JPS6046919B2 - Distributor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a distributor in a digital exchange, and more particularly to a distributor for accommodating a plurality of time-division multiplexed communication paths on a highway in a distributed manner in a plurality of communication path switch units.

A call path switch in a large-scale exchange is usually constructed using a plurality of relatively small capacity switch units.

General configuration methods include a method in which switch units are connected in multiple stages, and a distributed method in which each switch unit is treated as if it were an independent exchange.

Whichever method is adopted, it is important to improve the traffic characteristics of the call route switch as a whole and to switch units when calls are concentrated on a specific route. Due to the need to balance the load between ports, it is desirable to distribute and accommodate the lines of each route in a plurality of switch units. FIG. 1 shows an example of the configuration of a distributed communication path switch.

30, 40, and 50 are switch units, respectively.

14 | 24 | 15125, 16, 26 are incoming highways to each switch unit, 31, 32, 41,
Reference numerals 42, 51, and 52 are output highways exiting from each switch unit.

Reference numeral 60 denotes an inter-unit switch for diverting a call to another switch unit when a call bus cannot be set within a single switch unit.

61, 62, 63 are switch units 30, 40, 50
It is a junker going from 64 to the inter-unit switch
, 65, and 66 are junkors extending from the inter-unit switch 60 to the switch units 30, 40, and 50.

10, 20 are distributors, 11, 12, 13, 21,
22 and 23 are highways on which each route line is multiplexed.

Each communication path on highways 11, 12, and 13 is connected to a distributor 10.
The communication paths on the incoming highways 14, 15, 16 and on the highways 21, 22, 23 are distributed by the distributor 20 onto the incoming highways 24, 25, 26, respectively, and the switch units 30, They are distributed and accommodated in 40 and 50. FIG. 2 shows an example of the configuration of a distributor, in which the communication path section of the distributor 10 consists of a gate matrix,
, 12, 13, a predetermined gate 10
1,102,103,104,105,106,107
, 108, 109, the switching operation is realized.

The call retention memory 70 designates which gates are to be closed in each time slot. 71, 72, 73, 7
Control lines 4, 75, 76, 77, 78, and 79 are used to transmit commands from the call holding memory 70 to each gate.

FIG. 3 shows a conventional example of a path holding memory.

In the figure, 80, 84, and 85 are memory units provided corresponding to the input highways to the distributor. Each unit 80, 84, 85 has a holding memory 81 that stores the gate number to be closed in each time slot within one frame 6.
, an address counter 83 that increments every time slot.
and a decoder 82 which produces from the contents of memory 81 a control signal to the gate to be closed. The distributor is functionally a semi-fixed switch, as there is no need to change the exchange connection pattern each time a call occurs or ends, unlike a normal switch.

Furthermore, the distribution of highway communication paths entering the distributor does not need to be done in units of a very small number of lines, but is usually done in units of an appropriate number of lines. Therefore, as shown in Fig. 4, if the number of communication paths in one highway frame is Mnl, and the number of lines in the distribution unit is m, then during normal operation without changing the distribution pattern, the connection pattern of the distributor is teeth,
The pattern of the first n time slots is m within one frame.
It is enough to repeat it several times. In other words, in response to requests only during steady operation, it is only necessary to prepare the call holding memory for n time slots. Therefore, each memory unit 80, 84, in the call holding memory 70 of FIG.
The holding memory 81 in 85 has a capacity only for n time slots. The number of bits of one memory word is [10 bits 1''], assuming that the number of output highways from the distributor is 1''. However, [ ] is a Gauss symbol, and [10g2Y] is
It means the smallest integer greater than 10 and 1''. Let W be the number of bits required for the entire call holding memory 70, where l is the number of highways entering the distributor.

However, if the holding memory 81 is prepared for only n time slots, changing the contents of the holding memory 81 for one time slot will automatically change the connection pattern for m time slots, assuming the number of lines in the distribution unit is m. It will change at the same time.

