JPH02252337A - Loop network - Google Patents

Abstract

PURPOSE:To attain the transmission between terminal equipments belonging to a low speed network without a gate way or a PBX by assigning plural low speed network assignment areas so that parts of them are overlapped with each other. CONSTITUTION:In the case of building up a loop network 15 by connecting two low speed networks A, B to a high speed network, a high speed network node 12 and nodes 30a, 30b of the low speed networks A, B are provided to the network 15. In this case, a low speed network A use area 23 and B use area 24 are provided to a transmission frame 20 of the high speed network and an area 25 is assigned so that parts of them are overlapped with each other. Then a transmission frame of the two low speed networks A, B is given to the areas 23, 24, the frame is actually sent onto the loop by the high speed network and the communication between the terminal equipments of the networks A, B is implemented by using the area 25. Thus, the transmission between terminal equipments belonging to the low speed network is attained without a gateway or a PBX.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a loop network that combines two types of loop networks with different transmission speeds.

[Background Art] In recent years, with the development of the information society, more comprehensive network systems are often formed by connecting new types of networks.

For example, FIG. 5 shows a case where one loop network 14 is constructed by combining two loop networks 10.11. Here, both the loop network 1o and the loop network 11 have a configuration in which frames of a certain length circulate on loops, and the loop network 1o and the loop network 11
The network has a higher transmission speed than 1. Hereinafter, the loop network 1o will be described as a "high-speed network" and the loop network 11 as a "low-speed network."

Note that 12 is a high-speed network node, and 13 is a low-speed network node.

FIG. 6 shows the structure of a transmission frame 20 of the high-speed network 10. 22 is a frame header of the high-speed network 11. In order to incorporate the low-speed network into itself, the high-speed network 10 specifically allocates a portion 21 of the transmission frame 20 for the low-speed network.

Then, the low-speed network 11 places its own transmission frame on this area 21 and transmits it on the loop, leaving the actual transmission to the high-speed network 10.

By adopting such a network configuration, it becomes possible to accommodate terminals belonging to the low-speed network 11 in the high-speed network 10.

Here, consider a case where the number of terminals connected to the low-speed network increases in the entire system and cannot be accommodated by one low-speed network 11. In this case, two low-speed networks A and B are connected to the high-speed network 10 to construct one loop network 15 as shown in FIG. 3.

At this time, regarding the area allocation within the frame 20 of the high-speed network, as shown in FIG. 4, an area for the low-speed network A and an area for the low-speed network B are provided separately.

[Problem to be solved by the invention] However, in this case, the low-speed network A and the low-speed network B are completely different networks, so there is no communication between the terminal connected to the low-speed network A and the terminal connected to the low-speed network B. Therefore, when building a system, there is a restriction that the communicating terminals must belong to the same network.
It becomes less flexible. Furthermore, future expansion is not easy.

Also, similar to the conventional connection between LANs, if a gateway or PBX is placed outside, transmission between terminals on different low-speed networks A and B is possible through it, but even in this case, a separate gateway or PBX must be installed. Not necessarily,
There is a problem with the division height.

SUMMARY OF THE INVENTION An object of the present invention is to provide a loop network that eliminates the drawbacks of the prior art described above and allows transmission between terminals belonging to a low-speed network without a gateway or PBX.

[Means for Solving the Problems] The loop network of the present invention is made up of a combination of two types of loop networks with different transmission speeds in which transmission frames of a fixed length circulate on the loop, and the loop network with the higher transmission speed is A first loop network uniquely allocates a part of its own transmission frame for transmission by a second loop network having a lower transmission rate, and the second loop network assigns its own transmission frame to the allocated area. In a loop network in which one actual transmission is carried out on a loop by a first loop network, when there are a plurality of second loop networks connected to the first loop network, the first loop network is connected to a plurality of second loop networks. The two loop network allocation areas are allocated so that a portion of each area becomes a Japanese-style room.

[Operation] When a first loop network with a high transmission speed (high-speed network) allocates an area within the high-speed network frame to a plurality of second loop networks (low-speed networks) with a lower transmission speed, Allocate the allocated area so that a part of each area becomes a Japanese-style room. This feature allows transmission between terminals belonging to different low-speed networks using the Japanese-style room.

[Implementation S] Embodiments of the present invention will be described below based on the drawings.

Now, consider a case where two low-speed networks A and B are connected to the high-speed network 10 (FIG. 5), and one loop network 15 as shown in FIG. 3 is constructed. Both the high-speed network 10 and the low-speed networks A and B have a configuration in which transmission frames of a fixed length circulate on a loop. Note that 12 is a node of the high-speed network 10, and 3 is a node of the high-speed network 10.
0a.

30b is a node of low-speed network A or B, and subscripts a and b indicate that it belongs to low-speed network A or B, respectively.

The high-speed network 10 uniquely allocates a part of its own transmission frame for transmission by the two low-speed networks A and B, but in this case, the allocated areas for the plurality of low-speed networks A and B are each partially made up of a Japanese-style room. Assign as follows.

