JPH10190703A - Time division multiplex method - Google Patents

Abstract

(57) [Summary] In a local wired communication device connected in a multipoint manner, a plurality of digitized data are multiplexed even at a low transmission rate, and simultaneous communication is performed between different communication devices. SOLUTION: A master device transmits a network synchronization signal 1,
After that, a transmission pause time 4 is secured in order to avoid collision due to transmission between the devices, and then burst data 2-1 obtained by compressing digital data from a previously permitted master device or slave device on the time axis is transmitted. , The transmission suspension time 4 is secured. Thereafter, burst data 2 is similarly set.
-1 to 2-n are transmitted. Finally, the master device or the slave device transmits a control signal 3 for securing the channels 2-1 to 2-n of the burst data by the master device or the slave device, and the transmission pause time 4 is similarly secured. The data synchronization signal 6 is added to the burst data 2-1 to 2-n.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time-division multiplexing method in a local wired communication device in which a plurality of pairs are connected as a transmission line and a plurality of multipoints are connected.

[0002]

2. Description of the Related Art Hitherto, a loop transmission path has been known as a topology of a method of periodically time-division multiplexing a plurality of data. Hereinafter, the transmission method will be described with reference to FIGS.

In FIG. 7, reference numeral 21 denotes a control node for generating a synchronization signal and managing time slots, and reference numerals 22 to 24 denote communication nodes having no function for generating a synchronization signal and managing time slots. The control node 21 and the communication nodes 22 to 24 are connected in a loop as shown in FIG.

In FIG. 6, reference numeral 14 denotes one of the multiplexed signals.
Reference numeral 11 denotes a frame, 11 denotes a frame synchronization signal for synchronizing the frame 14, 13-1 to 13-n denotes transmitted burst data, and 12 denotes burst data.
This is a time slot reservation channel for performing time slot management of data from 1 to 13-n.

[0005] As shown by an arrow in FIG.
It is received by the communication node 22 transmitted from the control node 21. The communication node 22 that has received the burst data 13-1 to 13-n based on the time slot reservation channel 12.
, Or multiplexes the data for transmission, and transmits the frame 14 to the communication node 23. Similarly, data is transmitted and received from the communication node 23 to the communication node 24 and the control node 21, and is transmitted from the control node 21 to the communication node 22 again.

As described above, for example, data can be periodically transmitted from the communication node 24 to the communication node 22 via the time slot of the burst data 13-2.

[0007]

FIG. 8 shows a frame transmission path when the above-mentioned conventional time division multiplex communication system is applied to a topology connected at multiple points. Hereinafter, description will be made with reference to FIG.

In FIG. 8, reference numeral 31 denotes the control node 21.
A master device having the same function as
Is a slave device having the same function as the communication nodes 22 to 24.

When the conventional time-division multiplexing method is applied to the multipoint topology shown in FIG. 8, when the master device 31 wishes to multiplex data, as shown by the arrow, the frame 14 connects one slave device to another. Transmission is not possible until the master device 31 returns to the master device. As described above, since the frame 14 makes a round from the master device 31 to the slave device 34, from the slave device 34 to the slave device 33, from the slave device 33 to the slave device 32, from the slave device 32 to the master device 31, the frame 14 has a delay time of one round. , A delay time corresponding to the sum of the delay times of the transmission paths passing between the respective devices occurs. Furthermore, in order to avoid collisions caused by transmissions of the respective devices, each device can transmit only after receiving all the frames 14. Therefore, at least the delay time required for the frame 14 to go around each device is (sum of the delay times of the transmission paths passing between the respective devices), and
(Time when each device takes in frame 14 once) × Sum of devices. In other words, as the number of devices increases, the delay time increases in proportion, and the transmission efficiency decreases.

In addition, in the conventional time division multiplex communication system, the time slot management channel 12 is further assigned to the time slot management channel 12 in addition to the case where the transmission rate of the transmission path is low and the data length of the time slot reservation channel 12 cannot be sufficiently secured. If it is desired to perform system control other than the above, communication between devices is established only after transmitting and receiving the time slot reservation channel 12 a plurality of times. However, since there is only one time slot reservation channel in the frame 14, the frame There is a problem that as the period of 14 becomes slower, the response speed until the communication between the devices is established becomes longer.

SUMMARY OF THE INVENTION The present invention solves such a conventional problem. A time-division multiplexing system which can improve the efficiency of use of a transmission line and can shorten the time required for establishing communication between devices with low clock accuracy. Intended to provide

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a network synchronization signal transmitted by the master device to synchronize the entire network at the head, and a master device which has been previously authorized. Or burst data in which the slave device sequentially transmits data of a fixed length, a control signal whose main purpose is to secure the channel of the burst data at the end by the master device or the slave device, and the network synchronization signal. A multiplexing format in which one cycle includes the plurality of burst data and a transmission stop time added to secure a time during which all devices stop transmission immediately after each of the control signals, further comprising the plurality of burst data; The data synchronization signal is added to the data and the control signal.

