JP4343220B2 - COMMUNICATION DEVICE, COMMUNICATION METHOD, COMMUNICATION PROGRAM, AND RECORDING MEDIUM CONTAINING COMMUNICATION PROGRAM - Google Patents

Description

  The present invention relates to a communication apparatus and a communication method for performing packet communication by radio, for example.

(OSI architecture)
In recent years, the usage forms of information communication networks have been diversified more and more widely. As a result, computer systems having different network architectures need to be interconnected. In order to enable such heterogeneous communication, a standard network architecture called OSI (Open Systems Interconnection) has been proposed.

  The OSI reference model consists of (1) physical layer, (2) data link layer, (3) network layer, (4) transport layer, (5) session layer, (6) presentation layer, (7) application layer, It consists of seven layers.

  (1) The physical layer is a layer that manages the electrical, mechanical, and physical conditions and guarantees bit string transmission because a physical medium such as a telephone line or a coaxial cable is used as a communication line. (2) The data link layer guarantees that a frame composed of bit strings is reliably transmitted to the partner system by detecting and recovering bit errors that occur on the transmission path between adjacent communicating systems. It is a layer to do. The data link layer includes, for example, LLC (Logical Link Control) and MAC (Media Access Control).

  (3) The network layer uses various communication networks, manages the relay and routing functions for establishing a communication path with the end-end system that is the communication partner, and guarantees data transmission between the end-end systems. Is a layer. (4) The transport layer is a layer that ensures that data is reliably transferred between processes that are actually communicating in the last system on both sides of the communication network. (5) The session layer is a layer that manages information required by the process (for example, half-duplex or full-duplex management, transmission right management, etc.), synchronization between processes, and resynchronization management. .

  (6) The presentation layer determines the data structure (syntax) to be transferred between processes, and performs conversion between the data structure unique to each process and the common data structure required for transfer as necessary. . (7) The application layer is the highest layer and provides a user with file transfer, e-mail, network management, and the like.

  In the OSI reference model as described above, when data is transmitted, data flows from the seventh layer to the first layer, whereas when data is received, data flows from the first layer to the seventh layer. Become.

(Multilink & MIMO)
On the other hand, in recent years, the demand for transmission of a larger amount of data in a communication network has increased, and the demand for speeding up communication has increased remarkably. Here, as a method of increasing the transmission speed of data communication, a method of increasing the transmission speed of the physical layer can be mentioned. However, the transmission rate of the physical layer has a limit corresponding to the characteristics of the communication medium and protocol. For example, the physical speed of ISDN (integrated services digital network) is 64 Kbps, and the maximum speed of a wireless LAN according to IEEE802.11a is 54 Mbps. is there.

  On the other hand, as another method for increasing the transmission rate of data communication, a multilink protocol (see documents such as US Pat. No. 6,614,808 (Date of Patent: Sep. 2, 2003), PPP MultiLink Protocol (RFC 1990, 1996/8)). And MIMO (Multiple Input Multiple Output) (PW Wolyansky, GJ Foschini, GD Golden, RA Valenzuela: “V-Blast: An Architecture for Rheating V Rheet Rheet Rheet e Rhe te V i R e s e V i n e r e r e i n e r i n e r i i n e n i n e r i i i i i i i i i i. Scattering Wireless Channel ", Proc. ISSSE-98, Pisa, Italy, Sep. 29, There is a reference), such as 998. The multilink protocol is generally realized as a function of the data link layer. According to the multi-link protocol, a process is performed in which a plurality of specific data links are aggregated at the uppermost portion of the data link layer and shown as a single virtual data link to an upper layer (network layer). . According to such processing, the transmission rate of the virtual data link is the sum of the rates of the individual data links.

  In the current multilink protocol, when an error occurs in a packet transferred in a data link, the packet in which the error occurs is retransmitted in the same data link according to the procedure of the MAC sublayer of the data link layer. Is called.

  While multilink can be used by wire and wireless, MIMO is a wireless physical layer technology. The name of MIMO is derived from the fact that there are a plurality of signals input / output to / from a transmission line using the same frequency band. In the system example shown in FIG. 35, the MIMO transmitter 51 has N antennas, and the MIMO receiver 52 has M antennas. Then, Tx1 to Tx2 signals transmitted from the respective antennas in the MIMO transmitter 51 are received as Rx1 to Rx2 signals in the respective antennas in the MIMO receiver 52. As the types of MIMO, there are MIMO spatial diversity and MIMO spatial multiplexing (SM). In the following description, the MIMO SM is targeted.

  FIG. 36A shows a transmission form using a conventional single link. Conventionally, only one signal is transmitted for one frequency band. In the example shown in the figure, the symbol A is first input to the transmitter 61, and the transmitter 61 modulates the input signal A into a signal Tx and wirelessly outputs it to the transmission path h. The signal Tx passes through the transmission path h and then is input to the receiver 62 as Rx. The receiver 62 outputs the signal A by demodulating the signal Rx. Here, the signal Rx can be expressed by an equation of Rx = Tx * h + (noise component). That is, when the signal Tx is the frequency spectrum shown in the left graph of FIG. 36B, the signal Rx received by the receiver 62 is like the frequency spectrum shown in the right graph of FIG. The transmission line h is affected by the transmission coefficient h and the noise component.

FIG. 36C shows a transmission form by MIMO when the number of transmission antennas and the number of reception antennas are two. In the example shown in the figure, two signals A and B are simultaneously input to the MIMO transmitter 51, and the MIMO transmitter 51 modulates the input signals A and B into signals Tx1 and Tx2 by the modulators 51a and 51b, respectively. And output wirelessly. The signals Tx1 and Tx2 are input to the MIMO receiver 52 as the signals Rx1 and Rx2 after passing through the transmission path H. Here, the signals Rx1 and Rx2 are expressed by the following equations.
Rx1 = Tx1 * h11 + Tx2 * h12 + (noise component)
Rx2 = Tx1 * h21 + Tx2 * h22 + (noise component)
As in the above equation, the signal of each receiving antenna includes both Tx1 and Tx2 components.

  The signals Rx1 and Rx2 received by the MIMO receiver 52 are converted into signals Tx1A and Tx2A by an ICI (Inter-Channel Interference) Canceller. Tx1A · Tx2A corresponds to a BB (Base Band) signal of Tx1 · Tx2. Thereafter, the signals Tx1A and Tx2A are demodulated into signals A and B by the demodulation units 52a and 52b, respectively, and output.

  As described above, in the past, only one signal (A) could be transmitted / received at the same time. On the other hand, when MIMO is used, two signals (A, B) can be transmitted on the same channel by using two transmitting and receiving antennas. Transmission can be performed simultaneously, and high speed can be achieved.

  FIG. 47 shows a case where one signal BA is transmitted and received in MIMO with two transmission antennas and two reception antennas. A signal BA input to the MIMO transmitter 51 is divided into a signal A and a signal B in an S / P (Serial / Parallel) 51c and transmitted to the MIMO receiver 52 through different antennas. In the MIMO receiver 52, the received and demodulated signal A and signal B are combined by the P / S 52d, and the signal BA is output. In this example, the transmission speed is increased by transmitting one signal simultaneously with a plurality of antennas.

  Note that the disadvantage of speeding up using a plurality of channels is that the band to be used increases and the number of users who can join is reduced. On the other hand, a disadvantage of MIMO is that the communication distance is shortened because the signals of the respective antennas influence each other.

(QoS image data)
In recent years, the demand for streaming large amounts of moving image data and the like has also increased. When transmitting such streaming data, real-time performance is required for communication. In other words, the packet (QoS packet) constituting the streaming data has an expiration date, and must be transmitted within the expiration date.

  FIG. 37 shows a schematic diagram of a packet sequence of an example in which transmission of a QoS packet is successful and an example in which transmission is unsuccessful. In the successful case, the packet 5 has failed to be transmitted when it is first transmitted, and has been successfully transmitted when it is retransmitted. Since the time of this retransmission is before the expiration date of the packet 5, the transmission of the packet 5 is successful.

  On the other hand, in the failure case, the packet 5 has failed to be transmitted when transmitted for the first time and at the first retransmission. Thereafter, the expiration date after the packet has passed before the second retransmission. In this case, the QoS packet 5 that could not be transmitted within the expiration date cannot be used and becomes invalid (packet loss), and the video based on the moving image data is disturbed on the receiving side. That is, when performing retransmission to compensate for transmission errors, it is important that retransmission be successful within the validity period of each packet.

  IEEE 802.11e (see documents such as IEEE Std 802.11e Draft7 (2004/1)) specialized for QoS data communication in a wireless LAN is designed to realize retransmission of QoS packets within such an expiration date. MAC layer protocol. In IEEE 802.11e, two methods for confirming whether or not a packet has been transmitted normally have been proposed. The first method is a method in which the communication device on the reception side transmits a reception confirmation packet (Normal Ack: hereinafter referred to as ACK) to the transmission side for each received QoS packet. As a second method, the communication device on the transmission side transmits a plurality of QoS packets in bursts, and then transmits a delivery confirmation request packet (BAR: Block Ack Request) for the transmitted QoS packet, and communication on the reception side. This is a method in which the device returns a reception confirmation packet (BA: Block Ack) for the received QoS packet in accordance with the BAR.

  Here, since it is necessary to arrange the order of the packets on the receiving side, the QoS packets are given an order number in advance. In the method using ACK, which is the first method, the specification is such that QoS packets are transmitted in order. On the other hand, in the case of the method using BAR / BA, which is the second method, SequenceControl indicating the sequence number of the first packet of the QoS packet to be confirmed for delivery is indicated in BAR, and SequenceControl is indicated in BA. The reception confirmation information regarding a total of 64 QoS packets from the QoS packet with the sequence number shown to the QoS packet with the sequence number shown with SequenceControl + 63 is shown.

  Note that burst communication using BAR / BA can be used not only for QoS packets but also for normal data packets with no expiration date.

(Packet Aggregation)
An example of transmission when ACK is used is shown in FIG. As shown in the figure, a transmission packet including data to be transmitted includes a preamble & header, actual data, and an error check code E. The ACK for such a transmission packet is transmitted after SIFS (Short Inter Frame Space) after the transmission of the transmission packet is completed. Then, another packet can be transmitted after SIFS after transmission of ACK is completed.

  Here, if the period required for transmitting the preamble & header part is TP, the period required for transmitting the actual data part is TDATA, and the period required for transmitting the ACK is TACK, the actual data transmission is performed. Of the total communication period required for the period, a period (non-actual data transmission period) other than the period required for transmitting the actual data portion is TP + 2 * SIFS + TACK. That is, it can be seen that the smaller the size of the actual data, the larger the proportion of the non-actual data transmission period in the total communication period.

