JP4013393B2 - Wireless communication method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
INDUSTRIAL APPLICABILITY The present invention makes it possible to operate instantaneously when each electric radio base station is turned on in a wireless network in which information can be exchanged between various electric devices such as home appliances and computers by optical radio. More specifically, the present invention relates to a wireless communication method and apparatus for automatically grasping the connection state of each electrical device in order to realize plug and play. More specifically, a plurality of wireless terminals are connected to a wireless base station via a wireless line, for example, IEEE1394. The present invention relates to a wireless communication method and apparatus conforming to the IEEE 1394 standard for identifying a connection state of a tree structure of a plurality of wireless terminals in a wireless network configured to achieve the standard.
[0002]
[Prior art]
For example, in a communication method conforming to IEEE 1394 (hereinafter abbreviated as IEEE 1394 communication method), there is no concept of a virtual port, and tree identification performed after a bus reset to determine a parent-child relationship between devices connected to a bus A method is defined in which an identification signal is transmitted from a device in which one device is connected to a real port during operation. In addition, when only one device is connected to another port, the device that has received the identification signal transmits the identification signal to the device. By repeating such a procedure, the terminal that cannot transmit the identification signal at the end becomes the apex (parent) of the tree.
[0003]
That is, in the IEEE 1394 communication system, after the bus is reset, a tree identification operation is performed to determine the parent-child relationship between devices connected to the bus. This tree identification procedure conforms to the conditions defined by the IEEE 1394 standard. A connection confirmation identification signal (parent notify) is transmitted from the terminal to the other terminal connected to the terminal. Subsequently, a reply identification signal (child notify) indicating that the previous identification signal has been received is returned from another terminal that has received this identification signal. A tree is constructed by performing such an operation between all terminals connected to the bus.
[0004]
This will be described more specifically with reference to the drawings. As shown in FIG. 3, a tree identification operation for determining a parent-child relationship between devices connected to a bus after a bus reset in a plurality of devices connected by wires will be described. A terminal that can transmit an identification signal after a bus reset is a terminal in which only one other device is connected to the IEEE 1394 port.
[0005]
Therefore, in FIG. 3, the terminal 11 transmits an identification signal to the terminal 12, the terminal 13 to the terminal 12, and the terminal 15 to the terminal 14. Next, each terminal that receives the identification signal can transmit the identification signal to the terminal when only one terminal is connected to the terminal other than the terminal that transmitted the identification signal to its IEEE 1394 port. The transmitted identification signal is received by the other party, and the tree identification is completed. Upon completion of this processing procedure, tree identification of all devices connected to the IEEE 1394 bus is completed, and the connection state of the tree structure with the terminal 12 as the apex is found as shown in FIG.
[0006]
[Problems to be solved by the invention]
When the above-described tree identification procedure is applied to a one-to-one wireless system, there is no problem because a terminal that receives an identification signal transmitted from a specific wireless terminal is only one other wireless terminal. However, in a 1-to-n system that can simultaneously transmit signals to a plurality of terminals and receive signals simultaneously from a plurality of terminals such as a radio base station, the identification signal transmitted from the radio base station is transmitted by the plurality of terminals. A situation in which an identification signal indicating that the identification signal has been received at the same time is returned from a plurality of terminals that have received the identification signal at the same time, and the radio base station cannot receive the identification signal that is simultaneously returned. There is a problem of falling into.
[0007]
Specifically, the tree identification operation in the wireless system shown in FIG. 5 will be described. Considering a terminal capable of transmitting an identification signal in accordance with the above-described identification signal transmission condition, that is, a terminal that can transmit an identification signal after a bus reset is a terminal in which only one other device is connected to the IEEE 1394 port. In the example of FIG. 5, all the terminals are connected to the IEEE 1394 port, so that identification signals can be transmitted from all the terminals. When the radio base station 35 receives the identification signal transmitted from the terminal 31, it tries to relay this identification signal to the terminals 32, 33, and 34. This identification signal is simultaneously received by the terminals 32, 33, and 34, and a plurality of terminals that have received this identification signal simultaneously return an identification signal indicating that the identification signal has been received to the radio base station 35, and the radio base station 35 cannot receive the identification signal.
[0008]
Further, the terminals 32, 33, and 34 simultaneously transmit identification signals to the radio base station 35, but the identification signals from the terminals 32, 33, and 34 are simultaneously transmitted to the radio base station 35. The radio base station 35 cannot receive this identification signal. Therefore, the terminals 32, 33, and 34 repeat the operation of transmitting identification signals to the radio base station all at once in a similar manner after a predetermined time has elapsed. Such a state is repeated forever, and tree identification is performed. There is a problem that the operation cannot be terminated.
[0009]
The present invention has been made in view of the above, and the object of the present invention is the next time even when the connection confirmation identification signal cannot be properly received because the connection confirmation identification signals are simultaneously transmitted from a plurality of wireless terminals. An object of the present invention is to provide an IEEE 1394 wireless communication method and apparatus capable of appropriately performing a tree identification operation by changing the transmission timing thereafter.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention according to claim 1 is configured such that a plurality of wireless terminals are connected to a wireless base station via a wireless line to achieve a predetermined standard, for example, the IEEE 1394 standard. A wireless communication method for identifying a connection state of a tree structure of a plurality of wireless terminals in a wireless network, wherein, among the plurality of wireless terminals, one other device including a wireless base station at its own predetermined port Each of the wireless terminals connected only transmits a connection confirmation identification signal to the other device, and when the other device receives the connection confirmation identification signal, Each wireless terminal that has sent back a reply identification signal to each wireless terminal that is a transmission destination and has transmitted the connection confirmation identification signal sends the reply identification signal from the other device within a predetermined time. If not received, again respectively at its own random time interval, to increase the transmission of the connection confirmation identification signal to the other devices.
[0011]
In the first aspect of the present invention, each wireless terminal transmits a connection confirmation identification signal to another device, and when the other device receives the connection confirmation identification signal, the wireless terminal is a transmission destination thereof. If each wireless terminal that has sent back a reply identification signal to each wireless terminal and has transmitted the connection confirmation identification signal does not receive the reply identification signal from another device within a predetermined time, each wireless terminal has its own random Since the connection confirmation identification signal is transmitted to another device again at a time interval, each wireless terminal is unique even if it cannot receive the reply identification signal because multiple wireless terminals have transmitted the connection confirmation identification signal at the same time. Retransmission is performed after a random time interval, and the retransmission time is random at each wireless terminal, and is not retransmitted at the same time. This It can be, it is possible to grasp the connection status of the tree structure.
[0012]
According to a second aspect of the present invention, there is provided a wireless network in which a plurality of wireless terminals are connected to a wireless base station via a wireless line and configured to achieve a predetermined standard, for example, the IEEE 1394 standard. A wireless communication device for identifying a connection state of a tree structure of wireless terminals, wherein each of the plurality of wireless terminals has only one other device including a wireless base station connected to its own port A transmission means for transmitting a connection confirmation identification signal to the other device, and a reply identification signal from the other device in response to the transmitted connection confirmation identification signal within a predetermined time, Timing control means for controlling the transmission means so as to re-transmit the connection confirmation identification signal to the other device at a random time interval unique to the wireless terminal; And it is required to.
[0013]
In the present invention according to claim 2, each wireless terminal transmits a connection confirmation identification signal to another device, and when the other device receives the connection confirmation identification signal, the wireless terminal is a transmission destination thereof. If each wireless terminal that has sent back a reply identification signal to each wireless terminal and has transmitted the connection confirmation identification signal does not receive the reply identification signal from another device within a predetermined time, each wireless terminal has its own random Since the connection confirmation identification signal is transmitted to another device again at a time interval, each wireless terminal is unique even if it cannot receive the reply identification signal because multiple wireless terminals have transmitted the connection confirmation identification signal at the same time. Retransmission is performed after a random time interval, and the retransmission time is random at each wireless terminal, and is not retransmitted at the same time. This It can be, it is possible to grasp the connection status of the tree structure.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a device configuration for performing a tree identification operation in the IEEE 1394 wireless communication method according to an embodiment of the present invention. In the figure, a terminal 41 is connected to a wireless base station 45, and a plurality of wireless terminals 42, 43, and 44 are connected via a wireless line.
[0015]
The wireless base station 45 transmits information to one or more IEEE 1394 real ports 51 to which the terminal 41 is connected, a virtual port management unit 54 that manages a plurality of IEEE 1394 virtual ports, the wireless terminal 42-44, or information to the wireless terminal 42-44. A wireless information transmission / reception unit 55 for wireless transmission / reception, an identification signal detection unit 52 for detecting an identification signal transmitted from the wireless terminals 42, 43, and 44, and when the identification signal is detected, the identification signal reception signal is wirelessly transmitted. It comprises an identification signal reception signal generator 53 that returns to the terminals 42, 43, 44.
[0016]
Each of the plurality of wireless terminals 42, 43, 44 transmits an identification signal to the wireless base station 45 and the wireless information transmitting / receiving unit 56 for wirelessly transmitting / receiving information to / from the wireless base station 45. An identification signal generation unit 57, an identification signal reception signal detection unit 58 that detects an identification signal reception signal transmitted from the radio base station, and a timing generation unit 59 that informs the identification signal generation unit 57 of the timing of generation of the identification signal. Has been. In FIG. 1, only the configuration of the wireless terminal 42 is shown in detail, but the other wireless base stations 43 and 44 have the same configuration.
[0017]
Next, a tree identification operation in the embodiment configured as described above will be described. First, as a precondition, it is assumed that the virtual port management unit 54 in the radio base station 45 virtually manages IEEE 1394 ports that are equal to or more than the number of radio terminals. Further, the virtual port management unit 54 assumes that wireless terminals are connected to the virtual port for a predetermined period after the reset, and if the period has passed, the number of wireless terminals that actually received the identification signal. Only manage and discard the rest.
[0018]
First, in accordance with the above-described conditions, that is, a terminal that can send a connection confirmation identification signal (parent notify) after reset is a terminal in which only one other device is connected to the IEEE 1394 port. The terminals that can transmit the identification signal are the terminal 41 and the wireless terminals 42, 43, and 44.
[0019]
The connection confirmation identification signal transmitted from the terminal 41 is received by the radio base station 45 without any problem. That is, an identification signal (parent notify) that is a connection confirmation identification signal transmitted from the terminal 41 is received by the radio information transmitting / receiving unit 55 of the radio base station 45 and detected by the identification signal detecting unit 52. When the identification signal detection unit 52 detects the connection confirmation identification signal from the terminal 41, the radio base station 45 generates an identification signal reception signal that is a reply identification number (child notify) from the identification signal reception signal generation unit 53. The identification signal receipt signal is returned to the terminal 41. Thereby, the tree identification operation is completed between the terminal 41 and the radio base station 45.
[0020]
Next, the operation of the wireless terminal 42 will be described. After the reset, the wireless terminal 42 transmits the connection confirmation identification signal from the identification signal generating unit 57 to the wireless base station 45 via the wireless information transmitting / receiving unit 56. At this time, assuming that the connection confirmation identification signal generated from the identification signal generator 57 of the other wireless terminal 43 or 44 is also transmitted to the wireless base station 45 at the same time, the wireless base station 45 is transmitted from the wireless terminals 42, 43, 44, respectively. Since the transmitted connection confirmation identification signal cannot be accurately received, the connection confirmation identification signal transmitted from each of the wireless terminals 42, 43, 44 is ignored by the wireless base station 45.
[0021]
When the wireless terminal 42 does not receive the identification signal receipt signal from the wireless base station 45 within a predetermined time after transmitting the connection confirmation identification signal as described above, the timing generator 59 operates to generate the timing. The unit 59 monitors the lapse of a certain random time, and supplies a retransmission command of the connection confirmation identification signal to the identification signal generation unit 57 after the lapse of this time. Upon receipt of this retransmission instruction, the identification signal generator 57 transmits the connection confirmation identification signal to the radio base station 45 again via the radio information transmitter / receiver 56. The radio base station 45 receives the retransmitted identification signal for connection confirmation by the radio information transmitter / receiver 55 and transfers it to the identification signal detector 52.
[0022]
When the identification signal detection unit 52 detects the connection confirmation identification signal, the identification signal detection unit 52 notifies the virtual port management unit 54 and the identification signal reception signal generation unit 53 that the connection confirmation identification signal has been received. Upon receipt of this notification, the identification signal reception signal generation unit 53 returns an identification signal reception signal to the wireless terminal 42 via the wireless information transmission / reception unit 55.
[0023]
At this time, the other wireless terminals 43 and 44 also receive the identification signal reception signal, but the condition that the identification signal for connection confirmation is not transmitted or the predetermined time is exceeded after the identification signal for connection confirmation is transmitted. This identification signal reception signal is ignored based on the condition that
[0024]
When the wireless terminal 42 receives the identification signal reception signal returned from the wireless base station 45 by the identification signal reception signal detection unit 58 via the wireless information transmission / reception unit 56 and detects the identification signal reception signal, the wireless terminal 42 detects the identification signal reception signal. The unit 58 prohibits the timing generation unit 59 from generating an identification signal transmission command. Thereby, the tree identification operation after reset in the wireless terminal 42 is completed.
[0025]
The other wireless terminals 43 and 44 perform the tree identification operation by the same processing procedure. The virtual port management unit 54 of the wireless base station 45 recognizes that the three wireless terminals 42, 43, and 44 are connected by the above-described tree identification operation, and discards the remaining virtual ports after a certain period of time. To do. The tree structure shown in FIG. 2 is completed by the tree identification operation described above.
[0026]
【The invention's effect】
As described above, according to the present invention, when each wireless terminal that has transmitted the connection confirmation identification signal does not receive the reply identification signal from another device within a predetermined time, each wireless terminal has its own random time interval. In this case, the connection confirmation identification signal is transmitted to another device again, so that even if a plurality of wireless terminals transmit the connection confirmation identification signal at the same time and thus cannot receive the reply identification signal, each wireless terminal has its own random number. Retransmission is performed after a time interval, and this retransmission time is random at each wireless terminal and is not retransmitted at the same time. It is possible to grasp the connection state of the tree structure.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an apparatus configuration for performing a tree identification operation in an IEEE 1394 wireless communication method according to an embodiment of the present invention.
FIG. 2 is a diagram showing a tree structure created by the tree identification operation of the embodiment shown in FIG. 1;
FIG. 3 is a diagram showing a configuration of a conventional system for explaining a tree identification operation;
4 is a diagram showing a connection state of a tree structure that has been found as a result of a tree identification operation in the system shown in FIG. 3;
FIG. 5 is a diagram illustrating a configuration example of a wireless system for explaining a conventional tree identification operation in the wireless system.
[Explanation of symbols]
41 Terminal 42-44 Wireless terminal 51 IEEE 1394 real port 52 Identification signal detection unit 53 Identification signal reception signal generation unit 54 Virtual port management unit 55, 56 Wireless information transmission / reception unit 57 Identification signal generation unit 58 Identification signal reception signal detection unit 59 Timing generation Part

Claims (2)

A wireless communication method for identifying a connection state of a tree structure of a plurality of wireless terminals in a wireless network configured to connect a plurality of wireless terminals to a wireless base station via a wireless line and achieve a predetermined standard Because
Among each of the plurality of wireless terminals, each of the wireless terminals in which only one other device including a wireless base station is connected to its own predetermined port sends a connection confirmation identification signal to the other device. Send
When the other device receives the connection confirmation identification signal, it returns a reply identification signal to each of the wireless terminals to which the connection confirmation identification signal is transmitted,
If each wireless terminal that has transmitted the connection confirmation identification signal does not receive the reply identification signal from the other device within a predetermined time, the wireless connection terminal again repeats the connection confirmation identification at its own random time interval. A wireless communication method comprising transmitting a signal to the other device. A wireless communication apparatus for identifying a connection state of a tree structure of a plurality of wireless terminals in a wireless network configured to connect a plurality of wireless terminals to a wireless base station via a wireless line and achieve a predetermined standard Because
Each of the plurality of wireless terminals transmits a connection confirmation identification signal to the other device when only one other device including a wireless base station is connected to its own predetermined port. Means,
When a reply identification signal is not received from the other device within a predetermined time with respect to the transmitted connection confirmation identification signal, the wireless communication terminal transmits the connection confirmation identification signal with a unique random time interval. A wireless communication apparatus comprising: a timing control unit that controls the transmission unit so as to transmit again to another device.

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