JP3699083B2 - Wireless communication method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wireless communication method and a wireless communication terminal having a function of implementing the wireless communication method, and particularly to a wireless LAN system and a home network system that share and use a wireless band among a plurality of terminals. .
[0002]
[Prior art]
Currently, local area networks (LANs) are commonplace in offices and are becoming popular in small stores and homes. In addition, as a network configuration method, a method using radio, IrDA, or the like from a conventional coaxial cable or twisted pair wire has also appeared.
[0003]
As an example, a wireless LAN media access control (MAC) method using 2.4 GHz band radio defined by IEEE802.11 and an infrared communication method link access protocol method using IrDA will be described.
[0004]
FIG. 10A is a diagram illustrating a protocol of the MAC layer defined by IEEE 802.11. This protocol is called CSMA / CA + ACK, and a procedure for performing radio-specific control has been added to the Ethernet (registered trademark) MAC CSMA / CA, which is a wired LAN standard defined in IEEE 802.3. It is a thing.
[0005]
CSMA / CA defined in IEEE 802.3 is a method for monitoring the state of a signal on a shared physical medium and transmitting data 101 if no one is using it. As a result of monitoring the signal state, if a signal exists on the physical medium, the monitoring state is entered again after waiting for a certain time. CSMA / CA + ACK specified in IEEE802.11 uses a transmission request RTS102, a corresponding CTS103, and a data reception acknowledgment ACK104 to solve radio-specific problems. In this way, reliable data transmission can be achieved.
[0006]
FIG. 10B is a diagram showing an ASK link access layer protocol used for communication using IrDA. Similar to FIG. 10A, a transmission request / response and data ACK are required for data transmission.
[0007]
When communication is performed using such wireless or IrDA as a medium, communication capacity and communication speed are limited as compared with wired communication, so efficient communication control must be performed. On the other hand, when wireless or IrDA is used, there is no cable connection compared to wired communication, and communication between a plurality of terminals can be facilitated. Therefore, communication control is performed so that a plurality of terminals can be used simultaneously.
[0008]
However, in this communication control, when a terminal performs communication, it is a procedure based on handshaking (request and response) with a partner terminal or a communication master in the network. As a result, the throughput for the terminal to perform communication is reduced.
[0009]
In addition, when managing a network with a master, the master is always required on the network, and if the protocol is complicated, such as switching the master and installing a submaster, or if the master is fixed, participation in and withdrawal from the network is free I could not do it.
[0010]
In addition, in order to share the wireless band among multiple terminals, a method of effectively using the band by using frequency spreading has been proposed, but the wireless control method is complicated and requires a huge amount of hardware. It was. In addition, since the data traffic of devices connected to the network is diverse and there are various communication methods, the conventional communication method that assigns frequencies and time slots in a fixed manner has the disadvantage that the network usage efficiency is poor. was there.
[0011]
[Patent Document 1]
Japanese Patent Laid-Open No. 6-77866 [0012]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and is intended to perform efficient communication control when performing communication using wireless or IrDA as a medium. Further, a plurality of terminals can be used simultaneously. The purpose is to perform such communication control.
[0013]
[Means for Solving the Problems]
To achieve the above object, the present invention is, when communicating between multiple terminals, when sharing the radio band to be used between the plurality of terminals, each terminal communicates, in turn, to the network A wireless communication method for ensuring synchronization of the entire network by grasping the participating terminals and sending out a synchronization word provided with an address map field for managing the sending order of the synchronization words. A step of monitoring whether a synchronization word is transmitted from a terminal other than the first terminal of the plurality of terminals by a first terminal of the plurality of terminals, and a step other than the first terminal by the first terminal When the synchronization word is not transmitted from another terminal, an address indicating that the first terminal has joined the network is acquired in an address map field provided in the synchronization word. And a step of sending a synchronization word provided with an address map field in which an address indicating that the first terminal has participated is provided to another terminal other than the first terminal by the first terminal. And a step of monitoring whether a synchronization word is transmitted from a terminal other than the second terminal by a second terminal of the plurality of terminals, and a step other than the second terminal by a second terminal The synchronization word is sent from another terminal, and after receiving the synchronization word from the other terminal other than the second terminal by the second terminal, A step of acquiring an address indicating that the second terminal has joined the network in an address map field provided in the synchronization word; and an address indicating that the second terminal has joined by the two terminals. The synchronization word obtained address map field is provided comprising the steps of transmitting to another terminal other than the second terminal,
A step of monitoring whether a synchronization word is transmitted from another terminal other than the third terminal by a third terminal in the plurality of terminals; and a step other than the third terminal by a third terminal The synchronization word is transmitted from the terminal of the terminal, and the synchronization word is received by the third terminal after receiving the synchronization word from a terminal other than the third terminal by the third terminal. A step of acquiring an address indicating that the third terminal has joined the network in an address map field provided therein, and an address indicating that the third terminal has been acquired by the third terminal. And sending a synchronization word provided with an address map field to a terminal other than the third terminal .
[0014]
Furthermore, the present invention is a case where any one of a plurality of terminals participating in the network leaves the network,
After receiving a synchronization word from a terminal other than the leaving terminal, the leaving terminal obtains an address indicating that the terminal leaving the address map field provided in the synchronization word does not participate in the network. And steps to
Sending a synchronization word provided with an address map field in which an address indicating that the leaving terminal does not participate is sent to another terminal other than the leaving terminal by the leaving terminal. .
[0016]
DETAILED DESCRIPTION OF THE INVENTION
In a wireless LAN and a home network, data traffic of devices connected to the network is various, and there are not only terminal-terminal connections but also asymmetric communication and broadcast communication forms.
[0017]
In the wireless communication method of the present invention, it is possible to efficiently perform wireless control by processing efficient media access in a lower layer close to wireless. In addition, it is possible to configure a fully distributed terminal self-supporting network, and it is possible to easily manage even if multiple terminals are participating in the network without using a complicated protocol. Because the terminal operates while monitoring the synchronization word, it is easy to join / leave the network. In addition, resource management on the network is facilitated by multiplexing the radio band with fixed-length packets. Furthermore, each terminal can use a plurality of fixed-length packets, and in addition to bidirectional communication, asymmetric communication and broadcast communication can also be handled.
[0018]
FIG. 1 shows an example of an embodiment of a communication control method of the present invention. FIG. 1 shows an example in which a network is constructed in a home and DVD1, ATV2, and GW3 are connected by the communication method of the present invention. In FIG. 1, DVD 1 transmits MPEG2 video on a video disc to ATV 2. The gateway GW 3 is connected to the partner TV phone 5 via the ISDN line 4, exchanges image / sound information from the partner TV phone 5 with the ATV 2, and displays an image from the partner on the ATV 2. Therefore, ATV2 displays both video from DVD1 and video from GW3. Also, the voice from here is sent from ATV2 to GW3.
[0019]
FIG. 2 shows a transmission order of radio signals and a band to be used for realizing the communication in FIG. Following the synchronization word SYC21, the DVD 1 sends out the video signal T1. Even if the video signal T1 is generally encoded, it takes a time of 4 packets because a wide band is required. The video signal T1 transmitted from the DVD 1 can receive both ATV2 and GW3 as wireless signals, but the data processing unit of the terminal determines whether it can be received. In this case, the ATV2 receives and reproduces the image. Subsequent to DVD1, ATV2 sends audio signal T2. The audio signal T2 occupies a time corresponding to one packet because the band is narrower than the video signal T1. The receiving operation is the same as described above. Next, the GW 3 sends a signal with the image / sound information T3 taking 2 packets. If there is a vacancy in the band, a vacant packet is entered, the synchronization word SYC continues after a certain time, and the above operation is repeated.
[0020]
By performing such operations, various communication modes can be realized even when multiple terminals exist in the network, and asymmetrical communication and broadcast communication are possible in addition to bidirectional communication. It becomes.
[0021]
Here, the frame 22 indicates a bandwidth determined by a radio frequency band to be used and a modulation method. For example, when a 2.4 GHz radio frequency is used, a band of about 10 Mbps can be obtained. The packet 23 is obtained by dividing a frame into fixed time units.
[0022]
Here, in detail, a non-data section is provided between one frame and the next frame to absorb a time difference generated from EOF data (to be described later) and a clock error generated in each terminal.
[0023]
FIG. 3 shows the synchronization management method of the present invention. Since the wireless communication control method of the present invention is based on distributed processing, synchronization management is also performed by each terminal participating in the network. The synchronization management according to the present invention is performed by a terminal connected to the network carrying around the synchronization word transmission timing and sequentially transmitting the synchronization word. FIG. 3 is a diagram showing a state of synchronization management in the communication state of FIG. First, the DVD 1 sends out the synchronization word 31a. Subsequently, according to the time ratio of the packet 23 in the frame 22 shown in FIG. 2, each of the DVD1, ATV2, and GW3 transmits the transmission data. After there is an empty packet, ATV 2 next sends out the synchronization word 32. Subsequently, the GW 3 sends out the synchronization word 33. In this way, each terminal sends out the synchronization word in turn, so that each terminal can independently manage the synchronization of the network and create the signal transmission timing. At the same time, since the synchronization management is distributed, Easy to join / leave.
[0024]
The sending order of the synchronization word is performed according to the address map field described below, but the synchronization word for one frame is not sent as 34 for new participation in the network.
[0025]
FIG. 4 is a diagram showing the address map field of the present invention. The address map field is on the synchronization word and is sent out by each terminal as shown in FIG. The address map field grasps the terminals participating in the network, and each terminal manages the sending order of the synchronization words according to FIG. A terminal participating in the network monitors an address map field transmitted from another terminal, and obtains the youngest address among available addresses.
[0026]
FIG. 4 is a diagram for explaining a procedure by which the GW 3 in FIG. 1 acquires an address. The address map field 41a is a state where the GW 3 is not participating in the network. Further, the address management table 42a on the GW 3 also indicates that no bit is set and does not participate in the network. When the GW 3 joins the network, the address map field 41a is monitored, and after checking the third free space from the left, the bit is set in the third address [2] from the left in its own address management table 42a. 42b. At that time, a bit is set third from the left of the address map field 41b on the synchronization word transmitted by the user.
[0027]
FIG. 5 is a diagram for explaining terminal management, synchronization word transmission, and network participation methods using the address map field of the present invention. First, the DVD 1 is turned on with nothing participating in the network. The DVD 1 monitors the transmission of the synchronization word from other terminals, but since there is no transmission of the synchronization word, the youngest address [0] 51 is acquired and the synchronization word 52 is transmitted by itself as described in FIG. To do. Since there is no terminal other than DVD1, the next sync word is empty for new participation, and DVD1 with the youngest address [0] following the empty sends out the sync word again (FIG. 5A). .
[0028]
Next, the power supply of ATV2 is turned on. The ATV 2 monitors the synchronization word and knows from the address map field of the synchronization word sent from the DVD 1 that there is one terminal participating in the network and its address is [0]. Therefore, the ATV 2 acquires the address [1] 53 and, after the DVD 1 transmits the synchronization word, transmits the synchronization word 54 in the synchronization word portion opened for new use. At this point, the DVD 1 knows that terminals other than itself have joined the network. Since there are two terminals participating in the network, the next sync word becomes empty after ATV 2 sends the sync word. [0] DVD1 and [1] ATV2 send out synchronization words in ascending order of address following the empty space (FIG. 5B).
[0029]
Subsequently, the power of the GW 3 starts up. In the same manner as described above, the GW 3 monitors the synchronization word and knows that there are two terminals participating in the network and the addresses are [0] and [1]. The GW 3 acquires the address [2] 55, sends out the synchronization word 56, and participates in the network (FIG. 5C). Thereafter, it is possible to join the network in the same way.
[0030]
FIG. 6 is a diagram for explaining a method of leaving the network according to the present invention. In the state where DVD1, ATV2, and GW3 are participating in the network (FIG. 6A), when ATV2 normally leaves, when sending the last synchronization word 61 to leave, its own address [ 1] is turned OFF to leave the network. DVD1 and GW3 can identify that one terminal has detached by monitoring the synchronization word (FIG. 6B).
[0031]
On the other hand, there may be a case where the terminal cannot be normally disconnected due to a failure of the terminal. At this time, the transmission content of the synchronization word 62 of DVD1 and the absence of the transmission of the synchronization word from ATV2 are monitored by GW3, and GW3 detects the abnormality of ATV2 and rewrites synchronization word 63 (FIG. 6C). ). As described above, by managing the terminal using the address map field on the synchronization word, the management of the terminal on the network and the transmission management of the synchronization word can be easily performed.
[0032]
FIG. 7 explains the resource management field indicating the packet usage status on the frame of the present invention. Similar to the address map field, the resource management field is present on the synchronization word and indicates the position of the used packet. Since all the terminals participating in the network monitor the synchronization word, it is possible to know the traffic congestion on the network and the packets that can be used by monitoring the resource management field.
[0033]
In FIG. 7, the terminal monitors the resource management field 71a of the synchronization word, and if there is a vacant resource when transmitting its own synchronization word, the resource bit at the vacant position is turned on and the synchronization word 71b is transmitted. The packet is transmitted according to the bit position set by. The packet used by itself is held until the next synchronization word is transmitted. When there is no need for data transmission, the resource bit that was turned on at the time of sending the synchronization word is turned off.
[0034]
FIG. 8 shows a frame configuration of the present invention. The frame is composed of synchronization words SYC 81 to 83, a data packet 84 and an EOF 85. The configuration of the synchronization word (SYC) includes an SOF 81 indicating the beginning of the frame, an address map field AMF 82, and a resource management field 83. EOF85 represents the end of the frame. Details of each are as described above.
[0035]
FIG. 9 shows a wireless communication terminal for realizing the wireless communication method of the present invention. The radio unit 91 includes a radio unit 91 that transmits and receives radio signals, a radio control unit 92 that controls access to the radio unit, a data processing unit 93 that processes application data, and a radio input / output unit 94.
[0036]
【The invention's effect】
The present invention includes a step of monitoring whether a synchronization word is transmitted from a terminal other than the first terminal in the plurality of terminals by the first terminal in the plurality of terminals, when the sync word from another terminal other than the first terminal is not sent, a step of acquiring an address indicating that the first terminal has joined the network address map field provided in the synchronization word Sending a synchronization word provided with an address map field in which an address indicating that the first terminal has joined is sent by the first terminal to another terminal other than the first terminal; A step of monitoring whether a synchronization word is transmitted from a terminal other than the second terminal by a second terminal in the terminal, and a second terminal other than the second terminal by the second terminal end When the synchronization word is transmitted from the end, the step of receiving the synchronization word, and after receiving the synchronization word from the other terminal other than the second terminal by the second terminal, An address map field in which an address indicating that the second terminal has joined the network is acquired in an address map field, and an address map in which an address indicating that the second terminal has joined is acquired by the two terminals A step of sending a synchronization word provided with a field to another terminal other than the second terminal, and a third terminal in the plurality of terminals sending the synchronization word from another terminal other than the third terminal A step of monitoring whether the synchronization word has been sent, and a step of receiving the synchronization word when the third terminal sends a synchronization word from another terminal other than the third terminal. After the third terminal receives a synchronization word from another terminal other than the third terminal, the third terminal joins the network in the address map field provided in the synchronization word. A terminal other than the third terminal, and a synchronization word provided with an address map field in which an address indicating that the third terminal has participated is acquired by the third terminal. Can be easily managed even if a plurality of terminals participate in the network without using a complicated protocol, and all terminals operate while monitoring the synchronization word. This facilitates network participation.
[0037]
Further, according to the present invention, the terminal that leaves the address map field provided in the synchronization word after the synchronization word from the terminal other than the leaving terminal is received by the leaving terminal does not participate in the network. To the other terminal other than the terminal that leaves the synchronization word provided with the address map field in which the address indicating that the leaving terminal does not participate is acquired by the leaving terminal Since all terminals operate while monitoring the synchronization word, it is easy to leave the network.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a wireless communication method of the present invention.
FIG. 2 is a diagram illustrating a transmission order of radio signals and a band to be used according to the present invention.
FIG. 3 is a diagram showing a synchronization management method of the present invention.
FIG. 4 is a diagram showing an address map field of the present invention.
FIG. 5 is a diagram for explaining a terminal management, a synchronization word transmission, and a network participation method using the address map field of the present invention.
FIG. 6 is a diagram illustrating a method for leaving a network according to the present invention.
FIG. 7 is a diagram showing a resource management field indicating a packet usage status on a frame according to the present invention.
FIG. 8 is a diagram showing a frame configuration of the present invention.
FIG. 9 is a diagram showing an embodiment of a wireless communication terminal for realizing the wireless communication method of the present invention.
FIG. 10 is a diagram showing a wireless control method used in a conventional wireless LAN.
[Explanation of symbols]
1 DVD
2 ATV
3 GW
4 ISDN
5 Videophone 21 Sync word 22 Frame 23 Packet

Claims (2)

When communicating between a plurality of terminals, the wireless band used between the plurality of terminals is shared, and when each terminal communicates, in order to grasp the terminals participating in the network, A wireless communication method for ensuring synchronization of the entire network by sending out a synchronization word provided with an address map field for managing the sending order,
Monitoring whether a synchronization word is transmitted from a terminal other than the first terminal in the plurality of terminals by a first terminal in the plurality of terminals;
The first terminal has joined the network in the address map field provided in the synchronization word when no synchronization word is sent from the other terminal other than the first terminal by the first terminal. Obtaining an address indicating
Sending a synchronization word provided with an address map field in which an address indicating that the first terminal has joined has been provided by the first terminal to another terminal other than the first terminal;
Monitoring whether a synchronization word is transmitted from another terminal other than the second terminal by a second terminal in the plurality of terminals;
Receiving the synchronization word when the second terminal is sending a synchronization word from a terminal other than the second terminal; and
After the second terminal receives a synchronization word from another terminal other than the second terminal, the second terminal joins the network in an address map field provided in the synchronization word. Obtaining an address to indicate;
Sending a synchronization word provided with an address map field in which an address indicating that the second terminal has joined has been provided by the second terminal to another terminal other than the second terminal;
Monitoring whether a synchronization word is transmitted from a terminal other than the third terminal by a third terminal in the plurality of terminals;
Receiving the synchronization word when the third terminal is sending a synchronization word from a terminal other than the third terminal; and
After the third terminal receives a synchronization word from a terminal other than the third terminal, the third terminal has joined the network in an address map field provided in the synchronization word. Obtaining an address to indicate;
Sending a synchronization word provided with an address map field in which an address indicating that the third terminal has joined has been provided by the third terminal to another terminal other than the third terminal; A wireless communication method comprising: If any of the devices participating in the network leaves the network,
An address indicating that the leaving terminal does not participate in the network in the address map field provided in the synchronization word after the synchronization word is received from the terminal other than the leaving terminal by the leaving terminal. A step to obtain,
Sending a synchronization word provided with an address map field in which an address indicating that the leaving terminal does not participate is sent by the leaving terminal to another terminal other than the leaving terminal. The wireless communication method according to claim 1.

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