  Here, it is conceivable to use a technique called Packet Aggregation for the purpose of reducing the non-real data transmission period. Packet aggregation is a technique in which a plurality of packets are combined into one aggregate packet and the aggregate packet is transmitted in the physical layer. By such a method, the ratio of the non-actual data transmission period to the total communication period can be reduced.

  FIG. 39A and FIG. 39B show an example of a packet sequence of a transmission packet using packet aggregation. As shown in the figure, an aggregate packet including three packets 1, 2, and 3 in the actual data portion is transmitted as a transmission packet. In the figure, H1, H2, and H3 indicate the headers of packet 1, packet 2, and packet 3, respectively. These headers may be provided at the beginning of each packet, as shown in FIG. 11A, or collectively provided at the beginning of the actual data portion of the aggregate packet, as shown in FIG. May be.

  Further, when using Packet Aggregation, the destinations of the packets need not all be the same communication station. For example, in the case of the above example, packet 1 can be transmitted to communication station A, and packets 2 and 3 can be transmitted to communication station B. Here, the destination information of each packet may be stored in the header (H1, H2, H3) corresponding to each packet.

The packet aggregation processing may be performed in a layer above the MAC layer, but in the following description, packet aggregation is performed in the MAC layer. FIG. 40 shows a transmission frame (packet) processed in the MAC layer of IEEE 802.11. The data packet is input with the name of MSDU (MAC Service Data Unit), and the MAC layer adds a MAC header and CRC to this to generate a frame called MPDU (MAC Protocol Data Unit). When Packet Aggregation is adapted to IEEE802.11, aggregate packets as shown in FIGS. 41A and 41B are generated. As shown in the figure, packet 1, packet 2 and packet 3 shown in FIGS. 39A and 39B correspond to MSDU1, MSDU2 and MSDU3, respectively, and the actual data portion of the aggregate packet corresponds to MPDU. Become.
(Problem 1)
When Packet Aggregation is used, ACK can be set in MPDU units as in the conventional IEEE 802.11. In this case, a CRC (Cyclic Redundancy Code) error check code is applied to the entire MPDU. Then, as shown in FIG. 42, when one MSDU becomes an error, the entire MPDU becomes an error, and other MSDUs that are normally received are also treated as errors. Therefore, the transmission efficiency is reduced.
(Problem 2)
When each MSDU included in one MPDU is communicated to another communication station using Packet Aggregation, there arises a problem of when an ACK is received from the communication station that has transmitted the MSDU. If all communication stations return ACK at the same time, an ACK collision problem occurs as shown in FIG. In the case of FIG. 43, the communication station 1 simultaneously sends MPDUs to the communication station 2 and the communication station 3, MSDU 1 in the MPDU is sent to the communication station 2, and MSDU 2 is sent to the communication station 3. In this case, it is necessary for the communication station 2 and the communication station 3 to return an ACK to the communication station 1, and if they return at the same time, an ACK collision occurs.

Here, as shown in FIG. 44 (a), the communication station 3 can recognize ACK1 of the communication station 2 and return the ACK2 after the ACK1 is completed. In this case, FIG. 44 (b) ) Causes hidden terminal problems. In this case, the communication station 1 that expects ACK1 can recognize ACK1, but the communication station 3 is in a communicable range with the communication station 1, but is out of the communicable range with the communication station 2, so the ACK1 Cannot be recognized and ACK2 cannot be returned.
(Problem 3)
Packet aggregation can also be used for burst transfer. In this case, BAR / BA can be made to correspond to all MSDUs similarly to ACK. However, in this case, the number of packets to be confirmed increases because confirmation is performed in units of MSDUs. In the conventional 802.11e BAR / BA, only 64 ranges of MSDUs can be confirmed at a time, so it is necessary to improve the method for confirming the BAR / BA.

Also, there is a problem of time for confirming MSDU transmitted for each destination as in the case of ACK.
(Problem 4)
When a plurality of MSDUs are transmitted by MIMO, each MSDU is transmitted by each transmission antenna of MIMO. However, there is information common to MSDUs, and a problem remains as to which antenna transmits this common information.
(Problem 5)
When performing data transfer using MIMO, it is necessary to transmit data simultaneously using all the transmission antennas. Also, the communication status of each antenna is not the same. For this reason, data transmission is performed by adjusting the optimum transmission rate for each antenna. In the case of 802.11a / 11e, the transmission rate of the physical layer is 6, 9, 12, 24, 36, 48, and 54 MBps. Therefore, as shown in FIG. 45, the time during which data is transmitted by each antenna is the same, but since the transmission speed is different, the amount of data transmitted by each antenna is different. FIG. 45 shows that when 1000 bytes are transmitted at a transmission rate of 24 MBps, 1500 bytes can be transmitted at 36 MBps in the same transmission time.

  However, since the length of the MSDU input to the MAC is already determined, it is not possible to match all packets to the transmission time of each antenna. Here, as shown in FIG. 46, the transmission time of the MPDU can be adjusted to the transmission time of the longest antenna, but the band is wasted with the antenna having a shorter transmission time. Although the transmission speed of the antenna that ends earlier can be reduced, in this case, the band is wasted because the optimum transmission speed is not used.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a communication apparatus and a communication method for solving problems that occur when performing packet transmission.

  More specifically, the first object of the present invention is to combine the plurality of packets to be transmitted into one aggregate packet, and when the aggregate packet is transmitted to the receiving device, the size of the aggregate packet. It is an object of the present invention to provide a communication device and a communication method that improve transmission efficiency by reducing the size of the communication device.

  In addition, a second object of the present invention is to combine a plurality of packets to be transmitted into one aggregate packet and transmit the packet included in the aggregate packet when the aggregate packet is transmitted to a receiving device. It is an object of the present invention to provide a communication apparatus and a communication method that improve transmission efficiency by not affecting other packets even when an error occurs.

  Further, the third object of the present invention is to prevent a situation such as collision of transmission of delivery confirmation from each communication device when, for example, transmission packets are simultaneously sent to a plurality of communication devices. A communication device and a communication method are provided.

  In addition, a fourth object of the present invention is to collect a plurality of packets to be transmitted into one aggregate packet, and when the aggregate packet is transmitted to the receiving device, more packets to be acknowledged are sent. An object of the present invention is to provide a communication apparatus and a communication method capable of generating a delivery confirmation request packet that can be included.

  The fifth object of the present invention is to increase the degree of freedom of the configuration of the aggregate packet when a plurality of packets to be transmitted are combined into one aggregate packet and the aggregate packet is transmitted to the receiving device. Accordingly, it is an object of the present invention to provide a communication device and a communication method that can set the size of the aggregate packet to a size according to the state.

The communication device according to the present invention is a communication device that communicates with a receiving device in a communication network, and includes a collective packet generating unit that performs processing to combine a plurality of packets to be transmitted into one collective packet, and the collective packet generation Communication means for transmitting the aggregate packet generated by the means to the receiving apparatus, wherein the aggregate packet generator performs error check processing for each of the one or more packets to be transmitted It is characterized by having.

The communication method according to the present invention is a communication method in a communication device that communicates with a receiving device in a communication network, and includes a collective packet generation process that performs a process of combining a plurality of packets to be transmitted into one collective packet. A communication process for transmitting the aggregate packet generated by the aggregate packet generation means to the receiving device, wherein the aggregate packet generation process performs an error check process for each of the one or more packets to be transmitted. It is characterized by including error checking processing to be performed.

According to the above configuration and method, a plurality of packets to be transmitted are combined into one aggregate packet, and the aggregate packet is transmitted to the receiving device. Further, when generating the aggregate packet, an error check process is performed for each packet. Conventionally, for an aggregate packet, an error check process is performed on the entire aggregate packet. In this case, if an error occurs in one of the packets included in the aggregate packet, the other packets included in the aggregate packet also become an error, resulting in poor transmission efficiency. On the other hand, according to the above configuration and method, error check processing is performed for each of one or more packets included in the aggregate packet, so that an error occurs in one of the packets included in the aggregate packet. However, the remaining packets can be transmitted normally. Therefore, there is an effect that transmission efficiency can be improved.

  The communication device according to the present invention may be configured such that, in the above configuration, the error check processing means also performs error check processing on the header of the aggregate packet.

  The header of the aggregate packet may be configured to include information regarding the packets included in the aggregate packet. Here, when an error check process is performed for each packet, information regarding each packet is important when a delivery confirmation or the like is returned. On the other hand, according to the above configuration, since the error check process is also performed on the header of the aggregate packet, the reliability of the information indicated in the header can be improved. Therefore, even when error check processing is performed for each packet, there is an effect that transmission with high reliability can be performed.

  Further, the communication apparatus according to the present invention, in the above configuration, has a delivery confirmation request means for generating a delivery confirmation request packet for requesting the reception apparatus to return delivery confirmation information for each packet included in the aggregate packet. And the communication means transmits the delivery confirmation request packet to the receiving apparatus when it cannot normally receive the delivery confirmation packet for the aggregate packet from the receiving apparatus at a timing to be received. It is good also as a structure.

  When transmission is performed using an aggregate packet, a communication scheme in which a delivery confirmation packet for the aggregate packet is transmitted from the receiving side can be considered. Here, when the delivery confirmation packet for the aggregate packet cannot be normally received at the timing at which it should be received from the reception device, the transmission side determines which packet included in the aggregate packet has failed to be received. I can't figure it out. Therefore, in this case, it is necessary to retransmit the entire aggregate packet.

  On the other hand, according to the above configuration, when the delivery confirmation packet for the aggregate packet cannot be normally received at the timing when it should be received from the receiving device, the delivery to each packet included in the aggregate packet is performed. A delivery confirmation request packet for requesting return of confirmation information is transmitted. As a result, a delivery confirmation packet indicating which packet included in the aggregate packet has failed to be received can be received from the receiving side. Based on this, a new aggregate packet including a packet to be retransmitted is generated. You can send it again. Therefore, the number of packets to be retransmitted can be reduced, and the communication band utilization efficiency can be improved.

  The communication means further comprises a delivery confirmation requesting means for generating a delivery confirmation request packet for requesting the receiving side of the packet to transmit a delivery confirmation packet for each of the packets included in the aggregate packet. When the communication unit receives a delivery confirmation packet for the aggregate packet from the receiving device in an error state, delivery to each of the packets included in the aggregate packet generated by the delivery confirmation request unit The confirmation request packet may be transmitted to the external communication device.

