JP2015162861A - Radio communication device and radio communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To switch a frequency band used between slave stations while maintaining star network topology centered around a master station for relaying communication between the slave stations in a communication system including a plurality of slave stations.SOLUTION: In a radio communication device 100, a discarding unit 181 discards a first switchover setting request for a use frequency band which request is transmitted from either one of a first communication device and a second communication device to the other, a relay requesting unit 182 transmits a relay request to request to relay a signal between the first communication device and the second communication device after switching the use frequency band to the first communication device and the second communication device if the first switchover setting request has been discarded, and a switchover requesting unit 183 transmits a second switchover setting request for the use frequency band to at least the communication device having transmitted the first changeover setting request.

Description

  The present invention relates to a radio communication apparatus and a radio communication method for performing frequency switching control for a plurality of radio frequency bands.

  Currently, in communication devices represented by, for example, netbooks, tablet terminals, mobile phone terminals, and the like, frequency bands of 2.4 GHz and 5 GHz (hereinafter “2.4 GHz band”, “5 GHz band”, or collectively “2. Wireless LAN (WLAN: Wireless Local Area Network) devices using a “4 GHz / 5 GHz band” are widely used. In particular, in recent years, with the increase in functionality of portable communication terminals (for example, smartphones or tablet terminals) and the improvement in image quality of video content, it is common practice for communication terminals to send and receive high-quality video files or large-capacity files. It has been broken. For this reason, communication terminals are required to communicate large-capacity files at high speed with a communication partner.

  As a high-speed wireless communication system, there is a standard that achieves a maximum throughput of 7 Gbps in a wireless LAN standard that uses a frequency band of 60 GHz typified by IEEE 802.11ad (hereinafter referred to as “60 GHz band”). IEEE 802.11ad has a significantly improved communication speed with respect to the existing wireless LAN standard using 2.4 GHz band / 5 GHz band, but has a short effective communication distance and is vulnerable to shielding. It has a feature that communication is easily interrupted. One of the techniques for overcoming the above characteristics is that the communication device controls the antenna directivity to improve the radio wave utilization efficiency in the direction of the communication partner.

  In addition, using a multiband wireless communication apparatus (also called a multiband station) that can use a plurality of frequency bands, in a 60 GHz band communicable area, communicate at an ultra high speed using the 60 GHz band, A method of performing communication using the 2.4 GHz band or the 5 GHz band is useful outside the communicable area of the 60 GHz band. In Patent Literature 1, when a multiband wireless communication apparatus uses a frequency band by switching, the multiband wireless communication apparatus exchanges information such as a frequency switching timing and a switching destination frequency band with a communication partner and performs a switching procedure. A fast session transfer (FST) method is disclosed.

JP 2012-10316 A

  In the prior art disclosed in Patent Document 1, peer-to-peer (P2P) communication is performed between communication terminals that switch the used frequency band by FST. On the other hand, a wireless LAN may adopt a configuration (star network topology) in which communication between slave stations (sometimes called stations) is relayed by a master station (sometimes called an access point).

  However, when the use frequency band is switched by FST when communication is performed between the slave stations via the master station, there is a problem that the network configuration becomes complicated.

  For example, when two or more slave stations relay 2.4 GHz band / 5 GHz band wireless LAN communication through the master station, when switching to the 60 GHz band by FST, these slave stations Without relaying, P2P communication between slave stations is started using the 60 GHz band.

  For this reason, as the number of slave stations increases, the network topology representing the connection relationship between the master station and each slave station device becomes more complicated. Specifically, it is a complex network topology in which a mesh network topology in which the slave stations communicate directly is complicated with a star network topology in which the slave stations relay communication between the slave stations. End up.

In order to establish communication with any slave station, all the slave stations must have at least the following requirements in an environment where such a complicated network topology is configured.
(1) The ability to use radios in different frequency bands simultaneously (2) The ability to control the antenna directivity in the 60 GHz frequency band for each different radio terminal

  However, since a slave station is generally required to be small and have low power consumption, it tends to be simplified as a wireless communication function. For this reason, it is very difficult for all the slave stations to satisfy the above requirements. In addition, there is a problem that communication itself cannot be established in a certain slave station if there are variations in the functions implemented in the slave station, such as a mixture of slave stations that meet the above requirements and slave stations that do not meet the above requirements. Can do.

  An object of the present invention is to establish a frequency band used between slave stations while maintaining a star-type network topology centering on the master station that relays communication between slave stations in a communication system having a plurality of slave stations. To provide a wireless communication device and a wireless communication method that can be switched.

