JPS63237636A - Concentration/distibution system - Google Patents

Abstract

PURPOSE:To simplify control system and to execute the concurrent processing of plural controls by providing plural time slots for system control and those for information communication in the frame of information signals transmitted through a transmission line. CONSTITUTION:The frame of a signal transmitted through transmission lines 3, 4 between a central unit 1 and plural concentration/distribution terminals 2 is constituted of plural voice data channels and the plural channels for system control that are set by time division similarly. A control signal ASG and a response signal RSP are multiplexed with time division, and formed in plural channels. As to the plural voice data channels, a window period necessary for the measurement of delay time due to polling is estimated, and plural time slots are set from the end of its one frame. As a result, the polling for the delay time measurement and the contention for call setting control can be executed simultaneously.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention connects a plurality of terminal devices to a central device via concentrating and distributing terminals placed at various locations, and controls the system. This invention relates to a line concentration and distribution system that allows for efficient operation.

(Conventional technology) Multiple terminal devices such as telephones are connected to a private branch exchange (PBX).
When configuring a network by connecting each terminal device to the private branch exchange (PBX), it takes a lot of effort to directly connect each terminal device to the private branch exchange (PBX), and the equipment costs are also large. That is, in most cases, these terminal devices are generally distributed and arranged in a plurality of buildings or on a plurality of floors even in the same building. Therefore, installing individual signal cables between these distributed terminal devices and private branch exchanges (PBXs) involves large-scale construction work and requires enormous equipment costs.

Therefore, as shown in FIG. 3, for example, line concentration and distribution terminals 2a and 2b are provided for each of a plurality of buildings or for each different floor.

~2n are provided, and these line concentration distribution terminals 2a, 2b, ~
2n and the central equipment 1 including the private branch exchange (PBX)
and the signal cable (first transmission line 3 and second transmission line 4)
Connect via. It is considered that the terminal device 5 is connected to the central device 1 via the line concentration and distribution terminal 2 by connecting the terminal device 5 to the line concentration and distribution terminal 2 closest to its installation location.

Such a system configuration not only facilitates the installation of signal cables between the core central unit 1 and the plurality of concentration distribution terminals 2, but also allows the terminal equipment 5 to be connected to the nearest concentration distribution distribution terminal. Since it is only necessary to connect to 2, it is possible to flexibly construct a network.

In the system configured as described above, signals are transmitted in a time-sharing manner between the plurality of line concentration distribution terminals 2 and the central unit 1 via the common transmission paths 3 and 4 as described below. is now being carried out.

That is, the central device 1 transmits transmission data Do 1L1 to each concentration distribution terminal 2a, 2b, to 2n via the second transmission line 4, for example, in a frame structure as shown in FIG. 4(a).
1 , Do 12,12 , . . . Do In, In are transmitted in a time-division manner with dummy data indicated by diagonal lines in the diagram interposed therebetween. Here, the subscript 1x attached to each data Do indicates the address of the line concentration distribution terminal, and! X indicates the transmission data. In addition, the ASG runs from the central device 1 to each concentration distribution terminal 2a,
2b, to 2n are control signals. This control signal AS
G is composed of mode information indicating the control mode, address information specifying the east line distribution terminal, and control information given to the specified line concentration distribution terminal. A like this
One frame of the downlink transmission path is constructed by adding a predetermined window frame to the SG signal and the above transmission data.

On the other hand, each of the line concentration distribution terminals 2a, 2b, to 2n transmits transmission data DI, Dl to the central device 1 via the first upstream transmission line 3, for example, in a frame configuration as shown in FIG. 4(b). ll, 11 12. +2' ~DIIn
, In are transmitted in a time-division manner. One frame of the uplink transmission path is constructed by adding a predetermined window frame to these transmission data. R transmitted in this wind frame
8P is a response signal transmitted by the designated concentrating and distributing terminal in response to the ASG signal for purposes such as measuring transmission delay time, which will be described later.

By the way, each of the line concentration and distribution terminals 2 is connected to a different position on the transmission line 3.4. For this reason, the transmission path length between each concentration distribution terminal 2 and the central device 1 is different for each concentration distribution terminal 2, and due to the difference in transmission path length, the transmission path length between each concentration distribution terminal 2 and the central device 1 is different. It is undeniable that there will be a difference in the signal transmission time of the signals transmitted between the two. Therefore, if signal transmission is performed without considering the difference in transmission delay time, time slots are allocated in a time-division manner as described above, and the signal is transmitted between each concentrator and distribution terminal 2 and the central equipment 1. A problem occurs when the two devices collide on the transmission path.

Therefore, the present inventors measured the transmission delay time in signal transmission between each concentration distribution terminal 2 and the central equipment 1 using the above-mentioned ASG and R3P in Japanese Patent Application No. 59-268824. proposed controlling the transmission timing of signals transmitted from each line concentration distribution terminal 2 to the central unit 1 based on the measurement results, thereby avoiding signal collisions on the transmission path.

