JPS62200838A - Multiple address message transmission/reception system - Google Patents

Abstract

PURPOSE:To improve the transmission efficiency by providing the 1st transmission means forming the transmission, the 2nd transmission means sending a multiple address frame onto a transmission line and a reception means receiving the multiple address frame and informing in advance the presence of the sending of a multiple address message to plural optional stations. CONSTITUTION:The multiple address frame is sent independently to a bus type transmission line 1 from data sending stations STN2b, 2a respectively. Multiple address frame numbers B1, B2 are set to the address field AD of the multiple address frame. When the remaining it except a frame kind designation bit S is coincident with a multiple address frame number formed by the sequence S1 or S2, stations STN3a, STN3n receive the same frame selectively. Thus, the multiple address frame from the station STN2b is received by the stations STN3a, 3b at the same time, and the multiple address frame from the STN2a is received at the same time by the STNs 3c, 3d. Since the same message is sent to plural optional stations STNs by the multiple address, the transmission time is reduced remarkably.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a data transmission system in which frame data including a destination address field and an information field is transmitted via a transmission path. The present invention relates to a broadcast message transmission/reception system that enables broadcast message delivery to any number of stations.

(Prior Art) In a data transmission system such as a local area network, when transmitting the same message to multiple stations, a broadcast frame with a broadcast address or group address defined in the destination address field is used. It will be done.

Although the above method can be applied to broadcast transmission to all stations in a system or to all stations in a predetermined group, it cannot be applied to broadcast transmission to arbitrary plurality of stations. For this reason, in the past, in order to transfer a message to any number of stations, the same message had to be sent to each station individually, which resulted in a problem of poor transmission efficiency.

(Problems to be Solved by the Invention) Therefore, an object of the present invention is to solve the above-mentioned conventional problem of not being able to broadcast messages to arbitrary multiple stations, and to provide a multicast system that can improve transmission efficiency. The objective is to provide a system for transmitting and receiving information messages.

[Structure of the invention] (Means and effects for solving the problem) In this invention,
a first transmitting means for transmitting a delivery notification frame to notify in advance that a broadcast message will be delivered to any plurality of stations that require broadcast message delivery;
A second transmitting means for transmitting the broadcast frame and a receiving means are provided. A broadcast frame identifier for identifying the broadcast frame constituting the broadcast message is set in the information field of the delivery frame transmitted by the first transmitting means. When the second transmitting means finishes transmitting the delivery notification frame, it sends out onto the transmission path a broadcast frame in which a broadcast frame identifier is set in the destination address field and a broadcast message is set in the information field. The broadcast frame on this transmission path is received by the receiving means only at the station that receives the delivery notification using the delivery notification frame in which the same broadcast frame identifier as the broadcast frame identifier set in the destination field is set. be done.

As described above, in this invention, by notifying any plurality of stations that require broadcast message delivery in advance, it becomes possible to broadcast a message to any plurality of stations, and send the message. Increased efficiency. Further, by using a delivery notification frame in which a predetermined value indicating a delivery notification frame is set in the destination address field and station addresses of the plurality of stations described above are set in addition to the above-mentioned broadcast frame identifier in the information field. It is also possible to transmit the delivery notification frames all at once, and in this case, the transmission efficiency can be further improved.

(Embodiments) a. First Embodiment FIG. 1 shows a block configuration of a data transmission system, for example, a local area network, according to an embodiment of the present invention. In the figure, 1 is a bus type transmission line, 2a, 2b
, 3a, 3b, 3c, 3d, and 3n are stations (hereinafter referred to as
(referred to as STN).

FIGS. 2(a) to 2(C) show data frame formats applied in the local area network of FIG. 1. This frame is HDLC (High Level
Data Line Control>Flag field for synchronizing frames Address field A indicating the destination address (destination address) Address field As indicating the source address (source address), user information The information field 11 used for the transfer of the frame consists of a frame check sequence FC8, which is an error checking field, and a flag field F, which indicates the end of the frame.