  The communication apparatus according to the present invention may be configured such that the delivery confirmation request packet further includes identification information of a packet included in the aggregate packet in the above configuration.

  Thereby, for example, it is possible to set the content of the packet to be acknowledged by the delivery confirmation request packet to be different from the content of the packet transmitted by the aggregate packet.

  In the communication device according to the present invention, in the above configuration, the aggregate packet generation unit adds an aggregate packet number for identifying each aggregate packet to each aggregate packet, and generates the delivery confirmation request packet. The means may include the aggregate packet number for the delivery confirmation request packet.

  Accordingly, as compared with the case where the identification information of all the packets is included in the delivery confirmation request packet, it is only necessary to include the aggregate packet number information, so that the delivery confirmation request packet can be shortened.

  A communication apparatus according to the present invention is a communication apparatus that communicates with a receiving apparatus in a communication network, and includes a collective packet generating unit that performs a process of combining a plurality of packets to be transmitted into one collective packet, and the collective packet A delivery confirmation requesting means for generating a delivery confirmation request packet for requesting a reception side of the packet to transmit a delivery confirmation packet for each of the included packets, and an aggregate packet generated by the aggregate packet generation means, And a communication unit that transmits the delivery confirmation request packet generated by the delivery confirmation request means to the reception device, and the delivery confirmation request packet includes information for specifying a packet that is a target for requesting delivery confirmation. It is characterized by including.

  The communication method according to the present invention is a communication method in a communication device that communicates with a receiving device in a communication network, and includes a collective packet generation process that performs a process of combining a plurality of packets to be transmitted into one collective packet. , Generated by a delivery confirmation request process for generating a delivery confirmation request packet for requesting a reception side of the packet to transmit a delivery confirmation packet for each of the packets included in the aggregate packet, and the aggregate packet generation process And a communication process for transmitting the delivery confirmation request packet generated by the delivery confirmation request process to the receiving device, and the delivery confirmation request packet is a packet for which a delivery confirmation is requested. It contains information that identifies

  According to the above configuration and method, a plurality of packets to be transmitted are combined into one aggregate packet, and the aggregate packet is transmitted to the receiving device. In addition, a delivery confirmation request packet for a packet included in the aggregate packet is transmitted to the receiving device. Here, when delivery confirmation is performed for each packet included in the aggregate packet, it is conceivable that the number of packets to be delivery confirmed increases. Here, in the conventional 802.11e BAR / BA, since only 64 ranges of MSDUs can be confirmed at a time, it is necessary to be able to handle more packets.

  On the other hand, according to the above configuration and method, since the delivery confirmation request packet includes information for identifying a packet that is a target for requesting delivery confirmation, it is only necessary to add information for identifying the packet. There is an effect that it is possible to increase the number of packets to be confirmed for delivery. Note that there is a limitation on the number of packets that represent the number of packets in the number of packets that are one delivery confirmation target. For example, when the information for the number of packets in the information specifying the packet is 16 bits, the limit on the number of packets is 2 ^ 16-1 = 65535.

  The communication apparatus according to the present invention is a communication apparatus that receives an aggregate packet from the communication apparatus, wherein the aggregate packet or a reception status of the packet is detected, and a detection result by the reception status detection means In accordance with the present invention, the aggregate packet or the bitmap corresponding to the packet is generated, a delivery confirmation generating means for generating a delivery confirmation packet including the bitmap, and a communication unit for transmitting the delivery confirmation packet is provided. As a result, it is possible to cope with the receiving device of the communication device.

  The communication device according to the present invention is a communication device that communicates with a receiving device in a communication network, and includes a collective packet generating unit that performs processing to combine a plurality of packets to be transmitted into one collective packet, and the collective packet generation A communication unit that transmits the aggregate packet generated by the means to the receiving device, wherein the aggregate packet generation means extracts common information common to all of the plurality of packets to be transmitted included in the aggregate packet A common information extracting means; and a common packet extracting means for generating the collective packet after including the common information in the collective packet and deleting the common information from at least one of the packets to be transmitted. It is characterized by having.

  The communication method according to the present invention is a communication method in a communication device that communicates with a receiving device in a communication network, and includes a collective packet generation process that performs a process of combining a plurality of packets to be transmitted into one collective packet. A communication process for transmitting the aggregate packet generated by the aggregate packet generation process to the receiving apparatus, and the aggregate packet generator process is common to all of the plurality of packets to be transmitted included in the aggregate packet A common information extraction process for extracting common information, and a set for generating the aggregate packet after including the common information in the aggregate packet and deleting the common information from at least one of the packets to be transmitted It includes a packet reconstruction process.

  According to the above configuration and method, a plurality of packets to be transmitted are combined into one aggregate packet, and the aggregate packet is transmitted to the receiving device. Further, when generating the aggregate packet, the following processing is performed. That is, first, common information common to all the plurality of packets included in the aggregate packet is extracted, and the common information is combined into one in the aggregate packet. Therefore, the size of the aggregate packet can be further reduced as compared to a case where a plurality of packets are simply combined into an aggregate packet. As a result, the packet transmission efficiency can be improved.

  Moreover, the communication device according to the present invention may be configured such that, in the above configuration, the common information extraction unit uses the common information as at least a part of information in headers of the plurality of packets to be transmitted. Since the packet header often contains information common to a plurality of packets, this configuration has an effect that the common information can be efficiently extracted.

  In the communication device according to the present invention, in the above configuration, the common information extraction unit transmits the common information when the plurality of packets to be transmitted included in the aggregate packet are all of the same type. The entire header of the power packet may be configured.

  When a plurality of packets included in the aggregate packet are all the same type, the header of each packet is often common. Therefore, according to the above configuration, all the headers of the respective packets are shared, so that the ratio of the actual data portion in the aggregate packet can be further increased.

  In the communication apparatus according to the present invention, the common information extraction unit does not extract the common information when there are a plurality of types of the plurality of packets to be transmitted included in the aggregate packet. Also good.

  When there are a plurality of types of packets included in the aggregate packet, there is often no information common to all packets. Therefore, according to the above configuration, the extraction process can be omitted by not extracting the common information when there are a plurality of types of packets. Therefore, there is an effect that the processing can be speeded up.

  A communication apparatus according to the present invention is a communication apparatus that communicates with a reception apparatus in a communication network, and generates a transmission packet, and a transmission packet generated by the packet generation means to the reception apparatus. A communication unit for transmitting, and the packet generating means includes a reply time calculating means for calculating a reply time of a delivery confirmation packet by the receiving side with respect to the generated transmission packet, and the packet generating means stores the information on the reply time. It is included in the transmission packet.

  The communication method according to the present invention is a communication method in a communication device that communicates with a receiving device in a communication network, the packet generation processing for generating a transmission packet, and the transmission packet generated by the packet generation means Communication processing to be transmitted to the receiving device, and the packet generation processing includes a reply time calculation processing for calculating a reply time of a delivery confirmation packet by the reception side with respect to the transmission packet to be generated. It is included in the transmission packet.

  According to the configuration and method described above, the return time of the delivery confirmation packet by the reception side with respect to the transmission packet is calculated, and information on the return time is included in the transmission packet. Therefore, for example, when transmission packets are sent to a plurality of communication devices at the same time, it is possible to prevent a situation in which transmission of delivery confirmation from each communication device collides.

  A communication apparatus according to the present invention is a communication apparatus that receives a transmission packet from the communication apparatus, and includes a reception state detection unit that detects a reception state of the transmission packet, and a reply time included in the transmission packet. A reply time extracting means for extracting information, a delivery confirmation generating means for generating a delivery confirmation packet for the transmission packet according to a detection result by the reception state detecting means, and a communication unit for sending the delivery confirmation packet at the reply time It is possible to cope with the above communication device.

  In the communication apparatus according to the present invention, in the above configuration, the packet generation unit includes a reply time flag indicating whether or not the transmission packet includes reply time information in a header of the transmission packet to be generated. It is good also as a structure to include.

  In the case of this configuration, there is an effect that the communication device on the receiving side can confirm whether or not the reply time information is included by confirming the header of the received transmission packet.

  Further, in the communication apparatus according to the present invention, in the above configuration, the packet generation unit generates a collective packet in which a plurality of packets are combined into one as the transmission packet, and the reply time calculation unit includes the The reply time for each packet included in the aggregate packet may be calculated.

  According to this configuration, since a reply time is set for each packet included in the aggregate packet, for example, even when the destination of each packet is a different communication device, the timing at which each communication device transmits a delivery confirmation There is an effect that it becomes possible to accurately recognize.

  The communication device according to the present invention is a communication device that communicates with a receiving device in a communication network, and includes a collective packet generating unit that performs processing to combine a plurality of packets to be transmitted into one collective packet, And a communication unit that transmits the aggregate packet generated by the means to the receiving device, wherein the aggregate packet generator divides at least one of the plurality of packets to be transmitted into a plurality of packets. Each divided packet is assigned to a plurality of aggregate packets.

  The communication method according to the present invention is a communication method in a communication device that communicates with a receiving device in a communication network, and includes a collective packet generation process that performs a process of combining a plurality of packets to be transmitted into one collective packet. A communication process for transmitting the aggregate packet generated by the aggregate packet generation process to the receiving device, wherein the aggregate packet generation process includes at least one packet among a plurality of packets to be transmitted. It is characterized by dividing and assigning each divided divided packet to a plurality of aggregate packets.

  According to the above configuration and method, the packet to be included in the aggregate packet is divided into a plurality of packets, and each divided packet is allocated to a plurality of aggregate packets. Therefore, since the degree of freedom of the configuration of the aggregate packet can be increased, there is an effect that it is possible to appropriately cope with a case where the size of the aggregate packet needs to be adjusted for some reason.

  Further, the communication device according to the present invention has a configuration in which, in the above configuration, the communication unit includes a plurality of transmission antennas, and a plurality of aggregate packets generated by the aggregate packet generation unit are distributed to each transmission antenna and transmitted. Also good.

  As described above, when data is transferred using MIMO, it is necessary to transmit data simultaneously using all the transmission antennas. In this case, the transmission time of a packet transmitted from each transmission antenna varies due to a difference in transmission speed between the transmission antennas and a difference in size of a packet transmitted in each transmission antenna. That is, there is a problem that a band is wasted with an antenna having a shorter transmission time.

  On the other hand, according to the above configuration, the aggregate packet is divided so that the packets included in the aggregate packet are divided and allocated to different aggregate packets so that the length of the aggregate packet transmitted by each transmission antenna is approximately equal. Can be generated. Therefore, it is possible to align the transmission time of one collective packet by each transmission antenna, and it is possible to improve the band utilization efficiency.