FIG. 1 shows an example of allocation of low-speed network areas in the transmission frame 20 of the high-speed network 10. 23 is the low-speed network A peripheral area, and 24 is the low-speed network B area.
This is a phase area 24, and both of them each have a portion of a Japanese-style room. Two low-speed networks A in this allocated area 23.24.

The transmission frame of B is loaded and actually transmitted on the loop by the high-speed network 10. When communicating between a terminal belonging to low-speed network A and a terminal belonging to low-speed network B, the area where the two areas overlap (
A-8 communication area) 25 is used for mutual communication.

In this case, the low-speed network A and the low-speed network B each need to recognize the same information about which terminal in the A-8 communication area 25 is used for communication. Therefore, there must be at least one place between the low-speed network A and the low-speed network B where information regarding the A-8 communication area 25 is exchanged.

By the way, if there are three low-speed networks A, B, and C, the simple method explained so far will determine the champion of the low-speed network A area, low-speed network B area, and low-speed network C area, However, as shown in FIG. 2, by distributing three areas for low-speed networks in the frame 20, transmission between terminals belonging to the emerging low-speed networks can be improved. becomes possible.

First, as shown in FIG. 2, the low-speed network A peripheral region 23 is defined as a first group consisting of three distributed regions 231, 232° 233, and the low-speed network B phase region 24 is defined as a first group consisting of three distributed regions 241, 242° 243. The low-speed network C area 26 is divided into three distributed areas 261,
The third group consists of 262°263. These A phase regions 23. B phase region 24. The respective dispersion intervals of the C regions 26 are set such that, for two different groups among the first, second, and third groups, one of the dispersion regions of each group overlaps with each other. assign.

In the case of the embodiment shown in FIG. 2, the first group of dispersion regions 23
1,232,233 and second group dispersion area 241.242
, 243, the dispersed areas 232 and 242 overlap, and the second group of dispersed areas 241, 242, 243 and the third group overlap.
The dispersion regions 243 and 263 overlap between the dispersion regions 261, 262 and 263 of the group, and the dispersion region 2 of the third group
61.262.263 and first group dispersion area 231.23
2.233, the distributed regions 261 and 231 are arranged in a distributed manner so as to overlap. By distributing and allocating the areas for low-speed networks in the frame 20 in this manner, the area for communication between networks A and B 25°, the area for communication between networks B and C 27. It becomes possible to provide an area 28 for communication between networks C and A within each frame. Note that the distributed area 233 is used as a network A exclusive area, the distributed area 241 is used as a network B exclusive area, and the distributed area 262 is used as a network C exclusive area.

The above was a case where there were three low-speed networks A, B, and C, but the same logic holds true even when there are four or more low-speed networks. Therefore, it is possible to transmit between terminals belonging to different low-speed networks in the same way. It can be done.

[Effects of the Invention] As explained above, according to the present invention, even when a plurality of low-speed networks are connected to a high-speed network, transmission between terminals belonging to the emerging low-speed networks becomes possible, and the system as a whole becomes more flexible. and expandability.

[Brief explanation of drawings]

FIG. 1 is an allocation diagram within a transmission frame when there are two low-speed networks in one embodiment of the present invention, FIG. 2 is an assignment diagram within a transmission frame when there are three low-speed networks according to another embodiment of the present invention, and FIG. Figure 3 is a general configuration diagram of a loop network in which two low-speed networks are connected to a high-speed network, Figure 4 is a diagram of the conventional transmission frame allocation in the loop network of Figure 3, and Figure 5 is a diagram showing a high-speed network and a low-speed network. A general configuration diagram of a combined loop network, FIG. 6 shows a conventional intra-transmission frame allocation diagram in the loop network of FIG. In the figure, 10 is a high-speed network, 11 is a low-speed network, 12 is a high-speed network node, 13 is a low-speed network node, 20 is a transmission frame of the high-speed network, 21 is an allocated area for the low-speed network, 22 is a frame header, and 23 is a frame header. Allocated area for low-speed network A, 2
4 is an allocated area for low-speed network B, and 25 is an area for communication between A and 8. Patent applicant: Hitachi Cable Co., Ltd. Representative Patent Attorney Nobuo Kinutani

Claims (1)

[Claims] 1. It consists of a combination of two types of loop networks with different transmission speeds in which transmission frames of a certain length circulate on loops, and the first loop network with a higher transmission speed transmits a part of the self-transmission frame. The second loop network, which has a lower speed, is uniquely allocated for transmission, and the second loop network places its own transmission frame in the allocated area, and the actual transmission is carried out on the loop by the first loop network. In the loop network to be transmitted, when there are a plurality of second loop networks connected to the first loop network, the first loop network divides the allocated areas for the plurality of second loop networks so that a portion of each of the second loop networks overlaps. A loop network characterized by assigning to.