The first bit of the address field Ao is used as a frame type designation bit S indicating whether the corresponding frame is an individual transmission frame or a broadcast transmission frame (here, a broadcast frame or a broadcast message). Frame type designation pit S specifies the individual transmission frames shown in FIGS. 2(a) and (b) in S-0, and the broadcast transmission frame (broadcast frame) shown in FIG. 2(C) in S-1. show.

In the case of S-〇, the remaining bits of the address field Ao are the address (STN address, individual destination address) of the destination STN (station) of the frame (individual transmission frame), as shown in Figure 2 (a) and (b). ) used for designation. In this case, the predetermined bit at the beginning of the information field I is used as the command field CMD. The command used in the command field CMD is the second
As shown in Figure (a), the remaining field following the command field CMD of the information field I is a command CMDI indicating that it is a broadcast frame number, and the second factor (b).
As shown in the figure, the command CMD2 is broadly divided into the command CMD2, which indicates normal data (text). The above broadcast frame 11@ is an identifier for identifying a broadcast frame to be delivered to arbitrary plurality of 5TNs (stations). Therefore, the command CMDI also indicates that the corresponding frame is a broadcast frame delivery notification frame for notifying the delivery of a broadcast frame.

In the case of S-1, the remaining bits of the address field An are used to designate a broadcast frame number for identifying the relevant frame (broadcast frame), as shown in FIG. 2(C). In this case, the information field ■ is used for normal data (text, broadcast message) transmission.

Next, the operation of one embodiment of the present invention will be described as S T N 2a
S T N 2b broadcasts the same message (broadcast frame) indicated by broadcast frame number B1 to 5TN3a and 3b, and another same message (broadcast frame) indicated by broadcast frame 1iQB2 is transmitted from S T N 2b to 5TN3c and 3d. The case of broadcasting a broadcast frame) will be explained with reference to the transmission/reception sequence chart in FIG.

First, as shown in sequence S1 in FIG. 3, 5TN2b transmits the delivery notification frame shown in FIG. , 3b, the address field Ao (the remaining fields excluding the frame type designation bit S) of the delivery notification frame for 5TIla, 3b, which is the destination of the same frame, contains the address (STN address) of 5TIla, 3b, which is the destination of the same frame.
Each is set.

Further, the command CMDI and the broadcast frame number B1 are both set in the information field 1 of the delivery notification frame for the 5TNs 3a and 3b.

5TN3a connects S T N 2a via bus type transmission line 1.
If the frame transmitted by T
N 3a address), the same frame is received. Then, S T N 3a refers to the command field CMD of the information field I of the received frame, and if command CMD1 is set as in this example, the corresponding frame is a delivery notification frame that notifies the delivery of the broadcast frame in advance. Assuming that the information in the remaining fields of field I is the broadcast frame number, the same rI
No. I (here, 81) is held internally. The above is S
The same applies to N 3b, and broadcast frame number 8
1 is held in S T N 3b.

Similarly, S T N 2a is the sequence S2 of FIG.
As shown in FIG. 2A, the delivery notification frame shown in FIG. Address field Ao (frame type designation bit S of the delivery notification frame for these 5TN3c, 3d)
The addresses (STN addresses) of 5TN3C and 3d, which are the destinations of the same frame, are respectively set in the remaining fields (excluding 5TN3C and 3d).

Further, the command CMD1 and the broadcast frame number B2 are both set in the information field 1 of the delivery notification frame for 5TN3C and 3d.

By transmitting the delivery notification frame of sequence S2 described above, the broadcast frame number B2 is held in 3TN3C, 3d.