  A wireless communication device according to one embodiment of the present invention relays a signal of communication between a first communication device and a second communication device that are devices that can directly communicate with each other by switching a plurality of frequency bands. And a MAC processing unit that performs processing in a MAC layer on the signal transmitted and received in the wireless unit, wherein the MAC processing unit includes the first communication device and the second communication. A discarding unit for discarding a first switching setting request for a used frequency band transmitted from any one of the devices to the other device; and when the first switching setting request is discarded, the first A relay request is transmitted to the communication device and the second communication device for requesting to relay a signal between the first communication device and the second communication device after switching the use frequency band. Relay request section to at least Against serial first transmission to a communication device switching setting request comprises a switch request unit for transmitting a second switch setting request used frequency band, and a configuration.

  A wireless communication method according to an aspect of the present invention relays a signal of communication between a first communication device and a second communication device that are devices capable of directly communicating with each other by switching a plurality of frequency bands. Then, processing in the MAC layer is performed on the signal to be transmitted / received, and in the processing of the MAC layer, transmission is performed from one of the first communication device and the second communication device to the other device. When the first switching setting request for the used frequency band is discarded and the first switching setting request is discarded, the used frequency band is set for the first communication device and the second communication device. A relay request for relaying a signal between the first communication device and the second communication device after switching, and at least for the communication device that transmitted the first switch setting request Use frequency band Transmitting a second switch setting request.

  According to the present invention, in a communication system having a plurality of slave stations, the frequency band used between the slave stations is maintained while maintaining a star-type network topology centering on the master station that relays communication between the slave stations. Can be switched.

Sequence diagram showing operation of frequency band switching between slave stations Sequence diagram showing frequency band switching operation between slave stations via the master station A diagram showing the network topology when communicating between slave stations via the master station Diagram showing network topology including direct communication between slave stations The figure which shows the antenna directivity pattern and signal arrival direction of a slave station 1 is a block diagram showing a configuration example of a wireless communication apparatus according to Embodiment 1 of the present invention. The block diagram which shows the internal structural example of the FST state management part which concerns on Embodiment 1 of this invention. Sequence diagram showing operation of frequency band switching according to Embodiment 1 of the present invention The figure which shows the network topology which concerns on Embodiment 1 of this invention. The figure which shows the antenna directivity pattern and signal arrival direction of the slave station according to Embodiment 1 of the present invention Sequence diagram showing operation of frequency band switching according to Embodiment 2 of the present invention Sequence diagram showing operation of frequency band switching according to the third embodiment of the present invention The figure which shows the network topology which concerns on Embodiment 3 of this invention.

  Hereinafter, a wireless communication system according to an embodiment of the present invention will be described with reference to the drawings. In each embodiment, the same components (sequences that perform the same operations) are denoted by the same reference numerals, and the description thereof is omitted because it is duplicated.

(Background to the contents of each embodiment of the present disclosure)
First, before describing each embodiment of the present disclosure, the above-described problem will be described in more detail.

  FIG. 1 is a basic sequence diagram showing a fast session transfer (FST) setting and switching procedure. In FIG. 1, as an example, a case where the use frequency band is switched from a state in which data is transmitted between the slave station 1 and the slave station 2 which are wireless stations using the 2.4 GHz band to the 60 GHz band will be described. To do.

  In FIG. 1, the slave station 1 and the slave station 2 perform data transmission 11 using the 2.4 GHz band. From this state, the switching setting sequence 12 is executed.

  In the switching setting sequence 12, the slave station 1 uses the 2.4 GHz band, which is the used frequency band before switching, to request a communication partner to set the switching of the used frequency band (FST Setup Request frame). Is transmitted to the slave station 2. The slave station 2 transmits a switching setting response frame (FST Setup Response frame) to the slave station 1 in response to the switching setting request frame. The switching setting request frame includes a state transition timer (STT) value (hereinafter simply referred to as “STT”) for controlling the state transition of the switching session. Each wireless station can return the state transition in the switching session to the initial state when the STT moves to 0. Further, the switching setting request frame includes a link loss timeout (LLT) value (hereinafter, simply referred to as “LLT”) for controlling the timing of executing switching. The slave station 1 and the slave station 2 switch the use frequency band to the 60 GHz band when a time corresponding to the LLT has elapsed as a time during which data transmission is not performed.

  After the use frequency is switched, a switching confirmation sequence 13 is executed.

  In the switching confirmation sequence 13, the slave station 1 uses a 60 GHz band, which is the used frequency band after switching, to send a switching confirmation request frame (FST acknowledgment Request frame) that requests the communication partner to confirm switching of the used frequency band. Transmit to station 2. Then, the slave station 2 transmits a switching confirmation response frame (FST acknowledgment Response frame) to the slave station 1 in response to the switching confirmation request frame. Thereby, the transition to the state where the data transmission 14 using the 60 GHz band between the slave station 1 and the slave station 2 is performed is completed.

