JP5572248B2 - Wireless terminal and wireless communication method - Google Patents

Description

  Embodiments described herein relate generally to a radio terminal having two or more transceivers having different channels or modes and a radio communication method thereof, for example, a method of changing a transceiver that transmits and receives frames between radio terminals communicating with each other. .

  2. Description of the Related Art Conventionally, there are proposals for transmitting a frame from a plurality of channels that have a plurality of channel links between wireless terminals. For example, there is one that transmits different frames in parallel on two channels (see, for example, Patent Document 1).

JP 2004-350259 A

  However, in the above-described prior art, in order to receive frames in the order of sequence numbers across a plurality of channels on the receiving side, frame order setting (sequence number setting) in a transmission procedure is performed by a transmitter. Where (or in which processing stage) it is performed, a restriction is imposed on the transmitter configuration.

  The embodiment of the present invention has been made to solve the above problem, and accepts frames in order on the receiving side while allowing a flexible transmitter configuration when performing frame transmission across multiple channels. An object of the present invention is to provide a wireless terminal and a wireless communication method.

A wireless terminal as one aspect of the present invention is:
A wireless terminal that communicates with other wireless terminals,
A frame distribution unit for performing a distribution process of data frames to be transmitted to the other wireless terminals;
First sequence number assigning means for assigning a sequence number to an input data frame, and transmitting the data frame to which the sequence number is assigned to the other wireless terminal in a first channel or a first mode. 1 communication unit;
Second sequence number assigning means for assigning a sequence number to the input data frame, and sending the data frame assigned the sequence number by the second sequence number assigning means to the other radio terminal in the second channel Or a second communication unit that transmits in the second mode,
The frame distribution unit inputs a data frame to one of the first and second communication units,
When changing the data frame transmission to the other wireless terminal from the one communication unit to the other communication unit, the channel or mode corresponding to the one communication unit is changed to the channel or mode corresponding to the other communication unit. A change notification for changing and a transmission start sequence number that is a sequence number to start transmission by the other communication unit is transmitted from the first communication unit or the second communication unit to the other wireless terminal, The one communication unit inputs at least an untransmitted data frame addressed to the other wireless terminal held in the one communication unit to the other communication unit, and the frame distribution unit includes the other wireless terminal. The distribution destination of the data frame addressed is switched from the one communication unit to the other communication unit, and the sequence number assigning means of the other communication unit The sequence number starting from the transmission start sequence number assigned to the other data frames of the wireless terminal addressed input to the communication unit,
The first communication unit includes the sequence number assigned to the data frame transmitted from the first communication unit and a delivery confirmation from the other wireless terminal for the data frame transmitted from the first communication unit. Based on the status of the reception sequence number described in the frame, manage the delivery status of the data frame transmitted from the first communication unit and perform retransmission grasp,
The second communication unit includes the sequence number assigned to the data frame transmitted from the second communication unit and a delivery confirmation from the other wireless terminal for the data frame transmitted from the second communication unit. Based on the status of the reception sequence number described in the frame, the retransmission status is managed by managing the delivery status of the data frame transmitted from the second communication unit.

A wireless communication method as one aspect of the present invention includes:
A wireless communication method for performing wireless communication with another wireless terminal using a first communication unit that performs communication in the first channel or the first mode and a second communication unit that performs communication in the second channel or the second mode Because
A frame distribution step of inputting a data frame to be transmitted to the other wireless terminal to one of the first and second communication units;
A first transmission step of assigning a sequence number to the data frame input to the first communication unit and transmitting the data frame to the other wireless terminal in the first channel or the first mode;
A second transmission step of assigning a sequence number to the data frame input to the second communication unit and transmitting the data frame to the other radio terminal in the second channel or the second mode;
When changing the data frame transmission to the other wireless terminal from the one communication unit to the other communication unit, the channel or mode corresponding to the one communication unit is changed to the channel or mode corresponding to the other communication unit. A change notification to change and a transmission start sequence number that is a sequence number to start transmission by the other communication unit is transmitted from the first communication unit or the second communication unit to the other wireless terminal A notification step;
When changing the data frame transmission to the other wireless terminal from the one communication unit to the other communication unit, at least an untransmitted data frame addressed to the other wireless terminal held in the one communication unit A frame moving step to be input to the other communication unit;
A switching step of switching the data frame distribution destination from the one communication unit to the other communication unit when changing the data frame transmission to the other wireless terminal from the one communication unit to the other communication unit; ,
When changing the data frame transmission to the other wireless terminal from the one communication unit to the other communication unit, the transmission start sequence is added to the data frame addressed to the other wireless terminal input to the other communication unit. A communication unit change corresponding sequence giving step for assigning a sequence number starting from a number;
The sequence number assigned to the data frame transmitted from the first communication unit and the reception sequence number described in the delivery confirmation frame from the other wireless terminal for the data frame transmitted from the first communication unit Managing the delivery status of the data frame transmitted from the first communication unit based on the status of
The sequence number assigned to the data frame transmitted from the second communication unit, and the reception sequence number described in the delivery confirmation frame from the other wireless terminal for the data frame transmitted from the second communication unit Managing the delivery status of the data frame transmitted from the second communication unit based on the status of
It is provided with.

The figure which showed the example which the radio | wireless terminals as one Embodiment of this invention connect. The figure which showed another example in which the radio | wireless terminals as one Embodiment of this invention connect. The figure which shows the structural example of the radio | wireless terminal which concerns on one Embodiment of this invention. The figure which shows the structural example of the MAC frame of IEEE802.11. The figure which shows the structural example of BA (Block Ack) frame. The figure which shows the structural example of the radio | wireless terminal which concerns on 1st Embodiment. The figure explaining the operation example of 1st Embodiment. The figure explaining another example of operation of a 1st embodiment. FIG. 6 is a diagram for explaining still another operation example of the first embodiment. The figure explaining the operation example of 5th Embodiment. The figure which shows the structural example of the radio | wireless terminal which concerns on 7th Embodiment. The figure explaining the operation example of 7th Embodiment. The figure explaining the operation example of 9th Embodiment. The figure explaining the operation example of 10th Embodiment. The figure which shows the structural example of the radio | wireless terminal which concerns on 11th Embodiment. The figure explaining the operation example of 11th Embodiment. The figure which shows the structural example of the radio | wireless terminal which concerns on 12th Embodiment. The figure explaining the operation example of 12th Embodiment. The figure which shows the structural example of the radio | wireless terminal which concerns on 13th Embodiment. The figure explaining the operation example of 13th Embodiment. The figure explaining the operation example which concerns on 15th Embodiment.

  Hereinafter, the present embodiment will be described in detail with reference to the drawings.

  FIG. 1 shows an example in which wireless terminals according to an embodiment of the present invention are connected to each other. In FIG. 1, as two wireless terminals, a wireless terminal 201 (STA 201) and a wireless terminal 202 (STA 202) are connected to each other. The number of wireless terminals is not limited to two, and a plurality of wireless terminals may exist and each wireless terminal may be connected to a plurality of other wireless terminals.

  Further, as shown in FIG. 2, one of the two radio terminals may be a radio base station. In FIG. 2, the wireless base station 101 (AP101) is connected to the wireless terminal 201 (STA201). The wireless base station 101 may be connected to one or more wireless terminals other than the wireless terminal 201, or may be connected to one or more other wireless base stations, or connected to a wired network. It may be connected. The wireless terminal 201 may be connected to one or more wireless terminals other than the wireless base station 101. Hereinafter, the radio base station is also described as a radio terminal unless otherwise distinguished.

<Definition of Wireless Communication Group (BSS)>
When a single wireless communication group is formed as shown in FIGS. 1 and 2, this is particularly called BSS (Basic Service Set) in the IEEE802.11 wireless LAN.

<Connection definition>
The “connection” between wireless terminals refers to a state in which the existence of each other is recognized and the mutual capability (Capability) necessary for realizing some wireless communication is grasped. The mutual ability is grasped by, for example, notifying each other's ability between the wireless terminals. One means is through an authentication process. In the IEEE802.11 wireless LAN system, for example, this is an association process performed by exchanging management frames called association request and association response. The other means is a method of transmitting and grasping frames that notify each other of their abilities. In the IEEE 802.11 wireless LAN system, for example, when transmitting a management frame called Beacon, which is also a synchronization signal and also has a role of indicating the attribute of the communication group (BSS), this Beacon frame has a field for notifying its own ability The other wireless terminal that has received the Beacon frame can thereby grasp the capability of the wireless terminal. Further, as a management frame similar to this Beacon frame, there is a Probe Response frame that can be obtained as a response when a Probe Request frame is transmitted. The capability of the wireless terminal that is the transmission source can be grasped by this Probe Response frame. Wireless communication can be performed between wireless terminals in a connected state.

<Wireless terminal configuration>
FIG. 3 shows a configuration example of a wireless terminal according to an embodiment of the present invention. Each illustrated element forming the wireless terminal may be configured as hardware, may be configured as a software module, or may be configured by both of them.

  As shown in FIG. 3, the common MAC processing unit (frame distribution unit) 2 is connected to the first transmission / reception unit (first communication unit) 10 and the second transmission / reception unit (second communication unit) 20. Yes. The common MAC processing unit 2, for example, the first transmission / reception unit 10 or the second transmission / reception unit generates data generated through a logical link control (Logical Link Control; LLC) layer defined by the IEEE802 standard. The transmission status of the frame sent from the first transmission / reception unit 10 or the second transmission / reception unit 20 is transferred to the LLC. Conversely, the common MAC processing unit 2 performs control to pass the contents (payload) of the frame received via the first transmitting / receiving unit 10 or the second transmitting / receiving unit 20 to the LLC. When the wireless terminal is a wireless base station, the common MAC processing unit 2 may be connected to a wired network.

<First transceiver 10 and second transceiver 20>
The first transmission / reception unit 10 and the second transmission / reception unit 20 use different channels. The channel used by the first transceiver 10 corresponds to the first channel, and the channel used by the second transceiver 20 corresponds to the second channel. The channel is mainly a channel divided on the frequency, but may be a channel by code division or the like. As described above, the wireless terminal according to the present embodiment is a wireless terminal corresponding to a plurality of channels, that is, a multi-channel wireless terminal.

  The first transmission / reception unit 10 and the second transmission / reception unit may be distinguished by a frequency band level obtained by bundling a plurality of frequency channels. For example, the first transmission / reception unit 10 may use any of the channels for 5 GHz band IEEE802.11a, and the second transmission / reception unit 20 may use any of the channels for 2.4 GHz band IEEE802.11b / g. Each channel in the 5 GHz band and the 2.4 GHz band does not need to be fixed, and the channel may be changed within the frequency band. In this case, since it can be said that the transmission / reception method is different in IEEE802.11a, IEEE802.11b, and IEEE802.11g, the wireless terminal of the present embodiment is not only a different channel but also a multimode wireless terminal having a different transmission / reception method. Can be called. Furthermore, the first transmission / reception unit 10 and the second transmission / reception unit 20 may largely differ in transmission / reception method. For example, the first transmission / reception unit 10 is based on the 60 GHz band IEEE 802.15.3c wireless PAN standard, and the second transmission / reception unit 20 is based on the 5 GHz band IEEE 802.11a wireless LAN standard. As is.

  The first transmission / reception unit 10 includes a first MAC (Media Access Control) processing unit 11, a first PHY processing unit 15, and a first antenna 18.

  The second transmission / reception unit 20 includes a second MAC processing unit 21, a second PHY processing unit 25, and a second antenna 28.

  The first MAC processing unit 11 and the second MAC processing unit 21 are connected to the common MAC processing unit 2, and MAC frame generation, access control during transmission, reception frame processing (including response frame transmission, etc.), Performs management and other processing related to settings between wireless terminals. These include, for example, IEEE802.11 wireless LAN (including a series of extended and complementary standards such as 802.11a, b, e, g, h, i, j, n, etc.) and IEEE802.15 wireless PAN (802.15. There are operations defined as the MAC layer (including a series of extended and complementary standards such as 3 and 802.15.3c). The MAC processing units 11 and 21 may have a work area and a frame buffer, and may have a memory for wireless terminal information. These may be externally attached to the MAC processing units 11 and 21 instead of within the MAC processing units 11 and 21, and may be used for other processing than the MAC layer.

  For example, management information that is shared by the first transmitter / receiver 10 and the second transmitter / receiver 20 such as information on wireless terminals to be connected by both the transmitter / receivers 10 and 20 is held by the common MAC processing unit 2. May be. The wireless terminal to be connected is a multi-channel wireless terminal or a multi-mode wireless terminal having the capability of communicating with both the first and second transceivers. In this case, for example, in the first / second MAC processing unit 11/21, the role is divided so as to hold the setting information of the wireless terminal necessary for connection by the first / second transmission / reception unit 10/20. It may be. The common MAC processing unit 2 uses the first transmitter / receiver 10 to transmit the information based on terminal information managed internally and information acquired from the first / second MAC processing unit 11/21 if necessary. You may make it judge, such as distribution whether it transmits using the transmitter / receiver 20. FIG.

  In FIG. 3, the first MAC processing unit 11 and the second MAC processing unit 21 are connected, but they may be connected via the common MAC processing unit 2 instead of being directly connected.

  The first PHY processing unit 15 and the second PHY processing unit 25 are respectively connected to the first MAC processing unit 11 and the second MAC processing unit 21, and generate PHY packets from the MAC frame, and perform modulation encoding. Processing, grasping the state of the wireless medium (air), demodulating and decoding the received signal, notifying the MAC processing unit of the received packet and reception state information, and the like. These are prescribed operations of the PHY layer in, for example, an IEEE802.11 wireless LAN system or an IEEE802.15 wireless PAN system. In addition, the PHY processing units 15 and 25 perform digital / analog conversion of the signal in order to radiate transmission packets as radio waves from the first antenna 18 and the second antenna 28, respectively, and gradually convert the frequency of the transmission signal Perform the process. In addition, when the received radio wave is input from the first / second antennas 18/28, the PHY processing units 15 and 25 perform step-by-step conversion of the frequency of the received signal and perform analog / digital conversion.

