CA1101074A - System for transmitting service communications - Google Patents
System for transmitting service communicationsInfo
- Publication number
- CA1101074A CA1101074A CA304,671A CA304671A CA1101074A CA 1101074 A CA1101074 A CA 1101074A CA 304671 A CA304671 A CA 304671A CA 1101074 A CA1101074 A CA 1101074A
- Authority
- CA
- Canada
- Prior art keywords
- amplifier
- service channel
- transmitter
- output
- receiver
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/0082—Monitoring; Testing using service channels; using auxiliary channels
- H04B17/0087—Monitoring; Testing using service channels; using auxiliary channels using auxiliary channels or channel simulators
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
- Radio Relay Systems (AREA)
- Dc Digital Transmission (AREA)
- Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
- Amplifiers (AREA)
- Interface Circuits In Exchanges (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
In a radio system composed of a transmitter with an associated receiver and a data transmission device with an associated voice instrument, service channel signals at a frequency at the lower end of the system base band are conducted by a service channel apparatus composed of separate service channel networks for the transmitter and data transmission device connected to the service channel connections thereof and all connected to a common bus bar.
In a radio system composed of a transmitter with an associated receiver and a data transmission device with an associated voice instrument, service channel signals at a frequency at the lower end of the system base band are conducted by a service channel apparatus composed of separate service channel networks for the transmitter and data transmission device connected to the service channel connections thereof and all connected to a common bus bar.
Description
7~
.
BACKGl~OUND OF THE INVENTION
The present invention reIates to apparatus forming a ~ervice channel ~n a radio syst'em in which the service channel carrier li`es at the`lower frequency end of the radio s:ystem base ~and..
Service ch.annel' s~stems are aids in communication which extend parallel to the'mai`n radio transmission path. They permi`t service conver~ati.ons for maintaining operation between radi`o stations and the.i`r reIa~ stations~ In order to make communi`catiQns over the servi.ce.'channeI as secure as possible, it ~5 ~no~n to exclude all operating devices from the trans-~is.si`on and to modul~te. the service channeI signal directly onto the emitted radio s~gnal~ Such.a proc:ess is very complicated ~nce extens.ive addi~t~onal devices are required and mainly al~o ~e'cause this serv~ce channel is i.ntended to be used not ~.
onl~ for teIephone conver~ations but also for the transmission o~ i`ndi.c~tion signals regarding operating states, switching s.i`gnals to stand~-de.v~.cesr and meas-ured value signals as , ~:
~ell,
.
BACKGl~OUND OF THE INVENTION
The present invention reIates to apparatus forming a ~ervice channel ~n a radio syst'em in which the service channel carrier li`es at the`lower frequency end of the radio s:ystem base ~and..
Service ch.annel' s~stems are aids in communication which extend parallel to the'mai`n radio transmission path. They permi`t service conver~ati.ons for maintaining operation between radi`o stations and the.i`r reIa~ stations~ In order to make communi`catiQns over the servi.ce.'channeI as secure as possible, it ~5 ~no~n to exclude all operating devices from the trans-~is.si`on and to modul~te. the service channeI signal directly onto the emitted radio s~gnal~ Such.a proc:ess is very complicated ~nce extens.ive addi~t~onal devices are required and mainly al~o ~e'cause this serv~ce channel is i.ntended to be used not ~.
onl~ for teIephone conver~ations but also for the transmission o~ i`ndi.c~tion signals regarding operating states, switching s.i`gnals to stand~-de.v~.cesr and meas-ured value signals as , ~:
~ell,
2 a 5UMM~R OF THE'INVENTI'ON
It is an object of th.e present invention to simplify such a system and to reduce the costs required for it~
This and other objects are accomplished according to the present invention by connecting the terminals of the -.
7~
service channels of transmitter with receiver and data transmission device with voice instrument each via a separate network to a bus bar, each network including two coupled operational amplifiers, connected so that one service channel signal is delivered to the direct input of the first operational amplifier, the first amplifier output is connected 1. to the bus bar via a resistor;
2. to the negating input of the second operational amplifier via a first voltage divider; and
It is an object of th.e present invention to simplify such a system and to reduce the costs required for it~
This and other objects are accomplished according to the present invention by connecting the terminals of the -.
