JPS6189751A - Loop network transmission control system - Google Patents

Abstract

PURPOSE:To prevent the increase of the delay time of a packet switching signal and that of the connection delay time of a line switching signal even if the line switching signal is in the overload state, by setting the first use slot number limit standard value and the second use slot number limit standard value which is not larger than the first standard value. CONSTITUTION:A total number 516 of slots used for line switching is inputted to a comparing circuit 55 from an adder 52. The comparing circuit 55 sends a set signal 519 to an FF56 when the total number 516 is larger than the first use slot number limit standard value N1 stored in a register circuit 53, and the circuit 55 sends a reset signal 520 to the FF56 when said number 516 isd smaller than the second use slot number limit standard value N2, and the FF56 isheld turned on or off. Its state signal 521 becomes the input signal to an FF57, and in the next frame, it is turned on when the total number 516 is larger than the standard value N1 and is turned off when the total number 516 is smaller than the standard value N2 and is held in the state for the preceding frame when the total number 516 is between standard values N1 and N2, and the result is sent to a control circuit 33 as a control signal 522 for connection of a new call of the line switching signal, and the control state is set when the signal 522 is turned on, and the non-control state is set when it is turned off.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is directed to the use of loops and networks in a switch configuration that integrally exchanges circuit switching signals for real-time services and waiting service switching signals. This paper relates to a transmission control system with a configuration that has been used.

(Prior Art) In recent years, various systems for local area networks or exchanges that integrally transmit and exchange circuit-switched signals and packet-switched signals have been proposed and are attracting attention. As a switch configuration method, a method is known in which multiple nodes called switch modules are connected by a loop network (IEICE Technical Report 5E83-
148). In this system, switching and operation are realized by mutually transmitting and receiving circuit switching signals and notebook switching signals between nodes via a loop network. The method for accessing the loop, ↑, and twerk has a plurality of slots s1. on the loop as shown in FIG. s2...,
A frame made of Sn is provided. Each slot is
The slot display part SI, the overhead parts SA and DA such as the originating and receiving node addresses, and the information part, and the information part contains a circuit switching signal, a packet switching signal, or an inter-node exchange of both of the above signals for setting up a call. The control signal is divided and stored according to its required transmission rate. The slot display section SI identifies slot usage status of vacant slots and circuit exchange signals, mother packet exchange signals, and inter-node exchange control signals. Circuit-switched signals or network-switched signals are subdivided into slot sizes, hunted for the required number of empty slots, and transmitted on a loop.

However, in this case, in order to satisfy the immediacy of the circuit-switched signal, each node sends the signal to the loop with first priority. Furthermore, if it is desired to increase the number of slots required for transmission as the number of calls increases, a hunt for empty slots is performed. Once the required number of hunts are successful, the required number of slots can be automatically secured every period based on the following principle. In other words, the vacant slots to be hunted include those that become vacant due to reception at the own node, and if the circuit-switched signal is bidirectional symmetric communication, the number of slots required for transmitting the signal is at least This is because the double cycle is always secured by releasing the reception slot from the partner node regarding the reverse call. On the other hand, the node exchange signal and the inter-node exchange control signal, which are allowed to wait, can be performed while waiting for a vacant space on the second priority system.

FIG. 4 shows this basic configuration, in which nodes 4P1. ≠2 3゜φ4
．． ÷5. An example in which +6 is connected is shown. Each node is
In response to the circuit switched signal, the slot display section, the departure/arrival node,
- A multiplexing circuit 36 that adds an address, multiplexes it onto a slot in a frame, and sends the multiplexed signal to the insertion circuit 32 creates a serial queue for the packet switching signal that is a waiting call, and displays the slot. □Insert circuit 3 as necessary.
2, an insertion circuit 32 that inserts a packet exchanged signal from its own node into an empty slot in accordance with instructions from the control circuit 33 into the multiplexed line exchanged signal, and an insertion circuit 32 that sends a signal to its own node from the loop. Detects the destination slot signal and sends it to the branch circuit 34, receives the signal from the insertion circuit '32 □Sends the signal addressed to its own node for the empty slot to the loop, and further sends the empty slot position information to the control circuit 33 A circuit 37 receives the signal addressed to its own node from the loop interface 31 and reads the slot display section SI to separate the circuit switching signal, packet switching signal, and inter-node switching control signal. A reception buffer, a branch circuit 34 that sends data to the control circuit 33, a separation circuit 37 that functions in the opposite direction to the multiplexing circuit 36, and a reception buffer 38 that functions in the opposite direction to the transmission buffer 35. The slot position information to be used is sent to the multiplexing circuit 36 and the separation circuit 37, and the slot position information that is not used for communication addressed to the own node or between other nodes is sent to the insertion circuit 32, and exchange between nodes is performed. It is comprised of a control circuit that receives a control signal from the branch circuit, sends it to the insertion circuit 32, and further controls call setting.

