JPS63272136A - Time division multiplex multiple access communication system - Google Patents

Abstract

PURPOSE:To attain the satisfactory call even at the time of a very bad cable transmission line by commanding a carrier and a time slot to be used to a time division multiplex multiple access TDMA terminal station in which an outgoing call or an incoming call occurs through a time slot for control when the outgoing call and the incoming call occur and executing the call connection. CONSTITUTION:A control station 1 sends a time slot for control through a sertain special TDMA base station through a distribution synthesizing device 3 and a coaxial cable 4 to all TDMA terminal stations 51-5m. For these all TDMA terminal stations 51-5m, by receiving the control signal of the time slot for the control, the carrier of a TDMA base station to be used in TDMA base stations 21-2n and a time slot for calling to be used in a time slot for calling transmitted by the carrier are designated. Thus, an equalizer is eliminated and the number of terminal stations capable of accommodation can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a time division multiple access (TDMA) communication system, and particularly to a communication system using carrier waves.

[Conventional technology]

Conventionally, this type of time division multiplex multiple access communication system has a control station,
It consists of a TDMA base station and a large number of TDMA terminal stations. The following method has been proposed as a countermeasure against an increase in the number of TDMA terminal stations in this system.

That is, the first method is to increase the signal transmission rate by carrier wave between the TDMA base station and the TDMA terminal station so as to accommodate the maximum number of TDMA terminal stations that can be expected in the future.

The second method is a method in which when the number of terminal stations increases exceeds a certain value, another system is added to cope with the increase.

[Problem that the invention seeks to solve]

However, in the first method, the rate of deterioration of the digital signal depends on the transmission characteristics (amplitude characteristics and 1 group delay characteristics) of the transmission path between the TDMA base station and a large number of TDMA terminal stations. There is a problem that the signal becomes large, and in extreme cases, it becomes impossible to transmit the signal. To avoid this, an equalizer that compensates for the transmission characteristics of the transmission path is required. However, TDM A
If the transmission characteristics up to the terminal station are different, equalizers corresponding to each characteristic or adaptive equalizers are required, which increases the cost of the entire system (problems arise).

Furthermore, in the second method, in principle all TDM
Since terminal station A cannot access other TDMA base stations, a problem arises in that the number of TDMA terminal stations that can be accommodated is reduced compared to the first method described above, which has the same number of call time slots.

SUMMARY OF THE INVENTION An object of the present invention is to provide a time division multiple access communication system that can eliminate the above-mentioned conventional problems, eliminate the need for an equalizer, and increase the number of terminal stations that can be accommodated.

[Means for solving problems]

The time division multiple access communication system of the present invention includes a plurality of TDMA base stations provided corresponding to a plurality of carrier waves, a plurality of TDMA terminal stations connected to these TDMA base stations using the carrier waves as a medium, and a plurality of TDMA terminal stations connected to the TDMA base stations using the carrier waves as a medium. TDMA base station and TDM
A TDMA system is configured with a control station that controls the A terminal station, the control station issues a control time slot through a specific TDMA base station, uses this control time slot to make the TDMA terminal station in an idle state standby, In addition, when a call is originated or received, the control time slot is used to instruct the TDMA terminal station where the call is made or received to perform the call connection by instructing the TDMA terminal station where the call is made or receiving the call. It consists of

〔Example] Next, the present invention will be explained with reference to the drawings.

The figure is a block diagram of one embodiment of the present invention. In the figure, 1 is a control station, which includes a large number of TDMA base stations 2
1, 2□, . . . 2 are connected.

Further, a combiner/distributor 3 is connected to these TDMA base stations, and a large number of TDMA terminal stations 55 are connected via a coaxial cable 4.
,5□,...5. is connected.

This TDMA terminal station has subscriber connection terminals 61, 6□ connected to different subscribers (not shown).

... 61, and correspondingly, the control station 1 has an exchange connection terminal 1 connected to an exchange (not shown).
+, 1□, . . . 71 are provided.

The exchange connection terminals 7I, 7□, . . . 71I and the subscriber connection terminals 6.26□, . . . 6m have a one-to-one correspondence, respectively. For example, switch connection terminal 7. The signal at the subscriber connection end 61
Conversely, the signal at the subscriber connection end 61 is output to the exchange connection end 7. is output to. Other exchange connection terminals 7□,...7
The same applies to the subscriber connection terminals 6□, . . . 61.

The TDMA base stations 21, 2□, . . . 2fi are configured to perform TDMA processing using a plurality of different carrier waves.

