KR100442441B1 - Tap-off with adjustable tap value - Google Patents

Abstract

The present invention relates to a signal splitter connected to an end on a transmission line in a cable TV (CATV) coaxial distribution network. More particularly, a signal splitting signal from a trunk line to a subscriber side for a plurality of signal distribution systems in a cable broadcasting and public hearing system. The apparatus includes a plug-in type attenuator detachable from a control printed circuit board for adjusting a branch loss value of a signal input through the trunk line, and a control printed circuit board having a first socket to which the attenuator is mounted. It relates to a signal branch that bidirectional communication capable of bidirectional communication is adjusted.

The present invention is compatible with the pre-installed signal divider, and in the case of extending / extending the CATV network, even if the number of branching branches is increased by multiples, the same signal level without variation of the input / output levels can be realized. The purpose of the present invention is to provide a signal diverter whose branch loss is adjusted, and even when constructing a new CATV network, the diverter of various branch losses can be implemented according to the site situation by using a signal diverter according to the present invention. Since it can easily cope with the change of capacity according to the planning time and operation time of transmission network, and can cope quickly with low cost and little effort, it is possible to manufacture various models for each quarter loss and install them according to the situation. Compared to the breakthrough.

Description

Signal tap-off with branch loss {Tap-off with adjustable tap value}

The present invention relates to a signal divider for distributing a broadcast signal provided from a cable broadcasting station to a plurality of output stages, and more particularly, a signal divider for dividing a signal from trunk lines to subscribers for a plurality of signal distribution systems in a cable broadcasting and public hearing system. A plug-in type attenuator detachable from a control printed circuit board for adjusting a branch loss value of a signal input through the trunk line, and a control printed circuit board provided with a first socket to which the attenuator is mounted. It relates to a signal divergence that is characterized in that the branch loss is adjusted.

In general, comprehensive cable broadcasting and cable broadcasting (hereinafter referred to as 'CATV') that are serviced deliver a broadcasting signal through a wired network. That is, the broadcast signal provided by the CATV local broadcasting station is transmitted to the final viewer while passing through various optical transmitters, amplifiers, splitters, diverters, and the like as shown in FIG. Therefore, in the CATV system, the signal splitter (tap-off or tap unit) and the signal divider play important roles, and if they are bad, ghost phenomenon, screen distortion, loss of transmission information, channel In other words, the signal branch divides the broadcasting signal from the trunk line to the branch line and the branch line to the subscriber end in the CATV and television public hearing system. In the communication HFC network (Hybrid Fiber coaxial network), the down stream from the head end to the subscriber through the trunk and branch lines, and the up stream from the subscriber to the central control device (CMTS). In detail, the signal reception level of the subscriber end has a proper range with respect to the downlink signal input through the trunk line and the branch line. On the other hand, the signaling branch serves to finally determine the subscriber station signal reception level according to the tap loss value. In addition, the transmission level of the uplink signal from the subscriber station in the bidirectional communication is determined by the subscriber station. And the Central Control Unit (CMTS) maintain the proper level by interworking with each other.However, the signal diverter that transmits the upstream signal to the Central Control Unit also adjusts the transmission level of the subscriber station based on the tap loss value. Conventional signal dividers are generally divided into 1 quarter, 2 quarter, 4 quarter, 8 quarter, 16 quarter, etc. according to the number of branch terminals, and again according to the number of terminals of branch branches. And branch loss in 3dB steps such as 14, 17, 20, 23, 27 decibels (dB), and therefore, in the configuration of communication networks including broadcasting networks such as CATV, Design and construct the signal diverter by determining the transmission / reception level of the down stream and upstream according to the specifications such as the existing loss value. Therefore, the broadcaster such as CATV and the operator and builder of the communication network In order to meet the above mentioned conditions, it is necessary to purchase, construct, and hold various kinds of tapers according to the number of branch terminals and many kinds of tapers having various branch loss values. There is a burden to produce and sell the product as an independent model and to keep the inventory.

Recently, with the activation of the Internet, CATV has developed into a two-way digital broadcasting capable of up-and-down communication that provides various broadcasting and text and information service functions using broadband characteristics, and subscribers are continuously increasing.

However, when the number of CATV subscribers increases due to the characteristics of CATV that transmits a broadcast signal by wire, additional work such as installing a separate line and amplifier for new subscribers and implementing a signal distribution / branch is required.

