JP2002199376A - Information communication network utilizing catv - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use a down line having excess channels and to construct a bidirectional communication network having large capacity by transmitting an up electric signal from a subscriber's information communication terminal by using down signal frequency, transmitting the signal from a return communication line installed in the most downstream terminal end part to a head end part and receiving the signal by the head end part. SOLUTION: An output signal from a base station transmitter 11 is connected by a tap-off part 6 connected to the way of a CATV network 4 and connected to a subscriber's information terminal 8 directly or through a distribution antenna 7. A transmission signal to which the frequency of a down direction is allocated is transmitted from the terminal 8, connected to the CATV network 4 through the antenna 7 and the tap-off part 6, transmitted up to the most downstream side of the CATV network 4, and received by a base station receiver 12 through the terminal stations 14, 15 of an optical communication line 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

2. Description of the Related Art When configuring an information communication network using a CATV network, the frequency band in the upstream direction among the frequency bands allocated to the CATV network is limited from 10 MHz to 54 MHz. 30MHz
However, there is a problem that the capacity of the upstream communication line is insufficient due to the dominant ingress noise. In the information communication network using the CATV network according to the present invention, since the upstream line of the CATV network is provided outside, it is effective to compensate for the shortage of the upstream line.

[0002]

2. Description of the Related Art FIG. 2 is a diagram showing a configuration of a conventional CATV network. In FIG. 2, (1) is a head end portion,
(2) CATV transmitter, (3) mixer, (4) coaxial cable or optical cable, (5) bidirectional amplifier, (6) tap-off, (5) tuner, (6)
Is a TV receiver. In the conventional CATV network, 1
Use about 0 to 54 MHz, 70 to 450 MH downstream
Although z is used, in the frequency band of 30 MHz or less, the influence of ingress noise is large and the application is limited.
MHz). A bidirectional amplifier (5) for extending a signal reach separates an upstream direction and a downstream direction according to a frequency band, an amplifier in the upstream direction amplifies in the direction of the head end section (1), and an amplifier in the downstream direction downstream. In order to amplify the signal in the direction of the tuner (5), the signal in the upstream direction must always use the channel in the upstream direction. Some existing CATV networks are provided only with facilities for transmitting data in the downstream direction. In such a case, bidirectional information communication has to be abandoned.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to eliminate these drawbacks, and transmits an upstream electric signal from a subscriber information communication terminal at a downstream signal frequency,
By transmitting to the head-end unit via the optical communication line installed at the most downstream terminal unit and receiving it at the head-end unit, it is possible to use a downstream line with a sufficient number of channels and to establish a large-capacity bidirectional communication network. Can be configured.

[0004]

According to the present invention, a signal is transmitted through an upstream optical line connected to the most downstream side of a CATV network, and a signal transmitted by a subscriber is received at a head end. Downlink channels other than uplink frequencies that are susceptible to interference can be used.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, (1) is a head end portion,
(2) a CATV transmitter, (3) a mixer, (4) a CATV network using a coaxial cable or an optical cable,
(5) is a bidirectional amplifier, (6) is tap-off, (5) is a tuner, (6) is a CATV receiver, (7) is a distributed antenna, (8) is a subscriber information terminal, and (11) is information communication. (12) is a base station receiver for information communication, (13) is a return optical communication line, (14) (1)
Reference numeral 5) denotes a terminal station of the return optical communication line (13). CATV
It is assumed that the network (4) uses a frequency band of 70 to 450 MHz in the down direction. The CATV transmitter (2) and the base station transmitter (11) are respectively assigned different frequency bands within the above band, and their transmission outputs are mixed by a mixer (3) and connected to a CATV network (4). ,
On the way, the signal is amplified by a bidirectional amplifier (5) to compensate for the attenuation of the CATV network (4), and is transmitted to the most downstream of the CATV network. Transmission output signals from the base station transmitter (11) are combined by a tap-off (6) connected in the middle of a CATV network (4), and are directly or via a distributed antenna (7) to a subscriber information terminal ( 8) Connected to the receiver. The transmission signal from the subscriber information terminal (8) contains CA
A frequency in the downward frequency band of 70 to 450 MHz of the TV network is allocated and coupled to the CATV network (4) via the distributed antenna (7) via the tap-off (6),
The signal is transmitted to the most downstream of the CATV network, and is received by the base station receiver (12) via the terminal stations (14) and (15) of the return optical communication line (13). Thus, even when there is no upstream line of the CATV network or the capacity is insufficient,
With the information communication network of the present invention, a high-speed and large-capacity information communication network required for Internet communication or the like can be realized.

In the above description, the optical communication line is used as the return communication line, but the present invention can be realized by using other wired communication lines or wireless communication lines. The frequency band in the return communication line can be selected independently of the frequency band of the CATV network.

[0007]

As described above, the present invention can realize a large-capacity bidirectional communication even in a CATV network.

[Brief description of the drawings]

FIG. 1 is a structural diagram showing one embodiment of the present invention.

FIG. 2 is a structural view showing a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Head end 2 CATV transmitter 3 Mixer 4 CATV network by coaxial cable or optical cable 5 Bidirectional amplifier 6 Tap-off 7 Tuner 8 CATV receiver 9 Distributed antenna 10 Subscriber information terminal 11 Base station transmitter for information communication 12 Information Base station receiver for communication 13 Return optical communication line 14, 15 Terminal station of return optical communication line (13)

Claims (3)

[Claims] In a one-way or two-way CATV network, a base station transmitter for information communication installed at a head end of the CATV network or a node of an optical cable, and a transmission output signal from the base station transmitter are transmitted to a CATV network. A mixer for mixing with the signal, and a CAT connected to the mixer
A plurality of tap-offs provided at intervals in the V network; a subscriber information communication terminal connected to the tap-off directly via a cable or via a distributed antenna;
A return communication line provided between the most downstream terminal of the ATV network and the head end, and a base station receiver for information communication connected at the head end side terminal station of the return communication line. The transmission output signal of the base station transmitter is directed to the distributed antenna or the receiver of the subscriber information communication terminal via the tap-off using the first band of the frequency allocated in the downlink direction of the CATV network. The transmission output signal transmitted from the subscriber information communication terminal or the transmitter of the distributed antenna is transmitted in the downstream direction of the CATV network through the tap-off using the second band of the frequency allocated in the downstream direction of the CATV network. An information communication network using a CATV network, which is transmitted and transmitted to the base station receiver via the return communication line connected to the most downstream side. Click 2. The information communication network using a CATV network according to claim 1, wherein said return communication line is a wired communication line, a wireless communication line, an optical communication line, or a combination thereof. 3. The CATV network according to claim 1, wherein said return communication line is connected to a base station receiver for information communication at a second head end. Information communication network using