Next, the broadcast frame shown in FIG. 2(C) is sent out onto the bus-type transmission line 1 from the 5TNs 2b and 2a independently, as shown in sequences 83 and 84 in FIG. 3. 5T
Broadcast frame number 81 (82) is set in the address field AD (the remaining fields excluding the frame type designation bit S) of the broadcast frame sent from N2b (2a). In S T N 3a to 3n, the frame on the bus-type transmission line 1 is a broadcast frame, and the remaining bits excluding the frame type designation pit S (5-1 in this case) of the address field Ao are S1 or S2. The frame is selectively received only when it matches the broadcast frame number notified in the sequence. therefore,
In this example, the broadcast frame from S T N 2b is
5TN3a and 3b simultaneously received, S T N 2a
Broadcast frames from 5TN3C and 3d are received simultaneously. If the number of messages to be transmitted is larger than the amount of data that can be transmitted in one broadcast frame, the broadcast frame is repeatedly transmitted as shown in FIG.

According to the above method, since the same message can be broadcasted to any number of STNs, the transmission time can be significantly reduced compared to the conventional method in which the message was sent to each STN individually. In addition,
For this broadcast transmission, it is necessary to individually transmit the delivery notification frame shown in FIG. 2(a) to the destination STN. However, since the length of the delivery notification frame is significantly shorter than the frame for sending a message (text), there is little possibility that the effect of shortening the time required to send a message will be adversely affected. .

b. Second Example Next, regarding the above-mentioned example in which the notification of delivery was made more efficient, reference will be made to FIG. The frame format will be explained with reference to the sequence chart in FIG.

Fourth factors (a) to (C) indicate the format of the data frame applied in this embodiment (second embodiment). This frame conforms to the HDLC procedure like FIGS. 2(a) to 2(C).

The first bit of the address field Ao is used as a frame type designation pit S indicating whether the corresponding frame is an individual transmission frame or a tip transmission frame.

This broadcast transmission frame includes a delivery notification frame in addition to a broadcast frame (broadcast message frame). The frame type designation pit S specifies the individual transmission frame shown in 41ffl(a) in S-0, and the individual transmission frame shown in FIG. 2(b) and (C) in S-1.
Figure 2 shows the broadcast transmission frame shown in Figure 2.

In the case of S-O, the remaining bits of the address field An are used to address the destination STN of the individual transmission frame, as shown in FIG. 4(a). In this case, the information field ■ is used for normal data (text) transfer. .

In the case of S-1, if the remaining bits of the address field AD are all "0" as shown in Figure 14(b), it specifies that the corresponding frame is an acknowledgment frame in the broadcast transmission frame, and Otherwise, the frame in question is a broadcast frame among broadcast transmission frames, and is used to designate the corresponding broadcast frame number as shown in FIG. 4(C).

In the case of a delivery notification frame, a predetermined bit at the beginning of the information field I is used to designate a broadcast frame number to identify a broadcast frame to be delivered to arbitrary multiple STNs,
The remaining bits are used to specify the addresses of the plurality of STNs (<STN address). In the case of a broadcast frame, the information field (2) is used for normal data (text, broadcast message) transmission.

Now, S T N 2a to S T N 3a, 3b
1. :On the other hand, it is assumed that a broadcast frame (return frame message) indicated by broadcast frame number B (B≠O) is broadcast and transmitted. In this case, in this example, 5TN2a
uses the delivery notification frame shown in FIG. 4(b) to transmit the broadcast frame with broadcast frame number B to 5TN3a, 3
It is necessary to notify b in advance. So S T N 2a
First, it generates the delivery notification frame shown in FIG. 4(b) in which the broadcast frame number B and the STN addresses of 5TN 3a and 3b are set in the information field I, and sends it onto the bus-type transmission line 1.

Each STN other than S T N 2a, i.e. 5TN2b, 2
a to 2n, when the frame on the bus-type transmission path 1 is a delivery notification frame, that is, the frame type designation bit S of the address field Ao is "°1" and the remaining bits are all "0".
'' frame, the same frame is received, and it is determined whether an address indicating the own STN (STN address) is set in the area following the broadcast frame number (in this case B) specified area of the information field I. Find out. In this example,
The addresses of 5TN3a and 3b are set in the above bright area. When the 5TNs 3a and 3b detect that their own STN address is set in the delivery notification frame,
It is determined that this frame is the delivery notification of the broadcast frame specified by the broadcast frame number B set in the first area of the information field I, and the broadcast frame number B is held internally. On the other hand, 5TN2b, 3c to 3d detect that the address of their own STN is not set in the delivery notification frame, so this frame is
It is determined that this is not a delivery notification of a broadcast frame addressed to N,
This frame is numbered 11. In other words, the S T N 2a broadcasts the delivery notification only to the 5TNs 3a and 3b, which are the destinations of the broadcast message.