  Moreover, the communication apparatus according to the present invention may be configured such that, in the above-described configuration, the aggregate packet including each divided packet divided from one packet is transmitted from the same transmission antenna.

  When the packet is divided and transmitted as in the above configuration, by transmitting the divided packet through the same antenna, only one of the divided packets fails to be transmitted, and thus the divided packet that has been successfully transmitted is wasted. The occurrence of the situation can be suppressed. Therefore, there is an effect that the band utilization efficiency can be improved.

  The communication apparatus according to the present invention further comprises a delivery confirmation requesting means for generating a delivery confirmation request packet for requesting a return of the delivery confirmation packet for the aggregate packet to the receiving side of the packet in the above configuration. Further, the communication unit may further transmit the delivery confirmation request packet to the receiving device. That is, in the case of this configuration, when a packet is divided and transmitted, it is possible to send a delivery confirmation request packet for requesting a return of the delivery confirmation packet for the aggregate packet to the receiving side of the packet. .

  Further, the communication device according to the present invention generates a delivery confirmation request packet for requesting the reception side of the packet to return a delivery confirmation packet for each of the packets included in the aggregate packet in the above configuration. It is good also as a structure further provided with the delivery confirmation request | requirement means to perform, and the said communication part further transmits the said delivery confirmation request packet with respect to the said receiving device. That is, in the case of this configuration, when a packet is divided and transmitted, a delivery confirmation request packet for requesting a reply of the delivery confirmation packet to each of the packets included in the aggregate packet is sent to the receiving side of the packet. It becomes possible to send.

  The communication apparatus according to the present invention further comprises a delivery confirmation requesting means for generating a delivery confirmation request packet for requesting a return of the delivery confirmation packet for the aggregate packet to the receiving side of the packet in the above configuration. Further, the communication unit may further transmit the delivery confirmation request packet to the receiving device. That is, in the case of this configuration, it is possible to send a delivery confirmation request packet for requesting a return of a delivery confirmation packet for the aggregate packet to the receiving side of the packet.

  Further, the communication device according to the present invention generates a delivery confirmation request packet for requesting the reception side of the packet to return a delivery confirmation packet for each of the packets included in the aggregate packet in the above configuration. It is good also as a structure further provided with the delivery confirmation request | requirement means to perform, and the said communication part further transmits the said delivery confirmation request packet with respect to the said receiving device. In other words, in the case of this configuration, it is possible to send a delivery confirmation request packet for requesting the reception side of the packet to return a delivery confirmation packet for each of the packets included in the aggregate packet.

  Further, the communication device according to the present invention has a configuration in which, in the above configuration, the communication unit includes a plurality of transmission antennas, and a plurality of aggregate packets generated by the aggregate packet generation unit are distributed to each transmission antenna and transmitted. Also good. According to this configuration, it is possible to distribute and transmit a plurality of aggregate packets to each transmission antenna, so that the transmission rate can be improved compared to the case where transmission is performed by one transmission antenna.

  The communication apparatus according to the present invention may be configured such that, in the above configuration, the communication unit transmits the same delivery confirmation request packet to each transmission antenna. In this case, since it is not necessary to generate a different delivery confirmation request packet for each transmission antenna, the processing can be simplified.

  Further, in the communication device according to the present invention, in the above configuration, the delivery confirmation request packet includes information specifying a reception side communication device that is a destination of the aggregate packet or the packet that is a request for delivery confirmation. It may be configured to include. According to this configuration, since the information for specifying the destination communication device as the destination is included in the delivery confirmation request packet, even if the same delivery confirmation request packet is transmitted by a plurality of transmission antennas, the information corresponding to the destination is used. It can be expected that an appropriate delivery confirmation is returned from the communication device.

  The communication apparatus according to the present invention is a communication apparatus that receives an aggregate packet from the communication apparatus, and an extraction unit that extracts an aggregate packet or a packet destined for the communication apparatus from the aggregate packet; A reception state detection unit that detects a reception state of the aggregate packet or the packet extracted by the extraction unit; a delivery confirmation generation unit that generates a delivery confirmation packet for the transmission packet according to a detection result by the reception state detection unit; and the delivery By adopting a configuration including a communication unit that transmits a confirmation packet, it is possible to cope with the reception device of the communication device.

  Further, in the communication apparatus according to the present invention, in the above-described configuration, the delivery confirmation request packet is a target for requesting delivery confirmation for the aggregate packet or each communication apparatus on the receiving side that is the destination of the packet. It is good also as a structure containing the information which sets the reply time of a delivery confirmation packet. According to this configuration, it is possible to prevent a situation in which transmission of delivery confirmation from each communication device collides.

  A communication apparatus according to the present invention is a communication apparatus that receives an aggregate packet from the communication apparatus, and is included in the aggregate packet or the reception state detection unit that detects a reception state of the packet. A reply time extracting means for extracting reply time information, a delivery confirmation generating means for generating a delivery confirmation packet for the aggregate packet or the packet according to a detection result by the reception state detecting means, and the delivery confirmation packet. It is possible to correspond as a receiving device of the communication device.

  An embodiment of the present invention is described below with reference to the drawings.

(Configuration of communication network system)
FIG. 3 shows a schematic configuration of the communication network system according to the present embodiment. As shown in the figure, this communication network system sends a stream from a transmission device 3 to a reception device 4 through a transmission side communication device (communication device) 1 and a reception side communication device (communication device) 2. Data and / or data is transmitted. In the figure, an example in which a plurality of receiving side communication devices 2 and a plurality of receiving devices 4 are provided is shown, but a configuration in which only one receiving device is provided is also considered. A plurality of transmission side communication devices 1 and transmission devices 3 may be provided.

  The transmission device 3 is a device capable of transmitting stream data such as moving image data and other data to an external device. Specifically, the transmission device 3 is configured by a moving image reproduction device such as a DVD (Digital Versatile Disk) player, a DVD recorder, and an HDD recorder, a broadcast reception device such as a BS / CS tuner, and the like.

  The receiving device 4 is a device that performs processing based on the received stream data and other data. Specifically, the receiving device 4 is configured by, for example, a display device that displays moving image data as received stream data.

  The stream data / data output from the transmission device 3 is transmitted to the transmission side communication device 1. Then, the transmission side communication device 1 transmits the stream data / data to the reception side communication device 2 by wireless communication. When receiving the stream data / data sent from the transmission side communication device 1 via wireless, the reception side communication device 2 transmits this to the reception device 4. Through the above processing, transmission of stream data / data from the transmission device 3 to the reception device 4 is performed.

  In the present embodiment, a system in which the transmission device 3 and the transmission-side communication device 1 are provided as separate devices is shown. However, the present invention is not limited to this. The configuration may be such that the function of the device 1 is provided. Similarly, the receiving device 4 may have a configuration in which the function of the receiving communication device 2 is provided.

(Configuration of transmitting communication device)
FIG. 1 is a functional block diagram illustrating a schematic configuration of the transmission-side communication device 1. As shown in the figure, the transmission side communication device 1 includes a communication unit 5, an aggregate packet generation unit (aggregate packet generation unit / packet generation unit) 6, a BAR generation unit (delivery confirmation request unit) 7, and a delivery confirmation reception unit 8. A reply time calculation unit (reply time calculation means) 9 and a transmission packet information storage unit 10 are provided.

  The communication unit 5 is a block that performs communication processing in the transmission-side communication device 1 and also has a function as a communication interface. The communication unit 5 transmits the aggregate packet generated by the aggregate packet generation unit 6 and the BAR generated by the BAR generation unit 7 to the reception-side communication device 2 via wireless communication, and the reception-side communication device 2 A process of sending ACK or BA received via wireless communication to the delivery confirmation receiving unit 8 is performed.

  Note that the communication unit 5 may be configured to perform transmission using one antenna as in the configuration illustrated in FIG. 36A, or may be configured as illustrated in FIG. 36C or FIG. 47. Thus, the structure which transmits using a some antenna may be sufficient.

  The BAR generation unit 7 is a block that reads information on a packet that has already been transmitted and that has not been acknowledged, and that is stored in the transmission packet information storage unit 10, and generates a BAR at a predetermined timing.

  The reply time calculation unit 9 transmits the same BAR to a plurality of receiving side communication devices 2..., And when the destination of a packet requesting a BA reply by the BAR is a plurality of receiving side communication devices 2. This is a block for calculating a reply time for setting at which timing a BA should be returned to each receiving side communication device 2.

  The delivery confirmation receiving unit 8 is a block that updates the packet information stored in the transmission packet information storage unit 10 based on the ACK or BA received from the receiving communication device 2.

  The aggregate packet generation unit 6 is a block that performs a process of configuring the packet input from the transmission device 3 into a transmission packet for transmission and sending the packet to the communication unit 5. Here, the aggregate packet generation unit 6 may generate a single aggregate packet by combining a plurality of packets input from the transmission device 3, or may transmit a packet based on the single packet input from the transmission device 3. May be generated. In the following embodiments and examples, the aggregate packet is configured as a header + MPDU, and each packet included in the aggregate packet is an MPDU or MSDU.

  The aggregate packet generator 6 includes a packet buffer 11, a common information extractor (common information extractor) 12, an aggregate packet constructer (aggregate packet reconstructor) 13, an error check processor (error check processor) 14, and A reply time calculation unit (reply time calculation means) 15 is provided.

  The packet buffer 11 is a buffer that temporarily stores one or more packets input from the transmission device 3 as an upper layer. The common information extraction unit 12 is a block that performs processing for extracting information common to all the plurality of packets stored in the packet buffer 11. Details of this common information will be described later.

  The error check processing unit 14 is a block that performs error check processing on the aggregate packet. Details of the error check process will be described later.

  The reply time calculation unit 15 transmits one aggregate packet to the plurality of receiving side communication devices 2... And receives a plurality of destinations of packets for requesting an ACK reply to the packet included in the aggregate packet. This is a block for calculating a return time for setting at which timing an ACK should be returned to each receiving side communication device 2 when the receiving side communication device 2 is used.

  The collective packet constructing unit 13 collects one or more packets stored in the packet buffer 11 based on the processing by the common information extracting unit 12, the error check processing unit 14, and the reply time calculating unit 15 into one set. It is a block that performs processing to construct a packet.

  The transmission side communication device 1 needs to include all the components included in the aggregate packet generation unit 6, the BAR generation unit 7, the delivery confirmation reception unit 8, the reply time calculation unit 9, and the transmission packet information storage unit 10. It is only necessary to have functions required in the embodiments described later.

