JPH10256993A - Access system control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain normal bi-directional communication without setting a serial number in a subscriber's side transmitting device, or previously communicating this to a station side transmitting device by using a software address such as an IP address for identifying a subscriber. SOLUTION: Relating to a station side transmitting device 1, an optical signal 5 in which a time slot is assigned to each subscriber is transmitted from an optical transmitting circuit 2, and inputted through a bi-directional optical multiple separating circuit 4 to an optical star coupler 7, and the light is branched only into the number of connected subscribers, and transmitted to each subscriber. In a subscriber's side transmitting device(ONU) 11, this signal is inputted through an optical multiple separating circuit 10 to an optical receiving circuit 12, and only the signal to the destination of its own station is selected from input signals 8, and received and reproduced. On the other hand, an incoming signal 9 is transmitted from an optical transmitting circuit 13 in a timing controlled burst configuration so as not to be bumped when it is synthesized by the coupler 7. An incoming signal 6 is inputted through the separating circuit 4 to the circuit 3 as a continuos signal, and identified and reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmission system in a subscriber system, wherein a serial number for specifying an individual is not set in advance in a subscriber side transmission device, and such an identification number is previously set in a station side transmission device. The present invention relates to a method for performing bidirectional communication between a station-side transmission device and a plurality of subscriber-side transmission devices without having to input the information to a user.

[0002]

2. Description of the Related Art As an optical subscriber transmission system, a passive double star configuration in which an optical star coupler is installed on an optical transmission line between a subscriber's house and a station and downstream signal light from the station is distributed to a plurality of subscribers. Optical transmission system (PDS system) is proposed and realized (Tetsuya Kaneda, Noriyuki Terada: "High-speed optical (ATM-P
DS) Access system "). In this system, the multiplexing / demultiplexing of the uplink signal sent from the subscriber to the station is performed using a time division access system (TDMA). Can be achieved.

In the PDS system, since the distance from the station varies depending on each subscriber, in order to perform uplink TDMA normally, this distance (or transmission time) must be recognized by the station in advance. Need to be kept. For this reason, in the conventional PDS method, generally, first, polling, which is an uplink signal transmission request, is individually performed for all subscribers, and each subscriber-side transmission device receives the uplink signal and transmits the uplink signal. And a method of sequentially measuring the round-trip transmission time between each subscriber and the station.

In order to perform this method, it is necessary to individually poll the subscribers. For this reason, each subscriber-side transmission device has a unique serial number set beforehand at the time of shipment, and it is necessary to notify the station-side transmission device of this number before performing communication and initialize the system. there were.

[0005]

As described above, in the conventional PDS system, it is necessary to set a serial number in advance in the hardware of the subscriber-side transmission device, and to set this before starting communication. It was necessary to separately notify the station side transmission device. Setting a serial number in hardware in this way requires consultation between device manufacturers in order to assign a unique number in advance without duplication, or for a communication line provider, a subscriber transmission device. There is a problem that a database for managing the information becomes huge. Also, separately notifying the serial number to the station side has hindered user convenience and expandability of the system.

According to the present invention, a subscriber system, such as a PDS, configured to receive the sum of uplink signals from each subscriber at a station side by using a software address such as an IP address for subscriber identification. An object of the present invention is to provide a control method of an access system capable of performing normal bidirectional communication without setting a serial number in a transmitter side device and notifying the station side transmission device of the serial number in advance.

[0007]

According to the optical transmission method of the present invention, a software address such as an IP address is replaced with a software address such as an IP address instead of setting a serial number in advance in the hardware of the subscriber-side transmission device. The subscriber is identified by this. As a method of recognizing the software address and the distance between station subscribers on the station side, first, all subscribers are polled simultaneously. After receiving this polling signal, each subscriber-side transmission device returns an upstream signal after a predetermined period, and writes a software address stored in its own device into this signal. The station-side transmission device receives this uplink signal, but stores the software address and the round-trip transmission time of the subscriber who has been normally received.

