JP2716379B2 - Concentrator-type TDMA system in optical branching transmission system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical branching transmission system in which a master station and a plurality of slave stations are connected via an optical splitter. The present invention relates to an optical branching transmission system in a case where it is necessary to connect all terminals to a transmission system via a slave station when exceeding this.

[0002]

2. Description of the Related Art In a conventional optical branching transmission system,
In the transmission system configuration as shown in FIG.
Are assigned to transmission line time slots.

[0003] In other words, the I.S. 4
Regardless of whether the ISDN terminal 4 having 30 interfaces has a call, a call time slot (2B + D data 14) between the master station 1 and each slave station 3 is secured.

FIG. 5 shows a frame configuration in the conventional optical branch transmission system described above. Each frame is allocated to each slave station, and a control data 11 is secured at the head, and a portion for inserting 2B + D data is secured thereafter. Regarding these frames, frames of the same length are secured uniformly regardless of the transmission state.

[0005]

In this conventional system,
Since the transmission line time slot is assigned to each slave station 3, that is, each ISDN terminal 4, the time slot is occupied irrespective of the presence or absence of a call, and the efficiency of transmission resources, that is, transmission capacity and transmission equipment is inefficient. is there.

An object of the present invention is to provide an optical branching transmission system that can effectively utilize transmission resources in view of the above-mentioned drawbacks.

[0007]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned disadvantages, a concentrator TDMA in an optical branching transmission system according to the present invention.
In the system, a terminal device for inputting / outputting data to / from the outside, a control unit for determining the presence / absence of the data and transmitting a call state control signal, and converting an electric signal including the call state control signal into an optical signal A plurality of slave stations including a slave station interface unit including an optical transmission unit for transmitting and transmitting, and a master station interface unit including an optical reception unit for reconverting an optical signal including the calling state control signal into an electric signal. A master station including a switching unit for controlling data connection of each terminal device according to a state of the calling state control signal from each of the slave stations; an input unit and at least a branch of at least the number of the slave stations; A first optical fiber transmission line that connects the master station and the input section of the optical branching section, and a second section that connects each of the branching sections of the optical branching section and each of the slave stations. Optical transmission system with two optical fiber transmission lines A kick concentrator type TDMA system,
Each of the slave stations includes means for transmitting the transmission capacity of the time slot allocation required by the slave station together with the calling state control signal, and the master station receives the transmission capacity control signal from each of the slave stations according to the calling state control signal. A TDMA control unit is provided for monitoring an available transmission capacity and allocating a time slot so that no free time is generated between the time slots of the slave stations.

[0008]

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the configuration of the optical branching transmission system according to the present invention, and the same parts as those in FIG. 4 are denoted by the same reference numerals. In the figure, the concentrator TDMA in the optical branching transmission system according to one embodiment of the present invention is IT-based.
U Recommendation I. ISDN terminal 4 having a 430 interface and slave station 3 for accommodating this terminal 4 in a network
And the master station 1 accommodating each slave station 3, and each slave station 3 and the master station 1 are connected by an optical fiber cable 5 via an optical splitter 2.

Here, the slave station 1 includes an optical transmission unit 8 for converting an electric signal into an optical signal and transmitting the signal, and a transmission line interface unit 8 having an optical receiving unit for receiving the optical signal and converting the signal into an electric signal. It includes a terminal 4, an I-interface unit 9 for performing an interface, and a control unit 10. Slave station 1
The control unit 10 determines the state of the call originating from the ISDN terminal 4 of the own station.
, And sends a signal for requesting the master station 1 to allocate a time slot from the control unit 10 to the interface unit 8.

On the other hand, the master station 1 has a transmission line interface unit 8 having the same function as the slave station 3, and checks the free space of the transmission capacity and manages each time slot in response to the time slot allocation request from the slave station 3. A TDMA control unit 7 for performing
An exchange unit 6 for connecting data signals of each ISDN terminal 4 is provided.

The operation of each of the above components will be described in detail with reference to the frame configuration shown in FIG. 2 and the sequence shown in FIG.

Assuming that the ISDN terminals 4 are all closed and in a non-communication state, the master station 1 and each slave station 3 manage each slave station 3 as shown in the frame configuration of FIG. Is assigned to the transmission line time slot. This control data includes a call state flag 12 together with data for managing the operation state of the slave station.
It is constituted by.

