JPH0779468B2 - Interactive CATV system - Google Patents
Interactive CATV systemInfo
- Publication number
- JPH0779468B2 JPH0779468B2 JP61079193A JP7919386A JPH0779468B2 JP H0779468 B2 JPH0779468 B2 JP H0779468B2 JP 61079193 A JP61079193 A JP 61079193A JP 7919386 A JP7919386 A JP 7919386A JP H0779468 B2 JPH0779468 B2 JP H0779468B2
- Authority
- JP
- Japan
- Prior art keywords
- line
- upstream
- trunk
- catv system
- amplifier
- 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 - Lifetime
Links
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、同軸ケーブル等の広帯域伝送路を用いて、ヘ
ッドエンドから各加入者にテレビ信号等を分配すると共
に群別方式にて各加入者からヘッドエンドにテレビ信号
等を伝送する双方向CATVシステムに関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention uses a broadband transmission line such as a coaxial cable to distribute a television signal or the like from a head end to each subscriber, and to join each subscriber by a group-based method. The present invention relates to a bidirectional CATV system for transmitting a television signal or the like from a person to a headend.
従来、この種の双方向CATVシステムは、基幹伝送路であ
る幹線と、この幹線から分岐した信号をある１つの区画
に分配する分岐線と、この分岐線から更に分岐した信号
を各加入者に分配するための分配線とが樹枝状に接続さ
れて構成されていた。各加入者からヘッドエンドに伝送
される上り信号は加入者から分配線、分岐線、幹線を通
してヘッドエンドまで到達する。Conventionally, this type of bidirectional CATV system has a trunk line that is a trunk transmission line, a branch line that divides a signal branched from this trunk line into one section, and a signal that is further branched from this branch line to each subscriber. The distribution wiring and the distribution wiring were connected in a dendritic manner. Uplink signals transmitted from each subscriber to the headend reach the headend from the subscriber through distribution lines, branch lines, and trunk lines.
上述した双方向CATVシステムを第２図に示す。ただし、
第２図においては分岐線と分配線とが省略されている。
第２図において、１は信号を伝送路に送信すると共に伝
送路から受信するヘッドエンド、２は基幹伝送路として
の幹線、３は幹線２におけるケーブル損失を等化する幹
線増幅器、４は幹線２と各加入者とを接続するための分
配用入出力端子である。The bidirectional CATV system described above is shown in FIG. However,
In FIG. 2, branch lines and distribution lines are omitted.
In FIG. 2, 1 is a headend for transmitting signals to and receiving signals from a transmission line, 2 is a trunk line as a trunk transmission line, 3 is a main line amplifier for equalizing cable loss in the main line 2, and 4 is a main line 2. It is an input / output terminal for distribution for connecting to each subscriber.
双方向CATVシステムでは、FM放送波およびテレビ放送波
の再送信を基本サービスとしていることから、下り信号
帯域を一般に70MHz以上としており、上り信号帯域は双
方向中継器に使用される分離フィルタの実現性の点から
一般に50MHz以下となっている。Since the basic service of the bidirectional CATV system is the retransmission of FM broadcast waves and TV broadcast waves, the downlink signal band is generally set to 70 MHz or more, and the upstream signal band realizes a separation filter used for a bidirectional repeater. From the viewpoint of sex, it is generally below 50MHz.
一般に、加入者宅内のテレビ受像機、FMチューナには放
送波受信用の安価な市販の受信機が使用されており、前
記基本サービスの周波数配置を変更した場合、各加入者
は高価な専用受信機を新たに用意する必要があり、この
点からも周波数配置の変更は難しい。このため、中継器
の広帯域化が進んでも上り回線の帯域は拡大されない。
したがって、双方向データ通信等の利用が進むと、従来
の双方向CATVシステムでは上り回線の容量が不足すると
いう欠点があった。Generally, inexpensive commercial receivers for receiving broadcast waves are used for TV receivers and FM tuners in subscribers' houses, and if the frequency arrangement of the basic service is changed, each subscriber will receive expensive dedicated reception. Since it is necessary to prepare a new machine, it is difficult to change the frequency allocation from this point as well. Therefore, even if the band of the repeater is widened, the band of the uplink is not expanded.
