JPH07307937A - Up joint noise suppressing method for bidirectional catv system and relay amplifier to be used for the same - Google Patents
Up joint noise suppressing method for bidirectional catv system and relay amplifier to be used for the sameInfo
- Publication number
- JPH07307937A JPH07307937A JP6121976A JP12197694A JPH07307937A JP H07307937 A JPH07307937 A JP H07307937A JP 6121976 A JP6121976 A JP 6121976A JP 12197694 A JP12197694 A JP 12197694A JP H07307937 A JPH07307937 A JP H07307937A
- Authority
- JP
- Japan
- Prior art keywords
- amplifier
- relay amplifier
- monitoring device
- remote monitoring
- side remote
- 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.)
- Pending
Links
Landscapes
- Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は双方向ＣＡＴＶシステム
における上り流合雑音抑圧方法とそれに使用される中継
増幅器に関するものであり、複数の宅内（端末）側から
の上り回線に混入して幹線に流合する雑音（流合雑音）
を低く抑えるためのものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for suppressing upstream combined noise in a bidirectional CATV system and a relay amplifier used for the method, which is mixed into upstream lines from a plurality of premises (terminals) to form a trunk line. Noise that merges (merging noise)
To keep the value low.
【０００２】[0002]
【従来の技術】現在の双方向ＣＡＴＶシステムは図３に
示す様に幹線Ａに多数の中継増幅器３がカスケード接続
され、各中継増幅器３により下り信号が分岐されて加入
者宅１に伝送され、また、各加入者宅１からの上り信号
は前記中継増幅器３を通して幹線側に送り込られるよう
にしてある。図３の１１は上り幹線増幅回路、１２は分
岐器、７はた端末側遠隔制御装置、ＳＷはゲートスイッ
チ、８は上り分岐（又は分配）増幅回路（以下分岐・分
配増幅回路と記す）、１３は宅内保安器、２は宅内端末
器、１４はテレビ等である。2. Description of the Related Art In a current bidirectional CATV system, as shown in FIG. 3, a large number of relay amplifiers 3 are cascade-connected to a trunk line A, and a downstream signal is branched by each relay amplifier 3 and transmitted to a subscriber's home 1. The upstream signal from each subscriber's house 1 is sent to the trunk side through the relay amplifier 3. In FIG. 3, 11 is an upstream trunk amplifier circuit, 12 is a branching device, 7 is a terminal side remote control device, SW is a gate switch, 8 is an upstream branch (or distribution) amplifier circuit (hereinafter referred to as a branch / distribution amplifier circuit), Reference numeral 13 is a home security device, 2 is a home terminal device, and 14 is a television or the like.
【０００３】図３の様に端末の加入者宅１内に下り信号
を送り、加入者宅１内の宅内端末器２からの上り信号を
幹線に送る宅内双方向システムでは、夫々の宅内端末器
２から発生する雑音が上り信号に混入したり、上り回線
に外部雑音が混入したりし、それらが幹線Ａに送り込ま
れ、幹線Ａを通してセンター５に上り雑音が流合する。
なお、図３の６はセンタ側遠隔制御装置である。As shown in FIG. 3, in a home interactive system in which a downlink signal is sent to the subscriber's home 1 of the terminal and an uplink signal from the home terminal 2 in the subscriber's home 1 is sent to the trunk line, each home terminal is The noise generated from 2 mixes with the upstream signal, or external noise mixes with the upstream line, and these are sent to the trunk line A, and the upstream noise flows into the center 5 through the trunk line A.
Incidentally, 6 in FIG. 3 is a center side remote control device.
【０００４】そこで従来は図３に示す様に中継増幅器３
内の上り分岐・分配増幅回路８の出力側に、上り信号の
通過・切断を制御できるスイッチ（ゲートスイッチ）Ｓ
Ｗを設け、そのゲートスイッチＳＷを必要に応じて切り
替えることにより流合雑音を抑圧することが一般的であ
った。Therefore, conventionally, as shown in FIG. 3, the relay amplifier 3 is used.
A switch (gate switch) S that can control passage / disconnection of an upstream signal to the output side of the upstream branch / distribution amplifier circuit 8 in
It has been common to suppress the ingress noise by providing W and switching the gate switch SW as necessary.