Generally, changes in the connection pattern of a distributor due to an increase in the number of circuit lines or an increase in the number of call switch units must be made online while the exchange is in operation. Therefore, since the number of highways entering the distributor is 1, it is necessary to completely block at least 1 m of communication paths before changing the connection pattern. Since 1m is usually expected to be a fairly large number, a fairly long pre-blocking period is required to block all of them, and the deterioration of the connection quality of the exchange during this period cannot be ignored. .

By the way, if the capacity of the holding memory 81 in each memory unit 80, 84, 85 is prepared for Mn time slots, the connection pattern can be changed in units of one time slot, so the connection when switching the connection pattern can be changed. It is possible to prevent quality deterioration.

In this case, the required capacity W1 of the holding memory 70 is as follows. However, according to this method, m times the amount of memory normally required is prepared just for the necessity of changing the connection pattern, and as the number of lines per distribution unit (m) increases, memory becomes extremely wasteful. Will be using it.

Therefore, the present invention aims to improve the above-mentioned drawbacks of the prior art, and its purpose is to improve the memory capacity without significantly increasing the amount of memory.
Moreover, it is an object of the present invention to provide a distributor that allows the connection pattern to be changed in units of one time slot.

A feature of the present invention for achieving this object is that the present invention includes a communication path section consisting of a gate matrix, and a communication holding memory that controls each gate of the matrix for each time slot within one frame, In a distributor in which communication paths on a highway that have been divided and multiplexed are distributed and accommodated in a plurality of communication path switch units, the holding memory has a capacity of one frame solution (m is the number of lines in a distribution unit) on the highway. A plurality of memory units provided corresponding to an incoming highway or an outgoing highway of a distributor consisting of two systems of a first holding memory and a second holding memory that circulate m times in one frame, and a communication path within one frame on the highway. a circular memory that circulates once per frame with a capacity equal to the number of memory units, and specifies either the first holding memory or the second holding memory in each memory unit; and a changeover switch for switching between the holding memory and the holding memory, and during normal operation, the connection pattern is stored in at least one of the first holding memory or the second holding memory, and the circulation memory stores the connection pattern in the first holding memory or the second holding memory having the connection pattern. When a memory is specified and the connection pattern is changed, the new connection pattern is stored in a holding memory that is not specified by the circulation memory, and the first or second holding memory is selected by the changeover switch according to the specification of the circulation memory. It's in the container.

Examples will be described below with reference to the drawings. FIG. 5 shows an embodiment of the call holding memory in the distributor according to the present invention, and since the configuration of the gate matrix is the same as that in FIG. 2, the embodiment will be explained using FIG. 2 and FIG. 5. .

In the figure, 80, 84 and 85 are memory units provided corresponding to the incoming highways 11, 12, 13 or the outgoing highways 14, 15, 16 of the distributor, and the memory unit 80 specifies the closing gate on the highway 11. is,
Similarly, the memory unit 84 specifies a closing gate on the highway 12, and the memory unit 85 specifies a closing gate on the highway 13.

The memory unit 80 has two systems of holding memories 90 and 91. Reference numerals 92 and 93 are address counters for the memories 90 and 91, respectively, which increments by one address every time slot.

Memories 90 and 91 have a capacity of n words, and address counters 92 and 93 circulate m times in one frame. 9
4 and 95 are decoders for determining the gate to be closed from the contents of the words read from the memories 90 and 91.

96 is a switch for connecting only the signal from one of the two decoders 94 and 95 to the control lines 71, 72, and 73.

97 and 98 are memory units 8 corresponding to the switch 96;
4, 85, the memory units 84, 8
5 is also assumed to have the same configuration as the memory unit 80.

99 is a random access memory having a capacity for one frame, that is, Mn words, and 100 is an address counter.

The address counter 100 increments by one address in one time slot and cycles exactly once in one frame. memory 99
One word consists of one bit, and in each of Mn time slots within one frame, each memory unit 80, 84, 8
Two systems of random access memory 90, 91 in 5
Specify which system is used to control the call matrix. That is, the switches 96, 97, and 98 are switched in accordance with the contents of the word read from the memory 99 for each time slot.

