JP2014057358A - Radio device and communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily expand an area connectable to a network.SOLUTION: A radio device, connected to a first radio device to configure a first network, includes communication means for receiving a first synchronous signal from the first radio device and for transmitting a second synchronous signal, generated based on the first synchronous signal, to a second area at least including other than the first area receivable of the first synchronous signal transmitted from the first radio device. The radio device waits for the reception of a connection request frame destined to the radio device after the transmission of the second synchronous signal and during a period designated from the first radio device. On receiving the connection request frame destined to the radio device, the radio device discriminates to permit or not to permit the connection request, on the basis of a communication band use condition allocated from the first radio device.

Description

  The present invention relates to wireless communication.

A technology has been proposed in which a terminal that detects interference from another logical network becomes a base station of a logical network that integrates a logical network to which the terminal itself is connected and another logical network, and expands a communication area (for example, a patent). Reference 1). However, in the technique disclosed in Patent Document 1, it is complicated to set which terminal is to be a base station of the logical network after integration, and a function in which each terminal connected to each logical network can be a base station. Must have.

In addition, there is a technology in which a terminal that has moved out of the wireless communication area of the wireless base station relays data from the base station to other terminals that are within the wireless communication area, thereby substantially expanding the communication area. Proposed. However, the technique disclosed in Patent Document 2 does not consider the case where the terminal to be relayed is in the power save mode, the directionality is directed to the base station, and the like. In addition, the setting of the base station and the relay terminal becomes complicated.

JP 2006-135943 A JP 2008-271523 A

The present invention has been made in view of the above, and an object of the present invention is to provide a radio apparatus and method capable of easily expanding an area connectable to a network.

A wireless device according to an embodiment is a wireless device that is connected to a first wireless device and forms a first network, receives a first synchronization signal from the first wireless device, and transmits the first wireless device Communication means for transmitting a second synchronization signal generated based on the first synchronization signal to a second region including at least other than the first region capable of receiving the first synchronization signal; After transmission of the second synchronization signal, when waiting for reception of a connection request frame addressed to the wireless device for a specified period from the first wireless device, and receiving a connection request frame addressed to the wireless device, It is determined whether or not to permit a connection request based on the usage status of the communication band assigned by the first wireless device.

  According to the present invention, the area connectable to the network can be easily expanded.

1 is a diagram showing a wireless system according to a first embodiment of the present invention. 1 is a block diagram showing a configuration of a wireless device according to a first embodiment of the present invention. The figure which shows the transmission timing of a synchronizing signal. The sequence diagram which shows operation | movement of the radio system which concerns on the 1st Embodiment of this invention. The figure which shows the radio | wireless system which concerns on the modification 5 of the 1st Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described. The wireless LAN standard IEEE802.11 will be described as an example. However, the wireless LAN standard is not limited to the IEEE802.11 standard wireless communication system, and can be applied to all wireless communication systems. The MAC layer access control method will be described by taking a polling method, which is a centralized control method, as an example. However, the MAC layer access control method can be applied to other general wireless communication methods such as a typical CSMA / CA method. A wireless base station (access point) is referred to as AP, and a wireless device and a wireless terminal are referred to as STA.

(First embodiment)
FIG. 1 is a diagram illustrating a wireless system according to the first embodiment. A dotted circle indicates an area (hereinafter referred to as a communication area) in which radio waves transmitted by a wireless device existing at the center of the circle can be received.
In the example of FIG. 1, each radio apparatus has radio wave directivity in all directions, but may be in a specific direction.

The wireless system includes a parent AP1, STA1, STA2, STA3, child AP1, and S
TAa, STAb, and STAx. Parent AP1 and STA1-3 and child AP1 and ST
Aa and b are a single network (for example, BSS: Basic Service).
Set). The parent AP1 is directly connected to the STA1 to STA3 and the child AP1. STA1 ~
3 communicate with each other via the parent AP1. The child AP1 is directly connected to the STAa and b. S
TAa and b communicate with each other via the child AP1. STAa, b are child AP1 and parent A
It communicates with STA1-3 via P1. STAx does not belong to any network. The radio waves transmitted by the STAx can be received only by the STA1, and the parent AP1 cannot.

