JPH1188396A - Communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication equipment capable of balancing a tree when certain conditions are satisfied and the balance of the tree is destroyed such as the time when the number of slave equipments managed by the present equipment exceeds a fixed number. SOLUTION: This communication equipment is constituted of a data transfer control part 1, a delivery confirmation control part 4, a re-transmission request control part 5, a tree structure control part 6, a network interface part 3 and a management table 2. In order to change a tree structure corresponding to the number of the managed equipments and the state of a communication path between managed equipments, the tree structure control part 6 transmits management information to the other equipment, and at the time of receiving the management information, registers it in the management table 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device for performing broadcast communication between devices connected to a network.

[0002]

2. Description of the Related Art When exchanging data information between communication apparatuses, unlike voice information and image information transmitted in real time, data information cannot be lost or reversed in order, so that error-free communication is performed. There is a need to do. Here, data refers to information that constitutes one operation or meaning in one unit, and refers to, for example, an electronic file (a character file, a sound file, an image file, a program, etc.) of a computer.

[0003] A device that has received data information transmits an acknowledgment packet (hereinafter, referred to as an "ACK packet") in order to inform the source device that the data has been correctly received.

[0004] A transmission source device knows that transmission data has been correctly passed by receiving a delivery confirmation packet from a reception device. ACK after a certain time
If the packet does not arrive at the source of the data, the source device determines that the data was not passed correctly, transmits the data again, and waits for an ACK packet.

[0005] When the receiving side notices an error or lack of received data, it transmits a retransmission request packet (hereinafter referred to as "NAK packet") to inform the transmitting side that the data has arrived erroneously. There is also a method in which the transmitting side that has received the data retransmits the data.

[0006] When data is broadcast between a plurality of devices, the reliability of data is basically guaranteed by the above-described method.

However, as the number of devices increases, there is a problem that ACK packets and NAK packets are concentrated on data senders and the load becomes heavy.

Therefore, a logical tree structure is formed between devices belonging to a broadcast group (multicast group) with a data sender as a root, and an ACK packet or NA
A method in which K packets are transmitted toward a node (apparatus) in the root direction of the tree, and the node receiving the packet receives the ACK or NAK of the node on the branch side more than itself and retransmits the data. there were.

[0009]

Conventionally, this logical tree structure is such that, although nodes corresponding to the leaves of the tree are added or deleted, the nodes corresponding to the trunks are once formed in the tree. It was static, unchanged.

Therefore, even if the balance of the tree is poor and unbalanced, there is no means for reconstructing the tree in order to balance the tree. In that situation, there can be a large difference between the number of devices on the branch of one device and the number of devices on the branch of another device. There is no means for distributing the data to another device, which causes a decrease in the overall throughput.

Accordingly, the present invention provides a communication apparatus capable of balancing a tree when a certain condition is satisfied and the tree is out of balance, such as when the number of devices managed by the own apparatus exceeds a certain number. I will provide a.

[0012]

According to a first aspect of the present invention, there is provided a plurality of communication devices in which one or more child devices are provided so as to be able to communicate with each other in one parent device. A management information storage unit for storing management information including at least the acknowledgment information received from the child device; a parent device identifier storage unit for storing an identifier of a parent device managing the own device; All child devices stored in the information storage means, or information communication means for transmitting and receiving information to and from the parent device stored in the parent device identifier storage means, and a child transmitting information by the information communication means. From the device, acknowledgment means for performing acknowledgment of the transmitted information by comparing acknowledgment information indicating that the information has been received and the management information, and When you are reach confirmed, a communication apparatus characterized by having a delivery confirmation transmission means for transmitting the acknowledgment information to the parent device.

[0013] According to the communication device of the first aspect, it is possible to reliably confirm the delivery of information based on the management information, and to prevent erroneous transmission of information. Therefore, information can be reliably transmitted from the parent device to the child device.

[0014] The invention according to claim 2 is characterized in that when the delivery confirmation means cannot confirm delivery, or when retransmission request information indicating that information was not received correctly is received,
An information retransmission unit that retransmits the transmitted information as retransmission information, the information communication unit retransmits the retransmission information from the parent device to all child devices stored by the management information storage unit, 2. The communication according to claim 1, wherein the acknowledgment transmitting unit transmits the acknowledgment information to the parent device when the acknowledgment of the retransmission information from all the child devices is performed by the acknowledgment device. Device.

