JP2003273867A - Communication control system and communication control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable high-speed transmission and build an economical structure for a communication control system and a communication control method, in which plural optical subscriber line terminators are connected in a ring shape. <P>SOLUTION: In the communication control system and the communication control device, an optical subscriber line local termination device 4 and plural optical terminator 2 are connected via an optical fiber concentrator 3. The optical subscriber line local termination device 4 makes transmission and reception control of data frames, including a frame discriminator and makes sending control of an access control frame including a frame discriminator within a predetermined time interval. The optical concentrator 3 provides a construction, including optical fiber transmission lines connecting between the optical subscriber line local termination device 4 and the plurality of subscriber line terminators 2 as an access control frame goes around the ring. The plurality of subscriber lines 2 receiver the access control frame, acquits a transmission right, send transmission data sent from a terminator as a data frame by the acquisition of the transmission right, and send repeating the access control frame. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides an optical fiber assembling device between an optical subscriber line terminal device on the subscriber side and an optical subscriber line terminal device on the network side to transmit and receive data by optical signals. Communication control system and communication control method.

[0002]

2. Description of the Related Art With the spread of the Internet, data communication traffic has surpassed telephone (voice) traffic, and access to the Internet is increasing not only from companies but also from general households. It is going all the way. Access from ordinary households is based on existing analog telephone networks and ISDN (Integrated S).
There are many dial-up connections using services Digital Network, but xD
SL (Digital Subscriber Lin)
The spread of always-on services using the technology of e) is also increasing.

ADSL (Asymm) in xDSL technology
etric Digital Subscriber
Line) can have a maximum transmission rate of 8 Mbps in the downstream direction from the station side to the subscriber side and a transmission rate of 640 kbps in the upstream direction. The main line system of a communication system needs to cope with such an increase in the number of subscribers of high-speed transmission.

The maximum available transmission speed is 56 kbps for analog telephone lines, 64 kbps to 128 kbps for ISDN, 128 kbps to 2 Mbps for CATV systems, 256 kbps to 8 Mbps for ADSL, and a wireless interface. If used, 512 kbps to 2 Mbps; if optical fiber is used, 10 Mbps to 100 Mbps
ps.

Subscriber service using optical fiber is FTT
It is known as H (Fiber To The Home), and in this FTTH service, by using an optical fiber, as described above, 100 Mbps.
It is expected that various content distributions and new businesses will emerge as it will be able to provide the broadband services of.

The conventional FTTH system is, for example, as shown in FIG.
The configurations shown in (A) and (B) are generally used. (A) of the figure is an SS (single star) that connects the optical subscriber line terminal device 104 and the subscriber's terminal device 101 in a one-to-one relationship.
A system is shown, 102 is an optical subscriber line terminating device (ONU),
103 is an optical fiber splicing device, 105 is an IP (Internet) network, and 106 and 107 are networks of telecommunications carriers. Further, the terminal equipment 101 and the optical subscriber line terminating device 102 are connected by a 100BASE-TX cable standardized as IEEE802.3u, and the optical subscriber line terminating device 102 and the optical subscriber line terminating device 104 are connected to each other. IEEE 802.3 is connected to the fiber splicing apparatus 103.
The case where the optical fiber is connected by an optical fiber of 100BASE-FX standardized as u is shown.

FIG. 13B shows a PDS (Passiv).
e Double Star) method,
1 is a terminal device of a subscriber, 112 is an optical subscriber line terminating device (ONU), 113 is an optical fiber splicing device, 114 is an optical subscriber line terminal device, 115 is an IP network, 116 and 117 are telecommunications carriers, etc. , 118 is an optical coupler. In this case, the space between the optical coupler 118 and the optical fiber splicing device 113 of the optical subscriber line terminal device 114 is used for the terminal equipment 111 of each subscriber by time division.

[0008]

[Problems to be Solved by the Invention] FIG.
In the configuration of the SS system shown in (1), the upstream direction and the downstream direction can be communicated in the full-duplex mode of 100 Mbps, and by using the standardized IEEE802.3u configuration, the configuration can be relatively inexpensive. However, since one-to-one connection is made with the subscriber's terminal equipment 101, the number of optical subscriber line terminal equipment 104 increases corresponding to the number of terminal equipment 101, so that the installation space on the station side is increased. In addition, the increase in cost due to the increase in the number of devices becomes a problem.