Here, when a call is made from a certain ISDN terminal 4, a data signal from the terminal 4 is transmitted according to the I.D. 430 I
The state changes to NFO1. The control unit 10 in the slave station 3 detects the state of the INFO1 and changes the calling state flag 12 from 0 to 1 for the master station 1 to thereby generate 144 kb.
/ S (2B + D) time slot allocation request is made.

This allocation request is detected by the TDMA control unit 7 in the master station 1, and determines whether the transmission capacity is empty. Based on the result of the determination, the assignable flag 13
Is changed from 0 to 1 and 144 kb / s (2B
+ D) time slots (2B + D data 14) are inserted.

On the other hand, in the slave station 3, the assignable flag 13 is detected by the control unit 10, a transmission time slot for the master station 1 is inserted by 144 kb / s (2B + D data: 14 minutes), and INFO1 is transmitted.

Until the subsequent call establishment, the exchange unit 6 and the IS
I. between the DN terminals 4 430 The same procedure as layer 1 is adopted.

By adopting such a system, frame allocation is conventionally uniformly performed for each slave station, and transmission resources are not always effectively used. Since the allocation can be performed, the transmission resources can be effectively used without any empty frames.

[0019]

As described above, by detecting the calling state of the ISDN terminal, it becomes possible to allocate the transmission line time slot, and the transmission resources can be used effectively.

[Brief description of the drawings]

FIG. 1 shows a concentrator T in an optical branching transmission system according to the present invention.
FIG. 2 is a configuration diagram illustrating an example of a DMA system.

FIG. 2 shows a concentrator T in the optical branch transmission system of the present invention.
FIG. 2 is a diagram illustrating a frame configuration of an embodiment of a DMA system.

FIG. 3 shows a concentrator T in the optical branch transmission system of the present invention.
FIG. 3 is a diagram showing a sequence of an embodiment of a DMA system.

FIG. 4 shows a concentrator TD in a conventional optical branching transmission system.
FIG. 2 is a configuration diagram illustrating an example of an MA system.

FIG. 5 shows a concentrator T in a conventional optical branch transmission system.
FIG. 2 is a diagram illustrating a frame configuration of an embodiment of a DMA system.

[Explanation of symbols]

 Reference Signs List 1 master station 2 optical branching device 3 slave station 4 ISDN terminal 5 optical fiber 6 switching unit 7 TDMA control unit 8 transmission line interface unit 9 I interface unit 10 control unit 11 control data 12 calling state flag 13 assignable flag 14 2B + D data

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hikaru Yasuda 1st Higashi-Shinmachi, Higashi-ku, Nagoya, Aichi Prefecture Inside Chubu Electric Power Co., Inc. (56) References JP-A-5-292108 (JP, A) JP-A-56-132093 (JP, A) JP-A-5-300166 (JP, A) JP-A-4-150634 (JP, A) Kaihei 2-94932 (JP, A) Electronic Information and Communication Handbook Volume 2 Volume 33 Data Communication Division 1 Data Transmission System 1. Basics of Data Transmission PP 2497 CCITT BLUE BOOK V OLUME. III FASCICLE III. 8.9 INTEGRATE D SERVICE DIGITAL NETWORK (ISDN) 430 IEICE Technical Report (IEICE Technical Report, Vol. 95, No. 532) IN95-105 pp. 41-48 Atsushi Otokawa et al., "Research on Customer Information Network"

Claims (1)

(57) [Claims] 1. A terminal device for inputting and outputting data to and from an external device.
And transmitting a call state control signal by determining the presence or absence of the data.
And a control unit for outputting the call state control signal.
A slave station interface including an optical transmitter for converting
A plurality of slave stations each having a face unit; and the calling state control.
Includes an optical receiver that reconverts optical signals containing signals into electrical signals.
A master station interface unit and the outgoing call from each of the slave stations.
Data connection of each terminal device according to the state of the state control signal
A master station having an exchange unit for controlling the
Optical branching device having at least branching units equal to or greater than the number of the slave stations
And a second connecting the master station and the input section of the optical branching section.
1 optical fiber transmission line, and each of said branch portions of said optical branch portion
And a second optical fiber transmission line for connecting the slave stations.
Concentration type TDMA system in optical branch transmission system
Each of the slave stations has a time slot
The transmission capacity of the assigned call is transmitted together with the call state control signal.
Means for issuing a call from the slave station.
Monitoring the free capacity of the transmission capacity by the status control signal
Therefore, there is no space between the time slots of the slave stations.
A TDMA control unit that allocates time slots
Optical branching transmission system characterized by having
Concentrator TDMA system.