According to the communication device of the present invention, when it is not possible to confirm the delivery of the information based on the management information, the retransmission information is sent and the delivery is confirmed on the basis of the retransmission information. Information can be transmitted reliably.

According to a third aspect of the present invention, when the number of child devices stored in the management information storage means exceeds a reference, management information of a predetermined number of child devices is removed from the management information storage means, and the management information excluding the management information is excluded. The communication device according to claim 1, further comprising a management information transmitting unit that transmits information to another device, wherein the management information storage unit stores management information received from another device.

According to a third aspect of the present invention, when a certain condition is satisfied, such as when the number of child devices exceeds a reference, management information of any of the child devices is transmitted to the child device. The parent device, which has passed it to a small number of other parent devices, stores the management information and puts it under management, and also performs data transfer and delivery confirmation for the newly added child device. Such a configuration change is performed not only at the end of the tree but also between devices at the trunk.

Specifically, each device exchanges information regarding the child device and the parent device, and grasps what kind of tree structure is formed. In the tree, compare the number of child devices managed by the parent device at the same level as the own device with the number of child devices managed by the own device. The management information of an arbitrary child device is passed to another parent device, and the management is entrusted to reduce the difference between the management devices.

Therefore, the tree structure can be flexibly changed so that the load on each device is not biased due to a change in the number of groups and, for example, a certain device does not become a bottleneck, and data transfer and delivery can be performed efficiently. Confirmation can be performed.

According to a fourth aspect of the present invention, there is provided a communication method in a plurality of communication devices in which one or more child devices are provided so as to be able to communicate with each other in one parent device. An identifier and a management information storing step of storing management information including at least acknowledgment information received from the child device; a parent device identifier storing step of storing an identifier of a parent device managing the own device; All the child devices stored in the storage step, or, the information communication step of transmitting and receiving information with the parent device stored in the parent device identifier storage step,
From the child device that transmitted the information in the information communication step, a delivery confirmation step of comparing delivery management information and the management information indicating that the information was received to confirm delivery of the transmitted information, and the delivery confirmation step A communication confirmation transmission step of transmitting the transmission confirmation information to the parent device when the transmission confirmation of the transmitted information is completed.

According to a fifth aspect of the present invention, when the delivery confirmation is not possible in the delivery confirmation step, or when retransmission request information indicating that information was not correctly received is received, the transmitted information is retransmitted In the information communication step, in the information communication step, retransmit the retransmission information from the parent device to all the child devices stored in the management information storage step, in the delivery confirmation transmission step, 5. The communication method according to claim 4, wherein, when delivery confirmation is performed from all of the child devices in the delivery confirmation step with respect to retransmission information, the delivery confirmation information is transmitted to the parent device.

According to a sixth aspect of the present invention, when the number of child devices stored in the management information storage step exceeds a reference, management information of a predetermined number of child devices is removed from the management information storage step, and the management information excluding the management information is excluded. The communication method according to claim 4, further comprising a management information transmitting step of transmitting information to another device, wherein the management information storing step stores management information received from another device.

According to a seventh aspect of the present invention, there is provided a recording medium in which a communication method program used in a plurality of communication devices in which one or more child devices are provided so as to be able to communicate with each other is provided. A management information storage function for storing an identifier of a child device managed by the device, management information including at least acknowledgment information received from the child device, and a parent for storing an identifier of a parent device managing the own device. A device identifier storage function, an information communication function of transmitting and receiving information to and from all the child devices stored by the management information storage function, or the parent device stored by the parent device identifier storage function, and the information From a child device that has transmitted information by a communication function, an acknowledgment function for comparing acknowledgment information indicating that the information has been received with the management information and acknowledging the transmitted information And a recording medium for a program of a communication method, wherein the transmission confirmation function for transmitting the transmission confirmation information to the parent device when the transmission confirmation function can confirm the transmission of the transmitted information is recorded. is there.

The invention according to claim 8 is characterized in that when the delivery confirmation function fails to confirm delivery, or when retransmission request information indicating that information was not correctly received is received, the transmitted information is retransmitted information. The information retransmission function is recorded as retransmission, the information communication function retransmits the retransmission information from the parent device to all the child devices stored by the management information storage function, and the delivery confirmation transmission function is 8. The recording of the program of the communication method according to claim 7, wherein when the delivery confirmation function is performed from all the child devices with respect to the retransmission information, the delivery confirmation information is transmitted to the parent device. Medium.