  In FIG. 1, data transmission from the slave station 1 to the slave station 2 is shown in the data transmissions 11 and 14, but not limited thereto, transmission from the reverse direction (the slave station 2 to the slave station 1), or Bidirectional transmission may also be used.

  Here, the slave station 1 shown in FIG. 1 executes the switching setting sequence 12 for the slave station 2 when it is determined to switch the use frequency band from the 2.4 GHz band to the 60 GHz band. However, Patent Document 1 does not disclose a case where communication between the slave station 1 and the slave station 2 is relayed via the master station. Therefore, the operation of switching the used frequency band in a state where the master station relays communication between the slave station 1 and the slave station 2 will be described next.

  FIG. 2 is a basic sequence diagram showing a fast session transfer (FST) setting and switching procedure when the master station relays communication between the slave station 1 and the slave station 2. In FIG. 2, as an example, the case where the slave station 1 and the slave station 2 perform switching of the used frequency band from the state in which data transmission is performed using the 2.4 GHz band via the master station to the 60 GHz band. explain.

  In FIG. 2, the slave station 1 and the slave station 2 use the 2.4 GHz band to relay the master station and perform data transmission 15 and 16. From this state, switching setting sequences 17 and 18 are executed between the slave station 1 and the slave station 2 by relaying the master station. The operation in the switching setting sequences 17 and 18 is the same as the operation in the switching setting sequence 12 shown in FIG.

  After the frequency band switching is completed, the slave station 1 and the slave station 2 execute the switching confirmation sequence 13 by using 60 GHz that is the used frequency band after the switching. Thereby, the transition to the state where the data transmission 14 using the 60 GHz band between the slave station 1 and the slave station 2 is performed is completed.

  Here, as shown in FIG. 2, the communication between the slave station 1 and the slave station 2 (switching confirmation sequence 13 and data transmission 14) is not relayed through the master station after the switching of the used frequency band. It has become.

  FIG. 3 is a diagram showing a network topology in which the slave stations 1 to 4 communicate with each other by relaying the master station. Specifically, in FIG. 3, the slave station 1 and the slave station 2 use the 2.4 GHz band to relay the master station and perform data transmissions 15 and 16, and the slave station 2 and the slave station 3 use the 60 GHz band. The data transmissions 21 and 22 are performed by relaying the master station and the slave stations 2 and 4 perform data transmissions 16 and 23 by relaying the master station using the 2.4 GHz band.

  In FIG. 3, the master station is relayed for any communication, and it can be seen that a star-type network topology centered on the master station is configured.

  FIG. 4 is a diagram illustrating a network topology after the slave station 1 enters the 60 GHz band communication range by the movement 19 and the switching session of the used frequency band is executed in the communication between the slave station 1 and the slave station 2. FIG. 5 is a diagram showing an example of the directivity pattern of the 60 GHz band antenna in the slave station 2 shown in FIG.

  As shown in FIG. 4, after the execution of the switching session, the slave station 1 and the slave station 2 perform data transmission 14 by P2P communication using the 60 GHz band. In FIG. 4, the slave stations 2 and 3 perform data transmission 21 and 22 by relaying the master station using the 60 GHz band.

  As shown in FIG. 4, the communication between the slave station 2 and the slave station 3 is performed by relaying the master station, and the communication between the slave station 1 and the slave station 2 is directly performed between the slave stations. Therefore, in FIG. 4, it can be seen that the star-type network topology and the mesh-type network topology are mixed.

  At this time, as shown in FIG. 5, when the slave station 2 performs data transmission 22 with the slave station 3, the slave station 2 controls the antenna directivity 26 toward the master station and performs data transmission 14 with the slave station 1. When performing, it is necessary to control the antenna directivity 27 toward the slave station 1.

  Next, in FIG. 4, the slave station 4 further enters the 60 GHz band communication range by the movement 25, and after performing a use frequency switching session in the communication between the slave station 2 and the slave station 4, the slave station 4 uses the 60 GHz band. Assume that P2P communication is performed.

  Here, as in the slave station 2 shown in FIG. 5, as a wireless communication function provided in the slave station, the antenna directivity cover area (radiation angle; area indicated by a broken line or a solid line shown in FIG. 5) that can be controlled simultaneously There is a limit (for example, about 180 degrees in FIG. 5). For this reason, as shown in FIG. 5, since the slave station 2 controls the antenna directivities 26 and 27 with respect to the slave station 1 and the master station, the slave station 4 located in a direction substantially opposite to the slave station 1 is The antenna directivity is out of the controllable range. For this reason, an event in which the data transmission 24 using the 60 GHz band between the slave station 2 and the slave station 4 cannot be performed may occur.

  As described above, in a conventional switching session using FST, communication using the 60 GHz band is P2P communication, so that the network topology is complicated. Therefore, the requirements for controlling the antenna directivity of 60 GHz band and antenna directivity in each slave station are advanced, and there is a problem that 60 GHz band communication cannot be performed between slave stations that cannot cope with this requirement.