  For example, data input from the LLC layer is distributed to the first transmission / reception unit 10 or the second transmission / reception unit 20 by the common MAC processing unit 2, and the MAC processing unit (the first MAC processing unit 11 or the first MAC processing unit in each transmission / reception unit). 2 MAC processing unit 21) is converted to a MAC frame, PHY processing unit (first PHY processing unit 15 or second PHY processing unit 25) is converted to a PHY packet, further converted to an analog signal, antenna ( It is transmitted as a radio signal from the first antenna 18 or the second antenna 28). Conversely, the radio signal received from the antenna (the first antenna 18 or the second antenna 28) is the PHY processing unit (the first PHY processing unit 15 or the second PHY processing unit 25), the MAC processing unit (first The data is processed via the MAC processing unit 11 or the second MAC processing unit 21) and the common MAC processing unit 2, and the data addressed to the terminal is output to an upper layer such as the LLC layer.

  As described above, the wireless terminal according to the present embodiment is a multi-channel wireless terminal or a multi-mode wireless terminal having the first transmitting / receiving unit and the second transmitting / receiving unit.

  Note that the system as shown in FIG. 1 or 2 may be composed of only the multi-channel / multi-mode wireless terminals of the present application, or non-multi-channel / non-multi-mode wireless terminals may be mixed. In the case where non-multichannel / non-multimode wireless terminals coexist, the present invention is directed to the case where frames are transmitted and received using a plurality of channels between multichannel / multimode wireless terminals.

<Handling of frames in the MAC processor in 802.11>
<MAC frame>
In the IEEE802.11 wireless LAN, the MAC frame is roughly divided into three types, a data frame, a management frame, and a control frame. These types are indicated in a type field in the frame control field of the MAC header part. Further, a subtype field is provided in the frame control field in order to distinguish individual frame types.

  A data frame is basically a frame generated from data passed from the upper layer of the MAC layer (for example, the LLC layer). In some cases, for example, empty data is generated in the MAC layer, and a frame generated in the future is used as a data frame.

  The management frame is a frame for transmitting management information at the MAC layer level. For example, there are the aforementioned Beacon frame, Probe Request frame, Probe Response frame, Association Request frame, Association Response frame, and the like.

  The control frame is a frame used for access control in the MAC layer. For example, RTS frame for channel reservation before sending data frame or management frame and CTS frame that is the response frame (CTS frame can also be transmitted alone for direct channel reservation), delivery confirmation Ack (Acknowledgment) frame that responds sequentially to data frames and management frames as a frame, BA (Block Acknowledgment) frame that returns responses to multiple data frames at once, BAR (Block Acknowledgment Request) for requesting BA frames There are frames.

  The MAC frame in IEEE802.11 is passed to the PHY layer as an MPDU having a frame configuration as shown in FIG. FIG. 4 shows a general frame structure, and some fields may not exist depending on the frame. A data frame before such a frame configuration is called an MSDU (MAC Service Data Unit), and a management frame before such a frame configuration is called an MMPDU (MAC Management Protocol Data Unit).

<Sequence number>
MSDU and MMPDU are given a sequence number which is the order of frames. Specifically, the order is described in the sequence number field (Sequence Number field) in the sequence control field (Sequence Control field) of the MAC header when it becomes an MPDU. Specifically, in the case of a QoS data frame having a traffic type (Traffic IDentifier; TID), a counter is provided for each direct destination address for each TID, and the sequence number of the frame is incremented by one. However, regarding what is called a QoS Null frame (may be a QoS (+) Null frame including the addition of an ACK response) that transmits empty data generated inside the MAC layer, it is a sequence. Numbers can be given any value. This is because processing is closed inside the MAC layer. A counter different from MSDU is prepared for the MMPDU, and a sequence number is given.

  Further, when MSDU and MMPDU become MPDU, they may be divided into fragments having a short frame length as necessary (fragment processing). In this case, the fragment number is also assigned to the fragment number field (Fragment Number field) in the sequence control field of the MAC header part in order to reconstruct the unit MSDU and MMPDU (defragment processing) on the receiving side.

<Reception processing>
In 802.11 wireless LAN or the like, a Frame Check Sequence (FCS) is inserted at the end of the frame in order to determine whether the frame is received in a normal state with no errors. For example, in the general MAC frame format in IEEE802.11 wireless LAN (see Fig. 4), the FCS at the end is formed from the Cyclic Redundancy Code (CRC), and the CRC is a Frame that contains the MAC header, data from LLC, etc. It is a value calculated from the Body field. The reception side checks the CRC, and if an error is detected, subsequent reception processing such as extraction of the address of the transmission destination wireless terminal is not performed. In this case, access to the channel is basically performed after a fixed time of EIFS (Extended InterFrame Space) waiting for the expected maximum time assuming transmission of an acknowledgment response (an ACK frame described later). If no error is detected as a result of the CRC check, the reception process is continued. For example, if the direct destination address is not addressed to the terminal itself, NAV (Network Allocation) is used to activate virtual carrier sense for a certain period of time based on the Duration / ID field and Subtype field described in the MAC header. Set Vector).

  On the receiving side, in the case of data frames and management frames, if it recognizes that the direct destination (Receiver Address; RA) is addressed to itself by the address field (details will be described later) of the MAC header part of the MPDU, An Acknowledgment (ACK) frame that is a delivery confirmation response to be transmitted for each MPDU after a fixed time called SIFS (Short InterFrame Space) is transmitted. For such a received frame, the address of the direct destination is extracted from the address field and transmitted from the same wireless terminal, and the value of the sequence number field (Sequence Number field) in the MAC header is the same. Yes, MPDUs are rearranged in order of fragment numbers for MPDUs having different fragment number fields (fragment number fields), and reconstructed in units of MSDU for data frames and MMPDU for management frames (defragment processing). Subsequent reception processing is performed in the order of the sequence numbers. For example, if the final destination (Destination Address; DA) of the data frame is the own terminal, the reception processing is a service primitive (service primitive) called MA-UNITDATA.indication from the MAC layer to the frame body field after the defragment processing as a payload. ). In the management frame, the direct transmission destination and the final destination address are the same (RA = DA), and if the final destination address is the own terminal, the contents of the management frame are processed in the order of the sequence number.

<Description of address field>
In the IEEE802.11 wireless LAN, the address of the direct destination wireless terminal is written in the first address field (Address 1 field in FIG. 4) of the MAC header. Although the final destination address varies depending on the situation, it is Address 1 or enters Address3 if the final destination and the direct destination address are different. When the final destination address and the direct transmission destination address are the same (DA = RA), the final destination address may be described in the Address 1 field. The address of the direct transmission source wireless terminal of the frame is written in the second address field (Address 2 field in FIG. 4) of the MAC header in the IEEE802.11 wireless LAN.

<Same communication group (BSSID)>
Also, in the IEEE802.11 wireless LAN, for frames exchanged within the same wireless communication group (BSS), the wireless communication group identifier (BSS Identifier; BSSID) is set in the address field (Address 1, Address 2, and Address 3 in FIG. 4). In any field). The address field in which the identifier of the wireless communication group is entered differs depending on the role of each wireless terminal that transmits and receives within the wireless communication group.

<Definition of radio base station>
Here, the wireless base station may be a wireless terminal that can transfer data from other terminals (including terminals connected by wire in addition to wireless terminals. In addition, wireless base stations are included). For example, in the IEEE802.11 wireless LAN, a plurality of wireless communication groups can be combined to construct one wireless communication system (Extended Service Set; ESS). And between wireless communication groups in this wireless communication system is called Distributed System (DS). The DS may be wired or wireless, but the wireless base station can also be defined as a wireless terminal that can be connected to the DS.

<Example of field that contains communication group identifier>
In the IEEE802.11 wireless LAN, since the address of the wireless base station is the identifier of the wireless communication group, for example, the transmitting wireless terminal is the wireless base station, and the wireless terminal receiving the data frame is the non-wireless base station If it is a wireless base station terminal), the identifier of the wireless communication group is set in the Address 2 field, and when the non-wireless base station terminal transmits a data frame to the base station terminal, the identifier of the wireless communication group is It is designed to be entered in the Address 1 field. When transmitting and receiving data frames between non-radio base station terminals (even in the case of a BSS without a radio base station as shown in FIG. 1, there is a radio terminal 202 in addition to the radio terminal 201 in the configuration of FIG. The wireless communication group identifier is set in Address 3 (when the wireless terminal 202 communicates). When transmitting a management frame, the identifier of the wireless communication group is set in Address 3. For example, in the IEEE802.11 wireless LAN as shown in FIG. 1, the identifier of the communication group is determined by a random number by the wireless terminal that started the communication group. When transmitting and receiving data frames between wireless terminals that are wireless base stations, it is a DS-level frame that connects the previous wireless communication group and the wireless communication group, so there is no need to specify the identifier of the wireless communication group (transmission This is because the destination address is the same as the identifier of one wireless communication group, and the direct source address of the frame is the same as the identifier of the other wireless communication group).

<Example of filtering by communication group identifier>
When a received frame is received from the PHY layer, it is checked whether a normal frame is received by CRC check or the like. After that, it is determined by looking at a predetermined address field whether the identifier of the wireless communication group is the same as the identifier of the wireless communication group to which the own wireless terminal belongs according to the frame type for the frame determined to be normal. May include actions.

<Block Ack Mechanism>
In IEEE802.11 wireless LAN, there is a mechanism in which delivery confirmation responses to a plurality of data frames are collectively transmitted, and a non-reachable data frame is retransmitted in a transmitting wireless terminal that has received the delivery confirmation response. This is called the Block Ack (BA) mechanism. The BA mechanism can be applied to QoS data frames in which TID (traffic type) is distinguished. In the service primitive MA-UNITDATA.request used when the MAC layer receives data from the upper layer, a priority parameter is entered as a variable together with the data, and the value is handled in the MAC layer as a TID. The TID is expressed as an integer from 0 to 15, and the priority order of access rights is assigned based on this TID. (For QoS data frames generated inside the MAC layer, TIDs are assigned as appropriate according to the purpose of use. ).

  When the BA mechanism is introduced, the receiving wireless terminal does not necessarily receive the data frames in the order of the sequence number. Therefore, in order to pass the data from the MAC layer to the upper side in the same order as the receiving side received from the upper side, A mechanism for rearranging them in order is required. The part that performs this reordering process is called a receive reordering buffer control part, particularly for a scoreboard context control part in IEEE802.11n described later. The receive reordering buffer control unit is abbreviated as a reordering buffer (reordering buffer). A reordering buffer is provided for each different TID. This is because sequence numbers are assigned differently in frames with different TIDs.

  In addition, in order to transmit a delivery confirmation response to a plurality of data frames, it is necessary to hold a reception status for each data frame. In the IEEE802.11n wireless LAN, the reception status part for delivery confirmation response for holding the reception status is called the above-mentioned scoreboard context control part. The scoreboard context control part is abbreviated as scoreboard. The scoreboard is also referred to as a reception status storage unit. The scoreboard is also provided for each different TID because the sequence numbers are assigned differently in frames with different TIDs.

  The reception status is notified to the wireless terminal on the data transmission side by a BA (Block Ack) frame as shown in FIG. As a method for the transmitting wireless terminal to request the BA wireless frame from the receiving wireless terminal, there are a method of transmitting and requesting a Block Ack Request (BAR) frame that is a control frame, and a method of placing a request in the data to be transmitted. is there.

  The former is called an explicit block ack request, and the address information of the requesting wireless terminal and the requesting wireless terminal, information on which TID frame is requested, and where the delivery confirmation response of the sequence number is requested ( The information of Starting Sequence Number (SSN) is indicated in the BAR frame and a delivery confirmation response is requested.

  The latter is called an implicit block ack request, and requests a delivery confirmation response from the receiving wireless terminal by a combination of a field for designating the type of the delivery confirmation response of the data to be transmitted and the form of the transmitted frame. Specifically, in the case of a transmission form using an aggregation method in which a plurality of MPDUs are combined into a PHY packet as one MPDU (a form in which the plurality of MPDUs are combined is called an aggregate MPDU (A-MPDU)) By indicating the Normal Ack policy that sequentially requests responses in the field for specifying the type of confirmation response, the receiving wireless terminal stores the reception status information held for the TID of the data indicating the Normal Ack policy in BA. Notify the sending wireless terminal in a frame. The TID of each data frame is indicated by a QoS control field in FIG.

  In both the former and the latter cases, an SSN (Starting Sequence Number) indicating where the reception status of the sequence number is notified is placed in the BA frame as shown in FIG. Specifically, the reception status is assigned to each MSDU in the order of the sequence number from the relevant SSN (compressed), or to each MPDU in the order of the fragmentation number in the corresponding sequence number location (basic). Indicated by Block Ack Bitmap.

  The wireless terminal that receives the data frame sets 1 in the corresponding block Ack Bitmap for the received frame, and the frame that has not been received or has no reception status (for example, the location of an unused fragment number or the retention If the area other than the scoreboard is returned in the bitmap, this is the case.) Set the corresponding block Ack Bitmap to 0. In the following examples, Block Ack Bitmap will be explained mainly using the former case of notifying the delivery confirmation response in MSDU units (compressed) (in this case, the data transmission side will not perform fragmentation), The basic operation does not change even when the fragmentation number information is (basic).

<Variation related to selective retransmission in multi-channel / multi-mode>
When using the selective retransmission method between multi-channel / multi-mode wireless terminals,
・ Whether the sequence number is unified between channels / modes or can be assigned separately.
・ Whether the reordering buffer is provided in common for both channels / modes or separately,
・ Whether to use the same wireless terminal address for both channels / modes
-Whether the traffic type (TID) is common or changeable in both channels / modes.

  Hereinafter, each embodiment of the present invention will be described based on these variations.

(First embodiment)
In the first embodiment, a case will be described in which sequence numbers are assigned separately between channels / modes, and a reordering buffer is provided in common for both channels / modes. Each wireless terminal address is common between channels / modes, and TID assignment is also common between channels / modes.

  The configuration of the wireless terminal according to the first embodiment is as shown in FIG. 6 based on FIG.

  The reordering buffer 30 is in the common MAC processing unit 2, and the sequence number assigning units (SN assigning units) 12 and 22 are in the first MAC processing unit 11 and the second MAC processing unit 21, respectively, and the sequence number assigning unit A transmission frame is put into the transmission queues 13 and 23 via 12 and 22. Further, scoreboards 14 and 24 holding reception status when operating as a receiving side are also provided in the first MAC processing unit 11 and the second MAC processing unit 21, respectively.

