JPH0479534A - Branch transmission method for multiplexed signals - Google Patents

Abstract

PURPOSE:To improve the line utilizing efficiency and to save a transmission disable time attended with revision of the system configuration by providing a device receiving a signal even at a time slot not participating in transfer of present station and a means extracting inter-station control information from a received bit string and analyzing a pattern of the AND on each station. CONSTITUTION:Third party stations N2, N3 not participating in communication receive the transfer of control information between two stations N1, N4 implemented by the stations N1, N4 by using AND processing of transfer signals between the two stations N1, N4 from a branch connection device 1, an AND analysis section 24 acquires information as to the state between the two stations N1, N4 and the content of communication of the 3rd stations N2, N3 or the data configuration to be set is revised and the system maintenance management is implemented. Then the band for inter-station control information transmission in a network composed of time division multiplexers 1-4 connected to the branch connection device 1 is reduced by a band equivalent one counter band independently of the number of stations in the network. Thus, the line utilizing efficiency is improved and the transmission disable time attended with revision of the system configuration is saved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a high-speed digital line and a time division multiplexing device system connected to the line via a branch connection device provided in the middle of the line. This invention relates to a branch transmission system for multiplexed signals.

[Prior Art] A branch service is a high-speed digital line service provided by NTT (Nippon Telegraph and Telephone Corporation) and others. As shown in Fig. 2, this branching service uses a logical product operation function of a branch connection device installed in the middle of a high-speed digital line to transfer a portion of all contracted time slots to time division multiplexers N1 and N2. The communication partners are used for each time slot, part of which is used for communication between N1 and N3, and the rest is used for communication between N1 and N4.

It is mainly used to reduce the total line usage charges by using lines efficiently. Based on the principle of uniform speed branching in the branching device, time slots other than the one used by the own station are also transmitted and received, so each station connected to the branching connection device uses time slots other than the one used by the own station. has the function of transmitting a logical value of 1 so as not to interfere with communication between other stations, and discarding time slots other than those received by the own station.

For example, in FIG. 2, station N4 communicates with N1 in timeslot 3, transmits logic highs in timeslots 1-1 and 2, and transmits data received in timeslots 1 and 2 (second
In a diagram? ) is discarded.In systems that apply branching equipment such as , due to this constant-velocity branching condition, each station needs to contract for the entire band, including extra time slots that it cannot use. Therefore, it has been difficult to design a system that produces cost benefits unless there are geographical conditions such as multiple stations being installed in the same area.

As a method for efficiently operating a system including such a branching device, for example, as described in Japanese Patent Laid-Open No. 64-39142, two stations that communicate temporally for a specific time slot (group) are proposed. A system has been proposed that allows changes to be made so that the system can be designed according to the amount of traffic.

[Problems to be Solved by the Invention] Even in the conventional method described above, the received information in unused time slots of the own station (? in Fig. 2) is simply discarded, and there is no substantial increase in bandwidth, so There was no improvement in constant communication capacity.

Also, when each station automatically changes time slots 1 to 1 depending on the time, if the - station's clock is out of order, data will be sent to the time slot that is communicating between other stations during the time difference.
There was a possibility of interfering with communication.

An object of the present invention is to enable transmission of more information without increasing the capacity of the line connected to one branching device. It also makes it possible to synchronize network configuration changes and time slot allocation changes in systems that include branching equipment, prevent invalid time caused by transmission data collisions between stations, and improve line performance as a system. The goal is to improve the efficiency of use.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, even in time slots other than those in which the own station is involved in transmission/reception among all time slots, the branch connection device transmits data between two stations communicating. A mechanism that allows each station to receive time slots in which it is not involved in transmission/reception by taking advantage of the ability to receive the logical product of has been established. Furthermore, in order to analyze the inter-station control information given by the logical product, an expected value table for the logical product is provided, and a means for comparing the received input signal with this table is provided. In addition, in order to facilitate the analysis of the logical product by the third station, the inter-station control information uses a transmission right, etc. to alternately send data to each other, and the station receiving the data uses logic as the transmission data. The configuration is such that the value 1 is sent. Furthermore, we have set up an algorithm that shifts to a different station configuration when a specific pattern is detected in the logical product of communications between these two stations.

[Operation] Since the branch transmission system of the present invention is configured as described above,
The logical product of communication data between two stations other than the own station, which was previously only discarded, is received, and the pattern of this logical product is calculated in advance to expect the logical product of the bit pattern of inter-station control information. By comparing with the value table, it became possible to decode and utilize the communication content of the control information between the two stations at the third station connected via the branch connection device. In particular, if this mechanism is used to transmit configuration switching timing information, failure occurrence information, etc. that are commonly required for stations in the system, a new band for transmitting control information between stations will be required for each opposing station. Therefore, the line efficiency when using a branch connection device can be greatly improved. Furthermore, based on the specific AND button sent by this mechanism, it is possible to synchronously change the configuration at each station, and communication disturbances due to timing shifts can be prevented.