7~
service channels of transmitter with receiver and data transmission device with voice instrument each via a separate network to a bus bar, each network including two coupled operational amplifiers, connected so that one service channel signal is delivered to the direct input of the first operational amplifier, the first amplifier output is connected 1. to the bus bar via a resistor;
2. to the negating input of the second operational amplifier via a first voltage divider; and
3. in feedback to its own negating input via a second voltage divider; and the direct input of the the second operational amplifier is connected, via a further resis-tor, with the bus bar. In the network associated with the transmitter with receiver, the direct input of the first amplifier receives the service channel signal appearing in the receiver and the output of the second amplifier is connected to the transmitter.
To complete the system the data transmission device with voice instrument has a similar network whose first amplifier has its direct input connected to receive signals Erom the data transmission device and the transmitter part of the voice instrument, and whose second amplifier has its output connected to the input of the data transmission device and the receiving part of the voice instrument, each via a further resistor, filters being connected ahead of the receiver and the transmitter of the voice instrument. The invention can be modified by connection of further transmitters with receivers connected to the bus bar.
Due ~o the grou~ed connection of the service line channels to a bus bar, this service line system is very much simplified and is expandable in any respect. The use of operational amplifiers completely prevents transmission of-an incoming conversation to the associated transmitter.
This is accomplished by a feedback connection of the incoming conversation at the negating input of the operational amplifier which is connected ahead of the transmitter.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a diagram of an embodiment of a circuit arrangement according to the invention for a transmitter with receiver.
Figure 2 is a diagram similar to that of Figure 1 showing two networks connected together via a bus line for a receiver with transmitter and data transmission device with voice instrument.
Figure 3 is a block diagram of a circuit for a combination utilizlng a simple end position.
Figure 4 is a diagram similar to that of Figure 3 of a combination at a relay station with substitute instruments.
~0~4 DES:CRIPTI:ON OF THE RRE:FER~ED EM~ODIMENTS
In the circuit shown in Figure 1, the incoming service channel from a receiver Eml is connected to the~direct input terminal of a first operational amplifier Vl. An input resistor Rl is connected between that input and ground.
The output of the operational amplifier Vl is connected via a resistor R4 to a BVS line. The output of amplifier Vl is also connected via a first voltage divider R5/R7 to the negating input of the second operational amplifier V2, and via a second voltage~divider R2/R3 to its own negating input.
The input to a transmitter Sdl is connected to the output of a second operational amplifier V2. The di.rect input of amplifier V2 is connected to the BUS line via a resistor R8. The BUS line is terminat:ed by a resistor R9.
The value of resistor R9 is dependent on the number of identical networks, n, connected to the BUS line and is calculated as follows: R9 ~ . The input resistance of amplifier V2 can : be neglected because it is much greater than R9.
A conversation signal coming from receiver Eml reaches transmitter Sdl via the ~irst operational amplifier Vl, a :resistor R5 and the se~ond operational amplifier V2. This signal is delivered to the negating input of amplifier V2 to which feedback resistor R6 is connected. The voltage divider R5/R7 couples this signal from receiver Eml to the negating input of the second operational amplifier V2.
The signal from the.output of amplifier Vl is also conducted via resistor R4, the BUS line and resistor R8 to the direct input of ampli~ier V2 and the signals fromampli`fier Vl reaching the inputs of amplifier V2 cancel one another out and become zero so that the transmit~er Sdl is not provided with any signal component from the signal from receiver Eml.
The voltage divider R2/R3 between the output and the negating input of the first operational amplifier Vl and the resistor R6 between the output and the negating input of the second operational amplifier V2 constitute feedback connections which serve to regulate the total gain of the individual amplifiers and to stabilize the degree of amplifi-cation.
Figure 2 shows a circuit arrangement providing the elements for the service channel for a receiver/transmitter at the same location as the arrangement and for a data transmission device with voice instrument remote from the arrangement and connected together via a sUS line. The arrangement is a receiver module in which the signal arriving at receiver Em is ~ed to the direct input of operational amplifier Vl via terminals a and b of a plug-in strip. Amplifiers Vl and V2 correspond to those of Figure 1, but the details of the circuit elements shown in Figure 1 are not shown here but are present in an actual circuit. The operational amplifier V2 has its output connected to terminal d and is connected with the transmitter Sd. The BUS line for the entire system is connected to terminal c. ~ -The BUS line is further connected to coupled further operational amplifiers V3 and V4 associated with the remote a~
transmission device with voice instrument. The incoming line DT. from ln the data transmission device is connected via terminal e to the direct input of the operational amplifier V3, to which is alsu connected the transmitter part SP of the voice instrument, both lines being decoupled via a resistor.