In particular, when a new subscriber is added to an area where a CATV signal transmission system is already installed, there is a situation in which the subscriber's request for joining a CATV is increasing due to lack of installation space for additional equipment and insufficient capacity of a branch. Occurs.

That is, the conventional CATV signal transmission system has an extra idle state of the receiver (television) output terminal of the existing subscriber connected to the pre-installed signal divider or the final signal divider in order to supply a signal to a new subscriber additionally generated while already installed. A separate signal branch was further connected to the branch terminal, and each branch terminal of the additionally installed signal branch was connected to a new subscriber. However, in this case, the signal transmission system already installed is set so that the output of the amplified signal from the amplifier can be maintained at the time of system construction. When the receiver of the new subscriber is connected to the optimized signal transmission system, In addition, the output of the signal transmitted to the receiver (television) of all subscribers, including the new subscriber, becomes weak, which causes a problem of failing to transmit a stable signal. In addition, the conventional signal splitter is designed to have a constant branch loss. According to the signal level and the number of branches of the furnace, tap value is selected and used. Therefore, when constructing a new CATV network, considering the expected number of users and distribution area by user, the amplifier, divider, The capacity and quantity of turnouts, etc., should be determined. In the case of establishing a construction plan and establishing a CATV network based on these expectations, there were problems in that excessive facility investment was made due to uncertainty in acceptance prediction, or, conversely, excessive facility investment was required, which required additional expansion work later. As shown in FIG. 2, when the broadcast signal transmission system is already provided and the CATV subscriber connects his / her receiver 3 to the tap-changer 10 and newly connects the tap-off while watching CATV, the signal output level is increased. Existing tap-offs 10 do not have the function of amplifying their own signal levels as shown in Fig. 3, so it is difficult to add additional tap-offs unless an amplifier is provided. Since the device is a passive type that passes the signal, there is no function to amplify the signal. It is currently used for the two-way communication and the cable broadcasting by selectively installing the noise filter and the high pass filter.

Therefore, the additional troublesome and costly problem of installing a new amplifier to amplify the signal on the additionally connected coaxial cable occurs, and in the worst case, it is difficult to further expand due to the space problem.

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above, and the conventional signal diverter is implemented as a model by replacing various types of branching according to the number of branch terminals and signal branching having various kinds of branching loss values for each signal branching. In this case, in the case of expanding / extending CATV network by adding an additional branch at the end of the already installed branch, the bidirectional branching system in which branching loss is easily adjusted can be easily adjusted in preparation for expansion / expansion. In addition, the present invention provides a signal divider that adjusts the branch loss that can compensate the loss of the signal level so as to realize the same signal level without changing the input / output level even if the number of branching branches is increased in multiples. The aim is to provide compatibility with signal splitters that act as passive components on existing CATV systems.

Another object of the present invention is to replace the existing CATV network or to newly add the CATV network, and to actively replace the cost of receiving the broadcast signal generated between the time of the CATV network construction and the actual use, and to replace it without expensive cost. It is to provide a bidirectional signal splitter with adjustable branch loss.

1 is a block diagram of a general cable broadcasting signal transmission system.

2 is a schematic diagram of a conventional cable broadcasting signal transmission system.

3 is a block diagram of a conventional signal splitter used in a cable broadcasting signal transmission system.

4 is a block diagram of a signal branch which is an embodiment of the present invention.

5 is a schematic diagram of a cable broadcasting signal transmission system employing a signal branch which is an embodiment of the present invention.

6 is an exploded perspective view of a signal branch which is an embodiment of the present invention.

<Description of Symbols for Major Parts of Drawings>

1: cable station 2: two-way amplifier

3: subscriber receiver (TV) 10: conventional signal splitter

11: input terminal 12: output terminal

13, 15: branch core 14: jumper, filter

16: branch terminal 100: signal branch which is an embodiment of the present invention

110: attenuator 120: adjustment module

121: power supply unit 130: control printed circuit board

131: first socket 132: second socket 141: case body 142: case base 143: case cover

If described with reference to the accompanying drawings, a specific example of the present invention.

Referring to Fig. 4, there is shown a signal diverter whose branch loss is adjusted in accordance with the present invention.