[0013] Thus, the use efficiency of the transmission path can be improved without being affected by the increase in the number of connected devices.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention has a master device and a slave device which are a plurality of intra-site wired communication devices which use a pair of transmission lines as a transmission line and are connected in a multipoint manner. In a time-division multiplexing method that is repeated at the same period, a network synchronization signal transmitted by the master device to perform synchronization of the entire network at the beginning and the master device or the slave device permitted in advance have a fixed length. Burst data for sequentially transmitting the data, a control signal whose main purpose is to secure the channel of the burst data by the master device or the slave device, the network synchronization signal, the plurality of burst data, and A multiplex format in which the transmission stop time added to secure the time during which all devices stop transmission immediately after each of the control signals is one cycle. Configure Tsu bets, which was further added to the data synchronization signal to said control signal in said plurality of the burst data, the master device and the slave device,
The berth and the data can be periodically transmitted directly to all the devices at a previously permitted timing, and the berth and the data can be periodically received directly from the target device, so that the use efficiency of the transmission path can be improved.

According to a second aspect of the present invention, a network synchronization signal and a transmission stop time are secured before all the second and subsequent burst data of the sequentially transmitted burst data,
A control signal shorter than the control signal and a transmission stop time are added after all of the burst data before the last burst data of the burst data, and the control signal is secured immediately after each burst data, This has the effect of shortening the period of the control signal. Therefore, the invention according to claim 3 of the present invention, which can shorten the time required for establishing communication between the devices with low clock accuracy, provides an uplink control signal transmitted by the slave device and a downlink control signal transmitted by the master device. A control signal is divided into control signals, and a transmission stop time is added between the uplink control signal and the downlink control signal.
This has the effect that it is secured every burst data cycle. Therefore, an embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

(Embodiment 1) FIG. 1 is an example of a wiring form (topology) showing a transmission path of burst data in an embodiment of the present invention. In the figure, reference numeral 41 denotes a master device which generates a reference clock of the system;
Slave devices 2 to 44 are synchronized by the clock of the master device 41. Each of the devices 41 to 44 constitutes a topology that is connected in a multipoint manner by a pair of pairs.

FIG. 2 shows a format of the time division multiplex communication system according to the first embodiment of the present invention. In FIG. 2, reference numeral 1 denotes a network synchronization signal transmitted from the master device;
Is a signal pause time 2-1 to 2-2-secured after transmission of the network synchronization signal 1 to avoid collision due to transmission between devices.
n is burst data transmitted by a previously permitted master device or slave device.
After transmission of 1 to 2-n, the transmission suspension time 4 is ensured similarly to the network synchronization signal 1.
Reference numeral 3 denotes each of the devices 4 after transmitting the burst data 2-n.
Any of the control signals 1 to 44 is a control signal to be transmitted, and the transmission suspension time 4 is ensured even after the transmission of the control signal 3, similarly to the network synchronization signal 1. Reference numeral 5 denotes a cycle in which the above multiplex format is defined as one cycle. Reference numeral 6 denotes the burst data 2-1 to 2-n and the control signal 3
Is a data synchronization signal for direct reception by a device other than the transmission device.

FIG. 3 is a block diagram for realizing the time division multiplex format of FIG.

In FIG. 3, reference numeral 51 denotes a reception demodulation unit for receiving multiplexed data on a pair line and demodulating the data into digital data; and 52, a unit for modulating data generated by the transmission data multiplexing unit and transmitting the data on the pair line. Is a transmission modulation unit. 5
Reference numeral 3 denotes a network synchronization clock generator for generating a master clock in the slave device from a network synchronization signal transmitted from the master device.
4 is added to the slave device side, a network synchronization detecting unit for detecting a network synchronization signal transmitted from the master device, 55 is added to the burst data 2-1 to 2-n and the control signal 3 A data synchronization signal detector for detecting the data synchronization signal. A time slot management unit 56 manages the timing of each data multiplexed on the transmission path, controls the reception burst data channel, and controls and controls the timing of various transmission data.
Is a reception data extraction unit for extracting target burst data, and 58 is a transmission data control unit for controlling transmission burst data and a control signal.

