer for temporarily storing transmission data such as a data transmission request from the ONUs 20a, 20b, 20c. The program storage device 27 stores a program for the CPU 25 to perform arithmetic processing.
[0034]
The upstream permission message receiving unit 25a is a permission message receiving unit, and is a module that receives the upstream permission message from the OLT 10. The status monitoring message receiving unit 25b is a module that receives a status monitoring message from the OLT 10.
[0035]
The data transmission request transmission unit 25c is a module that transmits to the OLT 10 uplink transmission data representing the data transmission request and codes such as respective addresses for identifying the ONUs 20a, 20b, 20c. The status notification message transmitting unit 25d is a module that transmits to the OLT 10 a status notification message including a code such as an address for identifying each of the ONUs 20a, 20b, 20c. The wavelength division multiplexing means 25e is the same as the wavelength division multiplexing means 15g, and thus the description is omitted.
[0036]
(Communication method using optical subscriber line terminal equipment)
Hereinafter, the operation of the OLT 10 at the time of the first communication will be described with reference to the flowchart of FIG.
[0037]
(A) First, in step S101, the uplink permission message transmitting means 15a in FIG. 2 inquires of the ONUs 20a, 20b, 20c,. The upstream permission message transmitting unit 15a transmits an upstream permission message including a period during which upstream transmission is possible via the optical fiber cable 1 by the wavelength division multiplexing unit 15g.
[0038]
(B) In step S102, the data transmission request receiving means 15c in FIG. 2 receives uplink transmission data such as a data transmission request from only the ONUs 20a, 20b,... In step S103, the bandwidth calculating unit 15c counts the number of uplink transmission data such as the received data transmission request, and calculates the bandwidth to be allocated to one communicating ONU 20a, 20b,... Based on the counted number and the ratio of the total bandwidth. . In step S104, the bandwidth allocating unit 15f allocates the use of the entire bandwidth based on the calculation result. For example, when the entire bandwidth of 320 Mbps is used by 32 communicating ONUs 20a, 20b... As in the related art, 10 Mbps is allocated as a bandwidth usable by each communicating ONU 20a, 20b. When the entire bandwidth 320 Mbps is used by ten communicating ONUs 20a, 20b,..., 32 Mbps is allocated as a bandwidth usable by each communicating ONU 20a, 20b,. At this time, the non-communicating ONUs 20c... Which have not been counted, the count thereof (the value obtained by subtracting the count number from 32), the data transmission request, and the like are stored in the bandwidth allocation storage device 17. The data transmission request and the like include the address of the requesting ONU.
[0039]
(C) Finally, in step S105, the wavelength division multiplexing means 15g transmits the requested data to the addresses of the communicating ONUs 20a, 20b.
[0040]
Next, the operation of the OLT 10 at the time of communication after the initial communication will be described using the flowchart of FIG. In the following description, assuming that the count number at the time of receiving the previous data communication request is 20 and the number not counted is 12, the inquiry about the communication state will be described.
[0041]
(A) First, in step S201, the upstream permission message transmitting unit 15a of FIG. 2 transmits the wavelength division multiplexing unit to the previously counted ONUs of the subscriber's home, that is, the addresses of the 20 ONUs 20a, 20b,. 15g, via the optical fiber cable 1, transmits an uplink permission message including a period during which uplink transmission is possible. For example, as shown in FIG. 5, a 15 Mbps band (hereinafter, referred to as "main sequence band") is allocated to all the communicating ONUs 20a, 20b, and transmitted. When transmitting the requested data to the addresses of the communicating ONUs 20a, 20b, etc., for which the data transmission has been requested, it is preferable that the upstream permission message means transmit the requested data simultaneously as a part of the data. .
[0042]
(B) Further, in step S202, the status monitoring message transmitting means 15b sends the ONU of the subscriber's home which was not counted last time, that is, one of the 12 non-communication ONUs 20c. Send a status monitoring message. For example, as shown in FIG. 5, a bandwidth of 20 Mbps (hereinafter, referred to as “test sequence bandwidth”) is allocated to one non-communication ONU 20c and transmitted.
[0043]
(C) In step S203, the data transmission request receiving unit 15c transmits data only from the ONUs 20a, 20b,... Of the last communication ONUs 20a, 20b,. Receive requests and so on. In step S204, when the status notification receiving unit 15d receives a status notification message from one of the non-communication ONUs 20a, 20b,... During a period in which uplink transmission is possible, it determines that this ONU has changed from the non-communication state to the communication state. If the status notification message is not received during the period in which the uplink transmission is possible, it is determined that the communication state is still non-communication. This determination result is stored in the bandwidth allocation storage device 17.
[0044]
(D) In step S205, the bandwidth calculating unit 15e counts the number of received data transmission requests and the number of status notification messages notified, and calculates one communication ONU 20a, 20b,. Calculate the main sequence band and the test sequence band to be assigned to. It is preferable that the test sequence band is fixed. In step S206, the bandwidth allocating unit 15f reallocates the used bandwidth of the entire bandwidth based on the calculation result. At this time, the count number, the ratio to the total band, and the like are stored in the band allocation storage device 17.