A bus 200 is used to update the contents of the memories 90, 91, and 99 from a control system external to the call holding memory 70.

In this embodiment, for the sake of explanation and convenience, the number of highways entering the distributor is three and the number of memory units is also three. However, the distributor according to the present invention is not limited to this. Of course, this is not something that can be done. With the above configuration, during normal operation other than when changing the connection pattern, the connection pattern is held in at least one of the holding memories 90, 91, which exist in two systems in each switch unit 80, 84, 85, and is circulated. The memory 99 stores a holding memory 90 or 91 corresponding to the connection pattern in all Mn time slots within one frame.
Either is specified.

In this case, the memory of the system not specified by the memory 99 can be used as a backup system in case of a failure in the active system. When changing the connection pattern, store the new connection pattern after the connection change in the memory on the side that is not being used at that time.

In such a state, if the end of a call is monitored for each time slot and the contents of the address in the memory 99 corresponding to that time slot are updated sequentially from the time slot where all calls have ended, the time The memory that controls the slots is sequentially switched from the system that holds the current connection pattern to the system that holds the new connection pattern. In this way, for all Mn time slots in one frame,
When the contents of the memory 99 are updated, the connection pattern change ends. If we assume that the amount of storage memory required in the method of the present invention is W2 bits, then
- As the scale of the distributor, 1=1″=8, n=20,
If m=24, from equations (1), (2), and (3), the scale of the holding memory according to the present invention is as follows in the conventional method:
Approximately 12% lower than when considering the characteristics at the time of connection switching
It can be seen that the size can be significantly reduced.

Moreover, the scale is about three times that of the case where the characteristics at the time of connection switching are not considered. However, considering that the holding memory is usually duplicated due to reliability conditions, and in the method of the present invention, one of the two memory systems can be used as a spare, the actual scale is approximately 1. You can think of it as a city double. As described in detail above, the distributor according to the present invention allows independent connection patterns to be established for each time slot without significantly increasing the amount of call holding memory from the minimum amount of memory required for semi-permanent switching. can be changed. The present invention is applicable not only to a distributor, but also generally to configuring a call retention memory of a semi-fixed switch in which a certain number of line groups are units.

[Brief explanation of the drawing]

Fig. 1 shows an example of the configuration of a call path switch, Fig. 2 shows an example of the configuration of a distributor, Fig. 3 shows a conventional example of a call holding memory in the distributor, Fig. 4 shows one frame on a highway, and Fig. 5 1 shows an embodiment of a call retention memory in a distributor according to the present invention. 70... Call holding memory, 80, 84, 85...
...Memory unit, 90,91...Holding memory, 92,93,100...Address counter, 94,95...Decoder, 96,97,98
...Switch, 99...J... Circulating memory, 7
1, 72, 73, 74, 75, 76, 77, 78, 79
...Control line, 200...Bus.

Claims (1)

[Claims] 1 has a communication path section consisting of a gate matrix and a communication holding memory that controls each gate of the matrix for each time slot within one frame, and has a communication path section on a plurality of time-division multiplexed highways. In the distributor, the holding memory is distributed over 1/m of one frame on the highway.
A plurality of memories provided corresponding to the input highway or output highway of the distributor, consisting of two systems: a first holding memory and a second holding memory, which circulate m times per frame with a capacity of (m is the number of lines in a distribution unit). a circular memory having a capacity equal to the number of communication paths in one frame on the highway and having a capacity that circulates once per frame and designating either the first holding memory or the second holding memory in each memory unit; and the circular memory. and a changeover switch that switches between the first holding memory and the second holding memory based on the designation of the above, and during normal operation, the connection pattern is stored in at least one of the first or second holding memory, and the circulating memory stores the connection pattern. Specify the first holding memory or the second holding memory that has the connection pattern, and when changing the connection pattern, store the new connection pattern in the holding memory that is not specified by the circulation memory, and press the changeover switch according to the specification of the circulation memory. A distributor characterized in that it selects a first or second holding memory.