Reference numeral 59 denotes a network synchronization signal generator for generating the network synchronization signal 1, and reference numeral 60 denotes a data synchronization signal to be added when transmitting the burst data and the control signal. A data synchronization signal generation unit 61 for generating a transmission data multiplexing unit for multiplexing a network synchronization signal, a data synchronization signal, transmission burst data, and a control signal in accordance with the time slot management unit 56. The transmitted data is transmitted to the transmission modulation 52. A control unit 62 controls the entire apparatus, secures a burst data channel, generates control data for performing other system control, analyzes a received control signal, and controls a transmission / reception channel. .
63 is a receiving storage device for temporarily storing data such as voice received at a burst data interval and transmitting the data at a constant rate lower than the simultaneously received transmission rate, and 64 is data such as voice generated at a constant rate. Is a transmission storage device for temporarily storing data at a transmission rate higher than the transmission rate received at the same time at a burst data interval.

Next, the first embodiment configured as described above will be described by way of an example of bidirectional communication between the slave devices 42 and 43.

In FIG. 1, slave devices 42 to 44 are operated by a network synchronization signal 1 transmitted from a master device 41.
Are network synchronized. At the initial stage, the burst data 2-1 to 2-n that are sequentially secured thereafter are in an untransmitted state because no device is permitted. Next, the control signal 3 is transmitted from the master device to poll all of the slave devices, and one cycle 5 ends. Slave device 4
The control signals 2 to 44 transmit the control signal 3 at each cycle 5 and transmit request information to the master device.

Thus, the slave devices 42 to 4
4 repeats communication with the master device 41 and recognizes that the slave devices 42 and 43 respectively transmit and receive data via the master device. In addition, the slave device 42 recognizes the burst data 2-1 as a transmission channel and recognizes the burst data 2-2 as a reception channel. Similarly, the slave device 43 recognizes the burst data 2-2 as a transmission channel and recognizes the burst data 2-1 as a reception channel. Each slave device that has recognized the transmission / reception timing of the burst data mutually repeats transmission / reception at the timing of the burst data 2-1 and 2-2 based on the network synchronization signal.

Next, the signal processing of the time division multiplex system will be described. 3, in the master device 41, the time slot management unit 56 manages all of the multiplex formats based on its own master clock. The network synchronization signal 1 generated by the network synchronization signal generation unit 59 is transmitted by the transmission modulation unit 52 via the transmission data multiplexing unit 61. The slave devices 42 to 44 receive the network synchronization signal 1 at the reception demodulation unit 51 almost simultaneously. The network synchronization clock generator 53 generates a master clock in the slave device from the network synchronization signal. At the same time, a network synchronization signal is detected by the network synchronization signal detection unit 54. The time slot management unit 56 of the slave device manages the multiplex format based on the network synchronization detection signal and the master clock.

The transmission / reception of the control signal 3 is the same for all of the master device 41 and the slave devices 42 to 44. At the time of transmission, the control signal transmitted from the control portion 62 is added to the transmission data control portion 58 and the transmission data multiplexing portion. The data synchronizing signal 6 generated by the data synchronizing signal generating unit 60 is added via the unit 61 and transmitted on the pair line by the transmission modulating unit 52. Conversely, at the time of reception, the reception timing is detected by the data synchronization signal detection unit 55 from the signal received by the reception modulation unit 51, and the control signal is separated by the reception data extraction unit 57 based on the time slot management unit 56. 62.

The communication between the slaves 42 and 43 is established by the control signals transmitted and received as described above, and the burst data 2-1 and 2-2 are transmitted and received. 63, transmission storage device 64
Other than that is the same. What is different is the transmission timing and the data length.

With the above configuration, the slave device 4
The burst data 2 and 43 can perform bidirectional communication directly without using other devices by using the burst data 2-1 and 2-2.

(Embodiment 2) FIG. 4 shows a format of a time division multiplex system according to Embodiment 2 of the present invention, which is multiplexed into the topology shown in FIG.

In FIG. 4, reference numeral 71 denotes a network synchronization signal transmitted from the master device, and reference numeral 72 denotes a transmission suspension time secured after transmission of the network synchronization signal 71 to avoid collision between devices due to transmission. is there. Reference numeral 73-1 denotes burst data transmitted by a previously permitted master device or slave device. After the transmission of the burst data 73-1, a transmission suspension time 72 is secured in the same manner as the network synchronization signal 71. It has a configuration. Reference numeral 74 denotes a control signal transmitted by any of the devices 41 to 44 after the transmission pause time 72 after the transmission of the burst data 73-1.
After the transmission of the control signal 74, the transmission suspension time 72 is ensured similarly to the network synchronization signal 71. Reference numeral 78 denotes a format cycle having the above as one cycle. Further, the format period 78 is the number n of burst data multiplexed.
And a data cycle 75 is formed. Further, the burst data 73-1 to 73-n and the control signal 74
As in the first embodiment of the present invention, a data synchronization signal for direct reception by a device other than the transmitting device is added to.