FIG. 2 is a block diagram showing a configuration of the radio apparatus STA1 according to the first embodiment. The configurations of STA2, STA3, and child AP1 are the same.

The STA 1 includes a transmission / reception unit 10, a communication control unit 20, a mode switching unit 30, and a child AP function unit 4.
0 and a synchronization signal storage unit 50.

The transmission / reception unit 10 transmits and receives wireless signals. The transmission / reception unit 10 controls directivity when transmitting and receiving a radio signal. The transceiver 10 transmits radio waves in a specific direction or all directions. The transmission / reception unit 10 receives radio waves from a specific direction or all directions.

  The communication control unit 20 controls the overall communication, for example, the transmission / reception unit 10.

The child AP function unit 40 performs processing related to the function of the child AP. A child AP refers to a wireless device that operates as an AP of a certain terminal (for example, STAx) and operates as an STA of a certain base station (for example, parent AP1). The parent AP has a function of accommodating the child AP as described above as an STA, and has a function of controlling all terminals connected to the STA and subordinates of the child AP.

The synchronization signal storage unit 50 stores information described in the synchronization signal from the parent AP1. The synchronization signal is a signal (for example, a Beacon signal) that is periodically transmitted by an access point (for example, the parent AP1) for synchronization.

The mode switching unit 30 switches whether to operate in a mode of a terminal connected to an access point (parent AP1 or the like) or a child AP that accommodates a station (STAx or the like).

The configuration of the parent AP1 is the same as that of the STA1 except that the parent AP function unit 40 is provided instead of the child AP function unit 40. The parent AP function unit performs processing related to the function of the parent AP. The parent AP function unit performs allocation processing of information on a number of connected STAs including STAs under the control of the child AP and a scheduling period for each STA, holds and manages the allocated information, and transmits and receives based on the scheduling information Instructions etc. are performed.

FIG. 3 is a diagram illustrating an example of the operation of the wireless system according to the first embodiment. FIG. 4 is a sequence diagram illustrating an operation of the wireless system according to the first embodiment. In the method shown in FIG.
The STAx is connected to the STA1 and is accommodated in the parent AP1 network.

First, the parent AP 1 and the STAs 1 to 3 configure the same network and are in a state where they can communicate with each other. The parent AP 1 selects a terminal (hereinafter, cell edge terminal) located at the end of the communication area of the parent AP 1 among the STAs 1 to 3 and the child AP 1 that are directly connected. The parent AP 1 selects a terminal whose radio wave reception intensity is equal to or less than a threshold value as a cell edge terminal. The parent AP1 notifies the cell edge terminal (STA1) that it has been selected as a cell edge terminal, and transmits a cell edge notification signal instructing to perform a synchronization signal transfer process.

The parent AP 1 periodically transmits a synchronization signal. The parent AP1 includes, in the synchronization signal, a flag indicating that transfer processing is required for the cell edge terminal (hereinafter referred to as a transfer flag), a period for transferring the synchronization signal (hereinafter referred to as a transfer period), and a connection to the parent AP1. A period of waiting for a connection request signal for requesting (for example, Association Request) is described. The parent AP1 transmits a synchronization signal into the network (step S10).
1). Since the parent AP 1 cannot communicate at least during the “transfer period” and the “standby period”, it enters a power save mode (at least a mode in which power supply to the transmission / reception unit 10 is stopped), thereby reducing power consumption. . During the “waiting period”, when the parent AP 1 also waits for reception of a connection request signal, it may be activated.

The STAs 1 to 3 receive the synchronization signal from the parent AP 1 (step S102). STA2
Since 3 is not a cell edge terminal, the synchronization signal transfer process is not performed. The STA1 performs a synchronization signal transfer process. Note that the STA1 does not have to transfer the synchronization signal when the remaining battery level is equal to or less than the threshold value. At this time, the STA1 informs the parent AP1 that the transfer of the synchronization signal is rejected.
May be notified.