The output of the fourth operational amplifier V4 leads to the data transmission device output line DT t' at terminal f~ and to the receiving part RP of the voice instrument. Both of those lines are likewise decoupled via resistors.
Connections to parts SP and RP are effectuated via low-pass filters F. The filters F limit the speech band at 2,4 s in order that above this frequency the band is free for transmissions of control signals.
The feedback connections of Figure 1, which are not shown in detail in Figure 2 are also provided for the circuit unit of amplifiers V3 and V4 and prevent the incoming conversations from receiver Em from returning into the associated transmitter Sd. This applies as well for the transmitter and receiver parts of the voice instrument and for the data transmission device at terminals DT.
Figure 3 shows an em~odiment of a circuit provided for a simple end position~ A simple end position is connected to the end of a spark gap, and this simple end position receives from one direction respectively transmits to one direction otherwise to relay station (Fig. 4), which ~ 7 4 receives from many directions respectively transmits to many directions.
The circuit in the brokenline box corresponds in its details to the circ~it arrangement of Figure 2. The circuit Eml contains the receiver connected at terminal b and the circuit Sdl contains a transmitter Sdl connected to its service line at terminal d.
Figure 4 shows a circuit combination of instruments in a relay station. Here the active instruments are shown schematically in the drawing as Eml, Em2, Sdl and Sd2. Receiver Eml and transmitter Sdl which correspond to those of Figure 2, receive and send in the opposite directions from receiver Em2 and transmitter Sd2. Also are shown standby instruments, i.e. a receiver Eml~, transmitter Sdl', receiver Em2' and transmitter Sd2'.
The switches Sl and S2 inserted in the interconnection are electronically controllable switches which switch the system to the standby instruments when there is a malfunction in the active devices.
The relay station in Fig. ~ enables to receive a signal from two directions "All and 'IBII and to transmit a signal to two directions "A" and 'BII .
The notation of the terminals for connection are the same as in Fig. 2.
7~
It will be understood that the above descr.iption of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
To complete the system the data transmission device with voice instrument has a similar network whose first amplifier has its direct input connected to receive signals Erom the data transmission device and the transmitter part of the voice instrument, and whose second amplifier has its output connected to the input of the data transmission device and the receiving part of the voice instrument, each via a further resistor, filters being connected ahead of the receiver and the transmitter of the voice instrument. The invention can be modified by connection of further transmitters with receivers connected to the bus bar.
Due ~o the grou~ed connection of the service line channels to a bus bar, this service line system is very much simplified and is expandable in any respect. The use of operational amplifiers completely prevents transmission of-an incoming conversation to the associated transmitter.
This is accomplished by a feedback connection of the incoming conversation at the negating input of the operational amplifier which is connected ahead of the transmitter.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a diagram of an embodiment of a circuit arrangement according to the invention for a transmitter with receiver.
Figure 2 is a diagram similar to that of Figure 1 showing two networks connected together via a bus line for a receiver with transmitter and data transmission device with voice instrument.
Figure 3 is a block diagram of a circuit for a combination utilizlng a simple end position.
Figure 4 is a diagram similar to that of Figure 3 of a combination at a relay station with substitute instruments.
~0~4 DES:CRIPTI:ON OF THE RRE:FER~ED EM~ODIMENTS
In the circuit shown in Figure 1, the incoming service channel from a receiver Eml is connected to the~direct input terminal of a first operational amplifier Vl. An input resistor Rl is connected between that input and ground.
The output of the operational amplifier Vl is connected via a resistor R4 to a BVS line. The output of amplifier Vl is also connected via a first voltage divider R5/R7 to the negating input of the second operational amplifier V2, and via a second voltage~divider R2/R3 to its own negating input.
The input to a transmitter Sdl is connected to the output of a second operational amplifier V2. The di.rect input of amplifier V2 is connected to the BUS line via a resistor R8. The BUS line is terminat:ed by a resistor R9.
The value of resistor R9 is dependent on the number of identical networks, n, connected to the BUS line and is calculated as follows: R9 ~ . The input resistance of amplifier V2 can : be neglected because it is much greater than R9.