As an exemplary embodiment of the present invention, a branching switch with a branching loss is adjusted in a branching system that divides signals from trunk lines to subscribers for a plurality of signal distribution systems in a cable broadcasting and public hearing system, as shown in FIG. A control printed circuit board having a plug-in type attenuator 110 that can be attached to and detached from a control printed circuit board and a first socket 131 to which the attenuator 110 is mounted. In this case, the attenuator for adjusting the branch loss value can be used as a selective or variable attenuator. That is, a signal divider for which branching loss is adjusted according to another embodiment of the present invention is a selective pad type attenuator or branching loss in which the attenuator selects and mounts one of a plurality of pad type attenuators having a preset branching loss value. It is characterized in that the variable attenuator whose value is continuously changeable, i.e., the detachable attenuator has a desired capacity in a plurality of pad type attenuators provided according to a predetermined branch loss value according to the user's request or the characteristics of the installation site. It is possible to select and use among a selectable pad type attenuator which is selected and mounted on the first socket and a variable attenuator which can be continuously adjusted to a desired branch loss value after being mounted on the first socket. As a specific example of the invention, the signal loss for which the branching loss is adjusted is the two types of attenuators. By using this, it is possible to implement a desired branch loss value in one model, which requires a signal divergence as each independent model having branch losses of conventional 8, 11, 14, 17, 20, 23, 27 dB, etc. At the same time, the divergence loss of the signal divider is increased by 1 dB for the selective pad type attenuator or finer adjustment for the variable type attenuator. It is possible to implement in the model, that is, the branch loss is not fixed like the conventional signal diverter, but the branch loss value can be adjusted freely according to the use environment, and it is designed, constructed, manufactured and sold, and networked. Of complex models when using conventional signal diverters with different divergence losses (eg, 2nd quarter) 8/11/14/17/20/23/27 dB, 4/11/14/17/20/23/27 dB, 8/14/14/17/20/23/27 dB By applying a single branch loss value for each branch terminal, up to 7 or more deformation models for each item were compressed into one representative model, which was designed to achieve breakthrough convenience in design, construction, and maintenance from the user's point of view. In addition to providing ease of management in production, inventory, and purchase due to the complex model of the company, the burden of inventory maintenance is reduced, and in the case of a manager operating a cable broadcasting network, inventory management and purchase management of maintenance products for the network In addition, the inventory burden can be minimized, and the amount of detachable attenuators can be minimized to facilitate the level fluctuations in the operation of the network. Caused by In addition, since the attenuator is made of a plug-in type which is detached and attached to the first socket, there is an advantage that it can be easily replaced and repaired in case of a failure. The branch loss value is variously determined according to the quantity of the signal and the level of the signal. The branching device according to the present invention is characterized in that the attenuator is configured such that the branching loss is adjustable to meet the various requirements. Even when the CATV network is designed by calculating the most accurate capacity at the time of designing, the situation may change during the actual construction and the branch loss value required by the signal branch can be changed. The branch loss of the selective pad attenuator is determined to match the determined capacity at the time point. The attenuator can be installed in the socket, or the branch loss value of the variable attenuator can be adjusted appropriately to construct the CATV network with the optimum capacity. Capacitance fluctuations can be dealt with by replacing the optional pad attenuator. In addition to the branch loss value adjustment function of the signal branch which is an embodiment of the present invention, the loss compensation function is as follows. As shown in FIG. 3, after the broadcast signal coming in through the input terminal 11 is branched from the branch core 13, the jumper 14 or the filter 14 and the plurality of branch cores 15 are passed through. Since it is transmitted to each user receiver through a plurality of branch terminals 16, if a change factor in the facility capacity of the CATV network as described above, an appropriate response is Although it is difficult, when using a signal diverter whose branching loss is adjusted, the branching loss can be adjusted by itself, and the loss compensation can be achieved by amplifying the signal level. The control module is mounted in a plug-in type detachable to the control printed circuit board in the tap-off, the adjustment module 120 for adjusting the signal passing through the attenuator, and the control module 120 is located on the control printed circuit board is mounted The control module further comprises: an amplifier module for compensating and amplifying a loss of the signal passing through the attenuator or a jumper module or the signal passing through the signal passing through the attenuator as it is. The filter module for filtering the signal passing through the attenuator can be selectively installed. The.

