JPH04134995A - Line assignment control system - Google Patents

Abstract

PURPOSE:To control a condition deciding a channel assignment on a line flexibly, and to make the difference of communication quality at every communication speed and between nodes small by using a line assignment control system. CONSTITUTION:A line controller C controls a communication channel in a line group by a free time slot number control means Ca at the time position of time slots TS1-TSN divided on a time base, and even when in lines L1-LM in this line group, the time slot number where there are more than 1 communication channel of unused communication channel on the same time slot exists more than a fixed number enable to be set optionally in whole, between the nodes, or at the communication speed, the communication line is assigned, and when the free time slot number is smaller than the fixed number, the assignment is not executed. Thus, it is possible to control the communication quality at every communication speed and between connecting devices flexibly by a simple control logic, and to eliminate the difference of the communication quality due to the communication speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is applied to a line allocation control method in a time division multiplex communication system.

In particular, the present invention provides for each communication speed in a time division multiplex communication system that provides multiple services with different communication speeds.
It is also used in line allocation control methods that control the communication quality between nodes.

[Conventional technology]

In recent years, the demand for communication has increased, requiring higher capacity communication lines. However, communication demands are based on time distribution, and line configurations based on the sum of the maximum communication volume for each terminal or node are not based on the network configuration. has the problem of excessive quality.

Therefore, for boat fishing, a bus-type configuration is adopted in which the line can be shared by each node, and the line form and the number of line-connecting devices are flexibly changed to satisfy a predetermined communication quality. This method is realized by an FDMA method in which lines are multiplexed on the frequency axis, or a TDMA method in which they are multiplexed on the time axis. Currently, a single carrier TDMA system is mainly used in which each node shares a single carrier having a channel divided into time slots on the time axis.

On the other hand, with the aim of making subscriber stations more economical, a multi-carrier TDMA system uses multiple lines (groups of lines) with a smaller capacity for each line, allowing each node's connection device to connect to any of the lines. Proposed.

In systems that provide multiple services with different communication speeds, there is a problem that line quality differs depending on the communication speed, so we developed a line that can eliminate the difference in line quality due to communication speed by changing the conditions that cause call loss. The allocation control method is important.

As a conventional line allocation control method, there is a channel number reservation method in which the difference between the maximum required number of channels and the number of channels of the target call is reserved in the line or in the line connection devices of all nodes.

[Problem to be solved by the invention]

In the single-carry TTDMA system described above, if a channel on a carrier is in use, the time slot position corresponding to that channel becomes unavailable for use by all nodes other than the node using the channel. It is only necessary to manage the number of channels, and the conventional channel number reservation method can be implemented with very simple logic.

However, in the multicarrier TDMA system, multiple communication channels exist in the same time slot. Therefore,
In the conventional channel number reservation method, single carrier TD
Since the MA method is targeted, even if channel allocation is possible if there are available free channels, in the multicarrier TDMA method, if there are not the required number of free channels with different time slots, the allocation will not be possible. It becomes impossible.

An example of this is shown in FIGS. 3(a), (b) and (C).

In FIGS. 3(a), (b) and (C), Nl and N2 are nodes, N1T and N2. is the transmission section of the line connection device, N1. and N21 is its receiving part, L is a line group including individual lines L1 to L6, and Ts 1
~Ts 8 is a time slot, the shaded part represents a channel in use, and ○ represents an empty channel.

Assuming that only one call exists at a time at the originating and terminating node, all eight time slots are vacant when a call occurs. As shown in Figure 3(b), when there are 12 free channels in the line group, there are only 4 free channels with different time slots, so it is possible to allocate a 4-channel call. , 6-channel calls have the disadvantage that allocation is impossible due to the lack of free time slots in the line group.

An object of the present invention is to eliminate the above-mentioned drawbacks and improve communication speed in order to efficiently utilize lines in a time division multiplex communication system that provides a plurality of services with different communication speeds using a multicarrier TDMA communication method. An object of the present invention is to provide a line allocation control method for allocating communication channels so as not to cause a difference in communication quality.

[Means to solve the problem]

The present invention provides a line group including a plurality of lines configured of time-divided communication channels, a plurality of nodes having line connecting devices for connecting connected terminal devices to the line group, and In a line allocation control method in a time division multiplex communication system that includes a line control device that manages communication status, the line control device assigns call-by-call control to multiple calls with different communication speeds based on requests from each node. and a number control means for controlling the number of empty time slots that allocates a communication channel when there is a predetermined number or more of empty time slots to which no communication channel is allocated on the same time slot. It is characterized by containing.

Further, in the present invention, the certain number of empty time slots is
It is preferable to individually set each communication speed for a plurality of communication speeds.

Further, in the present invention, the certain number of empty time slots is
Preferably, it is set for each individual node.

[Effect]

The line control device manages the communication channels within the line group by the time positions of the time slots separated on the time axis by means of controlling the number of free time slots, and allows multiple lines within the line group to use the same time slot. A communication channel is allocated only when the number of free time slots in which there is one or more unused communication channels is greater than a certain number that can be set arbitrarily for the whole, for each node, or for each communication speed. No allocation is made if the number of time slots is less than a certain number.

Therefore, communication quality can be flexibly controlled for each communication speed and for each connected device using simple control logic, and differences in communication quality depending on communication speed can be eliminated.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.
1 shows a time division multiplex communication system using a multicarrier TDMA communication method.