According to a ninth aspect of the present invention, when the number of child devices stored by the management information storage function exceeds a reference, management information of a predetermined number of child devices is excluded from the management information storage function, and the management information excluding the management information is excluded. 8. The program according to claim 7, wherein a management information transmission function for transmitting information to another device is recorded, and wherein the management information storage function stores management information received from another device. Recording medium.

[0026]

Embodiments of the present invention will be described.

First Embodiment FIG. 1 shows an example of the configuration of a broadcast control device according to a first embodiment of the present invention.

In FIG. 1, a broadcast control device according to the present embodiment includes a data transfer control unit 1, a delivery confirmation control unit 4, a retransmission request control unit 5, a tree structure control unit 6, a network interface unit 3, a management table 2

Upon receiving data from a user or an upper layer application, the data transfer control unit 1 generates a data packet by adding a sequence number and the like to the data packet, stores the data packet in a transmission buffer, and then stores the data packet in a network interface unit. Send to 3. When a data packet is received from the network interface unit 3, the source address and the sequence number are checked, and the packet is stored in the reception buffer as necessary by referring to the management table 2, and the own device manages the packet. It sends an instruction to the acknowledgment control unit 4 to transmit the ACK packet, or sends an instruction to the retransmission request control unit 5 to transmit the NAK packet.

The delivery confirmation control unit 4 includes the data transfer control unit 1
In response to the instruction from, the management table 2 is checked to see how many data packets the own device has received,
An ACK packet is transmitted to a device (parent device) managing the own device.

The retransmission request control unit 5 includes a data transfer control unit 1
And sends a packet for requesting retransmission to the parent device.

The tree structure control unit 6 transmits management information to another device in order to change the tree structure according to the number of managed devices and the state of the communication path with the managed device. When the management information is transmitted or, conversely, received, the management information is registered in the management table 2.

The network interface unit 3 includes a data transfer control unit 1, a delivery confirmation control unit 4, a retransmission request control unit 5,
In response to the packet transmission request received from the tree structure control unit 6, a packet is transmitted to the network, or necessary information is extracted from the packet received from the network and passed to the data transfer control unit 1, the delivery confirmation control unit 4, and the like.

FIG. 2 shows an example of the configuration of the entire communication system using the broadcast control device according to the present embodiment.

In FIG. 2, wired broadcast control devices 1 to 3 are connected to a network 1 via a hub, and wireless broadcast control devices 4 to 6 are connected via a wireless base station. . Network 1 is also connected to network 2. The network 3 is constituted by a wireless broadcast control device, and is connected to the network 2. The network 4 is composed of wired devices and is connected to the network 2. Each network is connected by a router.

FIG. 3 shows an example of a logical tree structure when the broadcast control device according to the present embodiment forms a broadcast group.

The device 1, which is the root of the tree, is the device 2,
3 and 9 are managed. The device 2 manages the devices 10, 11, and 12, the device 3 manages the devices 4, 5, and 6, and the device 9 manages the devices 7 and 8. A device that manages its own device is called a parent device, and a device that is managed by its own device is called a child device.

For example, the parent device of the device 3 is the device 1,
The child devices of the device 3 are the devices 4, 5, and 6. Since device 1 is the root of the tree, there is no parent device.

This tree structure is logical and is formed by negotiation between devices. It does not necessarily represent a configuration with physical connections. But,
Collectively managing the devices physically connected to the same network may utilize the multicast function of the network, thereby increasing communication efficiency.

For example, the device 4 managed by the device 3
Since devices 5 and 6 are connected to the same network, assuming that this network is a wireless LAN compatible with Ethernet, device 3 uses the multicast function of Ethernet to transfer packets to devices 4, 5, and 6; The number of transmission packets can be reduced as compared with the case where packets are separately transferred to each device using unicast.

FIG. 4 shows the management table 2 in FIG. 1. The identifier of the parent device managing the own device is stored in the parent device identifier field, and the identifier of the device belonging to the broadcast group is stored in the device identifier field. , The identifier of the device managed by each device is stored in the child device identifier field, and among the sequence numbers of the data received from each device, the continuous and maximum sequence number is stored in the received sequence number field. . FIG. 4 shows the management table 2 of the device 3 as an example, but other devices also have the same table 2.