  When reordering buffer 30, sequence number assignment units 12, 22, transmission queues 13, 23, scoreboards 14, 24 do not show how they relate to other processing operation units, but MSDU is transmitted Is as follows. That is, the MSDU is distributed from the common MAC processing unit 2 to the first MAC processing unit 11 or the second MAC processing unit 21 to form an MPDU, and then the transmission queue 13 or SN via the SN allocation unit 12 or the SN allocation unit 22 It is placed in the transmission queue 23. When a desired channel access is made by the first MAC processing unit 11 or the second MAC processing unit 21 and a transmission right is acquired, the MPDU in the transmission queue 13 or the transmission queue 23 is changed to the first PHY processing unit 15 or the second PHY processing unit 15 To the PHY processing unit 25 and transmitted from the first antenna 18 or the second antenna 28.

  At the time of frame reception, the first MAC processing unit or the second MAC processing unit from the first antenna 18 or the second antenna 28 via the first PHY processing unit 15 or the second PHY processing unit 25 The frame is input as an MPDU. Corresponds to the sequence number of the frame received normally (or the fragment number in the part corresponding to the corresponding sequence number in some cases) if the frame is a data frame and requires a delivery confirmation response using the Block Ack mechanism Record that it is received in the corresponding part of the scoreboard 14 or scoreboard 24 (specifically, the scoreboard usually has the same bitmap structure as the Block Ack bitmap, and the corresponding sequence number (or Depending on the sequence number, the corresponding bit portion of the portion corresponding to the sequence number is set to 1. Hereinafter, this configuration will be described as a premise).

  An operation example of transmission / reception processing between the transmission-side wireless terminal and the reception-side wireless terminal will be described with reference to FIG. At this time, it is assumed that necessary settings for using the Block Ack mechanism for frame exchange have already been completed between the transmitting-side wireless terminal and the receiving-side wireless terminal. This setting is performed by exchanging an ADDBA Request frame and an ADDBA Response frame in the IEEE802.11 wireless LAN.

  In FIG. 7, the transmission side wireless terminal first has a sequence number corresponding to the channel to which the first transmitter / receiver 10 corresponds (this will be referred to as the first channel here. Of course, the mode may be the first mode in this case). Each frame from 1 to 5 is transmitted by A-MPDU. In this example, the A-MPDU includes an implicit block ack request.

  When the receiving wireless terminal receives the A-MPDU with the first transceiver 10, the receiving side wireless terminal records the sequence number of the normally received frame on the scoreboard (first scoreboard) 14 in the first MAC processing unit 11. . In the example of Fig. 7, the frame with sequence number 1 in the A-MPDU was received normally, but the other frames were not received normally and the sequence number could not be grasped, so the bit corresponding to sequence number 1 on the scoreboard 14 Just set 1 to the part and leave the others as 0.

  The received frame is sent to a reordering buffer 30 that is common between channels / modes. If the starting sequence number (SSN) is set to 1 when setting the Block Ack mechanism, the reordering buffer 30 sets the minimum sequence number in the frame waiting state to 1. For this reason, when a frame with a sequence number of 1 enters the reordering buffer 30, this sequence number 1 matches the minimum sequence number in the standby state, so this frame is transferred from the MAC layer to the upper layer (LLC layer). To pass. Then, the minimum sequence number in the frame waiting state is set from 1 to the next 2 (incremented by 1).

  When a frame with a different sequence number is received without receiving a frame with the lowest standby sequence number, the following occurs. That is, frames are accumulated in the reordering buffer 30 in the order of sequence numbers. When the reordering buffer 30 is full, the standby with the smallest sequence number is discarded, and the minimum sequence number for standby is incremented by one. If the frames after the incremented sequence number are arranged in order, the frame is transferred from the MAC layer to the upper layer by the same processing as described above. At that time, the minimum sequence number for standby is also updated.

  When the first MAC processing unit 11 recognizes that the reception of the A-MPDU has been completed by a signal from the first PHY processing unit 15 (a primitive called PHY-RXEND.indication in the IEEE802.11 wireless LAN), A- Generates a Block Ack (BA) frame from the implicit block ack request shown in the MPDU, reflects the contents of the scoreboard 14 in the Block Ack Bitmap in the BA frame, and receives a fixed time (IEEE802.11 after receiving the A-MPDU). In wireless LAN, BA frame is transmitted after SIFS (fixed time). In FIG. 7, it is notified that the frame of sequence number 1 has been normally received by the BA frame.

  From the content of the received BA frame, for example, the transmitting wireless terminal determines that frame dropping is severe in communication using the first channel / mode, and the subsequent data transmission is performed by the second transceiver 20 corresponding to the channel / Suppose that it is decided to use a mode (here, this is called a second channel / mode). For example, the first transmitter / receiver 10 of the transmission side wireless terminal manages the delivery status of the transmission frame from the delivery confirmation response frame from the reception side wireless terminal, and the communication quality does not satisfy a certain standard in the first channel / mode. It is assumed that the second transmitter / receiver 20 has decided to change the transmission source. The same function can be determined by changing the second transceiver 20 to the first transceiver 10 by providing the second transceiver 20.

  The transmitting side wireless terminal determined in this way moves the frames of sequence numbers 2 to 5 from the first MAC processing unit 11 to the second MAC processing unit 21. More precisely, the frames of sequence numbers 2 to 5 that were in the transmission queue 13 in the first MAC processing unit 11 are passed through the sequence number assigning unit 22 of the second MAC processing unit 21 and new frames are added to these frames. A process of assigning a channel / mode sequence number to each and putting them in the transmission queue 23 is performed. At this time, the frame newly assigned by the second MAC processing unit 21 to the frame having the smallest sequence number among the frames transferred from the first MAC processing unit 11, that is, the frame having the sequence number 2 in FIG. The number is held in the second MAC processing unit 21. In the example of FIG. 7, the sequence number is 1.

  Next, the transmitting wireless terminal notifies the receiving wireless terminal that the channel / mode is changed. In this example, notification is performed using a management frame (represented as “Mg” in FIG. 7) different from a data frame in which a series of data exchange is performed. This is not for the purpose of transmitting data but for managing the operation of the wireless terminal. Furthermore, in IEEE802.11 wireless LAN, when a data frame is passed from the upper layer (LLC layer) of the MAC layer, a TID (traffic type) is uniquely assigned, and the priority at the time of transmission is determined from the TID. This is because the highest priority is given. This makes it easy to transmit the notification frame to the receiving wireless terminal before transmitting the data frame with the channel / mode changed.

  The channel / mode for transmitting the notification frame is here the second channel / mode to be switched to. This is because frame dropping is severe in the first channel / mode, so that there is a higher possibility that a management frame can be delivered properly if transmission is performed in the second channel / mode, which is expected to have high reliability.

  In the notification frame, data is transmitted in the second channel / mode (expressed as `` Tx in the second '' in FIG. 7), and the sequence number (SSN) for starting transmission in the change destination channel / mode is 1 (Expressed as “SN = 1 to Tx” in FIG. 7) as information. Here, the sequence number (SSN) for starting transmission in the change destination channel / mode is the frame transferred from the first MAC processing unit 11 that has been held, and the frame with the minimum sequence number is the second MAC processing unit 21. It is the newly assigned sequence number (here 1). Although omitted in FIG. 7, if the TID of the data frame subject to channel / mode change is not clear at the receiving wireless terminal only by the notification information, the corresponding TID information is put in the notification frame. Shall. If there is only one TID for which the Block Ack mechanism is set between wireless terminals, the target TID becomes clear at the receiving wireless terminal and can be omitted. In addition, this is not the case when the frame type (Subtype) of the management frame itself to be notified is changed corresponding to the TID of the target data frame.

  Normally, in an IEEE802.11 wireless LAN, a received wireless terminal transmits an Ack frame after SIFS time in a frame (unicast frame) transmitted to a single wireless terminal. Since it is not used, it is expressed as “Ack” in FIG.

  In the receiving wireless terminal that has received the notification frame to change the channel / mode, a process for raising all the received frames in the reordering buffer 30 in the common MAC processing unit 2 from the MAC layer to the upper layer (LLC layer) Then, the minimum sequence number in the frame waiting state is set to the transmission start sequence number notified in the frame.

  At this time, the receiving wireless terminal specifies the transceiver (in this case, the first transceiver 10) corresponding to the channel / mode in which the corresponding TID frame was exchanged with the transmitting wireless terminal. It is desirable to reset the scoreboard 14 in the MAC processing unit (in this case, the first MAC processing unit 11) of the corresponding transceiver. This is because, by resetting the scoreboard 14, the scoreboard 14 can be utilized for receiving another wireless terminal or another TID frame.

  Such resetting of the scoreboard is also effective when a method called partial state BA in IEEE802.11n is applied. In other words, when partial state BA in IEEE802.11n is applied, if there is no free scoreboard when receiving a frame from a new wireless terminal, even if the scoreboard is not reset, The scoreboard holding the status can be reset and used. However, by resetting the scoreboard 14 which is known to be no longer used as described here, the algorithm for selecting which one to reset if there are multiple scoreboards in the partial state BA is already It can be simplified such that an unused scoreboard is preferentially selected.

  There are the following methods for specifying the transceiver corresponding to the channel / mode in which the corresponding TID frame was exchanged with the transmitting wireless terminal. First, there is a method in which the TID is identified from the notification frame, and the transceiver that has processed the TID until the notification frame is received is determined in the common MAC processing unit 2 or the like. Second, when the notification frame includes information on which channel / mode to switch to (in this example, the second channel / mode), and the wireless terminal has only two channels / modes The channel / mode not exclusively indicated as the switching destination is determined to be the channel / mode in which the corresponding TID frame is exchanged with the transmitting wireless terminal, and the determined channel / mode There is a method for identifying a transceiver corresponding to a mode.

  When the transmitting wireless terminal transmits the notification frame and receives a response frame to the notification frame, the transmitting wireless terminal transmits a frame from the second transceiver 20 corresponding to the second channel / mode. These frames are obtained by retransmitting the sequence numbers of the frames having the sequence numbers 2 to 5 transmitted in the first channel / mode to the sequence numbers 1 to 4 by the second MAC processing unit 21. In FIG. 7, the response frame for the notification frame is an Ack frame, but the receiving wireless terminal separates the Ack frame from the response frame for the notification frame (the notification frame is managed when the processing of the reordering buffer 30 is completed). Similarly, if it is a frame, a management frame) may be transmitted, and the transmitting wireless terminal may transmit the frame in the channel / mode to be changed after receiving the response frame.

  When the receiving wireless terminal receives the frame in the second channel / mode, it records the reception status on the scoreboard 24 of the second MAC processing unit 21 and raises the received frame to the reordering buffer 30 of the common MAC processing unit 2 . In FIG. 7, all new frames with sequence numbers 1 to 4 transmitted in the second channel / mode are received normally, and the score board 24 records that frames with sequence numbers 1 to 4 are normal, and Frames with sequence numbers 1 to 4 are sequentially passed from the ordering buffer 30 to the upper layer of the MAC layer. As a result, considering the sequence numbers on the first channel / mode side, the sequence numbers 1, 2, 3, 4, and 5 are received in order.

  FIG. 7 shows an example in which the frames with the sequence numbers 2 to 5 in the first MAC processing unit 11 are moved to the second MAC processing unit 21 and transmitted, but the subsequent frames with the same TID are higher in the MAC layer. Is passed from the common MAC processing unit 2 to the second MAC processing unit 21, and a continuous sequence number (from sequence number 5 in this example) is assigned.

  FIG. 7 shows an example in which there is a frame to be transferred from the first MAC processing unit 11 to the second MAC processing unit 21, but a frame of a certain TID is originally transmitted from the first MAC processing unit 11. There is no frame to be transferred from the first MAC processing unit 11 to the second MAC processing unit 21, but the transmission of the same TID frame is switched to the transmission from the second MAC processing unit 21 from the next Operates as follows. That is, when the data frame passed from the upper layer of the MAC layer is distributed by the common MAC processing unit 2, the data frame of the TID is passed to the second MAC processing unit 21. Then, before transmitting the data frame of the TID in the second channel / mode, the minimum sequence number assigned by the sequence number assigning unit 22 of the second MAC processing unit 20 is notified by the notification frame. Other operations are the same as described above.

  Although FIG. 7 shows a case where the latter half of the transmission is not continuously received by the receiving wireless terminal, there are other cases where the receiving situation is not. Therefore, consider the case shown in FIG.

  Here, a situation is shown in which the transmitting wireless terminal is transmitting frames of sequence numbers 11 to 15. The receiving wireless terminal normally receives sequence numbers 11 and 13, and the reception status is recorded in the first scoreboard 14. In other words, 1 is set at the position corresponding to the sequence number 11 that has been normally received, 12 is set between the sequence numbers 11 and 13 and 0 is set as unreceived, and the sequence number 13 that has been normally received is set at 1 at the corresponding position. ing. After receiving the A-MPDU, a BA frame notifying that the frames having the sequence numbers 11 and 13 have been received is transmitted by an implicit block ack request. The received frames having sequence numbers 11 and 13 are raised to the reordering buffer 30 in the common MAC processing unit 2. When the minimum sequence number in the frame waiting state of the reordering buffer 30 is 11, the frame with the sequence number 11 is passed from the MAC layer to the upper layer. Since the frame with sequence number 12 has not been received, the reordering buffer 30 changes the minimum sequence number in the frame waiting state to 12, and retains the frame with sequence number 13.

  When the transmitting wireless terminal stops transmitting in the first channel / mode and decides to transmit in the second channel / mode, the transmitting wireless terminal notifies the switching as in the example in FIG. Send the frame to the receiving wireless terminal.

  The receiving wireless terminal that has received the notification frame performs the same processing as described above. Particularly in this example, since the frame of sequence number 13 is held in the reordering buffer 30 while waiting for reception of the frame of sequence number 12, the frame of sequence number 13 is transferred from the MAC layer to the upper layer.

  The transmitting side wireless terminal knows that the sequence numbers 12, 14, and 15 transmitted in the first channel / mode are not received by the receiving side wireless terminal. Frames to be retransmitted after switching to the second channel / mode are frames with sequence numbers 14 and 15, and there is a gap between sequence numbers 11 and 13 that are normally received in the reception status indicated by the BA frame 12 Is not retransmitted in the second channel / mode. Frames transmitted as sequence numbers 14 and 15 in the first channel / mode are assigned sequence numbers 1 and 2 in the second channel / mode and transmitted.

