WO2018105397A1

WO2018105397A1 - Wireless communication method and wireless communication device

Info

Publication number: WO2018105397A1
Application number: PCT/JP2017/041973
Authority: WO
Inventors: ヤオハンガイアスウィー; レイホァン; 裕幸本塚; 誠隆入江
Original assignee: パナソニックインテレクチュアルプロパティコーポレーションオブアメリカ
Priority date: 2016-12-05
Filing date: 2017-11-22
Publication date: 2018-06-14
Also published as: TW201826734A; TWI741083B

Abstract

A wireless communication device that: transmits a beacon frame during a beacon transmission interval (BTI); receives a transmission sector sweep (SSW) frame from another wireless communication device during a beamforming training (BFT) interval after the BTI and, when discovery request information is included in the transmission SSW frame, extracts, from the transmission SSW frame, information about a first transmission sector selected by the other wireless communication device, and selects a second transmission sector from the transmission sectors used by the other wireless communication device and included in the transmission SSW frame; uses the first transmission sector to transmit a feedback frame that included information pertaining to the selected second transmission sector, during a BFT interval; and uses the first transmission sector to transmit a probe response frame that includes information about the selected second transmission sector, during a data transmission interval after the BFT interval.

Description

Wireless communication method and wireless communication apparatus

The present disclosure relates to a wireless communication method and a wireless communication device.

IEEE 802.11 is one of the wireless LAN related standards, and includes, for example, the IEEE802.11ad standard (hereinafter referred to as “11ad standard”) (for example, see Non-Patent Document 1).

The beam forming (BF) technology is used in the 11ad standard. Beamforming refers to changing the directivity of one or more antennas of a transmitter and a receiver included in a wireless communication device, and setting the antenna directivity so that the communication quality, for example, reception intensity is optimized. This is a communication method.

When the conventional STA (Station) does not complete the beam forming in the active scan, the STA (Station) retries the beam forming, for example, in DTI (Data Transmission Interval). In this case, the time until the STA completes discovery of AP / PCP (Access Point / Personal basic service set Control Point) is delayed. In addition, it interferes with other STAs that perform data communication.

One aspect of the present disclosure is to provide a wireless communication method and a wireless communication device that reduce a delay in time until discovery is completed.

A wireless communication method according to an aspect of the present disclosure is a wireless communication method of a wireless communication device, transmitting one or more beacon frames in a beacon transmission period, and in a beamforming training period after the beacon transmission period, When one or more transmission sector sweep frames are received from another wireless communication device, and the one or more transmission sector sweep frames include information on a discovery request, the other ones from the one or more transmission sector sweep frames Information on the first transmission sector selected by the wireless communication device is extracted, and the second transmission sector is selected from the transmission sectors used by the other wireless communication device included in the received one or more transmission sector sweep frames. In the beamforming training period, select the selected second A feedback frame including information on a transmission sector is transmitted using the first transmission sector, and a probe response frame including information on the selected second transmission sector is transmitted in a data transmission period after the beamforming training period. Transmission is performed using the first transmission sector.

Note that these comprehensive or specific modes may be realized by a system, apparatus, method, integrated circuit, computer program, or recording medium, and the system, apparatus, method, integrated circuit, computer program, and recording medium. It may be realized by any combination of the above.

According to one aspect of the present disclosure, it is possible to reduce a delay in time until discovery is completed.

Further advantages and effects of one aspect of the present disclosure will become apparent from the specification and drawings. Such advantages and / or effects are provided by some embodiments and features described in the description and drawings, respectively, but all need to be provided in order to obtain one or more identical features. There is no.

Block diagram showing an example where an STA performs an active scan and discovers another STA The figure which shows an example of the procedure in which STA performs an active scan The figure explaining the procedure in which STA performs an active scan regarding Embodiment 1. The figure which shows an example of a format of the SSW frame containing the field (DR = 1) which shows a discovery request | requirement The figure which shows an example of the format of the Probe response which AP / PCP transmits in DTI The figure which shows an example of the procedure which STA performs an active scan in the same BI as BI (beacon interval) which STA is performing an active scan A flowchart showing an example of a procedure in which a STA performs discovery for an AP / PCP Block diagram showing an example of the configuration of a communication device Detailed block diagram showing an example of the configuration of a MAC processor The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of a format of a DMG beacon The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of the format of a SSW frame The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of the format of a SSW frame The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of the format of a SSW frame The figure which shows another example of the format of a SSW frame The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of the format of Short SSW packet The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of the format of Short SSW packet The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of a format of a SSW-FB frame The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of the format of a Probe response The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The block diagram which shows an example of a structure of a communication apparatus (AP / PCP and STA) The figure which shows an example of the procedure which STA performs an active scan with respect to AP / PCP regarding Embodiment 2. The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. Flow chart showing an example of a procedure for performing discovery by the STA The figure which shows an example of the procedure which STA performs an active scan with respect to AP / PCP regarding Embodiment 3. A flowchart showing an example of a procedure in which a STA performs discovery by an active scan of Discovery Mode = 1 The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of a format of a DMG beacon The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of the procedure in which STA performs an active scan with respect to AP / PCP. The figure which shows an example of the procedure which STA performs an active scan with respect to AP / PCP regarding Embodiment 4. The figure which shows an example of a format of a DMG beacon The figure which shows another example of the format of a DMG beacon Flow chart showing an example of a procedure for performing discovery by the STA The figure which shows an example of the procedure which STA performs a discovery The figure which shows an example of the procedure which STA performs an active scan with respect to AP / PCP regarding Embodiment 5. The figure which shows an example of a format of Short SSW packet containing shortened information about BSS A flowchart showing an example of a procedure in which a STA performs discovery by an active scan of Discovery Mode = 1 The block diagram which shows an example of a structure of a communication apparatus (AP / PCP and STA) The figure which shows an example of the procedure in which STA performs an active scan Flow chart showing an example of a procedure for performing discovery by the STA

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

It should be noted that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the claimed subject matter.

A procedure for finding another STA in order for an STA, which is an example of a wireless communication device, to perform initial connection with another STA is called discovery. As an application using 60 GHz millimeter wave communication, for example, data download in an automatic ticket gate requiring high-speed connection, a backup wireless line that replaces and / or complements a wired network in a data center, and the like can be considered. Since such applications require high-speed connections, for example, high-speed discovery of 100 msec or less is being studied.

IEEE802.11ad, which is a 60 GHz millimeter wave communication standard, defines active scan as a discovery procedure. The active scan includes BTI (BeaconeaTransmission Interval) processing, A-BFT (Association-BeamForming Training) period processing, and Probe exchange processing procedures.

FIG. 1 shows an example of a block diagram when the STA 100 performs an active scan and discovers another STA (PEER STA). Note that there may be other STAs (STAs 200) that perform active scanning coexist. PEER STA may be an AP or PCP (represented as “AP / PCP”), which is an example of a radio base station (wireless communication device). Further, the STA 100 and the STA 200 may be non-AP / PCP STAs (slave devices, terminals: wireless communication devices). In order to simplify the description, the wireless communication device is described as a wireless base station and a slave (terminal), but the wireless base station may operate as a slave, and the slave is also a wireless base station. It may work.

In BTI, the STA 100 receives or transmits a transmission sector sweep using a DMG (Directional Multi-Gigabit) beacon frame (hereinafter also referred to as “DMG beacon”).

The AP / PCP 300 transmits a plurality of DMG beacons while switching transmission sectors (transmission beams). The STA 100 receives the DMG beacon and measures reception strength and / or reception quality. Note that the STA 100 that performs active scanning may perform a transmission sector sweep in the BTI.

In the A-BFT period, the STA 100 transmits or receives a transmission sector sweep (of the STA 100) using an SSW (Sector SWeep) frame. The STA 100 receives or transmits an SSW feedback (SSW-FB) frame.

The STA 100 switches the transmission sector (transmission beam) for each SSW frame and transmits the SSW frame. AP / PCP 300 receives the SSW frame, measures the reception strength and / or reception quality, and transmits the SSW-FB frame including the measurement result to STA 100. The STA 100 receives the SSW-FB frame and completes the BFT. When the STA 100 performs transmission sector sweep in BTI, the AP / PCP 300 performs transmission sector sweep in the A-BFT period, and the STA 100 transmits the SSW-FB frame.

As the BFT, the STA 100 that performs the active scan determines a transmission best sector (a beam suitable for transmission) in the BTI and A-BFT periods. The beam indicates the antenna directivity. When the BFT is completed, the STA 100 transmits a Probe request frame (hereinafter may be simply expressed as “Probe request”) in the Probe exchange process. When the AP / PCP 300 receives the Probe request, the AP / PCP 300 transmits a Probe response frame (hereinafter simply referred to as “Probe response”).

If BFT is not performed, the STA 100 performs omni-directional communication. However, since the propagation loss is large in 60 GHz millimeter-wave communication, it may be difficult to make an omnidirectional transmission signal reach the AP / PCP 300.

The STA 100 acquires information related to the connection destination terminal (for example, the AP / PCP 300) and the BSS (Basic Service Set) by the Probe exchange process. The STA 100 determines a connection destination according to the acquired information. For example, the STA 100 determines whether to connect to the AP / PCP 300 or to discover another terminal.

Here, in the 11ad standard, the A-BFT period is shared with other STAs that have received the DMG beacon.

FIG. 2 is a diagram illustrating an example of a procedure in which the STA 100 and the STA 200 perform an active scan. In FIG. 2, the BI (beacon interval) includes a BTI, an A-BFT period, and a DTI (Data TransferInterval). For example, the STA 100 and the STA 200 receive a DMG beacon (“DBcn” in the drawing) in the BTI, and perform a transmission sector sweep (transmission of an SSW frame) in the A-BFT period.

In the A-BFT period, when a plurality of STAs perform transmission sector sweeps and contention (for example, collision of transmission packets) occurs, there is at most one STA that receives the SSW-FB frame and completes the BFT. There is. In FIG. 2, the STA 100 receives the SSW-FB frame transmitted from the AP / PCP 300 to the STA 100, and the STA 200 does not receive the SSW-FB frame.

Thereby, the STA 100 performs Probe exchange processing (processing from sending a Probe request to receiving a Probe response) in the DTI. The AP / PCP 300 transmits an ACK frame when the received Probe request does not include an error. Whether or not an error is included in the Probe request may be determined by, for example, FCS (Frame Check Sequence) and / or CRC (Cyclic Redundancy Check). The description of ACK is omitted.

STA (STA 200) that has not completed BFT may wait for the next BTI (not shown) and retry BFT. However, in this case, since the processing delay reaches at least one beacon interval (for example, 100 msec), the delay is large.

Note that the STA 200 may start a sector sweep in the DTI. For example, a STA 200 that has not completed beamforming in the BTI and A-BFT periods (eg, failed due to contention) may perform BFT in the DTI after the A-BFT period.

However, in DTI, there is interference on the radio channel (due to sector sweep by other STA not shown, data transmission / reception by STA 100), and the probability of completing BFT may be low.

(Embodiment 1)
In the first embodiment, the STA that performs the active scan transmits a field indicating the discovery request (DR = 1) set in the SSW frame, and supports reception of a Probe response including beamforming feedback information. Notice.

As a result, in the A-BFT period and DTI, even when other STAs that perform active scanning compete with the sector sweep, the STA that transmits the SSW frame including DR = 1 completes the beamforming by receiving the Probe response. Can be judged. Therefore, the probability that beam forming is completed is increased, and the time required for discovery is shortened.

The procedure for the STA 100 to perform an active scan will be described with reference to FIG.

In the BTI of FIG. 3, for example, the AP / PCP 300 changes the transmission sector for each DMG beacon (DBcn), and transmits the DMG beacon.

In the BTI of FIG. 3, the STA 100 receives a DMG beacon. Note that another STA (STA 200) may receive the DMG beacon in the same BTI.

In the A-BFT period of FIG. 3, the STA 100 changes the transmission sector for each SSW frame including a field (DR = 1) indicating a discovery request, and transmits the SSW frame.

FIG. 4 is a diagram illustrating an example of a format of an SSW frame including a field (DR = 1) indicating a discovery request. The SSW frame includes a Frame Control field, a Duration (frame length) field, an RA (Receive (r) Address: reception address) field, a TA (Transmit (ter) Address: transmission address) field, and an SSW (sector sweep). Field, SSW Feedback (SSW-FB) field, FCS (Frame Check Sequence) field.

The SSW field contains information on sector sweep. For example, when the STA 100 changes the transmission sector for each SSW frame and transmits the SSW frame, the information on the sector sweep is the transmission sector ID.

The SSW-FB field includes a Sector Select (sector selection) subfield, a DMG Antenna Select (DMG antenna selection) subfield, an SNR Report (SNR: signal to noise ratio report) field, a Poll Required (polling request) subfield, and a Discovery Request. (Discovery request, described as DR) includes a subfield and a reserved subfield.

When the SSW frame of 11ad standard (not shown) is transmitted during the A-BFT period, the SSW-FB field includes a 7-bit Reserved subfield, whereas the SSW frame of FIG. -The FB field contains a 6-bit reserved subfield and a 1-bit Discovery Request (discovery request) subfield.

The sector selection subfield includes a sector ID (first transmission sector) included in the DMG beacon determined as the best quality among the DMG beacons received by the STA 100 during the BTI. The AP / PCP 300 may determine the sector ID of the best sector by receiving the SSW frame and obtaining the value of the sector selection subfield.

The discovery request subfield is used to request the Probe response including the beamforming feedback information to the AP / PCP 300. That is, the discovery request subfield is used to notify AP / PCP 300 that it corresponds to reception of a Probe response frame including beamforming feedback information.

In the A-BFT period of FIG. 3, the AP / PCP 300 receives one or more SSW frames.

The AP / PCP 300 determines the transmission sector ID in the SSW frame with good reception quality among the received SSW frames as the best sector of the transmission source STA (second transmission sector). In FIG. 4, the transmission sector ID is included in the sector selection subfield of the SSW feedback field.

The AP / PCP 300 includes the best sector information in the SSW-FB frame and transmits it to the STA 100. The STA 100 receives the SSW-FB frame.

Note that the STA 100 fails to receive the SSW-FB frame by not detecting a preamble due to, for example, an FCS error due to noise and / or contention with other STA transmission not shown (referred to as a reception error). ) There are cases.

Note that the STA 100 does not need to transmit an ACK frame even when it receives an SSW-FB frame. Therefore, it is unknown for the AP / PCP 300 whether or not the STA 100 has received the SSW-FB frame in the A-BFT period. When AP / PCP 300 receives an SSW frame including DR = 1 in A-BFT, AP / PCP 300 transmits a Probe response including beamforming feedback to STA 100 in DTI.

FIG. 5 is a diagram illustrating an example of a format of a Probe response transmitted by the AP / PCP in the DTI.

5 The format of the Probe response in FIG.

The Probe response includes a Frame Body (Probe Response frame body) part. Unlike the frame response body of the 11ad standard, the frame response body of the Probe response in FIG. 5 includes a Beamforming response element.

The Beamforming Feedback element includes an Element ID (element ID) field, a Length field, an Element 、 ID Extension (element ID extension) field, and an SSW Feedback (SSW-FB) field.

The element ID field may be used in determining the type of an element (for example, each element of Timestamp, SSID, Beamforming Feedback, Vendor Specific) included in the Probe Response frame body. The value of the element ID field is defined in the 11ad standard for each element type. An element ID that is not used in the 11ad standard, such as “222”, may be assigned to the element ID for determining the Beamforming Feedback element.

The Length field indicates the length of the remaining part of the Beamforming Feedback in octets. For example, the number of octets (3 or 4) obtained by combining the element ID extension field (0 or 1 octet) and the SSW Feedback field (3 octets) is set as the value of the Length field.

The element ID extension field may be used instead of the element ID field in order to determine the type of element. When an element ID that is not used in the 11ad standard is assigned to an element ID that discriminates a BeamformingbackFeedback element, the element ID extension field may not be used and the length may be 0 octets.