When the own device manages another device, it has a table 2 as shown in FIG. 5 in addition to FIG.

FIG. 5 also shows the management table 2 of the device 3, which stores the delivery confirmation numbers received from the devices 4, 5, and 6.

Here, the relationship between the sequence number, the reception sequence number, the delivery confirmation number, and the reception confirmation number will be described.

A sequence number is added to a plurality of data packets and transmitted to another device in order. In this case, the sequence numbers are added to a plurality of data packets and transmitted while ascending in the order of 1, 2, 3, 4,.... For example, the device 6 in FIG.
After transmitting the data packets, the final sequence number becomes 300.

In the device 4 receiving the 300 data packets, the maximum sequence number (= 30)
0) is the reception sequence number (= 300) described above.
Becomes

Then, the device 4 sends back the reception sequence number (= 300) as an acknowledgment number (= 300) to the device 3 as its parent device as an ACK packet.

The device 3 compares the acknowledgment number (= 300) returned from the device 4 as an ACK packet with the currently stored reception acknowledgment number in FIG. Then, if the currently stored reception acknowledgment number is a number smaller than 300, devices 4, 5 (device 6 is a data packet sender which is a child device for updating the reception acknowledgment number to 300 are excluded. ), The ACK packet is transmitted to the device 1 which is the parent device.

(Operation when receiving data transmission request) FIG. 6
5 is a flowchart illustrating an operation when a data transmission request is received from an upper layer.

When the device 1, which is the root of the tree, intends to transmit a data packet in accordance with a request from an upper layer, first, the received data is shaped into a packet.

Specifically, data is divided according to the maximum packet length determined by the network used,
A header is added to each of the divided data to form a packet.

Then, sequence numbers for uniquely identifying each packet are assigned in ascending order, and stored in the sequence number field in the header. Device 1 is device 2,
The packet is transmitted to 3 and 9. And device 1
Holds the data packet in the transmission buffer in the data transfer control unit 1 until the ACK packet is received from the device 2, 3, or 9.

When a device other than the root of the tree attempts to transmit a data packet in accordance with a request from an upper layer, the data is shaped into a packet, a sequence number is stored, and the packet is transmitted to the root device 1. I do. The processing performed by the device 1 having received the packet is the same as the above processing.

(Operation when Data Packet is Received) The processing when the data packet transmitted as described above is received will be described. FIG. 7 is a flowchart showing an operation when a data packet is received.

The device that has received the data packet determines whether the received packet is the first one.

If it is not the first time, the packet has either already been in the receive buffer or has been passed to the upper layer.

If the packet has been received for the first time, the packet is stored in the reception buffer, and it is checked whether there is any data loss or error.

If there is a missing or an error, a NAK packet is transmitted to the parent device to retransmit the data. N
The AK packet stores the sequence number of the data requested to be retransmitted.

If there is no loss or error, the sequence number is confirmed to be transmittable, and the data packet is transmitted to the device managed by the own device. The source table entry is searched from the management table 2, and the reception sequence number is updated. Then, the ACK packet transmission timer is set. The ACK packet stores, as a delivery confirmation number, a continuous and maximum sequence number among the received data packets.

(Operation at the time of NAK packet reception) FIG.
9 is a flowchart showing an operation at the time of receiving a NAK packet.

The device receiving the NAK packet checks whether or not the data packet requested to be retransmitted is in the reception buffer. If so, the data packet is transmitted to the NAK transmission source device. If not, a NAK packet is transmitted to the parent device to request data retransmission.

(Operation at Receiving ACK Packet)
FIG. 9 shows the operation when the CK packet is received.

The device that has received the ACK packet searches the management table 2 for an entry of the transmission source device, and compares the reception acknowledgment number in Table 2 with the ACK packet delivery acknowledgment number. If the packet acknowledgment number is smaller or equal, the process ends. Otherwise, the value of the management table 2 is updated. If the acknowledgment numbers of all the devices under management have been updated, an ACK packet storing the smallest value among the acknowledgment numbers is transmitted to the parent device. Then, if there is a data packet having a sequence number equal to or less than the transmittable sequence number, the data packet is transmitted to the device managing the data packet.

(Operation when ACK Packet Transmission Timer Times Out) FIG. 10 is a flowchart showing an operation when the ACK packet transmission timer times out. The processing when the ACK packet transmission timer times out differs depending on whether or not there is a device managed by the own device.

First, the processing when there is a device managed by the own device will be described.

The management table 2 stores, for each managed device, a reception acknowledgment number indicating from which device each device has received data and to what extent (see FIG. 4). If the reception acknowledgment number indicating how far data has been received from a certain device has been updated for all managed devices, an ACK packet is transmitted to the parent device. Otherwise, the process ends.

Next, a process when there is no device managed by the own device will be described.

The management table 2 stores a reception sequence number indicating from which device the data has been received by the own device and to what extent (see FIG. 4). If at least one reception sequence number has been updated, ACK is sent to the parent device.
Send a packet.

(Operation when Difference Between Number of Devices Managed by Own Device and Number of Devices Managed by Other Devices Exceeds Predetermined Number) FIG. 11 shows devices managed by the own device. 10 is a flowchart illustrating an operation when a difference between the number and the number of devices managed by devices having the same logical distance from the root in the tree structure to the own device exceeds a certain number.

An arbitrary device (device A) is selected from the devices managed by the own device.

Next, among the devices having the same logical distance from the root to the own device, a device which manages less devices than the number of devices managed by the own device is found, and the management information of the device A is addressed to the device. Send The contents of the management information are shown in FIG.
Is a list of pairs of the device identifier and the reception acknowledgment number as shown in FIG.

As described above, when the number of devices managed by the own device is larger than the number of devices managed by another device and exceeds the allowable range, the management of the own device is performed by leaving the management to the other device. The load can be reduced, and the possibility of a bottleneck due to insufficient processing capacity can be reduced. In addition to the comparison with the number of devices managed by another device, the device managed by the own device can be managed by another device based on the upper limit determined from the processing capacity of the own device. .

(Operation at the Time of Receiving Management Information Packet) On the other hand, FIG. 12 is a flowchart showing the operation at the time of receiving the management information packet.

Receiving the management information packet means that the management of a certain device has been requested.
First, it is determined whether or not there is a capability to manage a new device. If it is determined that there is no capability, a rejection packet is transmitted to the transmission source of the management information packet, and the process ends. When it is determined that the device has the capability, an entry is created in the management table 2 based on the device information carried by the management information packet, and the information is registered. Then, the reception packet is transmitted to the transmission source of the management information packet. If necessary data is transmitted to the newly added device, it is transmitted. If not, a NAK packet of the data is transmitted to the parent device.

FIG. 13 shows the format of the ACK packet.

The ACK packet stores, besides the destination address and the source address, the minimum value for each device among the delivery confirmation numbers received from the devices managed by the own device.

Second Embodiment FIG. 14 shows an example of the configuration of a broadcast control apparatus according to a second embodiment of the present invention.

The operation of each section is almost the same as that of the first embodiment, except for the operation when a data packet is received.
The reference numerals of the devices corresponding to the first embodiment are the same as those of the first embodiment.
It is assumed that the reference numerals of the apparatus of the embodiment are in the 100's.

FIG. 15 is a flowchart showing an operation when a data packet is received in the second embodiment.

The device that has received the data packet determines whether the received packet is the first one.

If it is not the first time, the packet has either already been in the reception buffer or has been passed to the upper layer. Refers to the management table 2 and checks whether or not the acknowledgment has already been performed from all the devices managed by the own device for the retransmission data packet, and if the acknowledgment has been performed, transmits an ACK packet to the parent device. I do.

If the packet is received for the first time, the packet is stored in the reception buffer, and it is checked whether data is missing or error.

If there is a missing or an error, a NAK packet is transmitted to the parent device to retransmit the data. N
The AK packet stores the sequence number of the data requested to be retransmitted.

If there is no loss or error, the sequence number is confirmed to be transmittable, and the data packet is transmitted to the device managed by the own device. The source table entry is searched from the management table 2, and the reception sequence number is updated. Then, the ACK packet transmission timer is set. The ACK packet stores, as a delivery confirmation number, a continuous and maximum sequence number among the received data packets.

Third Embodiment FIG. 16 shows an example of the configuration of a broadcast control device according to a third embodiment of the present invention.

The operation of each unit is almost the same as that of the first embodiment, except that a new communication possibility determination unit 207 is provided to monitor the state of the communication path between the managed device and the own device. When it is determined that the continuation of the communication is impossible, a process of removing the device from the tree structure is performed. The reference numerals of the devices corresponding to those of the first embodiment are the same as those of the first embodiment except that the reference numerals are in the 200s.

The detailed operation will be described below.

The communication possibility determining unit 207 monitors the state of the communication path between the own apparatus and the managed apparatus, and the state of the communication path is bad for a certain period of time, and a transmission error occurs at a certain ratio or more. If the ACK packet does not arrive even after repeating the retransmission of the data packet more than a certain number of times, it is considered that communication with the device has become impossible. Then, this is notified to the tree structure control unit 6. Tree structure control unit 6
Receives the notification that communication with the device has become impossible, and disconnects the device from the tree structure. at the time,
If the reception acknowledgment numbers from all the remaining devices managed by the own device have been updated, the ACK packet is transmitted to the parent device.

FIG. 17 is a flowchart showing the operation when it is determined that communication with the device managed by the own device has become impossible.

The entry of the corresponding device is searched from the management table 2 and deleted. The reception acknowledgment numbers of the remaining devices are checked, and if all the reception acknowledgment numbers of a certain device have been updated, an ACK packet is transmitted to the parent device.

In the first to third embodiments, a program capable of executing the contents of each flowchart is stored in the FD or the CD-ROM 12. The above contents may be realized by installing the contents in the portable information communication device 10 having a personal computer function as shown in FIG.

[0092]

According to the communication device of the first aspect, it is possible to reliably confirm the delivery of information based on the management information, and to prevent erroneous transmission of information such as data. Therefore, information can be reliably transmitted from the parent device to the child device.

According to the communication device of the second aspect, when it is not possible to confirm the delivery of the information based on the management information, the retransmission information is sent, and the delivery confirmation is performed based on the retransmission information. Information can be transmitted reliably.

According to the communication device of the third aspect, the tree structure can be flexibly changed so that the load of each device is biased due to a change in the number of groups and, for example, a certain device does not become a bottleneck, and the efficiency is improved. Data transfer and delivery confirmation.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a broadcast control device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration example of an entire communication system using a broadcast control device according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating an example of a logical tree structure when the broadcast control device according to the embodiment of the present invention forms a broadcast group.

FIG. 4 is a diagram showing an example of a management table 2 in FIG.

FIG. 5 is a diagram showing an example of a management table 2 in FIG.

FIG. 6 is a flowchart illustrating an operation when a data transmission request is received from an upper layer.

FIG. 7 is a flowchart showing an operation when a data packet is received.

FIG. 8 is a flowchart showing an operation at the time of receiving a NAK packet.

FIG. 9 is a flowchart showing an operation when an ACK packet is received.

FIG. 10 is a flowchart illustrating an operation when an ACK packet transmission timer times out.

FIG. 11 illustrates an operation performed when a difference between the number of devices managed by the own device and the number of devices managed by devices having the same logical distance from the root in the tree structure to the own device exceeds a certain number. It is a flowchart which shows.

FIG. 12 is a flowchart illustrating an operation when a management information packet is received.

FIG. 13 is a diagram showing a format of an ACK packet.

FIG. 14 is a diagram illustrating a configuration example of a broadcast control device according to a second embodiment of the present invention.

FIG. 15 is a flowchart illustrating an operation when a data packet is received in the second embodiment.

FIG. 16 is a diagram illustrating a configuration example of a broadcast control device according to a third embodiment of the present invention.

FIG. 17 is a flowchart illustrating an operation when it is determined that communication with a device managed by the own device has become impossible.

FIG. 18 is a perspective view of a portable information communication device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Data transfer control part 2 Management table 3 Network interface part 4 Delivery confirmation control part 5 Retransmission request control part 6 Tree structure control part

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kazuaki Iwamura 1-30, Oyodonaka, Kita-ku, Osaka-shi, Osaka Umeda Sky Building Tower West Toshiba Kansai Branch Office (72) Inventor Shogo Yamaguchi Osaka 1-30 Oyodonaka, Kita-ku, Osaka Umeda Sky Building Tower West Toshiba Kansai Branch

Claims (9)