  Therefore, in the following embodiment, in view of the above-described problem of switching by FST, a method that can realize high-speed session switching while maintaining a star-type network topology in which a master station relays communication between slave stations will be described. To do.

(Embodiment 1)
The communication system according to the present embodiment employs a configuration having at least one wireless communication device (master station) and at least two communication terminals (slave stations).

  In the following description, the two slave stations have a function capable of directly communicating with each other by switching and using a plurality of frequency bands as described above.

[Configuration of Wireless Communication Device 100]
FIG. 6 is a block diagram showing a configuration of radio communication apparatus 100 according to the present embodiment. The wireless communication device 100 illustrated in FIG. 6 includes a 2.4 GHz / 5 GHz band wireless unit 101, a 60 GHz band wireless unit 102, and a MAC processing unit 103.

  The 2.4 GHz / 5 GHz band radio unit 101 performs radio processing on a communication signal using the 2.4 GHz band or the 5 GHz band. The 2.4 GHz / 5 GHz band radio unit 101 outputs a signal received via the antenna to the MAC processing unit 103 and transmits a signal received from the MAC processing unit 103 via the antenna. For example, the 2.4 GHz / 5 GHz band wireless unit 101 relays a communication signal between two communication apparatuses (slave stations) using the 2.4 GHz / 5 GHz band.

  The 60 GHz band wireless unit 102 performs wireless processing on a communication signal using the 60 GHz band. The 60 GHz band radio unit 102 outputs a signal received via the antenna to the MAC processing unit 103 and transmits a signal received from the MAC processing unit 103 via the antenna. For example, the 60 GHz band wireless unit 102 relays a communication signal between two slave stations using the 60 GHz band.

  The wireless communication apparatus 100 can perform wireless communication by switching between the 2.4 GHz / 5 GHz band and the 60 GHz band, and can also perform wireless communication using a plurality of frequency bands at the same time.

  The MAC processing unit 103 performs packet processing in a MAC (Media Access Control) layer on a signal transmitted / received in the 2.4 GHz / 5 GHz band radio unit 101 or the 60 GHz band radio unit 102. The MAC processing unit 103 exchanges data as a MAC frame with the 2.4 GHz / 5 GHz band wireless unit 101 and the 60 GHz band wireless unit 102.

  The MAC processing unit 103 includes a 2.4 GHz / 5 GHz wireless MAC frame processing unit 104, a 60 GHz wireless MAC frame processing unit 105, a frame buffer 106, a communication management unit 107, an FST state management unit 108, and a timer processing unit 109.

  The 2.4 GHz / 5 GHz wireless MAC frame processing unit 104 performs MAC frame processing on a communication signal using the 2.4 GHz / 5 GHz band. 2.4 GHz / 5 GHz wireless MAC frame processing unit 104 For MAC frame processing, for example, processing for converting a MAC frame into a physical layer signal for a signal to be transmitted received from an upper layer, or 2.4 GHz / 5 GHz band For example, a process of generating a MAC frame for a signal received from the wireless unit 101 can be given.

  The 60 GHz wireless MAC frame processing unit 105 performs MAC frame processing on a communication signal using the 60 GHz band. The MAC frame processing in the 60 GHz wireless MAC frame processing unit 105 includes, for example, processing for converting a MAC frame into a physical layer signal for a signal to be transmitted received from an upper layer, or received from the 60 GHz wireless unit 102 For example, a process of generating a MAC frame for the signal may be used.

  The frame buffer 106 stores the MAC frame, and exchanges the MAC frame with the 2.4 GHz / 5 GHz wireless MAC frame processing unit 104 or the 60 GHz wireless MAC frame processing unit 105. For example, the frame buffer 106 can also relay packets between radio processing units in different radio frequency bands of 2.4 GHz / 5 GHz band and 60 GHz band.

  The communication management unit 107 manages communication between the wireless communication device 100 and another device (slave station). For example, the communication management unit 107 controls the 2.4 GHz / 5 GHz wireless MAC frame processing unit 104, the 60 GHz wireless MAC frame processing unit 105, and the frame buffer 106, thereby transmitting data between the wireless communication device 100 and the slave station. Manage.

  For example, the FST state management unit 108 controls switching between slave stations by controlling the 2.4 GHz / 5 GHz wireless MAC frame processing unit 104, the 60 GHz wireless MAC frame processing unit 105, the frame buffer 106, and the timer processing unit 109. Manage sessions. For example, the FST state management 108 performs state management related to session switching with a slave station that is a plurality of communication partners of the wireless communication apparatus 100. Examples of the state related to session switching include an initial state of session switching by FST, a state where switching setting is completed, and a state where switching confirmation is completed.

  The timer processing unit 109 operates as a state transition timer (STT) or link loss timer (LLT) used for session switching. The timer processing unit 109 is used for switching session control in the FST state management unit 108.

  FIG. 7 is a block diagram illustrating an internal configuration of the FST state management unit 108 of the MAC processing unit 103. The component of the FST state management unit 108 shown in FIG. 7 receives the switching setting request frame transmitted from one communication device in the switching session of the used frequency band of the communication device among the operations of the FST state management unit 108. To a component (to be described later) until receiving a switching confirmation response frame. That is, the FST state management unit 108 performs not only the operation of the configuration unit shown in FIG.

  In FIG. 7, the discarding unit 181 transmits a use frequency band switching setting request frame transmitted from one of the slave stations using the 2.4 GHz / 5 GHz band or the 60 GHz band to the other apparatus. If received, the switch setting request frame is discarded. For example, the discarding unit 181 may discard the switching setting request frame by waiting for the elapse of a timeout period indicated in the switching setting request frame transmitted from the one device.

  When the switching setting request frame is discarded in the discarding unit 181, the relay requesting unit 182 includes a plurality of slave stations that are transmission / reception destinations of the switching setting request frame discarded in the discarding unit 181 (that is, switching targets of the used frequency band). In response to this, a relay request for relaying the signal between these slave stations after switching the used frequency band is transmitted. This relay request is, for example, an RDS (relay DMG STA: relay Directional Multigigabit Station) procedure in IEEE 802.11ad. This relay request is transmitted via a radio unit corresponding to the frequency band currently used with the plurality of slave stations.

  The switching request unit 183 requests switching to switch the usage frequency band to a plurality of slave stations that are transmission / reception destinations of the switching setting request frame discarded by the discarding unit 181 (that is, the switching target of the used frequency band). A setting request frame is transmitted. Note that the content of the switching setting request frame transmitted by the switching request unit 183 is the same as the content of the switching setting request frame discarded by the discarding unit 181. For example, the switching request unit 183 transmits the switching setting request frame after a predetermined time (STT) has elapsed since the switching setting request frame was discarded. The switching setting request frame is transmitted to the plurality of slave stations via a radio unit corresponding to the frequency band currently used.

  In addition, the switching request unit 183 transmits a used frequency band switching confirmation request frame to the slave station after the switching of the used frequency band by the switching setting request to the plurality of slave stations is completed from the wireless communication device 100. The switching confirmation request frame is transmitted via a radio unit corresponding to the frequency band after switching.

  Next, frequency band switching control in the above-described wireless communication apparatus 100 will be described in detail.

  FIG. 8 shows a basic procedure for setting and switching a high-speed session transfer (FST) when the master station (wireless communication apparatus 100) relays communication using the 2.4 GHz band between the slave station 1 and the slave station 2. FIG. In FIG. 8, as in FIG. 2, as an example, the slave station 1 and the slave station 2 relay the master station and perform data transmission using the 2.4 GHz band to use the frequency band from the 60 GHz band. A case where the switching is performed will be described.

  The slave station 1 and the slave station 2 perform data transmission 15 and 16 by relaying the master station. From this state, the switching setting discard sequence 31 is executed.

  In the switching setting discard sequence 31, the slave station 1 transmits a switching setting request frame for switching the use frequency band to the 60 GHz band as addressed to the slave station 2.

  On the other hand, when receiving the switching setting request frame transmitted from the slave station 1, the master station discards the switching setting request frame without transmitting it to the slave station 2.

  Further, when the switching setting discard sequence 31 is completed, the master station starts measuring time of an STT (state transition timer) 41.

  Next, in the packet relay procedure sequence 38, the master station requests the slave station 1 and the slave station 2 to request that the master station relay the communication between the slave stations after switching the used frequency band (after switching). Frequency band packet relay procedure).

  After the time corresponding to STT 41 has elapsed, the master station executes switching setting sequences 32 and 33 for the slave station 1 and the slave station 2. In the switch setting sequences 32 and 33, the master station transmits a switch setting request frame for requesting the slave station 1 and the slave station 2 to switch the use frequency band. The slave station 1 and the slave station 2 transmit a switch setting response frame to the master station in response to the switch setting request frame. For example, the contents of the switching setting request frame in the switching setting sequences 32 and 33 are the same as the contents of the switching setting request frame transmitted by the slave station 1 in the switching setting discard sequence 31. Similarly to FIG. 2, the switching setting request frame includes an LLT for controlling the timing for executing switching.

  The slave station 1 and the slave station 2 switch the use frequency band to the 60 GHz band when a time corresponding to the LLT has elapsed as a time during which data transmission is not performed. As shown in FIG. 8, by transmitting a switching setting request frame from the master station to both slave stations, the frequency band used between the slave station 1 and the master station after switching the used frequency band, The frequency band used between the station 2 and the master station is the same.

