JPS6031340A - Time division line channel selecting system - Google Patents

Abstract

PURPOSE:To decrease the call loss by combining plural idle channels among channels at each speed class arranged periodically on a multiplex line to attain band assignment on a transmission line to a call having an optional band. CONSTITUTION:A speed combination pattern table representing the speed combination pattern to realize an optional speed class through the combination of plural basic speed classes and a subscriber channel utilization map are provided, a channel not in use is detected from the subscriber channel utilizing map to a call comprising an optional speed class, and the said channel not in use is combined according to the speed combining pattern to execute channel assignment to the call. Cz (z=1, 4, 8, 16) in the combination pattern table by speed indicates a speed class requiring a band being Z-times the band of a basic call (Z=1). In the subscriber channel utilizing map, a time slot number in one sub-frame is plotted in the ordinate axis (x) and the idle/ready state of the operating channel between sub-frames, speed class and an idle channel number are displayed in the abscissa (y).

Description

[Detailed Description of the Invention] [Field to which the invention pertains] The present invention provides a time-division multiplex line that effectively utilizes the vacant time slots 1 to 2 of the time-division multiplex line to reduce call loss on the time-division multiplex line. Concerning channel selection method.

[Prior art]

Traditionally, to realize data exchange, time division multiplexing
The subscriber data multiplexed on JL 2 is a mixture of low-speed data and high-speed data, and the time slots 1 to 1 assigned to these JLs are multiplexed on time division multiplex line 7 for the purpose of facilitating call processing. It was based on the premise of a periodic arrangement that is allocated periodically.

FIG. 1 is an example of a multiplexing configuration on a time division multiplex line. In this example, one data frame 11 is composed of 16 subframes 11 #1 to #16, and each subframe 1
11 to #16 indicate a case where 12 signals are multiplexed. Therefore, in this multiplexing configuration, in the case of only basic calls (calls that are multiplexed and transmitted by the lowest speed bare frame 1-), multiplex transmission of subscriber data of +92N, 6X12=192) is possible. On the other hand, in the case of a II-fold call that requires 1 times the bandwidth of the basic call, for example, assuming that the third time slot 1 to position in subframe #l is used for the 16-fold call, , 3rd g! in each subframe from tt2 to #1G! The i-th timeslot 1-position will be used periodically for 16x calls. Therefore, if all the channels allocated for 16x calls in each speed group are used, there are still time slots allocated for 2x calls, 4x calls, etc. in other speed groups. Even if the bandwidth necessary for a 16x call can be secured by combining these methods, there is a drawback that a 16x call that newly generates a communication request cannot be multiplexed on the transmission path.

[Purpose of the invention]

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to reduce the bandwidth of the network by combining a plurality of empty channels among the channels for each speed class arranged periodically in multiple lines. The object of the present invention is to make it possible to allocate an IF area on a transmission path to calls that have calls, and to reduce call loss.

[Summary of the invention]

In order to achieve the above object, the present invention provides a method for time-divisionally transmitting data from a data terminal by assembling frames using channels arranged periodically on a time-division multiplex line corresponding to a plurality of basic speed classes. a speed combination pattern table showing a speed combination pattern for realizing an arbitrary speed class by combining the plurality of basic speed classes; and a subscriber channel usage map showing channel availability information for each of the basic speed classes. and detecting unused channels from the subscriber channel usage map for calls of arbitrary speed classes, and performing channel assignment for the calls by combining the unused channels according to the speed combination pattern. [Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a diagram showing a speed-based combination pattern table for each speed class that is necessary to implement the present invention.

Here, Cz (z=1.4.8-16) is the basic call (Z
For example, the speed class for a 16x call requires a bandwidth 16 times that of a basic call (C88). Therefore, for the speed class C□6 of a 16x call, the combination of various speed classes to secure the required bandwidth is 1 as shown in Figure 2.
0 types are possible. For example, speed class C for a 16x call
16 is a combination of one speed class C for 8x calls and two speed classes C for 4x calls (for pattern type PT3)
or a combination of three speed classes C4 for quadruple calls and four speed classes C4 for basic calls (pattern type PT
7), it is possible to secure the bandwidth necessary for the 16x call speed class CIF, and it can also be achieved by other combinations (pattern types PT1.2.4.5.6, 8.9, ]C0). You can also use other speed classes Ch.
, C1, Cr can be secured in the same manner as necessary for the speed class.

Generally, this method can be easily applied by determining the speed type of the basic speed class defined by the multiplex transmission path-L.