When the transfer flag is described in the synchronization signal, the communication control unit 20 of the STA1 stores the information described in the synchronization signal in the synchronization signal storage unit 50 and creates a synchronization signal that describes the MAC address of the STA1. .

Next, the communication control unit 20 of the STA1 transmits a synchronization signal during the “transfer period” (step S103). The communication control unit 20 of the STA1 transmits a synchronization signal to an area including at least the communication area of the parent AP1. The communication control unit 20 of the STA1 transmits radio waves in all directions (omni) when transmitting the synchronization signal. The communication control unit 20 of the STA1 may direct the radio wave directivity in a direction different from the direction of the parent AP1. And the communication control part 20 of STA1
After transferring the synchronization signal, it waits for reception of the connection request signal in the “waiting period”. Note that if the connection request signal is not received during the “waiting period”, the STA1 again returns to the parent A
The directivity of transmission / reception is directed to P1, and the normal communication state is restored. However, the directivity of transmission / reception does not necessarily have to be directed to the parent AP1.

The STAx starts scanning for a synchronization signal to connect to the AP, such as when the power is turned on (step S104). When STA1 transfers a synchronization signal during the period when STAx is scanning, STAx receives the synchronization signal (step S105). STAx
Understands that the synchronization signal from the parent AP1 has been transferred by the STA1 from the information described in the synchronization signal.

Next, the STAx determines whether or not to request accommodation of the parent AP1 by the network based on the information described in the synchronization signal (step S106). STAx is the parent AP
If a list of addresses of terminals connected to one network is described, whether or not to request accommodation by the parent AP1 network depending on whether or not the list includes addresses of terminals desired to be connected May be determined. STAx determines whether or not to request accommodation by the parent AP1 network according to the presence / absence of connection to the external network when the synchronization signal includes the presence / absence of connection to the external network such as the Internet. May be. The STAx may determine whether to request accommodation of the parent AP1 by the network based on whether or not the reception power of the synchronization signal is equal to or greater than a threshold value.

If it is determined to connect to the parent AP1 network, the STAx transmits a connection request signal to the STA1 during the “waiting period” described in the synchronization signal (step S107). In the connection request frame, information such as the number of applications executed by the STAx and the bandwidth amount requested by the applications may be described together.

The STA1 receives a connection request signal from the STAx (step S108). When the communication control unit 20 of the STA1 receives a connection request signal from the STAx during the “waiting period”, the communication control unit 20
It is determined whether or not the TAx connection is permitted (step S109). The communication control unit 20 of the STA1 may permit the connection if the remaining bandwidth amount allocated from the parent AP1 is greater than or equal to the bandwidth amount necessary for the STAx (application executed by the STAx). ST
The communication control unit 20 of A1 may determine whether or not to permit connection of the STAx depending on whether or not the remaining battery level is equal to or greater than a threshold value. The communication control unit 20 of the STA1 may take a form in which the STA1 itself uses the bandwidth amount allocated from the parent AP1 and newly requests the parent AP1 for the bandwidth amount necessary for the STAx.

If it is determined that the STAx connection is permitted, the communication control unit 20 of the STA1 acquires a transmission right by a poll frame or the like from the parent AP1, and the switching signal for notifying that the STA1 becomes a child AP and connects to the STAx, and the STAx Is sent to the parent AP 1 (step S110). The parent AP 1 is in the power save mode during the “transfer period” and the “waiting period”, but after the “waiting period”, it becomes the normal mode and grants a transmission right to the STA 1 to cause the STA 1 to transmit the accommodation request signal. .