  The receiving-side wireless terminal normally receives the frames assigned with these new sequence numbers 1 and 2, and raises them to the upper level via the reordering buffer 30. Considering the sequence numbers in the first channel / mode, sequence numbers 11, 13, 14, and 15 are received.

  In the example of FIG. 8, the reception status from sequence number 11 is returned in the BA frame. For example, if only the reception status from sequence number 13 is returned, both the sequence numbers 11 and 12 are not received by the receiving wireless terminal. In this case, the frame of the missing portion is that of sequence numbers 11 and 12.

  The frame of the missing part is not received by the receiving wireless terminal after the above-mentioned channel / mode changing process. To prevent this, the missing part is retransmitted before the channel / mode changing process is performed. The same channel / mode (here, the first channel / mode) may be used.

  Next, the case of further different reception situations will be described with reference to FIG. FIG. 9 shows a case where the transmitting wireless terminal cannot clearly determine whether the receiving wireless terminal has received a frame.

  The transmitting wireless terminal transmits frames with sequence numbers 11 and 12 in A-MPDU in the first channel / mode, and the receiving wireless terminal normally receives the frame with sequence number 11 as a BA frame. A response is returned. The receiving radio terminal performs processing for raising the frame number 11 data from the reordering buffer 30 to the upper layer of the MAC layer. In this situation, the transmitting side wireless terminal knows that the frame of sequence number 12 has not been received by the receiving side wireless terminal, and there is no discrepancy in the situation recognition with the receiving side wireless terminal.

  Next, it is assumed that the transmission side wireless terminal retransmits the frame of sequence number 12 in the form of requesting an Ack frame of immediate response in the first channel / mode (in this case, a retry bit to be described later is set to 1). The receiving wireless terminal receives the frame with the sequence number 12 and transmits an Ack frame, and raises the frame with the sequence number 12 to the reordering buffer 30. In the reordering buffer 30, the sequence number 12 is next to the sequence number 12. Since the frames are coming in order, the frame with the sequence number 12 is sent to the process for raising it to the upper layer of the MAC layer.

  Here, it is assumed that the Ack frame from the reception-side wireless terminal cannot be normally received, such as when the transmission-side wireless terminal receives an error. Then, the transmitting wireless terminal cannot obtain confirmation that the receiving wireless terminal has received the frame of sequence number 12. In this situation, there is a difference in recognition of the situation between the transmitting wireless terminal and the receiving wireless terminal. If the transmitting side radio terminal changes the channel / mode at this stage, it is not possible to transmit the frame of sequence number 12 that has been received by the receiving side radio terminal and has no confirmation in the channel / mode to be changed. This is because the receiving-side wireless terminal cannot recognize that the frame with the different sequence number transmitted in the channel / mode to be changed is the same as the frame with the sequence number 12 received before, that is, duplicate reception of data. It is. Therefore, as shown in FIG. 9, frames with sequence numbers after 13 that have not yet been transmitted in the first channel / mode are reassigned to the sequence numbers starting from 1 in the second channel / mode and transmitted. If these frames are normally received by the receiving wireless terminal, considering the sequence numbers in the first channel / mode, the receiving wireless terminal will eventually end up with sequence numbers 11, 12, 13, 14, 15 Will be received.

  Here, the receiving wireless terminal transmits an Ack frame for the frame of sequence number 12 received in the first channel / mode, but the frame of sequence number 12 is a TID frame for which the Block Ack mechanism is set. Therefore, the reception status is recorded on the score board 14 as shown in FIG. Therefore, if the transmitting side wireless terminal requests that the reception status for the frame from sequence number 11 or 12 is transmitted in the BA frame, it can be notified that the frame of sequence number 12 has been received by the BA frame. it can. Therefore, for sequence number 12 for which there is no confirmation of reception before the channel / mode change, a request is made to retransmit in the same channel / mode as described above, or to return the reception status including sequence number 12 in a BA frame. The reception status of sequence number 12 can be reconfirmed by a method such as

  In the example of FIG. 9, the frame having the sequence number 12 is transmitted in the form of requesting the Ack frame, but one frame having the sequence number 12 is set as an A-MPDU (in this case, the PHY packet has a plurality of MPDUs). However, if you include an implicit block ack request, the Ack frame is changed to a BA frame. Similarly to the Ack frame, the BA frame cannot be confirmed in the same manner unless the frame itself is lost and the frame itself can be grasped.

<Sender restrictions>
As can be understood from the examples shown in FIG. 8 and FIG. 9, the frames that can be retransmitted at the channel / mode change destination by the transmitting wireless terminal are consecutive from the smallest sequence number of untransmitted frames and smaller than the smallest sequence number. This is a transmitted frame having a number and a frame that has not been received by the data transmission destination wireless terminal (a frame that has received a reception status notification that has not been received from the data reception side wireless line terminal). Note that untransmitted frames are transmitted by changing the channel / mode even if they are already in the transmission queue of one MAC processing unit (the MAC processing unit before the change) before the channel / mode change. There are no restrictions.

  Normally, in the IEEE802.11 wireless LAN, when retransmitting a frame, a retry bit in the frame control field of the MAC header is set, but this is the same as when a retry bit frame is received. This is in order to confirm a duplicate of whether or not a frame has been received. In this regard, in this embodiment, the frame of the missing portion as shown in FIG. 8 and the frame that has arrived or has not been confirmed as shown in FIG. 9 are given up in another channel / mode. There is no need to perform transmission processing such as setting a retry bit and retransmitting these frames in the previous MAC processing unit. In other words, in this embodiment, since the data transmission side previously prevents duplicate reception in different channels / modes, transmission processing is performed such that transmission is performed with a retry bit set in the change destination channel / mode. There is no need. Of course, this is not the case when a frame is retransmitted in the same channel / mode as the change source, and a retry bit is set.

(Effect of the first embodiment)
<1>
When the frame transmission is changed between the first transceiver and the second transceiver, the channel information corresponding to the change-destination transmitter / receiver to the receiving wireless terminal and the transmission of the frame transmitted by the change-destination transmitter / receiver are started. By notifying the sequence number, information necessary for arranging the frame order at the receiving wireless terminal is given, and this allows flexible movement of the transmission frame between the first transceiver and the second transceiver Will be able to change. Therefore, it becomes possible to flexibly cope with a sudden disconnection of the communication link in one channel.

<2>
By limiting the frames that can be retransmitted by the change-destination transceiver, it is possible to prevent duplicate reception in different channels / modes at the reception-side wireless terminal in advance by the operation of the transmission-side wireless terminal. As a result, the receiving-side wireless terminal does not need to manage duplicate frames having different sequence numbers and overlapping data contents between the first transceiver and the second transceiver.

<3>
By including the channel information corresponding to the frame change destination transceiver in the change notification frame, it is possible to clearly indicate the channel to be received in the future to the receiving wireless terminal, and the receiving wireless terminal transmits and receives data corresponding to the specified channel. The vessel can be specified. The reception-side wireless terminal can make preparations for frame reception. That is, the receiving wireless terminal can receive the frames transmitted by switching between channels / modes in order. This means that even when the transmission order is changed in the MAC layer, it is possible to return the order in the MAC layer without depending on the sequence in the upper layer.

<4>
The transmitting side wireless terminal can reduce the burden of frame preparation just before the access control unit (the part close to the 1/2 PHY processing unit in each 1/2 MAC processing unit). The movement of the transmission frame can be flexibly performed, and the reception-side wireless terminal can prevent the processing from being complicated when the reception frames from different frequency bands / channels are rearranged in the order of transmission. Therefore, it becomes possible to flexibly cope with a sudden disconnection of the communication link in one frequency band / channel. In addition, the reception side wireless terminal can release the frequency band / channel buffer that is no longer used due to the notification from the transmission side wireless terminal, thereby improving the efficiency of memory utilization.

<5>
By extracting channel information corresponding to the frame change destination transmitter / receiver from the change notification frame and specifying the exclusive channel as the change source channel, notification of the change source channel information may be omitted at the transmitting wireless terminal it can. Accordingly, the change notification frame length can be shortened, the usage rate of the wireless medium can be reduced, and high efficiency can be achieved.

(Second embodiment)
Since the second embodiment is based on the first embodiment, the following description will focus on differences from the first embodiment.

  The second embodiment differs from the first embodiment in that the change notification frame is transmitted in the change destination channel / mode instead of including the change destination channel / mode information in the channel / mode change notification frame. It is to be.

  For example, the channel / mode change notification frame represented as “Mg” in FIG. 7 used in the first embodiment is transmitted in the channel / mode to be changed. By defining in this way, it is not necessary to include information on the channel / mode to be changed in the change notification frame. As described in the first embodiment, it is assumed that the channel / mode is changed when it is in a situation inappropriate for communication such as a large number of dropped frames in the currently used channel / mode. The earlier channel / mode can be expected to establish a more suitable communication link with the receiving wireless terminal than before the change. Therefore, by transmitting the change notification frame in the channel / mode of the change destination, it can be expected that the reception-side wireless terminal reliably receives the change notification frame.

  Also, as described in the first embodiment, a channel / mode change notification frame is transmitted to the receiving wireless terminal, a response frame is received, and then a data frame is transmitted in the channel / mode to be changed. By doing so, it is possible to change the channel / mode after knowing that the receiving wireless terminal has surely received the change notification frame (note that the response frame is an Ack frame for the change notification frame). Alternatively, if the receiving wireless terminal returns a response management frame, the response management frame may be used. If no response frame is received, the transmitting wireless terminal reviews whether or not the channel / mode has been changed, stops changing the channel / mode according to the result of the examination, and transmits (retransmits) the data frame in the same channel / mode. ) May be performed. In this way, the data frame can be transmitted to the receiving wireless terminal by a more reliable method.

  The receiving-side wireless terminal that has received the change notification frame transmits a response frame, and the corresponding channel / mode of the transceiver that has received the change notification frame is changed in the future to which the corresponding data frame is transmitted. Recognize when it becomes channel / mode. For example, in the example of FIG. 7, since the change notification frame is received by the second transceiver, it is recognized that the data frame of the TID will be transmitted in the future by the second channel / mode corresponding to the second transceiver. To do. Then, as described in the first embodiment, a series of processing such as operation of a reordering buffer for data frame reception is performed.

(Effect of the second embodiment)
According to the present embodiment, by transmitting the change notification frame in the change destination channel / mode, it is not necessary to put information on the change destination channel / mode in the change notification frame. As a result, it is possible to further shorten the change notification frame, reduce the usage rate of the wireless medium, and achieve high efficiency. Also, assuming that the channel / mode is changed when the currently used channel / mode is in an inappropriate communication situation, the destination channel / mode is more on the receiving side than before the change. Since it can be expected that a more preferable communication link can be established with the wireless terminal, it can be expected that the data-side wireless terminal reliably receives the change notification frame.

  In addition, by receiving a response frame in response to a channel / mode change notification frame and then transmitting a data frame in the channel / mode to be changed to, the receiving wireless terminal reliably receives the change notification frame. It is possible to change the channel / mode after knowing that this has been done. If no response frame is received, the transmitting wireless terminal reviews whether or not the channel / mode has been changed, and the data frame in the original same channel / mode is stopped according to the result of the examination, and the channel / mode change is stopped. By retransmitting the data frame, the data frame can be transmitted to the receiving wireless terminal by a more reliable method.

(Third embodiment)
Since the third embodiment is based on the first embodiment, the description below will focus on differences from the first embodiment.

  The third embodiment differs from the first embodiment in that the channel / mode change notification frame corresponds to the change source channel / mode, strictly speaking, the change source transceiver in the transmission side wireless terminal. Information.

  For example, in the example of FIG. 7 used in the first embodiment, in this embodiment, since the first channel / mode is changed to the second channel / mode, the channel / mode represented by “Mg” is displayed. In the change notification frame, the fact that the first channel / mode is the change source channel / mode is entered.

  By doing so, the receiving-side wireless terminal that has received the change notification frame can easily specify the corresponding change source transceiver directly from the change source channel / mode information specified in the change notification frame. In other words, processing to determine which transceiver has exchanged (transmitted / received) the same TID data frame so far, and exclusive transmission / reception of the transceiver corresponding to the change destination channel / mode from the change destination channel / mode information There is no need to perform processing such as grasping the vessel. In particular, when there are three or more transceivers corresponding to different channels / modes, the process of specifying the source transceiver is simplified. After specifying the change destination transceiver, the processing described in the first embodiment can be performed on the change source transceiver.

(Effect of the third embodiment)
According to the present embodiment, by including the change source channel / mode information in the change notification frame, the receiving wireless terminal that has received the change notification frame receives the change source channel / mode information specified in the change notification frame. The transmitter / receiver of the change source can be easily identified directly. In other words, it is necessary to know which transceiver has exchanged (transmitted / received) the same TID data frame until now, and exclusive transmission / reception of the transceiver corresponding to the change destination channel / mode from the change destination channel / mode information. There is no need to grasp the vessel. In particular, when there are three or more transceivers corresponding to different channels / modes, the process of specifying the source transceiver is simplified.

(Fourth embodiment)
Since the fourth embodiment is based on the first embodiment, the description below will focus on differences from the first embodiment.

  The difference of the fourth embodiment from the first embodiment is that in the first embodiment, the information of the transmission start sequence number for starting transmission in the channel / mode to be changed is described in the change notification frame. In the fourth embodiment, an operation that can be omitted with respect to the transmission start sequence number is provided.

  In the terminal configuration of FIG. 6 of the first embodiment, when a frame is moved from the first MAC processing unit 11 to the second MAC processing unit 21 and the second MAC processing unit 21 reassigns the sequence number (or When the frame is moved from the second MAC processing unit 21 to the first MAC processing unit 11 and the sequence number is reassigned by the first MAC processing unit 11, the sequence number assignment unit initializes the sequence number to 0 Suppose that Or, even if it is not 0, another fixed sequence number is assigned as a default value. When it is guaranteed between the transmitting and receiving terminals that such an operation is surely performed, it is not necessary to put a transmission start sequence number for starting transmission in the change destination channel / mode in the change notification frame, and can be omitted. . In order to match the recognition of the default value between the wireless terminals, the default value may be notified when setting for the Block Ack mechanism is performed between the wireless terminals. If the length of the setting frame is limited to, for example, bytes, it is possible that unused fields (reserved fields) have been left, and if such fields can be used, communication efficiency will be improved. be able to.