The SSW Feedback field is the same as the 11ad standard SSW-FB field. That is, this is the same as when the DiscoveryDisRequest field is set to Reserved in the SSW Feedback field of FIG.

The AP / PCP 300 transmits the SSW-FB field of the Probe response shown in FIG. 5 including the best sector of the STA 100. Therefore, the STA 100 can obtain information on the best sector even when an SSW-FB frame reception error occurs. Further, the probe response frame information includes information on AP / PCP (for example, Capability information: information on supported modulation schemes and transmission rates) and BSS information (for example, available radio bandwidth). Therefore, the STA 100 can complete the active scan even when an SSW-FB frame reception error occurs in the A-BFT period.

Further, the STA 100 may omit the transmission of the Probe request (see FIG. 3) to reduce the delay.

In the DTI of FIG. 3, the STA 100 receives a Probe response including beamforming feedback (Beamforming エレメント Feedback element), and performs communication with the AP / PCP 300 based on information included in the beamforming feedback (for example, the value of the Sector Select field). Determine the best sector to use. Also, since the Probe response from the AP / PCP 300 has been received, the discovery by the active scan procedure for the AP / PCP 300 is completed (success).

The STA 100 may execute the following when the discovered AP / PCP is determined as the connection destination after the active scan (additional discovery for other AP / PCP may be performed) is completed. That is, the STA 100 may set the transmission antenna to the best sector determined in the discovery and transmit the association request frame to the AP / PCP.

Note that, even when the AP / PCP 300 transmits the SSW-FB frame to the STA 100 during the A-BFT period, the AP / PCP 300 may transmit a Probe response including beamforming feedback in the DTI. The STA 100 may receive a Probe response including beamforming feedback in the DTI even when a reception error occurs in the reception of the SSW-FB frame.

Thereby, for example, the STA 100 can avoid retrying beam forming (SSW transmission) during DTI. Therefore, the delay required for discovery can be shortened.

In addition, the STA 100 can receive a Probe response without transmitting a Probe request in DTI. Therefore, the delay required for discovery can be shortened.

FIG. 6 is a diagram illustrating an example of a procedure in which the STA 200 performs an active scan in the same BI (BI beacon interval) that the STA 100 is performing an active scan. Note that the description of the same processing as in FIG. 3 in the STA 100 and the AP / PCP 300 is omitted. Also, the description of the case where the STA 200 performs the same process as the STA 100 of FIG. 3 is omitted.

<Processing with BTI>
The STA 200 receives the DMG beacon in the BTI. In addition, when the location of STA100 and STA200 and / or the direction of an antenna differ, the best sector of STA100 and the best sector of STA200 differ. For this reason, each reception quality of the DMG beacon received by the STA 100 is different from each reception quality of the DMG beacon received by the STA 200.

<Processing with A-BFT>
The STA 200 transmits the SSW frame including DR = 1 in the A-BFT period (similar to the STA 100 in FIG. 3).

AP / PCP 300 receives an SSW frame including DR = 1 in the A-BFT period. The SSW frame transmitted by the STA 100 and the SSW frame transmitted by the STA 200 may be synchronized in transmission timing. Since the STA 100 and the STA 200 have different locations, antenna directions, and / or antenna directivities, the SSW frame transmitted by the STA 100 is AP even if the SSW frames are transmitted at the same time (for example, the same transmission slot). / PCP300 may be reached (received), and the SSW frame transmitted by the STA 200 may not reach the AP / PCP300 (not received) (first SSW frame in FIG. 6).

In addition, the SSW frames transmitted by the STA 100 and the STA 200 reach the AP / PCP 300 and interfere with each other (referred to as collision or contention), and the AP / PCP 300 may not receive any SSW frame (the second one in FIG. 6). SSW frame).

In addition, the SSW frame transmitted by the STA 200 may reach (receive) the AP / PCP 300, and the SSW frame transmitted by the STA 100 may not reach (receive) the AP / PCP 300 (the third SSW frame in FIG. 6). ).

In the A-BFT, the AP / PCP 300 uses the transmission sector ID (included in the SSW field in FIG. 4) in the SSW frame with good reception quality among the one or more received SSW frames. Decide on the best sector.

The AP / PCP 300 may determine the best sector for each transmission source STA when one or more received SSW frames include a plurality of transmission source STAs.

The AP / PCP 300 transmits an SSW-FB frame according to the received SSW frame in the A-BFT period. For example, the AP / PCP 300 may use the transmission source (transmission source STA) of the received SSW frame as the transmission destination of the SSW-FB frame. Further, the AP / PCP 300 may include the sector ID of the best sector of the transmission source STA determined in the A-BFT period processing in the SSW-FB frame.

The AP / PCP 300 may select one of the transmission source STAs and transmit the SSW-FB frame when a plurality of transmission source STAs are included in the plurality of SSW frames received during the A-BFT period.

The AP / PCP 300 may select one STA that is the transmission source of the SSW frame having the best reception quality (regardless of the transmission source STA), and may transmit the SSW-FB frame. Even when the A-BFT contention occurs, the STA can receive the SSW-FB frame to know the best sector and exchange the probe.

The AP / PCP 300 may select a transmission source STA that does not include DR = 1 in the SSW frame and transmit the SSW-FB frame. Since STAs including DR = 1 can receive a Probe response later, priority is given to STAs not including DR = 1. Thereby, both STAs can perform Probe exchange (reception of Probe response) with a short delay.

In the A-BFT period of FIG. 6, the AP / PCP 300 transmits the SSW-FB frame to the STA 100 and does not transmit the SSW-FB frame to the STA 200.

<Processing with DTI>
In the DTI, the AP / PCP 300 includes the best sector of the STA 200 in the SSW-FB field of the Probe response in FIG. 5 and transmits the Probe response. As a result, the STA 200 can obtain information on the best sector without receiving the SSW-FB frame in the A-BFT period.

Further, since the Probe Response Frame includes information about the AP / PCP 300 (for example, Capability Information: including information on supported modulation schemes and transmission rates) and BSS information (for example, available wireless bandwidth), The STA 200 can complete the active scan without receiving the SSW-FB frame in the A-BFT.

Further, the STA 200 may reduce the delay by omitting the transmission of the Probe request (see FIG. 2) in the DTI.

The AP / PCP 300 may acquire TXOP (Tx Opportunity: transmission opportunity) for transmitting a plurality of frames in response to transmission of a Probe response addressed to the STA 100 and the STA 200 in the DTI. Compared with the case where each STA acquires a TXOP for transmitting a Probe request as shown in FIG. 2, TXOPs can be secured in a lump, so that transmission can be made more efficient.

The

STAs

100 and 200 receive the Probe response from the AP / PCP 300, and complete (success) discovery by the active scan procedure for the AP / PCP 300.

FIG. 7 is a flowchart illustrating an example of a procedure in which the STA 100 performs discovery with respect to the AP / PCP 300.

First, the STA 100 starts discovery (S001).

Next, the STA 100 receives a DMG beacon in BTI (S002). The DMG beacon may be transmitted for the AP / PCP 300 to perform a sector sweep. That is, the AP / PCP 300 may switch the transmission direction of the radio signal by switching the transmission sector, and may transmit one or more DMG beacons. The AP / PCP 300 may transmit an information element and a field indicating that A-BFT is scheduled after BTI in a DMG beacon.

Next, when the A-BFT period is not scheduled (S003: NO), the flow returns to S002 in order for the STA 100 to wait for the next BTI.

When the A-BFT period is scheduled (S003: YES), the STA 100 transmits an SSW frame including DR = 1 in the A-BFT period with the AP / PCP 300 as a transmission destination (S004). Note that the STA 100 may transmit an SSW frame in order to perform sector sweep. That is, the STA 100 may switch the transmission direction of the radio signal by switching the transmission sector and transmit one or more SSW frames. This corresponds to the STA 100 performing a sector sweep in response to the sector sweep using the DMG beacon by the AP / PCP 300, and is called a responder BFT. The STA 100 determines the best sector of the AP / PCP 300 based on the reception quality of the DMG beacon received in the BTI, and transmits the best sector information (for example, sector ID) in the SSW frame during the A-BFT period. Also good.

If the AP / PCP 300 does not receive the SSW frame of S004 in the A-BFT period (S005: NO), the flow does not transmit the SSW-FB frame (and the Probe response of S012) to the STA 100, and the flow proceeds to S002. Return. Note that the case where the SSW frame is not received may include a case where there is a reception error and / or a case where the reception power is lower than a predetermined threshold.

When the AP / PCP 300 receives the SSW frame of S004 during the A-BFT period (S005: YES), the AP / PCP 300 determines the best sector of the STA 100, and stores the information of the best sector in the memory in preparation for communication with the STA 100. (S006).

Next, the AP / PCP 300 transmits the SSW-FB frame to the STA 100 (S007). The AP / PCP 300 may transmit the SSW-FB frame to another STA 200. Alternatively, the AP / PCP 300 may transmit a Probe response in DTI without transmitting the SSW-FB frame to any STA (see S012). Alternatively, the AP / PCP 300 may transmit the SSW-FB frame using the best sector notified by the SSW frame in the A-BFT period. Alternatively, the AP / PCP 300 may transmit the information on the best sector of the STA 100 by including it in the SSW-FB frame.

On the other hand, if the STA 100 has not received the SSW-FB frame of S007 corresponding to the SSW frame transmitted in S004 (S008: NO), the flow proceeds to S012. Then, the STA 100 waits for reception of a Probe response.

When the STA 100 receives the SSW-FB frame of S007 corresponding to the SSW frame transmitted in S004 (S008: YES), the information on the best sector included in the SSW-FB frame is prepared for communication with the AP / PCP 300. Is stored in the memory (S009).

Then, the STA 100 determines that the initial BFT between the AP / PCP 300 and its own STA 100 is completed (success) (S010). That is, the STA 100 can communicate with the AP / PCP 300 using the best sector. Discovery is ongoing.

Next, the STA 100 may transmit a Probe request to the AP / PCP 300 in the DTI (not shown in FIG. 7). Note that the STA 100 may transmit an SSW frame including DR = 1 in S004, and after completing the initial BFT, may shift to S012 and wait for reception of a Probe response without transmitting a Probe request.

On the other hand, when the AP / PCP 300 receives the Probe request and there is no reception error, the AP / PCP 300 transmits an ACK frame to the STA 100 after SIFS (Short InterFrame Space) (for example, 3 μsec) (S011).

Next, the AP / PCP 300 transmits a Probe response in DTI (S012). The AP / PCP 300 may transmit the probe response including information on the best sector of the STA 100.

The STA 100 receives the Probe response of S012 in the DTI. When the received Probe response includes the best sector information of the STA 100, the STA 100 stores the best sector information in the memory in preparation for communication with the AP / PCP 300 (S013).

Next, when the Probe response includes information on the best sector of the STA 100, the STA 100 determines that the initial BF is completed (success) (S014). That is, the STA 100 can communicate with the AP / PCP 300 using the best sector.

Next, the STA 100 stores the AP / PCP 300 included in the Probe response and the BSS information (scan result) managed by the AP / PCP 300 in the memory (S015). Note that the MAC processor of the STA 100 may notify the host controller of the scan result.

Then, the STA 100 completes discovery for the AP / PCP 300 (S016). Since the STA 100 performs discovery for another AP / PCP (not shown), the flow returns to S001 on the same radio channel or after switching the radio channel, and the discovery for other AP / PCP may be repeated. good.

FIG. 8 is a block diagram showing an example of the configuration of the STA (communication device) 100.

The antenna array transmits and receives radio signals.

The reception RF (Radio Frequency) circuit converts the radio signal received by the antenna array into a reception analog baseband signal. The reception RF circuit changes the reception gain (gain) and phase of the signal input from the antenna array in accordance with the reception sector ID (which may be the same sector as the transmission best sector) specified by the PHY reception circuit, and receives the reception antenna. Control the directivity of The reception RF circuit measures the reception quality for each received transmission sector sweep frame.

An A / D (analog / digital converter) circuit converts a received analog baseband signal into a received digital baseband signal.

A PHY (Physical Layer) receiving circuit performs synchronization, equalization, demodulation and / or decoding processing on the received digital baseband signal to generate received frame data.

A MAC (Media Access Control) processor identifies and processes a MAC frame from received frame data.

Identifying a MAC frame means determining the type of MAC frame (for example, MAC data frame, DMG beacon, Probe response). Further, in the processing of the MAC frame, for example, error detection is performed by checking FCS (Frame Check Sequence), and data of each field is acquired according to the format of the identified MAC frame. It is included.

Also, the MAC processor extracts user data from the MAC data frame and outputs it to the host controller. The MAC processor generates a MAC data frame from user data input from the host controller.

Further, when receiving the DMG beacon, the MAC processor generates an SSW frame including DR = 1 (see S004 in FIG. 7). Further, when receiving an SSW frame including DR = 1, the MAC processor may generate a Probe response (see S012, AP / PCP 300 processing in FIG. 7). Further, the MAC processor may make a discovery request to the host controller.

A frame generated by the MAC processor is referred to as transmission frame data (for example, including the above-described MAC data frame, SSW frame, and Probe response).

The PHY transmission circuit performs encoding, modulation, PHY frame formation and filtering on the transmission frame data to generate a transmission digital baseband signal.

A D / A (digital analog converter) circuit converts a transmission digital baseband signal into a transmission analog baseband signal.

The transmission RF circuit converts the transmission analog baseband signal into a transmission radio signal. Further, the transmission RF circuit controls the directivity of the transmission antenna by changing the transmission gain (gain) and phase of signals output to the antenna array 1001 according to the transmission sector ID (transmission best sector) designated by the PHY transmission circuit. To do.

The host controller controls the MAC processor to generate transmission user data and / or process reception user data. The host controller may generate a Probe request in response to a discovery request from the MAC processor and input it to the MAC processor.

FIG. 9 is a detailed block diagram showing an example of the configuration of the MAC processor.

The message generation circuit generates a transmission MAC frame, for example, a DMG beacon and an SSW frame.

The message processing circuit identifies and processes the received MAC frame.

The BFT control circuit controls a message generation circuit, a message processing circuit, a PHY transmission circuit, and a PHY reception circuit during BFT processing, and controls transmission and reception of DMG beacons and SSW frames. During the BFT process, for example, the sector sweep in the BTI in S002 of FIG. 7 and the sector sweep in the A-BFT period in S004. The BFT control circuit also outputs a control signal for selecting the AP / PCP or STA transmission best sector based on the reception quality measured by the reception RF circuit to the PHY transmission circuit.

As described above, the STA 100 includes a field indicating a discovery request (DR = 1) in the SSW frame and transmits it during the A-BFT period, and transmits a Probe response including the beamforming feedback information to the AP / PCP 300. To request. Accordingly, even when the AP / PCP 300 does not transmit the SSW-FB frame, or when the STA 100 does not receive the SSW-FB frame or when it is difficult to receive the SSW-FB frame, the STA 100 receives the Probe response from the AP / PCP 300 and performs discovery. Can be completed.

Even when the AP / PCP 300 does not transmit the SSW-FB frame, or when the STA 100 does not receive the SSW-FB frame or when it is difficult to receive the STA 100, for example, until the next BTI or A-BFT period, Waiting for frame transmission can be avoided, or beamforming in DTI can be omitted. Therefore, the delay required for discovery can be shortened.

The STA 100 can complete the BFT even when the AP / PCP 300 does not transmit the SSW-FB frame and / or when the STA 100 does not receive the SSW-FB frame or is difficult to receive. Therefore, the communication quality with the AP / PCP 300 can be improved using the best sector. Also, beamforming retries can be reduced, and interference with the AP / PCP 300 and / or other STAs can be reduced.

(Modification of Embodiment 1)
<Modification 1-1>
The AP / PCP 300 may receive an SSW frame including a field indicating a discovery request (DR = 1), and transmit a field indicating that it corresponds to a response in a DMG beacon in DTI.

FIG. 10 is a diagram illustrating an example of a procedure in which the STA 100 and the STA 200 perform an active scan on the AP / PCP 300. The AP / PCP 300 receives the SSW frame including the field indicating the discovery request (DR = 1), and transmits the field indicating that it corresponds to the response including the DMG beacon in the DTI.

FIG. 11 is a diagram showing an example of the format of the DMG beacon. The DMG beacon and DMG Beacon frame body are the same as those in the 11ad standard, and thus detailed description thereof is omitted.

The 11ad standard DMG beacon (not shown) includes a 6-bit Reserved subfield in the SSW field, whereas the DMG beacon in FIG. 11 includes a 5-bit reserved subfield and a 1-bit Discovery in the SSW field. Request Supported (DRS: Discovery request support availability) subfield.

When the STA 100 receives a DMG beacon in which the DRS field in FIG. 11 is set to 1 (DRS = 1), the STA 100 may transmit an SSW frame including DR = 1 in the A-BFT period. Since DRS = 1 is set, the STA 100 can determine that the AP / PCP 300 has a function of transmitting the Probe response of FIG.

STA 100 may transmit the SSW frame set to DR = 0 in the A-BFT period when receiving the DMG beacon in which the DRS field in FIG. 11 is not set to 1 (DRS = 0).

When the DMG beacon does not include the Discovery Request Supported subfield, it is difficult for the STA to determine whether the AP / PCP supports DR = 1.

Therefore, when the STA transmits an SSW frame including DR = 1 in the A-BFT period, the AP / PCP 300 may not transmit a Probe response including beamforming feedback information in the DTI.

For this reason, it is difficult for the STA to determine whether to wait for receiving a Probe response in the DTI or to perform a sector sweep in the DTI. In this case, for example, in the DTI, the STA may wait for a Probe response for a certain period and perform a sector sweep after the certain period. However, in this case, the delay increases due to waiting for a certain period.

If the DMG beacon includes a Discovery-Request-Supported subfield and DRS = 1, the STA transmits an SSW frame including DR = 1 in the A-BFT period and includes beamforming feedback information in the DTI A probe response may be awaited. When DRS = 0, the STA may perform a sector sweep in DTI. As a result, the STA can omit waiting for a certain period of time and can reduce the delay due to discovery.

<Modification 1-2>
The STA 100 may transmit the SSW frame including a field or subfield indicating the type of discovery request in the A-BFT period.

FIG. 12 is a diagram illustrating an example of a procedure in which the STA 100 and the STA 200 perform an active scan on the AP / PCP 300. The

STAs

100 and 200 transmit an SSW frame in which DR Type is added during the A-BFT period.

FIG. 13 is a diagram showing an example of the format of the SSW frame. The Discovery Request field of the SSW frame of FIG. 4 is 1 bit, whereas the Discovery Request field of the SSW frame of FIG. 13 includes two or more bits.

When the STA 200 transmits an SSW frame with the value of the Discovery （Request field set to 2 (Discovery request (+ Multi-band)), the AP / PCP 300 that has received the SSW frame receives a Multi-band element in the Probe response in the DTI. Send including

When the STA 200 receives the Probe response including the Multi-band element, the AP / PCP 300 regarding a frequency band (for example, 2.4 GHz band, 5 GHz band) different from the frequency band (for example, 60 GHz band) in which active scanning is performed. (For example, a radio channel number used by a 2.4 GHz band BSS).

For example, after establishing a connection with the AP / PCP 300 in the 60 GHz band, the STA 200 requests a probe from the AP / PCP 300 in a frequency band (for example, 2.4 GHz band) different from the 60 GHz band based on the information acquired by the Multi-band element. Alternatively, an association request frame may be transmitted to establish a 2.4 GHz band connection.

The 2.4 GHz band connection may be used as an alternative connection when the 60 GHz band connection is disconnected. The STA 200 can determine a channel for transmitting a 2.4 GHz band Probe request frame or an association request frame based on information of the Multi-band element. Therefore, the STA 200 can shorten the discovery time in the 2.4 GHz band by scanning the corresponding channel in the 2.4 GHz band.

When the STA 100 transmits an SSW frame with the value of the Discovery Request field set to 3 (Discovery request (+ Neighbor Report)), the AP / PCP 300 that has received the SSW frame receives a Neighbor Report element in the Probe response in DTI. Send including

When the STA 100 receives the Probe response including the Neighbor Report element, the STA 100 can obtain information on other AP / PCP 300 around the AP / PCP 300.

For example, based on the Neighbor Report element, the STA 100 may perform active scan by selecting a channel with a high probability that other AP / PCP can be found by active scan. As a result, discovery delay for other AP / PCP 300 can be shortened.

As described above, the

STAs

100 and 200 may request the AP / PCP 300 for additional element types to be included in the Probe request by appropriately setting the value of the Discovery Request field of the SSW frame.

As shown in FIG. 13, the value of the DiscoveryDisRequest field may be associated with the presence and type of the requested element. Further, the Discovery Request field may be defined as a bitmap, and the bit may be associated with the presence / absence of a request for each element. For example, the first bit may be notified as Discovery Request, the second bit as Multi-band element request, and the third bit as Neighbor report element request as 1: Yes, 0: No. .

<Modification 1-3>
The STA 100 and the STA 200 may transmit a field or subfield indicating the number of TRN-R (Receive training) subfields included in the SSW frame in the A-BFT period.

FIG. 14 is a diagram illustrating an example of a procedure in which the STA 100 and the STA 200 perform an active scan on the AP / PCP 300. TRN = 1 is added to the SSW frame transmitted by the STA2 in the A-BFT period, and the TRN-R subfield is added to the Probe response addressed to the STA2.

FIG. 15 is a diagram showing an example of the format of the SSW frame. Compared with the SSW frame in FIG. 4, the SSW frame in FIG. 15 includes a Number of TRN-R subfield, and the number of bits in the Reserved subfield is small.

The STA 200 transmits a value including the value corresponding to the number of receiving antenna sectors of the STA 200 in the Number of 値 TRN-R subfield of the SSW frame of FIG. For example, 16 times the value of the Number of TRN-R subfield may indicate the number of received sectors of the STA 200.

When the STA 200 transmits the SSW frame with the value of the Number of TRN-R subfield set to 1 or more, the AP / PCP 300 that has received the SSW frame responds to the value of the Number of TRN-R subfield in the DTI. A TRN field including a certain number of TRN-R subfields is added to the Probe response and transmitted.

When receiving the Probe response with the TRN field added, the STA 200 receives the TRN-R subfield using the reception sector switched for each TRN field, measures the reception quality, and performs the BFT of the reception antenna. Also good. The STA 200 may select the best receiving antenna and receiving sector by receiving beamforming.

When the STA 200 has an antenna pattern reciprocity or the like in which the relationship between the directivity characteristic of the transmission antenna and the directivity characteristic of the reception antenna is known, the STA 200 selects the best transmission antenna and transmission sector based on the beamforming result of the reception antenna. May be.

The antenna reciprocity is highly likely that the antenna number to which the best transmission sector belongs and the antenna number to which the best reception sector belongs are the same when the STA 200 includes a plurality of transmission antennas and a plurality of reception antennas. Means the antenna configuration.

For example, the first transmission antenna and the first reception antenna have the same cover range (for example, the communication area is in the front direction), and the second transmission antenna and the second reception antenna have the same cover range. When the communication area is in the back direction (for example, when the coverage area of the first transmission antenna and the first reception antenna, and the second transmission antenna and the second reception antenna is small), the STA 200 performs antenna reciprocation. Provide a city. Note that the first transmitting antenna and the first receiving antenna may be the first antenna for both transmission and reception. Further, the second transmission antenna and the second reception antenna may be a second transmission / reception antenna.

The antenna pattern reciprocity means an antenna configuration in which the sector number of the best transmission sector and the sector number of the best reception sector are likely to be the same. For example, the first transmitting antenna and the first receiving antenna have the same directivity pattern. Also, for example, the first transmission / reception shared antenna (antenna array in FIG. 8) has the same directivity pattern during transmission and reception.

The STA 200 performs BFT of the receiving antenna using the TRN-R subfield and selects the best receiving sector. Therefore, the STA 200 can improve the communication performance with the AP / PCP 300, and can perform processing after the Probe response (for example, reception of an association response frame (not shown)) at high speed and / or at a low error rate.

Also, the STA 200 selects the best transmission sector using the result of performing the BFT of the receiving antenna using the TRN-R subfield. Therefore, even when the STA 200 does not receive the SSW-FB frame, the STA 200 improves the communication performance with the AP / PCP 300, and performs high-speed processing after the Probe response (for example, transmission of an association request frame (not shown)). Can be done at a low error rate.

<Modification 1-4>
The STA 100 and the STA 200 may transmit an SSW frame including the SIFS turnover field or subfield in the A-BFT period.

FIG. 16 is a diagram illustrating an example of a procedure in which the STA 100 and the STA 200 perform an active scan on the AP / PCP 300. In FIG. 16, SIFS = 1 is added to the SSW frame transmitted by the STA 200 in the A-BFT period.

FIG. 17 is a diagram showing an example of the format of the SSW frame. Compared with the SSW frame of FIG. 4, the SSW frame of FIG. 17 includes the SIFS Turnover subfield and the number of bits of the Reserved subfield is small.

FIG. 18 is a diagram showing another example of the format of the SSW frame. Compared with the SSW frame of FIG. 17, the SSW frame of FIG. 18 includes a Discovery Request Type field.

The STA 100 and the STA 200 may transmit the SSW frame with the value of the Discovery Request field of FIG. 18 set to 0 instead of setting the value of the Discovery Request field of FIG. 17 to 0. The STA 100 and the STA 200 may transmit the SSW frame by setting the value of the Discovery Request field of FIG. 18 to 1 instead of setting the value of the Discovery Request field of FIG. 17 to 1 and the SIFS Turnover field to 0. .

The STA 100 and the STA 200 may transmit the SSW frame by setting the value of the Discovery Request field of FIG. 18 to 2 instead of setting the value of the Discovery Request field of FIG. 17 to 1 and the SIFS Turnover field to 1. . The value “3” of the Discovery Request Type field is Reserved.

In the SSW frame of FIG. 18, the Reserved setting (Discovery Request Type field value 3) may be used for future function expansion.

When the AP / PCP 300 receives an SSW frame in which the value of the SIFS Turnover subfield is set to 1, the AP / PCP 300 sets the destination address of the Probe response to, for example, a unicast address addressed to the STA 200 and transmits the Probe response in the DTI. .

When the STA 200 receives a Probe response including a unicast address as a destination address, the STA 200 transmits an Ack frame after SIFS time (3 μsec). Before transmitting the Ack frame, the STA 200 analyzes the beamforming feedback information included in the Probe response to determine the best sector, sets the transmission sector to the best sector, and transmits the Ack frame.

FIG. 19 is a diagram illustrating an example of a procedure in which the STA 100 and the STA 200 perform an active scan on the AP / PCP 300.

When the AP / PCP 300 receives the SSW frame in which the value of the SIFS Turnover subfield is set to 0, the AP / PCP 300 sets the destination address of the Probe response to the broadcast address and transmits the Probe response in the DTI.

When the STA 100 receives the Probe response including the broadcast address as the destination address, the STA 100 determines whether the address of the beamforming feedback information included in the Probe response (a MAC address field in FIG. 29 described later) is addressed to the STA 100, and is addressed to the STA 100. If it is, the best sector is determined by analyzing the beamforming feedback information.

When the STA 200 receives a Probe response including a unicast address as a destination address in the DTI, the STA 200 may perform transmission of Ack (not shown) after analyzing beamforming feedback information and setting a transmission sector in the SIFS time. . By transmitting Ack, the STA 200 can perform highly reliable communication. For example, the AP / PCP 300 may transmit a Probe response including a unicast address as a destination address, and may retransmit the Probe response when an Ack frame is not received after the SIFS time.

When the STA 100 receives a Probe response including a broadcast address as a destination address in the DTI, the STA 100 may analyze the beamforming feedback information in a time longer than SIFS. Thereby, even a STA with low processing capability can receive a Probe response including beamforming feedback information and complete discovery.

When the AP / PCP 300 receives an SSW frame in which the value of the SIFS Turnover subfield is set to 0 in the A-BFT period from the STA 100, the AP / PCP 300 transmits the SSW-FB frame to the STA 100, and performs beam feedback as a Probe response in the DTI. The probe response may be transmitted by setting the destination address as the unicast address addressed to the STA 100 without including the information.

The STA 100 analyzes the beamforming feedback information after receiving the SSW-FB frame. Therefore, the analysis of the beamforming feedback information when receiving the Probe response may be omitted. Thereby, the STA 100 can transmit the Ack frame after the SIFS time even if the processing capability is low.

When the AP / PCP 300 receives an SSW frame in which the value of the SIFS Turnover subfield is set to 0 from the STA 100 and omits transmission of the SSW-FB frame to the STA 100, the AP / PCP 300 includes the beam forming information of the STA 100 and includes the destination address. A Probe response set to the broadcast address may be transmitted.

The STA 100 and the STA 200 may set the value of the SIFS Turnover subfield according to the processing capability for the beam feedback information. Thereby, even when the processing capability for the beam feedback information is low, it is possible to receive the probe response including the beamforming feedback information. Therefore, the delay required for discovery can be shortened.

<Modification 1-5>
FIG. 20 is a diagram illustrating an example of a procedure in which the STA performs an active scan on the AP / PCP. In FIG. 20, the STA 200 may transmit a Short SSW packet including a field indicating a discovery request instead of the SSW frame in the A-BFT period.

FIG. 21 is a diagram showing an example of the format of the Short SSW packet. The field indicating the discovery request is the same as the discovery request subfield of FIG.

Since the Short SSW packet has a shorter packet length than the packet including the SSW frame, the STA 200 transmits more Short SSW packets than the SSW frame while switching the transmission sector for each Short SSW packet in the A-BFT period. Since the STA 200 can perform training of a large number of transmission sectors in the A-BFT period, the accuracy of beam forming is improved. Therefore, the communication quality with the AP / PCP 300 (after receiving the Probe response) is improved.

Also, since the Short SSW packet transmitted by the STA 200 has a short packet length, the probability of causing interference to other STAs (for example, the STA 100 not shown) and / or the probability of receiving interference from other STAs decreases. This increases the probability that the AP / PCP 300 receives valid SSW frames and Short SSW packets from a plurality of STAs.

The STA 200 sets the field indicating the discovery request of the Short SSW packet shown in FIG. 21 to DR = 1 and transmits the Short SSW packet. When the AP / PCP 300 receives valid SSW frames and Short SSW packets from a plurality of STAs, the AP / PCP 300 performs the following processing. That is, the AP / PCP 300 transmits a Probe response frame including BF feedback to the STA that transmits the SSW frame or the Short SSW packet indicating the discovery request field with DR = 1. The STA 200 can receive the Probe response frame and complete the BFT and discovery for the AP / PCP 300.

Thus, the STA 200 transmits a Shorthor SSW packet including a field indicating a discovery request. Therefore, when a plurality of STAs perform BFT in the A-BFT period, the delay until receiving the Probe response frame and completing the BFT and discovery for the AP / PCP 300 is shortened with high probability.

<Modification 1-6>
In the A-BFT period, the STA 200 may transmit a Short SSW packet including a field indicating a discovery request and a control trailer instead of the SSW frame.

FIG. 22 is a diagram illustrating an example of a procedure in which the STA 200 performs an active scan on the AP / PCP 300. In FIG. 22, DR = 1 is added to the ShortSSSW packet that STA2 transmits in the A-BFT period.

FIG. 23 is a diagram showing an example of the format of the Short SSW packet. In FIG. 20, the Short２００SSW packet (ordinary Short SSW packet) used by the STA 200 includes an L-STF (Legacy Short Training Field), L-CEF (Legacy Channel Estimation Field), L-Header (Legacy Header), and Payload. FIG. 21 is a diagram showing a Payload format of a ShortSSSW packet. The Short SSW packet of FIG. 23 includes a control trailer as compared with the Short SSW packet of FIG.

The control trailer includes a Discovery Criteria field, a Reserved field, and an error detection code field (CTCS: Control Trailer Check Sequence), which are additional information for performing discovery. The Discovery Criteria field includes a BSS Type subfield, a Short SSID (Service Set IDentifier) subfield, and an RNS Info subfield.

The STA 200 sets the value of the BSS Type subfield to a value indicating Infrastructure BSS (BSS Type = 3) and transmits the Short SSW packet. When the BSS (Basic Service Set) is Infrastructure BSS, the AP / PCP 300 performs a response to the STA 200 (transmission of a Probe response), and the BSS (Basic Service Set) is not Infrastructure BSS (for example, PBSS (Personal Service BSS, In the case of BSS Type = 2) or IBSS (independent BSS, BSS Type = 1)), the response to the STA 200 may be omitted.

The AP / PCP 300 responds to the STA 200 when the value of the BSS 同じ Type subfield of the received Short SSW packet indicates the same type as the BSS of the AP / PCP 300, and omits the response when indicating a different type. good.

The STA 200 may select a BSS to be connected according to an application using communication, and set a value of the BSS Type subfield. As a result, responses from access points that are not intended to be connected can be suppressed, discovery delay can be reduced, and transmission of unnecessary packets by the AP / PCP 300 can be reduced.

For example, when the application used by the STA 200 is an Internet browser, the STA 200 may connect to an Infrastructure BSS access point for transmitting IP packets. When the application used by the STA 200 is video transmission to a large screen display, the STA 200 may be connected to a PCP of PBSS for performing one-to-one communication with the display.

The STA 200 may set the value of the Short SSID field to the 32-bit hash value of the SSID (Service Set IDentifier) (identifier for identifying the BSS) of the access point to be connected, and transmit the Short SSW packet.

The AP / PCP 300 responds to the STA 200 when the value of the Short SSID subfield of the received Short SSW packet matches the hash value of the SSID of the BSS of the AP / PCP 300, and omits the response to the STA 200 when they do not match. May be.

For example, the STA 200 performs discovery by specifying an AP / PCP from a list of SSIDs of neighboring AP / PCPs provided by other AP / PCPs (not shown) or SSID values obtained by other communication methods. . As a result, it is possible to omit processing for a response from an AP / PCP that is not specified, and to shorten the discovery delay.

The STA 200 may determine the value of the RSN Info field so that a part of the field in the RSN element defined in the 11ad standard is included. The value of the RSN Info field includes information on presence / absence of support for security functions (for example, concealment and authentication) in wireless connection and / or parameters.

The AP / PCP 300 may respond to the STA 200 when the security function indicated by the RSNRS Info field of the received Short SSW packet is supported, and may omit the response to the STA 200 when the security function is not supported.

In this way, the STA 200 transmits the Short SSW frame including the value of the Discovery Criteria field. As a result, it is possible to omit processing for a response from an AP / PCP of a BSS that does not conform to an application or an AP / PCP that is not specified, and to shorten a discovery delay.

<Modification 1-7>
The PCP / AP 300 may transmit a SSW-FB frame including a Discovery Request Ack field indicating that an SSW frame including DR = 1 has been received in the A-BFT period.

FIG. 24 is a diagram illustrating an example of a procedure in which the STA 100 performs an active scan on the AP / PCP 300. In FIG. 24, DR = 1 is added to the SSW field that the STA 100 transmits in the A-BFT period, and DRA = 1 is added to the SSW-FB field that the AP / PCP 300 transmits in the A-BFT period.

FIG. 25 is a diagram showing an example of the format of the SSW-FB frame. The SSW-FB frame includes a Frame-Control field, Duration field, RA field, SSW Feedback (SSW-FB) field, BRP Request field, Beamformed Link Maintenance field, and FCS field.

The SSW Feedback field includes a Sector Select subfield, a DMG Antenna Select subfield, an SNR Report subfield, a Poll Required subfield, a Discovery Request ACK (DRA) subfield, and a Reserved subfield.

When the PCP / AP 300 receives an SSW frame including DR = 1 from the STA 100 during the A-BFT period, the PCP / AP 300 transmits an SSW-FB frame in which the value of the Discovery Request Ack subfield is set to DRA = 1 to the STA 100.

When the PCP / AP 300 receives an SSW frame including DR = 0 from the STA 100 during the A-BFT period, the PCP / AP 300 transmits an SSW-FB frame in which the value of the Discovery Request Ack subfield is set to DRA = 0 to the STA 100.

Also, when the PCP / AP 300 receives an SSW frame including DR = 1 from the STA 100 during the A-BFT period and does not transmit a Probe response to the STA 100, the PCP / AP 300 sets the value of the Discovery Request Ack subfield to the DRA during the A-BFT period. SSW-FB frame set to = 0 is transmitted to the STA 100.

Note that “when the PCP / AP 300 does not transmit a Probe response to the STA 100” does not support a function of transmitting a Probe response (see Embodiment 1) even when an SSW frame including DR = 1 is received, for example. Including cases.

Also, “when the PCP / AP 300 does not send a Probe response to the STA 100”, for example, the value of the Discovery Criteria field (see FIG. 23) included in the SSW frame including DR = 1 matches the condition of the PCP / AP 300 This includes the case where it is not performed (for example, BSS type is different).

Note that the PCP / AP 300 does not need to transmit the SSW-FB frame when it does not receive the SSW frame.

When the STA 100 receives the SSW-FB frame including the Discovery Request Ack subfield, the STA 100 determines whether or not to wait for a Probe response in the DTI.

The STA 100 waits for a Probe response when the value of the received Discovery ＝ Request Ack subfield is DRA = 1. Thereby, the STA 100 can avoid transmission of an unnecessary Probe request.

The STA 100 transmits a Probe request when the value of the received Discovery Request Ack subfield is DRA = 0. Thereby, the STA 100 can avoid a delay due to unnecessary waiting for a Probe response.

When the AP / PCP 300 sends the SSW-FB frame to the STA 100 with the value of the Discovery Request Ack subfield set to DRA = 1, the AP / PCP 300 does not send the Probe response to the STA 100 until the Probe request is received. As a result, the AP / PCP 300 can avoid sending an unnecessary Probe response.

<Modification 1-8>
After transmitting the SSW-FB frame in the A-BFT period, the PCP / AP 300 further transmits a frame (for example, ATIM) instead of the SSW-FB frame indicating that the SSW frame including DR = 1 is received in the DTI. (Announcement traffic indication message) frame or SSW-ACK frame) may be transmitted.

FIG. 26 is a diagram illustrating an example of a procedure in which the STA 100 and the STA 200 perform an active scan on the AP / PCP 300.

AP / PCP 300 receives the SSW frame including DR = 1 from STA 100 and STA 200 in the A-BFT period. The AP / PCP 300 may transmit the SSW-FB frame to one of the SSW frame transmission source STAs (STA 100 in FIG. 26) in the A-BFT period.

The AP / PCP 300 may transmit an SSW-ACK frame to the STA 200 in DTI. The AP / PCP 300 may transmit the SSW-ACK frame to the STA 200 that did not transmit the SSW-FB frame, among the SSW frame transmission source STAs 100 and 200.

Note that the AP / PCP 300 may transmit an ATIM frame to the STA 200 instead of the SSW-ACK frame in the DTI.

When the STA 200 receives the SSW-ACK frame from the AP / PCP 300, it waits for a Probe response. If the STA 200 does not receive the SSW-ACK frame from the AP / PCP 300, the STA 200 may determine that the BFT in the A-BFT period has not been completed, and execute another procedure, for example, beamforming in DTI. Thereby, the STA 200 can avoid waiting for a Probe response, and can avoid an increase in delay. In addition, the STA 200 can reduce power consumption by shifting to a sleep (power save) mode in which standby is stopped until the next BTI.

Note that the AP / PCP 300 may transmit an SSW-ACK frame at the beginning of the DTI. The waiting time for the SSW-ACK frame is shorter than the waiting time for the Probe response. Therefore, the STA 200 can quickly determine whether or not the BFT has been completed, and the standby time can be shortened.

In addition, the AP / PCP 300 may set an ATI (Announcement transmission interval) between the A-BFT period and the DTI, and may transmit an ATIM frame. The ATI may be set as a shorter period than the DTI. Since the standby time of the ATIM frame in ATI is shorter than the standby time of the Probe response in DTI, the STA 200 can determine whether or not the BFT is completed early, and the standby time can be shortened.

<Modification 1-9>
In the DTI, the PCP / AP 300 may continuously transmit a Probe response addressed to the STA 100 and the STA 200 at an SBIFS (Short BeamForming Interframe Space) interval (1 μsec), similarly to the transmission of the DMG beacon and the SSW frame.

FIG. 27 is a diagram illustrating an example of a procedure in which the STA 100 and the STA 200 perform an active scan on the AP / PCP 300.

PCP / AP 300 receives SSW frames including DR = 1 from a plurality of STAs in the A-BFT period.

The PCP / AP 300 transmits a Probe response addressed to each STA in a DTI at short intervals such as an SBIFS interval (1 μsec) or a SIFS interval (3 μsec).

Note that the AP / PCP 300 may set the destination address of the Probe response as a broadcast address. Thereby, since the STA that has received the Probe response can omit the transmission of the ACK frame, the AP / PCP 300 can transmit the Probe response at a short interval.

Thus, the PCP / AP 300 can efficiently transmit a Probe response to a plurality of STAs, and the STA 100 and the STA 200 can shorten the time required for waiting for a Probe response.

<Modification 1-10>
The PCP / AP 300 may transmit the beamforming feedback information of a plurality of STAs (for example, the STA 100 and the STA 200) in the Probe response in the DTI.

FIG. 28 is a diagram illustrating an example of a procedure in which the STA 100 and the STA 200 perform an active scan on the AP / PCP 300.

FIG. 29 is a diagram showing an example of the format of a Probe response. The Probe response in FIG. 29 adds a MAC address field to the Beamforming Feedback element as compared with the Probe response in FIG.

In FIG. 29, the AP / PCP 300 may include a plurality of Beamforming Feedback frames in the Probe Response frame body of the Probe response. For example, the AP / PCP 300 includes two Beamforming Feedback frames in the Probe Response frame body, includes beamforming feedback information regarding the STA100 in the first Beamforming Feedback frame, and sets the MAC address field to the MAC address of the STA100. Good. Further, the AP / PCP 300 may include the beam forming feedback information regarding the STA 200 in the second Beamforming Feedback frame, and set the MAC address field to the MAC address of the STA 200.

When the sector used for transmitting the frame addressed to STA 100 and the sector used for transmitting the frame addressed to STA 200 are the same, AP / PCP 300 includes the beam forming feedback information of STA 100 and STA 200 in one Probe response, and includes the same sector. May be used. For example, when the best sector of the AP / PCP 300 specified by the feedback information included in the SSW frame by the STA 100 is the same as the best sector of the AP / PCP 300 specified by the feedback information included in the SSW frame by the STA 100, the AP / PCP 300 The same sector may be set as the sector used for transmission of the addressed frame and the sector used for transmission of the frame addressed to the STA 200.

As described above, the AP / PCP 300 includes the information of the Probe responses addressed to a plurality of STAs in each Beamforming Feedback frame of one Probe response. As a result, a delay required for transmitting a plurality of Probe responses (including carrier sense and backoff for each frame) can be reduced to a delay required for transmitting a single Probe response.

<Modification 1-11>
The PCP / AP 300 may transmit the information requesting the Probe response from the STA 100 by including the Probe response in the DTI.

FIG. 30 is a diagram illustrating an example of a procedure in which the STA 100 performs an active scan on the AP / PCP 300.

The PCP / AP 300 transmits information requesting a Probe response from the STA 100 in the DTI by including it in the Probe response. For example, a 1-bit Solicit Probe Response subfield is added to the Beamforming Feedback field of the Probe response in FIG. 29, and the value of the subfield is set to 1. The Beamforming Feedback field is an example, and the Solicit Probe Response subfield may be added to fields other than the Beamforming Feedback field. Further, the Reserved subfield of fields other than the Beamforming Feedback field may be replaced with a Solicit Probe Response subfield.

When the STA 100 receives a Probe response in which the Solicit Probe Response subfield is set to 1, after acquiring the transmission right (for example, performing carrier sense), the STA 100 transmits the Probe response to the AP / PCP 300.

The AP / PCP 300 omits the transmission of the Probe request addressed to the STA 100 and receives the Probe response. As a result, the AP / PCP 300 can acquire information on the STA 100 by reducing the consumption of radio resources.

<Modification 1-12>
The PCP / AP 300 may transmit by adding a TRN field including the TRN-R subfield to the Probe response in the DTI. Since the TRN-R subfield has already been described with reference to FIG. 22, description thereof is omitted here.

FIG. 31 is a diagram illustrating an example of a procedure in which the STA 100 and the STA 200 perform an active scan on the AP / PCP 300.

The STA 200 may perform reception beamforming training by switching the reception sector for each TRN-R subfield to be received in the DTI. The STA 200 determines the best receiving sector in accordance with the result of receiving beamforming training.

Note that if the STA 200 has antenna pattern reciprocity, and if the correspondence between the directivity patterns of the transmission antenna and the reception antenna is known, the STA 200 can select the best transmission sector from the result of the training of the reception beamforming. good. The best transmission sector determined in this way can be more accurate than the feedback information of the Probe response. Therefore, the STA 200 can improve communication quality.

FIG. 32 is a block diagram showing an example of the configuration of the communication devices (AP / PCP 300 and STA 200). Although similar to FIGS. 8 and 9, the PHY transmitter circuit and the PHY receiver circuit are described in detail.

When the AP / PCP 300 transmits a Probe response in DTI, the message generation circuit of the MAC processor generates frame data (see FIG. 5) of the Probe response and inputs the frame data to the PHY transmission circuit. The PHY transmission circuit generates frame data by encoding and modulating the frame data.

Further, the PHY transmission circuit includes a TRN subfield generation unit. The TRN subfield generation unit generates a TRN-R subfield. The PHY transmission circuit combines the frame data and the TRN-R subfield, converts it into an analog signal at D / A, and transmits it from the transmission RF circuit.

When the STA 200 receives the Probe response to which the TRN-R subfield is added, the BFT module of the MAC processor controls the PHY reception circuit to switch the reception sector for each TRN-R subfield. As an example of the control signal (CONTROL) output from the MAC processor to the PHY receiving circuit, there is a list of receiving sector numbers used for receiving the TRN-R subfield.

The PHY reception circuit controls the reception RF circuit based on the control signal input from the MAC processor and the information of the PHY header added to the Probe response, and controls the switching of the reception sector.

The PHY receiving circuit includes a TRN subfield processor. The TRN subfield processor calculates reception quality (for example, reception signal power, S / N ratio) for each reception sector from the received TRN-R field signal.

The PHY receiver circuit notifies the MAC processor of the reception quality for each reception sector calculated by the TRN subfield processor (not shown in the block diagram). The BFT module of the MAC processor may determine the best receiving sector from the reception quality for each receiving sector, and may further determine the best transmitting sector from the antenna pattern reciprocity information.

(Embodiment 2)
In the first embodiment, the case has been described in which the STA performs BFT (SSW frame transmission) in the A-BFT period and is received by the AP / PCP. In the second embodiment, (1) the STA does not perform BFT (SSW frame transmission) in the A-BFT period, and (2) the STA performs BFT (SSW frame transmission) in the A-BFT period. However, the operation of the STA and the AP / PCP when the AP / PCP does not receive the SSW frame due to a transmission conflict with other STAs or when a reception error occurs will be described.

FIG. 33A is a diagram illustrating an example of a procedure according to the second embodiment in which the STA 100 performs an active scan on the AP / PCP 300.

FIG. 33A shows a case where the AP transmits an SSW-FB frame, and FIG. 33B shows a case where the AP does not transmit an SSW-FB frame.

33A and 33B, the AP / PCP 300 changes the transmission sector for each DMG beacon and transmits one or more DMG beacons.

33A and 33B, the STA 100 receives the DMG beacon. Note that another STA (STA 200) may receive the DMG beacon in the same BTI.

The operation of the STA 100 during the A-BFT period is as follows.
(1) When the STA 100 does not perform BFT (SSW frame transmission) in the A-BFT period, the AP / PCP 300 does not transmit the SSW-FB frame.
(2) The STA performed BFT (SSW frame transmission) during the A-BFT period, but the AP / PCP did not receive the SSW frame or a reception error occurred due to transmission competition with other STAs, etc. In this case, the AP / PCP 300 does not transmit the SSW-FB frame in (1) and (2).
(3) The STA 100 transmits an SSW frame that does not include DR = 1 in the A-BFT period, and the AP / PCP 300 transmits the SSW-FB frame, but the STA 100 does not receive it.

The STA 100 may apply the following procedure in the above situations (1), (2), and (3).

In the DTI, the STA 100 transmits an SSW frame including a field (DR = 1) indicating a discovery request while changing a transmission sector for each SSW frame. Since the format of the SSW frame is the same as that in FIG. 4, description thereof is omitted here.

The AP / PCP 300 receives one or more SSW frames in the DTI.

The AP / PCP 300 determines the transmission sector ID in the SSW frame with good reception quality among the received SSW frames as the best sector of the transmission source STA.

The AP / PCP 300 transmits information including the determined best sector information to the STA 100 in the SSW-FB frame.

When the STA 100 receives the SSW-FB frame, the STA 100 transmits the SSW-ACK frame using the best sector included in the SSW-FB frame.

When the field indicating the discovery request (DR = 1) is included in the SSW frame received in the DTI, the AP / PCP 300 acquires the transmission opportunity (TXOP) after receiving the SSW-Ack for the SSW-FB, and the Probe response Send. The AP / PCP 300 may include beamforming feedback information in the Probe response. The AP / PCP 300 may shorten the Probe response by omitting the beamforming feedback information.

The STA 100 receives the probe response frame including the beamforming feedback (Beamforming Feedback element) in the DTI, and based on the information (for example, the value of the Sector Select field) included in the beamforming feedback, the STA 100 and the best sector in communication. To decide. Since the STA 100 has received the Probe response from the AP / PCP 300, the discovery by the active scan procedure for the AP / PCP 300 is completed (success).

The STA 100 can receive a Probe response in the DTI even if it performs BFT (sector sweep) in the A-BFT period and does not receive the SSW-FB frame. As a result, the STA 100 can omit the BFT retry and reduce the delay required for discovery. Further, the STA 100 can omit the transmission of the Probe request, and can reduce the delay required for discovery.

FIG. 33B is a diagram illustrating an example of a procedure according to the second embodiment in which the STA 100 performs an active scan on the AP / PCP 300.

When the AP / PCP 300 detects a signal from another STA (not shown) at the reception antenna of the AP / PCP 300 before transmitting it to the STA 100 including the best sector information in the SSW-FB frame in the DTI. In order to avoid collision of transmission signals, the SSW-FB frame is not transmitted.

The AP / PCP 300 receives an RTS frame and a DMGＡＰCTS frame from another STA 200 (not shown) before or after receiving the SSW frame from the STA 100, detects that the STA 200 has acquired the transmission right, and further detects the STA 200. If the transmission right for the SSW-FB frame has not expired, the SSW-FB frame is not transmitted.

The STA 100 does not receive the SSW-FB frame from the AP / PCP 300, and therefore does not transmit the SSW-ACK frame.

When the received SSW frame includes the discovery request field (DR = 1), the AP / PCP 300 completes the transmission right held by the STA 100 (used by the STA 100 for transmitting the SSW frame and receiving the SSW-FB frame). After that, the transmission right with the STA 100 is acquired, and the probe response is transmitted including the beamforming feedback information.

The AP / PCP 300 transmits the SSW-FB frame. However, when the AP / PCP 300 does not receive the SSW-ACK frame from the STA 100, the AP / PCP 300 may transmit the probe response including the beamforming feedback information.

The STA 100 receives the Probe response including the beamforming feedback (Beamforming Feedback element) in the DTI, and selects the best sector to be used for communication with the AP / PCP 300 based on the information included in the beamforming feedback (for example, the value of the Sector Select field). decide. Further, since the Probe response from the AP / PCP 300 has been received, the discovery by the active scan procedure for the AP / PCP 300 is completed (success).

In FIG. 33B, the STA 100 can receive a probe response of the AP / PCP 300 even when it performs a BFT (eg, sector sweep) during DTI and does not receive an SSW-FB frame from the AP / PCP 300. As a result, the STA 100 can omit the BFT retry and can reduce the delay until the start of data communication due to discovery. In addition, the STA 100 can omit the transmission of a Probe request, and can reduce the delay until the start of data communication due to discovery.

FIG. 34 is a flowchart illustrating an example of a procedure in which the STA 100 performs discovery in FIGS. 33A and 33B.

First, the STA 100 starts discovery (S101).

Next, the STA 100 receives the DMG beacon transmitted from the AP / PCP 300 in the BTI (S102). The DMG beacon may be transmitted by the AP / PCP 300 in order to perform a sector sweep. That is, the AP / PCP 300 may switch the transmission direction of the radio signal (DMG beacon) by switching the transmission sector for each DMG beacon, and may transmit one or more DMG beacons. Further, the AP / PCP 300 may transmit an information element and a field indicating whether or not an A-BFT period is scheduled after the BTI in a DMG beacon.

Next, when the A-BFT period is not scheduled in the STA 100 (S103: NO-T1), the flow proceeds to S201, and the STA 100 performs beam forming in DTI. Alternatively, when the transmission opportunity (TXOP) is not obtained in the STA 100 (S103: NO-T2), the flow returns to S102, and the STA 100 may wait for the next BTI without performing beamforming in DTI.

In S201, the STA 100 changes the transmission sector for each SSW frame and transmits the SSW frame including the field (DR = 1) indicating the discovery request in the DTI for the BFT (see FIGS. 33A and 33B). . The format of the SSW frame is the same as that in FIG. Here, the STA 100 may determine the best sector of the AP / PCP 300 from the reception quality of the DMG beacon of S102 received in the BTI, and transmit the sector ID of the best sector included in the Sector Select subframe of the SSW frame.

On the other hand, the AP / PCP 300 receives the SSW frame including the field (DR = 1) indicating the discovery request in S201, determines the best sector of the STA 100, and stores the information of the best sector in the memory in preparation for communication with the STA 100. (S202).

Next, the AP / PCP 300 transmits the SSW-FB frame to the STA 100 (S203). The AP / PCP 300 may transmit the SSW-FB frame to another STA (see FIG. 33A). Further, the AP / PCP 300 may transmit the SSW-FB frame using the best sector notified by the SSW frame. Further, the AP / PCP 300 may transmit the information on the best sector of the STA 100 by including it in the SSW-FB frame. As described above, the AP / PCP 300 may not transmit the SSW-FB frame when detecting a signal from another STA (not shown), for example (see FIG. 33B).

On the other hand, when the STA 100 does not receive the SSW-FB frame from the AP / PCP 300 (S204: NO), the STA 100 proceeds to S211 described later (S205: A-3) and waits for reception of the Probe response. If the STA 100 does not receive the Probe response within a predetermined time, the flow proceeds to S201 as in the conventional 11ad standard STA, and the STA 100 may retry the sector sweep in the DTI (S205: A-1) (not shown in FIGS. 33A and 33B), or the flow proceeds to S102, and the STA 100 may retry the sector sweep in the next A-BFT period (S205: A-2) ( 33A and 33B). Here, the case where the SSW-FB frame is not received includes the case where the AP / PCP 300 does not transmit the SSW-FB frame.

When the STA 100 receives the SSW-FB frame from the AP / PCP 300 (S204: YES), the STA 100 stores the information of the best sector included in the SSW-FB frame in the memory in preparation for communication with the AP / PCP 300 (S206) (S206) (See FIG. 33A).

Next, the STA 100 transmits an SSW-ACK frame to notify the AP / PCP 300 that the SSW-FB frame has been received without error (S207), and the flow proceeds to S208 described later.

On the other hand, when the A-BFT period is scheduled in the STA 100 in S103 (S103: YES), the STA 100 transmits the SSW frame with the AP / PCP 300 as the transmission destination in the A-BFT period (S104) (FIG. 33A). (Not shown in FIG. 33B). Note that the STA 100 may transmit an SSW frame in order to perform sector sweep. That is, the STA 100 may switch the transmission sector for each SSW frame, switch the transmission direction of the radio signal (SSW frame), and transmit one or more SSW frames. This is called a responder BFT because the STA 100 performs a sector sweep in response to a sector sweep using a DMG beacon by the AP / PCP 300. Further, the STA 100 may determine the best sector of the AP / PCP 300 based on the reception quality of the DMG beacon received in the BTI, and transmit the best sector information (for example, sector ID) in the SSW frame.

If the AP / PCP 300 has not received the SSW frame of S104 (S105: NO), the flow skips the transmission of the SSW-FB frame to the STA 100 and proceeds to S201. The case where the SSW frame here is not received may include a case where there is a reception error and / or a case where the reception power is lower than a threshold value.

When the AP / PCP 300 receives the SSW frame of S104 (S105: YES), the AP / PCP 300 determines the best sector of the STA 100, and stores the information of the best sector in the memory in preparation for communication with the STA 100 (S106).

Next, the AP / PCP 300 transmits the SSW-FB frame to the STA 100 (S107). Note that the AP / PCP 300 may transmit the SSW-FB frame to another STA that has received the SSW frame. Further, the AP / PCP 300 may transmit the SSW-FB frame using the best sector notified by the SSW frame. Further, the AP / PCP 300 may transmit the information on the best sector of the STA 100 by including it in the SSW-FB frame.

On the other hand, when the STA 100 does not receive the SSW-FB frame in S107 corresponding to the SSW frame transmitted in S104 (S108: NO), the flow proceeds to S201 in order to perform beamforming in DTI.

When the STA 100 receives the SSW-FB frame in S107 corresponding to the SSW frame transmitted in S104 (S108: YES), the STA 100 stores information on the best sector included in the SSW-FB frame in preparation for communication with the AP / PCP 300. (S109).

When the STA 100 completes S207 or S109, the STA 100 determines that the initial BFT between the AP / PCP 300 and the STA 100 is complete (successful) (S208). That is, the STA 100 determines that communication with the AP / PCP 300 is possible using the best sector. At this point, discovery has not yet been completed.

Next, the STA 100 transmits a Probe request to the AP / PCP 300 in the DTI (S209).

On the other hand, if the AP / PCP 300 receives the Probe request of S208 in the DTI and determines that there is no reception error, the AP / PCP 300 transmits an ACK frame to the STA 100 after SIFS (3 μsec) (S210).

The AP / PCP 300 transmits a Probe response (S211). Note that the AP / PCP 300 may transmit the probe response including information on the best sector of the STA 100.

On the other hand, when the STA 100 receives the Probe response in S211 and determines that there is no reception error, the STA 100 transmits an ACK frame after SIFS (3 μsec) (S212).

Next, the STA 100 stores the AP / PCP 300 included in the Probe response and the BSS information (scan result) managed by the AP / PCP 300 in the memory (S213). Note that the MAC processor of the STA 100 may notify the host controller of the scan result.

Then, the STA 100 completes the discovery for the above AP / PCP 300 (S214). The STA 100 may perform discovery with respect to another AP / PCP (not shown), and may switch to the same radio channel or switch radio channels and proceed to S101 to repeat discovery.

(Modification of Embodiment 2)
33A and 33B, AP / PCP 300 transmits a DMG beacon including a field indicating that it corresponds to reception of an SSW frame including a field indicating a discovery request (DR = 1) in DTI. Alternatively, see the DMG beacon format in FIG.

Also, the STA 100 may transmit a field or subfield indicating the type of discovery request included in the SSW frame in the DTI (see the format of the SSW frame in FIG. 13).

In addition, the STA 100 may transmit a field or subfield indicating the number of TRN-R subfields in the DTI by including it in the SSW frame (see the format of the SSW frame in FIG. 15). In the DTI, the AP / PCP 300 may transmit a TRN field including a number of TRN-R subfields corresponding to the value of the Number-of TRN-R subfield added to the Probe response (the probe response in FIG. 15). See frame).

In addition, the STA 100 may transmit the SIFS Turnover field or subfield included in the SSW frame in the DTI (see the SSW frame format in FIG. 17).

In addition, the STA 100 may transmit a Short SSW packet including a Discovery Request field instead of an SSW frame in the DTI (see the format of the Short SSW packet in FIG. 21).

Also, the PCP / AP 300 may include a Discovery Request Ack field indicating that an SSW frame including DR = 1 has been received in the DTI, and transmit the SSW-FB frame.

In the second embodiment, the PCP / AP 300 may transmit the information requesting the Probe response from the STA 100 in the Probe response (see FIG. 30). When receiving a Probe response including information requesting a Probe response in the DTI, the STA 100 acquires a transmission opportunity (TXOP) and transmits the Probe response to the AP / PCP 300.

The PCP / AP 300 may transmit by adding a TRN field including the TRN-R subfield to the Probe response in the DTI (see FIG. 31). The STA 100 may switch the receiving sector for each TRN-R subfield in the DTI, receive the TRN-R subfield, and perform training of the receiving sector.

The communication apparatus (STA100) includes a field (DR = 1) indicating a discovery request in the DTI when the A-BFT period is not scheduled (FIGS. 33A and 33B) and when the BFT in the A-BFT period is not completed. The SSW frame is transmitted by changing the transmission sector for each SSW frame. When the communication device (AP / PCP 300) receives an SSW frame including a field (DR = 1) indicating a discovery request, the communication device (AP / PCP 300) transmits a Probe response including information on the BFT result to the communication device (STA 100).

As a result, the communication apparatus (STA 100) performs beamforming even when the communication apparatus (AP / PCP 300) does not transmit the SSW-FB frame or when there is an SSW-FB frame reception error (FIG. 33B). And complete the discovery. Therefore, the period required for discovery can be shortened.

The communication apparatus (STA 100) is ready to start communication with the communication apparatus (AP / PCP 300) by completing beamforming during discovery. Therefore, it is possible to shorten the period required for the procedure until data communication is started.

(Embodiment 3)
In

Embodiments

1 and 2, the STA 100 has shown an example in which active scanning is performed by receiving a DMG beacon transmitted by the AP / PCP 300 (referred to as Discovery Mode = 0). In the third embodiment, a description will be given of a method (discovery mode = 1) in which STA 100 starts beam forming by transmitting a DMG beacon and performs active scanning.

FIG. 35 is a diagram illustrating an example of a procedure according to the third embodiment in which the STA 100 performs an active scan on the AP / PCP 300.

In the BTI, the STA 100 switches the transmission sector for each DMG beacon and transmits a DMG beacon in which the value of the Discovery Mode field is set to 1.

AP / PCP 300 receives the DMG beacon in which the value of the Discovery Mode field is set to 1 in BTI. Further, the reception quality of the received DMG beacon is measured, and the best sector of the STA 100 is selected.

The AP / PCP 300 switches the transmission sector for each SSW frame and transmits the SSW frame during the A-BFT period. The AP / PCP 300 may transmit the information on the best sector of the STA 100 included in the SSW frame.

The STA 100 receives the SSW frame, measures the reception quality of the received SSW frame, and selects the best sector of the AP / PCP 300 based on the measurement result.

When the STA 100 receives the SSW frame in the A-BFT period, the STA 100 transmits the SSW-FB frame in which the discovery request field is set to 1. The STA 100 may include information on the best sector of the AP / PCP 300 in the SSW-FB frame.

When the AP / PCP 300 receives an SSW-FB frame in which the discovery request field is set to 1, it acquires a transmission opportunity (TXOP) and transmits a Probe response to the STA 100.

The STA 100 receives the Probe response and returns an ACK frame to the AP / PCP 300. Thereby, the STA 100 completes the discovery of the AP / PCP 300.

In this way, when performing an active scan with Discovery Mode = 1, the STA 100 transmits an SSW-FB frame including a field (DR = 1) indicating a discovery request. As a result, the STA 100 can receive the Probe response by omitting the transmission of the Probe request, and can shorten the time required for discovery.

FIG. 36 is a flowchart showing an example of a procedure (FIG. 35) in which the STA 100 performs discovery by an active scan with Discovery Mode = 1.

First, the STA 100 starts discovery (S301).

Next, the STA 100 transmits a DMG beacon in which the value of the Discovery Mode field is set to 1 in BTI (S302). That is, the STA 100 may switch the transmission direction of the radio signal (DMG beacon) by switching the transmission sector for each DMG beacon and transmit one or more DMG beacons. In addition, the STA 100 may transmit an information element and a field indicating whether or not an A-BFT period is scheduled after the BTI in a DMG beacon.

On the other hand, if the AP / PCP 300 does not receive the DMG beacon in S302 in the BTI (S303: NO), the flow proceeds to S306. In this case, the AP / PCP 300 does not transmit an SSW frame in S305 described later.

When the AP / PCP 300 receives the DMG beacon of S302 in the BTI (S303: YES), the AP / PCP 300 measures the reception quality of the received DMG beacon and selects the best sector of the STA 100 according to the measurement result (S304).

Next, the AP / PCP 300 transmits the SSW frame to the STA 100 during the A-BFT period (S305). Here, the AP / PCP 300 may switch the transmission sector for each SSW frame and transmit one or more SSW frames. Further, the AP / PCP 300 may transmit the SSW frame including information on the best sector of the STA 100 (for example, the reception quality measured in S303). Then, the flow proceeds to S306.

In S306, when the STA 100 does not receive the SSW frame in the A-BFT period (S306: NO), the STA 100 may return to S302 and retransmit the DMG beacon. If the SSW frame is not received, the AP / PCP 300 does not transmit the SSW frame in S305, and / or the STA 100 receives the SSW frame in S306 due to competition with other STA transmissions or lack of reception sensitivity. The case where it is not received is also included. Note that the STA 100 may end discovery in the current wireless channel or discovery for the AP / PCP 300 when the DMG beacon is retransmitted a predetermined number of times.

In S306, when the STA 100 receives the SSW frame in the A-BFT period (S306: YES), the STA 100 selects the best sector of the AP / PCP 300 and uses the best sector information in the memory for use in communication with the AP / PCP 300. (S307).

Next, the STA 100 transmits an SSW-FB frame in which 1 is set in the field indicating the discovery request (DR = 1) in the A-BFT period (S308). Here, the STA 100 may transmit the SSW-FB frame using the transmission best sector of the STA 100 notified from the AP / PCP 300 by the SSW frame. Further, the STA 100 may include information on the best sector of the AP / PCP 300 in the SSW-FB frame.

On the other hand, when the AP / PCP 300 does not receive the SSW-FB frame of S308 in the A-BFT period (S309: NO), the flow returns to S302, and the AP / PCP 300 waits for reception.

When the AP / PCP 300 receives the SSW-FB frame of S308 in the A-BFT period (S309: YES), the AP / PCP 300 transmits the best sector of the AP / PCP 300 included in the SSW-FB frame for use in communication with the STA 100. Is stored in the memory (S310).

Next, the AP / PCP 300 determines that the BFT between its own AP / PCP 300 and the STA 100 is complete (S311).

Next, when 1 is set (DR = 1) in the field indicating the discovery request in the SSW-FB frame received in S309, the AP / PCP 300 transmits a Probe response to the STA 100 in DTI (S312).

When the STA 100 does not receive the Probe response of S312 in the DTI (S313: NO-1), the flow returns to S312 and the AP / PCP 300 may retransmit the Probe response. Here, when the STA 100 does not receive the Probe response, for example, the case where the STA 100 does not transmit the ACK frame to the AP / PCP 300 is included. Alternatively, when the STA 100 does not receive the Probe response in S313 (S313: NO-2), the flow may return to S302, and the STA 100 may retry transmission of the DMG beacon.

When the STA 100 receives the Probe response in the DTI (S313: YES), the STA 100 transmits an ACK frame to the AP / PCP 300 (S314).

Next, the MAC processor of the STA 100 (see FIG. 8) notifies the host controller of the scan result (for example, the AP / PCP 300 information and reception quality included in the Probe response) (S315).

Then, the STA 100 determines that the discovery of the AP / PCP 300 is completed (S316).

In the third embodiment (FIG. 35), one of the Reserved bits included in the SSW-FB frame of the 11ad standard may be changed to a field indicating a discovery request.

When performing discovery using an active scan of Discovery Mode = 1, the STA 100 includes a field indicating a discovery request in the SSW-FB frame and sets the field value to 1 in step S308 and transmits the field. When the AP / PCP 300 receives the SSW-FB frame including DR = 1, the AP / PCP 300 transmits a Probe response to the STA 100. Accordingly, the STA 100 can complete the discovery of the AP / PCP 300 by omitting the transmission of the Probe request, and can shorten the time required for the discovery.

(Modification of Embodiment 3)
<Modification 3-1>
In FIG. 35, as in FIG. 30, the AP / PCP 300 may transmit a field requesting a Probe response from the STA 100 by including the field in the Probe response. When the STA 100 receives a Probe response including a field requesting a Probe response from the AP / PCP 300, the STA 100 may acquire a transmission opportunity and transmit the Probe response to the AP / PCP 300.

<Modification 3-2>
In the A-BFT period shown in FIG. 35, the STA 100 transmits the field (DR = 1) indicating the discovery request in the frame including the SSW-FB in place of the field indicating the discovery request in the BTI shown in FIG. DR = 1) may be included in the DMG beacon and transmitted.

FIG. 37 is a diagram illustrating an example of a procedure in which the STA 100 performs an active scan on the AP / PCP 300.

The STA 100 transmits a DMG beacon including a field (DR = 1) indicating a discovery request in the BTI.

When the DMG beacon received in the BTI includes DR = 1, the AP / PCP 300 transmits the SSW frame in the A-BFT period, acquires the transmission opportunity (TXOP) after receiving the SSW-FB frame, and acquires the DTI. Then, a Probe response is transmitted to the STA 100.

In Modification 3-1, one of the reserved bits included in the 11ad standard DMG beacon may be changed to a field indicating a discovery request.

As another method, since the DMG beacon is defined as Extensible (extensible) in the 11ad standard, the field indicating the discovery request may be extended and added without using the Reserved bit. As a result, compared with Embodiment 3 (FIG. 35), the Reserved bit of the SSW-FB frame is not reduced, so that the Reserved bit can be secured for future expansion.

<Modification 3-3>
Instead of transmitting the discovery request field (DR = 1) in the SSW-FB frame in the A-BFT period, the STA 100 uses the discovery request field (DR = 1) and the discovery criterion in the BTI. The indicated element (for example, Requested SSID element) may be included in the DMG beacon and transmitted.

FIG. 38 is a diagram illustrating an example of a procedure in which the STA 100 performs an active scan on the AP / PCP 300. In the A-BFT period, the AP / PCP 300 receives the SSW-FB frame, and if the DMG beacon received in the DTI includes DR = 1 and satisfies the discovery criteria, the AP / PCP 300 acquires a transmission opportunity (TXOP) and sends a Probe response. Transmit to STA100.

FIG. 39 is a diagram showing an example of the format of the DMG beacon. In FIG. 39, compared with the 11ad standard DMG beacon field, one Reserved bit of the SSW field is used as the Discovery Request field. When the value of the Discovery Request field is set to 1, the STA 100 may transmit a Requested SSID element not defined in the 11ad standard in a DMG beacon.

The Requested SSID element contains information about the AP / PCP to be discovered. For example, the Requested SSID element includes an SSID field and includes an AP / PCP SSID value. The Requested SSID element may include a Short SSID field.

Further, the STA 100 may transmit the DMG Capabilities element included in the DMG beacon.

Here, even in the 11ad standard, the DMG Capabilities element may be included in the DMG beacon. However, for example, when a STA having a large number of sectors (for example, AP / PCP300) uses the DMG Capabilities element, the radio required for transmitting the DMG beacon. Resource consumption increases and is inefficient.

If the STA 100 has a smaller number of sectors than the AP / PCP 300, the STA 100 may include a DMG Capabilities element in the DMG beacon of Discovery Mode = 1. As a result, an increase in consumption of radio resources is suppressed, and the AP / PCP 300 can omit transmission of a Probe request to the STA 100 in acquiring information about the STA 100 (included in the DMG-Capabilities element).

Note that the STA 100 includes, in the DMG beacon, an element including information (for example, BSS Type, Short SSID, RSN Info in FIG. 23) that restricts the discovery target instead of or in addition to the Requested SSID element. May be sent.

In this way, since the STA 100 transmits the DMG beacon of Discovery Mode = 1 including information related to the discovery criterion, the AP / PCP of the BSS that does not conform to the application or the A / BFT period from the AP / PCP that is not specified Response can be avoided. Therefore, contention in the A-BFT period can be avoided, and an increase in discovery time due to, for example, an SSW frame reception failure can be suppressed.

<Modification 3-4>
In the A-BFT period, the AP / PCP 300 includes a field indicating whether or not to support a response to the field indicating the discovery request (DR = 1) in the SSW-FB frame transmitted by the STA 100 in the SSW frame. May be.

FIG. 40 is a diagram illustrating an example of a procedure in which the STA 100 performs an active scan on the AP / PCP 300.

In the A-BFT period, the AP / PCP 300 includes a field (DRS: Discovery Request Supported) indicating whether to support a response to the field indicating the discovery request (DR = 1) in the SSW-FB frame transmitted by the STA 100, It is included in the SSW frame and transmitted.

When the value of the DRS field of the received SSW frame is 1, the STA 100 sets the discovery request field to 1 (DR = 1) during the A-BFT period, transmits the SSW-FB frame, and waits for a Probe response. I do.

When the value of the DRS field of the received SSW frame is 0 (not shown), the STA 100 sets the field indicating the discovery request to 0 (DR = 0) in the A-BFT period, and transmits the SSW-FB frame. Instead of waiting for a Probe response, for example, a Probe request is transmitted to the AP / PCP 300.

The STA 100 can determine whether or not to wait for a Probe response after transmitting the SSW-FB frame according to the DRS value included in the SSW frame, thereby avoiding unnecessary waiting and reducing the time required for discovery. .

<Modification 3-5>
The STA 100 may transmit the SSW-FB frame including the discovery request field (DR = 1) set to 1 with the control trailer added during the A-BFT period. The control trailer may use the format shown in FIG. 23 as an example, and a description thereof is omitted here.

FIG. 41 is a diagram illustrating an example of a procedure in which the STA 100 performs an active scan on the AP / PCP 300.

AP / PCP 300 receives the SSW-FB frame with the control trailer added during the A-BFT period. The AP / PCP 300 transmits a Probe response in the DTI when the discovery criterion indicated by the value of the control trailer is compatible with the AP / PCP 300 (for example, when the value of Short SSID matches or the value of BSS Type matches). Also good.

As described above, the STA 100 transmits the SSW-FB frame with the control trailer including information on the discovery standard added. Therefore, for example, it is possible to avoid transmission of a Probe response by an AP / PCP of a BSS that does not conform to an application or an AP / PCP that is not specified, and the occurrence of interference with other STAs (not shown) can be reduced.

Compared to sending an unnecessary Probe response, the addition of a control trailer to the SSW-FB frame consumes less radio resources and is more efficient.

As described above, the communication apparatus (STA) 100 transmits a field indicating a discovery request included in the SSW-FB frame when performing an active scan of Discovery Mode = 1. As a result, the STA 100 can omit the transmission of the Probe request, and can avoid the occurrence of backoff or retransmission processing with a large delay, thereby avoiding an increase in time required for discovery.

(Embodiment 4)
In the second embodiment, when the STA does not perform BFT (SSW frame transmission) in the A-BFT period and when the STA performs BFT (SSW frame transmission) in the A-BFT period, The case where the STA 100 performs the sector sweep in the DTI when the AP / PCP did not receive the SSW frame due to transmission competition or the like, or when a reception error has occurred has been described. In the fourth embodiment, a case where the STA 100 transmits a DMG beacon of Discovery Mode = 1 will be described as an example of the DTI sector sweep of the second embodiment.

FIG. 42 is a diagram illustrating an example of a procedure in which the STA 100 performs an active scan on the AP / PCP 300.

42, the AP / PCP 300 transmits a DMG beacon that does not include DR = 1 while changing the transmission sector for each DMG beacon.

42. In the BTI of FIG. 42, the STA 100 receives a DMG beacon. Another STA (STA 200 not shown) may receive the DMG beacon in the same BTI.

When the STA 100 does not perform BFT (SSW frame transmission) during the A-BFT period, and when the STA 100 performs BFT (SSW frame transmission) during the A-BFT period, the AP / PCP 300 communicates with other STAs. If the SSW frame is not received due to transmission competition or the like, or if a reception error occurs in the AP / PCP 300, the AP / PCP 300 omits sending the SSW-FB frame and applies the following procedure. May be.

Also, when the STA 100 transmits an SSW frame that does not include DR = 1 in the A-BFT period and the AP / PCP 300 transmits an SSW-FB frame, but the STA 100 cannot receive, the following procedure is applied. May be.

The STA 100 changes the transmission sector for each DMG beacon and transmits a DMG beacon including a field (DR = 1) indicating a discovery request. The STA 100 transmits the DMG beacon including the best sector of the AP / PCP 300.

FIG. 43 is a diagram showing an example of the format of the DMG beacon. The DMG beacon includes, for example, an SSW field and a DiscoveryDisRequest field.

Also, the DMG beacon includes a Beamforming Feedback element. The Beamforming Feedback element includes a field for identifying the element (for example, Element ID, Length, Element ID Extension field), a MAC address field indicating the MAC address of the AP / PCP 300, and an SSW Feedback field including beamforming feedback information.

The SSW Feedback field may include the same subfield as the 11SW standard SSW Feedback field. For the description of the subfield, the description of FIG. 4 may be referred to. Therefore, the description here is omitted.

STA 100 includes a Beamforming Feedback element in a DMG beacon of Discovery Mode = 1. Thereby, the STA 100 can notify beamforming feedback information (for example, the contents of the SSW Feedback field) of the STA (for example, the AP / PCP 300) indicated by the MAC address field.

FIG. 44 is a diagram showing another example of the format of the DMG beacon. 44, unlike FIG. 43, the Discovery Request field is included in the SSW Feedback field of the Beamforming Feedback element. As a result, the format of the SSW Feedback field becomes the same as that in FIG.

In the DTI of FIG. 42, the AP / PCP 300 receives the DMG beacon including the discovery request field (DR = 1) and the best sector information, and based on the received best sector information for communication with the STA 100, Set the transmit antenna to the best sector.

AP / PCP 300 transmits a Probe response to STA 100 in DTI. The STA 100 receives the Probe response and completes the discovery.

When the STA 100 receives the DMG beacon from the AP / PCP 300 in the BTI and does not complete the BFT in the A-BFT period, the DMG beacon including a field (DR = 1) indicating the discovery request including the best sector information in the DTI Send. Thereby, the AP / PCP 300 can acquire the information of the best sector in the DTI, can omit the transmission of the SSW frame and the reception of the SSW-FB frame (see Embodiment 3), and can transmit the Probe response.

Thereby, even when the STA 100 does not complete the BFT in the A-BFT period for the AP / PCP 300, it is possible to avoid an increase in time required for discovery.

FIG. 45 is a flowchart illustrating an example of a procedure in which the STA 100 performs discovery. The same processes as those in FIG. 7 (Embodiment 1) are assigned the same numbers, and explanations are omitted.