The parent AP1 receives the switching signal and the accommodation request signal from the STA1 (step S111).
). Whether or not the parent AP1 accommodates the STAx (the STA1 is switched to the child AP and the STAx
Whether or not to be connected) is determined (step S112). The parent AP 1 may determine whether or not to accommodate the STAx according to the remaining number of connectable terminals from the number of connected terminals in the current network. Based on the bandwidth amount allocated to the connected terminal, the parent AP 1 may further determine whether or not to accommodate the STAx by comparing the allocatable bandwidth amount with the bandwidth amount requested by the STAx. . When it is determined that the STAx is accommodated, the parent AP 1 transmits an accommodation permission signal for accommodating the STAx to the STA 1 (step S113).

The STA1 receives the accommodation permission signal from the parent AP1 (step S114). When receiving the accommodation permission signal, the mode switching unit 30 of the STA1 switches from the terminal mode to the child AP mode (step S115). The mode switching unit 30 of the STA1 activates the child AP function unit 40,
The processing for the function of the child AP is started. After starting the processing for the function of the child AP, S
The TA1 communication control unit 20 transmits a connection permission signal to the STAx (step S11).
6). The STAx receives a connection permission signal from the child AP (STA1) (step S117).
). The STAx determines that the STA1 has changed to the child AP mode from the connection permission signal, and that the STAx
I know that I was connected to 1. After this, the STAx has a child AP (STA1) and a parent AP1.
It is possible to communicate with the STAs 1 to 3 through the network.

Through the above operation, a terminal located outside the communication area of the parent AP1 can be accommodated in the parent AP1 network, and the area connectable to the parent AP1 network can be easily expanded. By making a cell edge terminal a candidate for a child AP, an STA suitable for expanding the area connectable to the network of the parent AP 1 can be easily selected. By determining whether or not the cell edge terminal becomes a child AP depending on whether the remaining battery level of the cell edge terminal is equal to or greater than the threshold, it is possible to connect to the network of the parent AP1 based on a period during which communication can be continued. The area can be enlarged.

In FIG. 4, the parent AP 1 selects and designates the cell edge terminal before transferring the synchronization signal. However, a field (hereinafter referred to as a cell edge field) in which the address of the cell edge terminal is described in the synchronization signal. The MAC address of the cell edge terminal may be described in the synchronization signal (step S101) provided by the parent AP1. The parent AP1 may transmit the synchronization signal by sequentially describing the addresses of the terminals connected to the parent AP1 in the cell edge field. In addition, all terminals transmit a synchronization signal without providing a cell edge field, and by providing a transfer request bit in the synchronization signal and setting the corresponding bit when transmitting the synchronization signal to be transferred, the synchronization signal is transmitted to all terminals. You may take the method of instructing transfer. By doing so, it is possible to expand the area connectable to the network of the parent AP 1 while omitting the process of selecting the cell edge terminal.

Next, details of the operation of STAx in steps S104 and S105 will be described.
The STAx is turned on and activated by a user or a timer of the device. STAx
Can be entered by the user after startup or read from memory etc.
And security key information are set.

Next, the STAx scans (searches) for a network having an SSID that matches the set SSID (step S104). When receiving from the AP a synchronization signal in which the SSID that matches the set SSID is received, the STAx transmits the A that is the source of the synchronization signal.
Connection processing with P is performed. When the synchronization signal is not received from the AP but the synchronization signal transferred by the STA1 is received (step S105), the STAx transmits a connection request to the STA1 and requests whether the parent AP1 is accommodated by the network. (Step S1
06). If you can not receive the sync signal at all even after scanning a predetermined number of times,
STAx becomes an AP and starts a network.