In this embodiment, a line composed of time-divided communication channels is a line group in which a plurality of lines LI-Lx exist, and a line connecting a connected terminal device T Il-1-Tn- to the line group. In a line allocation control method in a time division multiplex communication system including a plurality of nodes N1 to N each having a connection device N I a ” N h a and a line control device C that manages the communication state of a group of lines, A feature of the present invention is that the line control device C is configured to allocate channels for each call based on requests from each node N1 to N for multiple calls having different communication speeds, and allocate channels at the same time. It includes an empty time slot number control means C6 that allocates a communication channel when the number of empty time slots to which no communication channel is allocated is equal to or greater than a predetermined number.

Then, a certain number of empty time slots is set individually for each communication speed for a plurality of communication speeds, or a certain number of empty time slots is set for each individual node.

Next, regarding the operation of this embodiment, FIGS. 2(a) to (6)
This will be explained with reference to the line allocation explanatory diagram shown in FIG. The figure shows a case where the line group includes individual lines L1 to L6 and the time slots are 10 time slots Ts 1 to Ts 10. In the figure, the shaded parts indicate the channels in use. , ○ represents an empty channel, and the number surrounded by ○ in the lower row represents the number of empty channels existing in the relevant time slot.

Line control device N1. of nodes N1 to N1. The transmitting/receiving unit (Nl□, N0R) in ~N□ has different lines for each node at time slots T, 1 to T, N, -L,
It is possible to connect to the time slots Tsl to TsN of .

When a call originates from terminal T1-1, line group connecting device Nl
Send information on the number of required channels from a to the line control device C,
The line control device C counts the time slots including free channels on the line and allocates the line, and the free time slot number control means C6 connects the line group connection device Nla of the originating side node N1 to the terminating side node N2 through the control line. Set up a communication route to the line connection device N2m, and connect the terminal device T.
1-1 and terminal device L-+ are connected.

Line allocation control in this case is shown in Figure 2 (a) to (6).
Explain using.

There may be 0 to 6 free channels in each of the time slots TS1 to TslO of the line group.

The line control device C counts the number of time slots with free channels on the line using the free time slot number control means Ca, regardless of the number of free channels existing in each time slot. In FIG. 2(a), empty channels exist in nine time slots except time slot Ts 9, where all channels are in use. If the number of empty time slots does not reach a certain number determined by the communication speed or between nodes, no line is allocated.

Between connected devices where this constant number is set to a small value, the conditions for call loss are less severe than between nodes where this constant number is set to a large number, and communication quality improves.

Here, considering the situation where calls requiring 2 channels and calls requiring 6 channels coexist in both the upstream and downstream calls at the same speed, 2 channel calls leave 4 time slots, which is the difference from 6 channel calls. Allocate channels to

First, when a 6-channel call occurs, line allocation management searches for an empty channel from the time slot position following the end of the previous search, and after confirming that there are 6 or more time slots with empty channels, performs a search as shown in Figure 2. As shown in (b) with A added, channels are allocated so that many time slots with empty channels remain.

Similarly, for the next 6-channel call, channels are allocated as shown by adding B in FIG. 2(C).

When two channels are allocated to the next two-channel call, the number of time slots with empty channels becomes three, as shown in FIG. 2(d), so the call is considered to be a lost call.

In other words, for a call that requires two channels that occurs in a certain state, is it possible to leave an empty channel in the time slot on the line that is the difference from the call that requires the most channels? The allocation is performed after determining whether there are four.

As described above, if whether or not to allocate a channel on a line is determined under the same conditions regardless of the communication speed of a call that occurs in this state, differences in communication quality depending on the communication speed can be made less likely to occur.

In addition, by arbitrarily setting this constant number for each node or for each communication speed, when a group of lines includes services with different communication speeds such as upper and lower speed communication or broadcast communication, it is possible to It is possible to change the service or the communication quality between specific nodes.

〔Effect of the invention〕

As explained above, by using the line allocation control method according to the present invention, it is possible to flexibly control the conditions for determining whether or not to allocate channels on the line, thereby reducing the difference in communication quality between each communication speed and between nodes. It is also possible to flexibly control specific services and communication quality between connected devices.

Furthermore, since the present invention only needs to manage the number of time slots in which free channels exist on the line, the effect on control processing is small and can be realized using a simple control theory.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention. FIGS. 2(a) to 2(6) are explanatory diagrams showing the line allocation method. FIGS. 3(a) to 3(C) are explanatory diagrams showing a conventional line allocation method. C... Line control device, C6... Vacant time slot number control means, L... Line group, L1 to L! ...line,
N1-N,... Node, N16-N,,2... Line connection device, NIR-NhiI... Receiving unit, N17,
N2. ...Transmission unit, T, -1 to Th-+a...Terminal, T,1-T, N...Time slot. Patent applicant: Nippon Telegraph and Telephone Corporation. Agent Patent Attorney Nao Takashi Ide (2G) T! 1 (20) T! 1 ■Φ■■■■0■ (a) ■ ■■■ ■■■■ (b) ■ (20) Tsl (20) Tsl ■ ■■■ ■ (C) ■ ■■■ (d) ■ Example (Line allocation explanatory diagram) Figure 2

Claims (1)

[Scope of Claims] 1. A line group including a plurality of lines constituted by time-divided communication channels, and a plurality of nodes having line connection devices that connect connected terminal devices to the line group; In a line allocation control method in a time division multiplex communication system comprising a line control device that manages communication status of the line group, the line control device responds to requests from each node for multiple calls with different communication speeds. An empty time slot to which a communication channel is allocated when there is a predetermined number or more of empty time slots in which no communication channel is allocated on the same time slot. A line allocation control method characterized by including a number control means. 2. The line allocation control method according to claim 1, wherein the fixed number of vacant time slots is individually set for each communication speed for a plurality of communication speeds. 3. The line allocation control system according to claim 1, wherein the fixed number of free time slots is set for each individual node.