In the configuration of the PDS system shown in FIG. 13B, the common optical subscriber line terminal device 114 may be provided for the terminal devices 111 of a plurality of subscribers. With the increase in the number of subscriber terminal devices 111, it is possible to avoid the problem of increased installation space and cost on the station side.
In this PDS system, for example, STM (Synch)
50M of the Ronus Transfer Mode)
It is known that the bps band is used by time division multiplexing to enable communication with the terminal devices 111 of a maximum of 32 subscribers. However, the band of IEEE802.3 is 20
Only Mbps can be secured, but there is a problem that efficiency is not good. An object of the present invention is to improve communication efficiency with a relatively inexpensive structure.

[0010]

A communication control system according to the present invention will be described with reference to FIG. 1. An optical fiber group is provided between an optical subscriber line terminal device 4 and a plurality of optical subscriber line terminal devices 2. A communication control system connected via a device 3,
The optical subscriber line terminal device 4 has a configuration of performing transmission / reception control of a data frame including a frame identifier and transmission control of an access control frame including a frame identifier at a predetermined time interval. The subscriber line terminating device 4 and the plurality of subscriber line terminating devices 2 are configured to include an optical fiber transmission line 9 that connects the subscriber line terminating device 2 so that the access control frame can make one round. Is configured to receive an access control frame, acquire a transmission right, and transmit the transmission data from the terminal device as a data frame by acquiring the transmission right.

Further, the optical subscriber line terminal device 4 generates an access control frame at a predetermined time interval and sends the access control frame to the optical subscriber line terminal device 2 via the optical fiber assembling device 3 so that the access control frame goes round. Thus, when the reception is not possible within a predetermined time, it is determined that a failure has occurred. Further, the optical subscriber line terminating device 2 receives the access control frame and acquires the transmission right, and by the acquisition of the transmission right, the transmission data from the terminal device 1 is transmitted by the data frame including the frame identifier and addressed to itself. The data frame is received and transferred to the terminal device 1, and the access control frame is relayed to the other optical subscriber line terminating device 2 or the optical subscriber line terminal device 4 via the optical fiber collecting device 3. I have.

Further, the optical fiber assembling apparatus 3 includes a path switching section for switching the path of the optical fiber transmission path, and between the path switching section and the optical subscriber line terminal device 4 and the plurality of optical subscriber line terminal devices 2. An interface process for disconnecting the fault-occurring device by controlling the path switching unit by determining a fault occurrence based on a detection signal from the transmission / reception module and a detection unit that detects the optical signal level And a part.

Further, according to the communication control method of the present invention, the optical subscriber line terminal device 4 and a plurality of optical subscriber line terminal devices 2 are connected via the optical fiber collecting device 3 so as to form a ring network. A communication control method for performing data communication according to the method, wherein the optical subscriber line terminal device 4 sends an access control frame including a frame identifier at predetermined time intervals,
The optical subscriber line terminating device 2 which has received the access control frame via the optical fiber collecting device 3 acquires the transmission right and transmits it as a data frame including a frame identifier when it has transmission data from the terminal device 1, The process includes receiving a data frame addressed to the device itself, transferring the data frame to the terminal device 1, and relaying the access control frame.

Further, the access control frame has a maintenance information field including address bits corresponding to the address of the optical subscriber line terminating device 2, and the optical subscriber line terminating device 2 relays the access control frame and sends its own device. The corresponding address bit is set and transmitted, and the optical subscriber line terminal device 4
Can include the step of monitoring the connection status of the optical subscriber terminal device 2 according to the address bits of the maintenance information field. The maintenance information field of the access control frame includes address bits at the address corresponding positions of the plurality of optical subscriber line terminators 2 and bits indicating a test request and a test result at the address corresponding positions. A process of notifying the optical subscriber line terminal device 4 of the connection state of the optical subscriber line terminal device 2 and the test result according to the test request can be included.

The method may also include the step of transmitting the access control frame with an interframe gap with respect to the data frame. In addition, access control frame,
A fixed length that is sufficiently shorter than the interframe gap between data frames may be included in the interframe gap and transmitted.