(Configuration of receiving side communication device)
FIG. 2 is a functional block diagram illustrating a schematic configuration of the receiving-side communication device 2. As shown in the figure, the receiving side communication device 2 includes a communication unit 21, an ACK generation unit (delivery confirmation generation unit) 22, a BA generation unit (delivery confirmation generation unit) 23, a destination information extraction unit (extraction unit) 24, The BAR receiving unit 25, a reply time extracting unit (reply time extracting unit) 26, a packet buffer 27, a reception state detection unit (reception state detection unit) 28, and a reception packet information storage unit 29 are provided.

  The communication unit 21 is a block that performs communication processing in the receiving-side communication device 2 and also has a function as a communication interface. The communication unit 21 transmits the ACK generated by the ACK generation unit 22, the BA generated by the BA generation unit 23, and the like to the transmission side communication device 1 via wireless communication, and also transmits wireless communication from the transmission side communication device 1. A process of sending the aggregate packet, BAR, etc. received via the packet buffer 27 and the BAR receiver 25 via the destination information extraction unit 24 is performed.

  The communication unit 21 may be configured to receive using one antenna as in the configuration illustrated in FIG. 36A, or may be configured as illustrated in FIG. 36C or FIG. Thus, the structure which receives using a some antenna may be sufficient.

  The destination information extraction unit 24 is a block that performs processing for extracting information on a part destined for the own apparatus from the aggregate packet and BAR received by the communication unit 21. The destination information extraction unit 24 sends the packet extracted from the aggregate packet and the information extracted from the BAR to the packet buffer 27.

  The packet buffer 27 is a buffer that temporarily stores received packets. Of the packets stored in the packet buffer 27, a packet as actual data is sent to the receiving device 4 as an upper layer.

  The reception state detection unit 28 is a block that detects a reception state of a packet addressed to its own device, that is, whether reception has succeeded or failed. The reception state detected by the reception state detection unit 28 is stored in the reception packet information storage unit 29.

  The BAR receiving unit 25 is a block that performs processing to read the reception state of a packet that is a delivery confirmation target from the received packet information storage unit 29 and send the information to the BA generation unit 23 when receiving a BAR addressed to the own device. is there.

  The BA generation unit 23 is a block that performs processing to generate a BA based on the reception state of a packet that is a delivery confirmation target transmitted from the BAR reception unit 25 and send the BA to the communication unit 21. The ACK generation unit 22 is a block that performs processing for generating an ACK based on the reception state detected by the reception state detection unit 28 and sending the ACK to the communication unit 21.

  The reply time extracting unit 26 is a block that performs processing of extracting reply time information from the packet and BAR stored in the packet buffer 27 and sending the reply time information to the communication unit 21. The communication unit 21 transmits the BA generated by the BA generation unit 23 and the ACK generated by the ACK generation unit 22 according to the reply time information.

  The receiving side communication device 2 includes an ACK generation unit 22, a BA generation unit 23, a destination information extraction unit 24, a BAR reception unit 25, a reply time extraction unit 26, a reception state detection unit 28, and a reception packet information storage unit 29. It is not necessary to provide all of them, and it is sufficient to have functions required in the embodiments described later.

(Embodiment 1)
One embodiment of the present invention will be described below. In the present embodiment, the format of a packet generated by the collective packet generation unit 6 when different MSDUs are transmitted by a plurality of antennas by MIMO will be described.

  First, common information (common information) of each MSDU is referred to as a header A, and a portion of the header that is not common is referred to as a header B. As a method for transmitting the header A, there are the following three examples.

  A first packet transmission example is shown in FIG. In this case, the case where two transmitting antennas are used is shown. In order to maintain compatibility with a transmitter that transmits using a single conventional antenna, SP (Short Preamble), LP (Long Preamble), and PLCP (Physical Layer Convergence Protocol) are initially transmitted from one antenna. In this example, the header A is transmitted by the same antenna after this, and then MP (MIMO Preamble) is transmitted by all the antennas. Next, the header B of each MSDU transmitted by each antenna is transmitted. However, since the header A is a part of the MPDU and the MPDU is a part after the MP, the header A is preferably transmitted after the MP.

  A second packet transmission example is shown in FIG. In this case, the header A as common information is transmitted after the MP. In addition, the header A is divided into a header A1 and a header A2, and transmitted by different antennas. However, if transmission by any of the antennas fails, transmission of the entire header A fails, and all transmissions by antennas with good communication conditions have also failed.

  A third packet transmission example is shown in FIG. In this case, the same common header A is transmitted by all antennas, and then each header B is transmitted. By transmitting the common header A with all antennas, the problems of the first packet transmission example and the second packet transmission example can be solved.

(Embodiment 2-1)
Other embodiments of the present invention are described below. In the present embodiment, the format of a packet generated by the aggregate packet generator 6 when the error check processor 14 performs an error check process for each MSDU included in the aggregate packet will be described. As described above, by performing error check for each MSDU, even if one MSDU in the MPDU is lost, it is possible to succeed in communication of other MSDUs. Further, since it is possible to request delivery confirmation for each MSDU, it is possible to retransmit only the MSDU that has failed to be transmitted, and to improve the efficiency of transmission.

  A packet configuration example in the present embodiment is shown in FIG. In the figure, H1, H2, and H3 indicate headers of MSDU1, MSDU2, and MSDU3, CH is a CRC applied to H1, H2, and H3, and C1, C2, and C3 are MSDU1, MSDU2, This is a CRC applied to each MSDU3.

  As shown in the figure, the CRC check is performed for each MSDU. In addition, since the positioning information of each MSDU in the MPDU is necessary for generating an ACK on the receiving side, the header including the transmission speed and length information of each MSDU is transmitted together at the beginning of the MPDU. In this case, since the reliability of the header information is important, a CRC check is also performed on the header information.

  In the above example, CRC is performed for each MSDU. However, when the state of the transmission path is relatively good, a check may be performed with one CRC for each of a plurality of MSDUs. In this way, since the number of CRCs can be reduced, the size of the MPDU can be further reduced. In the example shown in FIG. 8, the CRC check is performed by C2 for MSDU2 and MSDU3. Details of the packet including the CRC will be described later in an embodiment described later.

  As described above, when the state of the transmission path is relatively bad, it is possible to ensure a success rate of MSDU communication above a certain level by performing CRC for each MSDU as in the case shown in FIG. . Further, as the condition of the transmission path becomes better, the length of the MPDU can be reduced by checking a plurality of MSDUs together with one CRC as in the example shown in FIG.

(Embodiment 2-2)
Still another embodiment of the present invention will be described below. In the present embodiment, a description will be given of processing when an error occurs in the ACK for the aggregate packet when the transmission side communication apparatus 1 performs transmission by the aggregate packet described in Embodiment 2-1.

  When processing defined by IEEE 802.11 is performed, a packet is retransmitted when an error occurs in ACK. In the case of an aggregate packet, as shown in FIG. 21, ACK is a bitmap including the delivery status of all transmitted MSDUs, and even if an error occurs in ACK, not all MSDUs in the aggregate packet are necessarily in error. . For this reason, in this embodiment, as shown in FIG. 48, at least a point after PIFS (Point coordination function Inter Frame Space: 25 μs in the case of IEEE 801.11a) after the end of reception of an ACK in which an error has occurred. Thus, a BAR for confirming all the MSDUs in the aggregate packet is generated, and this BAR is transmitted to the receiving-side communication device 2. Thereafter, the delivery confirmation of each MSDU in the aggregate packet is performed by the BA returned from the receiving side communication device 2. Thus, when an error occurs in ACK, it is possible to confirm which MSDU has failed to be delivered by transmitting a relatively short BAR rather than retransmitting the entire aggregate packet. Become. Since BA and ACK are both configured by a bitmap indicating the delivery status of each MSDU, the format of BA may be the same as that of ACK.

  Further, as shown in FIG. 49, if an error occurs in the header part (preamble & header, H1, H2, H3, CH in FIG. 49) of the aggregate packet transmitted in the transmitting communication device 1, the transmitting communication device 1 cannot confirm the delivery of the aggregate packet. That is, the receiving side communication device 2 cannot receive the aggregate packet and therefore does not send back an ACK. Therefore, after transmitting the aggregate packet, the transmission side communication apparatus 1 enters the ACK reception process, but does not receive the ACK, and therefore becomes TIME OUT. In this case, the transmission side communication device 1 may retransmit the aggregate packet. For example, when the same bandwidth is shared by a plurality of terminals, the time for which data can be transferred to each terminal is determined, and if there is still room for this transferable time, retransmission of the aggregate packet is Performed after TIME OUT. For example, when there is an MSDU that has expired in the aggregate packet at the time of an error, the MSDU is not retransmitted.

  As shown in FIG. 50, when the aggregate packet number for identifying the aggregate packet is set in the aggregate packet, instead of using a long BAR including information of all MSDUs to be retransmitted, the transmission side communication apparatus 1 An ACK retransmission request packet including the aggregate packet number may be used. In this case, since the ACK retransmission request packet requests retransmission of ACK by designating the aggregate packet number, the length can be shortened compared to BAR.

  When receiving the ACK retransmission request packet, the receiving-side communication apparatus 2 returns a bitmap containing the delivery status of the MSDU included in the aggregate packet specified by the aggregate packet number as an ACK. Since the receiving side communication device 2 may not receive the aggregate packet specified by the aggregate packet number, or there is a possibility that the information for generating the ACK is lost, it is determined whether the ACK is valid or not. An ACK valid flag may also be included. If the ACK valid flag indicates that the ACK is not valid, the ACK may not include a bitmap.

  For example, as shown in FIG. 51, the entire aggregate packet with the aggregate packet number = 1 becomes an error, and the transmission side communication device 1 is in a channel busy state (a state where the reception power level is equal to or higher than a certain threshold, Alternatively, the transmission side communication apparatus 1 may transmit an ACK retransmission request packet including the aggregate packet number = 1 when the packet reception is not normally performed. Since the receiving side communication apparatus 2 has not received the aggregate packet with the aggregate packet number = 1, the ACK valid flag may be set to be invalid and an ACK may be returned without entering the ACK bitmap. In this case, the transmission side communication device 1 may retransmit the aggregate packet.

  As is clear from the above description, the receiving side communication apparatus 2 stores the last transmitted ACK information and its aggregate packet number, and hassle to reconstruct the ACK packet when the ACK retransmission request packet is received. Can be omitted. For example, when the same bandwidth is shared by multiple terminals, the time that each terminal can transfer data is determined, and if there is still room for this transferable time, retransmission of the aggregate packet is not effective You may go after ACK. Further, for example, when there is an MSDU that has expired in the aggregate packet at the time of an error, the MSDU need not be retransmitted.