Next, 5TN2a sends a broadcast frame (broadcast frame message) having the frame structure shown in FIG. Send on 1.

In the address field Ao of this broadcast frame, a frame type designation pit S of logic "1" and a broadcast frame number 8 are set.

Each STN other than S T N 2a, i.e. 8th N2b, 2
8 to 2n indicate that the frame on the bus-type transmission line 1 is a broadcast frame, that is, the frame type designation bit S of the address field AD is "1" and the remaining bits are other than all "0" indicating the broadcast frame number. In the case of a frame, the frame is selectively received only when the remaining bits (broadcast frame number) match the broadcast frame number (here B) notified in advance in the delivery notification frame. In the example, the broadcast frame from 5TN2a is sent to 8th N3a.

3b is received at the same time. That is, S T N 2a
The broadcast frame indicated by the broadcast frame number B is 5T
This means that the broadcast was sent only to N3a and 3b.

[Effects of the Invention] As detailed above, according to the present invention, by notifying any plurality of stations that require broadcast message delivery in advance, it is possible to send a broadcast message to any plurality of stations. It becomes possible to broadcast messages and improve transmission efficiency. Furthermore, by notifying the delivery of a broadcast message using a broadcast frame identifier for identifying a broadcast message, and by setting this broadcast frame identifier in the destination address field of the broadcast frame and transmitting the broadcast frame, Different broadcast frames can be transmitted to different stations in parallel.

[Brief explanation of drawings]

FIG. 1 shows block components showing a local area network according to a first embodiment of the present invention, and FIGS. 2(a) to (C)
) is a diagram showing the frame format applied in the first embodiment, FIG. 3 is a transmission/reception sequence chart for explaining the operation of the first embodiment, and FIGS. 4(a) to (C)
is a diagram showing a frame format applied in the second embodiment of the present invention, and FIG. 5 is a transmission/reception sequence chart for explaining the operation of the second embodiment. 1... Bus type transmission line, 2a, 2b, 3a to 3n.
...Station (STN). Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2

Claims (2)

[Claims] (1) In a data transmission system in which frame data including a destination address field and an information field is transmitted via a transmission path, a broadcast message is sent in the information field to any number of stations that require broadcast message delivery. a first transmitting means for individually transmitting a delivery notification frame in which a frame identifier is set in advance to notify delivery; and a broadcast message in which the broadcast frame identifier is set in the destination address field and the information field is set. a second transmitting means for transmitting a broadcast frame on the transmission path in which the broadcast frame is set, and the broadcast frame identifier is set in the destination field of the broadcast frame on the transmission path transmitted by the second transmission means; receiving means for receiving the broadcast frame on the transmission path only at the station that has received a delivery notification based on the delivery notification frame in which the same broadcast frame identifier as the broadcast frame identifier is set. Broadcast message sending and receiving method. (2) In a data transmission system in which transmission of frame data including a destination address field and an information field is performed via a transmission path, a delivery notification is sent in the destination address field to any plurality of stations that require broadcast message delivery. a first transmitting means for notifying delivery by transmitting in advance a delivery notification frame in which a predetermined value indicating a frame is set and a broadcast frame identifier and station addresses of the plurality of stations are set in the information field; a second transmitting means for transmitting, onto the transmission path, a broadcast frame in which the broadcast frame identifier is set in the destination address field and a broadcast message is set in the information field; If the broadcast frame identifier is set in the destination field of the broadcast frame on the transmission path, the above broadcast frame receives a delivery notification using the delivery notification frame with the same broadcast frame identifier set as this identifier. 1. A broadcast message transmission and reception system, comprising a receiving means for receiving broadcast frames on the transmission path only in a station.