First, the STA 100 starts discovery (S001). Next, the STA 100 receives a DMG beacon in BTI (S002).

If the A-BFT period is not scheduled (S403: NO-1), the STA 100 proceeds to S421 in order to transmit a DMG beacon of Discovery Mode = 1. The description of S421 will be described later. As in the first embodiment, the STA 100 may return to S002 to wait for the next BTI (see S403: NO-2 in FIG. 45 and DTI in FIG. 42).

Next, when the A-BFT period is scheduled (S403: YES), the STA 100 transmits an SSW frame (S404). Here, unlike the case of S004 in FIG. 7, the STA 100 does not set DR = 1 in the SSW frame (see the A-BFT period in FIG. 2).

When the AP / PCP 300 has not received the SSW frame in S404 (S405: NO-1), the flow returns to S002 (see the A-BFT period in FIG. 2). In this case, the SSW-FB frame (and the Probe response in S012) is not transmitted to the STA 100. Here, the case where the SSW frame is not received includes the case where there is a reception error or the case where the reception power is lower than a predetermined value. Alternatively, when the AP / PCP 300 does not receive the SSW frame of S404 (S405: NO-2), the flow may move to S421 described later.

When the AP / PCP 300 receives the SSW frame in S404 (S405: YES), the AP / PCP 300 determines the best sector based on the SSW frame (S406). Next, the AP / PCP 300 transmits the SSW-FB frame to the STA 100 (S407) (see the A-BFT period in FIG. 2). Then, the flow proceeds to S408.

In S408, when the STA 100 does not receive the SSW-FB frame from the AP / PCP 300 (S408: NO), the STA 100 proceeds to S421 to transmit a DMG beacon of DiscoveryDisMode = 1 (the A-BFT period in FIG. 2). See).

In S421, the STA 100 changes the transmission sector for each DMG beacon and transmits a DMG beacon of DiscoveryDisMode = 1 (S421) (see DTI in FIG. 42). Note that the STA 100 may transmit the DMG beacon of Discovery Mode = 1 including the best sector information of the AP / PCP 300 based on the reception quality of the DMG beacon of the AP / PCP 300 received in S002. In addition, the STA 100 may include scheduling information in the DMG beacon and set a BTI, A-BFT period, and DTI that are different from the scheduling (time) set in the DMG beacon by the AP / PCP 300.

On the other hand, the AP / PCP 300 receives the DMG beacon in S421, and stores the best sector information included in the DMG beacon in the memory for communication with the STA 100 (S422). This completes the BFT between the STA 100 and the AP / PCP 300 (see DTI in FIG. 42). Then, the AP / PCP 300 omits the transmission of the SSW frame and proceeds to S435 (see the DTI in FIG. 42). This point is different from the case of the third embodiment.

In S408, when the STA 100 receives the SSW-FB frame from the AP / PCP 300 (S408: YES), it stores the information of the best sector included in the SSW-FB frame in the memory (S431). Then, the STA 100 determines that the initial BFT between the AP / PCP 300 and its own STA 100 is completed (successful) (S432). The processes of S432 and S432 are the same as the processes of S009 and S010 of FIG. 7, respectively.

Next, the STA 100 transmits a Probe request to the AP / PCP 300 in DTI (S433).

On the other hand, if the AP / PCP 300 receives the Probe request and there is no reception error, the AP / PCP 300 transmits an ACK frame after SIFS (3 μsec) (S434). The process of S434 is the same as the process of S011 of FIG. Then, the flow proceeds to S435.

In S435, the AP / PCP 300 transmits a Probe response to the STA 100 (S435). Note that the AP / PCP 300 may measure the reception quality of the DMG beacon in S422 to determine the best sector of the STA 100, and may include the best sector information of the STA 100 in the Probe response in S012 (see the DTI in FIG. 42). ).

On the other hand, the STA 100 receives the Probe response in S435 and transmits an ACK frame to the AP / PCP 300 after SIFS (3 μsec) (S436).

Next, the STA 100 stores the scan result included in the Probe response in S436 in the memory (S437). The process of S437 is the same as the process of S015 of FIG.

Then, the STA 100 completes discovery for the AP / PCP 300 (S438). The process of S438 is the same as the process of S016 of FIG.

(Modification of Embodiment 4)
<Modification 4-1>
42, the AP / PCP 300 may receive a DMG beacon including a field indicating a discovery request (DR = 1) in the DTI, and may transmit a field indicating that a response is possible in the DTI included in the DMG beacon. .

<Modification 4-2>
If the STA 100 has acquired the best sector information for a plurality of AP / PCPs (not shown), a plurality of Beamforming Feedback elements may be included in the DMG beacon in the DTI. According to the procedure described later, the STA 100 can shorten the delay for acquiring Probe responses related to a plurality of AP / PCPs, and can complete the active scan early.

<Modification 4-3>
The STA 100 may transmit an element indicating a discovery criterion included in the DMG beacon in the DTI (see Modification 3-2 of Embodiment 3).

<Modification 4-4>
The STA 100 may transmit a DMG beacon including a field or subfield indicating the type of discovery request in the DTI (see Modification 1-2 of Embodiment 1, FIG. 13). In addition, the AP / PCP 300 may transmit additional information according to the type of discovery request in the Probe response in the DTI.

<Modification 4-5>
Note that the STA 100 may transmit a DMG beacon including a field indicating the number of TRN-R subfields or a subfield in the DTI (see FIGS. 14 and 15).

When the AP / PCP 300 receives a DMG beacon including a field (DR = 1) indicating a discovery request and including a field or subfield in which the number of TRN-R subfields is 1 or more, the TRN-R subfield is received in the DTI. A Probe response to which is added may be transmitted.

<Modification 4-6>
Note that the PCP / AP 300 may transmit information requesting a Probe response from the STA 100 in the DTI by including it in the Probe response (see FIG. 30).

<Modification 4-7>
In the DTI, the PCP / AP 300 uses information related to the BSS (for example, DMG Capabilities of the AP / PCP 300 that is information included in the Probe response, information necessary for the STA 100 to complete discovery) instead of the Probe response in FIG. An included DMG beacon may be transmitted.

FIG. 46 is a diagram illustrating an example of a procedure in which the STA 100 performs discovery.

In the DTI, the PCP / AP 300 transmits a DMG beacon including information related to the BSS instead of the Probe response in the DTI of FIG. The DMG beacon may include all or part of the elements included in the Probe response.

The STA 100 acquires information used for discovery of the AP / PCP 300 by receiving the DMG beacon transmitted by the AP / PCP 300 in the DTI, and completes the discovery.

Also, other STAs (not shown) receive the DMG beacon transmitted by the AP / PCP 300 in the DTI, thereby omitting the DMG beacon transmission from the AP / PCP 300 in the BTI to the DMG beacon transmitted by the STA 100 in the DTI. You may complete the discovery.

In the BTI, the AP / PCP 300 may not include all BSS information in the DMG beacon to be transmitted (may be partially included), and may include all BSS information in the DMG beacon transmitted in the DTI.

Here, since the AP / PCP 300 repeatedly transmits the DMG beacon in the BTI for each BI (that is, because the number of transmissions is large), the consumption of many radio resources can be suppressed by not including information on all the BSSs. .

In addition, since transmission of DMG beacons in DTI is performed when a DMG beacon of DiscoveryDisMode = 1 is received, unnecessary transmission of DMG beacons is suppressed and radio resources can be used efficiently. For example, transmission of a DMG beacon including information related to the BSS when there is no STA performing discovery can be avoided.

As described above, when the STA 100 receives the DMG beacon from the AP / PCP 300 in the BTI and does not complete the BFT in the A-BFT period, the STA 100 indicates the discovery request including the best sector information in the DTI. A DMG beacon including (DR = 1) is transmitted. As a result, the AP / PCP 300 can acquire the best sector information, omits the transmission of the SSW frame and the reception of the SSW-FB frame (see Embodiment 3) in the A-BFT period, and transmits the Probe response in the DTI. it can.

In the DTI, when the AP / PCP 300 receives a DMG beacon including a field (DR = 1) indicating a discovery request, the probe response is transmitted by omitting the transmission of the SSW frame in the DTI. Thereby, it is possible to avoid an increase in interference with other STAs (not shown) due to transmission of the SSW frame in the DTI.

(Embodiment 5)
In the third embodiment, the STA 100 transmits a field (DR = 1) indicating a discovery request in the BTI by including it in the DMG beacon of Discovery Mode = 1, and the AP / PCP 300 transmits the BFT in the A-BFT period. In the case of completion, the procedure for transmitting a Probe response in the DTI has been described. In the present embodiment, AP / PCP 300 transmits a shortened information related to the BSS in the SSW frame and the Short SSW packet in the A-BFT period instead of the Probe response, and reduces the discovery time in STA 100. explain.

FIG. 47 is a diagram illustrating an example of a procedure of the fifth embodiment in which the STA 100 performs an active scan on the AP / PCP 300.

In the DTI, the STA 100 transmits a field indicating a discovery request (DR = 1) in a DMG beacon of DiscoveryDisMode = 1.

AP / PCP 300 receives the DMG beacon in DTI.

When the AP / PCP 300 receives a discovery-mode = 1 DMG beacon including a discovery request field (DR = 1) in the BTI, the AP / PCP 300 transmits the short information about the BSS to the SSW frame and the Short-SSW packet in the A-BFT period. To be included and sent. In FIG. 47, the AP / PCP 300 transmits a Short SSW packet.

FIG. 48 is a diagram illustrating an example of a format of a Short SSW packet including shortened information related to the BSS. Note that the description of the same fields and subfields as in FIG. 23 is omitted.

The Short SSW packet includes a control trailer, and the control trailer includes, for example, a Reduced Discovery Information field.

The Reduced Discovery Information field includes information necessary for the STA 100 to complete discovery, for example, BSS Type, Short SSID, RSN Info, and Reduced Capabilities fields.

The Reduced Capabilities field includes, for example, information necessary for performing initial connection (Association, Authentication) after the STA 100 completes discovery. For example, the authentication procedure and security algorithm type supported by the AP / PCP 300 are included.

The Reduced Capabilities field includes, for example, a DMG Privacy field, an ECAPC (Extended centralized access point, or personal, basic service, set control, point cluster, and Policy fields.

The STA 100 receives the Short SSW packet including the shortened information related to the BSS in the A-BFT period of FIG.

The STA 100 determines whether or not to transmit a Probe request based on the received shortened information regarding the BSS. For example, since the Reduced Capabilities field does not include all information related to the AP / PCP 300, when the information related to the function used by the STA 100 is not included in the Reduced Capabilities field, it is determined that the Probe request is transmitted in the DTI.

Also, for example, the Reduced Capabilities field includes a bit indicating whether or not the AP / PCP 300 supports each optional function regarding a plurality of optional functions of the AP / PCP 300, but does not include a parameter regarding each optional function.

For this reason, the STA 100 may use an optional function supported by the AP / PCP 300, and may transmit a Probe request to the AP / PCP 300 in the DTI when an additional parameter related to the optional function is insufficient.

The STA 100 can acquire additional parameters related to optional functions by receiving the Probe response from the AP / PCP 300.

Note that if the STA 100 does not use the optional function supported by the AP / PCP 300, or if the optional function is used and additional parameters related to the optional function are satisfied, the STA 100 omits sending the Probe request to the AP / PCP 300. Also good. The STA 100 may determine whether to send a Probe request to the AP / PCP 300 according to the type of the optional function to be used.

The STA 100 may transmit the SSW-FB frame to the AP / PCP 300 when receiving the SSW frame and the Short SSW packet in the A-BFT period.

When the AP / PCP 300 receives a discovery-mode = 1 DMG beacon including a discovery request field (DR = 1) in the BTI, the AP / PCP 300 transmits a Short-SSW packet including shortened information regarding the BSS in the A-BFT period. In addition, since the Probe response is not transmitted, the STA 100 can reduce the delay required for discovery. Further, since AP / PCP 300 does not transmit a Probe response, it is possible to reduce interference given to other STAs.

In addition, since the STA 100 determines whether or not to transmit a Probe request in the DTI based on the shortened information related to the BSS, the transmission of unnecessary Probe requests is reduced, the delay required for discovery is shortened, and other STAs are notified. The interference given can be reduced.

FIG. 49 is a flowchart illustrating an example of a procedure in which the STA 100 performs discovery by an active scan with Discovery Mode = 1. The same processes as those in FIG. 36 of the third embodiment are given the same numbers, and the description thereof is omitted.

First, the STA 100 starts discovery (S301).

Next, the STA 100 transmits a DMG beacon in which the value of the Discovery Mode field is set to 1 in BTI (S302).

When the AP / PCP 300 does not receive the DMG beacon at S302 in the BTI, or when there is another reason (for example, when interference is detected) (S303: NO), the flow proceeds to S506 described later. In this case, the AP / PCP 300 omits transmission of the Short SSW frame in S505 described later.

When the AP / PCP 300 receives the DMG beacon in S302 in the BTI (S303: YES), the AP / PCP 300 selects the best sector (S304). Then, the AP / PCP 300 transmits a Short SSW packet to the STA 100 in the A-BFT period (S505). Note that the AP / PCP 300 may switch the transmission sector for each Short SSW packet and transmit the Short SSW packet. Further, the AP / PCP 300 may transmit the information of the best sector (for example, measured by the DMG beacon in S303) of the STA 100 in the Short SSW packet. Further, when the AP / PCP 300 receives a DMG beacon including a discovery request field (DR = 1) in the BTI, the AP / PCP 300 may add a control trailer to the Short SSW packet and transmit the BSS including shortened information. Good.

If the STA 100 does not receive the Short SSW packet of S505 in the A-BFT period (S506: NO), the flow returns to S302, and the STA 100 may retry transmission of the DMG beacon. If the Short SSW packet is not received here, the AP / PCP 300 does not transmit the Short SSW packet in S505, and / or due to contention with other STA transmissions or lack of reception sensitivity. The case where the STA 100 does not receive the Short SSW packet may be included. Note that, when the STA 100 performs a predetermined number of trials, the STA 100 may end the discovery of the corresponding wireless channel and the AP / PCP 300.

When the STA 100 receives the Short SSW packet during the A-BFT period (S506: YES), the STA 100 selects the best sector of the AP / PCP 300 and stores the information of the best sector in the memory for future use with the AP / PCP 300. To store. Also, the STA 100 determines whether or not to transmit a Probe request based on the shortened information regarding the BSS included in the control trailer of the Short SSW packet (S507). In S507, when the STA 100 determines not to transmit the Probe request, the flow may proceed to S517 and complete the discovery.

The STA 100 transmits the SSW-FB frame to the AP / PCP 300 (S508).

On the other hand, when the AP / PCP 300 receives the SSW-FB frame in S508 (S509: YES), the AP / PCP 300 stores the information of the transmission best sector included in the SSW-FB frame in the memory (S510). If the AP / PCP 300 does not receive the SSW-FB frame in S508, the flow may return to S302 (S509: NO-1). Alternatively, in this case, the flow may proceed to S517 to complete discovery (S509: NO-2).

Next, the AP / PCP 300 determines that the BFT between its own AP / PCP 300 and the STA 100 has been completed (S511).

On the other hand, if the STA 100 determines to transmit the Probe request in S507 (S5121: NO), the STA 100 transmits the Probe request to the AP / PCP 300 (S512-2), and the flow proceeds to S513. Note that if the STA 100 determines in S507 that transmission of the Probe request is omitted, the processing of S512-2 is not performed (S5121: YES), and the flow proceeds to S517 and the discovery is completed.

Meanwhile, the AP / PCP 300 receives the Probe request in S512 and transmits an ACK frame to the STA after SIFS (S513).

Next, the AP / PCP 300 transmits a Probe response to the STA 100 (S514).

On the other hand, the STA 100 receives the Probe response in S514, and transmits an ACK frame to the AP / PCP 300 after SIFS (S515).

