JPH1051432A - Transmission delay absorption control method and device - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To transmit data including a frame signal from a plurality of N stations to a center station, to absorb a transmission delay caused by a difference in transmission path distance in the center station, and to transmit a frame signal of the data of the plurality of stations. It is an object of the present invention to provide a transmission delay absorption control method and apparatus capable of performing transmission delay absorption control on the basis of the frame phase of data of an unspecified station in a system for outputting data by making the same. SOLUTION: A center station has N frame synchronization circuits for performing frame synchronization of data of the respective stations, and a transmission delay time difference between stations having a maximum transmission delay time difference among the N stations is twice as large. N buffer memory circuits for storing data from each station having a capacity capable of holding the data for the time of N, and the N buffer memory circuits based on N frame synchronization information signals from the N frame synchronization circuits. And a delay control circuit for controlling reading of data stored in the memory.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission delay in a system in which it is necessary to receive framed data transmitted from a plurality of different points at one station and output the data with the frame phase of the data of each station being matched. The present invention relates to an absorption control method and its device.

[0002]

2. Description of the Related Art Conventionally, in this type of transmission delay absorption control method, a reference station is determined in advance from a plurality of stations, and a data of another station is determined based on a frame phase in data received from the reference station. Was used to match the frame phase by buffering the data. For example, the transmission delay time is the longest among a plurality of stations (farthest from the center station)
When the station is used as a reference, data of stations other than the reference station is stored in the buffer memory from the beginning of the frame, and the data of the reference station having the longest transmission delay time is received at the same time. By reading the data from the buffer memory, the data was output with the frame phases of the data of all the stations matched.

[0003]

In the above-described conventional transmission delay absorption control method, since the reference station is determined in advance, the data of the reference station does not reach the center station due to some abnormality or the data error occurs. Therefore, when frame synchronization cannot be achieved, there is a problem that other stations cannot output data by matching the frame phase of the data even though the data has arrived normally.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a transmission delay absorption control method and a transmission delay absorption control method in which data transmitted from other stations cannot be transmitted in the same frame phase due to a failure of a reference station.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a transmission delay absorption control system capable of absorbing a transmission delay on the basis of a frame phase of data of an arbitrary station and matching the frame phase of the data. It is in. For this reason, in the transmission delay absorption control method of the present invention, the transmission delay time difference between the N frame synchronization circuits for synchronizing the frames of the data of a plurality of N stations and the transmission delay time difference between the stations having the largest transmission delay time among the N stations. N buffer memories for recording data of N stations having a capacity capable of holding data for twice the time of N, and N frame synchronization information signals from the N frame synchronization circuits to the N buffer memories. The above object is achieved by providing a delay control circuit for controlling reading of stored data.

[0006]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a circuit diagram of an embodiment of a transmission delay absorption control device provided in a center station to which the transmission delay absorption control method of the present invention is applied.

[0008] The transmission delay absorption controller and frame sync circuit 1 ₁ to 1 _N and buffer memory 2 ₁ to 2 _N, which is connected by each station, consisting of delayed absorption control circuit 3 for controlling the like.

[0009] Data from the N plurality of stations input from the input terminals Din _{1 to} Din _N from each station are received by the frame synchronization circuits ₁₁ to 1 _N connected to the respective stations, and the data of Frame synchronization is achieved. Frame synchronization circuit 1 ₁ to 1 _N, when the frame synchronization of the received data can be taken, and sends a signal indicating that frame synchronization to the buffer memory 2 ₁ to 2 _N and the delay control circuit 3 has been established. Buffer memory circuit 2 ₁ to 2 _N is the frame sync circuit 1
When receiving a signal frame synchronization is established from ₁ to 1 _N, start writing from the beginning of the frame the received data to the start address of the buffer memory. Delay control circuit 3 receives a frame synchronized signal from the frame synchronization circuit 1 ₁ to 1 _N, the first frame based on the synchronized Stations among the N stations, the frame synchronization after the lapse time t outputs the read start signal to the buffer memory circuit 2 ₁ to 2 _N of stations are taken, starts reading from the top address of data written to the buffer memory circuit 2 ₁ to 2 _N. Since the station with frame synchronization is written from the beginning of the frame to the start address of the buffer memory circuit, the read data has the same frame phase. Where t
The time is the transmission delay time difference between the stations having the largest transmission delay time difference among the N stations. This time is the transmission delay time of the station having the shortest transmission delay time being Tmin and the longest being the transmission delay time. Assuming that the transmission delay time of the station is Tmax, t = Tmax−Tm
given in. The first station with frame synchronization is
The transmission delay is not limited to the shortest station, and the frame position of the other station exists within ± t time from the frame position of the first station with which the frame synchronization is established.
A station whose transmission delay time is shorter than the reference station (transmission delay time Tb of this station) (transmission delay time Ts ≦ Tb of this station)
Is, t + Tb-Ts time of the data is read out from the stored in the buffer memory circuit 2 ₁ to 2 _N. A station whose transmission delay time is longer than that of the reference station (transmission delay time of this station T1 ≧ Tb) is read out after data for the time of t + Tb−T1 is stored in the buffer memory circuit. Where t ≦ t + Tb−Ts ≦ 2t, 0 ≦ t + Tb−T1 ≦
a t, a buffer memory circuit 2 ₁ to 2 _N, in order to have a capacity capable of storing 2t time of the data can be read without causing an overflow or underflow.

In this method, even if all the stations cannot be synchronized, data is read out from the synchronized station by the above-described control, so that all the stations do not need to be synchronized. Further, a station that has been synchronized later outputs a read start signal from the delay control circuit 3 so that the station can be output in synchronization with the reference station when synchronization is established.

Even when the reference station goes out of synchronization, the delay control circuit 3 stores the timing before the out-of-synchronization, and operates at that timing. It does not affect other stations.

When all the stations are out of synchronization, the delay control circuit 3 resets the readout timing and repeats the above-described operation with reference to the station with which the first frame synchronization is established.

[0013]

As described above, according to the transmission delay absorption control method of the present invention, if any two or more of the N stations are in frame synchronization, the data of the synchronized stations can be transmitted. Since data can be output with the same frame phase, transmission delay absorption control can be performed without being affected by a predetermined state of the reference station as in the conventional method.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of a transmission delay absorption control device to which a transmission delay absorption control method of the present invention is applied.

[Explanation of symbols]

1 ₁ to 1 _N frame synchronization circuit 2 ₁ to 2 _N buffer memory circuit 3 Delay absorption control circuit

Continuation of front page (72) Inventor Jin Agematsu 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Japan Telegraph and Telephone Corporation

Claims (2)

[Claims] 1. A method of transmitting data including a frame signal from a plurality of N stations to a center station, wherein the center station absorbs a transmission delay caused by a difference in distance between transmission lines, and transmits frame signals of data from the N plurality of stations. A transmission delay absorption control method in a system which outputs the data in a synchronized manner, comprising: setting a station whose frame synchronization is first obtained as a reference station among data frames received by the center station; and And outputting the data of the synchronized station after matching the frames, and holding the timing at which the reference station is in frame synchronization even if the reference station is out of frame synchronization. As long as the data of all the stations is not out of frame synchronization, the data is output with the frame phase of each station in which the frame is synchronized. Transmission delay absorption control method characterized by. 2. An N number of frame synchronization circuits for frame synchronization of data from a plurality of N stations, and a transmission delay time difference between stations having a maximum transmission delay time difference among the N stations. It has a capacity to store twice the amount of data, and is connected to each of the corresponding N stations.
2. A transmission delay absorption control method according to claim 1, wherein said buffer memory circuits read out data stored in said N buffer memory circuits by N frame synchronization information signals from said N frame synchronization circuits. And a delay control circuit for controlling the transmission delay absorption control device.