  In this embodiment, an example in which CRC is applied to each MSDU of the aggregate packet is used. However, an aggregate packet in which CRC is applied to a plurality of MSDUs as shown in FIG. 8 may be used.

(Embodiment 3)
Still another embodiment of the present invention will be described below. In the present embodiment, when the destination of the packet included in the aggregate packet is a plurality of receiving side communication devices 2 (hereinafter, the transmitting side and receiving side communication devices may be simply referred to as MAC), A packet format including a reply time when a delivery confirmation should be returned will be described.

  As described above, in order to avoid ACK collision, each receiving-side communication device 2 needs to return ACK at different timings. Here, if each receiving side communication device 2 can confirm the order in which the ACK is returned, the receiving side communication device 2 can calculate the time when the ACK should be returned based on the number of bytes of the ACK and the transmission speed in the other receiving side communication devices 2. it can. The number of bytes of ACK can be confirmed by the number of MSDUs confirmed by ACK. However, 802.11 transmission rates are not known in all cases. When STA (Station) and AP (Access Point) communicate, the transmission rate of ACK is known, but in the case of communication between STA and STA, it is unknown.

  In this way, when the transmission rate of ACK is unknown, the communication station that has received the MSDU returns the ACK when the MSDU header includes the reply time at which the ACK should be returned to each communication device (STA). I know what to do. This reply time is calculated by the reply time calculation unit 15, and the reply time calculated here is included in the header of each MSDU by the aggregate packet construction unit 13. An example of a packet including a reply time will be described in detail in an embodiment described later.

  Similar to the case where all MSDUs of an MPDU are communicated to one communication station, when the MSDU is communicated to another communication station, a CRC check is performed for each MSDU if the transmission path condition is bad. A plurality of MSDUs may be combined into one CRC as the road condition improves.

(Embodiment 4)
Still another embodiment of the present invention will be described below. In the present embodiment, the format of a packet constituting the BAR will be described. As described above, the conventional 802.11e BAR / BA can confirm only 64 ranges of MSDU at a time. However, when using packet aggregation, it is preferable that delivery confirmation for more packets can be performed. Therefore, in the present embodiment, in order to realize a BAR that can support 64 or more MSDUs, the BAR generation unit 7 in the transmission side communication device 1 selects a BAR including information of all MSDUs to be confirmed. At the same time, the BA generating unit 23 in the receiving side communication device 2 generates a BA composed of a bitmap indicating whether each MSDU of the BAR has been successfully received or failed.

  Further, when MSDU is transmitted to a plurality of receiving side communication devices 2, the BAR generating unit 7 should confirm the information of the receiving side communication device 2 to be confirmed for delivery and the delivery for each receiving side communication device 2. A BAR including MSDU information is generated. Note that details of examples of BAR and BA packets will be described in the embodiments described later.

(Embodiment 5)
Still another embodiment of the present invention will be described below. In the present embodiment, a packet format when a packet to be included in an aggregate packet is divided into a plurality of packets and each divided packet is allocated to a plurality of aggregate packets will be described.

  As described above, when data is transferred using MIMO, it is necessary to transmit data simultaneously using all the transmission antennas. In this case, the transmission time of a packet transmitted from each transmission antenna varies due to a difference in transmission speed between the transmission antennas and a difference in size of a packet transmitted in each transmission antenna. That is, there is a problem that a band is wasted with an antenna having a shorter transmission time.

  On the other hand, in the present embodiment, the aggregate packet construction unit 13 divides the packets included in the aggregate packet into different aggregate packets so that the lengths of the aggregate packets transmitted by the respective transmission antennas are substantially equal. A collective packet is generated so as to be allocated. As a result, it is possible to align the transmission time of one collective packet by each transmission antenna, so that the band utilization efficiency can be improved.

  FIG. 9 shows an example of an aggregate packet transmitted by each transmission antenna when two transmission antennas are used. In the example shown in the figure, two transmission antennas 1 (transmission speed 24 MBps) and transmission antennas 2 (transmission speed 36 MBps) having different transmission speeds are used.

  The first MPDU transmitted from the antenna 1 includes the entire MSDU1 and one MSDU2_1 / 2 of the divided packets obtained by dividing the MSDU2 into two. Further, the first MPDU transmitted from the antenna 2 includes the other MSDU2_2 / 2 of the divided packets obtained by dividing MSUDU2 into two and the entire MSDU3. In this way, by adjusting the size of the packet distributed to each transmission antenna, it is possible to align the transmission time in each transmission antenna and improve the band utilization efficiency.

  First, an example in which a collective packet is transmitted to one communication apparatus using a plurality of antennas will be described. Similar to Packet Aggregation, the receiving-side communication device 2 returns an ACK to each MSDU or each divided part of the divided MSDU. Re-transmission of the divided MSDU is limited to the divided portion where the transmission has failed. Here, the ACK for the MSDU or the divided part of the MSDU transmitted from one transmission antenna is transmitted from the transmission antenna on the reception side corresponding to the reception antenna that has received the corresponding MSDU or the divided part of the MSDU. In the example shown in FIG. 10A, ACK for antenna 1 corresponds to MSDU1 and MSDU2_1 / 2, and ACK for antenna 2 corresponds to MSDU2_2 / 2 and MSDU3. However, in this case, if transmission of an ACK to an MSDU or a divided part of the MSDU sent from one transmission antenna fails, these retransmissions are performed even if the communication itself of the MSDU or the divided part of the MSDU is successful. become.

  On the other hand, in the example shown in FIG. 10B, the ACK for antenna 1 and the ACK for antenna 2 correspond to all MSDUs transmitted by antenna 1 and antenna 2, respectively, or divided parts of MSDUs. Yes. In this way, even if transmission of ACK fails in one antenna, if transmission of ACK is successful in other antennas, delivery confirmation for MSDUs transmitted from all antennas or divided parts of MSDUs is performed. Can be performed. As a result, redundant retransmission of packets can be avoided and bandwidth utilization efficiency can be improved. In FIGS. 10A and 10B, only the MPDU portion in the aggregate packet is shown, and the header portion in the aggregate packet is not shown.

  Next, a case where MSDUs having different destination communication devices are included in an MPDU as an aggregate packet will be described. In this case, similar to Packet Aggregation, the reply time at which an ACK should be returned for each communication device is stored in the header of the MPDU or MSDU.

  Even in the burst mode, BAR / BA of all antennas can be made to correspond to all MSDUs transmitted by all antennas. Further, since the communication status differs for each antenna, it is preferable that the divided MSDUs communicate with each other in the burst communication. For example, in the example shown in FIG. 11A, MSDU2 is divided into two divided parts MSDU2_1 / 2 and MSDU2_2 / 2, and the divided parts are transmitted separately by antenna 1 and antenna 2.

  Here, if the communication status of the antenna 2 is bad, only the MSDU2_2 / 2 fails and is retransmitted in the next burst. There is no problem when the MSDU is normal data, but when the MSDU is a QoS packet, there is a possibility of packet loss due to the expiration date due to slow retransmission. As shown in FIG. 11 (a), when the entire MSDU2 is lost due to an error in only the MSDU2_2 / 2, the MSDU2_1 / 2 is not used even though the transmission is successful. That is, the bandwidth utilization efficiency is reduced.

  On the other hand, in the example shown in FIG. 11B and FIG. 11C, MSDU2 is divided into two divided parts MSDU2_1 / 2 and MSDU2_2 / 2, and each divided part is transmitted by the same antenna 1. Yes. In this case, as shown in FIG. 5B, when the communication status of the antenna 2 is poor, both the MSDU2_1 / 2 and the MSDU2_2 / 2 transmitted by the antenna 1 are likely to be successfully transmitted. As shown in (c), when the communication status of the antenna 1 is poor, there is a high possibility that both MSDU2_1 / 2 and MSDU2_2 / 2 transmitted by the antenna 1 will fail in transmission. In other words, when a packet is divided and transmitted, by transmitting the divided packet with the same antenna, only one of the divided packets fails to be transmitted, resulting in a situation where the divided packet that has been successfully transmitted is wasted. Can be suppressed. Thus, the bandwidth utilization efficiency can be improved.

  As with ACK, BAR / BA corresponds to all MSDUs transmitted during a burst and the divided parts of MSDUs. BAR / BA communicated with all antennas is the same.

  Further, when MSDU is transmitted to a plurality of communication apparatuses, MSDU to be confirmed for each communication apparatus and the time at which each communication apparatus should return BA are included in one BAR. The BA reply time is used only when necessary.

  Even when ACK is used, MPDUs can be communicated continuously in bursts. In this case, the MSDU divided in the same manner as BAR / BA can be transmitted by the same antenna. This case is shown in FIG.

  When the last MPDU is transmitted, the MSDU cannot be divided into two MPDUs with the same antenna, so each part of the MSDU may be transmitted with a different antenna.

(Outline of MAC header)
Here, an outline of a MAC header included in a packet transmitted and received in the embodiment described below will be described below with reference to FIGS. 13 (a) and 13 (b). Note that the MAC header shown here is only an overview, and in each embodiment described later, the MAC header configuration is suitable for that form.

  FIG. 13A shows a configuration example of the MPDU MAC header 200. As shown in the figure, the MPDU MAC header 200 includes an MPDU type 205 and an MPDU header 230. The MPDU header 230 includes an address part 210, a transmission rate 220, and other information 225. Note that the order of information in the MPDU MAC header 200 is arbitrary.

  FIG. 13B shows a configuration example of the MSDU MAC header 250. As shown in the figure, the MSDU MAC header 250 includes an address part 210 and an MSDU header 260. The MSDU header 260 includes an MSDU type 255, a transmission rate 220, and other information 225. Note that the order of information in the MSDU MAC header 250 is arbitrary.

  The address part 210 is an area indicating address information such as Source Address (SA) and Destination Address (DA). The transmission rate 220 is an area indicating transmission rate information when the packet is transmitted. Here, for example, in the case of using MIMO for transmitting one signal by a plurality of antennas, the transmission rate of a packet transmitted by each transmission antenna is designated.

  The MSDU type 255 is an area indicating the type of the MSDU packet. Examples of the MSDU packet include an ACK packet, a BAR packet, a BA packet, a data packet, and a QoS packet.

  The MPDU type 205 is an area indicating the type of the MPDU packet. Examples of the types of MPDU packets include ACK packets, BAR packets, BA packets, data packets, QoS packets, and congestion packets. A congestion packet is a type of MPDU that can include different MSDUs of MSDU type 260 in one MPDU. If it is not a congested packet, the MSDU type of all MSDUs in the MPDU becomes the MPDU type. The MPDU type 205 may also include an Ack Policy flag.

  Other information 225 includes Ack Policy, More Flag, reply time Flag, and the like. Ack Policy is a flag that specifies whether to use ACK or BAR / BA. More Flag is a flag provided at the end of each MSDU to indicate how the MSDU is divided and transmitted when divided into a plurality. By setting the More Flag of the last part of the divided MSDU to 0 and other MSDUs to 1, the receiving side can recognize how the MSDU has been divided.

  The reply time Flag is a flag indicating whether or not the MPDU includes information regarding the time to reply Ack or BA.

(Example 1-1)
In this embodiment, Packet Aggregation is used, 1) the destination is only one MAC, 2) the MAC header is compatible with the conventional (such as IEEE 802.11), and 3) CRC is used for the entire MPDU. The packet format of the MPDU in this case will be described.

  In this embodiment, compatibility with the conventional method can be maintained by applying the conventional MSDU MAC header to all MSDUs. Further, by making each MSDU a conventional MPDU, it is possible to transmit other types of packets using the same MPDU. Note that examples of conventional MPDU include those based on IEEE802.11 and IEEE802.11e.

  In this embodiment, the packet aggregation MPDU type 205 is a data packet, a QoS packet, or a congested packet.

  A schematic configuration of a packet used in the present embodiment is shown in FIG. As shown in the figure, the packet includes an MPDU type 300, an MSDU number 310, a MAC information unit 320, and an MSDU unit 340.

  The MPDU type 300 corresponds to the MPDU type 205 shown in FIG. The MSDU number 310 indicates the number of MSDUs transmitted by the packet. In this example, the number of MSDUs is n.

  In the case of the present embodiment, the MAC information unit 320 is the MAC information unit example 400 shown in FIG. That is, the MAC information unit 320 includes a transmission rate 405 and n pieces of MAC information 410.

  The transmission rate 405 corresponds to the transmission rate 220 shown in FIG. The MAC information 410 includes an MSDU length / sequence number 420. The MSDU length / sequence number 420 indicates the byte length of each MSDU and the sequence number of the MSDU.

  The MSDU unit 340 is an MSDU unit example 650 shown in FIG. As shown in the figure, the MSDU unit 340 includes n conventional MPDUs 655... And the CRC 670 of the last MPDU as a whole. Examples of conventional MPDUs include those that comply with IEEE 802.11 and IEEE 802.11e. Note that the ACK packet may be of the same format as the conventional 802.11.

  As described above, in this embodiment, the CRC 670 is applied to the entire MPDU. Thus, by applying CRC to the entire MPDU, it is possible to shorten the length of the MPDU as compared with the case where CRC is applied to each MSDU included in the MPDU.

  In order to correct errors occurring in transmission / reception, generally Viterbi, Turbo Code, LDPC (Low Density Parity Check), etc. are used for the entire MPDU including CRC. Also, pad bits generated from these processes are added after the CRC.

(Example 1-2)
In this embodiment, Packet Aggregation will be used to explain the MPDU packet format when 1) the destination is only one MAC, 2) the address part is shared, and 3) CRC is used for the entire MPDU.

  In the present embodiment, it is possible to make the MAC information unit 320 small by sharing the address unit among all the MSDUs. Further, by using an independent MSDU header for each MSDU, it is possible to transmit another type of packet using the same MPDU.

  The schematic configuration of the packet used in this embodiment is the same as that shown in FIG.

  In this embodiment, the MAC information unit 320 is the MAC information unit example 500 shown in FIG. That is, the MAC information unit 320 includes an address unit 510 and n MSDU headers 520. Each header 520 includes an MSDU length / sequence number 530 and an MSDU header 540. In the header 520, the order of the MSDU length / sequence number 530 and the MSDU header 540 is arbitrary.

  In the present embodiment, the MSDU unit 340 is an MSDU unit example 700 shown in FIG. As shown in the figure, the MSDU unit 340 includes n MSDUs 710... And a CRC 740 for the last MPDU as a whole.

  In the present embodiment, the order of the MSDU number 310 and the address part 510 in the MAC information part 320 can be reversed.

(Example 1-3)
In this embodiment, a packet aggregation of MPDU when 1) the destination is only one MAC, 2) the MPDU header 230 is shared, and 3) the CRC is used for the entire MPDU will be described.

  In this embodiment, it is possible to further reduce the MAC information unit 320 by eliminating the MSDU type and sharing the MPDU header 230 by all MSDUs. Since there is no MSDU type, all MSDU types are unified to the type shown in the MPDU type 205. In this case, examples of the MPDU type 205 include a data packet and a QoS packet, and a congested packet cannot exist.

  The schematic configuration of the packet used in this embodiment is the same as that shown in FIG.

  In this embodiment, the MAC information unit 320 is the MAC information unit example 600 shown in FIG. That is, the MAC information unit 320 includes an MPDU header 610 and n MSDU length / sequence numbers 620.

  In the case of the present embodiment, the order of the MSDU number 310 and the MPDU header part 610 in the MAC information part 320 can be reversed.

(Example 1-4)
This example is a combination of Example 1-1 and Example 1-3. When transmitting a packet of which the MPDU type is a congestion type, the MPDU is in the format of the embodiment 1-1. When transmitting a packet of the data type or the QoS type as the MPDU type, the MPDU is the same as that of the embodiment 1-3. Format. In this case, it is possible to maintain compatibility with the conventional case when transmitting a congestion type packet, and it is possible to reduce the size of the MPDU when transmitting a data type or QoS type packet.

(Example 1-5)
This example is a combination of Example 1-2 and Example 1-3. When transmitting a packet of which the MPDU type is a congestion type, the MPDU is in the format of the embodiment 1-2, and when transmitting a packet of the data type or the QoS type as the MPDU type, the MPDU of the embodiment 1-3 is used. Format. In this case, the size of the MPDU can be reduced in both types.

(Example 1-6)
In this example, CRC is applied to each of the MSDUs of Example 1-1 to Example 1-5. Also, CRC is applied collectively to the MPDU type, the number of MPDUs, and the MAC information part. Thus, it is possible to increase communication reliability by applying CRC to the header part of the MPDU and each MSDU.

  A schematic configuration of a packet used in this embodiment is shown in FIG. As shown in the figure, the packet includes a CRCH 330 in addition to the MPDU type 300, the MSDU number 310, the MAC information unit 320, and the MSDU unit 340. The CRCH 330 is a CRC that is arranged after the MPDU type 300, the MSDU number 310, and the MAC information unit 320, and is applied to the MPDU type 300, the MSDU number 310, and the MAC information unit 320.

  FIG. 17B shows a configuration in which the MSDU example 650 shown in FIG. 14C is applied to this embodiment. As shown in the figure, the MSDU unit 340 includes n conventional MPDUs 655... And n CRCs 660 arranged after each conventional MPDU 655.

  FIG. 17C shows a configuration in which the MSDU unit example 700 shown in FIG. 15B is applied to this embodiment. As shown in the figure, the MSDU unit 340 includes n MSDUs 710... And n CRCs 720 arranged after each MSDU 710.

  Note that Viterbi, Turbo Code, or LDPC processing is usually used to correct errors that occur in transmission and reception. Also, pad bits generated from these processes are added after each CRC. The above processing is applied to a portion (including CRCH / CRC) corresponding to CRCH / CRC. For example, in FIG. 20, the above processing is applied to the MAC header + CRCH + pad bit and each conventional MPDU or MSDU + CRC + pad bit.

  According to the present embodiment, the reliability can be increased by applying the CRC for each MSDU. However, in order to confirm the communication status of each MSDU, the ACK needs to include the communication status of all MSDUs. The ACK for this purpose is composed of an ACK MAC header 1350 and n bits 1360 as shown in FIG. The number of bits 1360 corresponds to the number of MSDUs included in the packet to be ACKed. Each bit 1360 indicates the communication status of the MSDU included in the packet to be ACKed. For example, if the bit is 1, it indicates communication success, and if it is 0, it indicates communication failure. Further, the order of each bit 1360 corresponds to the order of each MSDU confirmed by the MAC information part included in the packet to be ACKed.

(Example 2-1)
In the present embodiment, an MPDU packet format in which CRC is applied to each of a variable number of MSDUs will be described. According to the present embodiment, since CRC can be applied for each optimum number of MSDUs, it is possible to make a trade-off between the overall length of the MPDU and the reliability of the transmission path.

  A schematic configuration of a packet used in this embodiment is shown in FIG. As shown in the figure, the packet includes an MPDU type 800, an MSDU number 810, a MAC information part 820, a CRC part 830, a CRCH 835, and an MSDU part 840.

  The MPDU type 800, the MSDU number 810, the MAC information unit 820, and the CRCH 835 correspond to the MPDU type 300, the MSDU number 310, the MAC information unit 320, and the CRCH 330, and thus description thereof is omitted here.

  As shown in FIG. 18 (b), the CRC unit 830 includes a CRC unit number 1200 and CRC MSDU numbers 1210. The number of CRC parts 1200 is the number of CRCs included in the MSDU part 840, which is m. In the example, the first CRC MSDU number 1 is x1, and the last CRC MSDU number m is xm.

  As the MSDU unit 840, the MSDU unit example 1250 shown in FIG. 18C corresponding to FIG. 14C and the MSDU unit 1300 shown in FIG. 19 corresponding to FIG. 15B are applied. can do. As shown in these figures, the CRC is applied to each of a plurality of MSDUs, and the number of MSDUs to which each CRC is applied corresponds to the CRC MSDU number 1210. In the example MSDU portion 1250, the first CRC 1265 is applied to the first x1 conventional MPDU 1260 and the last CRC 1265 is applied to the last xm conventional MPDU 1260. Similarly, in the example MSDU portion 1300, the first CRC 1320 is applied to the first x1 MSDUs 1310 and the last CRC 1320 is applied to the last xm conventional MSDUs 1310. Others are the same as the corresponding contents, and the description is omitted here.

(Example 3-1)
In the present embodiment, an MPDU packet format in which CRC is applied to each of a fixed number of MSDUs will be described. According to the present embodiment, since CRC is applied to each of a plurality of MSDUs, it is possible to make a trade-off between the overall length of the MPDU and the reliability of the transmission path.