[0045]
(C) Finally, in step S207, the wavelength division multiplexing means 15g transmits the requested data to the communicating ONUs 20a, 20b,. Thereafter, the same operation is repeated from step S201.
[0046]
(Communication method using optical network unit)
Next, the operation of the ONUs 20a, 20b, 20c... At the time of initial communication will be described with reference to the flowchart of FIG.
[0047]
(A) First, in step S301, the uplink permission message receiving means 25a (see FIG. 3) of the communicating ONUs 20a, 20b,... (See FIG. 3) inquires of a communication state including a period during which uplink transmission is possible via the optical fiber cable 1. Receive an uplink permission message for The non-communicating ONUs 20c do not receive this uplink permission message or do not respond to it even if they are received.
[0048]
(B) In step S302, the data transmission request transmitting means 25c of the communicating ONUs 20a, 20b,... Creates uplink transmission data such as a data transmission request and transmits it to the OLT 10 within a period in which uplink transmission is possible (step S302). S303).
[0049]
Next, the operation when the non-communication ONUs 20c start communication will be described with reference to the flowchart of FIG.
[0050]
(A) First, in step S401, the non-communication ONUs 20c start communication by turning on power, starting network connection, and the like. In step S402, after waiting for a while, the status monitoring message receiving means 25b receives, via the optical fiber cable 1, a status monitoring message for monitoring the communication status addressed to the own device (ONU).
[0051]
The ONU 20c may request a state monitoring message from the OLT 10 when starting communication. The waiting transmission data is temporarily stored in the transmission data storage device 26. The OLT 10 may transmit a status monitoring message by detecting whether or not there is data in the transmission data storage device 26.
[0052]
(B) In step S403, the status notification message transmitting unit 25d of the ONU 20c waiting for communication creates a status notification message and transmits it to the OLT 10 (step S404). Thereafter, the process returns to step S301, and the ONU 20c waiting for communication starts normal communication.
[0053]
According to the above description, when a signal addressed to itself is received from the OLT and the ONU performs uplink transmission, the OLT monitors the ONU to notify the OLT of a data communication state. With this ingenuity, the OLT detects that some of the communicating ONUs that are currently using the main sequence band are no longer in a data transmittable state, and that the non-communicating ONUs that have been monitored using the test sequence band It is possible to detect that the ONU has changed to the data transmission enabled state. After this detection, the OLT changes the combination of the main sequence band and the test sequence band to be allocated to the entire band as necessary. This allows the ONU during communication to use the surplus bandwidth of the ONU during non-communication which has been generated when the communication is performed with the band fixed as in the related art, so that efficient communication using the entire band uniformly can be performed. It becomes possible.
[0054]
In the embodiment of the present invention, for convenience, the arrangement relation of “OLT on the communication business office side” and “ONU on the subscriber home side” is used, but there are no restrictions on the physical form and the installation position. These may be one functional part of a physical device. These devices may be physically a single device.
[0055]
Further, in the embodiment of the present invention, the OLT and the ONU are used for the terminating device in order to use the optical fiber technology. However, the present invention is not limited to this embodiment, and any one of the Internet, the intranet, the LAN, etc. Of course, it can be applied to a communication network cable. In this case, a terminal device such as a DTE (Data Terminal Equipment) or a DCE (Data Circuit Terminating Equipment) may be used.
[0056]
In detecting the communication connection state of the ONU in step S202, it is possible to easily check whether or not an interface such as a LAN is connected to an opposing device. For example, when it can be checked that the communication port of the ONU is not connected to another device, it can be clearly determined that the ONU is not in a state in which uplink data can be transmitted. The ONU is a time division multiple access communication device, which may be realized by a modem or the like.
[0057]
【The invention's effect】
According to the present invention, it is possible to provide a communication device, a communication system, and a communication method that can improve communication efficiency by monitoring a communicable state of each device when a plurality of devices perform time division multiple access communication. Can be.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a communication system using a communication device according to an embodiment of the present invention.
FIG. 2 is an internal configuration diagram of the communication device according to the embodiment of the present invention.
FIG. 3 is an internal configuration diagram of the communication device according to the embodiment of the present invention.
FIG. 4 is a configuration diagram illustrating a configuration of a band.
FIG. 5 is a configuration diagram illustrating a configuration of a band.
FIG. 6 is a flowchart showing an operation of the communication device at the first time.
FIG. 7 is a flowchart showing the operation of the communication device after the first time.
FIG. 8 is a flowchart showing an operation of the communication device at the first time.
FIG. 9 is a flowchart showing the operation of the communication device after the first time.