  After switching the use frequency band, the master station executes switching confirmation sequences 34 and 35, respectively. In the switching confirmation sequences 34 and 35, the master station transmits a switching confirmation request frame to the slave station 1 and the slave station 2 using the 60 GHz band that is the used frequency band after switching. Then, the slave station 1 and the slave station 2 transmit a switching confirmation response frame to the parent station in response to the switching confirmation request frame. This completes the transition to the state where data transmissions 36 and 37 using the 60 GHz band between the slave station 1 and the slave station 2 are performed.

  As described above, the master station, the slave station 1 and the slave station 2 use the 60 GHz band, which is the used frequency band after switching, in the packet relay procedure sequence 38, so that the master station relays communication between the slave stations. Has been completed. Therefore, after the switching of the used frequency band is completed, data transmissions 36 and 37 relaying the master station are performed between the slave station 1 and the slave station 2. That is, the slave station 1 and the slave station 2 do not communicate directly even after the switching of the used frequency band is completed.

  FIG. 9 is a diagram illustrating the network topology after the switching session illustrated in FIG. 8 is executed from the state of the network topology illustrated in FIG. For example, FIG. 9 is a diagram illustrating a network topology after the slave station 1 enters the 60 GHz band communication range by the movement 19 and executes a use frequency switching session in the communication between the slave station 1 and the slave station 2. FIG. 10 is a diagram showing an example of the directivity pattern of the 60 GHz band antenna in the slave station 2 shown in FIG.

  As shown in FIG. 9, after execution of the switching session, the slave station 1 and the slave station 2 perform data transmissions 36 and 37 by relaying the master station using the 60 GHz band. In FIG. 9, the slave station 2 and the slave station 3 perform data transmission 21 and 37 by relaying the master station using the 60 GHz band.

  Focusing on the slave station 2 communicating with a plurality of slave stations, the slave station 2 performs data transmission 37 with the master station both in communication with the slave station 1 and in communication with the slave station 3. That is, as shown in FIG. 9, it can be seen that a star-type network topology implemented by relaying the master station in any communication between the slave stations is formed.

  At this time, as shown in FIG. 10, even when the slave station 2 performs data transmission 37 of both the slave station 1 and the slave station 3, it is only necessary to control only the antenna directivity 26 toward the master station. Further, for example, even if the number of slave stations that communicate with the slave station 2 further increases from the state shown in FIG. 9 (not shown), Data transmission 37 with the station is performed. In other words, the slave station 2 does not need to control the antenna directivity in a plurality of directions even when communicating simultaneously with a plurality of different slave stations. For this reason, the power consumption in the slave station 2 can be reduced.

  As described above, in the switching session by FST according to the present embodiment, communication using the 60 GHz band is performed by relaying the master station, so that the network topology remains a star type. Therefore, the requirements for controlling the antenna directivity in 60 GHz band and antenna directivity in each slave station are simplified, and by satisfying the requirements in the slave stations, the slave stations that cannot perform 60 GHz band communication can be reduced. .

  Therefore, according to the present embodiment, in a communication system having a plurality of slave stations, it is used between slave stations while maintaining a star-type network topology centering on the master station that relays communication between slave stations. Frequency band can be switched.

(Embodiment 2)
In the present embodiment, a case will be described in which switching of the used frequency is rejected from one slave station in the switching setting sequence.

  The wireless communication apparatus according to the present embodiment has the same basic configuration as that of wireless communication apparatus 100 according to Embodiment 1, and will be described with reference to FIG.

  FIG. 11 shows a basic procedure for setting and switching a high-speed session transfer (FST) when the master station (wireless communication apparatus 100) relays communication using the 2.4 GHz band between the slave station 1 and the slave station 2. FIG. In FIG. 11, the same reference numerals are given to sequences in which the same processing as that in the first embodiment (FIG. 8) is performed, and the description thereof is omitted.

  As shown in FIG. 11, between the slave station 1 and the slave station 2, data transmissions 15 and 16 using the 2.4 GHz band relaying the master station (wireless communication apparatus 100) are performed.

  In FIG. 11, after the time corresponding to STT 41 has elapsed, the master station executes switching setting sequences 32 and 51 for the slave station 1 and the slave station 2. In the switch setting sequence 32, as in the first embodiment, the master station transmits a switch setting request frame to the slave station 1, and the slave station 1 transmits a switch setting response frame to the master station. Then, the slave station 1 switches the use frequency band to the 60 GHz band when the time corresponding to the LLT has elapsed as the time when data transmission is not performed (frequency switching with the slave station 1 is completed).