A conversation signal coming from receiver Eml reaches transmitter Sdl via the ~irst operational amplifier Vl, a :resistor R5 and the se~ond operational amplifier V2. This signal is delivered to the negating input of amplifier V2 to which feedback resistor R6 is connected. The voltage divider R5/R7 couples this signal from receiver Eml to the negating input of the second operational amplifier V2.
The signal from the.output of amplifier Vl is also conducted via resistor R4, the BUS line and resistor R8 to the direct input of ampli~ier V2 and the signals fromampli`fier Vl reaching the inputs of amplifier V2 cancel one another out and become zero so that the transmit~er Sdl is not provided with any signal component from the signal from receiver Eml.
The voltage divider R2/R3 between the output and the negating input of the first operational amplifier Vl and the resistor R6 between the output and the negating input of the second operational amplifier V2 constitute feedback connections which serve to regulate the total gain of the individual amplifiers and to stabilize the degree of amplifi-cation.
Figure 2 shows a circuit arrangement providing the elements for the service channel for a receiver/transmitter at the same location as the arrangement and for a data transmission device with voice instrument remote from the arrangement and connected together via a sUS line. The arrangement is a receiver module in which the signal arriving at receiver Em is ~ed to the direct input of operational amplifier Vl via terminals a and b of a plug-in strip. Amplifiers Vl and V2 correspond to those of Figure 1, but the details of the circuit elements shown in Figure 1 are not shown here but are present in an actual circuit. The operational amplifier V2 has its output connected to terminal d and is connected with the transmitter Sd. The BUS line for the entire system is connected to terminal c. ~ -The BUS line is further connected to coupled further operational amplifiers V3 and V4 associated with the remote a~
transmission device with voice instrument. The incoming line DT. from ln the data transmission device is connected via terminal e to the direct input of the operational amplifier V3, to which is alsu connected the transmitter part SP of the voice instrument, both lines being decoupled via a resistor.
The output of the fourth operational amplifier V4 leads to the data transmission device output line DT t' at terminal f~ and to the receiving part RP of the voice instrument. Both of those lines are likewise decoupled via resistors.
Connections to parts SP and RP are effectuated via low-pass filters F. The filters F limit the speech band at 2,4 s in order that above this frequency the band is free for transmissions of control signals.
The feedback connections of Figure 1, which are not shown in detail in Figure 2 are also provided for the circuit unit of amplifiers V3 and V4 and prevent the incoming conversations from receiver Em from returning into the associated transmitter Sd. This applies as well for the transmitter and receiver parts of the voice instrument and for the data transmission device at terminals DT.
Figure 3 shows an em~odiment of a circuit provided for a simple end position~ A simple end position is connected to the end of a spark gap, and this simple end position receives from one direction respectively transmits to one direction otherwise to relay station (Fig. 4), which ~ 7 4 receives from many directions respectively transmits to many directions.
The circuit in the brokenline box corresponds in its details to the circ~it arrangement of Figure 2. The circuit Eml contains the receiver connected at terminal b and the circuit Sdl contains a transmitter Sdl connected to its service line at terminal d.
Figure 4 shows a circuit combination of instruments in a relay station. Here the active instruments are shown schematically in the drawing as Eml, Em2, Sdl and Sd2. Receiver Eml and transmitter Sdl which correspond to those of Figure 2, receive and send in the opposite directions from receiver Em2 and transmitter Sd2. Also are shown standby instruments, i.e. a receiver Eml~, transmitter Sdl', receiver Em2' and transmitter Sd2'.
The switches Sl and S2 inserted in the interconnection are electronically controllable switches which switch the system to the standby instruments when there is a malfunction in the active devices.
The relay station in Fig. ~ enables to receive a signal from two directions "All and 'IBII and to transmit a signal to two directions "A" and 'BII .
The notation of the terminals for connection are the same as in Fig. 2.
7~
It will be understood that the above descr.iption of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Apparatus forming a service channel in a radio system composed of a transmitter with an associated receiver and a data transmission device with an associated voice instrument, each having separate terminals, and respective service channel connections, signals being sent over the service channel at the lower end of the system base band, comprising separate service channel networks for the transmitter and data transmission device connected to said service channel connections thereof and all connected to a common bus bar, and wherein one of said net-works comprises: first and second operational amplifiers, said first amplifier having its direct input connected to receive service channel signals and said second amplifier having its output connected to deliver service channel signals; a first resistor connecting the output of said first amplifier to the bus bar; a first voltage divider connecting the output of said first amplifier to the negating input of said second amplifier;
a second voltage divider connecting the output of said first amplifier to the negating input thereof; and a second resistor connecting the direct input of said second amplifier to the bus bar, whereby the output of said first amplifier is connected to the direct input of said second amplifier via said first re-sistor, the bus bar and said second resistor.
a second voltage divider connecting the output of said first amplifier to the negating input thereof; and a second resistor connecting the direct input of said second amplifier to the bus bar, whereby the output of said first amplifier is connected to the direct input of said second amplifier via said first re-sistor, the bus bar and said second resistor.
2. An arrangement as defined in claim 1 wherein said one network is associated with the transmitter and its receiver, the direct input of said first amplifier is connected to receive service channel signals from the receiver associated with the transmitter, the output of said second amplifier is connected to deliver service channel signals to the transmitter.
3. An arrangement as defined in claim 1 wherein said one network is associated with the data transmission device and its voice instrument and the direct input of said first amplifier is connected to receive service channel signals from the data transmission device and the transmitter part of the voice instrument, and comprising further resistors connecting the out-put of said second amplifier to the input of the data transmission and the receiver part of the voice instrument, respectively.
4. An arrangement as defined in claim 3 further compris-ing respective filters connected in the signal path from the transmitter part of the voice instrument to the direct input of said first amplifier and in the signal path from the output of said second amplifier to the receiver part of the voice instru-ment.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2725063A DE2725063C2 (en) | 1977-06-03 | 1977-06-03 | System for the transmission of a service channel |
| DEP2725063.1 | 1977-06-03 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1101074A true CA1101074A (en) | 1981-05-12 |
Family
ID=6010611
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA304,671A Expired CA1101074A (en) | 1977-06-03 | 1978-06-02 | System for transmitting service communications |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS543405A (en) |
| BR (1) | BR7803522A (en) |
| CA (1) | CA1101074A (en) |
| CH (1) | CH630761A5 (en) |
| DE (1) | DE2725063C2 (en) |
| FR (1) | FR2393478A1 (en) |
| GB (1) | GB1603159A (en) |
| NL (1) | NL189106C (en) |
| SE (1) | SE442695B (en) |
| YU (1) | YU128778A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2948077C2 (en) * | 1979-11-29 | 1984-02-02 | ANT Nachrichtentechnik GmbH, 7150 Backnang | Active hybrid circuit for telephone lines |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49100914A (en) * | 1973-01-12 | 1974-09-24 |
-
1977
- 1977-06-03 DE DE2725063A patent/DE2725063C2/en not_active Expired
-
1978
- 1978-05-26 GB GB22929/78A patent/GB1603159A/en not_active Expired
- 1978-05-30 YU YU01287/78A patent/YU128778A/en unknown
- 1978-06-01 BR BR787803522A patent/BR7803522A/en unknown
- 1978-06-01 SE SE7806456A patent/SE442695B/en not_active IP Right Cessation
- 1978-06-01 JP JP6629278A patent/JPS543405A/en active Pending
- 1978-06-01 CH CH601978A patent/CH630761A5/en not_active IP Right Cessation
- 1978-06-01 NL NLAANVRAGE7805980,A patent/NL189106C/en not_active IP Right Cessation
- 1978-06-02 FR FR7816612A patent/FR2393478A1/en active Granted
- 1978-06-02 CA CA304,671A patent/CA1101074A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| NL7805980A (en) | 1978-12-05 |
| FR2393478B1 (en) | 1983-07-22 |
| CH630761A5 (en) | 1982-06-30 |
| DE2725063A1 (en) | 1978-12-07 |
| SE442695B (en) | 1986-01-20 |
| BR7803522A (en) | 1979-02-13 |
| NL189106B (en) | 1992-08-03 |
| NL189106C (en) | 1993-01-04 |
| YU128778A (en) | 1982-06-30 |
| DE2725063C2 (en) | 1983-01-13 |
| SE7806456L (en) | 1978-12-04 |
| JPS543405A (en) | 1979-01-11 |
| FR2393478A1 (en) | 1978-12-29 |
| GB1603159A (en) | 1981-11-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |