JP3354016B2 - Wireless network communication method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless network communication system, and more particularly, to a wireless system for realizing an environment in which a plurality of groups can simultaneously perform network communication on different wireless channels. For example, it is applied to indoor wireless communication and mobile communication.

[0002]

2. Description of the Related Art Known documents describing conventional network communication systems include, for example, Japanese Patent Laid-Open No. 6-2998.
No. 1 publication. The thing of this publication is a local area network for receiving a signal on a wireless transmission channel, including a receiving device for receiving a signal, and a transmitting device for transmitting a signal, wherein the receiving device receives the signal via a transmission channel. A high local area network (LAN) is provided by including a reception level determination device that indicates a signal level, a threshold level circuit device that provides a level instruction signal, and a transmission control device that controls the operation of the transmission device based on the level instruction signal. ) To achieve performance.

[0003] Japanese Patent Application Laid-Open No. 5-260051 discloses that in a network composed of a plurality of wireless terminals and a central station capable of transmitting and receiving all of them, the entire available frequency band is a message channel, a channel tone upstream, and a channel tone uplink. The present invention provides a wireless system that makes the central office have a role of a repeater by dividing the signal into three parts, that is, channel tone downlink, and that facilitates transmission and reception between terminals.

[0004]

According to the above-mentioned publication, the target wireless local area network (LAN) is a wired LAN widely used at present, and is used for connection between terminals. It aims to replace the cable with a wireless link. Also, Japanese Patent Laid-Open No. 6-29
9 8 Wireless LAN according to one publication is that Ethernet access method is a wired LAN are currently the most popular (C
SMA), and is a peer-to-peer wireless LAN in which one terminal shares one wireless channel. Also, Japanese Patent Laid-Open No. 5-2
The wireless LAN described in Japanese Patent Application Laid-Open No. 60051 is a wireless LAN in which a central station is provided in addition to wireless terminals to control a wireless channel in order to improve communication throughput, and takes a communication form via the central station. The purpose of both is to realize the currently used wired LAN usage form wirelessly, and assumes network communication in a closed environment such as in an office.

However, in recent years, note-type personal computers (PCs) have been increasing, and in view of the fact that notebook-sized computers called portable information terminals have begun to be used, a plurality of these users are required to use these portable computers. It is thought that an environment (mobile network) in which networks can be established and communicated with each other regardless of where they are located will be required. This mobile network environment realizes, for example, a paperless meeting regardless of the location inside or outside the office.

[0006] In this mobile network, it is considered that there are many environments in which a plurality of groups of users are used contiguously, and the form of communication is frequently exchanged with data requiring real-time such as meetings. More and higher traffic. Therefore, the wireless LAN share one radio channel, such as JP-A 6-299 8 1 discloses in all terminals, problems obviously leads to a decrease in throughput occurs. Also, Japanese Patent Application Laid-Open
In the wireless LAN disclosed in -260051, a repeater called a central office is required, so that there is a local limitation that a network can be configured only at a place where the central office is installed.

[0007] The present invention has been made in view of such circumstances, and provides a plurality of wireless channels with extremely small interference, and arbitrarily selects one wireless channel when configuring a network in a group to configure a network. In addition to realizing an environment in which multiple groups can simultaneously perform network communication on different wireless channels, secure wireless channels in the wireless system by changing spreading codes, and when a group attempts to start communication or It is an object of the present invention to provide a wireless network communication system having a method of selecting a wireless channel, that is, a spreading code in the wireless network.

[0008]

According to the present invention, in order to solve the above-mentioned problems, (1) a plurality of groups arbitrarily constituted by a plurality of wireless terminals are distributed equally among wireless terminals belonging to each group. In a wireless network communication system for performing network communication, when each group tries to start communication when each group performs network communication by code division multiplexing with an individual spreading code,
The terminal serving as the host of the group first senses all spreading codes to be used, and sends a confirmation packet for confirming whether or not the code is being used with a certain free code obtained as a result, Wait for a response from another group with the same code within a certain period of time, and if no response from another group is received, start communication with the code as a spread code of the group, while receiving a response from another group Sends a confirmation packet in the same way with the next empty code,
Repeating the operation of waiting for a response from another group, determining a spreading code to be used in the group, and further,
(2) when changing to the next free code, changing in an order determined for each group; and (3) when changing to the next free code, changing in a random order; Further, (4) an arbitrary code is sensed, and if the code is not being used, a confirmation packet is transmitted with the code, and a response from another group is received within a certain time with the same code. If the response is not received, the communication is started with the code as the spread code of the group. On the other hand, when the response from the other group is received, the same code is sensed with the next code, the confirmation packet is transmitted, and the response from the other group is transmitted. The operation of waiting is repeated to determine the spreading code to be used in the group. (5) In (4), the code is determined for each group when the code is changed. It is incidentally code change, further, (6) In embodiment (4), carrying out the code changes in a random order when making the code changes, further,
(7) In any one of the above (1) to (6), when another group receiving the confirmation packet responds, information of a code currently used around the group is added. (8) In any one of the above (1) to (6), when a group that has received a confirmation packet with the used code responds, all terminals in the group that have received the confirmation packet respond. Or,
(9) In a wireless network communication system in which a plurality of groups arbitrarily configured by a plurality of wireless terminals perform peer-to-peer distributed network communication among wireless terminals belonging to the respective groups, each group is code division multiplexed by an individual spreading code. When performing network communication according to the above, host terminals in other groups periodically send busy codes when not performing communication in the group, and when a group attempts to start communication, The terminal serving as a host senses all spread codes for each code for a certain time and selects a code that is not sensed. (10) In (9), each terminal in each group is Sending out the in-use code periodically when no communication is performed within the In a wireless network communication system in which a plurality of groups arbitrarily configured by line terminals perform equal distributed network communication between wireless terminals belonging to each group, each group performs network communication by code division multiplexing using individual spreading codes. At that time,
Starting communication with an arbitrary code, and changing the code when it is found that the same code as another group is being used during the communication. Further, (12) In the above (11),
Changing the code when the throughput of intra-group communication falls below a certain threshold, and (1)
3) In the above (11), the code change is performed when the frequency of carrier sense during intra-group communication is equal to or higher than a certain threshold value. Further, (14) the above (11), (11) 12) or (13), the order of the code change is performed in an order determined by each group;
(15) In the above (11), (12) or (13), the code change order is randomly performed, or (16) a plurality of groups arbitrarily configured by a plurality of wireless terminals are included in each group. In a wireless network communication system that performs peer-to-peer distributed network communication between wireless terminals belonging to a group, when each group performs network communication by code division multiplexing with an individual spreading code,
When a group attempts to start communication, the terminal that is the host of the group first senses all spreading codes to be used, and if it finds that some other group is communicating, it uses the code to Inquiring about a code being used around the group, selecting a used code from the information and the result sensed by the own station, and (17)
(16) In the above (16), when there are a plurality of busy codes as a result of sensing all the codes, an inquiry is made with a code having the largest sensed correlation value.

[0009]

According to the wireless network communication system of the present invention having the above-described structure, a plurality of groups arbitrarily configured by a plurality of wireless terminals perform peer-to-peer distributed network communication between wireless terminals belonging to each group. In (1) when each group performs network communication by code division multiplexing using an individual spreading code, when a certain group attempts to start communication, a terminal serving as a host of the group firstly uses the entire spreading code to be used. Senses a code, sends a confirmation packet to confirm whether the code is in use with a certain free code obtained as a result, and waits for a response from another group within a certain time with the same code If no response is received from another group, communication is started using the code as a group spreading code. Upon receiving a response from another group sends a similarly acknowledgment packet at the next available code, repeated a response waiting operation for the other group, after sensing the entire coding because it determines the spreading codes to be used in the group By sending a confirmation packet with an empty code,
To make sure that the code is actually being used,
An empty code can be reliably selected.

(2) Since the code is changed in the order determined for each group when changing to the next empty code, it is possible to avoid that a plurality of groups attempting to start communication at the same time select the same code. . (3) When changing to the next free code, the codes are changed in a random order, so that it is possible to avoid that a plurality of groups attempting to start communication at the same time select the same code. (4) Sense an arbitrary code, and if the code is not in use, send a confirmation packet with the code, wait for a response from the other group with the same code within a certain time, and receive a response from the other group. If the code is not received, the communication is started with the code as a spread code of the group. On the other hand, when a response from another group is received, the same code is sensed with the next code,
The operation of sending a confirmation packet and waiting for a response from another group is repeated, and the spreading code to be used in the group is determined.Therefore, every time a code sense is performed, a confirmation packet is sent and a busy packet is received. No need to sense code.

(5) When the code is changed, the code is changed in an order determined for each group.
In addition to the functions and effects of the above, the code sense is performed in the order determined for each group, so that it is possible to avoid that a plurality of groups attempting to start communication at the same time select the same code. (6) Since the code change is performed in a random order when performing the code change, the code effect is performed in a random order in addition to the operation and effect according to (4). A group can be prevented from selecting the same code. (7) When another group receiving the confirmation packet responds, the information of the code currently used in the vicinity of the group is added, so that the code of the peripheral group can be identified and the code can be selected more reliably. .

(8) When the group receiving the acknowledgment packet with the code in use responds, all the terminals in the group receiving the acknowledgment packet respond, so the busy packet notifying that the code is in use is transmitted. It can be received reliably. (9) When each group performs network communication by code division multiplexing using an individual spreading code, host terminals in other groups periodically transmit a busy code when communication within the group is not performed, When a group attempts to start communication, the terminal that is the host of the group senses all the spread codes for each code for a certain time and selects a code that was not sensed, so it is necessary to send a confirmation packet. Absent.

(10) When each terminal in each group is not performing communication in the group, the busy code is periodically transmitted, so that it is not necessary to transmit a confirmation packet, and the busy packet is reliably received. it can. (11) When each group performs network communication by code division multiplexing using individual spreading codes, communication starts with an arbitrary code, and when it is determined that the same code as another group is used during communication. To change
There is no need to sense every code.

(12) Since the code change in the method according to the above (11) is performed based on the throughput, communication without decreasing the throughput can be performed. (13) Since the code change in the method according to (11) is performed on the basis of the number of times of carrier sensing, it is not necessary to calculate the throughput and reliable communication can be performed. (14) Since the codes are changed in the method of (11) to (13) in the order determined by each group, the same code is selected when there are a plurality of stations that attempt to change the code in the same manner. Less likely.

(15) Since the codes are changed at random in the above-mentioned methods (11) to (13), there is a possibility that the same code is selected when there are a plurality of stations trying to change the code in the same manner. Lower. (16) When each group performs network communication by code division multiplexing using an individual spreading code, when a certain group attempts to start communication, a terminal serving as a host of the group firstly uses all spreading codes to be used. Sense,
When it is known that another group is communicating, the code is used to inquire about the code currently being used around the group, and the used code is selected from the information and the result sensed by the own station. An empty code can be selected. (17) When there are a plurality of in-use codes as a result of sensing all the codes, the inquiry is made with the code having the largest sensed correlation value, so that the inquiry and the code information can be received with certainty, and therefore the free code selection can be made reliably. It can be performed.

[0016]

Embodiments will be described below with reference to the drawings. FIG. 1 is a configuration diagram for explaining an embodiment of a wireless network communication system according to the present invention, and is a configuration diagram of a wireless local area network for a mobile network. In the figure, 1a to 1d are wireless terminals, 2a to 2d
Is a wireless terminal, 3 is a wireless channel A (spreading code (a)), and 4 is a wireless channel B (spreading code (b)).

The wireless terminals that make up each group do not have the same relationship as a server and a client, but form a peer-to-peer distributed network during communication. The wireless channel for each group is performed by code division using different spreading codes. The present invention selects a radio channel or spreading code when a group is about to start communicating.

According to the present invention, a plurality of wireless terminals 1a to 1d, 2
Multiple groups 1 and 2 arbitrarily configured by a to 2d
Or a wireless network in which wireless terminals belonging to each group perform peer-to-peer distributed network communication. When each group performs network communication by code division multiplexing with an individual spreading code, when a certain group tries to start communication, a terminal serving as a host of the group first senses all spreading codes used, Sends a confirmation packet to confirm whether this code is in use with a certain free code obtained as a result, waits for a response from another group within a certain time with the same code,
If a response from another group is not received, communication is started using this code as a spread code of the group. On the other hand, when the response from the other group is received, the operation of transmitting the confirmation packet and waiting for the response from the other group is similarly repeated with the next empty code, and the spreading code to be used in the group is determined.

First, the invention described in claim 1 (Embodiment 1)
Will be described. FIG. 2 is a block diagram of a wireless terminal of the wireless network communication system according to the present invention, in which 11 is a spreading code generator, 12 is a correlation detector, 13 is a channel controller, 14 is a computer main body, 15 is a network controller, 16 is a transceiver and 17 is an antenna. First, an operation for transmitting and receiving will be described, and then a method of selecting a spreading code will be described.

Control of transmission / reception, selection of a wireless channel, control of communication within a group, and the like are realized by controlling the network controller 15 and the channel controller 13 from a computer. When transmitting, first, a transmission start signal is transmitted to the network controller 15 and transmission data is transmitted. The network controller 15 sets the transceiver 16 in the transmission mode, and transmits the transmission data to the transceiver 16 in a packet configuration suitable for the network.

The transceiver 16 multiplies the data signal to be transmitted by the spreading code generated by the spreading code generator 11, that is, spreads the frequency, converts it to a radio frequency, and transmits it from the antenna 17. Spreading code generator 11
Are n different spreading codes C (i) (i = 1,2,2
.., N) may be switched to have n encoders, or the codes stored in the memory may be switched and read. Here, a periodic signal called a pseudo-noise signal such as an M-sequence signal is generally used as the spreading code. For example, a code such as a preferred pair of an M-sequence signal that has a correlation as small as possible is used.

Next, the operation at the time of reception will be described. The received signal input from the antenna 17 is first converted from a radio frequency to an intermediate frequency or a baseband frequency in the transceiver 16 and is multiplied (despread) by the spreading code generated by the spreading code generator 11 to perform data demodulation. The network controller 13 extracts necessary data from the received packet signal from the transceiver 16 and sends it to the computer 14.

When communication is to be started, it is necessary to select a spreading code to be used in the group. In order to determine whether or not a certain spreading code is in use, the correlation detection unit 12 uses the transceiver 16 A received signal converted to an intermediate frequency or baseband frequency,
The degree of correlation with the reference spreading code signal from the spreading code generator 11 is detected using a correlation circuit. The correlation circuit, for example, when the reception channel signal is a baseband signal,
It consists of a multiplier, a low-pass filter, a mixer for RF or intermediate frequency signals, a band-pass filter and an envelope detector. There is also a method using a synchronous circuit such as a DLL. The correlation detector can also be configured by preparing matched filters for each spreading code.
These may be any method capable of obtaining a correlation calculation output, and may be an analog circuit or a digital circuit.

The next channel controller 13 switches the type of the reference spreading code signal of the spreading code generator 11 and receives a correlation output signal of each code with a received signal from the correlation detector 12 as a detection output signal.
If the correlation output signal is equal to or greater than a certain threshold, it is determined that the spread code is in use. Further, at the time of transmission, the spread code generator 11 is controlled so that the selected spread code signal is supplied to the transceiver 16.
Is controlled to be in a transmission / reception state using the code.

FIG. 3 is a flowchart of a spreading code selection method according to the present invention. Hereinafter, description will be made in order according to each step (S). This spreading code selection method is performed by one terminal (called a host terminal) in the group. First, the channel controller receives the network communication start request from the computer body, controls the correlation detection unit,
Start detection of the reception channel signal. First, sensing is performed with the reference spreading code C (1) (S1). Here, "sense" means that the correlation detection output for the code is output to the channel controller, and when the correlation detection output exceeds a certain threshold value, the code is determined to be in use.

Thereafter, by sequentially switching the reference spreading code of the spreading code generator as C (i + 1), all the codes (C1) to (C (n)) are sensed (S4). The results of the code sense for all these codes are transmitted to the computer, and the resulting free codes are
(J) (j = 1, 2,..., M). Next, transmission control is performed on the transceiver, and a confirmation packet for confirming whether or not this channel is actually used is transmitted with an empty code C.
It is transmitted at o (j) (S8). This is because even if the code is determined to be unused as a result of the code sensing, there is a possibility that the code is sensed while another group is suspending communication.

FIG. 4A shows an example of the signal arrangement of the confirmation packet.
Shown in In FIG. 4A, a preamble is a signal for despreading a spreading code and for synchronizing bits of demodulated data, and a header portion following the preamble contains group or personal information. After that, a control code area is provided, in which a code (for example, “CK”) indicating a confirmation packet is entered. Thereafter, normal data is input. In this case, since there is no data to be input, the data can be omitted.

When the confirmation packet is transmitted, the code Co
If there is a group using (j), the host terminals in that group send a busy packet indicating that the channel is in use (S9). FIG. 4B shows an example of the signal arrangement of the busy packet. The control code indicating that the control code is a busy packet (for example, “B
S ”). The host terminal that has received the busy packet sets the reference spreading code to the next available code Co (j +
The procedure of transmitting the confirmation packet as 1) is repeated (S
10). When it is confirmed that the busy packet is not received by the empty code Co (j), the code Co (j) is selected as the code of the group (S11). When a busy packet is received with all the empty codes Co (j) (j = 1, 2,..., M), the procedure is repeated after waiting for a certain time and starting with the sense of the empty code. This process may be restarted from the transmission of the confirmation packet, or the code selection may be ended for the time being.

Next, the invention according to claim 2 (Embodiment 2)
Will be described. FIG. 5 is another flowchart of a spreading code selection method according to the present invention. Hereinafter, description will be made in order according to each step (S). In the spreading code selection method shown in the first embodiment, the order of sensing all codes is as follows.
The system is fixed as C (1), C (2), C (3),..., C (n), but this order is different for each group, Cg (1), Cg (2), Cg ( 3), ..., C
g (n) (S12). By doing so, since the order of sending confirmation packets based on empty codes differs for each group, when a plurality of groups try to start communication at the same time, the confirmation packets may be sent with the same empty code. Disappears.

Next, the invention according to claim 3 (Embodiment 3)
Will be described. FIG. 6 is still another flowchart of the spreading code selection method according to the present invention. Hereinafter, description will be made in order according to each step (S). The sensing method for all codes is performed as shown in the first embodiment. Next, a confirmation packet is transmitted using an empty code (S29), and a busy packet is received (S30). At this time, the code is changed in a random order. J = rn in FIG.
The symbol d () is (S28), and the argument j is a random integer from 1 to m. However, the same number is selected only once. By doing this,
A random empty code can be selected from m empty codes Co (j) (j = 1, 2,..., m). As a result, when a plurality of groups try to start communication at the same time, the confirmation packet is not transmitted with the same empty code.

Next, the invention according to claim 4 (Embodiment 4)
Will be described. FIG. 7 is a further flowchart of the spreading code selection method according to the present invention. Hereinafter, description will be made in order according to each step (S). In this embodiment, not all codes are sensed first, but it is determined whether each code is in use and then a confirmation packet is transmitted.

The code C (i) is sensed (S44), and it is determined whether this code is being used (S45). If it is in use, the procedure of changing the code to C (i + 1) and performing sensing is repeated (S46). If the code C (i) is not in use, a confirmation packet is transmitted with the code C (i) (S47). It waits for reception of a busy packet from another group with the code C (i) (S43), and upon receiving the busy packet (S48), repeats the procedure of changing the code to C (i + 1) and performing sensing (S46). If no busy packet is received, the code C (i) is selected (S49).

Next, the invention according to claim 5 (Embodiment 5)
Will be described. FIG. 8 is a further flowchart of the spreading code selection method according to the present invention. Hereinafter, description will be made in order according to each step (S). In the code selection method shown in the fourth embodiment, the order of changing codes is C
The system is fixed as (1), C (2), C (3),..., C (n), but this order is different for each group, Cg (1), Cg (2), Cg (3). ),…, Cg
(N) (S50, 51). By doing so, since the order of sending confirmation packets based on empty codes differs for each group, when a plurality of groups try to start communication at the same time, the confirmation packets may be sent with the same empty code. Disappears.

Next, the invention according to claim 6 (Embodiment 6)
Will be described. FIG. 9 is a further flowchart of the spreading code selection method according to the present invention. Hereinafter, description will be made in order according to each step (S). In this embodiment, the order of the code sense described in the fourth embodiment is randomly performed. I = rnd () in FIG. 9 corresponds to (S6
4) The argument i is a random integer from 1 to n. However, the same number is selected only once. By doing so, n codes C (i) (i =
A random code can be selected from 1, 2,..., N). As a result, when a plurality of groups try to start communication at the same time, the confirmation packet is not transmitted with the same empty code.

Next, the invention according to claim 7 (Embodiment 7)
Will be described. FIG. 10 is still another flowchart of the spreading code selection method according to the present invention. Hereinafter, description will be made in order according to each step (S). In the code selection method according to the first to sixth embodiments, the code change can be simplified by adding the currently used code information known in the group to the busy packet transmitted from the other group.

When the other group receives the confirmation packet of the code being used, it sends out a busy packet having a signal arrangement as shown in FIG. In FIG. 11, after the control code, the numbers (1 to n) of the in-use codes of the peripheral groups recognized by the other groups are inserted. The host terminal that has received this busy packet changes the code to the next available code excluding these busy codes (S13). FIG. 10 shows a case in which the present invention is applied to the method of claim 1. However, the present invention can be similarly applied to the methods of claims 2 to 6. As a result, when the present invention is applied to the method according to the first to third aspects, the acknowledgment packet is not transmitted by the used code. In addition, when the present invention is applied to the systems of claims 4 to 6, there is no need to transmit a sense / confirmation packet using a busy code.

Next, the invention according to claim 8 (Embodiment 8)
Will be described. FIG. 12 is a block diagram for explaining another embodiment of the wireless network communication system according to the present invention, and the reference numerals in the figure are the same as those in FIG. In the method according to the first to seventh aspects, the acknowledgment packet is received by another group, and the host terminal of the group transmits the busy packet. However, as shown in FIG. 12, when there is a certain distance between groups, the confirmation packet may not reach the host terminal.
Further, it may occur when the host terminal of another group cannot receive the confirmation packet for some reason. Therefore, in the invention according to claim 8, all terminals that have received the confirmation packet among the terminals of the other groups transmit a busy packet.

Next, the invention according to claim 9 (Embodiment 9)
Will be described. FIGS. 13 and 14 are flowcharts for explaining the operation of the host terminal. Hereinafter, description will be made in order according to each step (S). FIG. 14 is a flowchart illustrating the operation of another group of host terminals that are already communicating. The host terminals of other groups have timers, and first set Timer = 0 (S8).
1) When transmission / reception is completed (S82), Timer is started (S83). When transmission / reception is started again (S8)
4) Timer is reset again (Timer = 0), but if transmission / reception does not start and Timer exceeds the set time T (S8)
5) Send a busy packet (S86). The busy packet has a signal arrangement as shown in FIG. 4B or FIG. Therefore, the group during communication does not lose communication for more than the set time T seconds.

FIG. 13 is a flowchart showing the operation of the host terminals of the group which is about to start communication. According to the present invention, the code in use can always be sensed if the code sense is performed for T seconds, so that there is no need to send a confirmation packet or receive a busy packet.

Next, the invention according to claim 10 (Embodiment 1)
0) will be described. According to the tenth aspect, in the method of the ninth embodiment, the operation of the host terminals in the communicating group shown in FIG. 14 is performed by all the terminals in the communicating group. As shown in FIG. 12 used in the description of the eighth embodiment,
When there is a certain distance between groups, a busy packet may not reach the host terminal, or the host terminal may not be able to receive the busy packet for some reason. Therefore, this problem can be avoided by transmitting a busy packet to all terminals in another group.

Next, the invention according to claim 11 (Embodiment 1)
1) will be described. FIG. 15 is a further flowchart of the spreading code selection method according to the present invention. Less than,
The description will be given in order according to each step (S). First, the host terminal of the group that intends to start communication has the code C
Communication is started in (i) (S92). Thereafter, when a packet of another group is received with the same code C (i) (S9
3) Change the code to C (i + 1) and perform communication (S9)
4). Whether the received packet belongs to the own group or another group can be determined based on group information or personal information in the packet. FIG. 16 shows a signal arrangement diagram of the packet. Group information or personal information is put in the header section in this figure.

Next, the invention according to claim 12 (Embodiment 1)
4) will be described. FIG. 17 is a further flowchart of the spreading code selection method according to the present invention. Less than,
The description will be given in order according to each step (S). In the method described in the eleventh embodiment, the code is changed when a packet of another group is received. However, in the present invention, the computer constantly monitors the throughput during communication (S9).
5) When the throughput falls below the set threshold, the code is changed. The throughput decreases when the interference of packets from other groups increases or when some interference or noise increases. Therefore, according to this method, the throughput can be maintained at a certain value or more.

Next, the invention according to claim 13 (Embodiment 1)
3) will be described. FIG. 18 is still another flowchart of the spreading code selection method according to the present invention. Less than,
The description will be given in order according to each step (S). In the system of the eleventh embodiment, when changing the code, the number of times of carrier sense is monitored (S96), and when the number of times of carrier sense exceeds the set threshold value, the code is changed. Since communication within a group is performed by CSMA (Carrier Sense Multiple Access), carrier sense is performed when transmission is attempted. However, when another group uses the same code, carrier sense is performed. The number increases rapidly. Therefore, when the number of times of carrier sense becomes large, it is considered that another group is using the same code, or it is difficult to communicate with the code for some reason.
Make code changes.

Next, the invention according to claim 14 (Embodiment 1)
4) will be described. FIG. 19 is still another flowchart of the spreading code selection method according to the present invention. Less than,
The description will be given in order according to each step (S). Examples 11 to
In the present invention, the order of changing codes in the thirteenth method is changed for each group. FIG. 19 is applied to the eleventh embodiment, but may be applied to the twelfth or thirteenth embodiment. The code Cg (i) represents a code having an order determined for each group (S97). Examples 11 to
In the method of the thirteenth, all groups start communication with the same code and the order of changing the code is the same, so that the same code is often used. Therefore, if the order is changed for each group, the frequency can be reduced.

Next, the invention according to claim 15 (Embodiment 1)
5) will be described. FIG. 20 is still another flowchart of the spreading code selection method according to the present invention. Less than,
The description will be given in order according to each step (S). Examples 11 to
The order of changing codes in the method of No. 13 is randomly performed (S98). FIG. 20 is applied to the eleventh embodiment,
The present invention may be applied to the twelfth or thirteenth embodiment. According to this method, the possibility of using the same code as other groups is reduced.

Next, the invention according to claim 16 (Embodiment 1)
6) will be described. FIG. 21 is a further flowchart of the spreading code selection method according to the present invention. Less than,
The description will be given in order according to each step (S). First, all the codes are sensed (S101 to 104), and then an inquiry packet is transmitted with the used code C (j) (j = 1 to n) (S105). FIG. 22A shows a signal arrangement diagram of the inquiry packet. The inquiry packet is shown in the control code area. Here, for example, a code “QT” is included. The host terminals of the group that have already communicated with the code C (j) return the code information used in the vicinity (S106). FIG. 22B shows a signal arrangement diagram of the code information packet. In this packet, a code number used after a code (“CI”) indicating a code information packet is arranged in the control code. The host terminal receiving this code information packet determines the code C (k) to be used together with the result sensed by the local terminal. That is, the code C (k) is determined by excluding the code included in the received in-use code information in addition to the code that the local station senses and determines that the code is in use (S
107).

Next, the invention according to claim 17 (Embodiment 1)
7) will be described. FIG. 23 is still another flowchart of the spreading code selecting method according to the present invention. Less than,
The description will be given in order according to each step (S). A correlation value is recorded when sensing all codes (S108). Code C with the highest correlation value after sensing all codes
(J) Transmission of an inquiry packet in (j = 1 to n) (S
109), a code information packet is received (S10).
6). The highest correlation value means that the best communication can be expected because the station is closest. Therefore, the exchange of the inquiry packet and the code information packet can be reliably performed.

[0048]

As is apparent from the above description, the present invention has the following effects. (1) Effects corresponding to claim 1: When each group performs network communication by code division multiplexing using an individual spreading code, when a certain group attempts to start communication, a terminal serving as a host of the group, First, all spread codes to be used are sensed, and a check packet for checking whether the code is in use with a certain free code obtained as a result is transmitted, and a response from another group is sent using the same code. Waits for reception within a certain time, and if no response from another group is received, starts communication with the code as a spread code of the group. the delivery
And, repeating the operation for waiting for a response from the other group,
Since the spreading code to be used in the group is determined, all codes are sensed, and then a check packet is transmitted with an empty code, so that whether the code is actually used is surely selected. be able to. (2) Effect corresponding to claim 2: when changing to the next empty code, the code is changed in the order determined for each group, so that a plurality of groups trying to start communication at the same time select the same code. Can be avoided. (3) Effect corresponding to claim 3: Since the code is changed in a random order when changing to the next empty code, it is possible to avoid that a plurality of groups attempting to start communication at the same time select the same code. . (4) Effect corresponding to claim 4: Sense an arbitrary code, send a confirmation packet with the code if the code is not in use, and wait for reception of a response from another group with the same code within a certain time If a response from another group is not received, the communication is started with the code as a spread code of the group, while if a response from another group is received, the same code is sensed with the next code, and a confirmation packet is sent out. Since the operation of waiting for a response from another group is repeated and the spreading code to be used in the group is determined, every time code sensing is performed, a confirmation packet is sent and a busy packet is received, so it is necessary to sense all codes. Absent. (5) Effect corresponding to claim 5: when the code is changed, the code is changed in the order determined for each group. Therefore, in addition to the operation effect according to claim 4, the code sense is determined for each group. Therefore, it is possible to prevent a plurality of groups attempting to start communication at the same time from selecting the same code. (6) Effect corresponding to claim 6: Since the code change is performed in a random order when the code is changed, the code sense is performed in a random order in addition to the effect of the above (4). It is possible to prevent a plurality of groups attempting to start communication from selecting the same code. (7) Effect corresponding to claim 7: When another group receiving the confirmation packet responds, the information of the code currently used around the group is added, so that the code of the peripheral group can be more clearly understood. Can be selected. (8) Effect according to claim 8: When the group receiving the confirmation packet responds with the used code, all the terminals in the group receiving the confirmation packet respond, so that the code is being used. Can be reliably received. (9) Effect corresponding to claim 9: When each group performs network communication by code division multiplexing using individual spreading codes, host terminals in other groups are in use when not performing communication in the group. Since a code is transmitted periodically and a group tries to start communication, a terminal serving as a host of the group senses all spread codes for a certain time in each code and selects a code which is not sensed. There is no need to send a confirmation packet. (10) An effect corresponding to claim 10: when each terminal in each group does not perform communication within the group, the busy code is periodically transmitted, so that it is not necessary to transmit a confirmation packet, and it is ensured. Can receive a busy packet. (11) Effect corresponding to claim 11: When each group performs network communication by code division multiplexing using an individual spreading code, communication starts with an arbitrary code and the same code as another group is used during communication. The code is changed when it is found that it is not necessary to sense all the codes. (12) Effect corresponding to the twelfth aspect: Since the code change in the method according to (11) is performed based on the throughput, communication without decreasing the throughput can be performed. (13) Effect corresponding to claim 13: wherein the (11) for performing code changes in scheme key Yariasensu count to value determined by the throughput of the calculations can be performed unnecessary and reliable communication. (14) Effect corresponding to claim 14: Since the codes are changed in the method of (11) to (13) in the order determined by each group, there are a plurality of stations that have attempted to change the code in the same manner. Is less likely to select the same code. (15) Effect corresponding to claim 15: Since the code change in the method of (11) to (13) is performed at random, the same code is used when a plurality of stations try to change the code in the same manner. Less likely to choose. (16) Effect corresponding to claim 16: When each group performs network communication by code division multiplexing using an individual spreading code, when a certain group attempts to start communication, a terminal serving as a host of the group, First, all the spreading codes used are sensed, and when it is found that another group is communicating, a code currently in use around the group is inquired using the code, and the information and the own station sense. Since the used code is selected from the result, the empty code can be surely selected. (17) Effect corresponding to claim 17: As a result of sensing all the codes, if there are a plurality of in-use codes, an inquiry is made with the code having the largest sensed correlation value, so that the inquiry and the code information are reliably received. Therefore, it is possible to reliably select an empty code.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an embodiment of a wireless network communication system according to the present invention.

FIG. 2 is a configuration diagram of a wireless terminal of a wireless network communication system according to the present invention.

FIG. 3 is another flowchart of a spreading code method according to the present invention.

FIG. 4 is a diagram illustrating an example of a signal arrangement of a packet according to the present invention.

FIG. 5 is another flowchart of the spreading code method according to the present invention;

FIG. 6 is still another flowchart of the spreading code method according to the present invention;

FIG. 7 is still another flowchart of a spreading code method according to the present invention;

FIG. 8 is still another flowchart of the spreading code method according to the present invention;

FIG. 9 is still another flowchart of a spreading code method according to the present invention;

FIG. 10 is still another flowchart of a spreading code method according to the present invention;

FIG. 11 is a diagram illustrating an example of a signal arrangement of a packet according to the present invention.

FIG. 12 is a configuration diagram for explaining another embodiment of the wireless network communication system according to the present invention.

FIG. 13 is still another flowchart of a spreading code selection method according to the present invention.

FIG. 14 is still another flowchart of a spreading code selection method according to the present invention.

FIG. 15 is still another flowchart of a spreading code selection method according to the present invention.

FIG. 16 is a diagram illustrating an example of a signal arrangement of a packet according to the present invention.

FIG. 17 is still another flowchart of a spreading code selection method according to the present invention.

FIG. 18 is still another flowchart of a spreading code selection method according to the present invention.

FIG. 19 is still another flowchart of a spreading code selection method according to the present invention.

FIG. 20 is still another flowchart of a spreading code selection method according to the present invention.

FIG. 21 is still another flowchart of a spreading code selection method according to the present invention.

FIG. 22 is a diagram illustrating a signal arrangement example of a packet according to the present invention.

FIG. 23 is still another flowchart of a spreading code selection method according to the present invention.

[Explanation of symbols]

1a-1d: wireless terminal, 2a-2d: wireless terminal, 3 ... wireless channel A (spread code (a)), 4 ... wireless channel B (spread code (b)), 11 ... spread code generator, 1
2: Correlation detector, 13: Channel controller, 14 ...
Computer body, 15 ... Network controller,
16 ... transceiver, 17 ... antenna.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Yoshikatsu Nakagawa 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-4-138734 (JP, A) JP-A-6-326685 (JP, A) JP-A-8-97827 (JP, A) JP-A-8-125563 (JP, A) JP-A-8-125662 (JP, A) JP-A-8-125656 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H04L 12/28 H04B 1/707

Claims (17)

(57) [Claims] In a wireless network communication system in which a plurality of groups arbitrarily configured by a plurality of wireless terminals perform peer-to-peer distributed network communication among wireless terminals belonging to each group, each group is encoded by an individual spreading code. In performing network communication by division multiplexing, when a group attempts to start communication, a terminal serving as a host of the group first senses all spreading codes to be used, and obtains a certain free space obtained as a result. Sends a confirmation packet for confirming whether the code is being used by a code, waits for a response from another group within a certain time with the same code, and if no response is received from another group, the code Starts communication as the group spreading code, while receiving a response from another group, A wireless network communication system characterized by repeating the operation of transmitting a confirmation packet and waiting for a response from another group as described above to determine a spreading code to be used within the group. 2. The wireless network communication method according to claim 1, wherein when the code is changed to the next empty code, the code is changed in an order determined for each group. 3. The wireless network communication system according to claim 1, wherein when changing to the next empty code, the change is performed in a random order. 4. An arbitrary code is sensed, and if the code is not in use, a confirmation packet is transmitted with the code, a response from the other group is received within a certain time by the code, and a response from the other group is received. If no response is received, start communication with the code as a group spreading code,
When a response from another group is received, the same code is sensed with the next code, an operation of transmitting a confirmation packet and waiting for a response from the other group is repeated, and a spreading code to be used in the group is determined. The wireless network communication method according to claim 1. 5. The wireless network communication system according to claim 4, wherein when the code is changed, the codes are changed in an order determined for each group. 6. The wireless network communication system according to claim 4, wherein the code change is performed in a random order when the code is changed. 7. The system according to claim 1, wherein when another group receiving the confirmation packet responds, information of a code currently used around the group is added.
The wireless network communication method according to any one of the above. 8. The terminal according to claim 1, wherein all the terminals in the group receiving the confirmation packet respond when the group receiving the confirmation packet responds with the used code. The wireless network communication method according to 1. 9. In a wireless network communication system in which a plurality of groups arbitrarily configured by a plurality of wireless terminals perform peer-to-peer distributed network communication between wireless terminals belonging to each group, each group is encoded by an individual spreading code. When performing network communication by division multiplexing, host terminals in other groups periodically send busy codes when not performing communication in the group, and when a group attempts to start communication, A wireless network communication system characterized in that a terminal serving as a host of a group senses all spread codes for each code for a certain time and selects an unsensed code. 10. The wireless network communication system according to claim 9, wherein a busy code is periodically transmitted when each terminal in each group is not performing communication in the group. 11. In a wireless network communication system in which a plurality of groups arbitrarily configured by a plurality of wireless terminals perform peer-to-peer distributed network communication among wireless terminals belonging to each group, each group is encoded by an individual spreading code. A wireless network communication method characterized by starting communication with an arbitrary code when performing network communication by division multiplexing, and changing the code when it is determined that the same code as another group is used during communication. . 12. The wireless network communication system according to claim 11, wherein the code is changed when the throughput of intra-group communication falls below a certain threshold. 13. The wireless network communication system according to claim 11, wherein said code change is performed when the frequency of carrier sense during intra-group communication is equal to or higher than a certain threshold value. 14. The method according to claim 11, wherein the order of the code change is performed in an order determined for each group.
14. The wireless network communication system according to 2 or 13. 15. The wireless network communication method according to claim 11, wherein the order of the code change is randomly performed. 16. In a wireless network communication system in which a plurality of groups arbitrarily configured by a plurality of wireless terminals perform peer-to-peer distributed network communication among wireless terminals belonging to each group, each group is encoded by an individual spreading code. When performing network communication by division multiplex, when a certain group tries to start communication, a terminal serving as a host of the group first senses all spreading codes to be used, and another certain group is communicating. A wireless network communication system characterized by using the code to inquire about a code currently being used around the group, and selecting a used code from the information and the result sensed by the own station. 17. The wireless network communication system according to claim 16, wherein when there are a plurality of busy codes as a result of sensing all the codes, an inquiry is made with a code having the largest correlation value sensed.