Further, in the detecting section of the transmitting / receiving module of the optical fiber assembling apparatus 3, the optical signal level transmitted / received to / from the optical subscriber line terminating apparatus 2 is detected and notified to the interface processing section. It is possible to include a process of determining the presence / absence of a failure, controlling the path switching unit to switch the optical fiber transmission line when the failure occurs, and disconnecting the optical subscriber terminal device in which the failure has occurred.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of an embodiment of the present invention, in which 1 is a terminal device of a subscriber, 2 is an optical subscriber line terminating device (ONU), 3 is an optical fiber collecting device, 4 Is an optical subscriber line terminal device, 5 is a local IP (Internet) network,
Reference numerals 6 and 7 are networks of telecommunications carriers, 8 is a ring network, and 9 and 10 are optical fiber transmission lines.

The ring network 8 includes an optical subscriber line terminating device 2 corresponding to each terminal equipment 1 of a plurality of subscribers.
And the optical subscriber line terminal device 4 are connected to each other via the ring-shaped optical fiber transmission line 9 of the optical fiber assembling device 3, and the optical fiber transmission line 10 between the optical subscriber line terminal device 2 and Is configured with two optical fibers or full optical duplex communication with one optical fiber.

FIG. 2 is an explanatory view of a ring network. The same reference numerals as those in FIG. 1 denote the same parts, SM is an optical transmission module, RM is an optical reception module, CN is an optical connector section, 4a is a transmission / reception processing section, and 4b. Indicates an interface section. The optical fiber transmission line 9 of the optical fiber assembling device 3, the optical connector unit CN, the optical receiving module RM and the optical transmitting module SM of each optical subscriber line terminating device 2, the optical fiber transmission line 10, and the optical subscriber line. The optical receiving module RM, the optical transmitting module SM, and the transmission / reception processing unit 4a of the terminal device 4 constitute a ring network for transmitting an optical signal.

Therefore, each optical subscriber line terminating device 2 has a one-to-one correspondence with the optical fiber assembling device 3.
The optical fiber assembling device 3 transmits the optical signal from the optical subscriber line terminal device 4 to each optical subscriber line terminating device 2 via the ring network, and each optical subscriber device The line terminating device 2 identifies the address information for the own optical subscriber line terminating device 2, receives the optical signal, and transfers the optical signal not addressed to the own optical subscriber line terminating device 2 as it is.

FIG. 3 is an explanatory diagram of the frame structure.
(A) is an IEEE802.3u (100BASE-T
X) frame, (b) IEEE802.3u (10
0BASE-FX) frame, (c) a data frame used in the present invention, (d) an access control frame, and (e) a frame identifier FID. IP
G is an inter frame gap
e Gap) and PA are preamble fields (Pre
SMB is a start frame delimiter (Sta).
rt Frame Delimiter, DA is the destination address (Destination Address)
s), SA is the source address (Source Addr)
ess), L / T is length / type (Length / Ty
pe), LLC is transmission data, FCS is a frame check sequence (Frame Check Sequence).
e) is shown.

The IFG also has an interframe gap (I
inter Frame Gap), SSD is the start stream delimiter (Start of Stream Dem).
limiter) and ESD are end stream delimiters (End of StreamDelimiter),
FID is a frame identifier (Frame Identifier).
ier) and MI are maintenance information (Management I
nformation) and PAD are adjustment bits (Pa
dending Bits), D / A is a frame identifier (D
ata / Access Identifier), I /
D indicates an insertion position identifier (IPG / Data), and R indicates a reserved bit (Reserved Bit). D / A =
“0” indicates a data frame, and D / A = “1” indicates an access control frame. I / D = "0" indicates that the access control frame is inserted in the interframe gap IPG, and I / D = "1" indicates that the access control frame is placed in the interframe gap IFG like the data frame. Indicates that it is transmitting. The number above each field indicates the number of bytes.

Data is transmitted between the terminal equipment 1 and the optical subscriber line terminating device 2 by, for example, the frame shown in FIG. 3A, and the optical subscriber terminating device 2 and the optical fiber assembling device 3 are transmitted. Data is transmitted between the optical terminal and the optical subscriber line terminal device 4 via the optical fiber transmission lines 9 and 10 which form the ring network 8 by the data frame shown in FIG. This frame corresponds to a frame structure in which a frame identifier FID indicating a data frame or a control frame is added to the frame shown in FIG. 3B by using one byte of the preamble field PA.

The access control frame shown in (d) of FIG. 3 includes the frame identifier FID shown in (e) of FIG. 3, is generated in the optical subscriber line terminal device 4, and is generated in the optical fiber assembling device 3. Transmission is performed via the optical fiber transmission line 9 between the optical fiber transmission line 9 and the optical subscriber line terminating device 2, and the control device causes the terminal device 1 to transmit data from the optical subscriber line terminating device 2. You get the right.

The optical subscriber line terminal device 4 sends the data from the IP network 5 through the optical fiber assembling device 3 as described above in the frame structure shown in FIG. The subscriber line terminating device 2 identifies the destination address DA and, when addressed to itself, converts the frame structure shown in (c) of FIG. 3 into the frame structure shown in (a) of FIG. Transfer to the terminal device 1.

FIG. 4 is an explanatory diagram of the transmission format of the access control frame, and (a) and (b) show I / D =
The case where "1" is set is shown. As shown in (a),
An inter frame gap IFG is formed between the data frames DATA, the control frame has a minimum frame structure of 64 bytes, and the inter frame gap IF is formed before and after the control frame as shown in (b).
It is transmitted after G.

Further, FIGS. 4C and 4D show the above-mentioned I / D.
4C shows the same frame structure as that of (a), but the interframe gap IFG has a structure of 12 bytes or more, and the interframe gap IFG shown in FIG. As shown in d)
An access control frame having a fixed length of, for example, 10 bytes, which is shorter than the inter frame gap IFG, is inserted and transmitted.

FIG. 5 is an explanatory view of the maintenance information field of the control frame, and shows the maintenance information field MI of the control frame shown in FIG. 3D, which maintenance information field MI has a structure of 0 to 61 bytes. Is possible, 3
In a system in which two optical subscriber line terminators 2 are connected, the address bits A0 to A have a 4-byte structure.
31 is assigned to each optical subscriber line terminating device 2. Upon receiving this control frame, each optical subscriber line terminating device 2 sets one of the bits A0 to A31 indicating the address position of its own device to "1" and sends it out. Therefore, the optical subscriber line terminal device 4 can monitor the connection status of the optical subscriber line terminal device 2.

FIG. 6 is a detailed explanatory diagram of the maintenance information field of the control frame.
32 bytes, A0 to A31 are address bits of unique address corresponding positions of the 32 optical subscriber line terminating devices shown in FIG. 5, R0 to R31, R32 to R
64 is a reserved bit, LF0 to LF31 are test result bits set to "1" when the link integrity test of 100BASE-FX corresponding to addresses A0 to A31 is OK, and LT0 to LT31 are addresses A0 to A3.
1 is a test result bit set to "1" when the link integrity test of 100BASE-TX is OK, and LR0 to LR31 are loop request bits set to "1" when a loop request corresponding to addresses A0 to A31 is set, LA0
To LA31 are response bits which are set to "1" at the time of response corresponding to the addresses A0 to A31, and E0 to E31 are address A0.
~ EQP information bits corresponding to A31, Ri0 to Ri31
Indicates an R-INH bit indicating an inhibit state corresponding to addresses A0 to A31. The optical subscriber line terminal device 4 is
Based on the contents of the maintenance information field MI of the control frame, the status of each optical subscriber line terminating device 2 connected to the ring network 8 can be monitored as a status having almost no influence on traffic.

FIG. 7 is a diagram for explaining the system configuration of the ring network according to the embodiment of the present invention. The same reference numerals as those in FIG.
22 is a bidirectional bus (BWB), 23 is a supervisory control terminal, 2
Reference numeral 4 denotes an interface board for the monitor control terminal. The optical subscriber line terminal device 4 connects a plurality of interface boards 21 and a regional IP network (not shown) via a bidirectional bus 22, and the interface board 24 is connected to the interface board 24.
3 is also connected, and the optical fiber collecting apparatus 3 is connected to the interface board 21.

The optical fiber assembling device 3 and the optical subscriber line terminal device 4 are provided in the station building, and are connected to the distributed optical subscriber line terminal devices 2 through the optical fiber transmission line 10. The ring network including the optical fiber transmission line 9 of the optical fiber assembling apparatus 3 transmits the transmission / reception data as an optical signal frame.

FIG. 8 is an explanatory diagram of the optical subscriber line terminating device and the optical subscriber line terminal device, and FIG.
2B is a block diagram of an optical subscriber line terminal device. The optical subscriber line terminating device 2 of (A) of the figure includes an optical transmission / reception unit 31 including an O / E / E / O conversion unit 32 that performs mutual conversion between an electric signal and an optical signal, and 100BASE-FX.
Physical layer termination unit 33 and access control frame termination unit 34
And 100BASE-TX physical layer terminating unit 35 and a transmission transformer 36, and the 100BASE-FX physical layer terminating unit 33 and 100BASE-TX physical layer terminating unit 34 are used to provide a media unique interface MII (Media).
Independent Interface).

The optical fiber assembling device 3 and the optical transmitter / receiver 31 are connected by an optical fiber transmission line. In this case, as shown in FIG. 2, two optical fiber transmission lines 10 are connected.
Although it is easy to understand the configuration for connection by means of, the optical fiber assembling device 3 and the optical transmission / reception unit 31 may be provided with means for separating and combining transmitted / received optical signals so that they can be connected by a single optical fiber transmission line. Further, in the 100BASE-FX physical layer terminating unit 33, transmission / reception control of the data frame shown in FIG. The transmission / reception control of the control frame shown in 3 (d) is performed. Thereby, the data is transferred to the terminal device connected to the own device and the data is transmitted from the terminal device. in this case,
The frame identifier FID can identify a data frame or an access control frame.

The optical subscriber line terminal device 4 shown in FIG.
Is an O / E / E / O conversion unit 41 that performs mutual conversion of electric light.
Optical transceiver 41, including 100BASE-FX physical layer terminator 43, access control frame terminator and generator 4
4, a BWB interface processing unit 45, and an optical connector 46, and includes 100BASE-FX physical layer terminating unit 43.
The media unique interface MII (Media) by the access control frame termination unit and the generation unit 44.
Independent Interface). The BWB corresponds to the bidirectional bus 22 in FIG.

The optical fiber assembling device 3 and the optical transmitter / receiver 41 are connected by a single optical fiber transmission line for bidirectionally transmitting an optical signal, or are separately transmitted for transmission and reception of an optical signal. Connected by two optical fiber transmission lines,
The BASE-FX physical layer terminating unit 43 controls transmission / reception of the data frame shown in FIG. 3C to be transmitted to / from the optical fiber collecting apparatus 3, and the access control frame terminating unit and the generating unit 45 receive the data. The access control frame is terminated and the access control frame to be transmitted is generated.

FIG. 9 is an explanatory diagram of communication control.
(E) is a data frame and an access control frame AM
The transmission / reception status of F is shown, the station corresponding to the optical subscriber line terminal device 4 is the active station A, the stations corresponding to the optical subscriber line terminal device 2 are the standby stations B, C, D, and the optical fiber assembling device 3 is shown. A configuration is shown in which the transmission lines are connected in a ring shape via.

FIG. 9A shows the access control frame AMF shown in FIG. 3D from the active station A.
Is generated and transmitted, the next standby station B
From the terminal equipment (not shown) to the standby station D
3 has the data for the terminal device connected to the access control frame AMF, the transmission right is acquired by receiving the access control frame AMF, and the data addressed to the standby station D shown as B → D in the access control frame AMF shown in FIG. (C) is transmitted as a data frame in the frame format, and the access control frame AMF is also relayed and transmitted.

Next, as shown in FIG. 9B, in the standby station C, since the data frame from the standby station B is not the data frame addressed to the own device, it is relayed as it is and accessed. The transmission right is acquired by receiving the control frame AMF, and the data C → A addressed to the active station A is converted into a data frame having the frame format shown in FIG. To relay.

Next, as shown in FIG. 9 (c), the standby station D receives a data frame, and the data frame shown as B → D is received by identifying that it is addressed to itself. For example, the received data is processed and transferred to a terminal device (not shown) in the frame format shown in FIG. 3A, and the data frame shown as C → A is not addressed to the own device, and thus is relayed and transmitted. , And relays the access control frame AMF.

