JPH04150636A - Selective multiple address communication system - Google Patents

Abstract

PURPOSE:To eliminate the need for a long address different from that in the case of adoption of a group address by executing selective multiple address communication with a bit map header having a same bit number as that of number of nodes. CONSTITUTION:The network system consists of a network 1 enabling plural nodes 21-28 connected in a ring to be inter-communicated. In this case, a bit map provided in a multiple address frame and comprising plural bits corresponding to each of nodes in the network 1 is employed to designate a node to receive the multiple address frame. Thus, plural specific destination nodes are designated without need of a long address.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a selective synchronization system in which frames are simultaneously transmitted to a plurality of specific stations (herein referred to as r-nodes) in a network. Concerning communication methods.

[Prior Art] Conventionally, in a network, in a group broadcast communication method in which frames are sent to and received from multiple specific nodes at the same time, nodes connected to the network have an individual address and a shared address among multiple nodes. It had a group address, and by specifying destinations using this group address, it was possible to send to multiple specific notes at the same time.

Broadcast communication technology is described in the ``Data Communication Handbook'' (edited by the Institute of Electronics and Communication Engineers, Ohmsha), etc.

[Problems to be Solved by the Invention] However, according to the above-mentioned prior art, if group addresses are provided for all combinations of nodes connected to the network, group addresses for those combinations are required, and the number of nodes increases. When there are many addresses, the number becomes enormous, resulting in long addresses, and the management and processing thereof becomes complicated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a selective broadcast communication method that can easily specify a plurality of specific destination nodes without requiring a long address.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a selective broadcast communication system that simultaneously transmits the same broadcast frame to a plurality of specific nodes in a network, A selective broadcast communication method is characterized in that the nodes that should receive the broadcast frame are specified using a bitmap provided in the broadcast frame and made up of a plurality of bits each corresponding to each node in the network. provide.

[Function] According to the selective broadcast communication method according to the present invention, when performing selective broadcast communication, the transmitting side node uses one broadcast frame to indicate a plurality of nodes that wish to perform broadcast communication in its bitmap. When a unilateral node that sets and transmits a broadcast frame receives a broadcast frame, it checks whether the bit corresponding to its own node in the bitmap is set, and if it is set, it transmits the broadcast frame. If the frame is not set, the frame is discarded.

As a result, the broadcast frame will be received only by the nodes that the sending node has set in its bitmap.

As described above, according to the broadcast communication system according to the present invention, broadcast communication can be selectively performed to any combination of nodes using a bitmap having the number of bits equal to the number of nodes in the network. Therefore, the address does not become very long, and since the bits of the bitmap correspond to the nodes on a one-to-one basis, their management and processing can be performed easily.

[Example 1] An example of the selective broadcast communication system according to the present invention will be described below.

FIG. 1 is a block diagram showing the configuration of a network system according to this embodiment.

The system shown in FIG. 1 is a network 1 in which a plurality of nodes 21 to 2° are connected in a ring shape and communicate with each other.

The operation of the selective broadcast communication system according to this embodiment will be described below.

Now, in FIG. 1, node 2. However, node 21, node 26.2 . Assume that a broadcast frame is transmitted to.

In this embodiment, a bitmap header indicating which nodes should receive the frame is provided in this broadcast frame.

Then, nodes 21, 26 . . . in this bitmap header. Node 2. The corresponding bit is set to specify that the received frame should be received.

Since the frame transmitted by node 2□ is a broadcast frame, all nodes 2, including node 21. ~2° receives this frame.

When each node 21-2° that receives the frame recognizes that the frame is a broadcast frame, it checks the bitmap header in the broadcast frame.

Checked results Node 22, Node 25, Node 28
receives this frame because the bit corresponding to its own node is set.

Other nodes 21, node 2□, node 2. , node 26
, node 7 discards the received broadcast frame because the bit corresponding to its own node is not set.

As described above, in this embodiment, selective broadcast communication is achieved by the source node using the bitmap in the broadcast frame to set a bit indicating which nodes should receive the frame.

Next, each node will be explained.

FIG. 2 shows the configuration of the broadcast communication function section of the node device 2. As shown in FIG.

As shown in the figure, the node device 2 includes a transmission instruction mechanism 3, a transmission frame creation mechanism 4, a transmission mechanism 5, a reception mechanism 6, a broadcast check mechanism 7, a bitmap check mechanism 8, and a reception notification mechanism 9.