When signals from all the subscribers can be received normally, bidirectional transmission can be started using these data. However, signals from a plurality of subscribers collide on the station side. In some cases, normal reception may not be possible. In this case, the polling is performed again, but the software address of the subscriber successfully received in the previous polling is written in the polling signal, and the subscriber corresponding thereto does not return the uplink signal. For the other subscribers whose upstream signal collided in the previous polling, the random delay value is calculated by a numerical value generated appropriately in each subscriber-side transmission device and a software address appropriately calculated. Is set, and the response to polling is delayed by this delay value and transmitted. In addition, by writing the value of the delay in the return signal, the equivalent transmission time of the round trip can be inversely calculated in the station side transmission device.

[0009] Since a reply is returned at a timing different from that of the previous polling due to the random delay for each subscriber, a signal that has collided last time may be normally received. The software address, the round-trip transmission time, and the random delay value are stored for the subscribers who have been able to receive the data normally, and the same polling is repeated for the subscribers that have not been able to receive the data normally.

By repeating such polling, signals from all subscribers can be received normally, and at that time, all software addresses and round-trip transmission times including equivalent ones are transmitted to the station. Since it can be grasped on the side, two-way communication becomes possible.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration example of an optical subscriber system to which the control method of the present invention is applied. Station-side transmission device 1
In the optical signal, an optical signal (5 in the figure) to which a time slot is assigned to each subscriber is transmitted from the optical transmission circuit 2, and is input to the optical star coupler 7 via the bidirectional optical demultiplexing circuit 4, In the optical star coupler 7, light is split into the number of connected subscribers and sent to each subscriber. In the subscriber-side transmission device (ONU) 11, the signal is input to the optical receiving circuit 12 via the bidirectional optical demultiplexing circuit 10, and the input signal (8 in the figure)
, Select only the signal addressed to the own station, and perform reception and reproduction.

On the other hand, the upstream signal is transmitted from the optical transmission circuit 13 in a burst form whose timing is controlled so as not to collide when multiplexed in the optical star coupler 7 as shown in FIG. The upstream signal becomes a continuous signal shown in FIG. 6 and is input to the optical receiving circuit 3 via the optical multiplexing / demultiplexing circuit 4, where it is identified and reproduced. Here, the optical multiplexing / demultiplexing circuit can be realized by using an optical circulator, or by using an optical multiplexing / demultiplexing circuit when the wavelengths of upstream and downstream are different.

The time multiplex access method (TDMA)
Method), the distance from the station varies depending on each subscriber.
In order to perform DMA normally, it is necessary for the station to recognize this distance (or transmission time) in advance. Conventionally, a hardware serial number allocated to the subscriber-side transmission device has been used as a means for grasping the distance.

FIG. 2 shows a control method according to the present invention.
It shows about the case of. In this figure, the horizontal axis indicates the position of each subscriber starting from the station, and the vertical axis indicates the time. Before starting communication between the station and the subscriber, it is assumed that a non-overlapping software address such as an IP address in the TCP / IP protocol is written in the nonvolatile memory of the subscriber-side transmission device.

As a procedure for performing the initial setting of communication, first, all subscribers are polled simultaneously by using a time slot shown in FIG. Reference numeral 18 in the figure shows the locus of the transmission of the downlink signal. Each subscriber receiving this polling information returns an up signal shown in FIG. 15 immediately or after a preset hold time has elapsed. 1 in the figure
Reference numeral 9 denotes a locus of the upstream signal transmitted from each subscriber. In the upward reply signal, a software address stored in the own device is written by a specific method.
The station-side transmission device receives this uplink signal, and when it is normally received (16 in the figure), stores its software address and the round-trip transmission time from when the polling signal is transmitted until the uplink signal arrives. If signals from all subscribers can be received normally, bidirectional transmission can be started using these data.

As shown at 17 in the figure, when signals from a plurality of subscribers collide on the station side, the collision is detected and polling is performed again. For signal collision, a method of confirming the length of the polling reply data (15 in the figure), a method of providing an error detection function to the reply data in advance and detecting this, and determining the first and last bit patterns of the reply data In advance, it is possible to detect by a method of checking this, a method of combining them, or the like.

In the second polling shown at 20 in the figure, the software address of the subscriber successfully received in the previous polling is written in the polling signal. Even if the subscriber corresponding to this address receives the polling signal, the subscriber does not transmit the return uplink signal. At this time, for a subscriber whose address is not described in the polling signal, that is, for a subscriber whose upstream signal collides with the previous polling, a numerical value randomly generated in each subscriber side transmission device and a software address are appropriately used. , A random delay value is set, and a reply to polling is transmitted with a delay of this delay value (21 in the figure).