[Example] An example of the present invention will be described below with reference to FIGS. 1 and 3. FIG. 1 is an internal block diagram of the multiplexing device. Data input from the line is input to the demultiplexer 23 via the transmission line interface 30 under the control of the reception bit counter 22 and the address control memory 21, and is processed on a channel-by-channel basis. The transmitter performs the opposite process. Here, in the present invention, an analysis section 24 for logical product of control information between other stations is added. This block consists of an input data shift register 241, a logical product expected value table 242, and a logical product comparison section 243. The operation of this part will be explained below. FIG. 3 is a redrawing of FIG. 2 based on the gist of the present invention. In this figure, stations N1 and N2 are in time slot l-1, and station N1 is in time slot 2.
and N3 are communicating in time slot 3 with stations N1 and N4, respectively. If we pay attention to station N4, it communicates with station N1 using time slot 3, but in other time slots 1.2,
f”la is input. Here, it is assumed that a path for transmitting control information between stations between N1 and N2 is set at the beginning of the time slot, and for example, when the configuration is switched from N]- to N2. The designation and approval of the configuration switch from N2 to N1 are made through this route, with only one bit 0 in each FE (to
)) Suppose that they notify each other with continuous bangs. This bang is received in time slot 1 at N4 (and N3)
The first bit of this is theory 3!1! With a deviation determined by the transmission delay until the product is taken, only Nibit1- (or -Pippl~) appears as a continuous bang with O in the Hebit. At N4, this bit is extracted by the reception bit counter 22 as a communication bit between N1 and N2, this bit string is input to the shift register 241, and the bit slam appearing here is compared with the value of the AND expected value table 242 by the comparator 243. Use and compare. As a result of this comparison, upon seeing a match three times in a row, N4 assumes that the status of a configuration switching instruction has been received, and performs configuration switching according to predefined conditions. In this way, by setting the inter-station control information path only between N1 and N2, information such as configuration switching can be manually set for N3 and N4 at the same time. All of the time slots used by N4 for communication can be used as user data, which can improve usage efficiency. FIG. 4 is an example of an algorithm for communicating control information between two stations to enable direct decoding when a third station receives a logical product. In the inter-station control information path, data is sent only from the station that has the right to transmit data, and the other station is kept in a reception mode that continuously sends it I II buttons until the right to transmit data is obtained. As a result, the remaining stations having the control information logic analysis unit can also receive the transmitted information from the station holding the transmission right in a form that can be easily restored.

[Effects of the Invention] According to the present invention, the bandwidth for transmitting control information between stations in a network consisting of time division multiplexing devices connected to branching and connecting devices can be made equivalent to one pair, regardless of the number of stations in the network. Since the number of lines can be reduced, line usage efficiency can be improved and an economical network can be constructed. Furthermore, since changes in the configuration of the stations can be made synchronously at each station, the time during which transmission is unavailable due to configuration changes can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram of channel allocation in a network including branching and connecting devices, and FIG.
FIG. 4 is an explanatory diagram of channel allocation according to the present invention, and FIG. 4 is a flowchart of a process for transmitting control information between stations. Explanation of symbols N1 to N4...Time division multiplexing device, 1...Branch connection device, 24...Inter-office control information logical product analysis unit, 241.Shift register, 242... logical product expected value table, 243. ... Comparison match detection circuit.

Claims (1)

[Scope of Claims] 1. In a system in which three or more stations communicate digital multiplexed data via a branch connection device provided in the middle of the high-speed digital line via a high-speed digital line, two stations means for a third station not involved in the exchange of inter-station control information being carried out between the two stations to receive a logical product of transmitted and received signals between the two stations from the branch connection device, and to analyze the logical product; It is characterized by obtaining information about the situation between the two stations, and based on this information, changing the communication contents of the third station or the structure of the data to be transmitted, and performing maintenance and operation management of the system. A branch transmission method for multiplexed signals. 2. Branch transmission of a multiplexed signal according to claim 1, having an expected value table of the logical product as means for analyzing the received logical product, and means for comparing the received input signal with this table. method. 3. In claim 1, the inter-office communication information is always transmitted and received alternately, and when receiving the inter-office information, the transmission signal has a logical value of 1, and the third station receives the logical product information. A multiplexed signal branch transmission method that restores the communication content between the two stations from the logical product when the communication occurs. 4. Branching of a multiplexed signal in which the third station uses a specific pattern included in the logical product of communication information between the two stations obtained by the method according to claim 1 as a timing signal for changing the station configuration. Transmission method.