【０００５】[0005]
【発明が解決しようとする課題】しかし、図３のゲート
スイッチＳＷを切断すると流合雑音が遮断されるだけで
なく下り信号までも遮断されてしまい、宅内までの下り
信号の伝送（宅内双方向サービス）も不可能になるとい
う問題があった。この問題を解決して宅内双方向サービ
スを行うためには前記ゲートスイッチＳＷを全て通過と
しなければならず、それでは流合雑音が幹線に集まって
しまう。このため、図３のＣ点での信号対雑音比を、ゲ
ートスイッチＳＷを閉じない状態でＣ／Ｎとすると、ゲ
ートスイッチＳＷを閉じた状態では加入者宅１内及び上
り分岐・分配増幅回路８からの雑音ＮB が流合してＣ／
（Ｎ＋ＮB ）となり、悪化すると言う問題がある。However, when the gate switch SW of FIG. 3 is cut off, not only the ingress noise is cut off but also the downlink signal is cut off, so that the transmission of the downlink signal to the inside of the house (in-house bidirectional There was a problem that the service) would be impossible. In order to solve this problem and provide the in-home interactive service, all of the gate switches SW must be passed, which causes ingress noise to collect on the trunk line. Therefore, assuming that the signal-to-noise ratio at point C in FIG. 3 is C / N when the gate switch SW is not closed, the inside of the subscriber's home 1 and the upstream branch / distribution amplifier circuit when the gate switch SW is closed. Noise N B from 8 merges to C /
There is a problem that it becomes (N + N B ) and deteriorates.
【０００６】本発明の目的は宅内双方向サービスは損な
われずに流合雑音が抑制されて、信号対雑音比が悪化し
ないようにした上り流合雑音抑圧方法とそれに使用され
る中継増幅器を提供することにある。An object of the present invention is to provide an upstream ingress noise suppression method in which ingress noise is suppressed without deteriorating the in-home interactive service and the signal-to-noise ratio is not deteriorated, and a relay amplifier used for the same. Especially.
【０００７】[0007]
【課題を解決するための手段】本発明のうち請求項１の
双方向ＣＡＴＶシステムにおける上り流合雑音抑圧方法
は、図１の双方向ＣＡＴＶシステムにおける加入者宅１
の宅内端末器２から中継増幅器３までの上り信号レベル
を、中継増幅器３の標準入力レベルよりも高くし、中継
増幅器３に可変減衰器４を設け、その可変減衰器４をセ
ンタ５に設けたたセンタ側遠隔監視装置６と中継増幅器
１に設けた端末側遠隔監視装置７により制御して同中継
増幅器３から出力される上り信号レベルを減衰させるよ
うにしたものである。According to a first aspect of the present invention, a method of suppressing upstream combined noise in a bidirectional CATV system according to claim 1 is a subscriber home 1 in the bidirectional CATV system shown in FIG.
The upstream signal level from the in-home terminal 2 to the relay amplifier 3 is higher than the standard input level of the relay amplifier 3, the relay amplifier 3 is provided with the variable attenuator 4, and the variable attenuator 4 is provided in the center 5. The center side remote monitoring device 6 and the terminal side remote monitoring device 7 provided in the relay amplifier 1 are controlled to attenuate the upstream signal level output from the relay amplifier 3.
【０００８】本発明のうち請求項２の双方向ＣＡＴＶシ
ステムにおける中継増幅器は、図１に示す様に、双方向
ＣＡＴＶシステムにおける中継増幅器３の上り分岐（又
は分配）増幅回路８の出力側に、センタ５に設けたセン
タ側遠隔監視装置６と中継増幅器３に設けた端末側遠隔
監視装置７により減衰量を可変して加入者宅１から伝送
される上り信号レベルを可変可能な可変減衰器４を設け
てなるものである。The relay amplifier in the bidirectional CATV system according to claim 2 of the present invention is, as shown in FIG. 1, at the output side of the upstream branch (or distribution) amplifier circuit 8 of the relay amplifier 3 in the bidirectional CATV system. A variable attenuator 4 capable of varying the upstream signal level transmitted from the subscriber's home 1 by varying the amount of attenuation by the center side remote monitoring device 6 provided in the center 5 and the terminal side remote monitoring device 7 provided in the relay amplifier 3. Is provided.
【０００９】本発明のうち請求項３の双方向ＣＡＴＶシ
ステムにおける中継増幅器は、図１に示す様に、請求項
２における上り分岐・分配増幅回路８を設けずに可変減
衰器４を設けてなるものである。As shown in FIG. 1, the relay amplifier in the bidirectional CATV system according to the third aspect of the present invention is provided with the variable attenuator 4 without providing the upstream branch / distribution amplifier circuit 8 according to the second aspect. It is a thing.
【００１０】[0010]
【作用】本発明のうち請求項１の双方向ＣＡＴＶシステ
ムにおける上り流合雑音抑圧方法では、加入者宅１から
中継増幅器３に送られる上り信号のレベルを中継増幅器
３の標準力レベルよりも高くしたので、加入者宅１と中
継増幅器３との間における信号対雑音比は悪化しない。
また、標準入力レベルよりも高いレベルの上り信号を中
継増幅器３において減衰させるので、必要以上に高いレ
ベルの上り信号が幹線に送り込まれることがなく、歪等
の問題が生ぜず、中継増幅器３と幹線との間の信号レベ
ル及び信号対雑音比は変化しない。しかも、その減衰は
センタ５に設けたセンタ側遠隔監視装置６と中継増幅器
３に設けた端末側遠隔監視装置７にとにより、中継増幅
器３に設けた可変減衰器４の減衰量を制御して行うの
で、減衰が自動的に且つリアルタイムに行われる。In the method for suppressing upstream combined noise in the bidirectional CATV system according to claim 1 of the present invention, the level of the upstream signal sent from the subscriber's home 1 to the relay amplifier 3 is higher than the standard power level of the relay amplifier 3. Therefore, the signal-to-noise ratio between the subscriber's home 1 and the relay amplifier 3 does not deteriorate.
Further, since the upstream signal having a level higher than the standard input level is attenuated in the relay amplifier 3, the upstream signal having a higher level than necessary is not sent to the trunk line, the problem such as distortion does not occur, and the relay amplifier 3 is The signal level to and from the mains and the signal-to-noise ratio do not change. Moreover, the attenuation is controlled by the center side remote monitoring device 6 provided in the center 5 and the terminal side remote monitoring device 7 provided in the relay amplifier 3 to control the amount of attenuation of the variable attenuator 4 provided in the relay amplifier 3. As it does so, the damping is done automatically and in real time.
【００１１】本発明のうち請求項２の双方向ＣＡＴＶシ
ステムにおける中継増幅器では、中継増幅器３の上り分
岐・分配増幅回路８の出力側に可変減衰器４を設けてな
るので、加入者宅１から上り分岐・分配増幅回路８に送
られる上り信号のレベルを中継増幅器３の標準力レベル
よりも高くし、センタ５に設けたセンタ側遠隔監視装置
６と中継増幅器３に設けた端末側遠隔監視装置７により
可変減衰器４の減衰量を制御して上り信号を減衰させれ
ば、必要以上に高いレベルの上り信号が幹線に送り込ま
れることがなく、歪等の問題が生ぜず、上り分岐・分配
増幅回路８と幹線との間の信号レベル及び信号対雑音比
は変化しない。In the relay amplifier in the bidirectional CATV system according to claim 2 of the present invention, since the variable attenuator 4 is provided on the output side of the upstream branch / distribution amplifier circuit 8 of the relay amplifier 3, the subscriber's home 1 The level of the upstream signal sent to the upstream branching / distributing / amplifying circuit 8 is made higher than the standard power level of the relay amplifier 3, and the center side remote monitoring device 6 provided in the center 5 and the terminal side remote monitoring device provided in the relay amplifier 3. If the amount of attenuation of the variable attenuator 4 is controlled by 7 to attenuate the upstream signal, an undesirably high level upstream signal will not be sent to the trunk line, problems such as distortion will not occur, and upstream branching / distribution The signal level and the signal-to-noise ratio between the amplifier circuit 8 and the main line do not change.
【００１２】本発明のうち請求項３の双方向ＣＡＴＶシ
ステムにおける中継増幅器では、中継増幅器３に前記上
り分岐・分配増幅回路８を設けずに減衰器４を設けたの
で、加入者宅１から中継増幅器３に送られる上り信号の
レベルを中継増幅器３の標準力レベルよりも高くし且つ
中継増幅器３で増幅する必要が無いほど高くし、センタ
５に設けたセンタ側遠隔監視装置６と中継増幅器３に設
けた端末側遠隔監視装置７により可変減衰器４を制御し
てその上り信号を減衰させて、必要以上に高いレベルの
上り信号が幹線に送り込まれないようにすることができ
る。従って、上り信号の歪等の問題が生ぜず、中継増幅
器３と幹線との間の信号レベル及び信号対雑音比は変化
しない。In the relay amplifier in the bidirectional CATV system according to claim 3 of the present invention, since the attenuator 4 is provided in the relay amplifier 3 without providing the upstream branching / dividing amplifier circuit 8, the relay from the subscriber home 1 is performed. The level of the upstream signal sent to the amplifier 3 is made higher than the standard power level of the relay amplifier 3 and so high as not to be amplified by the relay amplifier 3, and the center side remote monitoring device 6 provided in the center 5 and the relay amplifier 3 are provided. It is possible to control the variable attenuator 4 by the terminal-side remote monitoring device 7 provided in the above to attenuate the upstream signal and prevent an upstream signal of a higher level than necessary from being sent to the trunk line. Therefore, problems such as distortion of the upstream signal do not occur, and the signal level and signal-to-noise ratio between the relay amplifier 3 and the trunk line do not change.
【００１３】[0013]
【中継増幅器の実施例１】図１は本発明の中継増幅器を
使用したＣＡＴＶシステムの第１の実施例を示すもので
あり、このＣＡＴＶシステムでは幹線にカスケード接続
された夫々の中継増幅器３において下り信号の一部が分
岐されて加入者宅１に伝送され、各加入者宅１からの上
り信号が前記中継増幅器３を通して幹線に送り込まれる
ようにしてある。[Embodiment 1 of Repeater Amplifier] FIG. 1 shows a first embodiment of a CATV system using the repeater amplifier of the present invention. In this CATV system, each repeater amplifier 3 cascade-connected to a trunk line is connected to a downlink. A part of the signal is branched and transmitted to the subscriber's home 1, and the upstream signal from each subscriber's home 1 is sent to the trunk line through the relay amplifier 3.
【００１４】図１の３は中継増幅器であり、これは上り
幹線増幅回路１１、分岐器１２、上り分岐・分配増幅回
路８、それに本発明の特徴である可変減衰器４、遠隔制
御装置７を備えてなる。Reference numeral 3 in FIG. 1 is a relay amplifier, which comprises an upstream trunk amplifier circuit 11, a branching device 12, an upstream branching / distributing amplifier circuit 8, a variable attenuator 4, which is a feature of the present invention, and a remote control device 7. Be prepared.
【００１５】図１の１は加入者宅であり、これは分岐器
１２により中継増幅器３に連結されており、宅内保安器
１５、宅内端末器２、テレビ等１４を備えており、これ
らは図３に示す従来のそれらと同じものである。Reference numeral 1 in FIG. 1 denotes a subscriber's home, which is connected to a relay amplifier 3 by a branching device 12 and is provided with a home protection device 15, a home terminal device 2, a television set 14, etc. These are the same as those of the related art shown in FIG.
【００１６】[0016]
【中継増幅器の実施例２】図２は本発明の中継増幅器を
使用したＣＡＴＶシステムの第２の実施例を示すもので
あり、このＣＡＴＶシステムは中継増幅器３に図１の上
り分岐・分配増幅回路８を設けずに可変減衰器４を設け
たものであり、それ以外の構成は図１と同じである。[Second Embodiment of Repeater Amplifier] FIG. 2 shows a second embodiment of a CATV system using the repeater amplifier of the present invention. This CATV system includes a repeater amplifier 3 and an upstream branch / distribution amplifier circuit of FIG. The variable attenuator 4 is provided without providing 8, and other configurations are the same as those in FIG.
【００１７】図１、２における５はセンタであり、これ
はヘッドエンド１６、遠隔制御装置６、宅内端末制御装
置１７を備えている。遠隔制御装置は中継増幅器３に設
けた遠隔制御装置６を制御するためのものであり、宅内
端末制御装置１７は加入者宅１における宅内端末器２を
制御するものである。Reference numeral 5 in FIGS. 1 and 2 is a center, which is provided with a head end 16, a remote control device 6, and a home terminal control device 17. The remote control device is for controlling the remote control device 6 provided in the relay amplifier 3, and the home terminal control device 17 is for controlling the home terminal device 2 in the subscriber home 1.
【００１８】[0018]
【上り流合雑音抑圧方法の実施例１】本発明の上り流合
雑音抑圧方法の第１の実施例を図１のＣＡＴＶシステム
を用いて説明する。この実施例では図１の加入者宅１か
ら送り出される上り信号を、標準入力レベルよりも高い
レベルにして送り出して、中継増幅器３の上り分岐・分
配増幅回路８の入力側においても標準入力レベルより高
いレベルになるようにする。[First Embodiment of Upstream Combined Noise Suppression Method] A first embodiment of the upstream combined noise suppression method of the present invention will be described using the CATV system of FIG. In this embodiment, the upstream signal sent from the subscriber's home 1 in FIG. 1 is sent at a level higher than the standard input level, and the upstream side branching / distribution amplifier circuit 8 of the relay amplifier 3 also receives the upstream signal from the standard input level. Try to reach a higher level.
【００１９】そして、上り分岐・分配増幅回路８に入力
され、同増幅回路３をそのまま通過するか、上り分岐・
分配増幅回路８で増幅された上り信号を可変減衰器４に
より所定レベルまで減衰して幹線に送り込む。この減衰
は、可変減衰器４をセンタ５に設けたセンタ側遠隔監視
装置６と中継増幅器３に設けた端末側遠隔監視装置７に
より制御して行う。この結果、図１の幹線の入力部にお
ける信号対雑音比はＣ／［Ｎ＋（ＮB −α）］となり、
従来方式と比較して信号対雑音比を高くとることができ
る。ここでＮB は加入者宅１内及び上り分岐・分配増幅
回路８からの上り雑音、αは可変減衰器４の減衰量であ
る。Then, it is input to the upstream branch / distribution amplifier circuit 8 and passes through the same amplifier circuit 3 as it is,
The upstream signal amplified by the distribution amplifier circuit 8 is attenuated to a predetermined level by the variable attenuator 4 and sent to the main line. This attenuation is performed by controlling the variable attenuator 4 by the center side remote monitoring device 6 provided in the center 5 and the terminal side remote monitoring device 7 provided in the relay amplifier 3. As a result, the signal-to-noise ratio at the input part of the main line in FIG. 1 becomes C / [N + (N B −α)],
The signal-to-noise ratio can be increased as compared with the conventional method. Here, N B is the upstream noise from the subscriber's home 1 and from the upstream branch / distribution amplifier circuit 8, and α is the attenuation amount of the variable attenuator 4.
【００２０】[0020]
【上り流合雑音抑圧方法の実施例２】本発明の上り流合
雑音抑圧方法の第２の実施例を図２のＣＡＴＶシステム
を用いて説明する。この実施例では図２の加入者宅１か
ら送り出される上り信号を標準入力レベル以上で且つ中
継増幅器３で増幅する必要が無いほど高くし、その上り
信号を可変減衰器４により減衰させて必要以上に高いレ
ベルの上り信号が幹線に送り込まれないようにする。こ
の減衰は可変減衰器４の減衰量をセンタ５に設けたセン
タ側遠隔監視装置６と中継増幅器３に設けた端末側遠隔
監視装置７により制御して行う。これにより上り信号の
歪等の問題が生ぜず、中継増幅器３と幹線との間の信号
レベル及び信号対雑音比は変化しない。[Second Embodiment of Upstream Combined Noise Suppression Method] A second embodiment of the upstream combined noise suppression method of the present invention will be described with reference to the CATV system of FIG. In this embodiment, the upstream signal sent from the subscriber's home 1 in FIG. 2 is set to a level higher than the standard input level and so high that it is not necessary to be amplified by the relay amplifier 3, and the upstream signal is attenuated by the variable attenuator 4 to be more than necessary. Prevent high level upstream signals from entering the mains. This attenuation is performed by controlling the attenuation amount of the variable attenuator 4 by the center side remote monitoring device 6 provided in the center 5 and the terminal side remote monitoring device 7 provided in the relay amplifier 3. As a result, problems such as distortion of the upstream signal do not occur, and the signal level and signal-to-noise ratio between the relay amplifier 3 and the trunk line do not change.
【００２１】[0021]
【発明の効果】本発明の請求項１の上り流合雑音抑圧方
法では次の様な効果がある。 ．ゲートスイッチの制御を行うことなく必要な信号対
雑音比を確保でき、幹線内双方向サービス及び宅内双方
向サービスの実施が同時に可能となる。 ．幹線内の信号レベル・信号対雑音比に影響を及ぼす
ことはなく、従来の幹線内双方向サービスの実施も同時
に可能となる。 ．上り信号の減衰を、センタ５に設けたセンタ側遠隔
監視装置６と中継増幅器３に設けた端末側遠隔監視装置
７により、中継増幅器３に設けた可変減衰器４を制御し
て行うので、減衰が自動的に且つリアルタイムに的確に
行われる。The upstream combined noise suppressing method according to claim 1 of the present invention has the following effects. ． The necessary signal-to-noise ratio can be secured without controlling the gate switch, and the intra-mainline interactive service and the in-home interactive service can be performed at the same time. ． It does not affect the signal level and signal-to-noise ratio in the main line, and it is possible to implement the conventional two-way service in the main line at the same time. ． Attenuation of the upstream signal is performed by controlling the variable attenuator 4 provided in the relay amplifier 3 by the center-side remote monitoring device 6 provided in the center 5 and the terminal-side remote monitoring device 7 provided in the relay amplifier 3. Is accurately performed automatically and in real time.
【００２２】本発明の請求項２の中継増幅器では、上り
従来の幹線内双方向サービスに大幅な機能追加、変更等
を行うことなく、可変減衰器４と端末側遠隔監視装置７
にを付加するだけで幹線内双方向サービス・宅内双方向
サービスの両方が実施可能となる。In the repeater amplifier according to the second aspect of the present invention, the variable attenuator 4 and the terminal side remote monitoring device 7 are added without significantly adding or changing functions to the conventional bidirectional service in the trunk line.
It is possible to implement both in-main-line and in-home interactive services by simply adding
【００２３】本発明の請求項３の中継増幅器では、上り
従来の幹線内双方向サービスに大幅な機能追加、変更等
を行うことなく、従来設けられている上り分岐・分配増
幅回路８を取外して、可変減衰器４と端末側遠隔監視装
置７にを付加するだけで幹線内双方向サービス・宅内双
方向サービスの両方が実施可能となる。構成が簡略にな
る。また、上り分岐・分配増幅回路８を使用しないの
で、その部分の熱雑音が幹線系に加算されることがな
く、幹線系のみの熱雑音となり、熱雑音が少なくなる。In the repeater amplifier according to claim 3 of the present invention, the conventionally provided upstream branching / distributing amplifier circuit 8 is removed without adding a significant function to the conventional conventional two-way service in the trunk line or making a change. By only adding the variable attenuator 4 and the terminal-side remote monitoring device 7, both the intra-mainline interactive service and the in-home interactive service can be performed. The configuration is simplified. Further, since the upstream branching / distributing / amplifying circuit 8 is not used, the thermal noise of that portion is not added to the trunk system, and the thermal noise of only the trunk system is reduced, and the thermal noise is reduced.
【図１】本発明の中継増幅器の第１の実施例を示す説明
図。FIG. 1 is an explanatory diagram showing a first embodiment of a relay amplifier of the present invention.
【図２】本発明の中継増幅器の第２の実施例を示す説明
図。FIG. 2 is an explanatory diagram showing a second embodiment of the relay amplifier of the present invention.
【図３】従来の中継増幅器の説明図。FIG. 3 is an explanatory diagram of a conventional relay amplifier.
１ 加入者宅 ２ 宅内端末器 ３ 中継増幅器 ４ 可変減衰器 ５ センタ ６ センタ側遠隔監視装置 ７ 端末側遠隔監視装置 ８ 上り分岐（又は分配）増幅回路 1 subscriber's house 2 in-home terminal device 3 relay amplifier 4 variable attenuator 5 center 6 center side remote monitoring device 7 terminal side remote monitoring device 8 upstream branch (or distribution) amplification circuit
Claims (3)
宅（１）の宅内端末器（２）から中継増幅器（３）まで
の上り信号レベルを、中継増幅器（３）の標準入力レベ
ルよりも高くし、中継増幅器（３）に設けた可変減衰器
（４）の減衰量をセンタ（５）に設けたセンタ側遠隔監
視装置（６）と中継増幅器（３）に設けた端末側遠隔監
視装置（７）により制御して、中継増幅器（３）から出
力される上り信号レベルを減衰させるようにしたことを
特徴とする双方向ＣＡＴＶシステムにおける上り流合雑
音抑圧方法。1. An upstream signal level from a home terminal (2) of a subscriber's home (1) to a relay amplifier (3) in a two-way CATV system is set higher than a standard input level of the relay amplifier (3), The center-side remote monitoring device (6) provided in the center (5) and the terminal-side remote monitoring device (7) provided in the relay amplifier (3) for the attenuation amount of the variable attenuator (4) provided in the relay amplifier (3). The method according to claim 1, wherein the upstream signal level output from the repeater amplifier (3) is attenuated by the above method.
幅器（３）の上り分岐（又は分配）増幅回路（８）の出
力側に、センタ（５）に設けたたセンタ側遠隔監視装置
（６）と中継増幅器（３）に設けた端末側遠隔監視装置
（７）により減衰量を可変可能な可変減衰器（４）を設
けてなることを特徴とする中継増幅器。2. The center side remote monitoring device (6) provided in the center (5) is relayed to the output side of the upstream branch (or distribution) amplifier circuit (8) of the relay amplifier (3) in the bidirectional CATV system. A relay amplifier comprising a variable attenuator (4) capable of varying an attenuation amount by a terminal side remote monitoring device (7) provided in the amplifier (3).
幅器（３）に、請求項２における上り分岐（又は分配）
増幅回路（３）を設けずに、センタ（５）に設けたたセ
ンタ側遠隔監視装置（６）と中継増幅器（３）に設けた
端末側遠隔監視装置（７）により減衰量を可変可能な可
変減衰器（４）を設けたことを特徴とする中継増幅器。3. Uplink (or distribution) according to claim 2, in a relay amplifier (3) in a bidirectional CATV system.
The attenuation amount can be varied by the center side remote monitoring device (6) provided in the center (5) and the terminal side remote monitoring device (7) provided in the relay amplifier (3) without providing the amplifier circuit (3). A relay amplifier comprising a variable attenuator (4).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6121976A JPH07307937A (en) | 1994-05-11 | 1994-05-11 | Up joint noise suppressing method for bidirectional catv system and relay amplifier to be used for the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6121976A JPH07307937A (en) | 1994-05-11 | 1994-05-11 | Up joint noise suppressing method for bidirectional catv system and relay amplifier to be used for the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07307937A true JPH07307937A (en) | 1995-11-21 |
Family
ID=14824517
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6121976A Pending JPH07307937A (en) | 1994-05-11 | 1994-05-11 | Up joint noise suppressing method for bidirectional catv system and relay amplifier to be used for the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07307937A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002016898A (en) * | 2000-04-27 | 2002-01-18 | Maspro Denkoh Corp | Two-way catv system, transmission line apparatus, and center device |
| US6728968B1 (en) | 1999-06-17 | 2004-04-27 | Fujitsu Limited | Upward-joining-noise decreasing method and apparatus |
| US6868552B1 (en) | 1999-06-07 | 2005-03-15 | Fujitsu Limited | Ingress noise control system and ingress noise blocking device |
-
1994
- 1994-05-11 JP JP6121976A patent/JPH07307937A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6868552B1 (en) | 1999-06-07 | 2005-03-15 | Fujitsu Limited | Ingress noise control system and ingress noise blocking device |
| US6728968B1 (en) | 1999-06-17 | 2004-04-27 | Fujitsu Limited | Upward-joining-noise decreasing method and apparatus |
| JP2002016898A (en) * | 2000-04-27 | 2002-01-18 | Maspro Denkoh Corp | Two-way catv system, transmission line apparatus, and center device |
| JP4740464B2 (en) * | 2000-04-27 | 2011-08-03 | マスプロ電工株式会社 | Bi-directional CATV system, transmission line equipment, center equipment |
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