In the above calculation, it is desirable that the difference between subscribers as a result of repeating the calculation a plurality of times be different each time if the addresses are different even if the random numerical values match. Specifically, it is desirable that the calculation is not a simple sum or difference but a non-linear calculation such as a combination of a product and a quotient. In addition, by writing the amount of delay of the operation result in the return signal, the equivalent transmission time of the round trip can be inversely calculated in the station side transmission device.

By repeating such a polling operation, a reply signal can be normally received for all subscribers. At this point, by further polling the software addresses of all the subscribers, for example, the optical signal strength is extremely low, and the automatic gain adjustment circuit of the electric circuit suppresses the circuit gain in accordance with the high-strength signal. As a result, even when there is a signal that has not been received normally, another uplink signal is not transmitted, so that this can be detected and the same control can be performed.

At this time, the round-trip transmission time equivalently obtained from the software address and the delay amount can be grasped on the station side for all the subscribers, so that ordinary two-way communication can be performed. An example of the normal communication is shown as a normal communication mode in FIG. The transmission timing of the uplink signal shown in FIG. 24 is controlled based on the TDMA system based on the delay amount obtained by the above control procedure, so that uplink signals (23 in the figure) from a plurality of subscribers can be continuously received. .

The embodiment of the present invention has been described above in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and changes in design and the like may be made without departing from the gist of the present invention. Even if there is, it is included in the present invention.

[0022]

According to the transmission method of the present invention, it is possible to set a hardware address in the subscriber-side transmission device in advance, or to notify the station side in advance of this and perform the initial setting without having to perform initialization.
As long as the device satisfies the communication specifications, communication with the subscriber system is possible only by connecting to the subscriber line and writing a software address such as an IP address. This allows
This has the effect of improving the convenience of the user and the expandability of the system, and eliminating the necessity for adjustment between the companies involved in the production of the device.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of an optical subscriber system to which an access system control method according to an embodiment of the present invention is applied.

FIG. 2 is an explanatory diagram illustrating an example of an access system control method according to the embodiment;

[Explanation of symbols]

1 ... station-side transmission device 2 ... station-side optical transmission circuit 3 ...
Station-side optical receiving circuit, 4,10 ... optical demultiplexing circuit, 7 ...
... optical star coupler, 11 ... subscriber side transmission device, 12
…… Subscriber side optical transmission circuit 13 …… Subscriber side optical reception circuit

Claims (3)

[Claims] 1. An access system control method for controlling an optical subscriber system for performing bidirectional optical transmission between a station in which a subscriber line exchange is located and a plurality of subscribers, a function of storing address numbers in a memory. Using a subscriber-side transmission device equipped with, a software address number that is not duplicated among multiple subscribers is input in advance, and a polling signal for requesting a reply is transmitted from the station to all subscribers first. The subscriber sends a reply signal describing the software address number stored in its own memory to the station immediately after receiving the polling signal or after the elapse of a preset hold time, and the station receives all the reply signals. When a signal from each subscriber is input to the station, it is determined whether or not a collision has occurred. When the collision does not occur for all the subscribers, the processing is terminated, and a transition is made to the normal communication state based on each subscriber's software address number and the round-trip transmission time. If this occurs, a polling signal describing the software address number of the subscriber that has been successfully received is transmitted again, and among the subscribers receiving this re-polling signal, the subscriber has the software address number described in the polling signal. The subscriber does not reply, and the subscriber who does not have this number defines the hold time as the value obtained as a result of performing a predetermined operation on the random number generated by the device and its own software address number Write this hold time in the reply signal to the polling signal, and delay this hold time from the arrival of the polling signal. A reply signal is sent to the station, and the above-mentioned re-polling procedure is repeated as long as a collision is detected in the reply signal. When the station knows the software address numbers and the round-trip transmission times of all the subscribers, the communication state is normal. An access system control method, comprising: 2. The access control method according to claim 1, wherein the software address number is an IP address in a TCP / IP protocol. 3. The access control method according to claim 1, wherein the calculation for obtaining the hold time is performed by a software address of each subscriber even if the random numbers match. An access system control method characterized in that if the numbers are different, the deviation between subscribers as a result of repeating the operation a plurality of times is a different operation each time.