[Claims] 1. A plurality of communication devices in which one or more child devices are provided so as to be able to communicate with each other in one parent device, an identifier of a child device managed by the own device, and a delivery confirmation received from the child device. Management information storage means for storing management information including at least information; a parent device identifier storage means for storing an identifier of a parent device managing the own device; and all children stored in the management information storage means. Equipment and
Or, an information communication unit that transmits and receives information to and from the parent device stored in the parent device identifier storage unit, and a child device that transmits information by the information communication unit,
Acknowledgment means for comparing acknowledgment information indicating that the information has been received and the management information to confirm acknowledgment of the transmitted information, and when the acknowledgment means has confirmed acknowledgment of the transmitted information. And a transmission confirmation transmitting means for transmitting transmission confirmation information to the parent device. 2. An information retransmission for retransmitting the transmitted information as retransmission information when the acknowledgment means cannot perform acknowledgment or when retransmission request information indicating that the information has not been correctly received is received. Means, the information communication means retransmits the retransmission information from the parent device to all the child devices stored by the management information storage means, the transmission confirmation transmission means, The communication device according to claim 1, wherein when a delivery confirmation is made from said child device by said delivery confirmation means, delivery confirmation information is transmitted to said parent device. 3. When the number of child devices stored by the management information storage means exceeds a reference, management information of a predetermined number of child devices is removed from the management information storage means, and the removed management information is replaced by another device. 2. The communication apparatus according to claim 1, further comprising a management information transmitting unit that transmits the management information to another device, wherein the management information storage unit stores management information received from another device. 4. A communication method in a plurality of communication devices in which one or more child devices are provided so as to be able to communicate with each other in one parent device, wherein an identifier of the child device managed by the own device and the child device are provided. A management information storing step of storing management information including at least acknowledgment information received from the storage device; a parent device identifier storing step of storing an identifier of a parent device managing the own device; And all the child devices, or, the information communication step of transmitting and receiving information to and from the parent device stored in the parent device identifier storage step, from the child device that has transmitted information in the information communication step, A acknowledgment step of comparing acknowledgment information indicating reception and the management information to confirm acknowledgment of the transmitted information; When you are acknowledgment of the transmitted information at step communication method characterized by comprising the acknowledgment transmission step of transmitting the acknowledgment information to the parent device. 5. An information retransmission for retransmitting the transmitted information as retransmission information when the acknowledgment cannot be performed in the acknowledgment step or when retransmission request information indicating that the information was not correctly received is received. In the information communication step, the retransmission information from the parent device is retransmitted to all the child devices stored in the management information storage step, and in the delivery confirmation transmission step, all of the retransmission information The communication method according to claim 4, wherein when a delivery confirmation is made from said child device in said delivery confirmation step, delivery confirmation information is transmitted to said parent device. 6. When the number of child devices stored in the management information storage step exceeds a reference, management information of a predetermined number of child devices is excluded from the management information storage step, and the removed management information is replaced with another device. The communication method according to claim 4, further comprising a management information transmitting step of transmitting the management information received from another device in the management information storing step. 7. A recording medium recording a program of a communication method used in a plurality of communication devices in which one or more child devices are provided in one parent device so as to be able to communicate with each other. A management information storage function of storing management information including at least the acknowledgment information received from the child device, and a parent device identifier storage function of storing the identifier of the parent device managing the own device. All child devices stored in the management information storage function,
Or, an information communication function of transmitting and receiving information to and from the parent device stored in the parent device identifier storage function, and a delivery confirmation information indicating that the information has been received from the child device that transmitted the information by the information communication function. And a delivery confirmation function of comparing the management information with the management information to confirm delivery of the transmitted information; and transmitting delivery confirmation information to the parent device when the delivery confirmation function is able to confirm delivery of the transmitted information. A recording medium for a communication method program, characterized by recording a delivery confirmation transmission function. 8. An information retransmission for retransmitting the transmitted information as retransmission information when a transmission confirmation cannot be performed by the transmission confirmation function or when retransmission request information indicating that information was not correctly received is received. The information communication function retransmits the retransmission information from the parent device to all the child devices stored by the management information storage function, and the delivery confirmation transmission function relates to the retransmission information. 8. The recording medium according to claim 7, wherein the transmission confirmation information is transmitted to the parent device when the transmission confirmation function is performed from all the child devices by the transmission confirmation function. 9. When the number of child devices stored by the management information storage function exceeds a reference, management information of a predetermined number of child devices is removed from the management information storage function, and the removed management information is replaced by another device. 8. The recording medium according to claim 7, wherein a management information transmission function to be transmitted to the communication device is recorded, and the management information storage function stores management information received from another device.