[Explanation of symbols]
1: Optical fiber cable
2. Optical splitter
3. Exchange
4: Distribution server
5a, 5b, 5c ... LAN
10 OLT
11 Input device
12 Output device
13. Communication control device
14: Main storage device
15 ... CPU
15a: permission message transmission means
15b ... Status monitoring message transmission means
15c: Data transmission request receiving means
15d ... status notification receiving means
15e bandwidth calculating means
15f band allocation means
15g: wavelength division multiplexing means
16 ... subscriber information storage device
17 ... Band allocation storage device
18 Program storage device
20a, 20b, 20c ... ONU
21 Input device
22 Output device
23 Communication control device
24: Main storage device
25 ... CPU
25a: permission message receiving means
25b ... Status monitoring message receiving means
25c: Data transmission request transmission means
25d: Status notification message transmitting means
25e: wavelength division multiplexing means
26: Transmission data storage device
27 Program storage device

Claims (7)

A communication device that communicates with a plurality of other communication devices via a network,
Permission message transmitting means for transmitting a permission message permitting communication to the plurality of other communication devices,
From another communication device that desires communication receiving the permission message, a data transmission request receiving unit that receives a data transmission request that includes a code capable of identifying the other communication device that desires the communication,
A status monitoring message transmitting unit that transmits a status monitoring message for monitoring a communication status to another communication device that does not desire the communication that did not receive the data transmission request,
A status notification receiving unit that receives a status notification message that desires to receive the permission message, from another communication device that does not want to communicate that has received the status monitoring message,
A bandwidth allocation storage device storing the number of other communication devices that desire the communication and the number of other communication devices that do not want the communication updated each time the data transmission request is received and the status notification message is received,
A band calculating unit that detects the number of the other communication devices that desire the communication, and calculates a band that the other communication device that wants the communication uses for communication by the relationship between the detected number and the band of the network; ,
A communication device comprising: a band allocating unit configured to allocate all bands used for communication based on the band and a code capable of identifying another communication device that desires the communication. The entire band is a band for communicating the permission message and the data transmission request with another communication device that desires the communication, and the permission message between another communication device that does not want the communication, The communication device according to claim 1, further comprising a band for communicating at least one of a status monitoring message and the status notification message. The band allocating means allocates a band for communicating the permission message and the data transmission request to all the other communication devices that desire the communication, and at least one of the permission message, the state monitoring message, and the state notification message. The communication device according to claim 1, wherein a band for communicating one of the communication devices is assigned to at least one of the other communication devices that do not desire the communication. The method according to claim 1, wherein the permission message includes a receivable period of the data transmission request, and the data transmission request receiving unit receives only the data transmission request received during the receivable period. Communication device according to claim. A communication device for requesting data transmission to another communication device via a network,
Permission message receiving means for receiving a permission message permitting communication from the other communication device,
If the communication permission is desired, a data transmission request transmitting unit that transmits a data transmission request for requesting the data transmission including a code capable of identifying the own communication device to the other communication device,
If the data transmission request has not been transmitted, a status monitoring message receiving unit that receives a status monitoring message that is queried for a communication status from the other communication device,
A communication device comprising: a status notification message transmitting unit that transmits a status notification message to the another communication device when receiving the status monitoring message and desiring to receive the permission message. A system including a communication device that performs communication via a network and a request communication device that requests data transmission,
Permission message transmission means for transmitting a permission message for permitting communication to the plurality of request communication devices, data transmission request reception means for receiving a data transmission request including a code capable of identifying the request communication device desired for communication, State monitoring message transmitting means for transmitting a message for monitoring the communication state to a request communication device that does not want the communication, and a state for receiving a status notification message that wants to receive the permission message from the request communication device that does not want the communication Notification receiving means, a bandwidth allocation storage device storing the number of requested communication devices requesting the communication and the number of request communication devices not requesting the communication updated each time the data transmission request is received and the status notification message is received, and the communication The number of requesting communication devices for which the number is desired, and the relationship between the detected number and the bandwidth of the network A band calculating means for calculating a band used for communication by the requesting communication device desiring each communication, a code capable of identifying the requesting communication device requesting the band and the communication; A communication device comprising a band allocating unit for performing allocation;
Permission message receiving means for receiving a permission message for permitting communication from the communication device, and when requesting the communication, requesting the data transmission request for transmitting the data including a code capable of identifying the communication device. A data transmission request transmitting means for transmitting to the communication apparatus, a state monitoring message receiving means for receiving a state monitoring message for asking a communication state from the communication apparatus when the data transmission request is not transmitted, receiving the state monitoring message, and A communication system comprising: a request communication device including a status notification message transmitting unit that transmits a status notification message to the communication device when receiving a permission message. Transmitting a permission message permitting communication to the plurality of other communication devices via the network;
A step of receiving a data transmission request including a code capable of identifying the other communication device that desires the communication from another communication device that desires the communication that has received the permission message,
A step of transmitting a state monitoring message for monitoring a communication state to another communication apparatus that does not desire communication that did not receive the data transmission request,
From the other communication device that does not want the communication that received the state monitoring message, receiving a state notification message that wants to receive the permission message,
Storing the number of other communication devices that desire the communication and the number of other communication devices that do not want the communication, updated in each reception of the data transmission request and each reception of the status notification message, in a band allocation storage device,
Detecting the number of other communication devices that desire the communication, the relationship between the detected number and the bandwidth of the network, calculating the bandwidth used by each other communication device that wants the communication for communication,
Allocating the entire band used for communication based on the band and a code capable of identifying the other communication device that desires the communication.

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