  On the other hand, in the switching setting sequence 51, the master station transmits a switching setting request frame to the child station 2, as in the switching setting sequence 33 in the first embodiment. On the other hand, the slave station 2 transmits a switching setting rejection frame to the parent station as a response to the switching setting request frame in order to reject switching of the used frequency band. That is, the slave station 2 continues to use the 2.4 GHz band.

  When the master station (FST state management unit 108) receives the switching setting rejection frame from the slave station 2, the master station (FST state management unit 108) executes the switch deletion sequence 52 after the slave station 1 completes the frequency switching to the 60 GHz band. In the switching deletion sequence 52, the master station transmits a switching deletion frame to the slave station 1. When the slave station 1 receives the switching deletion frame from the master station, the slave station 1 returns the used frequency band to the 2.4 GHz band. That is, the slave station 1 deletes the frequency band switching process to the 60 GHz band (frequency switching deletion with the slave station 1 is completed).

  When the frequency switching deletion at the slave station 1 is completed, the data transmissions 15 and 16 relaying the master station are resumed between the slave station 1 and the slave station 2 using the 2.4 GHz band.

  As described above, in this embodiment, when the master station (wireless communication apparatus 100) rejects switching of the used frequency band from the slave station 2 in response to the switch setting request frame transmitted by the master station, the slave station 1 ( A switching deletion frame for requesting deletion of switching of the used frequency band by the switching setting request frame transmitted by the parent station is transmitted to the slave station that has requested switching of the used frequency band.

  In this way, even if one of the slave stations rejects the use frequency band switching setting request, the use frequency band of the other slave station is returned to the use frequency band before switching (the frequency switching process is deleted). ) And communication between slave stations can be resumed.

(Embodiment 3)
In the present embodiment, a case will be described in which the switching setting sequence is executed for only one slave station in the switching setting sequence.

  The wireless communication apparatus according to the present embodiment has the same basic configuration as that of wireless communication apparatus 100 according to Embodiment 1, and will be described with reference to FIG.

  FIG. 12 is a basic sequence showing a high-speed session transfer (FST) setting and switching procedure when the master station (wireless communication apparatus 100) relays communication using the 60 GHz band between the slave station 1 and the slave station 2. FIG. In FIG. 12, the same reference numerals are given to sequences in which the same processes as those in the first embodiment (FIG. 8) or the second embodiment (FIG. 11) are performed, and the description thereof is omitted.

  FIG. 13 is a diagram showing a network topology after the switching control shown in FIG. 12 is executed.

  For example, as shown in FIG. 13, the switching session shown in FIG. 12 is out of the range of 60 GHz band communication due to the movement 19 of the slave station 1, whereas the master station and the slave station 2 are within the range of 60 GHz band communication. It is executed when it is located in succession.

  As shown in FIG. 12, the slave station 1 and the slave station 2 perform data transmissions 36 and 37 using the 60 GHz band by relaying the master station (wireless communication apparatus 100).

  In FIG. 12, after the elapse of STT 41, the master station executes a switching setting sequence 32 for the slave station 1. On the other hand, the master station does not execute the switching setting sequence for the slave station 2. That is, the master station transmits the switch setting request frame only to the slave station 1 that has transmitted the switch setting request frame.

  In the switch setting sequence 32, as in the first embodiment, the master station transmits a switch setting request frame to the slave station 1, and the slave station 1 transmits a switch setting response frame to the master station. Then, the slave station 1 switches the use frequency band to the 2.4 GHz band when the time corresponding to the LLT has elapsed as the time when data transmission is not performed (frequency switching with the slave station 1 is completed).

  The master station (FST state management unit 108) executes the same switching confirmation sequence 34 as that of the first embodiment only for the slave station 1 after the slave station 1 completes the frequency switching to the 2.4 GHz band. . Thereby, the transition to the state where the data transmission 15 using the 2.4 GHz band between the slave station 1 and the master station is performed is completed.

  On the other hand, the slave station 2 continues to use the 60 GHz band because the switching setting sequence is not performed.

  Therefore, after the use frequency switching of the slave station 1 is completed, in the communication between the slave station 1 and the slave station 2, the data transmission 15 using the 2.4 GHz band is started between the slave station 1 and the master station. The data transmission 37 using 60 GHz is resumed between the slave station 2 and the master station.

  That is, as shown in FIG. 13, when the slave station 1 moves out of the 60 GHz band communication due to the movement 19, the slave station 1 performs data transmission 15 using the 2.4 GHz band in communication with the master station. The slave station 2 performs data transmission 37 using the 60 GHz band in communication with the master station. In this way, the slave station 2 performs data transmission without switching the use frequency band with the master station even when the use frequency band of the slave station 1 is switched.