Next, details of the operation of STA1 in steps S102 and S103 will be described.
First, the transmission / reception unit 10 of the STA1 receives a cell edge notification signal from the parent AP1. S
Upon receipt of the cell edge notification signal, the TA1 communication control unit 20 functions as a cell edge terminal (function to transfer a synchronization signal, function to store synchronization signal information in the synchronization signal storage unit 50).
Enable

Next, the transmission / reception unit 10 of the STA1 receives a synchronization signal from the parent AP1 (step S10).
2). The communication control unit 20 of the STA1 confirms that the transfer flag is described in the synchronization signal, and writes the information described in the synchronization signal in the synchronization signal storage unit 50. The communication control unit 20 of the STA1 acquires information indicating the “transfer period” and the “standby period” described in the synchronization signal. The “transfer period” and the “waiting period” are specified by a relative value from the time when reception of the synchronization signal is completed, or an absolute value of time information for performing synchronization processing with the parent AP 1 using the synchronization signal. The communication control unit 20 of the STA1 starts a timer from the time when reception of the synchronization signal is completed.

At the timing when the “transfer period” starts, the communication control unit 20 of the STA1 sends a synchronization signal that describes the information stored in the synchronization signal storage unit 50 and the address of the STA1 to all directions in which the STA1 can transmit. (For example, omni), transmission of the synchronization signal is started (step S
103).

At the timing when the “waiting period” starts, the communication control unit 20 of the STA1 sets the direction (directivity) to receive radio waves as all directions (for example, omni) that the STA1 can receive from the direction of the parent AP1. Start waiting for a connection request signal.

If the connection request signal is not received even though the “waiting period” has ended, STA1
The communication control unit 20 changes the direction (directivity) for receiving radio waves from all directions that the STA1 can receive to the direction of the parent AP1. Note that the communication control unit 20 of the STA1 may continue the omni transmission / reception.

(Modification 1)
In the first embodiment, the only terminal that can communicate with the STAx is the STA1. However, there may be a plurality of terminals (here, STA1 and STA2 as an example) that can communicate with the STAx, such as when the STAx is located slightly above the position shown in FIG.
Here, the parent AP1 selects STA1 and STA2 as cell edge terminals, and STA1
Assume that a cell edge notification signal is transmitted to STA2 and STA2.

When the transfer flag is described in the synchronization signal, the parent AP1 transmits, in addition to the “waiting period”, the “transfer period for STA1”, which is the period during which STA1 transmits the synchronization signal, and STA2 transmits the synchronization signal. The “transfer period for STA2”, which is a period to be performed, is described. “STA1
The “transfer period for STA” and the “transfer period for STA2” do not overlap.

In this way, STA1 can change the synchronization signal describing the address of STA1 to “STA”.
STA2 transmits a synchronization signal that describes the address of STA2
A transmission period for A2 "is transmitted, and mutual collision can be avoided.

In addition, when transmission of the synchronization signal from STA1 and STA2 can be separated in space in consideration of directional transmission or terminal arrangement, the “transfer period for STA1” and the “transfer period for STA2” are the same. It may be.

The STAx receives from the STA1 and STA2 a synchronization signal in which each address is described (step S105). The STAx transmits a connection request signal to the higher reception power of the synchronization signal (step S107). Note that STAx is STA
1 and STA2 may be inquired about the remaining battery level and connected to the battery with the higher remaining battery level. In addition, when the synchronization signals transmitted from a plurality of terminals are each equal to or greater than the threshold value, the STAx may inquire about the remaining battery power of the plurality of terminals and connect to the battery with the larger remaining battery capacity.

In this way, a terminal having a communication quality with a STAx newly connected to the network of the parent AP1 that is higher than a certain level and having a large remaining battery capacity and a period of time during which communication can be continued can be designated as a child AP. Can be selected as a terminal.

(Modification 2)
In Modification 1 of the first embodiment, when there are a plurality of terminals (here, STA1 and STA2 as examples) that can communicate with STAx, STA1 and STA2 assign their addresses to the synchronization signal. The synchronization signal is transmitted (transferred) as described (step S1).
03).

However, in the first modification of the first embodiment, the STA1 and the STA2 can transmit (transfer) exactly the same synchronization signal (for example, the synchronization signal itself received from the parent AP1) (step S103).

When the parent AP1 describes the transfer flag in the synchronization signal, in addition to the “waiting period”,
“Transfer timing”, which is the timing at which STA1 and STA2 transmit a synchronization signal, is described.