When the node 2 transmits a selective broadcast frame, the transmission instruction mechanism 3 in the node 2 instructs the transmission frame creation mechanism 4 to select which node should receive the broadcast, and the transmission frame creation mechanism 4 Create a broadcast frame, set the bit corresponding to the designated nine nodes in the bitmap header to indicate which node in the broadcast frame should receive it,
The transmitting mechanism 5 is instructed to transmit, and the transmitting mechanism 5 performs a frame transmitting operation.

Since the transmitted frame is a broadcast frame, all nodes receive the frame.

Since the frame on the transmission path is a broadcast frame, the reception mechanism 6 of the node 2 receives this frame and passes it to the broadcast check mechanism 7. The broadcast check mechanism 7 determines whether the received frame is broadcast or individual. If it is an individual frame, it is passed to the reception notification mechanism 9, and if it is a broadcast frame, it is passed to the bitmap header checking mechanism 8.The bitmap header 1298 mechanism checks the bitmap header and determines whether the relevant bit is set. If so, this frame is passed to the reception notification mechanism 9.

If the bit is not set, the bitmap header check mechanism 8 discards this broadcast frame.

As described above, according to the node device according to this embodiment, complicated control is not required because it can be realized only by manipulating and checking the bits of the receiving node in the bitmap. Furthermore, since each bit and each node in the bitmap correspond to one entity, it is easy to manage them.

Next, the configuration of the broadcast frame used for selective broadcast communication in this embodiment will be shown.

FIG. 3 shows the frame format of a broadcast frame flowing on a network transmission path.

As shown in the figure, the broadcast frame consists of a header of 10°, broadcast bits of 11, and a bitmap of 12.1nfoi- ation.

The bit map 12 has bits 12□ to 12n corresponding to each node address.

As explained earlier, node 2. (node N0゜1) is node 23 (node No. 3), node 25 (node N
0.5), node 2. (Note no.

When transmitting a frame to node 2.8), node 2. The transmission instruction mechanism 3 (see FIG. 2) instructs selective broadcasting, and the transmission frame creation mechanism 4 that receives the selective broadcasting instruction sets the broadcast bit 11 in the frame shown in FIG. 3 to 1. 12 of 12 to bitmap. (corresponding to node No. 3), 12S
(corresponding to node No. 5), set 1 to 12O (corresponding to node No. 0.8), and transmit.

Since this frame is a broadcast frame (the broadcast bit in FIG. 3 is set), each node 21 to 28 receives the frame at the receiving mechanism 6 and passes it to the broadcast check mechanism 7. Since the broadcast bit is set, each node uses the bitmap header check mechanism 8 to check the bit corresponding to its own node.

In this case, node 23, node 2 and node 2. The bit corresponding to the own node is set (12..12..12 in the bit map 12 in Figure 3 is set)
Therefore, node 23. Node 2s, node 2. This frame is then passed to the receiving mechanism 9.

Other nodes (nodes 2□, 2□, 24, 26, 27) discard the received frame because the relevant bit is not set.

As described above, according to this embodiment, in order to realize selective broadcast communication using a bitmap header with the same number of bits as the number of nodes, a long address can be used as in the case where the group address is used. It will never be necessary.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a selective broadcast communication system that can easily specify a plurality of specific destination nodes without requiring a long address.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a network system according to an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of a broadcast communication function section of a node device, and FIG. 3 is a block diagram showing the configuration of a broadcast communication function section of a node device. FIG. 2 is an explanatory diagram showing a frame format of FIG. 1... Network, 21-2. ...Node 3...
- Transmission instruction mechanism, 4... Transmission frame creation mechanism, 5.
... Transmission mechanism, 6... Receiving mechanism, 7... Broadcast check mechanism, 8... Bitmap header check mechanism, 9...
...Reception notification mechanism, 10...Frame, 11...Broadcast bit, 12□ to 12n...Bitmap header. Applicant: Hitachi, Ltd. (and 2 others)

Claims (1)

[Scope of Claims] 1. A selective broadcast communication method that simultaneously transmits the same broadcast frame to specific nodes in the network, wherein each node in the network is provided in the broadcast frame. 1. A selective broadcast communication system characterized by specifying a node that should receive a broadcast frame using a bitmap consisting of a plurality of bits each corresponding to a broadcast frame.