  Referring to FIG. 7, in the present embodiment, in the channel / mode change notification frame represented as “Mg”, information indicating that the second channel / mode to be changed starts from sequence number 1 ( For example, when the transmitting wireless terminal moves a frame between the first and second transceivers 10 and 20, the sequence number at the destination is set. When re-adding from 0, frames with sequence numbers 2 to 5 in the first channel / mode are sequentially assigned sequence numbers 0 to 3 in the second channel / mode to be changed.

  The receiving wireless terminal that has received the change notification frame determines that the transmission start sequence number in the second channel / mode to be changed is a default value, which is 0 here, and is described in the first embodiment hereinafter. Process.

(Effect of the fourth embodiment)
According to the present embodiment, it is not necessary to include the transmission start sequence number in the change destination transceiver in the channel / mode change notification frame by setting the transmission start sequence number in the change destination transceiver to the default value. Thereby, the change notification frame length can be shortened, the usage rate of the wireless medium can be reduced, and high efficiency can be achieved.

  Also, since the channel / mode change is performed under the condition that the start sequence number is returned to the default value, the transmitter / receiver at the receiving wireless terminal does not need to include the transmission start sequence number of the destination transceiver in the change notification frame. It is possible to perform a reception process corresponding to the change.

  Also, when using frame exchange for setting in order to match the recognition of the default value between wireless terminals, for example, if the information can be put in an empty field in the setting frame, communication efficiency can be improved. it can.

(Fifth embodiment)
Since the fifth embodiment is based on the first embodiment, the description below will focus on differences from the first embodiment.

  The fifth embodiment is different from the first embodiment in that the transmission start sequence number in the change destination channel / mode is not notified in the change notification frame, but transmission is started in the change destination channel / mode. The difference between the sequence number in the frame change source channel / mode and the transmission start start sequence number is notified.

  Hereinafter, this will be described with reference to FIG. 10 in which FIG. 8 used in the first embodiment is modified for the fifth embodiment.

  In FIG. 10, the transmitting side wireless terminal transmits a data frame with sequence numbers 11 to 15 in the first channel / mode and receives a BA frame with a reception status indicating that data frames with sequence numbers 11 and 13 have been received. Receive from. In the reordering buffer 30 of the receiving wireless terminal, assuming that the minimum sequence number of standby is 11, the frame of sequence number 11 is sent to the process of passing from the MAC layer to the upper layer (LLC layer), and the minimum sequence number of standby is set. 12

  Here, the transmitting side wireless terminal decides to switch to the second channel / mode to perform transmission, and in order from the frame of sequence number 12 that has not been received in the first channel / mode, the second channel / mode It will be sent by.

  In order to transmit the unreceived sequence numbers 12, 14, 15 in the first channel / mode in the second channel / mode, the second MAC processing unit 21 from the transmission queue 13 of the first MAC processing unit 11 is transmitted. The frame is moved to the transmission queue 23. The data frame of sequence number 12 in the first MAC processing unit 11 is changed to sequence number 1 in the second MAC processing unit 21, and transmission is started from sequence number 1. Therefore, the difference between the sequence number 12 in the first MAC processing unit 11 and the sequence number 1 in the second MAC processing unit 21 of the data frame, in this case, −11 is entered in the channel / mode change notification frame ( In FIG. 10, “SN deviation = −11” is indicated).

  In the first embodiment, the receiving-side wireless terminal that has received the change notification frame raises all received frames in the reordering buffer 30 to the upper layer and then notifies the minimum sequence number in the frame waiting state. An operation to set the start sequence number was performed. On the other hand, in the present embodiment, when the received data frame is raised to the upper layer from the change destination transceiver (here, the second MAC processing unit 21) to the reordering buffer 30 in the common MAC processing unit 2, Based on the notified difference value, a correction process of the sequence number of the received data frame is added (in FIG. 10, “an instruction to reorder by correcting SN by +11”). In order to realize this, a correction processing block for passing a received frame may be added on the interface between the second MAC processing unit 21 and the common MAC processing unit 2 in FIG. A correction processing block may be provided on the second MAC processing unit 21 side. Alternatively, a correction processing block may be provided on the common MAC processing unit 2 side.

  In addition, in order to cope with the case where the change-destination transceiver is the first transceiver 10, the same processing is performed for passing the received data frame from the first transceiver 10 to the common MAC processing unit 2 in the same manner. The part to be performed (correction processing block) is necessary.

  After transmitting the channel / mode change notification frame (after receiving a response if a response is required), the transmitting wireless terminal transmits data frames with sequence numbers 1, 3, and 4 in the second channel / mode. Send. These correspond to the data frames of sequence numbers 12, 14, 15 in the first channel / mode, respectively.

  The receiving side wireless terminal that has normally received sequence numbers 1, 3, and 4 in the second channel / mode notifies the transmitting side wireless terminal of the fact with a BA frame and raises the received frame to the reordering buffer 30. At that time, the receiving wireless terminal corrects the received sequence number with the notified difference value. Here, the data frames of sequence numbers 1, 3, and 4 are corrected by the difference value “−11” to be sequence numbers 12, 14, and 15, and are put into the reordering buffer 30. Since the sequence number 12 that could not be received in the first channel / mode was received in the second channel / mode, the frames are passed in the order of sequence numbers 12 to 13, 14, and 15 (note that the sequence number 13 Has been received on the first channel / mode).

  In this case, the data frame notified as unreceived in the first channel / mode in the receiving wireless terminal is retransmitted in the second channel / mode, but the frame notified as already received is transmitted in the second channel / mode. You may retransmit in mode.

  For example, the frame of sequence number 13 in the first channel / mode may be retransmitted as sequence number 2 in the second channel / mode. In this case, the frame received in the second channel / mode and having the sequence number corrected to 13 is discarded because it is already stored in the reordering buffer 30. Therefore, there is no problem even if this is done.

  Similarly, there is no problem when retransmission is performed in the second channel / mode in order from the frame of sequence number 11 in the first channel / mode. For example, when sequence number 0 is assigned to the frame of sequence number 11 in the second channel / mode, the difference is −11. In the receiving wireless terminal, the reordering buffer 30 has already raised the minimum sequence number for frame waiting to sequence number 12, and since the corrected sequence number 11 is smaller than the minimum sequence number 12 for standby, the sequence number 11 The frame is discarded, so there is no problem.

  As described above, there is no problem even if a frame that has already been received is retransmitted. However, in order to explicitly indicate the possibility of duplicate reception, it is desirable to transmit the above-described retry bit.

  As described above, as in the case of FIG. 9 used in the first embodiment, a frame / mode can be changed and retransmitted even for a frame that has been received by the receiving wireless terminal and has no confirmation.

  Generally expressing the processing of this embodiment, when the difference in sequence number between the change source and the change destination channel / mode is notified as Δ (−11 in the above example), the change destination channel For the frame received in the / mode, the process “sequence number−Δ” is performed. The reference for the difference is the change source in the above description, but any reference may be used as long as the same correction can be finally made. For example, if the reference is the change destination, in this example, the difference is 11 instead of −11, and correction processing of “sequence number + Δ” may be performed on the frame received in the change destination channel / mode.

  If the difference between the sequence number assigned by the source transceiver and the sequence number assigned by the destination transceiver is known before the channel / mode change (for example, fixed), the difference information is notified of the change. Instead of notifying with a frame, it may be notified in advance to the receiving wireless terminal. For example, when the setting for the Block Ack mechanism is performed between the transmitting-side wireless terminal and the receiving-side wireless terminal, if the difference value is notified, the difference information can be notified collectively by setting frame exchange. . If the length of the setting frame is limited to, for example, bytes, it is possible that unused fields (reserved fields) have been left, and if such fields can be used, communication efficiency will be improved. be able to. When the receiving wireless terminal receives the channel / mode change notification frame, it may perform the correction operation as described above using the difference value notified in advance.

(Effect of the fifth embodiment)
According to the present embodiment, the first embodiment is notified by notifying the difference value between the start sequence number of the frame that starts transmission at the change destination transceiver and the sequence number at the transmission source transceiver of the frame. Then, it becomes possible to retransmit a frame that could not be retransmitted by the change destination transceiver (change destination channel / mode) (in the first embodiment, it was possible to retransmit consecutively dropped frames up to untransmitted frames). ). For example, even a frame that has been dropped due to missing teeth or a frame that has been reliably received by the receiving wireless terminal and has not been confirmed can be retransmitted with the channel / mode changed.

  The receiving side wireless terminal can also correct the sequence number of the received frame by receiving the notification of the above difference value, so that the channel / mode to be changed (even if it is not a frame that is continuously dropped until an untransmitted frame) The reordered frames can be rearranged in order.

  If the difference between the sequence number assigned by the source transceiver and the sequence number assigned by the destination transceiver is known, the difference information is not notified in the change notification frame, but the setting frame exchange, etc. Can be notified in advance to the receiving wireless terminal. For example, if the information can be put in an empty field in the setting frame, the communication efficiency can be improved.

(Sixth embodiment)
Since the sixth embodiment is based on the first embodiment, the description below will focus on differences from the first embodiment.

  The sixth embodiment is different from the first embodiment in that the address of the wireless terminal used for data transmission / reception in the first embodiment is common among different channels / modes, but each channel / mode ( In other words, the wireless terminal address is changed in each transceiver. The wireless terminal address is a MAC address in the IEEE802.11 wireless LAN, and is entered in one of the address fields in the frame configuration of FIG.

  Alternatively, in the first embodiment, the traffic type (TID) of the data frame to be switched between different channels / modes is common, but in this embodiment, different TIDs are assigned to each channel / mode. It is.

  First, a case where the address of the wireless terminal is changed between channels / modes will be described.

  In this case, the wireless terminal address corresponding to each channel / mode is notified to the receiving wireless terminal. The notification may be included in a channel / mode change notification frame, but preferably, first, a wireless terminal address corresponding to each channel / mode is included when setting for frame exchange between wireless terminals. The channel / mode change notification frame may be included for confirmation.

  For example, in order to connect between a wireless base station and a wireless terminal as shown in FIG. 2, in an IEEE802.11 wireless LAN, an authentication frame is exchanged as an authentication process, and an association request frame and an association response frame are exchanged as an association process. Therefore, the wireless terminal address corresponding to each channel / mode is notified in one of these frame exchanges (the order of performing the Authentication process and the Association process is the security setting, the security setting is Depending on what to do). Since the association process notifies the capability of the wireless terminal (including the wireless base station), it is considered that notification in the frame exchange of this process is appropriate. In addition, between wireless terminals that are not wireless base stations, for example, when performing direct communication under a wireless base station, the IEEE802.11 wireless LAN uses a process called Direct Link Setup. Good. Alternatively, if a notification is made when the block Ack setting process is performed for actual data frame exchange, notification can be performed even between wireless terminals in a situation where no wireless base station is interposed as shown in FIG. .

  When notification is performed in one channel / mode (the channel / mode before the change), since the wireless terminal address is known in the channel / mode in which the notification is performed, such a notification field is not provided. Alternatively, as another corresponding channel / mode information, the MAC address information corresponding to the channel / mode may be entered and notified.

  In addition, in IEEE802.11 wireless LAN, when a BSS is constructed under a wireless base station as shown in Fig. 2, the ID in the BSS (ID assigned in the Association process when connecting to the wireless base station) Is assigned an Association ID (AID). The ID in the wireless communication group such as in BSS (in this case, it is not limited to AID but is used as a convenient identification ID of the wireless terminal in a certain communication group) is shorter than the MAC address, so wireless communication If group information is available separately, it can be used for efficiency instead of the MAC address of the wireless terminal. A notification method such as which MAC address corresponds in which channel / mode to the ID in such a wireless communication group may be adopted.

  In the receiving wireless terminal that has received the notification of the wireless terminal address corresponding to each channel / mode, a score board is provided in the transceiver corresponding to each channel / mode, and the BA frame is a wireless corresponding to each channel / mode. Sent using terminal address. However, the reordering buffer is the same for each transceiver (each wireless terminal address), and even if a data frame with a different (direct) source address is sent from each transceiver, these data frames are the same. The data frame is recognized as a data frame from the wireless terminal and is put in a common reordering buffer.

  Next, a case where a different traffic type (TID) is assigned for each channel / mode will be described.

  In IEEE802.11 wireless LAN, TID is mapped directly from the priority parameter in MA-UNITDATA.request primitive that instructs data transmission request from LLC layer to MAC layer. Therefore, it is normal that TID is different in each channel / mode. I can't think so much. However, if the TID is changed for each channel / mode due to differences in the propagation environment of each channel / mode and the handling of QoS policies, the address of the wireless terminal is different for each channel / mode. It is sufficient to notify the TID correlation between channels / modes in the same manner as in different cases.

(Effects of the sixth embodiment)
According to the present embodiment, by providing the notification method as described above, even when a different radio terminal address or a different traffic type is assigned to each channel / mode, the channel / mode for transmitting the data frame is changed. The data frames can be rearranged in the order in the receiving wireless terminal.

(Seventh embodiment)
The seventh embodiment is the same as the first to sixth embodiments in that sequence numbers are assigned to each channel / mode separately, but the reordering buffer is also provided separately for each channel / mode. This is different from the embodiment. In the present embodiment, the wireless terminal address of each channel / mode is common between the channels / modes, and the TID assignment is also common between the channels / modes. However, the same method as in the sixth embodiment is used. If applied, each can be changed.

  The configuration of the wireless terminal in the seventh embodiment is as shown in FIG. 11 with respect to the configuration of FIG. 6 shown in the first embodiment. The difference from FIG. 6 is that the reordering buffer is removed from the common MAC processing unit 2 and the reordering buffers 16 and 26 are individually provided in the MAC processing units 11 and 21, respectively. Although shown as connecting between the scoreboards 14, 24 and the reordering buffers 16, 26, this is a schematic representation of the flow of received data frames, during which other processing processes (e.g. A duplicate reception detection / discard processing block, a security processing block, etc.) may be interposed.

  The operation of the seventh embodiment will be described with reference to FIG. 12, corresponding to FIG. 8 in the first embodiment. Since the operation at the transmitting wireless terminal is the same as that of the first embodiment, the operation of the receiving wireless terminal will be mainly described.