When the plurality of cell edge terminals (STA1, STA2) receive the synchronization signal in which the transfer flag is described, they simultaneously transmit the synchronization signal itself received from the parent AP1 at the “transfer timing” (step S103).

When STAx receives synchronization signals from a plurality of cell edge terminals (STA1, STA2) at the same time, the synchronization signal transmitted from STA1 and the synchronization signal transmitted from STA2 are exactly the same. The reception characteristic can be improved by the diversity effect in which the signals strengthen each other.

When the STAx requests connection to the network of the parent AP1, the STAx transmits a connection request signal with the parent AP1 as the destination (step S107). The STA1 and STA2 receive the connection request signal transmitted from the STAx to the parent AP1 although the destination address is not their own address (step S108).

Then, STA1 and STA2 individually determine whether or not to accommodate STAx (step S109). If only one side determines to accommodate the STAx, then the same processing as in the first embodiment is performed. If STA1 and STA2 determine that STAx is accommodated, one of STA1 and STA2 that has acquired the transmission right earlier is the parent A
A switching signal and an accommodation request signal are transmitted to P1 (step S110). STA1 and STA2
The other one that has acquired the transmission right earlier interrupts the STAx accommodation process (the process after step S110) when the switching signal and the accommodation request signal are transmitted from the STA1 to the parent AP1.

In this way, the synchronization signal from the parent AP1 can be transmitted over a wider range using the diversity effect, and the tolerance against errors in the synchronization signal can be improved.

(Modification 3)
In the second modification of the first embodiment, only the terminal designated as the cell edge terminal for the parent AP1 transmits (transfers) the synchronization signal (step S103).

However, in the second modification of the first embodiment, all of the terminals (STA1 to 3 and child AP1) that are connected to the parent AP1 and directly receive the synchronization signal from the parent AP1 (hereinafter, all terminals) Transmit exactly the same synchronization signal (for example, the synchronization signal itself received from the parent AP1) (
Transfer) (step S103). Note that all terminals connected to the parent AP1 may be determined in advance to transfer the synchronization signal, or the parent AP1 may transmit a cell edge notification signal in which all terminals are cell edge terminals.

When the parent AP1 describes the transfer flag in the synchronization signal, in addition to the “waiting period”,
“Transfer timing”, which is a timing at which all terminals transmit a synchronization signal, is described.

When all the terminals have received the synchronization signal in which the transfer flag is described, they simultaneously transmit the synchronization signal itself received from the parent AP 1 at “transfer timing” (step S103). In addition,
The STAx can receive the synchronization signal transmitted from the STA1 and STA2 among all terminals. The STAx cannot receive the synchronization signal transmitted from the STA3 and the child AP1 among all the terminals.

In the case of STAx, when synchronization signals are simultaneously received from a plurality of terminals (STA1, STA2) among all terminals, the synchronization signal transmitted from STA1 and the synchronization signal transmitted from STA2 are exactly the same. The reception characteristic can be improved by the diversity effect in which both synchronization signals strengthen each other.

The STAx receives the synchronization signal whose transmission source is the parent AP1 from the STA1 and STA2 (step S105). When the STAx requests connection of the parent AP1 to the network (step S106), the STAx transmits a connection request signal to the parent AP1.

All terminals (here, STA1 and STA2 in particular) try to receive (observe) a connection request signal destined for the parent AP1 and its delivery confirmation signal (for example, Ack). All terminals can grasp that the parent AP1 has accepted the connection request when the connection request signal addressed to the parent AP1 and the delivery confirmation signal thereof can be received. On the other hand, when all terminals can receive a connection request signal destined for the parent AP1 a plurality of times and cannot receive the delivery confirmation signal at all, and when the number of retransmissions of the connection request signal exceeds a threshold value Changes to the parent AP1 and transmits a delivery confirmation signal for the connection request signal destined for the parent AP1 to the STAx.
Thereafter, as in the second modification of the first embodiment, STA1 performs processing (steps S109 and S11).
0).