As shown in FIG. 6, the signal divergence of which branch loss is adjusted, as shown in FIG. 6, is divided into a case body including a case body 141, a case base 142, and a case cover 143 as shown in FIG. A distribution unit 160 having terminals 16, a main unit having branch cores for distributing signals to the branch terminals (not shown in FIG. 6), and a branching unit as shown in FIGS. An attenuator 110 for attenuating the input signal to an appropriate level, an adjustment module 120 for adjusting the signal transmitted from the attenuator 110, the attenuator 110 and the adjustment module 120 is mounted, the main portion The control printed circuit board 130 is provided is made. In addition, as shown in FIG. 4, a power supply 121 (not shown in FIG. 6) for driving the adjustment module 120 is included.

At this time, the adjustment module 120 is mounted to the second socket 132 provided in the control printed circuit board 130 as a plug-in type, as shown in FIG. Therefore, it is possible to change the type of adjustment module as needed. That is, the signal divider of the present invention selects the adjustment module in various ways and according to the business purpose of the network operator, in the case of using the jumper module, the manual signal changer is used. (Passive type tap-off with high pass filter) or Passive type tap-off with high filter In the case of using an amplifier module, it can be used as an active type tap-off, i.e., a conventional signal divider is a passive type that passes a signal. Most signal splitters are equipped with only an up-noise filter and a high pass filter, which are used for two-way communication and cable broadcasting. The signal splitter of the invention not only performs these basic functions, but also uses a plug-in type amplifier module that can amplify the signal in a second socket. It is possible to actively adjust the loss value with respect to the increase in the number of branch terminals, the change in the loss in the branch loss value, etc. that occur basically in the device. When the amplifier module is selected and used as the adjustment module 120, The signal divider of the present invention serves as an active tap-off, which inputs through the trunk and branch lines, and then outputs a signal whose branch loss is adjusted by the attenuator as shown in FIG. After separating the band upward and downward while passing through the separator 123, the signal is lost while passing through an amplifier that amplifies the signal. Compared to the conventional passive signal divider used to pass the signal without band separation of the downlink signal and the uplink signal as shown in FIG. 3, the adjustment module (shown in FIG. In the case where the amplifier module is selected and used, the signal divider according to the present invention divides the signal passing through the band separator 123 into upward and downward directions (5 to 42 MHz in the upward direction and 54 to 750 in the downward direction). Signals are passed by dividing bands while providing equal amplifier capacity for each band after MHz. This means that in the case of bidirectional amplification, the downlink signal and the uplink signal must have separate paths, This is because the loss of the downlink signal band and the uplink signal band occurs equally when the branch loss value is adjusted by the loss adjustment function. This is because the downlink signal and the uplink signal must pass through separate paths in order to prevent the amplification of unnecessary frequency band signals. The signal divider, which is an embodiment of the present invention, in which an amplifier module is selected and used as the adjustment module 120. In this case, the objective of the present invention is to compensate for the loss required for securing the scalability (expansion of the branch terminal) compared to the conventional passive signal branch and does not provide any further amplification. In addition, the amplifier module selected as the adjustment module 120 amplifies the signal only between the signal from the trunk to the subscriber (downward signal) and the signal from the subscriber to the trunk (upward signal), the input terminal 11 output terminal of the signal splitter The signal passing through (12) is not amplified, which is different from the original amplifier installed on the line, and the role of the unit in the system limits its role as a passive element rather than an amplifier. The amplifier module selected as the adjustment module 120 of the signal divider of the present invention is designed to be amplified within a range that does not affect the noise figure of the entire system. The reference for gain is defined by the conventional passive signal divider. It provides amplification by the additional loss incurred in expanding the number of branch terminals (1, 2, 4, 8, 16 terminals, etc.) to each multiple (2, 4, 8, 16, 32, etc.). That is, in the present invention, the signal branch of the two branch terminal has the same branch loss as the signal branch of the passive one branch terminal, and in the present invention, the signal branch of the four branch terminal has the same branch loss as the signal branch of the passive two branch terminal. In the present invention, the signal branch of the eight branch terminal has the same branch loss as that of the passive four branch terminal, and in the present invention, the signal branch of the sixteen branch terminal has the same branch loss as the signal branch of the passive eight branch terminal. The signal divergence of equals the same branch loss as the signal divergence of the passive 16 branch terminal. It can be installed and through this, it is possible to connect subscribers of multiples compared with the conventional passive signal branch, and at the same time In order to provide compatibility to expand subscribers in multiples while maintaining the same input and output levels from conventional passive signal splitters. In general, the output level of an uplink signal transmitted from a subscriber in a bidirectional data communication is a downlink signal. If there is a change in the output level of the downlink signal (input to the upstream signal), the subscriber station automatically recognizes it and then increases the level of the uplink signal by the downlink signal. In this case, the size of the uplink signal reaching the network operator's central control unit (CMTS) will be out of the default setting, which may impede bidirectional communication. Therefore, as mentioned above, ensuring compatibility with existing signal splitters is a solution to this problem. If the amplifier module of the signal splitter of the present invention does not have the above-mentioned compatibility, the user's convenience is reduced by that much. Due to the establishment and application of a new standard by a new device, the breakthrough of the signal divider of the present invention will be halved. In addition, when there is no need for amplification, only a jumper module or a proper signal that merely passes through is required. It is possible to install the filter module to the second socket for use. Such replacement work can be determined and used at the time of installation of the signal divider, and the type of adjustment module can be determined according to the change of ambient conditions during use. It is possible to replace the module. In particular, when using a jumper module or a filter module, the same effect as that of a conventional signal splitter can be obtained.In other words, when a separate compensation and amplification of the signal level is not necessary, a jumper module is installed instead of an amplifier module. Or, it is configured to serve as a diverter as a passive element by mounting a filter module.

