JPH0818555A - Multiple address communication link control method - Google Patents

Abstract

PURPOSE:To extend the selection branches of identification by identifying multiple address communication based on the combination between a transmission logical number and an intermediate logical number. CONSTITUTION:A transmission station 1 opens a multiple address communication link and selects and sets an idle number among 0-127 as a transmission logical number and selects and sets an idle number among 0-127 as an intermediate logical number, uses the combination of both the logical numbers to set identification of the multiple address communication and sends a transmission request 201 to each of reception stations 2, 3,... for multiple address communication. Each of the reception stations 2, 3,... allocates a reception logical number of a concerned station corresponding to the combination between the transmission logical number and the intermediate logical number to return a reply 202 corresponding to a transmission request 201. A count discrimination means 203 of the transmission station 1 counts number of stations returning the reply 202 with respect to the transmission request and compares the number with a preset threshold level. When number of the stations returning the reply 202 exceeds a threshold level, the transmission station 1 starts multiple address communication.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broadcast logical link control device for controlling link connection in broadcast data communication.

[0002]

2. Description of the Related Art Conventionally, link control is to assign a logical address of a data link layer.
LLC (Logical Link) defined in 2.2.
Control) is well known. Also, in group broadcasting of broadcast communication, an example in which a header of group information is generally added to the head of data and transmitted is known. In this LLC, Service Access P
It is possible to configure a logical link based on a point (SAP). Managing broadcasts using this SAP allows a plurality of broadcasts to exist in one communication medium at the same time, and enables the operation of broadcasts in a mesh network. However, if a one-to-one logical link with each receiving station is set for each broadcast communication, the communication overhead will increase by itself, and the broadcast transmitting station will have a logical link for all receiving stations. It is very burdensome to manage them individually. This is because an attempt was made to directly apply a logical link considered for one-to-one communication to broadcast, and a logical link for broadcast is originally desired.

[0003]

In the prior art link control, when performing broadcast communication, the transmitting station must establish a logical link with each receiving station individually for one broadcast link. There was a problem that required a lot of link management. Further, when performing group broadcasting, there is a problem that the transmission efficiency is reduced because group information is always added to the head of the broadcasting data.

The present invention proposes a new method for setting a broadcast logical link, in which both a broadcast transmitting station and a receiving station set only one logical link for one broadcast communication with each other. Trying to solve.

[0005]

In order to solve the above-mentioned problems in the present invention, the first invention is a system in which a broadcast transmitting station and a plurality of broadcast receiving stations are connected by a broadcast medium. In the broadcast link control method, when a link is opened, a transmission logical number and an intermediate logical number are added to a broadcast transmission request, and the broadcast transmission request is transmitted to the plurality of broadcast receiving stations, The broadcast receiving station individually assigns a reception logical number to the broadcast transmission request command in correspondence with the set of the logical number and the intermediate logical number, and the broadcast receiving station transmits the broadcast logical number. The number of stations that responded to the transmission request and returned a response from the broadcast transmitting station was counted, and it was determined whether the counted number of stations exceeded a certain value. The feature is that information transmission is started.

Also, in the second invention, when the number of stations that have returned the response does not exceed a set threshold value, the broadcast transmitting station adds the request count to the transmission request, and a certain period of time is added. If the number of responses received within does not exceed the threshold,
The transmission request is repeatedly transmitted.

In a third aspect of the present invention, broadcast group information is added to the transmission request, and it is determined whether or not the transmission request is a transmission signal for broadcast communication directed to the own station based on the group information, When it is determined that the mobile station is directed to the own station, a reception logical number is assigned.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a block diagram for implementing the present invention. In FIG. 1, a transmitting station 1 and receiving stations 2 and 3 are connected via a broadcast medium 4. Hereinafter, details of the operation of the present invention and an embodiment will be described.

In the first invention, a broadcast link is set by using a new intermediate logical number for mediating between logical numbers exchanged between transmission and reception in connection of the broadcast link. is there. Further, the value of the broadcast is determined based on the number of responses from the receiving station, and if the broadcast is worthwhile, the broadcast transmission is started.

The overall sequence is shown in FIG. In response to the transmission request 201, each receiving station returns a response 202. The transmitting station receives this and processes the judging means for comparing the counting means for counting the number of stations which have returned a response with the threshold value.
After 3, if the threshold is exceeded, the broadcast is started.

FIGS. 3 and 4 show a flowchart on the transmitting side and a flowchart on the receiving side, respectively. The transmitting side starts by triggering the start of broadcasting, and first selects a logical number of the transmitting side from a group of transmitting logical numbers that are not currently used, and thereafter adds the logical number to be used for identification of the broadcast transmission. Processing 301 is performed. Subsequently, a process 310 of selecting and adding from the intermediate logical number group in the same manner as the transmission logical number is performed. Thereafter, the transmitting side limits the identification of the broadcast to only those having the same set of the transmission logical number and the intermediate logical number selected here. Then, step 302 of transmitting these to the receiving stations as transmission requests is processed. Then, the process of step 303 of starting a timer for making a waiting time until the reception response is returned is performed, and the response from the receiving station is searched 305 until a timeout occurs at the determination step 304, and every time the response is received, Process step 306 of incrementing the counter by 1. After the time-out, it is determined 307 whether the value of the counter exceeds the threshold value.

As shown in FIG. 4, the part of the broadcast start process on the receiving side includes a step 401 of waiting for a transmission request and a step 402 of judging whether or not the own station has an unused logical number when the transmission request is received. The step 403 is to assign a reception logical number by associating an unused logical number with a set of a transmission logical number and an intermediate logical number added to a transmission request, and transmitting a "response" to the transmission.

[0013] The second invention is the first invention in addition to the first invention.
When the number of responses does not become equal to or greater than the set threshold value according to the invention, the determination process from point A to point B in FIG. 3 is replaced as shown in the sequence of FIG.

A step 501 for adding the request count is added to the transmission request, and when the received response signal does not exceed the threshold value in the judgment step 307 within a fixed time, the repeated transmission request is transmitted. In the embodiment shown in FIG. 5, the number of repetitions is n. Each time the receiving station receives the transmission request, it adds the number of requests added to the transmission request to the response and transmits the response. If the number of responses is small, the number of requests is increased. The logical number is a logical number used in the IEEE802.2 LLC, for example, 0
128 × 12
There are eight combinations.

A third invention is a broadcast link control for performing a group broadcast. As shown in FIG. 6, a step 601 for adding broadcast group information is provided as information to be added to the transmission request of the first invention or the second invention. When assigning a logical number, the receiving station has a step 602 for judging from the group information whether the request is a transmission request for a broadcast directed to the own station. Step 4 for assigning logical numbers
Go to 02. As a method of creating group information, data having a bit length corresponding to the number of system stations is prepared, and each bit is uniquely assigned to a certain receiving station. Then, when broadcasting a certain group, only the bit corresponding to the receiving station is set to 1 and added to the transmission request. On the receiving side, a logical number is assigned only when the state of the bit corresponding to the own station is 1.

[0016]

According to the present invention, there is an effect that a plurality of broadcasts can be transmitted simultaneously by identifying a plurality of broadcasts by a logical number when the broadcast is performed. Also, because the intermediate logical number was used,
Assuming that each logical number has a table of 128, there are only 128 × 128 options, which is also effective for the problem that logical numbers overlap.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of the present invention.

FIG. 2 is a diagram showing a flow of a procedure according to the embodiment of the first invention.

FIG. 3 is a flowchart of the transmitting side of the first invention.

FIG. 4 is a flowchart on the receiving side of the first invention;

FIG. 5 is a flowchart added to the transmission side of the first invention of the second invention.

FIG. 6 is a flowchart added to the first invention of the third invention.

[Explanation of symbols]

 1 transmitting station 2, 3 receiving station 4 broadcast medium

Claims (3)

[Claims] 1. In a broadcast link control method in a system in which a broadcast transmitting station and a plurality of broadcast receiving stations are connected by a broadcast medium, a broadcast logical number is transmitted to a broadcast transmitting request when a link is opened. And an intermediate logical number are added, the broadcast transmission request is transmitted to the plurality of broadcast receiving stations, and the broadcast receiving station sends a logical number and an intermediate logical number to the broadcast transmission request command. The broadcast receiving station individually assigns a reception logical number corresponding to the group, and the broadcast receiving station responds to the broadcast transmission request, and determines the number of stations that returned a response at the broadcast transmitting station. A broadcast link control method comprising counting, determining whether the counted number of stations exceeds a certain value, and starting broadcast transmission when the determination exceeds a threshold value. 2. The number of replies received within a certain period of time, when the number of stations that has returned the response does not exceed a set threshold value, the broadcast transmitting station adds the number of requests to the transmission request. The broadcast link control method according to claim 1, wherein the transmission request is repeatedly transmitted when the value does not exceed the threshold value. 3. A broadcast group information is added to the transmission request, and it is determined by the group information whether or not the signal is a transmission signal for broadcast communication directed to the own station. The broadcast logical link control method according to claim 1 or 2, wherein a received logical number is assigned when the determination is made.