JPS6117439B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a subscriber line concentration system in a subscriber line exchange.

As subscriber line concentration methods in conventional subscriber line exchanges, there are a time division concentration method and a space division concentration method. In the time-division concentrator system, each subscriber line is accommodated in a time-division concentrator stage via an A-D converter and a DA converter, and then multiplexed and accommodated in a distribution stage. . Since A-D converters and D-A converters have high unit costs, a time-division concentrator system that requires a number of these converters equal to the number of subscriber lines generally becomes expensive. On the other hand, in the space division concentration system, individual subscriber lines are first accommodated in a space division concentration stage, and the concentration ratio differs depending on the subscriber type in the space division concentration stage. Since public subscriber lines are frequently used, they are concentrated into a smaller number of signal lines than the number of subscriber lines, such as 2:1. Each of the signal lines smaller than the number of subscriber lines is multiplexed via an AD converter and a DA converter, and then accommodated in a distribution stage. Therefore, although the number of converters can be reduced compared to the time-division concentrator system, the space-division concentrator stage must have a different configuration for each subscriber type and each subscriber circuit type. This generally complicates the overall system configuration. Also,
In connection with the fact that the control of the space division concentrator stage differs depending on the subscriber type and subscriber circuit type, there is an increase in call volume due to the addition of subscriber lines and increased frequency of use, and the introduction of new functions to subscriber circuits. It is difficult to perform service functions appropriately and economically by adding additions and trunks. As described above, both the conventional time-division concentration method and the space-division concentration method have problems.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to advantageously combine the functions of a space division method and a time division method in a line concentration system. It is possible to appropriately and economically increase the call volume due to expansion or increased frequency of use, and to add new functions to subscriber circuits or add service functions by adding trunks, and to increase the number of subscribers of different types. By accommodating the lines in space-divided concentrator stages with the same configuration, it is possible to simplify the overall system configuration, and furthermore,
- It is possible to reduce the cost by reducing the number of D converters and DA converters.

In the present invention, in a concentrating system in which subscriber lines are accommodated in a distribution stage, the subscriber lines are divided into a plurality of groups, at least a part of the plurality of groups is accommodated in a space division concentrator stage, and the subscriber lines are divided into a plurality of groups. The output of the space-division concentrator stage or the direct output from the subscriber line is connected to an interface section, and at least a part of the output of the interface section is accommodated in the time-division concentrator stage and then in the distribution stage. A subscriber line concentration system is provided in which signal lines that are not used are directly accommodated in the distribution stage.

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4.

In a first example of a line concentration system to which the line concentration method according to the present invention is applied, as shown in the block circuit diagram of FIG. 1, a subscriber 1 with a low call rate and a subscriber 1' with a high call rate are The space division concentrator stage 3 is connected to the space division concentrator stage 3 via the
In the system, subscriber lines are concentrated into fewer signal lines than the number of subscriber lines at a fixed line concentration ratio (for example, 2:1 to 4:1) regardless of subscriber type, and each signal line is connected to a subscriber circuit (not shown in the figure). ) and A-D and D-
After passing through the A converter 4, the signal lines corresponding to subscriber lines with a low call rate are connected to a time division concentrator stage 5, where they are condensed into fewer signal lines at a concentration ratio of, for example, 5:1, and then multiplexed. The signal lines connected to the multiplexing section 6 and corresponding to subscriber lines with a high call rate are directly connected to the multiplexing section 6 without being condensed. The multiplexed signal is accommodated in the distribution stage 7. In FIG. 1, subscriber circuit functions such as DC supply and 2-wire/4-wire conversion are not shown. In this example, a part of the digital side signal of the A-D and D-A converter 4 is directly connected to the multiplexing unit 6 without concentrating the signal, so that it is used for high-priority subscribers with a high call rate. This is particularly effective when

A second example to which the line concentration method according to the present invention is applied is shown in FIG. In FIG. 2, a subscriber 1 with a low call rate is concentrated to a space division concentrator stage 3 via a subscriber line 2, and in the space division concentrator stage 3, the subscriber line with a low call rate is concentrated at a certain concentration ratio (for example, 2 :1), the signal lines are concentrated into fewer signal lines than the number of subscriber lines with a low call rate, and each signal line is connected to a subscriber circuit (not shown) and A-D and D.
- connected to the time division concentrator stage 5 via the A converter 4;
Here, the signal lines are further concentrated into fewer signal lines at a constant concentration ratio (for example, 5:1), and then connected to the distribution stage 7 via the multiplexer 6. High call rate subscriber 1'
is directly sent to the multiplexing unit 6 via a subscriber circuit with a low call rate and a different subscriber circuit (not shown) and an AD and DA converter without undergoing space-division concentration or time-division concentration. After being connected, it is connected to the distribution stage 7. This second example is particularly effective when the number of high call rate subscribers is small because the high call rate subscribers are directly connected to the multiplexing unit 6 without being concentrated.

A third example to which the line concentration method according to the present invention is applied is shown in FIG. In a third example, a subscriber line 2 with a low call rate is concentrated at a constant concentration ratio by a space division concentrator stage 3, which connects a subscriber circuit (not shown) and an AD and DA converter 4. After that, the lines are concentrated by the time division concentrator stage 5 for low call rate subscribers and then connected to the multiplexing section 6 for low call rate subscribers, and the low call rate lines are directly connected to the low call rate lines without undergoing time division line concentration. Subscriber multiplexing unit 6
It is divided into those connected to the On the other hand, the high call rate subscriber line 2' is not subjected to space division concentration, and after passing through the subscriber circuit and the A-D and D-A converter 4', the high call rate subscriber line 2' has a high call rate like the low call rate subscriber line 2. There are those which are concentrated by the subscriber time division concentrator stage 5' and then connected to the high call rate subscriber multiplexing unit 6', and those which are directly connected to the high call rate subscriber multiplex without undergoing time division concentration. It is divided into those connected to section 6'. The multiplexing sections 6, 6' are connected to a distribution stage 7. In this third example, there are subscribers with a relatively high call rate among the subscribers with a low call rate, and there are subscribers with a relatively low call rate among the subscribers with a high call rate. Particularly effective.