Next, as shown in (d) of FIG. 9, in the active station A, the data frame indicated as C → A is addressed to its own device, so this is received and processed.
Moreover, the access control frame AMF is generated and transmitted.
Next, as shown in (e) of FIG. 9, when receiving the access control frame AMF, the standby station B relays and outputs the access control frame AMF if there is no transmission data. Hereinafter, other standby stations will perform the same processing.

FIG. 10 is an explanatory diagram of an embodiment provided with a failure relieving means. The same reference numerals as those in FIG.
6 is an interface processing board (INFO board), 51 is an interface processing section (INFO section), 52 is a path switching section,
53 is a switch unit, 54 is a detection unit, and 56 and 57 are transmission / reception modules. Further, the active station A in FIG. 9 is shown as an optical subscriber line terminal device 4, and the standby stations B, C and D are shown as an optical subscriber line terminal device 2.

The path switching unit 52 of the optical fiber collecting apparatus 3
Includes a switch unit 53, and optical signal switch means or path switching means known as an optical cross connect unit can be applied. The switch unit 53 including an optical switch is an interface processing unit. Controlled from 51. The transmission / reception modules 56 and 57 each include a detection unit 54, and input a detection signal such as an optical signal level to the interface processing unit 51. The interface processing unit 51 determines whether the optical signal is interrupted, the optical signal level is lowered, or the like based on the detection signal, and controls the path switching unit 52.

For example, when a failure occurs in the standby station C, the access control frame AMF cannot be relayed and the detection signal from the detection unit 54 of the transmission / reception module 57 corresponding to the standby station D becomes abnormal. Thereby, the interface processing unit 5
1 is a path switching unit 52 corresponding to the standby station C
The switch unit 53 is controlled to bypass, for example. Thereby, the access control frame and the data frame from the standby station B can be transferred to the standby station D.

The interface processing section 51 may be configured to control the path switching section 52 based on the detection of a failure as described above, but the monitoring control terminal 23 is provided with various judgment and control functions. It is also possible to provide and control the route switching unit 52 via the interface processing unit 51. For example, the supervisory control terminal 23 is provided with a ring configuration table. FIG. 11 is an explanatory diagram of this ring configuration table, including a station name and line information.
(A) of 1 shows the case where all the stations with station names A, B, C, D are normal.

Regarding the other standby stations B, C and D including the active station A connected to the optical fiber assembling apparatus 3, the active station A has a maintenance information field MI of the access control frame.
It is possible to collect whether or not it is connected to the ring network by using the address bit of the above in the monitor control terminal 23 through the interface board 24. Further, the information as to whether or not it is normal can be collected from the interface processing unit 51 via the interface boards 26 and 24.
Further, it is possible to collect information as to whether or not the alarm state is present by the test result bit shown in FIG. 6 of the maintenance information field MI.

Further, as described above, when a failure occurs in the standby station C, the information is transferred to the monitor control terminal 23. The monitor control terminal 23 sends the control information to the interface processing unit 51. Interface processing unit 51
Is the switch unit 5 of the route switching unit 52 according to the control information.
3 is controlled to perform switching control so as to bypass the standby station C. Then, the ring configuration table is updated as shown in FIG. Then, since it is possible to identify that the standby station C is not connected based on the maintenance information field MI of the access control frame, the ring configuration table is updated as shown in (c) of FIG. That is, it shows a state in which the normal stations A, B, and D are connected.

FIG. 12 is a diagram for explaining the transmission sequence of the access control frame. In the state where the active station A and the standby stations B, C and D are connected to the ring network, the access control frame AMF from the active station A is shown. To the standby station B. Standby station B
The access control frame AMF is received and relayed to the standby station C. If there is a data frame addressed to the own station, the reception process is performed, and if there is transmission data, the data frame is transmitted.

Similarly, the next standby station C also carries out the relay transmission of the access control frame AMF and the transmission / reception of the data frame, and the next standby station D also performs the same processing. Then, the standby station D relays the access control frame AMF to the active station A. Therefore, the active station A can access the access control frame AMF.
It will take a predetermined time T from the sending of the message to the return of one cycle. Therefore, access station A
The generation and transmission of the access control frame AMF is repeated at a predetermined time interval close to the time T, and the time until the access control frame AMF makes a round and returns is measured.