The control station 1 also receives a control signal from a certain TDMA base station via the distribution combiner 3 and coaxial cable 4.
Time slots for all TDMA terminal stations 51.5□
,...51. All these TDMA terminal stations 5
1.5□,...5. By receiving the control signal of this control time slot, TDMA base station 2. ．． 2
2. . . 2n, which may be used as a carrier wave of the TDMA base station, and among the communication time slots transmitted by the carrier wave, which may be used, are indicated.

Next, the TDMA communication method in the above configuration will be explained.

Exchange connection end 71 (a is 1 to m
The downlink signal to TDMA base station 2 . (b indicates any one of 1 to n)
is transmitted through the coaxial cable 4 by the carrier wave of the TDMA terminal station 5. Arrive at l. TDMA terminal station5. The signal is regenerated again at the subscriber connection end 6. and transmitted to subscribers not shown. Further, uplink signals from subscribers are transmitted to the exchange through the reverse route described above.

Here, the control time slot from the control station l is transmitted from a certain TDMA base station 2S (s is a specified value from 1 to n) to the distributor/combiner 3. Through coaxial cable 4, all T
It always arrives at the DMA terminal stations 51, 5□, . . . 5. All of these TDMA terminal stations receive a control signal for the control time slot, and this control signal tells them which of the eight TDM stations they can use, and which time slots to use for calls transmitted on that carrier wave. It is operating when idle to receive instructions for call time slots that may be used.

When a subscriber not shown in the figure attempts to make a call, the calling signal from the subscriber is detected by the TDMA terminal station 51 via six subscriber connection terminals. Once detected. TDMA terminal station 51 is TDM
Using the uplink control time slot to the A base station 28, a request is made to the control station 1 for permission of a carrier wave and a time slot that may be used. In response to this permission request, control station 1
T indicates the carrier wave and call time slot that may be used.
The TDMA terminal station 51 is instructed through the downlink control time slot of the DMA base station 25. TDM with instructions
The A terminal station 51 changes the frequency of the carrier wave and connects the voice signal from the subscriber to a call time slot that may be used.

On the other hand, the control station 1 connects the communication time slot on the carrier wave of the designated TDMA base station to the exchange connection end 71.

Due to the above-described operation, the subscriber connection end 61 and the exchange connection end 7. are connected to form a communication path. Therefore, all subscriber connections have access to any call time slot on any carrier.

Connections for incoming calls can access any call time slot on any carrier.

[Effects of the Invention] As explained above, the present invention provides a
A control time slot is issued through the base station, and the control time slot allows multiple TDs in an idle state to
The MA terminal station is placed on standby, and when a call is made or an incoming call is made, the carrier wave and time slot that may be used for the TDMA terminal station that makes the outgoing or incoming call are transmitted through its control time slot. Since call connection is performed by command, the transmission speed of the TDMA base station can be improved by the number of base stations compared to the case where one TDMA base station uses one carrier wave, and the transmission speed of the TDMA base station can be improved by the number of base stations. Good communication can be achieved even with a cable transmission line, and an equalizer for the transmission line can be omitted.

In addition, since all subscribers can use all call time slots on all carrier waves, the call volume that can be carried is large, and base stations can be gradually added in response to an increase in the number of subscribers. It is also possible to introduce a system that is highly practical, which also has the effect of building a highly practical system.

[Brief explanation of drawings]

The figure is a block diagram of one embodiment of the present invention. 1...Control station, 21, 2□,...2n...TDM
A base station, 3...combining distributor, 4...coaxial cable, 51°5□...5. ...TDMA terminal station, 6. ．．
6□,...61I...Subscriber connection end, 71,7□,
...7m...Exchange connection end.

Claims (1)

[Claims] (1) In a time division multiple access (TDMA) communication system, multiple carrier waves are used, multiple TDMA base stations are provided correspondingly to each carrier wave, and multiple TDMA base stations are connected to these TDMA base stations using each carrier wave as a medium. a TDMA terminal station,
A TDMA system is configured by the TDMA base station and a control station that controls the TDMA terminal station, and the control station issues a control time slot through a specific base station of the TDMA base station, and uses this control time slot to control the idle state. A carrier wave and a time that may be used for the TDMA terminal station that is in a state of standby and that the TDMA terminal station where the call is made or the call is received through the control time slot when a call is made or a call is received. A time division multiplex multiple access communication system characterized by connecting slots and making call connections.