Next, the MAC processor of the STA 100 (see FIG. 8) notifies the host controller of the scan result (for example, the AP / PCP 300 information and reception quality included in the Probe response) (S516).

Then, the STA 100 completes the discovery of the AP / PCP 300 (S517).

FIG. 50 is a block diagram showing an example of the configuration of the communication devices (AP / PCP 300 and STA 100). The description of the same components as those in FIG. 32 is omitted.

The MAC processor includes a control trailer message generation circuit and a control trailer message processing circuit.

In the A-BFT period, the control trailer message generation circuit of the AP / PCP 300 generates shortened information related to the BSS based on the information related to the BSS (for example, input from the host controller), and the data of the control trailer (see FIG. 48). Is input to the PHY transmission circuit. The PHY transmission circuit encodes and / or modulates the data of the control trailer, adds it to the ShorthorSSW packet, and transmits it.

In the A-BFT period, the STA 100 receives the Short SSW packet to which the control trailer is added, and the PHY receiver circuit demodulates and / or decodes the Short SSW packet body and the control trailer, and the Short SSW data and control Trailer data is generated and input to the MAC processor. The control trailer message processing circuit generates shortened information regarding the BSS from the data of the control trailer and outputs it to the host.

When the message generation circuit determines to transmit a Probe response based on the received shortened information regarding the BSS, it generates Probe request data and inputs it to the PHY transmission circuit.

The HOST receives the shortened information related to the received BSS and the probe response information (Probe request) as a result of discovery.

(Modification of Embodiment 5)
<Modification 5-1>
The STA 100 may include in the DMG beacon a field indicating whether to support reception of a Short SSW packet to which a control trailer including shortened information related to the BSS is added in the BTI.

<Modification 5-2>
In the AP / PCP 300, information included in the control trailer in the A-BFT period may be discovery information defined in FILS (First Initial Link Setup Standard, IEEE802.11ai).

<Modification 5-3>
In the A-BFT period, the STA 100 may transmit the field (DR = 1) including the discovery request included in the SSW-FB frame, as in FIG. When the STA 100 determines that the probe request needs to be transmitted, the STA 100 may transmit the field (DR = 1) including the discovery request by including it in the SSW-FB frame.

When the AP / PCP 300 receives the SSW-FB frame including the field (DR = 1) including the discovery request, the AP / PCP 300 transmits a Probe response to the STA 100 in the DTI.

When the STA 100 determines to transmit the Probe request, the STA 100 includes a field (DR = 1) including the discovery request in the SSW-FB frame in the A-BFT period instead of transmitting the Probe request. Thus, the Probe response from the AP / PCP 300 may be received.

<Modification 5-4>
The STA 100 may determine that the AP / PCP 300 is not a discovery target based on the shortened information regarding the BSS received in the A-BFT period, and may stop transmitting the Probe request. For example, the BSS Type is not compatible with the BSS Type corresponding to the application used by the STA 100.

As described above, when the AP / PCP 300 receives a DMG beacon of Discovery Mode = 1 including a field (DR = 1) indicating a discovery request in the BTI, the AP / PCP 300 includes the short information regarding the BSS. An SSW packet is transmitted and transmission of a Probe response is omitted. As a result, the STA 100 can shorten the delay required for discovery. Further, since the AP / PCP 300 omits the transmission of the Probe response, the interference given to other STAs can be reduced.

Further, the STA 100 determines whether or not to transmit a Probe request based on the shortened information regarding the BSS received during the A-BFT period. Thereby, transmission of unnecessary Probe requests can be reduced, a delay required for discovery can be shortened, and interference given to other STAs can be reduced.

(Embodiment 6)
When the AP / PCP 300 receives an SSW frame including DR = 1 in the A-BFT period, the AP / PCP 300 transmits a Probe response in the first embodiment. In the sixth embodiment, the AP / PCP 300 transmits a control trailer (implemented in the SSW-FB frame). (Similar to the one added to the Short SSW in the form 5) is transmitted and the discovery of the STA 100 is completed early.

FIG. 51 is a diagram illustrating an example of a procedure in which the STA 100 performs an active scan.

In the BTI, the AP / PCP 300 switches the transmission sector for each DMG beacon and transmits the DMG beacon.

The STA 100 receives the DMG beacon in the BTI and determines the best sector of the AP / PCP 300.

In the A-BFT period, the STA 100 transmits an SSW frame including the best sector information of the AP / PCP 300 and a field (DR = 1) indicating a discovery request.

The AP / PCP 300 receives the SSW frame and determines the best sector of the STA 100.

In the A-BFT period, the AP / PCP 300 includes the information on the best sector of the STA 100 in the SSW-FB frame, and transmits it by adding a control trailer. The control trailer includes shortened information regarding the BSS (see FIG. 48).

The STA 100 receives the SSW-FB frame with the control trailer added during the A-BFT period. The control trailer is demodulated and / or decoded to obtain shortened information about the BSS.

The STA 100 determines whether to request the probe response information from the AP / PCP 300 based on the shortened information regarding the BSS. That is, it is determined whether or not to transmit a Probe request frame.

When the STA 100 receives the DMG beacon from the AP / PCP 300 in the BTI, the STA 100 acquires the shortened information about the BSS by using the SSW-FB frame before performing the probe exchange (transmitting the probe request frame and receiving the probe response). , It is determined whether the AP / PCP 300 is a discovery target AP / PCP. Therefore, since unnecessary probe exchange is not performed, the delay required for discovery can be shortened, and interference with other STAs (not shown) can be suppressed.

Note that the STA 100 may transmit the SSW frame without including DR = 1 in the A-BFT period. The AP / PCP 300 may transmit the SSW-FB frame with the control trailer added during the A-BFT period regardless of whether or not DR = 1 is included in the received SSW frame.

The STA (for example, the STA 100) corresponding to the reception of the control trailer demodulates and / or decodes the control trailer, and acquires the shortened information regarding the BSS. An STA (not shown) that does not support reception of the control trailer receives the SSW-FB frame and discards the control trailer.

Note that the STA 100 may transmit a Short SSW packet instead of the SSW frame in the A-BFT period. When the AP / PCP 300 receives the SSW frame including DR = 1 and the Short SSW packet, the AP / PCP 300 determines that the transmission source STA (for example, the STA 100) supports reception of the control trailer, and sets the control trailer in the SSW-FB frame. It may be added and transmitted. When the AP / PCP 300 receives an SSW frame that does not include DR = 1, the AP / PCP 300 determines that the transmission source STA (for example, another STA (not shown)) does not support reception of the control trailer, and adds the control trailer to the SSW-FB frame. You may send without adding.

As described above, backward compatibility with the 11ad standard is maintained.

FIG. 52 is a flowchart illustrating an example of a procedure in which the STA 100 performs discovery. The same processing as in FIG. 7 (Embodiment 1) may be assigned the same number and description thereof may be omitted.

First, the STA 100 starts discovery (S001), and executes the same processing as S002 to S004 in FIG.

When the AP / PCP 300 receives the SSW frame including the field indicating the discovery request (DR = 1) (S005: YES), the AP / PCP 300 transmits the SSW-FB frame to which the control trailer is added to the STA 100 (S607) (FIG. 51). (See A-BFT period). Note that the AP / PCP 300 may transmit the SSW-FB frame using the best sector notified by the SSW frame. Further, the AP / PCP 300 may transmit the information on the best sector of the STA 100 by including it in the SSW-FB frame.

On the other hand, when the STA 100 receives the SSW-FB frame in S607 (S608: YES), the STA 100 stores the best sector information included in the SSW-FB frame in the memory in preparation for communication with the AP / PCP 300 (FIG. 51). (See A-BFT period). Further, when the STA 100 receives the SSW-FB frame including the control trailer, the STA 100 determines whether or not to transmit the Probe request based on the shortened information regarding the BSS included in the control trailer (S609) (A- in FIG. 51). See BFT period).

Then, the STA 100 determines that the initial BFT between the AP / PCP 300 and its own STA 100 is completed (successful) (S610).

Next, if the STA 100 determines to transmit a Probe request in S609 (S611-1: NO), the STA 100 transmits a Probe request to the AP / PCP 300 in the DTI (S611-2) (see the DTI in FIG. 2). The flow proceeds to S612. If the STA 100 determines not to transmit a Probe request in S609 (S611-1: YES), the flow proceeds to S616, and the discovery of the AP / PCP 300 may be completed (see DTI in FIG. 51).

Meanwhile, the AP / PCP 300 receives the Probe request in S612 in the DTI, and transmits an ACK frame to the STA 100 after SIFS (S612) (see the DTI in FIG. 2).

Next, the AP / PCP 300 transmits a Probe response to the STA 100 in DTI (S613).

On the other hand, the STA 100 receives the Probe response of S613 in the DTI, and transmits an ACK frame to the AP / PCP 300 after SIFS (S614).

Next, the STA 100 stores the scan result included in the Probe response in the memory (S615).

Then, the STA 100 completes discovery for the AP / PCP 300 (S616). Note that the STA 100 may perform discovery for another AP / PCP (not shown), and may return to S001 by repeating the discovery by repeating the same radio channel or switching the radio channel.

(Modification of Embodiment 6)
The AP / PCP 300 adds information indicating whether or not to support transmission of the SSW-FB frame including the shortened information related to the BSS (see the A-BFT period in FIG. 51) with the addition of the control trailer (see BTI in FIG. 51). ).

Note that in the A-BFT period of FIG. 51, the STA 100 may include DR = 1 in the SSW frame.

51. In the A-BFT period of FIG. 51, the STA 100 may include a field indicating that the Probe response of the first embodiment is requested in the SSW frame. In addition, the STA 100 requests a field indicating whether to request either the Probe response of the first embodiment or the shortened information related to the BSS included in the control trailer of the sixth embodiment or not to the SSW frame. May be included.

Note that, in the A-BFT period of FIG. 51, the STA 100 may transmit a Short SSW packet instead of the SSW frame.

The information that the AP / PCP 300 includes in the control trailer in the SSW-FB frame in the A-BFT period of FIG. It may be.

The STA 100 may determine that the AP / PCP 300 is not a discovery target based on the shortened information regarding the BSS received during the A-BFT period, and may stop transmitting the Probe request. For example, this is a case where the BSS Type does not match the BSS 応じ Type corresponding to the application used by the STA 100.

As described above, when the AP / PCP 300 receives an SSW frame including a field (DR = 1) indicating a discovery request in the A-BFT period, the SSW-FB to which the control trailer including the shortened information regarding the BSS is added. Send a frame. As a result, the STA 100 can acquire the shortened information regarding the BSS before performing the probe exchange, and determine whether the AP / PCP 300 is the discovery target AP / PCP. Therefore, since unnecessary probe exchange is not performed, the delay required for discovery can be shortened, and interference with other STAs (not shown) can be suppressed.

The embodiment has been described above.

Each functional block used in the description of the above embodiment is typically realized as an LSI which is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them. The name used here is LSI, but it may also be called IC, system LSI, super LSI, or ultra LSI depending on the degree of integration.

Further, the method of circuit integration is not limited to LSI, and implementation with a dedicated circuit or a general-purpose processor is also possible. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

Furthermore, if integrated circuit technology that replaces LSI emerges as a result of advances in semiconductor technology or other derived technology, it is naturally also possible to integrate functional blocks using this technology. Biotechnology can be applied.

This patent application claims priority from US Patent Application No. 62 / 430,251 filed on December 5, 2016, the entire contents of which are hereby incorporated by reference. Incorporated into.

One aspect of the present disclosure is suitable for a communication system compliant with a Wi-Fi standard to be created in the future, for example, the IEEE 802.11ay standard.

100,200 STA
300 AP / PCP

Claims

A wireless communication method for a wireless communication device, comprising:
One or more beacon frames are transmitted during the beacon transmission period;
Receiving one or more transmission sector sweep frames from other wireless communication devices in a beamforming training period after the beacon transmission period;
If the one or more transmission sector sweep frames include information about a discovery request, the information about the first transmission sector selected by the other wireless communication device is extracted from the one or more transmission sector sweep frames;
Selecting a second transmission sector from transmission sectors used by the other wireless communication devices included in the received one or more transmission sector sweep frames;
A feedback frame including information on the selected second transmission sector is transmitted using the first transmission sector in the beamforming training period;
In the data transmission period after the beamforming training period, a probe response frame including information on the selected second transmission sector is transmitted using the first transmission sector.
Wireless communication method.
The wireless communication device
Changing the transmission sector for transmitting each beacon frame for each beacon frame;
The wireless communication method according to claim 1.
The wireless communication device
Determining another wireless communication device to which the feedback frame is to be transmitted, based on the information on the selected first transmission sector;
The wireless communication method according to claim 1.
The first transmission sector is:
Selected based on the reception quality of the beacon frame in the other wireless communication device,
The wireless communication method according to claim 3.
The second transmission sector is:
Selected based on the reception quality of the transmission sector sweep frame in the wireless communication device;
The wireless communication method according to claim 1.
A wireless communication method for a wireless communication device, comprising:
Receiving one or more beacon frames from other wireless communication devices in a beacon transmission period;
Selecting a first transmission sector from information regarding the transmission sector of the wireless communication device included in the one or more beacon frames;
Transmitting one or more transmission sector sweep frames including information regarding the selected first transmission sector and information regarding a discovery request to another wireless communication device;
A feedback frame including information on the second transmission sector selected by the other wireless communication device transmitted from the other wireless communication device in the beamforming training period after the beacon transmission period, and the beamforming training period Receiving at least one frame of a probe response frame including information on the second transmission sector transmitted from the other wireless communication device in a later data transmission period;
Using the information about the second transmission sector included in the received at least one frame to transmit data to the other wireless communication device;
Wireless communication method.
The wireless communication device
Changing the transmission sector for transmitting each transmission sector sweep frame for each transmission sector sweep frame;
The wireless communication method according to claim 6.
The first transmission sector is:
Selected based on the reception quality of the one or more beacon frames in the wireless communication device;
The wireless communication method according to claim 6.
The second transmission sector is:
Based on the reception quality of the one or more transmission sector sweep frames in the other wireless communication device,
Selected,
The wireless communication method according to claim 6.
A wireless communication device comprising a transmission circuit, a reception circuit, and a MAC processing circuit,
The transmission circuit includes:
One or more beacon frames are transmitted during the beacon transmission period;
Transmitting one or more feedback frames using a second transmission sector in a beamforming training period after the beacon transmission period;
In a data transmission period after the beamforming training period, a probe response frame is transmitted using a second transmission sector,
The receiving circuit is
Receiving one or more transmission sector sweep frames from other wireless communication devices during the beamforming training period;
The MAC processing circuit
When the received one or more transmission sector sweep frames include information on a discovery request,
Extracting information on a first transmission sector selected by the other wireless communication device included in the received one or more transmission sector sweep frames;
Selecting the second transmission sector from transmission sectors used by the other wireless communication devices included in the received one or more transmission sector sweep frames;
Generating a feedback frame including information about the selected second transmission sector and a probe response frame including information about the selected second transmission sector;
Wireless communication device.
A wireless communication device comprising a receiving circuit, a MAC processing circuit, and a transmitting circuit;
The receiving circuit is
In the beacon transmission period, one or more beacon frames are received from other wireless communication devices,
A feedback frame including information on the second transmission sector selected by the other wireless communication device transmitted from the other wireless communication device in the beamforming training period after the beacon transmission period, and the beamforming training period Receiving at least one frame of a probe response frame including information on the second transmission sector transmitted from the other wireless communication device in a later data transmission period;
The MAC processing circuit
Selecting a first transmission sector from information regarding the transmission sector of the wireless communication device included in the one or more beacon frames;
Generating one or more transmission sector sweep frames including information about the selected first transmission sector and information about a discovery request;
The transmission circuit includes:
Transmitting the one or more transmission sector sweep frames to the other wireless communication device during the beamforming training period;
In the data transmission period, using the information regarding the second transmission sector selected by the other radio communication device included in at least one of the feedback frame and the probe response frame, the other radio communication device Send data,
Wireless communication device.