This method basically switches the ASG signal between a call control mode and a delay time measurement mode,
First, the mode of the ASG signal is set to a mode for measuring delay time. and ■ From the central device 1 to a plurality of line concentration and distribution terminals 2 (2) a signal As for sequentially specifying the line concentration and distribution terminals is sent.
Send G.

■ The line concentrator and distribution terminal 2 that received this designation utilizes the above-mentioned window frame period to
A predetermined response signal RSP is transmitted to the central device 1, and the response signal RSP returned from the central device 1 is received.

(2) The time from transmission to reception of the response signal RSP is measured as the transmission delay time between the line concentration distribution terminal 2 and the central device 1.

(2) Based on this transmission delay time, the transmission timing of the signal transmitted from the line concentration/distribution terminal 2 to the central unit 1 is adjusted and controlled.

However, when measuring the delay time in this way, when a response signal R3P is sent from the line concentration distribution terminal in a given frame, the central device returns the response signal R3P to the line concentration distribution terminal in the next frame. Therefore, since there is an empty frame in the frame in which the line concentration distribution terminal sent the response signal R6P, the central unit uses this frame to transmit the control signal ASG for call control.

Specifically, in synchronization with the frame period shown in Fig. 1(a), polling P is used to measure the delay time for each frame as shown in Fig. 1(b), and polling P is used to perform call control. Contention C is repeated alternately.

By alternately switching between the polling P and contention C modes, the control signal ASG and response signal RSP prepared for each frame are effectively used to efficiently measure the delay time and control the call setup. It is something that should be done.

However, when the control mode in the central device is switched between polling P and contention C for each frame in this way, a problem arises in that the processing load on the central device becomes complicated.

Moreover, call control based on contention C may be concentrated in a short period of time as traffic increases. On the other hand,
Delay time measurement by polling P depends on the number of line concentration distribution terminals participating in the system. For this reason, there is a risk that simply switching the control mode alternately every frame as described above will not be able to adequately cope with call control during high traffic.

(Problems to be Solved by the Invention) As described above, in the line concentration distribution method proposed earlier by the present inventors, the contention C mode and the polling P mode are alternately switched every frame. Therefore, there are problems in that the time required for call setup is too long and that the switching control becomes complicated.

The present invention was made in order to solve the above-mentioned problems through subsequent research and development, and its purpose is to shorten the time required for call control and to simplify control over polling and feedback. The purpose of the present invention is to provide a line concentration distribution system that can achieve the following objectives.

[Configuration of the Invention □ (Means for Solving the Problems) The present invention provides a method for time-divisionally transmitting signals to a central device and a plurality of line distribution terminals via first and second transmission paths. In the line concentration and distribution method, the signal transmission delay time in the first and second transmission paths is measured, and the signal transmission timing from each of the line concentration and distribution terminals is controlled based on the measurement results. The present invention is characterized in that a plurality of time slots for information communication and a plurality of time slots for system control are provided in a frame of a signal in which information is transmitted via a transmission path.

And the time slots for controlling the multiple systems mentioned above,
The present invention is characterized in that it is used for at least delay time measurement by polling and call setting control by contention, and also used for plural call setting controls by contention.

(Function) According to the present invention, a plurality of time slots for information communication and a plurality of time slots for system control are time-division multiplexed in a frame of a signal that transmits information via the first and second transmission paths. Since the plurality of time slots for system control are provided, delay time measurement by polling and call setting control by contention can be performed simultaneously using the plurality of time slots for system control. As a result, there is no need to alternately switch the control mode between contention and polling as in the past, and the control can be greatly simplified. In addition, since it is possible to simultaneously perform multiple call setup controls based on contention using multiple system control time slots, it is possible to effectively deal with increases in traffic, and to reduce traffic in a short time. It becomes possible to efficiently control multiple call settings.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows the form of a control signal transmission mode according to an embodiment of the present invention in comparison with the form of the previously proposed control signal transmission mode, and FIG. 2 shows an example of the structure of the signal frame. It is a diagram.

The feature of this method is that the frame structure of the signal transmitted via the transmission lines 3 and 4 between the central equipment l and the plurality of line concentration distribution terminals 2 is set in a time-division manner as described above. The main feature of this system is that it has a plurality of audio data channels, and a plurality of system control channels, which are similarly set in a time-sharing manner.

That is, the above-mentioned control signal ASG and response signal RSP are each time-division multiplexed to form a plurality of channels.

Then, one of the plurality of system control channels is used to measure the delay time by polling as described above, and another one is used to perform the call setting control by contention as described above.

If there are more system control channels, the system control channels may be used in parallel for contention-based call setup control in order to cope with increased call setup traffic.

Specifically, FIG. 2 shows the control signal ASG and its response signal R.
A plurality of system control channels for connection and one system control channel for polling may be set to indicate the relationship with the SP.