  Therefore, also in the present embodiment, as shown in FIG. 13, it can be seen that communication between any slave stations is performed by relaying the master station to form a star-type network topology. Therefore, the slave station 2 only needs to control the antenna directivity 26 in the direction of the master station even when performing data transmission 37 with both the slave station 1 and the slave station 3 in the same manner as in FIG. There is no need to control the antenna directivity in a plurality of directions. For this reason, as in the first embodiment, the power consumption in the slave station 2 can be reduced.

  Therefore, according to the present embodiment, as in the first embodiment, in a communication system having a plurality of slave stations, a star-type network topology centering on the master station that relays communication between the slave stations is maintained. The frequency band used between the slave stations can be switched.

  Further, according to the present embodiment, as shown in FIG. 13, the slave station 2 can maintain the data transmission 37 using the 60 GHz band even when the use frequency band of the slave station 1 that is the communication partner is switched. As a result, the slave station 2 can continue to perform high-speed transmission.

  The embodiments of the present invention have been described above.

  In the above embodiment, the case where the 2.4 GHz / 5 GHz band and the 60 GHz band are used as the radio frequency band used has been described. However, the radio frequency band to be used is not limited to these, and a plurality of different radio frequency bands may be used.

  Further, the operation of radio communication apparatus 100 according to the above-described embodiment can be realized by software in cooperation with hardware.

  Each processing unit of radio communication apparatus 100 according to the above embodiment is a functional block for explaining the concept of the function, and is configured using hardware, for example, an integrated circuit, or having a processor and a memory The function may be realized by executing predetermined software in step (b). It should be noted that the present invention is not necessarily configured as illustrated, and may have other configurations that realize equivalent functions.

  The present disclosure has the effect of realizing the switching of the frequency band to be used at high speed, and has high compatibility with the network environment of the wireless LAN constructed in the star type, so that the frequency switching control can be easily introduced. . For example, it is useful as a frequency band switching control method for switching a frequency band to be used in a wireless communication device or the like that supports multiband, and a wireless communication apparatus using the same.

100 Wireless communication device 101 2.4 GHz / 5 GHz band wireless unit 102 60 GHz band wireless unit 103 MAC processing unit 104 2.4 GHz / 5 GHz wireless MAC frame processing unit 105 60 GHz wireless MAC frame processing unit 106 Frame buffer 107 Communication management unit 108 FST state Management unit 109 Timer processing unit 181 Discarding unit 182 Relay request unit 183 Switching request unit

Claims (7)

A wireless unit that relays signals of communication between the first communication device and the second communication device, which are devices capable of directly communicating with each other by switching between a plurality of frequency bands;
A MAC processing unit that performs processing in a MAC layer on the signal transmitted and received in the wireless unit;
Comprising
The MAC processing unit
A discarding unit for discarding the first switching setting request for the used frequency band, which is transmitted from one of the first communication device and the second communication device to the other device;
When the first switching setting request is discarded, the first communication device and the second communication device after switching the used frequency band with respect to the first communication device and the second communication device. A relay request unit for transmitting a relay request for relaying a signal between
A switching request unit that transmits a second switching setting request for a used frequency band to at least the communication device that has transmitted the first switching setting request;
Wireless communication device. The switching request unit transmits the second switching setting request to both the first communication device and the second communication device,
A frequency band used between the first communication device and the wireless communication device, and a frequency band used between the second communication device and the wireless communication device after switching the use frequency band; , Are the same,
The wireless communication apparatus according to claim 1. The switch request unit transmits the second switch setting request only to the communication device that has transmitted the first switch setting request,
A frequency band used between the first communication device and the wireless communication device, and a frequency band used between the second communication device and the wireless communication device after switching the use frequency band; Is different,
The wireless communication apparatus according to claim 1. The discard unit discards the first switch setting request by waiting for the elapse of a timeout period indicated in the first switch setting request;
The wireless communication apparatus according to claim 1. The switching request unit transmits a usage frequency band switching confirmation request to the communication apparatus that has transmitted the at least the first switching setting request after switching the used frequency band by the second switching setting request.
The wireless communication apparatus according to claim 1. When the switching request unit is rejected from the other device for switching the use frequency band in response to the second switching setting request, the switching request unit uses the second device according to the second switching setting request. Request deletion of frequency band switching,
The wireless communication apparatus according to claim 2. Relaying signals for communication between the first communication device and the second communication device, which are devices capable of directly communicating with each other by switching between a plurality of frequency bands,
Performs processing in the MAC layer for the signal transmitted and received
In the processing of the MAC layer,
Discarding the first switching setting request of the used frequency band transmitted from one of the first communication device and the second communication device to the other device;
When the first switching setting request is discarded, the first communication device and the second communication device after switching the used frequency band with respect to the first communication device and the second communication device. Send a relay request to relay the signal between
Transmitting a second switching setting request for a used frequency band to at least the communication device that has transmitted the first switching setting request;
Wireless communication method.

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