FIG. 5 is a diagram for explaining an example of the operation of the communication method based on the present loop network access method. In this example, the received signal from the loop and the transmitted signal to the loop are shown for nodes #1 to #3, respectively. For example, node #1 receives a circuit-switched signal addressed to its own node from node #2 in slot S1, so it enters that slot and sends the same signal addressed to node #2 from its own node in the opposite direction to node #1. The same slot was used to send the packet, and since slot S2 was empty, the packet exchange signal was sent to node #3, and since the own node was not involved in slot S3, it was passed through as is, and slot S4 was sent to node #5. A packet exchange signal arrived from node #4, so it was taken in and the same signal addressed to node #6 was sent instead.In slot S5, a packet exchange signal from node #4 was received, but there was no new signal to send. Therefore, the slot is left unused and the operation is repeated. However, in the above operation description, inter-node exchange control signals have been omitted for simplicity.

As can be seen from the above explanation, the integrated switching system for circuit-switched signals and packet-switched signals using a loop network has a simple configuration, is suitable for autonomous control and distributed control, and always maximizes the available slots for circuit-switched signals. For loop use
It is possible to improve the efficiency of the network and at the same time configure a comprehensive communication network with high flexibility and variability.If realized with a multiple loop configuration, it will improve reliability and increase flexibility for increasing switching capacity. It has many features such as:

(Problem to be Solved by the Invention) However, the above method has the disadvantage that, due to its operating principle, slots cannot be secured for packet switching signals and inter-node switching control signals when circuit switching signal calls become overloaded. As a result, the delay time of packet-switched signals suddenly increases, deteriorating service quality, and even for circuit-switched signals, the delay time of new call connection increases due to the increased delay of inter-node switching control signals. be.

The present invention provides an integrated switch configuration for circuit-switched signals and packet-switched signals using a loop network, which reduces the delay time of packet-switched signals and the connection delay time of circuit-switched signals even when the circuit-switched signals are overloaded. The purpose of this paper is to provide a transmission control method for a loop network that does not cause network expansion.

(Means for Solving the Problems) The present invention includes a communication loop and a plurality of communication nodes connected via the communication loop, and a frame consisting of a plurality of slots on the time axis of the communication loop. provided, in a loop network that integrally transmits circuit-switched signals and four-kett-switched signals using the slots, a first usage slot number restriction standard value for circuit-switched signals, and whether the number of used slots is smaller than the standard value; or a second used slot number limit reference value that is equal to the number of used slots, and in each node, the total number of used slots used for circuit switching signals that pass over the own node and are sent out from the own node within one frame is equal to the first number of used slots. When the number of used slots is greater than the limit reference value, it becomes a restricted state that prohibits the setting of new calls for circuit-switched signals from the next frame onward, and once the restricted state is reached, the total number of slots used for the circuit-switched signals is This is a loop network transmission control system characterized in that only when the number of used slots becomes smaller than the second reference value for limiting the number of used slots, the system returns to an unregulated state in which new call settings are allowed from the next frame onward.

(Example) Next, an example of the present invention will be explained using the drawings. Figure 1 is a system configuration diagram showing an example of the present invention, and Figure 2 is a diagram for explaining the operation. It is a diagram.

The system configuration at each node according to the present invention is the loop interface 31, control circuit 33, etc. described in the conventional example.
In addition to the branch circuit 34, it includes a counter circuit 51, an adder 5λ register circuit 53, a register circuit 54 comparison circuit 55, a set/reset flip-flop 56, and a D flip-flop 5. However, in addition to this, in order to communicate circuit-switched signals and packet-switched signals, an insertion circuit 32I% transmission buffer 35. Although the multiplexing circuit 3 requires a demultiplexing circuit 37 and a receiving buffer 38, they are omitted here for the sake of brevity. The loop interface 31 newly creates a frame start pulse 512 from the signal on the loop 30 and supplies it to the counter circuit 51 and the D flip-flop 57. The control circuit 33 newly supplies the use slot number information 515 of the own node circuit exchange signal to the adder 52. The branch circuit 34 newly supplies the counter circuit 51 with a detection signal 513 of a line exchanged signal between other nodes that passes over its own node.