In this way, even if the parent AP1 does not select a cell edge terminal, a terminal located outside the communication area of the parent AP1 can be accommodated in the parent AP1 network, and an area that can be connected to the parent AP1 network is established. Can be easily expanded.

(Modification 4)
In the first embodiment, when the cell edge terminal (STA1) transmits (transfers) the synchronization signal (step S103), it is assumed that the STAx is being scanned (step S104). However, there are cases where the STAx is not yet powered on and has not started scanning.

In this case, the STA1 transmits a synchronization signal (step S103), and then does not receive a connection request signal from the STAx even if it waits for a “waiting period” and a connection request signal.

However, it is assumed that a predetermined period has passed and STA1 has received a search signal (Probe Request) for searching for an AP connected from STAx. In this case, ST
The communication control unit 20 of A1 uses the information stored in the synchronization signal storage unit 50 to
1 is generated and transmitted to STAx when STA1 acquires the transmission right. Thereafter, processing similar to that of the first embodiment (step S109 and subsequent steps) is performed.

By doing so, even if the STAx is not scanning during the “transfer period”, the area that can be connected to the network of the parent AP 1 can be easily expanded by transmitting the search signal.

(Modification 5)
In the first embodiment, an example has been described in which the parent AP1, STA1, STA2, and STAx can transmit (omni) radio waves in all directions. However, parent AP1, STA1, STA2, ST
Ax transmits radio waves in all directions (omni), and radio waves from all directions (omni)
It does not have to be received.

  FIG. 5 is a diagram illustrating an arrangement of the parent AP1, STA1, STA2, and STAx.

The parent AP1, STA1, and STA2 receive radio waves from a specific direction and transmit radio waves in the specific direction. The parent AP1, STA1, and STA2 can narrow the directivity of transmission and reception radio waves with respect to at least one of areas (sectors) obtained by dividing a specific direction into four. When the parent AP1 directs directivity to the first sector, if the STA2 directs directivity to the fourth sector, communication can be performed between the parent AP1 and the STA2. However, when the parent AP1 directs directivity to the first sector, if the STA2 directs directivity to the first to third sectors, communication cannot be performed between the parent AP1 and the STA2. When the parent AP1 directs directivity toward the fourth sector, if the STA1 directs directivity toward the first sector, communication can be performed between the parent AP1 and the STA2. However, when the parent AP1 directs directivity to the fourth sector, if the STA1 directs directivity to the second to fourth sectors, communication cannot be performed between the parent AP1 and the STA1. When the parent AP1 directs directivity to the second and third sectors, STA1,
Cannot communicate with STA2. If STA1 transmits radio waves with directivity directed to at least the third sector, STAx can receive radio waves.

As shown in FIG. 5, even if the parent AP1, STA1, STA2, and STAx are arranged and the transmission and reception range is limited, the method described in the first embodiment and the first to third modifications of the first embodiment is used. The area connectable to the parent AP1 network can be easily expanded.

The parent AP1 selects the wireless terminals (STA1, STA2) that communicate with the end sectors (1, 4th sector) among the 1st to 4th sectors as cell edge terminals. The parent AP1 is 1 to
Among the fourth sectors, even a wireless terminal that communicates in the central sector (second and third sectors) selects a terminal whose signal received power is equal to or less than a threshold value as a cell edge terminal. Note that the communication control unit 20 of the parent AP1 manages each terminal and its directivity information, uses the fourth sector for transmission / reception with the STA1, and uses the first sector for communication with the STA2. I manage things.

STA1 and STA2 can determine whether they are cell edge terminals without receiving a cell edge notification signal from parent AP1. The AP periodically transmits synchronization signals while sequentially directing the directivity of radio waves to the first to fourth sectors that can be transmitted. This synchronization signal describes the number of wireless directional sectors of the parent AP 1 and the sector number used for transmission. Therefore, if the STA1 and the STA2 receive the synchronization signal from the parent AP1, the STA1 and the STA2 can grasp the number of wireless directional sectors of the connected parent AP1 and the number of sectors that can be received by the STA1 and STA2. STA1 and STA2 determine that they are cell edge terminals when they are located in the end sector of the parent AP1 sectors.

Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

STA1, STA2, STA3, STAx ... wireless device AP1 ... wireless base station 10 ... transmission / reception unit 20 ... communication control unit 30 ... mode switching unit 40 ... child AP function unit 50 ...・ Sync signal storage

Claims (12)

A wireless device connected to the first wireless device and constituting a first network,
The first synchronization signal received from the first wireless device and transmitted by the first wireless device
Communication means for transmitting a second synchronization signal generated based on the first synchronization signal to a second region including at least the first region other than the first region capable of receiving the synchronization signal;
Waiting for reception of a connection request frame addressed to the wireless device for a specified period from the first wireless device after transmission of the second synchronization signal,
A wireless device that, when receiving a connection request frame addressed to the wireless device, determines whether or not to permit a connection request based on a use state of a communication band allocated from the first wireless device. The wireless device according to claim 1, wherein when the connection request is permitted, a connection permission frame is transmitted to a transmission source wireless device of a connection request frame addressed to the wireless device, and the transmission source wireless device is accommodated in the first network. . The first synchronization signal transmitted from the first wireless device includes not only the wireless device but also the second
It is also received by the wireless device,
The time when the wireless device transmits the second synchronization signal is designated as the first time from the first wireless device,
A time at which the second wireless device transmits a third synchronization signal generated based on the first synchronization signal is designated as a second time from the first wireless device,
The first time and the second time are different,
The radio apparatus according to claim 1, wherein the communication unit transmits the second synchronization signal at the first time. It further comprises control means for controlling the directivity of radio waves to be transmitted and received,
When the communication unit waits for reception of the connection request frame, the control unit sets the directivity of the radio wave in all directions or different from the directivity to the first wireless device. 4. The wireless device according to any one of 3. The wireless device according to claim 1, further comprising an antenna that is connected to the communication unit and transmits and receives radio waves. A communication means for receiving the synchronization signal;
The transmission source wireless device of the synchronization signal connects to the first wireless device to form a first network, and the period during which a connection request frame can be transmitted is grasped from the synchronization signal, and is connected to the first network. Control means for determining whether or not,
A wireless device that transmits a connection request frame to the transmission source wireless device during a period in which the communication means can transmit the connection request frame when it is determined that the connection is made to the first network. The wireless device according to claim 6, wherein the communication unit communicates within the first network after receiving a connection permission frame from a transmission source wireless device of the synchronization signal. The radio apparatus according to claim 6 or 7, further comprising an antenna connected to the communication means for transmitting and receiving radio waves. The radio apparatus according to claim 1, wherein the first network is a BSS (Basic Service Set). A communication method of a wireless device that connects to a first wireless device and constitutes a first network,
The first synchronization signal received from the first wireless device and transmitted by the first wireless device
A second synchronization signal generated based on the first synchronization signal is transmitted to a second region including at least other than the first region capable of receiving the synchronization signal;
Waiting for reception of a connection request frame addressed to the wireless device for a specified period from the first wireless device after transmission of the second synchronization signal,
A wireless device communication method for determining whether or not to permit a connection request based on a use state of a communication band allocated from the first wireless device when a connection request frame addressed to the wireless device is received. A wireless device communication method comprising:
Receive sync signal,
The transmission source wireless device of the synchronization signal connects to the first wireless device to form a first network, and the period during which a connection request frame can be transmitted is grasped from the synchronization signal, and is connected to the first network. Whether or not
A wireless device communication method in which, when it is determined to connect to the first network, the communication unit transmits a connection request frame to the transmission source wireless device during a period in which the connection request frame can be transmitted. The communication method according to claim 10 or 11, wherein the first network is a BSS (Basic Service Set).