For a plurality of audio data channels, a plurality of time slots may be set from the end of one frame in consideration of the window period necessary for measuring the delay time by polling as described above.

In this system where the protocol is defined in this way, for example, as shown in FIG. It becomes possible to do so.

Focusing on the confirmation response procedure, if the central equipment simultaneously specifies polling for delay time measurement and contention for call setup control in the first frame, the specified line distribution terminal returns the response in the next frame. The central device will then further confirm the response in the next frame.

In other words, control for delay time measurement using ASG and R3P and control for call setting control are performed simultaneously, and information communication between the central equipment and the line concentration distribution terminal for these controls is performed every other frame. It will be done.

Therefore, it is possible to perform another polling and contention at the same time by using this every other empty frame.

Therefore, in the central device, there is no need to alternately switch its control mode for each frame as in the past, and the control system can be significantly simplified. Further, as described above, since it is possible to control another line concentration distribution terminal in parallel for each frame, it is possible to increase the amount of control.

As a result, even if call setup requests are concentrated in a short period of time, it is possible to promptly deal with the requests. In particular, as shown in Figure 2, if call setup control based on contention is performed simultaneously on multiple concentrator and distribution terminals in parallel using multiple system management channels, even more call setup requests can be made. It becomes possible to deal with the situation effectively.

If you want to take a lot of processing time for call setup control, for example, as shown in Figure 1(d), while sending and receiving signals for delay time measurement by polling every frame, The signal transmission and reception for call setup control may be performed every two frames.

In this way, it becomes possible to process twice as many functions in parallel as compared to the method shown in FIG. 1(C). Furthermore, it is possible to double the processing time for each contention, thereby providing processing margin. In other words, it becomes possible to gain processing time after receiving the signal at the central unit and the line concentration/distribution terminal.

Regarding polling, for example, as shown in FIG. 1(e), control signals may be transmitted and received every two frames, similar to contention.

As explained above, in this system, multiple channels for system control are provided in a system in which information is transmitted by sharing a transmission path in a time-sharing manner between a central device and multiple line concentration distribution terminals. Therefore, these system control channels can be used to simultaneously perform control for delay time measurement by polling and control for call setup by contention. Therefore, unlike the conventionally proposed system, there is no need to switch between polling and contention modes each time, and the control can be greatly simplified. In other words, the number of operating modes of the system can be reduced, and the control system can be simplified.

Also, you can use the empty frame to process other polling and contention in parallel.
The amount of processing can be increased. For example, it is possible to perform call processing using one frame and simultaneously proceed with call processing using the other frame.

Furthermore, it becomes possible to use a plurality of system control channels for a plurality of pollings and contentions, making it possible to increase the number of systems controlled.

As a result, it becomes possible to perform efficient call setting control in a short time and to construct a system that can adequately handle high traffic.

Note that the present invention is not limited to the embodiments described above. For example, the number of audio data channels and the number of system control channels set in one frame may be determined according to the system specifications. Furthermore, the number of line concentration and distribution terminals connected to the system is not particularly limited.

Also, which of the multiple system control channels will be used for polling and which will be used for contention, and whether the information exchange cycle will be one frame or two frames, etc. It may be determined according to the system specifications. In short, the present invention can be implemented with various modifications without departing from the gist thereof.

[Effects of the Invention] As explained above, according to the present invention, it is possible to simplify the control system by reducing the number of operation modes of the system, and it is also possible to process multiple controls in parallel. .

As a result, great practical effects can be achieved, such as making it possible to quickly and effectively process call setup requests that are concentrated in a short period of time.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the concept of a method according to an embodiment of the present invention in comparison with the previously proposed method, and FIG. 2 is a diagram illustrating an example of a frame structure of a signal transmitted using a method according to an embodiment of the present invention. , FIG. 3 is a schematic configuration diagram of the line concentration and distribution system, and FIG. 4 is a diagram showing the basic frame structure of signals transmitted and received between the central equipment and a plurality of line concentration and distribution terminals. 1... Central device, 2a, 2b, ~2n... Line concentration distribution terminal, 3.4... Transmission line, 5... Terminal equipment.

Claims (3)

[Claims] (1) Time-divisionally transmitting signals from a plurality of line concentration distribution terminals to a central device via a first transmission path, and time-sharing signals from the central device to the plurality of line concentration and distribution terminals via a second transmission path. When transmitting signals in divisions, the signal transmission delay time on the first and second transmission paths is measured, and the signal transmission timing from each of the line concentration and distribution terminals is controlled based on the measurement results. The frame of the signal that transmits information via the first and second transmission paths includes a plurality of time slots for information communication and a plurality of time slots for system control. A line concentration distribution method. (2) The line concentration distribution system according to claim 1, wherein the plurality of system control time slots are used respectively for at least delay time measurement based on contention and call setting control based on polling. (3) The line concentration distribution system according to claim 1, wherein the plurality of system control time slots are respectively used for plural call setting controls by polling.