On the other hand, for example, when a failure occurs in the standby station B, the access control frame AM
If F cannot be relayed, active station A
Cannot receive the access control frame AMF from the standby station D even after the time T has passed,
It can be determined that a failure has occurred in any of them. Also in this case, the access control frame AMF is generated and transmitted at a predetermined time interval. For example, if the standby station B has a power failure and then power is restored,
Since the next access control frame AMF can be received and relayed and sent out, the normal state is restored.

When a failure occurs in the standby station, as shown in FIG. 10, it is possible to disconnect the standby station in the optical fiber assembling apparatus 3 from which the failure has occurred and switch to a configuration in which only normal standby stations are connected. By this path switching, the access control frame AMF is transmitted to the next standby station by bypassing the faulty standby station, and the complete access control frame AMF is returned to the active station A.

For example, 32 standby stations are connected to the active station, and addresses that do not overlap with each other are set, and the active station sets all A31 to A0 of the maintenance information field MI of the access control frame AMF to "". Set to 0 "and send. The standby station, which receives the access control frame AMF and relays it as described above, has the address bit A31 of the maintenance information field MI.
The address bit at a position corresponding to the address of the own standby station in A0 is set to "1". For example,
The standby station with address 0 sets the address bit A0 to "1" and relays it. Therefore,
The active station can grasp the connection status of the standby station from the address bit of "1" in the maintenance information field MI of the access control frame AMF which has made a round. Such processing can be performed every time the access control frame AMF is transmitted, or the maintenance information field MI can be processed at a predetermined time interval.

The active station also receives the maintenance information field MI of the access control frame AMF shown in FIG.
Are all set to "0" and transmitted. The standby station sets the bit at the position corresponding to the address of its own station to "1" when the test result bits other than the address bits A0 to A31 are not normal. Therefore, the active station can recognize the standby station in the alarm state based on the maintenance information field MI of the access control frame AMF that has gone round.

The present invention is not limited to the above-mentioned respective embodiments, but various additions and modifications can be made, and a plurality of terminal devices can be connected to the optical subscriber line terminating device 2. It is also possible that the optical subscriber line terminal device 4 and the optical fiber collecting device 3 are provided not in the same station building but in separate station buildings and are connected by an optical fiber transmission line. .

[0054]

As described above, according to the present invention, the optical subscriber terminal device 4 on the station side and the plurality of optical subscriber line termination devices 2 are provided.
Since the optical fiber assembling device 3 is provided between the optical fiber terminating equipment 3 and the optical fiber assembling device to configure the ring network 8, it is possible to deal with this by providing one optical subscriber line terminal device 4 for the plurality of optical subscriber terminating devices 2. Therefore, there is an advantage that the station side can be economically constructed. Also, a ring network is configured via the optical fiber collecting apparatus 3, and a data frame and an access control frame for giving a transmission right can be distinguished by a frame identifier, and a plurality of optical subscriber line terminating devices 2 connected to the ring network. , The transmission right can be sequentially given by the access control frame,
There is no collision of data frames on the ring network,
High-speed transmission by IEEE802.3u becomes possible. The transmission rate is not limited to 100 Mbps, but can be applied to the transmission rate of 1 Gbps or 10 Gbps above it. Further, there is an advantage that the maintenance information field MI of the access control frame can be used to recognize the optical subscriber line terminating device connected to the ring network and to confirm whether the optical subscriber line terminating device is normal or not.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a ring network.

FIG. 3 is an explanatory diagram of a frame structure.

FIG. 4 is an explanatory diagram of a transmission format of an access control frame.

FIG. 5 is an explanatory diagram of a maintenance information field of a control frame.

FIG. 6 is a detailed explanatory diagram of a maintenance information field of a control frame.

FIG. 7 is an explanatory diagram of a system configuration of a ring network according to the embodiment of this invention.

FIG. 8 is an explanatory diagram of an optical subscriber line terminal device and an optical subscriber line terminal device.

FIG. 9 is an explanatory diagram of communication control.

FIG. 10 is an explanatory diagram of an embodiment including a failure remedy means.

FIG. 11 is an explanatory diagram of a ring configuration table.

FIG. 12 is an explanatory diagram of a transmission sequence of an access control frame.

FIG. 13 is an explanatory diagram of a conventional example.