In Figure 3, the vertical axis (x) shows the time slot number within one subframe, and the horizontal axis (y) shows the busy state of the used channels between each subframe, speed class, and number of free channels. This is a subscriber channel usage map displaying .

In FIG. 3, when X=1, the speed class is basic speed class C3, and 1 in the subframe of tt9,112.
This shows that there are 2 free channels with 1 to 2 dowels each. When x = 2, the speed class is C6 for quadruple calls, and subframes 34.
38, #12, #■G, time slot 1- at the second slot is empty time slot 1-, and 4 time slots 1 are empty, and there is 1 empty channel for quadruple call. Indicates that it exists. In addition, in the figure, the meaning of "repeat" is that speed class C1 requires a bandwidth four times that of speed class C1 of the basic call, and in order to efficiently obtain this four times the bandwidth, periodic arrangement is necessary. This is because it is necessary to use the four time points 1 to 1 that have been set. That is, subframe #1. #5, #9.
One channel for the quadruple call is formed by the second time slot 1- of #I3 and #b. Similarly,
The second time slot of each subframe #2, tt6.410, #14 forms the second channel for quadruple calls, and the second time slot of each subframe #3, #7, #11, #15
The third channel for the quadruple call is formed by the second time slot 1~.

When x=3, the call speed class is 166 times C16,
Since a bandwidth 16 times that of a basic call is required, the third time slot 1- of all subframes #1 to #1G is used, and the number of vacant channels is zero.

Hereinafter, the status of empty channels within one data frame 11 can be explained in the same manner.

The vertical axis position ff1x (time slot numbers 1 to 12 within one subframe) and the horizontal axis position y (subframe numbers #1 to #16) are given, and the speed class CZ
(Z=1.4.8.16 in the case of Figure 3) is determined, l
The serial number No. (1 to ■92) of allocated time slots within a data frame is given by the following equation.

No= 1.2
)1 In this embodiment, the number of subframes is 16 and the multiplicity within one subframe is 12, but generally, the number of subframes is P and the multiplicity within one subframe is 12. is 9, the allocated time slot consecutive number No.
teeth.

No=qX (P/Z
2) However, M=O, l, 2,..., (Z-1,)2
is determined by the divisor of P.

With reference to FIG. 3, a method of allocating an empty time slot 1- when a new 166 times call communication request occurs will be explained.

In the case of a 166-fold call, as shown in Figure 2, the pattern types that can be combined are PTI, PT2, PT3, .
・, PTiO corresponds to this. Here, the pattern PTI is
This is a case where a channel for a 16x call can be secured at once within a data frame of the same speed group, and in the subscriber channel usage map shown in Figure 3, a channel for a 16x call (C+6
(corresponding to the speed class of ) are all in use, so the pattern PTI shown in FIG. 2 cannot be used. Next, pattern PT2 shown in Fig. 2 is a case where two channels for 8x calls can be secured at once, and in Fig. 3, the channels for 8x calls (corresponding to the speed class of co) are shown. Since only channel ■ is available, this pattern is also unusable.

Next, pattern PT3 is a case where one channel for an 8x call and two channels for a 4x call can be secured, and by combining the empty channels indicated by 0, which are indicated by squares in Figure 3, It can be seen that it is possible to allocate a speed band for a 16x call.

The assignment results are shown in FIG. 8x call speed class C
8, it is necessary to use time slots in every other subframe, and according to the subscriber channel utilization map of FIG. 3, even numbered subframes #2, #4, $6. #
The fourth tie 11 slots of 8, #10, and #12tt-14, and 316 are vacant, so they are used.

Also, speed class C4 for quadruple calls requires the use of time slots in every third subframe, and according to the subscriber channel usage map in FIG.
, #8, #12, and #16, the second and eighth time slots are vacant and are utilized.

Note that when applying the same pattern PT3, a speed class C4 with x=12 may be used in addition to the example shown in FIG.

Below, when patterns P74 to PTIO are examined in the same way, it is found that in the example subscriber channel usage map shown in FIG. 3, patterns PT4 to PT8 can also be used for 16x calls in addition to pattern PT3. Recognize.

That is, as a result of combining channels available on the subscriber channel usage map, if there is one that matches usage patterns of various speed classes, it is possible to allocate channels by just one. Therefore, for a newly requested 16x call, one of these available patterns may be selected, and the resulting time slot number may be calculated and assigned.