  The receiving side wireless terminal normally receives the frames of sequence numbers 11 and 13 and transmits a BA frame of a delivery confirmation response thereto. The received frames of sequence numbers 11 and 13 are sent to the reordering buffer 16 (shown as “first reordering buffer” in FIG. 12) in the first MAC processing unit 11, and the sequence number 11 is the upper layer. Therefore, the reordering buffer 16 waits for a frame from the sequence number 12.

  When the receiving side wireless terminal receives the channel / mode change notification frame, the received frame in the reordering buffer 16 in the first MAC processing unit 11 corresponding to the source channel / mode (that is, the sequence number 13 here) Frame) is sent to the common MAC processing unit 2 to be passed to the upper processing. Here, the reordering buffer 30 in the first MAC processing unit 11 is reset because it will not receive a frame of the same traffic type (same TID) from the same wireless terminal. By using the reset reordering buffer 30 for other frames, resources (mainly memory) in the wireless terminal can be effectively used. Further, the score board 14 in the first MAC processing unit 11 may be reset as in the first embodiment. By receiving the change notification frame, the minimum sequence number in the frame waiting state in the reordering buffer 26 in the second MAC processing unit 21 is set to the start sequence number 1 described in the change notification frame. Here, as shown in FIG. 12, if the port for passing the data frame to the upper layer is switched from the first reordering buffer 16 to the second reordering buffer 26, the frames are more reliably transferred to the upper layer in order. Can pass.

  After that, when the receiving wireless terminal receives frames with sequence numbers 1 and 2 in the second channel / mode (corresponding to sequence numbers 14 and 15 in the first channel / mode, respectively), the second MAC processing unit 21 They are passed through the reordering buffer 26 to the upper level. As a result, when considering the first channel / mode, sequence numbers 11, 13, 14, and 15 can be raised in order.

  It is also possible to provide a common reordering buffer in the common MAC processing unit 2 in the wireless terminal configuration of FIG. In this case, when a change notification frame is received, all the received frames in the reordering buffer of the source MAC processing unit are raised through the common reordering buffer, and then the common reordering buffer and the destination MAC processing unit are reconfigured. Both the minimum sequence number of the frame waiting state with the ordering buffer may be set using the value in the change notification frame.

(Effects of the seventh embodiment)
According to this embodiment, even if the receiving-side wireless terminal has a reordering buffer for each channel / mode, frames transmitted by switching between the channels / modes can be received in order.

(Eighth embodiment)
Since the eighth embodiment is based on the seventh embodiment, differences from the seventh embodiment are mainly described below.

  The difference of the eighth embodiment from the seventh embodiment is the same as the fourth embodiment different from the first embodiment, and the transmission start sequence number in the channel / mode to be changed is the default value. Is set to As a result, in the eighth embodiment, as in the fourth embodiment, the notification of the transmission start sequence number in the change notification frame can be omitted.

  That is, in FIG. 12 used in the seventh embodiment, the start sequence number (“SN = 1 to Tx” ”part that starts transmission in the change destination channel / mode in the change notification frame represented as“ Mg ”. The configuration of the wireless terminal is as shown in Fig. 11 as in the seventh embodiment, but the operation of the wireless terminal as the data receiving side and the data transmitting side is the same as in the fourth embodiment. It is the same.

(Effect of 8th Embodiment)
According to the present embodiment, even when the reordering buffer is individually provided in the first transceiver and the second transceiver in the receiving wireless terminal, the transmission start sequence number of the change transceiver in the receiving wireless terminal The reception process corresponding to the change of the transmitter / receiver can be performed without notification.

(Ninth embodiment)
Since the ninth embodiment is based on the seventh embodiment, the description below will focus on differences from the seventh embodiment.

  The ninth embodiment is different from the seventh embodiment in that the fifth embodiment is different from the first embodiment, and the transmission start sequence number for starting transmission in the channel / mode to be changed is set. Rather than notifying, it is notifying the difference between the sequence number in the change source channel / mode of the transmission start frame by the change destination channel / mode and the transmission start sequence number.

  The operation of the ninth embodiment will be described with reference to FIG. Note that the operation of the transmitting wireless terminal is the same as that of the fifth embodiment, and a description thereof will be omitted.

  When receiving the change notification frame, the receiving wireless terminal corrects the state of the reordering buffer 16 in the first MAC processing unit 11 of the change source by using the sequence number difference (here, -11), and changes the change destination. To the reordering buffer 26 in the second MAC processing unit 21.

  That is, the reordering buffer 16 in the first MAC processing unit 11 is waiting for the frame with the sequence number 12 and the frame with the sequence number 13 has already been received. The corrected difference value is corrected and put into the reordering buffer 26 in the second MAC processing unit 21. Further, the minimum sequence number in the frame waiting state of the reading buffer 26 is set to a value (here, 1) obtained by correcting the minimum sequence number of the reordering buffer 16 at this time with the above difference value. As a result, in the reordering buffer 26, the sequence number 1 is in the frame waiting state, and the frame of the sequence number 2 has already been received. It is desirable to reset the reordering buffer 16 and the scoreboard 14 in the first MAC processing unit 11 that is the change source from the resource aspect in the wireless terminal.

  After that, when the receiving wireless terminal receives the frames of sequence numbers 1, 3, and 4 in the second channel / mode, the sequence numbers 1, 2, 3, and so on are sequentially received from the reordering buffer 26 in the second MAC processing unit 21. As a result, when considering the first channel / mode side, all frames of sequence numbers 11, 12, 13, 14, and 15 are received in order.

(Effect of the ninth embodiment)
According to the present embodiment, even when the reordering buffer is individually provided in the first transmitter / receiver and the second transmitter / receiver in the reception-side wireless terminal, the received frame sequence number is corrected by the notified difference value. Thus, the retransmitted frames after changing the channel / mode can be rearranged in order (even if they are not continuously dropped frames up to untransmitted frames).

(Tenth embodiment)
Since the tenth embodiment is based on the ninth embodiment, the description below will focus on differences from the ninth embodiment.

  The difference between the tenth embodiment and the ninth embodiment is that, as mentioned in the seventh embodiment, a reordering buffer is provided separately for each channel / mode, and the common MAC processing unit 2 is more common. A reordering buffer is provided.

  The operation of the tenth embodiment will be described with reference to FIG. Note that the operation of the transmitting wireless terminal is the same as that of the fifth embodiment, and a description thereof will be omitted. At the start of the operation, the minimum sequence number for frame waiting in the reordering buffer of the common MAC processing unit 2 is set to the same value as the minimum sequence number for frame waiting in the reordering buffer 16.

  When the receiving side wireless terminal receives the change notification frame, all the received frames of the reordering buffer 16 in the first MAC processing unit 11 of the changing source are all reordering buffers in the common MAC processing unit 2 (in FIG. To the ordering buffer ”). Here, as in the seventh embodiment, the reordering buffer 16 in the first MAC processing unit 11 (referred to as “first lower-order reordering buffer” in FIG. 14) is the same traffic type from the wireless terminal in the future. Since a frame with the same TID is not received, it is preferable that the frame is reset and used for other frames. Thereby, resources (mainly memory) in the wireless terminal can be effectively used.

  Then, the minimum sequence number of the frame waiting state in the reordering buffer 26 (represented as “second lower-order reordering buffer” in FIG. 14) of the second MAC processing unit 21 to be changed is set. Specifically, the minimum sequence number in the frame waiting state in the reordering buffer of the common MAC processing unit 2 (or the minimum sequence number in the waiting state of the reordering buffer 16) is corrected with the difference value notified in the change notification frame. Set to the same value (12-11 = 1 here). Then, when raising the received frame from the reordering buffer 26 of the second MAC processing unit 21 to be changed to the common MAC processing unit 2, the difference value (here, -11) indicated by the change notification frame And correct it in the opposite direction.

  Thereafter, when frames with sequence numbers 1, 3, and 4 are received in the second channel / mode, the frame with sequence number 1 is transferred from the reordering buffer 26 of the second MAC processing unit 21 to the common MAC processing unit 2 with the sequence number 12 (It is raised as a frame of (1-(-11) or 1 + 11). Since the frame of sequence number 12 is received in the common MAC processing unit 2, the frame of sequence number 12 has already passed through the first MAC processing unit 11. The frame with the sequence number 13 received in the above is raised to the upper level, and the minimum sequence number in the frame waiting state is raised to 14.

  A value (14−11 = 3) obtained by correcting the minimum sequence number 14 in the frame waiting state with the difference value is set as the minimum sequence number in the frame waiting state of the reordering buffer in the second MAC processing unit 21. As a result, the reordering buffer 26 of the second MAC processing unit 21 skips waiting for the frame with the sequence number 2, and the frame with the sequence number 3 has been received. Change the sequence number to 14 or 15 and raise it to the reordering buffer of the common MAC processing unit 2.

  Since the minimum sequence number in the frame waiting state is 14 in the reordering buffer of the common MAC processing unit 2, the frames with the sequence numbers 14 and 15 are transferred to the next process to be raised to the upper layer.

  As a result, when considering the first channel / mode side, all frames of sequence numbers 11, 12, 13, 14, and 15 are received in order.

(Effect of 10th Embodiment)
According to the present embodiment, the channel / mode is changed even in the terminal configuration in which the first transmitter / receiver and the second transmitter / receiver have separate reordering buffers, and there is a common reordering buffer above them. The retransmitted frames can be rearranged in order (even if they are not consecutively dropped frames until the untransmitted frames).

(Eleventh embodiment)
The eleventh embodiment differs from the first to sixth embodiments in that the sequence number is shared between channels / modes. Clearly the TID assignment is common between channels / modes. Each wireless terminal address is also assumed to be common between channels / modes. When the sequence number is made common between channels / modes, it is unlikely that the radio terminal address will differ between channels / modes. However, if the same method as in the sixth embodiment is applied, the channel / mode will be different between channels / modes. It is also possible to change the wireless terminal address.

  The configuration of the wireless terminal is as shown in FIG. 15 as compared to FIG. 6 in the first embodiment. The common MAC processing unit 2 has a sequence number assigning unit 31, and a transmission frame is assigned to the first MAC processing unit 11 or the second MAC processing unit 21 after being assigned a sequence number through the assigning unit 31. . Even when the frame transmission source is changed between the first MAC processing unit 11 and the second MAC processing unit, the frames in the transmission queue of the original MAC processing unit remain the sequence numbers already assigned. It is placed in the transmission queue of the MAC processing unit to be changed and transmitted.

  The operation of the eleventh embodiment will be described with reference to FIG.

  The transmitting side wireless terminal transmits the frames of sequence numbers 1 to 5 in the first channel / mode. The transmitting wireless terminal is notified by the BA frame that the frames of sequence numbers 1 and 3 have been received from the receiving wireless terminal, and transmits the frames of sequence numbers 2, 4, and 5 in the second channel / mode. To decide. Here, the sequence number of each frame is not changed and is the same value as used in the first channel / mode. The transmitting wireless terminal transmits a change notification frame in order to change the channel / mode for transmitting the frame. In the change notification frame, information indicating that transmission is performed in the second channel / mode and transmission is started from sequence number 2 is included as information.

  When the receiving side wireless terminal receives the change notification frame, it determines whether the minimum sequence number of the standby in the reordering buffer 30 of the common MAC processing unit 2 is less than the sequence number entered in the change notification frame. If there is, the frame is not transmitted even if the channel / mode is changed, and the next sequence number is shifted. If the frame with the shifted sequence number has already been received, the frame is transferred to the upper layer, and the minimum sequence number for standby is further increased. If the shifted sequence number is still less than the sequence number in the change notification frame, the same processing as described above is performed.

  In the receiving wireless terminal, it is also desirable to reset the score board 14 of the first MAC processing unit 11 that is the change source. This is because by resetting the scoreboard 14, the reset scoreboard 14 can be utilized for receiving a frame of another wireless terminal or another TID as in the first embodiment.

  In addition, as described in the first embodiment, when a method called partial state BA in IEEE802.11n is applied, a free scoreboard that holds a reception status when receiving a frame from a new wireless terminal, etc. When there is no score, you can reset and use the scoreboard that already holds the status. However, as described above, by resetting a scoreboard that is known to be no longer used, if there are multiple scoreboards in partial state BA, the algorithm for selecting which one to reset is already unused. It can be simplified as the scoreboard is preferentially selected.

  After that, when frames with sequence numbers 2, 4, and 5 are received from the transmitting wireless terminal in the second channel / mode to be changed, the receiving wireless terminal returns a BA frame indicating that these frames have been received, and changes The received frame from the second MAC processing unit 21 is raised to the reordering buffer 30 of the common MAC processing unit 2. In the reordering buffer, each frame is raised to an upper layer (here, LLC layer) in the order of sequence number 2, sequence number 3 already received in the first channel / mode, and so on. As a result, the frames are received in order of sequence numbers 1, 2, 3, 4, and 5.

(Effect of the eleventh embodiment)
According to the present embodiment, even when a frame assigned a sequence number in common is transmitted from different transceivers, by transmitting a transceiver change notification frame to the receiving wireless terminal, the receiving wireless terminal uses it. The buffer (scoreboard) in the lost frequency band / channel can be released to improve the efficiency of memory usage. In addition, the receiving side wireless terminal knows in advance the sequence number that is not transmitted by the transmitting side wireless terminal by using the change notification frame, thereby eliminating the discrepancy in the recognition of the transmission status between the transmitting side and the receiving side, so that the receiving side is in an optimal standby state. Can be.

(Twelfth embodiment)
Since the twelfth embodiment is based on the eleventh embodiment, differences from the eleventh embodiment will be mainly described below.

  The twelfth embodiment is different from the eleventh embodiment in that a reordering buffer is also provided in each transceiver corresponding to a different channel / mode.

  The configuration of the wireless terminal is as shown in FIG. Reordering buffers 16 and 26 are provided in each of the first MAC processing unit 11 and the second MAC processing unit 21 with respect to FIG. 15 which is the wireless terminal configuration in the eleventh embodiment.

  In such a case, how to perform the process of rearranging the frames in the order of the sequence numbers at the receiving wireless terminal will be described with reference to FIG. Since the operation of the transmitting wireless terminal is the same as that of the eleventh embodiment, it is omitted here.

  At the receiving wireless terminal, the reordering of the common MAC processing unit 2 for frames received in order by the reordering buffer 16 of the first MAC processing unit 11 (represented as “first lower ordering buffer” in FIG. 18). Buffer 30 (shown as “upper reordering buffer” in FIG. 18). That is, frames received in order by the lower ordering buffer are raised to the upper reordering buffer. (This is the same in other embodiments when the MAC processing unit and the common MAC processing unit have reordering buffers).

  When the receiving side wireless terminal receives the channel / mode change notification frame, the reordering buffer 16 of the first MAC processing unit 11 that is the source of the change performs the common MAC processing on the frame of the sequence number + 1 or more notified by the change notification frame. Raise to part 2 reordering buffer 30. At the same time, it is desirable to reset the scoreboard 14 of the first MAC processing unit 11 as in the other embodiments described above. Also, the sequence notified by the change notification frame of the minimum sequence number in the frame waiting state of the reordering buffer 26 (shown as “second lower-order reordering buffer” in FIG. 18) in the second MAC processing unit 21 Set to a number. In the above description, the sequence number + 1 or more is described. However, since there is no problem even if duplicate reception is performed, a frame having a sequence number or more may be simply raised to the reordering buffer 30 of the common MAC processing unit 2.

  After that, when sequence numbers 2, 4, and 5 are received in the second channel / mode to be changed, the frame of sequence number 2 is placed in the reordering buffer 30 of the common MAC processing unit 2, and the frame of sequence number 2 and The frame of sequence number 3 that has already been received in the first channel / mode is passed from the reordering buffer 30 to the next process to be raised to the upper layer (LLC layer). The minimum sequence number in the frame waiting state in the reordering buffer 30 of the common MAC processing unit 2 is 4.

  The updated minimum sequence number 4 is set as the minimum sequence number in the standby state in the reordering buffer 26 in the second MAC processing unit 21 as in the tenth embodiment.

  In this embodiment, the difference correction as in the tenth embodiment may not be performed. Then, the frames of sequence numbers 4 and 5 are sequentially raised from the reordering buffer 26 of the second MAC processing unit 21 to the reordering buffer 30 of the common MAC processing unit 2. As a result, frames of sequence numbers 1, 2, 3, 4, and 5 are received in order.

(Effect of the twelfth embodiment)
According to the present embodiment, the terminal configuration is such that a frame assigned a sequence number in common is transmitted from different transceivers, each transceiver has a reordering buffer and a reordering buffer as a common MAC processing unit above it. However, by sending a transceiver change notification frame to the receiving wireless terminal, the receiving wireless terminal releases the buffer (scoreboard) in the frequency band / channel that is no longer used, and the efficiency of memory utilization Can be achieved. In addition, the receiving side wireless terminal knows in advance the sequence number that is not transmitted by the transmitting side wireless terminal by using the change notification frame, thereby eliminating the discrepancy in the recognition of the transmission status between the transmitting side and the receiving side, so that the receiving side is in an optimal standby state. Can be.

(13th embodiment)
Since the thirteenth embodiment is based on the eleventh embodiment, differences from the eleventh embodiment will be mainly described below.

  The thirteenth embodiment differs from the eleventh embodiment in that each transmitter / receiver has a reordering buffer individually instead of having a common reordering buffer.

  The configuration of the wireless terminal of this embodiment is as shown in FIG. The common MAC processing unit 2 is not provided with a reordering buffer, and the first MAC processing unit 11 and the second MAC processing unit 21 are each provided with a reordering buffer.

  An operation related to frame reception in such a wireless terminal configuration will be described with reference to FIG. Since the operation of the transmitting wireless terminal is the same as that of the eleventh embodiment, it is omitted here.

  When the receiving side wireless terminal receives the frames of sequence numbers 1 and 3 in the first channel / mode, the frame of sequence number 1 is raised from the reordering buffer 16 of the first MAC processing unit 11. The reordering buffer 16 enters a standby state from the sequence number 2 and holds the frame of the sequence number 3.

  When a channel / mode change notification frame is received, the state of the reordering buffer 16 of the first MAC processing unit 11 that is the source of change is changed to the second MAC processing unit 21 that is the destination of change in the same manner as in the ninth embodiment To the reordering buffer 26. More specifically, if there is a received frame less than the sequence number notified in the change notification frame (less than 2 in this case), the received frame is raised to the higher order, and then the state of the reordering buffer 16 (that is, the transmission start sequence number) The larger frame and the minimum sequence number in the waiting state) are transferred to the reordering buffer 26 of the second MAC processing unit 21 to be changed.

  As described above, it is desirable to reset the reordering buffer 16 and the scoreboard 14 of the first MAC processing unit 11 as the change source after this. Unlike the ninth embodiment, it is not necessary to correct the frame sequence number in this embodiment. The minimum sequence number in the frame waiting state of the reordering buffer 26 of the second MAC processing unit 21 to be changed is 2 in FIG.

  After that, when frames with sequence numbers 2, 4, and 5 are received from the second channel / mode, the received frames are placed in the reordering buffer 26 of the second MAC processing unit 21, and are sequentially raised from there. . As a result, frames of sequence numbers 1, 2, 3, 4, and 5 are received in order.

(Effect of the thirteenth embodiment)
According to the present embodiment, a transmitter / receiver that transmits a frame that is commonly assigned a sequence number from different transmitters / receivers, and that transmits from the transmitting wireless terminal even in a terminal configuration in which each transmitter / receiver has a reordering buffer. With the change notification frame, the reception-side wireless terminal can rearrange the reception frames in order. It is also possible to increase the efficiency of memory utilization by releasing buffers (reordering buffers, scoreboards) in frequency bands / channels that are no longer used by the receiving wireless terminal. In addition, by knowing in advance the sequence number that is not transmitted by the transmitting wireless terminal on the receiving side using the change notification frame, it is possible to eliminate the discrepancy in the recognition of the transmission status between the transmitting side and the receiving side, and to set the optimal standby state on the receiving side Can do.

(14th embodiment)
Since the fourteenth embodiment is based on the first to thirteenth embodiments, the following description will focus on points supplementing the first to thirteenth embodiments.

  The point that the fourteenth embodiment supplements the first to thirteenth embodiments is that the first transceiver 10 and the second transceiver 20 of the wireless terminal are a millimeter wave transceiver and a microwave transceiver, respectively. is there.

  Here, the millimeter wave refers to an electromagnetic wave having a wavelength of the millimeter (mm) order, and is an electromagnetic wave having a frequency band of 30 GHz or more and less than 300 GHz. Specifically, the millimeter wave transmission / reception circuit is, for example, an electromagnetic wave transmission / reception circuit in the 57-66 GHz band.

  Here, the microwave refers to an electromagnetic wave having a wavelength of, for example, an order of centimeter (cm) or more, and is an electromagnetic wave having a frequency band of 300 MHz or more and less than 30 GHz. Specifically, the microwave transmission / reception circuit is, for example, an electromagnetic wave transmission / reception circuit in a 5 GHz band or a 2.4 GHz band.

  In particular, in millimeter wave communication, depending on the antenna design, omni-directional transmission / reception cannot be performed, and it may be quasi-omni-directional. In this case, even if transmission and reception can generally be performed with microwaves, the direction in which transmission and reception can be performed with millimeter waves is limited.

  In this embodiment, as described above, in FIG. 6 used as the wireless terminal configuration in the first embodiment, the first transmitter / receiver is a millimeter-wave band transmitter / receiver, and the second transmitter / receiver is a microwave band. Use a transmitter / receiver.

  However, the present invention is not limited to this. For example, the first transmitter / receiver described above may be a 5 GHz band transmitter / receiver, and the second transmitter / receiver may be a 2.4 GHz band transmitter / receiver.

  That is, generally, the higher the frequency band, the greater the attenuation of electromagnetic waves (radio waves) with respect to distance. The wireless terminal of the present invention may be a wireless terminal having at least two electromagnetic wave transmission / reception units with such a frequency band difference, in other words, a difference in radio wave attenuation characteristics, or a difference in coverage area.

  For example, the frequency used for communication is low and the attenuation of radio waves is small, that is, the transmitter / receiver in the frequency band with the wider coverage area is used as the second transmitter / receiver, the frequency used for communication is high and the attenuation of radio waves is large, that is, the coverage area is narrow The transceiver in the other frequency band is made the first transceiver.

  In general, the higher the frequency band is, the easier it is to secure a wide band, and transmission at a high transmission rate can be expected. Conversely, the lower the frequency band, the more difficult it is to secure a narrow band and the tendency to stay at a low transmission rate. I can say that. Combined with these characteristics, the transmitter / receiver in the frequency band with a wide coverage area but only a narrow band and a low transmission rate is used as the second transmitter / receiver, and the frequency band with a narrow coverage area but a wide band and a high transmission rate can be secured. The transceiver may be the first transceiver.

  In such a case, a channel / mode change notification frame is transmitted from the second transceiver.

(Effect of 14th Embodiment)
According to this embodiment, when the characteristics of wireless communication are different due to different frequency bands used by the first transceiver and the second transceiver, the change notification frame is sent on the side where the communication link establishment accuracy is high. By transmitting, it is possible to guarantee notification to the receiving wireless terminal.

(Fifteenth embodiment)
Since the fifteenth embodiment is based on the first to fourteenth embodiments, the following description will focus on points supplementing the first to fourteenth embodiments.

  The point that the fifteenth embodiment supplements the first to fourteenth embodiments relates to the operation of notifying the upper layer of the transmission status at the transmitting side wireless terminal.

  Hereinafter, the present embodiment will be described with reference to FIG.

  As shown in FIG. 21A, in the IEEE802.11 wireless LAN, when data to be transmitted from the upper layer (for example, LLC layer) is passed to the MAC layer, a primitive called MA-UNITDATA.request is used. The MAC layer notifies the upper layer of the transmission status for this data using a primitive MA-UNITDATA.confirm.

  For example, the MAC layer first checks whether the passed data is data that can be transmitted, and if it cannot be transmitted at this stage, it generates MA-UNITDATA.confirm to notify that in the upper layer of the MAC layer. And notify the upper layer.

  In addition, for data that does not require a delivery confirmation response for transmission processing at the MAC layer, when the data transmission processing is performed, the fact that transmission was successful is placed in MA-UNITDATA.confirm and notified to the upper layer .

  For data that requires a delivery confirmation response, if a response to the data is received (including when it is received as a result of retransmission), the upper layer is notified in MA-UNITDATA.confirm that the transmission was successful.

  For data that requires a delivery confirmation response, if the response to the data has not been retransmitted a predetermined number of times, the transmission process is stopped, and the upper layer is notified in MA-UNITDATA.confirm that the transmission has failed. To do.

  Here, as shown in FIG. 21 (B), consider the case of dealing with a plurality of channels / modes as handled in the above embodiments (in the case of multi-mode from the middle of the MAC).

  For example, when the first MAC processing unit and the second MAC processing unit are separated, in such a multi-channel / multi-mode wireless terminal, either the first MAC processing unit or the second MAC processing unit must be To stop sending itself (without changing the channel / mode) or if the transmission is successful (if a delivery acknowledgment is required, a delivery acknowledgment is received) , MA-UNITDATA.confirm is issued.

(Effect of 15th Embodiment)
According to the present embodiment, even in a wireless terminal that supports a plurality of channels / modes in the middle of the MAC layer, a transmission status notification can be returned in response to a data transmission request from an upper layer.

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

2: Common MAC processing unit (frame distribution unit)
10: 1st transmission / reception part (1st communication part)
20: 2nd transmission / reception part (2nd communication part)
11: First MAC processing unit 12: Sequence number assigning unit (first sequence number assigning means)
13: Transmission queue (first transmission queue)
14: Scoreboard (first reception status storage unit)
15: First PHY processing unit 16: Reordering buffer (first individual reordering buffer)
18: First antenna 21: Second MAC processing unit 22: Sequence number assigning unit (second sequence number assigning means)
23: Transmission queue (second transmission queue)
24: Scoreboard (second reception status storage unit)
25: Second PHY processing unit 26: Reordering buffer (second individual reordering buffer)
28: Second antenna 30: Reordering buffer (common reordering buffer)
31: Sequence number assignment unit 201, 202: Wireless terminal (including wireless base station)
101: Radio base station

Claims (21)

A wireless terminal that communicates with other wireless terminals,
A frame distribution unit for performing a distribution process of data frames to be transmitted to the other wireless terminals;
First sequence number assigning means for assigning a sequence number to an input data frame, and transmitting the data frame to which the sequence number is assigned to the other wireless terminal in a first channel or a first mode. 1 communication unit;
Second sequence number assigning means for assigning a sequence number to the input data frame, and sending the data frame assigned the sequence number by the second sequence number assigning means to the other radio terminal in the second channel Or a second communication unit that transmits in the second mode,
The frame distribution unit inputs a data frame to one of the first and second communication units,
When changing the data frame transmission to the other wireless terminal from the one communication unit to the other communication unit, the channel or mode corresponding to the one communication unit is changed to the channel or mode corresponding to the other communication unit. A change notification for changing and a transmission start sequence number that is a sequence number to start transmission by the other communication unit is transmitted from the first communication unit or the second communication unit to the other wireless terminal, The one communication unit inputs at least an untransmitted data frame addressed to the other wireless terminal held in the one communication unit to the other communication unit, and the frame distribution unit includes the other wireless terminal. The distribution destination of the data frame addressed is switched from the one communication unit to the other communication unit, and the sequence number assigning means of the other communication unit The sequence number starting from the transmission start sequence number assigned to the other data frames of the wireless terminal addressed input to the communication unit,
The first communication unit includes the sequence number assigned to the data frame transmitted from the first communication unit and a delivery confirmation from the other wireless terminal for the data frame transmitted from the first communication unit. Based on the status of the reception sequence number described in the frame, manage the delivery status of the data frame transmitted from the first communication unit and perform retransmission grasp,
The second communication unit includes the sequence number assigned to the data frame transmitted from the second communication unit and a delivery confirmation from the other wireless terminal for the data frame transmitted from the second communication unit. A wireless terminal characterized by managing a delivery status of the data frame transmitted from the second communication unit based on a status of a reception sequence number described in a frame and grasping a retransmission. The first communication unit includes a first transmission queue that temporarily stores a data frame to which a sequence number is assigned by the first sequence number assigning unit,
The second communication unit includes a second transmission queue that temporarily stores a data frame to which a sequence number is assigned by the second sequence number assigning unit,
The first communication unit extracts and transmits the data frame to which the sequence number is assigned from the first transmission queue,
The second communication unit extracts and transmits the data frame to which the sequence number is assigned from the second transmission queue,
When changing the data frame transmission to the other wireless terminal from the one communication unit to the other communication unit, the one communication unit adds the untransmitted data frame to the other communication unit. Out of data frames that have been transmitted to the wireless terminal and have not yet been acknowledged for delivery, data frames that are less than the minimum sequence number of the untransmitted data frame and that continue from the minimum sequence number of the untransmitted data frame are included in the transmission queue. The wireless terminal according to claim 1, wherein the wireless terminal is extracted from the terminal and input to the other communication unit. The wireless terminal according to claim 1, wherein the change notification includes information on a channel or mode to be changed corresponding to the other communication unit. The wireless terminal according to claim 1, wherein the change notification includes information on a channel or mode of a change source corresponding to the one communication unit. A reordering buffer common to the first and second communication units;
The first communication unit receives the data frame assigned the sequence number from the other wireless terminal through the first channel or the first mode,
The second communication unit receives the data frame assigned the sequence number from the other wireless terminal via the second channel or the second mode,
The reordering buffer manages a minimum sequence number waiting for a data frame, stores the data frames received by the first and second communication units in order of sequence numbers, and stores data frames that match the minimum sequence number. Output and increment the minimum sequence number,
The first communication unit or the second communication unit receives the transmission start sequence number and the change notification transmitted from the other wireless terminal,
The reordering buffer outputs all internal data frames in response to reception of the change notification, and sets the minimum sequence number waiting for the data frame to the same value as the transmission start sequence number. The wireless terminal according to claim 1. The first communication unit includes a first reception status storage unit that stores a reception status of a data frame received from the other wireless terminal based on a sequence number of the data frame,
The second communication unit includes a second reception status storage unit that stores a reception status of a data frame received from the other wireless terminal based on a sequence number of the data frame,
When the change notification is received, the reception status storage unit of the communication unit corresponding to the change source channel or the change source mode specified based on the change notification is reset among the first and second communication units. The wireless terminal according to claim 5. The change notification from the other wireless terminal includes information on a channel or mode to be changed,
The radio terminal according to claim 6, wherein an exclusive channel or an exclusive mode of a channel or mode indicated in the change notification is determined as the change source channel or the change source mode. The change notification from the other wireless terminal includes information on the channel or mode of the change source,
The wireless terminal according to claim 6, wherein the channel or mode indicated in the change notification is determined as the change-source channel or mode. The first and second communication units respectively include first and second individual reordering buffers,
The first communication unit receives the data frame assigned the sequence number from the other wireless terminal through the first channel or the first mode,
The second communication unit receives the data frame assigned the sequence number from the other wireless terminal via the second channel or the second mode,
The first individual reordering buffer manages a minimum sequence number waiting for a data frame, stores the data frames received by the first communication unit in order of sequence numbers, and a data frame matching the minimum sequence number And increment the minimum sequence number,
The second individual reordering buffer manages a minimum sequence number waiting for a data frame, holds the data frames received by the second communication unit in order of sequence numbers, and a data frame that matches the minimum sequence number And increment the minimum sequence number,
The first communication unit or the second communication unit receives the transmission start sequence number and the change notification transmitted from the other wireless terminal,
The individual reordering buffer of the communication unit corresponding to the change source channel or the change source mode specified based on the change notification outputs all internal data frames,
The minimum sequence number waiting for the data frame in the individual reordering buffer of the communication unit corresponding to the change destination channel or change destination mode specified based on the change notification is set to the same value as the transmission start sequence number. The wireless terminal according to claim 1. A wireless terminal that communicates with other wireless terminals,
Sequence number giving means for giving a sequence number to a data frame to be transmitted to the other wireless terminal;
A frame distribution unit for performing a distribution process of the data frame to which the sequence number is assigned;
A first communication unit for transmitting the input data frame to the other wireless terminal in the first channel or the first mode;
A second communication unit that transmits the input data frame to the other wireless terminal in the second channel or the second mode, and
The frame distribution unit inputs a data frame to one of the first and second communication units,
When changing the data frame transmission to the other wireless terminal from the one communication unit to the other communication unit, the channel or mode corresponding to the one communication unit is changed to the channel or mode corresponding to the other communication unit. A change notification for changing and a transmission start sequence number that is a sequence number to start transmission by the other communication unit is transmitted from the first communication unit or the second communication unit to the other wireless terminal, A data frame addressed to the other wireless terminal held in the one communication unit and not confirmed for delivery is input to the other communication unit, and the frame distribution unit determines the distribution destination of the data frame Switch from the communication unit to the other communication unit,
The first communication unit includes the sequence number assigned to the data frame transmitted from the first communication unit and a delivery confirmation from the other wireless terminal for the data frame transmitted from the first communication unit. Based on the status of the reception sequence number described in the frame, manage the delivery status of the data frame transmitted from the first communication unit and perform retransmission grasp,
The second communication unit includes the sequence number assigned to the data frame transmitted from the second communication unit and a delivery confirmation from the other wireless terminal for the data frame transmitted from the second communication unit. Based on the status of the reception sequence number described in the frame, the delivery status of the data frame transmitted from the second communication unit is managed to perform retransmission grasp,
The wireless terminal characterized in that the minimum sequence number of the data frame addressed to the other wireless terminal input to the other communication unit is the transmission start sequence number. A reordering buffer common to the first and second communication units;
The first communication unit receives the data frame assigned the sequence number from the other wireless terminal through the first channel or the first mode,
The second communication unit receives the data frame assigned the sequence number from the other wireless terminal via the second channel or the second mode,
The reordering buffer manages a minimum sequence number waiting for a data frame, stores the data frames received by the first and second communication units in order of sequence numbers, and stores data frames that match the minimum sequence number. Output and increment the minimum sequence number,
The first communication unit or the second communication unit receives the transmission start sequence number and the change notification transmitted from the other wireless terminal,
The reordering buffer outputs all internal data frames in response to reception of the change notification, and sets the minimum sequence number waiting for the data frame to the same value as the transmission start sequence number. The wireless terminal according to claim 10. The first communication unit includes a first reception status storage unit that stores a reception status of a data frame received from the other wireless terminal based on a sequence number of the data frame,
The second communication unit includes a second reception status storage unit that stores a reception status of a data frame received from the other wireless terminal based on a sequence number of the data frame,
When the change notification is received, the reception status storage unit of the communication unit corresponding to the change source channel or the change source mode specified based on the change notification is reset among the first and second communication units. The wireless terminal according to claim 11. A reordering buffer common to the first and second communication units;
The first and second communication units respectively include first and second individual reordering buffers,
The first communication unit receives the data frame assigned the sequence number from the other wireless terminal through the first channel or the first mode,
The second communication unit receives the data frame assigned the sequence number from the other wireless terminal via the second channel or the second mode,
The first individual reordering buffer manages a minimum sequence number waiting for a data frame, holds frames received by the first communication unit in order of sequence numbers, and stores data frames that match the minimum sequence number. Pass to the common reordering buffer and increment the minimum sequence number;
The second individual reordering buffer manages a minimum sequence number waiting for a data frame, holds the data frames received by the second communication unit in order of sequence numbers, and the data that matches the minimum sequence number Passing the frame to the common reordering buffer and incrementing the minimum sequence number;
The common reordering buffer manages a minimum sequence number waiting for a data frame, holds the data frames passed from the first and second individual reordering buffers in order of sequence numbers, and matches the minimum sequence number Output the data frame and increment the minimum sequence number,
The first communication unit or the second communication unit receives the transmission start sequence number and the change notification transmitted from the other wireless terminal,
All the first data frames that are data frames having a sequence number equal to or greater than the transmission start sequence number in the individual reordering buffer of the communication unit corresponding to the channel or mode of the change source specified based on the change notification are all the common Pass it to the reordering buffer,
Set the minimum sequence number of the individual reordering buffer in the communication unit corresponding to the channel or mode of the change destination specified based on the change notification to the same value as the transmission start sequence number,
When the minimum sequence number of the common reordering buffer is updated due to the output of the first data frame from the common reordering buffer, the individual reordering of the communication unit corresponding to the channel or mode to be changed is performed. The wireless terminal according to claim 10, wherein the minimum sequence number of the ordering buffer is set to the same value as the updated minimum sequence number. The first and second communication units respectively include first and second individual reordering buffers,
The first communication unit receives the data frame assigned the sequence number from the other wireless terminal through the first channel or the first mode,
The second communication unit receives the data frame assigned the sequence number from the other wireless terminal via the second channel or the second mode,
The first individual reordering buffer manages a minimum sequence number waiting for a data frame, stores the data frames received by the first communication unit in order of sequence numbers, and a data frame matching the minimum sequence number And increment the minimum sequence number,
The second individual reordering buffer manages a minimum sequence number waiting for a data frame, holds the data frames received by the second communication unit in order of sequence numbers, and the data that matches the minimum sequence number Output a frame and increment the minimum sequence number;
The first communication unit or the second communication unit receives the transmission start sequence number and the change notification transmitted from the other wireless terminal,
The data channel larger than the transmission start sequence number from the individual reordering buffer of the communication unit corresponding to the change source channel or mode specified based on the change notification is changed to the change destination channel or mode specified based on the change notification Move to the individual reordering buffer of the communication unit corresponding to
The radio terminal according to claim 10, wherein the minimum sequence number of the dedicated reordering buffer corresponding to the channel or mode to be changed is set to the same value as the transmission start sequence number. The frequency band of the first channel or the first mode is 30 GHz or more and less than 300 GHz,
The radio terminal according to any one of claims 1 to 14, wherein the frequency band of the second channel or the second mode is 300 MHz or more and less than 30 GHz. The wireless terminal according to claim 15, wherein the change notification is transmitted in a second channel or a second mode. The wireless terminal according to any one of claims 1 to 10 , wherein the first channel and the second channel are different channels in the same frequency band.   A first antenna is provided, and both the first communication unit and the second communication unit communicate through the first antenna.
  The wireless terminal according to claim 17. A first antenna;
A second antenna,
The first communication unit communicates with the other wireless terminal via the first antenna,
The wireless terminal according to any one of claims 1 to 10 , wherein the second communication unit communicates with the other wireless terminal via the second antenna. A wireless communication method for performing wireless communication with another wireless terminal using a first communication unit that performs communication in the first channel or the first mode and a second communication unit that performs communication in the second channel or the second mode Because
A frame distribution step of inputting a data frame to be transmitted to the other wireless terminal to one of the first and second communication units;
A first transmission step of assigning a sequence number to the data frame input to the first communication unit and transmitting the data frame to the other wireless terminal in the first channel or the first mode;
A second transmission step of assigning a sequence number to the data frame input to the second communication unit and transmitting the data frame to the other radio terminal in the second channel or the second mode;
When changing the data frame transmission to the other wireless terminal from the one communication unit to the other communication unit, the channel or mode corresponding to the one communication unit is changed to the channel or mode corresponding to the other communication unit. A change notification to change and a transmission start sequence number that is a sequence number to start transmission by the other communication unit is transmitted from the first communication unit or the second communication unit to the other wireless terminal A notification step;
When changing the data frame transmission to the other wireless terminal from the one communication unit to the other communication unit, at least an untransmitted data frame addressed to the other wireless terminal held in the one communication unit A frame moving step to be input to the other communication unit;
A switching step of switching the data frame distribution destination from the one communication unit to the other communication unit when changing the data frame transmission to the other wireless terminal from the one communication unit to the other communication unit; ,
When changing the data frame transmission to the other wireless terminal from the one communication unit to the other communication unit, the transmission start sequence is added to the data frame addressed to the other wireless terminal input to the other communication unit. A communication unit change corresponding sequence giving step for assigning a sequence number starting from a number;
The sequence number assigned to the data frame transmitted from the first communication unit and the reception sequence number described in the delivery confirmation frame from the other wireless terminal for the data frame transmitted from the first communication unit Managing the delivery status of the data frame transmitted from the first communication unit based on the status of
The sequence number assigned to the data frame transmitted from the second communication unit, and the reception sequence number described in the delivery confirmation frame from the other wireless terminal for the data frame transmitted from the second communication unit Managing the delivery status of the data frame transmitted from the second communication unit based on the status of
A wireless communication method comprising:   A wireless communication method for performing wireless communication with another wireless terminal using a first communication unit that performs communication in the first channel or the first mode and a second communication unit that performs communication in the second channel or the second mode Because
  A sequence number giving step for assigning a sequence number to a data frame to be transmitted to the other wireless terminal;
  A frame distribution step of inputting the data frame to which the sequence number is assigned to one of the first and second communication units;
  A first transmission step of transmitting the data frame input to the first communication unit to the other wireless terminal in the first channel or the first mode;
  A second transmission step of transmitting the data frame input to the second communication unit to the other wireless terminal in the second channel or the second mode;
  When changing the data frame transmission to the other wireless terminal from the one communication unit to the other communication unit, the channel or mode corresponding to the one communication unit is changed to the channel or mode corresponding to the other communication unit. A change notification to change and a transmission start sequence number that is a sequence number to start transmission by the other communication unit is transmitted from the first communication unit or the second communication unit to the other wireless terminal A notification step;
When changing the data frame transmission to the other wireless terminal from the one communication unit to the other communication unit, the data frame that has not been acknowledged for delivery to the other wireless terminal held in the one communication unit And switching the data frame distribution destination from the one communication unit to the other communication unit;
  The sequence number assigned to the data frame transmitted from the first communication unit and the reception sequence number described in the delivery confirmation frame from the other wireless terminal for the data frame transmitted from the first communication unit Managing the delivery status of the data frame transmitted from the first communication unit based on the status of
  The sequence number assigned to the data frame transmitted from the second communication unit, and the reception sequence number described in the delivery confirmation frame from the other wireless terminal for the data frame transmitted from the second communication unit Managing the delivery status of the data frame transmitted from the second communication unit based on the status of
  Setting the minimum sequence number of the data frame addressed to the other wireless terminal input to the other communication unit as the transmission start sequence number;
  A wireless communication method comprising:

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