Therefore, as the use of bidirectional data communication and the like progresses, the conventional bidirectional CATV system has a drawback that the uplink capacity is insufficient.
このような欠点を除去するために本発明は、群別方式を
用いて双方向伝送を行なう双方向CATVシステムにおい
て、双方向の伝送を行なう幹線中に設置され、この設置
点より下方の加入者から送出された上り信号は上り回線
出力端子へ出力する幹線増幅器と、上り回線出力端子と
ヘッドエンドとの間を接続して幹線増幅器から出力され
た上り信号を伝送する上り専用回線とを有するものであ
る。In order to eliminate such drawbacks, the present invention is installed in a trunk line for bidirectional transmission in a bidirectional CATV system for bidirectional transmission using a group-based method, and subscribers below this installation point. Having a trunk amplifier that outputs the upstream signal output to the upstream output terminal, and an upstream dedicated line that connects the upstream output terminal and the head end and transmits the upstream signal output from the main amplifier Is.
本発明においては、周波数配置を変えることなく、上り
回線の容量が拡大される。In the present invention, the capacity of the uplink is expanded without changing the frequency allocation.
本発明に係わる双方向CATVシステムの一実施例を第１図
に示す。同図において、５は上り回線出力端子６を有す
る幹線増幅器、７は上り専用回線、８は上り専用増幅器
である。第１図において第２図と同一部分又は相当部分
には同一符号が付してある。An embodiment of the bidirectional CATV system according to the present invention is shown in FIG. In the figure, 5 is a trunk amplifier having an upstream line output terminal 6, 7 is an upstream dedicated line, and 8 is an upstream dedicated amplifier. In FIG. 1, the same or corresponding parts as those in FIG. 2 are designated by the same reference numerals.
ヘッドエンド１は、アンテナで受信した信号（テレビ信
号およびFM信号）や必要に応じて入力されるビデオ信号
やデータ信号を伝送路に送出すると共に、各加入者から
送出される各種信号を受信して必要な処理を行なう。幹
線２はヘッドエンド１からサービス区域全体に信号を伝
達するための基幹伝送路であり、各加入者からの上り信
号も群別方式にて双方向伝送される。幹線増幅器３は幹
線２で生じるケーブル損失を等化する双方向の中継器で
ある。分配用入出力端子４は幹線２と加入者系との接続
点である。上り回線出力端子６を有する幹線増幅器５
は、幹線２におけるケーブル損失を等化し、下り信号を
下方の幹線２に送出すると共に、下方よりの上り信号を
上り回線出力端子６より送出し、上り専用回線７を通し
てヘッドエンド１に送る。上り専用回線７の損失は上り
専用増幅器８で等化される。The headend 1 sends out signals (television signals and FM signals) received by an antenna, video signals and data signals input as necessary to a transmission line, and receives various signals sent from each subscriber. And perform the necessary processing. The trunk line 2 is a trunk transmission line for transmitting a signal from the headend 1 to the entire service area, and an upstream signal from each subscriber is also bidirectionally transmitted by the group-based method. The main line amplifier 3 is a bidirectional repeater that equalizes the cable loss generated in the main line 2. The distribution input / output terminal 4 is a connection point between the trunk line 2 and the subscriber system. Main line amplifier 5 having upstream line output terminal 6
Equalizes the cable loss in the trunk line 2, sends a down signal to the down trunk line 2, sends a down up signal from the up line output terminal 6, and sends it to the headend 1 through the up line 7. The loss of the upstream dedicated line 7 is equalized by the upstream dedicated amplifier 8.