The counter circuit 51 is activated by the frame start pulse 512.
After its contents are cleared, the number of slots used for circuit exchange signals between other nodes in the frame is counted, and the count information 514
and information on the number of slots used for circuit exchange originating from the own node 51
5 is added by the adder 52, and the total number 516 of the number of slots used for line switching in the loop on the own node is inputted to the comparison circuit 55. The comparison circuit 55 calculates the total number 5.
16 is compared with the first used slot number limit reference value stored in the register circuit 53 and the second used slot number limit reference value stored in the register circuit 54, and
When the reference value of is also large, the set signal 519 is
When the value is smaller than the second reference value, the reset signal 5 is output.
20' is sent to the set/reset flip-flop 56, in which the on and off states are maintained, respectively. The on or off state signal 521 is the D flip-flop 5.70 input signal,
The total number of used slots, which is the number of slots used for circuit switching signals in the loop on the own node, in the next frame described here, by being turned on and off at the rising edge of the frame start signal 512. is larger than the first reference value, it is in the on state; when it is smaller than the second reference value, it is in the off state; for values in between, the state of the previous frame is held, and the result is used as a new circuit-switched signal. It is sent to the control circuit 33 as a restriction signal 522 for the connection of a call, and when the signal 522 is on, it is in a restricted state, and when it is off, it is in an unrestricted state.

FIG. 2 is a diagram showing an example of the operation of the present invention. The total number of slots in one frame is N1, the first standard value is N2, and the second standard value is N2.
An example is shown in which the standard value of is set to N1. Areas where the total number of slots used for circuit-switched signals in the loop on each node is small (
The number of calls increases gradually from N1 (below N1), and when it exceeds N2, the connection of circuit-switched signal calls is restricted, and new calls are lost. Even if it increases or decreases further, the restricted state will not be canceled unless it becomes N1 or less.

(Effects of the Invention) As can be seen from the above explanation, according to this method, the total number of slots used for circuit switching signals in the loop on each node is kept to N2 at most, so that access can be achieved from all nodes. (N-N2) slots are reserved for packet exchange signals, and there are no empty slots even when there is an overload of recollection exchange signals, and this is for packet exchange signals and inter-node exchange control signals. A certain level of delay time, that is, service quality can be guaranteed.

In addition, two overload detection standard values are prepared instead of a single one.
By providing so-called hysteresis characteristics, the delay time of packet switching signals and inter-node switching control signals can be gradually reduced until the overload condition of circuit switching signals subsides. It will be done.

[Brief explanation of drawings]

Figure 1 is a block diagram of the first embodiment according to the present invention, the second figure is an explanatory diagram of the operation of the first embodiment, and the third figure is a diagram of the loop of the conventional line/packet integrated switching system. FIG. 4 is a system configuration diagram of a conventional line/packet integrated switching system, and FIG. 1 is an explanatory diagram of the operation of the conventional system shown in FIG. 4. S 1”+8”2 m 83 ss4; s 5; 8
'6 s S 7, S-8, N9 pSlo"F S
N I L SN2 ss'N・:・xt1t number,
SI...Slot display &, 'I)A...Call nonid...
Address, SA... Originating node address, C8...
・Paint exchange signal, PC...Packet exchange signal, N1・
...Second setting standard value, N2...First setting standard value,
N...Total number of slots S■Slot display section DA: View node address section SA: Zumura node address section

Claims (1)

[Claims] (1) A communication loop and a plurality of communication nodes connected via the communication loop are provided, and a frame consisting of a plurality of slots is provided on the time axis of the communication loop, and the slots are used to exchange circuit-switched signals. In a loop network that integrally transmits packet-switched signals, a first usage slot number limitation criterion value and a second usage slot number limitation criterion value that is smaller than or equal to the criterion value are set for the circuit switching signal. and in each node, the total number of used slots used for circuit switching signals that pass over and are transmitted from the own node within one frame is determined by the first
When the number of used slots is greater than the limit reference value, it becomes a restricted state that prohibits the setting of new calls for circuit-switched signals from the next frame onward, and once the restricted state is reached, the total number of slots used for the circuit-switched signals is A loop network transmission control system characterized in that only when the number of used slots becomes smaller than the second reference value for limiting the number of used slots, the system returns to an unregulated state in which new call settings are allowed from the next frame onwards.