By utilizing the plug-in type attenuator and bidirectional amplification module with adjustable branch loss of the present invention, a single model can be efficiently replaced by a single model in various field situations. Compared to this, it can reduce enormous production cost and can be installed immediately according to the situation when constructing the network line, which is a revolutionary invention. Also, by modularizing the components, maintenance of CATV network is easy, and new Even when building a CATV network, it is possible to actively and flexibly cope with changes in capacity according to the actual point of use of the CATV network with low cost and little effort, in particular, compatibility with conventional signal splitters. Extend subscribers by simply replacing devices in already installed networks through The effect is to increase the sex in multiples. This means that if additional subscribers occur in the existing network without additional subscriber connections, the network operator must construct a new network, and for this, a huge cost similar to that of the existing network must be spent. On the contrary, when the signal divider of the present invention is replaced with the conventional passive signal divider, the same level without changing the input / output level can be realized while providing the subscriber expandability of multiples. When the CATV network is configured by using a signal adjuster whose loss is adjusted, it is not necessary to install an additional amplifier for the increase of subscribers of the CATV network. It is possible.

In addition, since the level of the signal output is not reduced even by the addition of a brancher according to the increase in subscribers, there is an effect of providing a high quality broadcast.

The cost of doubling subscriber scalability by replacing the signal splitter of the present invention with a passive signal splitter in an already installed network is the cost of replacing the conventional passive signal splitter with the signal splitter of the present invention and the cost of the present invention. It adds only the additional cost due to the splitting cost when the purchase cost of the signal branch and cell division is required (optional), resulting in a cost reduction of about 80 ~ 90% compared to the new network construction. The city's cost saving effect increases the scalability of the subscriber connection by 200% compared to the conventional signal branch by providing the amplifier function to compensate the signal as well as the convenience of the branch loss adjustment. There is an effect to reduce over.

Claims (6)

In a signal branch that divides signals from trunk lines to subscribers for multiple signal distribution systems in cable broadcasting and public hearing systems A plug-in type attenuator detachable to a control printed circuit board for adjusting a branch loss value of the signal input through the trunk line; A control printed circuit board having a first socket on which the attenuator is mounted; An adjustment module mounted on the control printed circuit board as a plug-in type detachable and adjusting a signal passing through the attenuator; A second socket located on the control printed circuit board and mounted with the adjustment module; and A power supply for driving the adjustment module; Including; The attenuator is a selective pad type attenuator for selecting and mounting one of a plurality of pad type attenuators having a preset branch loss value or a variable attenuator whose branch loss value can be continuously changed, The adjusting module is one of an amplifier module for compensating and amplifying the loss of the signal passing through the attenuator, a jumper module for passing the signal passing through the attenuator as it is, or a filter module for filtering the signal passing through the attenuator. The signal diverter with which branching losses are adjusted. delete delete delete delete delete