従って、幹線増幅器５より下方の加入者から送出される
上り信号は上り回線出力端子６から上り専用回線７を通
してヘッドエンドへ伝送され、幹線増幅器５より上方の
加入者から送出される上り信号は幹線２を通してヘッド
エンド１に伝送される。Therefore, the upstream signal sent from the subscriber below the main amplifier 5 is transmitted from the upstream output terminal 6 to the head end through the dedicated uplink line 7, and the upstream signal sent from the subscriber above the main amplifier 5 is the main line. 2 is transmitted to the head end 1.
上記の構成とすることにより、１幹線にて下り信号を分
配する加入者数を減らすことなく、１加入者当たりの上
り周波数帯域を拡大することができる。With the above configuration, it is possible to expand the upstream frequency band per subscriber without reducing the number of subscribers who distribute downlink signals on one trunk line.
以上説明したように本発明は、上り回線出力端子を有す
る幹線増幅器と上り専用回線とを用いることにより、上
り信号を幹線の一定区間毎に独立にヘッドエンドまで伝
送することができ、周波数配置を変えることなく、上り
回線の容量を拡大できる効果がある。As described above, according to the present invention, by using the trunk amplifier having the uplink output terminal and the uplink dedicated line, the uplink signal can be independently transmitted to the head end in each constant section of the trunk line, and the frequency allocation can be performed. There is an effect that the capacity of the uplink can be expanded without changing.
第１図は本発明に係わる双方向CATVシステムの一実施例
を示す系統図、第２図は従来の双方向CATVシステムを示
す系統図である。 １……ヘッドエンド、２……幹線、3,5……幹線増幅
器、４……分配用入出力端子、６……上り回線出力端
子、７……上り専用回線、８……上り専用増幅器。FIG. 1 is a system diagram showing an embodiment of a bidirectional CATV system according to the present invention, and FIG. 2 is a system diagram showing a conventional bidirectional CATV system. 1 ... Headend, 2 ... Trunk line, 3,5 ... Trunk line amplifier, 4 ... Distribution input / output terminal, 6 ... Uplink line output terminal, 7 ... Uplink dedicated line, 8 ... Uplink dedicated amplifier.
Claims (1)
向CATVシステムにおいて、 双方向の伝送を行なう幹線中に設置され、この設置点よ
り下方の加入者から送出された上り信号は上り回線出力
端子へ出力する幹線増幅器と、 前記上り回線出力端子とヘッドエンドとの間を接続して
前記幹線増幅器から出力された上り信号を伝送する上り
専用回線と を有することを特徴とする双方向CATVシステム。1. In a bidirectional CATV system that performs bidirectional transmission using a group-based method, an up signal transmitted from a subscriber below the installation point is installed in a trunk line that performs bidirectional transmission. A bidirectional system comprising: a trunk line amplifier for outputting to a line output terminal; and an uplink dedicated line for connecting the upstream line output terminal and a head end to transmit an upstream signal output from the trunk line amplifier. CATV system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61079193A JPH0779468B2 (en) | 1986-04-08 | 1986-04-08 | Interactive CATV system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61079193A JPH0779468B2 (en) | 1986-04-08 | 1986-04-08 | Interactive CATV system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62236289A JPS62236289A (en) | 1987-10-16 |
| JPH0779468B2 true JPH0779468B2 (en) | 1995-08-23 |
Family
ID=13683138
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61079193A Expired - Lifetime JPH0779468B2 (en) | 1986-04-08 | 1986-04-08 | Interactive CATV system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0779468B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4503771B2 (en) * | 2000-03-07 | 2010-07-14 | マスプロ電工株式会社 | Upstream signal amplifier and bidirectional CATV system |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6040070Y2 (en) * | 1978-06-16 | 1985-12-02 | ホーチキ株式会社 | Central monitoring device for CATV system |
| JPS5819087U (en) * | 1981-07-29 | 1983-02-05 | 株式会社日本アルミ | Upper bay window screen device |
-
1986
- 1986-04-08 JP JP61079193A patent/JPH0779468B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62236289A (en) | 1987-10-16 |
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