A block diagram for realizing the time-division multiplexing format shown in FIG. 4 has the same configuration as the block diagram shown in FIG.

Next, the second embodiment configured as described above will be described with reference to an example of bidirectional communication between the slave devices 42 and 43.

In FIG. 1, the slave devices 42 to 44
Are network synchronized by the network synchronization signal 71 shown in FIG. Where format period 7
Burst data 73-1 to 7 secured every 8
3-n is in an untransmitted state until communication is established. Next, a control signal 74 is transmitted from the master device to poll all of the slave devices.
8 ends. Each of the slave devices 42 to 44 transmits a control signal 74 at each format cycle 78 and transmits request information to the master device.

In this manner, the slave devices 42 to 44 repeat communication with the master device 41, and recognize that the slave devices 42 and 43 respectively transmit and receive data via the master device. In addition, the slave device 42 recognizes the burst data 73-1 as a transmission channel and recognizes the burst data 73-2 as a reception channel. Similarly, the slave device 43 recognizes the burst data 73-2 as a transmission channel and recognizes the burst data 73-1 as a reception channel. The respective slave devices that have recognized the transmission / reception timing of the burst data from each other transmit burst data 73-1 and 73-2 following the network synchronization signal, respectively.
Transmission and reception are repeated at the timing of.

The time-division multiplexing signal processing is the same as in FIG. The difference is that the time slots managed by the time slot management unit 56 are configured as shown in FIG.

With the above configuration, the data length of the control signal 74 is shorter than the control signal 3 shown in FIG. 2 of the first embodiment of the present invention, but the period of the control signal can be shortened.

(Embodiment 3) FIG. 5 shows a format of a time division multiplexing system according to Embodiment 3 of the present invention, which is multiplexed on the topology shown in FIG.

FIG. 5 differs from FIG. 4 only in the portion of the control signal 74 in FIG. 4, and the other points are completely the same. That is, the difference is that the data length of the control signal 74 in FIG. 4 is changed to that in FIG. 5 so that the transmission pause time 72 is further secured between the control signals 76 and 77. Control signal 76
Is an uplink control signal for any one of the slave devices 42 to 44 to transmit to the master device 41.
Reference numeral 7 denotes a downlink control signal transmitted from the master device 41 to the slave device. As in Embodiment 1 of the present invention, a data synchronization signal for direct reception by a device other than the transmitting device is added to uplink control signal 76 and downlink control signal 77.

A block diagram for realizing the time-division multiplexing format shown in FIG. 5 is configured similarly to the block diagram shown in FIG.

Next, the third embodiment configured as described above will be described by way of an example of bidirectional communication between the slave devices 42 and 43.

In FIG. 1, slave devices 42 to 44
Are network-synchronized by the network synchronization signal 71 shown in FIG. Where format period 7
Burst data 73-1 to 7 secured every 8
3-n is in an untransmitted state until communication is established. The uplink control signal 76 is also in a non-transmission state until a transmission request is received from the master device. Next, a down control signal 77 is transmitted from the master device to poll all of the slave devices, and one format cycle 78 ends.
The slave devices 42 to 44 transmit the uplink control signal 76 at each format cycle 78 and transmit request information to the master device. While receiving the uplink control signal 76 from each slave device, the master device 41 sequentially transmits the next response to each device as a downlink control signal.

In this manner, the slave devices 42 to 44
Repeats communication with the master device 41, and recognizes that the slave devices 42 and 43 respectively transmit and receive data via the master device. In addition, the slave device 42 recognizes the burst data 73-1 as a transmission channel and recognizes the burst data 73-2 as a reception channel. Similarly, the slave device 43 recognizes the burst data 73-2 as a transmission channel and recognizes the burst data 73-1 as a reception channel. Each slave device that has recognized the transmission / reception timing of the burst data from each other transmits the burst data 73-1 and 73-73 following the network synchronization signal, respectively.
Transmission and reception are repeated at the timing of 2.

The time-division multiplexing signal processing is the same as in FIG. The difference is that the control signal is divided into uplink and downlink in the time slot managed by the time slot management unit 56, as shown in FIG.

With the above configuration, the data lengths of the uplink control signal 76 transmitted by the slave device and the downlink control signal 77 transmitted by the master device are respectively based on the control signal 74 of the second embodiment of the present invention shown in FIG. However, the period of the control signal can be further shortened.