Note that after time slot allocation, it is necessary to update the subscriber table. This update is performed by changing the empty/busy indication of the assigned channel from 0 to 1, and further subtracting the number of free channels at the address.

It is also necessary to update this subscriber table for terminals for which two communications have been completed. This update changes the empty indication of the allocated channel at the address from 1 to O,
Increase the number of free channels by the allocated amount.

Below, I explained the communication request for 16x calls, but the fifth
According to the flowchart i in the figure, empty time spot 1 for communication requests by basic call, 4x call, 8x call, and 16x call
I will explain how to divide (=I).

If there is a communication request from a terminal, it is determined whether or not to search for free time slot 1 (501), if not, it is determined whether the subscriber is disconnected or not (502), and if no, it is returned from the terminal as it is. Waits for a communication request, and if the subscriber is disconnected, changes the empty indication of the channel allocated to the subscriber from the subscriber channel usage map from 1 to 0, and increases the number of empty channels by the allocated amount. Update 50
3) Prepare for communication requests from terminals.

If searching for an empty time slot, determine how many times the requested speed class is for the call (50/I); if speed class C4 is for a basic call, search the subscriber table for basic calls in the subscriber channel usage map. 505), pattern type PT17
506), and if it is possible to secure a free channel, calculate the tie 11 slot 1 consecutive number for the basic call. At the same time, the subscriber channel usage map is updated (524).

If a free channel cannot be secured, multiplexing is impossible, so a busy notification is sent (508).

If the requested speed is 4x call, 8x call, or 16x call, the initial value of pattern number n of pattern type PTn corresponding to each requested speed is set to 15.11, l,
Index the speed combination pattern table for each requested speed 509゜510.511), judge whether or not an empty channel that matches each pattern type PTD can be secured 512.513.5z), and if it can be secured, each request Calculate the serial number of vacant time slots for speed (521.522.523), assign the calculated vacant time slots to the terminal that has requested communication, and update the subscriber channel usage map based on it (521.522.523).
4).

If a free channel that matches the pattern type PTn corresponding to the requested speed cannot be secured, each pattern number continues to be incremented by 1 until a pattern type P T n that can secure a free channel is found (515.5] 6.517.518
．． 519.520). Pattern type PT that corresponds to the required speed
If it is not possible to secure free channels for all of n,
A busy notification is sent (508).

Although empty time slots are allocated to a call with one communication request through such a processing flow, this algorithm can be easily programmed using an existing processor.

Note that in the above embodiment, the speed series on the multiplex transmission path is the basic call,
Although this was the case for 4x calls, 8x calls, and 16x calls, this rate series can be easily expanded. In addition, by combining channels with these speed types on a multiplex transmission path, 1, for example, a 5x call (C, -1-
C,), 6-fold call (C, +C, 10C,), 7-fold call (C, +
C, +C+ 10C,), 9 times call (c, +c, 10C,)
, c, +C1,...), 32 times call (C,, +C□FI
If a band such as CII+C, +C, . . . ) is required, it is also possible to allocate the necessary band to the requested channel as appropriate.

〔Effect of the invention〕

As explained above, according to the present invention, by combining a plurality of empty channels among the channels for each speed class arranged periodically on a multiplex line, a call with an arbitrary band can be transmitted on a transmission path. This makes it possible to allocate bandwidth, reduce call loss, and improve transmission efficiency.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a multiplexing configuration on a conventional time division multiplex line, FIG. 2 is a diagram showing a speed combination pattern table for each speed class according to an embodiment of the present invention, and FIG. is a subscriber channel utilization map according to an embodiment of the present invention, FIG. 4 is a diagram illustrating time slot I-allocation on multiple lines according to an embodiment of the present invention, and FIG. Time slot 1~allocation is a flowchart for explaining the process. C3: Basic call speed class, C4: 4x call speed class, C8: 8x call speed class, C1,: 166x call speed class, P T n (n = ], -] 7)
: Speed pattern combination type.

Claims (1)

[Claims] (1) In a method in which data from a data terminal is assembled into frames and time-divisionally transmitted using channels arranged periodically on a time-division multiplex line corresponding to a plurality of basic speed classes, the plurality of basic speed classes A speed combination pattern table showing a speed combination pattern for realizing an arbitrary speed class by combining the basic speed classes, and a subscriber channel usage map showing channel air cooling information for each basic speed class are provided. A time division line channel characterized in that channel allocation for the call is performed by detecting unused channels from the subscriber channel utilization map and combining the unused channels according to the speed combination pattern. Selection method.