[Explanation of symbols]

1 terminal equipment 2 Optical subscriber line terminator 3 Optical fiber collecting device 4 Optical subscriber line terminal equipment 5 regional IP network 6,7 network 8 ring network 9,10 Optical fiber transmission line

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5K002 AA01 AA03 AA06 AA07 DA04                       DA05 DA11 EA05 FA01                 5K030 JL03 JL08 MB01 MD02

Claims (10)

[Claims] 1. A communication control system in which an optical subscriber line terminal device and a plurality of optical subscriber line terminal devices are connected via an optical fiber collecting device, wherein the optical subscriber line terminal device is a frame. Transmission and reception control of a data frame including an identifier, and a configuration for performing transmission control of a predetermined time interval of an access control frame including a frame identifier, the optical fiber aggregation device, the optical subscriber line terminal device and the plurality of A configuration including an optical fiber transmission line connected to a subscriber line terminating device so that the access control frame can make one round, and the plurality of subscriber line terminating devices receive and transmit the access control frame A communication control system having a configuration of acquiring a right and transmitting transmission data from a terminal device as a data frame when the transmission right is acquired. 2. The optical subscriber line terminal device generates the access control frame at predetermined time intervals and sends the access control frame to the optical subscriber line terminal device via the optical fiber collecting device,
The communication control system according to claim 1, wherein the communication control system has a configuration in which it is determined that a failure has occurred when the access control frame has not been received within a predetermined period of time. 3. The optical subscriber line terminating device receives the access control frame, acquires a transmission right, sends out transmission data from a terminal device by a data frame including a frame identifier, and transmits data addressed to itself. It is configured to receive a frame, transfer the frame to the terminal device, and relay the transmission of the access control frame to another optical subscriber line terminating device or the optical subscriber line terminal device via the optical fiber collecting device. The communication control system according to claim 1, wherein: 4. The optical fiber assembling apparatus comprises a path switching unit for switching the path of an optical fiber transmission path, the path switching unit, the optical subscriber line terminal device, and the plurality of optical subscriber line termination devices. A transmission / reception module including a detection unit that connects the two and also detects an optical signal level, and determines a fault occurrence based on a detection signal from the detection unit and controls the path switching unit to disconnect the fault occurrence device. The communication control system according to claim 1, further comprising an interface processing unit. 5. A communication control method for performing data communication by connecting an optical subscriber line terminal device and a plurality of optical subscriber line terminal devices via an optical fiber collecting device so as to form a ring network. The optical subscriber line terminal device sends out an access control frame including a frame identifier at a predetermined time interval, and the optical subscriber line terminal device which has received the access control frame via the optical fiber collecting device, Acquire the right to send,
When it has transmission data from the terminal device, it is transmitted as a data frame including a frame identifier, the data frame addressed to the own device is received and transferred to the terminal device, and the access control frame is relayed out. A communication control method comprising: 6. The access control frame has a maintenance information field including an address bit corresponding to an address of the optical subscriber line terminating device, and the optical subscriber line terminating device relays and outputs the access control frame. Sometimes, an address bit corresponding to the own device is set and transmitted, and the optical subscriber line terminal device includes a step of monitoring the connection status of the optical subscriber terminal device by the address bit of the maintenance information field. The communication control method according to claim 5. 7. The maintenance information field of the access control frame includes an address bit at an address corresponding position of the plurality of optical subscriber line terminators and a bit indicating a test request and a test result at the address corresponding position. 6. The method according to claim 5, further comprising the step of notifying the optical subscriber line terminal device of a connection state of the optical subscriber line terminating device and a test result according to a test request according to each bit position.
Alternatively, the communication control method according to item 6. 8. The communication control method according to claim 5, further comprising the step of transmitting the access control frame with an interframe gap with respect to the data frame. 9. The method according to claim 1, further comprising a step of inserting the access control frame into the interframe gap and transmitting the access control frame with a fixed length sufficiently shorter than an interframe gap between the data frames. Item 5. The communication control method according to Item 6 or 7. 10. A detection unit of a transmission / reception module of the optical fiber assembling apparatus detects an optical signal level transmitted / received to / from the optical subscriber line terminating device, and notifies the interface processing unit of the interface processing unit. In the case of the occurrence of a failure, the method includes the step of controlling the path switching unit to switch the optical fiber transmission line when the failure occurs and disconnecting the optical subscriber terminal device in which the failure has occurred. The communication control method according to claim 5.