In the above embodiment, three slave devices have been described as an example. The present invention is not limited to this,
A number of three or more is also possible. Also, although hardware has been described as an example of a means for realizing the present invention, processing by software is also possible. Also, the bidirectional communication between slave devices has been described as an example, but communication between a master device and a slave device, simultaneous transmission from one device to a plurality of other devices, and the like are also possible.

[0045]

As described above, according to the present invention, the master device and the slave device can periodically transmit burst data directly to all devices at a previously permitted timing, and can directly transmit burst data from the intended device. Since data can be received periodically, transmission and reception of continuous data such as voice can be naturally performed, and transmission delay caused by the burst data transmitted by itself circulating through all devices, that is, (each device Sum of delay time of transmission path passing between
And the delay time of the sum of the number of devices (the time taken by each device to capture the entire frame) can be avoided, so that the use efficiency of the transmission path can be maintained high without being affected by the increase in the number of connected devices. The effect that it can be obtained is obtained.

According to the present invention, the control signal is always allocated after the burst data, so that the data length of each control signal is shortened, but the cycle of the control signal is shortened, and the response speed of the system is increased. It has the effect of. In addition, by always assigning the network synchronization signal before the burst data, the format becomes one cycle, which simplifies the time slot management and shortens the free-running time of the clock generated by the network synchronization signal. ,
The effect that an oscillator with low accuracy can be used is obtained.

Further, according to the present invention, by dividing the control signal into an uplink control signal and a downlink control signal, the communication interval between the master device and the slave device is shortened, and the response speed is further increased. In addition, since the slave device can exclusively use the uplink control signal and the master device can use the downlink control signal exclusively, there is no need to perform collision avoidance control of the control signal between the master device and the slave device, so that the slave device can easily transmit and receive. .

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a transmission path of burst data when a time division multiplexing method according to an embodiment of the present invention has a multipoint connection topology.

FIG. 2 is a format of a time division multiplex communication system according to the first embodiment of the present invention.

FIG. 3 is a schematic block diagram of signal processing of a time division multiplex system according to the embodiment of the present invention.

FIG. 4 is a format of a time division multiplex communication system according to a second embodiment of the present invention.

FIG. 5 is a diagram illustrating a format of a time division multiplex communication system according to a third embodiment of the present invention.

FIG. 6 shows a conventional time-division multiplex format using a loop transmission path as a topology.

FIG. 7 is a diagram showing a wiring configuration in which a conventional loop transmission path is used as a topology.

FIG. 8 shows a frame transmission path when a time-division multiplexing method used for a conventional loop transmission path is changed to a multipoint connection topology.

[Explanation of symbols]

 Reference Signs List 1 network synchronization signal 2 burst data 3 control signal 4 transmission pause time 5 cycle 6 data synchronization signal 41 master device 42 to 43 slave device 51 reception demodulation unit 52 transmission modulation unit 53 network synchronization clock generation unit 54 network synchronization signal detection unit 55 data Synchronization signal detection unit 56 Time slot management unit 57 Received data extraction unit 58 Transmission data control unit 59 Network synchronization signal generation unit 60 Data synchronization signal generation unit 61 Transmission data multiplexing unit 62 Control unit 63 Reception storage device 64 Transmission storage device 71 Network synchronization Signal 72 Transmission pause time 73-1 to 73-n Burst data 74 Control signal 75 Data period 76 Up control signal 77 Down control signal 78 Format period

Claims (3)

[Claims] 1. A time-division multiplexing method in which a pair of transmission lines is used as a transmission path, has a master device and a slave device, which are a plurality of local wired communication devices connected in a multipoint manner, and is repeated in the same cycle. A network synchronization signal transmitted by the master device to synchronize the entire network, burst data that the master device or the slave device permitted in advance sequentially transmits data of a fixed length, and All the devices stop transmitting immediately after each of the control signal whose main purpose is to secure a channel of burst data by the master device or the slave device, the network synchronization signal, the plurality of burst data, and the control signal. And a transmission stop time added in order to secure a time period for the transmission, and a multiplex format having one cycle. Time division multiplexing method, characterized in that the addition data synchronization signal and the over data to the control signal within. 2. The burst data 2 which is sequentially transmitted.
A network synchronization signal and a transmission stop time are secured before all burst data after the first burst data, and a control signal shorter than the control signal is transmitted after all burst data before the last burst data of the burst data. 2. The time division multiplexing method according to claim 1, wherein a stop time is added. 3. Dividing the control signal into an uplink control signal transmitted by a slave device and a downlink control signal transmitted by a master device, and adding a transmission stop time between the uplink control signal and the downlink control signal. 3. The time-division multiplexing method according to claim 2, wherein: