JPS63262982A - Bidirectional catv system - Google Patents
Bidirectional catv systemInfo
- Publication number
- JPS63262982A JPS63262982A JP62097708A JP9770887A JPS63262982A JP S63262982 A JPS63262982 A JP S63262982A JP 62097708 A JP62097708 A JP 62097708A JP 9770887 A JP9770887 A JP 9770887A JP S63262982 A JPS63262982 A JP S63262982A
- Authority
- JP
- Japan
- Prior art keywords
- line
- band
- signal
- switch circuit
- switch
- 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
- 230000002457 bidirectional effect Effects 0.000 title description 8
- 238000011144 upstream manufacturing Methods 0.000 claims description 15
- 238000001514 detection method Methods 0.000 claims description 7
- 238000004891 communication Methods 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔概要〕
双方向増幅装置を備え、双方向データ通信を行うＣＡＴ
Ｖシステムにおいて、上り帯域の使用回線にスイッチ回
路を設け、使用されない回線を切り離すことにより、上
り帯域に流台する雑音を低減したものである。[Detailed Description of the Invention] [Summary] CAT equipped with a bidirectional amplifier and performing bidirectional data communication
In the V system, noise flowing into the upstream band is reduced by providing a switch circuit on the line used in the upstream band and disconnecting the line that is not used.
本発明は双方向ＣＡＴＶシステムの改良に関する。 The present invention relates to improvements in two-way CATV systems.
双方向ＣＡＴＶシステムでは、センタを発し、幹線から
支線へ分岐され端末に至る下り帯域と、逆向きに端末か
ら発して逐次収集合流されセンタに至る上り帯域とがあ
る。In a two-way CATV system, there is a downstream band that originates from the center, branches from the main line to branch lines, and reaches the terminal, and an upstream band that originates from the terminal in the opposite direction, is sequentially collected and merged, and reaches the center.
この様な回線システムにおいては、データ伝送の品質を
双方向において、良好に維持することが望ましい。In such a line system, it is desirable to maintain good data transmission quality in both directions.
従来、双方向増幅装置を使用するＣＡＴＶシステムは第
３図に示す様に構成されている。例えば幹線１と２はフ
ィルタ６−１．６−２で上りと下りの帯域に分離されそ
れぞれ増幅器４−１．４−２で増幅される。また、幹線
から分岐線３へ分岐する場合は、増幅器５−１．５−２
とフィルタ６−３が使用される。Conventionally, a CATV system using a bidirectional amplifier is configured as shown in FIG. For example, trunk lines 1 and 2 are separated into upstream and downstream bands by filters 6-1.6-2 and amplified by amplifiers 4-1.4-2, respectively. In addition, when branching from the main line to branch line 3, amplifier 5-1.5-2
and filter 6-3 are used.
ここで、上り帯域は、分岐線３からフィルタ６−３の低
域フィルタＬを介し増幅器５−２、増幅器４−２で増幅
され、センターへ送られる。Here, the upstream band is amplified by the amplifier 5-2 and the amplifier 4-2 from the branch line 3 through the low-pass filter L of the filter 6-3, and is sent to the center.
ＣＡＴＶシステムの構成によっては分岐線は更に多数の
分岐をもつ。Depending on the configuration of the CATV system, the branch line may have more branches.
−ヒ記従来の双方向ＣＡＴＶシステムにおいては、特に
上り帯域において、分岐線に発生される雑音と幹線から
発生する雑音が相加合流されてセンタに達し、大きな雑
音となり回線品質に支障を与えることが問題となる。- H Note: In conventional two-way CATV systems, especially in the upstream band, noise generated in branch lines and noise generated from main lines are additively combined and reach the center, resulting in large noise that interferes with line quality. becomes a problem.
そこで雑音対策の一つとして、ブリージャ・ゲート・コ
ントローラ（ＢＧＣ）を使用することが提案されている
。Therefore, as one measure against noise, it has been proposed to use a bleeder gate controller (BGC).
このＢＧＣ方式は、ポーリングなどセンタ主導型の多重
アクセス方式となり、端末主導に出来ない。This BGC method is a center-led multiple access method such as polling, and cannot be terminal-led.
例えば、キャリア検出多重アクセス／衝突検出（Ｃ５Ｍ
Ａ／ＣＤ）方式は、アクセス制御回路で伝送路の空きを
確認した場合、端末は直ちに送信を開始する。信号送出
開始後に他の端末のアクセス制御回路が同様に空きを検
出して送信を開始したため信号が衝突するような場合は
、この状態を検出して送信を停止する様にし、多重アク
セスを可能にした方式である。Ｃ３ＭＡ／ＣＤ方式は端
末主導型の多重アクセス方式である。For example, carrier sense multiple access/collision detection (C5M
In the A/CD) method, when the access control circuit confirms that the transmission path is free, the terminal immediately starts transmitting. If the access control circuit of another terminal similarly detects an empty space and starts transmission after the start of signal transmission, resulting in signal collision, this condition is detected and transmission is stopped, allowing multiple access. This is the method that was used. The C3MA/CD system is a terminal-initiated multiple access system.
この様に端末が能動的に通信する方式を実現しようとす
る場合、端末受動式になる従来のＢＧＣ方式は使用出来
ないという問題がある。When trying to implement a system in which terminals actively communicate in this way, there is a problem in that the conventional BGC system, in which terminals are passive, cannot be used.
Ｃ問題点を解決するための手段〕
−Ｆ記の問題点は、第１図の原理図に示す様に、双方向
増幅装置の−Ｅり帯域に、使用回線毎に回線用帯域フィ
ルタ１．７．１８、スイッチ１５、信号検出回路Ｉ６を
備え、信号検出回路１６に回線信号が検出されないとき
スイッチ１５を開放して信号回線を遮断する様に構成し
たスイッチ回路１４を設けた本発明の双方向ＣＡＴＶシ
ステムによって解決される。Means for Solving Problem C] The problem in item -F is that, as shown in the principle diagram of FIG. 1, a line bandpass filter 1. 7.18, both of the present invention are provided with a switch circuit 14 comprising a switch 15 and a signal detection circuit I6, and configured to open the switch 15 and cut off the signal line when the signal detection circuit 16 does not detect a line signal. The problem is solved by a direct CATV system.
本発明によれば、上り帯域の信号回線毎に設置されたス
イッチ１５は、信号検出回路１６によって、上り帯域中
の回線に信号がないことを検出したとき、該当回線のス
イッチ１５を切離し、無信号回線から雑音信号がセンタ
へ向い収集合流されることがない様にする。According to the present invention, when the signal detection circuit 16 detects that there is no signal on the line in the upstream band, the switch 15 installed for each signal line in the upstream band disconnects the switch 15 of the corresponding line and disables the signal line. To prevent noise signals from being collected and merged from a signal line toward a center.
第２図の本発明一実施例の双方向ＣＡＴＶ装置のブロッ
ク回路図によって本発明を説明する。The present invention will be explained with reference to a block circuit diagram of a bidirectional CATV device according to an embodiment of the present invention shown in FIG.
通常、上り帯域と下り帯域は帯域分割され、上り帯域に
は低域がまた下り帯域には高域が割当られている。Normally, the upstream band and the downstream band are divided into bands, with a low frequency band assigned to the upstream band and a high frequency band assigned to the downstream band.
図において、分岐線２３からの上り帯域はフィルタ２６
−３の低域フィルタＬ、増幅器２５−２、幹線上の増幅
器２４−２、フィルタ２６−１の低域フィルタＬを介し
センタへ接続する。In the figure, the upstream band from the branch line 23 is filtered by the filter 26.
-3 low-pass filter L, amplifier 25-2, amplifier 24-2 on the main line, and filter 26-1 low-pass filter L to connect to the center.
本発明よれば、上り線路の途中にスイッチ回路１４を設
ける。According to the present invention, the switch circuit 14 is provided in the middle of the upstream line.
スイッチ回路１４は上′り帯域に含まれる回線毎にスイ
ッチ１５−１〜ｎを備え、帯域フィルタ１７−１とｉ’
ａ−ｉ乃至１７−ｎと１８−ｎによ′って回線信号を選
択し、信号検出回路１６−１〜１６−ｎにより回線信号
の有無を検出し、信号が検出されないときはスイッチを
開放する。The switch circuit 14 includes switches 15-1 to 15-n for each line included in the upper band, and includes a bandpass filter 17-1 and i'
A line signal is selected by a-i to 17-n and 18-n, the presence or absence of a line signal is detected by signal detection circuits 16-1 to 16-n, and the switch is opened when no signal is detected. do.
帯域フィルタ１９．２０は上り帯域の増幅器の自動利得
調整を働かせるためのパイロット信号を通過させるため
のもので、スイッチ回路１４に関係無くバイロフト信号
の通過を可能にする。The bandpass filters 19 and 20 are for passing the pilot signal for operating the automatic gain adjustment of the upstream band amplifier, and allow the passage of the biloft signal regardless of the switch circuit 14.
ＣＡＴＶの上り帯域における温合雑音の発生を軽減し、
データ通信の品質を良好にするもので、その作用効果は
極めて大きい。Reduces the generation of heating noise in the upstream band of CATV,
It improves the quality of data communication, and its effects are extremely large.
第１図は本発明の原理図、
第２図は本発明一実施例の双方向ＣＡＴＶ装置のブロッ
ク回路図、
第３図は従来例の双方向ＣＡＴＶ装置のブロック回路図
である。
図において、
Ｉ、２．２１．２２は幹線、
３．２３は分岐線、
４−１．４−２．５−１ 、５−２．１３．２４−１．
２４−２．２５−１．２５−２は増幅器、
６−１．６−２．６−３．１１．１２．２６−１．２６
−２．２６−３はフィルタ、
１４はスイッチ回路、
１５．１５−１＝ｎはスイッチ、
１６．１６−１＝ｎは信号検出回路、
１７．１７−１〜ｎ 、 １８．１８−１〜ｎ 、 １
９．２０は帯域フィルタである。
第 １ 図
第 ２ 図
従来例の双方向ＣＡＴＶ装置のブロック回路間第 ３
図FIG. 1 is a principle diagram of the present invention, FIG. 2 is a block circuit diagram of a bidirectional CATV device according to an embodiment of the present invention, and FIG. 3 is a block circuit diagram of a conventional bidirectional CATV device. In the figure, I, 2.21.22 is the main line, 3.23 is the branch line, 4-1.4-2.5-1, 5-2.13.24-1.
24-2.25-1.25-2 is an amplifier, 6-1.6-2.6-3.11.12.26-1.26
-2.26-3 is a filter, 14 is a switch circuit, 15.15-1=n is a switch, 16.16-1=n is a signal detection circuit, 17.17-1~n, 18.18-1~ n, 1
9.20 is a bandpass filter. Figure 1 Figure 2 Figure 3 Between block circuits of conventional bidirectional CATV equipment
figure
Claims (1)
８）、スイッチ（１５）、信号検出回路（１６）からな
るスイッチ回路（１４）を備え、該信号検出回路（１６
）が無信号時、該スイッチ（１５）を遮断する様に構成
したことを特徴とする双方向ＣＡＴＶシステム。Line band filter (17) (1) is installed on the line used for upstream band.
8), a switch circuit (14) consisting of a switch (15), and a signal detection circuit (16);
) is configured to shut off the switch (15) when there is no signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62097708A JPS63262982A (en) | 1987-04-20 | 1987-04-20 | Bidirectional catv system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62097708A JPS63262982A (en) | 1987-04-20 | 1987-04-20 | Bidirectional catv system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63262982A true JPS63262982A (en) | 1988-10-31 |
Family
ID=14199413
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62097708A Pending JPS63262982A (en) | 1987-04-20 | 1987-04-20 | Bidirectional catv system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63262982A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009512337A (en) * | 2005-10-12 | 2009-03-19 | トムソン ライセンシング | Band-switchable taps and amplifiers used in cable systems |
| JP2010263403A (en) * | 2009-05-07 | 2010-11-18 | Synclayer Inc | Hfc system |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49108918A (en) * | 1972-04-24 | 1974-10-16 | ||
| JPS59161937A (en) * | 1983-03-07 | 1984-09-12 | Miharu Tsushin Kk | Group noise suppressing method for bidirectional catv system |
-
1987
- 1987-04-20 JP JP62097708A patent/JPS63262982A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49108918A (en) * | 1972-04-24 | 1974-10-16 | ||
| JPS59161937A (en) * | 1983-03-07 | 1984-09-12 | Miharu Tsushin Kk | Group noise suppressing method for bidirectional catv system |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009512337A (en) * | 2005-10-12 | 2009-03-19 | トムソン ライセンシング | Band-switchable taps and amplifiers used in cable systems |
| JP2010263403A (en) * | 2009-05-07 | 2010-11-18 | Synclayer Inc | Hfc system |
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