A fourth example to which the line concentration method according to the present invention is applied is shown in FIG. In the fourth example, the subscriber line 2 with a low call rate is condensed by the space division concentrator stage 3 as in the conventional space division concentrator system, and then connected to the subscriber circuit for A-D and D-A conversion. The subscriber line 2' with a high call rate is directly accommodated in the distribution stage 7 via the multiplexer 6 without being subjected to time-division concentration.
As in the third example, after passing through the subscriber circuit and the A-D and DA converter 4' without undergoing space-division concentration, it is processed by the time-division concentration stage 5' for high call rate subscribers. There are two types: those that are concentrated and then connected to the multiplexing section 6' for high call rate subscribers, and those that are directly connected to the multiplexing section 6' for high call rate subscribers without time division concentration. ing. The multiplexing section 6' is also connected to the distribution stage 7. In this example, the subscriber type is 2.
This is particularly effective when it can be broadly classified into types.

According to the first example, since all subscriber lines are concentrated at a constant concentration ratio in the space division concentrator stage, it is sufficient to have fewer AD and D-A converters than the number of subscriber lines; Therefore, the cost of the entire system can be reduced compared to when using only the conventional time-division concentration method, and since the concentration ratio in the space-division concentration stage is the same for different types of subscribers, the configuration of the space-division concentration stage can be reduced. is simple, and it is possible to accommodate heterogeneous subscribers and add service functions more appropriately and economically than when using only the conventional space division concentration method.

According to the second example, there is no need to consider the effect of high call rate subscribers on traffic characteristics such as blocking rate in the space division concentrator stage 3, and therefore it is easy to add service functions and control increases in call volume. become.

According to the third example, subscriber lines with a relatively high call rate among subscribers with a low call rate can be directly multiplexed without undergoing time-division concentration, thereby increasing the efficiency of subscriber switching. can be increased. Furthermore, when there are a large number of high call rate subscribers, the number of high call rate subscribers can be appropriately increased by accommodating some of them in the time division concentrator stage 5'.

According to the fourth example, since the line concentration methods for low call rate subscribers and high call rate subscribers are different, addition of service functions, increase in call volume, etc. can be appropriately and economically controlled.

In the explanation of FIGS. 1 to 4, the subscribers 1 and 1' are described as being ordinary telephones, but they are not necessarily limited to this, and may be digital terminals. In the case of a digital terminal, the A-D and D-A converters 4 in FIGS. 1 to 4,
4' instead of electrical signal level, phase, polarity,
A digital signal interface circuit is used that performs necessary processing such as pulse width.

In addition, in FIGS. 1 to 4, the ratio of the time division line concentration stage 5 and the multiplexing section 6 that does not perform line concentration is appropriately selected depending on the type and number of connected subscribers and the type of subscriber circuit. can do.

As explained above, according to the present invention, based on the concept of advantageously combining the functions of the space division method and the time division method in the line concentration method, when there are multiple subscriber types, the subscriber line It is possible to appropriately and economically increase the call volume due to expansion or increase in frequency of use, and to add new functions to subscriber circuits or add service functions by adding trunks. By accommodating them in a space-divided concentrator stage with the same configuration, it is possible to simplify the overall system configuration, and furthermore, by reducing the number of AD and DA converters, the cost can be reduced. I can make it seem possible.

[Brief explanation of the drawing]

1 to 4 are block circuit diagrams of a line concentration system to which the present invention is applied, and are for explaining each embodiment of the line concentration system according to the present invention. 1, 1': Subscriber, 2, 2': Subscriber line, 3: Space division concentrator stage, 4, 4': A-D converter and D-
A converter, 5, 5': time division concentrator stage, 6, 6': multiplexing section, 7: distribution stage.

Claims (1)

[Claims] 1. In a line concentration system in which subscriber lines are accommodated in a distribution stage, the subscriber lines are divided into a plurality of groups, and at least a part of the plurality of groups is accommodated in a space division concentrator stage. , connecting the output of the space-division concentrator stage or the direct output from the subscriber line to an interface section, and storing at least a part of the output of the interface section in the time-division concentrator stage and then in the distribution stage; A line concentration method characterized in that signal lines that are not time-division line concentrated are directly accommodated in the distribution stage. 2 In the method described in claim 1,
A system characterized in that all of the subscriber lines are accommodated in the space division concentrator stage. 3 In the method described in claim 1,
What is a time-division concentrator stage in which at least a part of the digital side signal line obtained by connecting the direct output from the subscriber line to the interface section is connected to the signal that has passed through the space-division concentrator stage? A method characterized in that the line is connected to another time division concentrator stage and then accommodated in the distribution stage. 4 In the method described in claim 1,
All of the signal lines that have passed through the space division concentrator stage are directly accommodated in the distribution stage via the interface section, and at least part of the direct output from the subscriber line is routed through the interface section. A method characterized in that the line is stored in a time-division concentration stage and then stored in the distribution stage. 5. In the method set forth in any one of claims 1 to 4, when at least some of the plurality of groups handle analog signals, the corresponding interface section is converted from analog to digital. A method characterized by comprising a converter and a D-A converter. 6. In the system according to any one of claims 1 to 4, when at least some of the plurality of groups handle digital signals, the corresponding interface section is provided with the necessary functions. This method is characterized by having a digital signal interface circuit with