  A schematic configuration of a packet used in the present embodiment is shown in FIG. As shown in the figure, the packet includes an MPDU type 1400, an MSDU number 1410, a MAC information part 1420, a CRCMSDU number 1430, a CRCH 1435, and an MSDU part 1440.

  Since the MPDU type 1400, the MSDU number 1410, the MAC information unit 1420, and the CRCH 1435 correspond to the MPDU type 300, the MSDU number 310, the MAC information unit 320, and the CRCH 330, their descriptions are omitted here. .

  The CRCMSDU number 1430 indicates a fixed number of MSDUs between CRCs. In the example, the number of MSDUs is m.

  As the MSDU unit 1440, the MSDU unit example 1750 shown in FIG. 22B as corresponding to FIG. 14C, and the MSDU unit example shown in FIG. 22C corresponding to FIG. 15B. 1800 can be applied. As shown in these figures, CRC 1765 or CRC 1830 is applied to every m MSDU 1760 or MSDU 810. Also, the last CRC 1765 or 1830 is always applied to the end of the MPDU.

(Example 4-1)
In this embodiment, packet aggregation is used, 1) the destination is a plurality of MACs, 2) the MAC header is compatible with the conventional (IEEE802.11, etc.), and 3) CRC is used for the entire MPDU. The packet format of the MPDU will be described.

  In this embodiment, compatibility with the conventional method can be maintained by applying the conventional MSDU MAC header to all MSDUs. Further, by making each MSDU a conventional MPDU, it is possible to transmit other types of packets using the same MPDU. Note that examples of conventional MPDU include those based on IEEE802.11 and IEEE802.11e.

  In this embodiment, the packet aggregation MPDU type 205 is a data packet, a QoS packet, or a congested packet.

  A schematic configuration of a packet used in this embodiment is shown in FIG. As shown in the figure, the packet includes an MPDU type 2000, a MAC number 2010, a MAC information unit 2020, and an MSDU unit 2040.

  The MPDU type 2000 corresponds to the MPDU type 205 shown in FIG. The MAC number 2010 indicates the number of MACs that are destinations of the MSDU transmitted by the packet. In this example, the number of MSDUs is n.

  In the case of the present embodiment, the MAC information portion 2020 is the MAC information portion example 2100 shown in FIG. That is, the MAC information unit 2020 includes n pieces of MAC information 2110.

  Each MAC information 2110 includes an MSDU length / sequence number 2120 and a transmission rate 2130. The MSDU length / sequence number 2120 indicates the byte length of each MSDU and the sequence number of the MSDU. The transmission speed 2130 corresponds to the transmission speed 220 shown in FIG. The order of MSDU length / sequence number 2120 and transmission rate 2130 is arbitrary.

  The MSDU unit 2040 is an MSDU unit example 2400 shown in FIG. As shown in the figure, the MSDU unit 2400 includes n conventional MPDUs 2410... And a CRC 2440 of the entire last MPDU. Examples of conventional MPDUs include those that comply with IEEE 802.11 and IEEE 802.11e. Note that the ACK packet may be of the same format as the conventional 802.11.

  As described above, in this embodiment, CRC 2440 is applied to the entire MPDU. Thus, by applying CRC to the entire MPDU, it is possible to shorten the length of the MPDU as compared with the case where CRC is applied to each MSDU included in the MPDU.

  In order to correct errors occurring in transmission / reception, generally Viterbi, Turbo Code, LDPC (Low Density Parity Check), etc. are used for the entire MPDU including CRC. Also, pad bits generated from these processes are added after the CRC.

  In this embodiment, since the MSDU is transferred to a plurality of MACs, each MAC needs to return an ACK. The order of ACK replies by a plurality of MACs follows the order of MSDUs included in the MPDU, as shown in FIG. Here, in order to avoid collision due to ACKs being sent from a plurality of MACs at the same timing, each MAC needs to consider the timing at which ACKs should be returned. At this time, the MAC that should transmit the ACK can calculate the ACK reply time based on the ACK reply order, the number of ACK bytes, and the ACK transmission rate.

  However, there may be a case where each MAC cannot know the transmission rate of ACK, particularly the transmission rate of other MACs. In order to cope with such a case, the MAC information 2110 may include a reply time 2140 indicating a time at which the receiving side should return an ACK for the corresponding MSDU. In this case, the reply time Flag is included in the other information 225 shown in FIG. Thereby, the MAC that transmits the ACK can confirm that the reply time 2140 is included in the MAC information unit 2110.

(Example 4-2)
In this embodiment, a packet aggregation of MPDU in the case where 1) a destination is a plurality of MACs, 2) an address part is shared, and 3) CRC is used for the entire MPDU will be described using packet aggregation.

  In the present embodiment, the MAC information unit 2020 can be made smaller by sharing the address unit among all MSDUs. Further, by using an independent MSDU header for each MSDU, it is possible to transmit another type of packet using the same MPDU.

  The schematic configuration of the packet used in the present embodiment is the same as that shown in FIG.

  In the case of the present embodiment, the MAC information portion 2020 is the MAC information portion example 2200 shown in FIG. That is, the MAC information unit 2020 includes n MAC units 2210. Each MAC unit 2210 includes an MSDU number 2220, an address unit 2230, and a header 2250. Note that, as described in the embodiment 4-1, the reply time 2240 (corresponding to the reply time 2140 in the embodiment 4-1) may be included in the MAC unit 2210.

  The MSDU number 2220 indicates the number of MSDUs transmitted to each MAC. In the example, the MSDU number 2220 is set to i. k. Here, i indicates the corresponding MAC unit 2210, and k indicates the number of MSDUs transmitted to the MAC corresponding to the MAC unit 2210.

  The header 2250 includes i. k, each including an MSDU length / sequence number 2270 and an MSDU MAC header 2280.

  The order of the MSDU number 2220, the address part 2230, and the reply time 2240 is arbitrary. The order of the MSDU length / sequence number 2270 and the MSDU MAC header 2280 is also arbitrary.

  In the present embodiment, the MSDU unit 2040 is an MSDU unit example 2500 shown in FIG. As shown in the figure, the MSDU unit 2040 includes n. It consists of k MSDUs 2510... and CRC 2560 for the entire last MPDU. The order of the MSDUs 2510... Included in the MSDU unit 2040 is the same as the order of the corresponding MSDU MAC header 2280.

(Example 4-3)
In this embodiment, packet aggregation will be described using Packet Aggregation, where 1) the destination is a plurality of MACs, 2) the MPDU header 230 is shared, and 3) CRC is used for the entire MPDU.

  In this embodiment, there is no MSDU type, and the MAC information unit 2020 can be further reduced by sharing all the MPDU headers 230. Since there is no MSDU type, all MSDU types are unified to the type shown in the MPDU type 205. In this case, examples of the MPDU type 205 include a data packet and a QoS packet, and a congested packet cannot exist.

  The schematic configuration of the packet used in this embodiment is the same as that shown in FIG.

  In the case of the present embodiment, the MAC information section 2020 is the MAC information section example 2300 shown in FIG. That is, the MAC information unit 2020 includes an MSDU number 2320, an MSDU MAC header 2330, and respective MSDU length / order number 2350. Note that, as described in the embodiment 4-1, the reply time 2340 (corresponding to the reply time 2140 in the embodiment 4-1) may be included in the MAC unit 2310.

  In this embodiment, the order of the MSDU number 2320, the MSDU MAC header 2330, and the reply time 2340 is arbitrary.

(Example 4-4)
This example is a combination of Example 4-1 and Example 4-3. When transmitting a packet of which the MPDU type is a congestion type, the MPDU is in the format of the embodiment 4-1, and when transmitting a packet of the data type or the QoS type as the MPDU type, the MPDU of the embodiment 4-3 is used. Format. In this case, it is possible to maintain compatibility with the conventional case when transmitting a congestion type packet, and it is possible to reduce the size of the MPDU when transmitting a data type or QoS type packet.

(Example 4-5)
This example is a combination of Example 4-2 and Example 4-3. When transmitting a packet of which the MPDU type is a congestion type, the MPDU is in the format of the embodiment 4-2. When transmitting a packet of the data type or the QoS type as the MPDU type, the MPDU is the Format. In this case, the size of the MPDU can be reduced in both types.

(Example 4-6)
In this example, CRC is applied to each of the MSDUs of Example 4-1 to Example 4-5. Also, CRC is applied collectively to the MPDU type, the number of MACs, and the MAC information part. Thus, it is possible to increase communication reliability by applying CRC to the header part of the MPDU and each MSDU.

  FIG. 26A shows a schematic configuration of a packet used in this embodiment. As shown in the figure, the packet includes CRCH 2030 in addition to MPDU type 2000, MAC number 2010, MAC information unit 2020, and MSDU unit 2040. The CRCH 2030 is a CRC that is arranged after the MPDU type 2000, the MAC number 2010, and the MAC information unit 2020, and is applied to the MPDU type 2000, the MAC number 2010, and the MAC information unit 2020.

  FIG. 26B shows a configuration in which the MSDU example 2400 shown in FIG. 23C is applied to this embodiment. As shown in the figure, the MSDU unit 2040 includes n conventional MPDUs 2410... And n CRC 2420s arranged after each conventional MPDU 2410.

  FIG. 26C shows a configuration in which the MSDU unit example 2500 shown in FIG. 24B is applied to this embodiment. As shown in the figure, the MSDU unit 2040 includes n MSDUs 2510... And n CRC2520s arranged after each MSDU 2510.

  Note that Viterbi, Turbo Code, or LDPC processing is usually used to correct errors that occur in transmission and reception. Also, pad bits generated from these processes are added after each CRC. The above processing is applied to a portion (including CRCH / CRC) corresponding to CRCH / CRC. For example, in FIG. 20, the above processing is applied to the MAC header + CRCH + pad bit and each conventional MPDU or MSDU + CRC + pad bit.

  According to the present embodiment, the reliability can be increased by applying the CRC for each MSDU. However, in order to confirm the communication status of each MSDU, the ACK needs to include the communication status of all MSDUs. The ACK for this purpose is composed of an ACK MAC header 1350 and n bits 1360 as shown in FIG. The number of bits 1360 corresponds to the number of MSDUs included in the packet to be ACKed. Each bit 1360 indicates the communication status of the MSDU included in the packet to be ACKed. For example, if the bit is 1, it indicates communication success, and if it is 0, it indicates communication failure. Further, the order of each bit 1360 corresponds to the order of each MSDU confirmed by the MAC information part included in the packet to be ACKed.

(Example 5-1)
In the present embodiment, an MPDU packet format in which CRC is applied to each of a variable number of MSDUs will be described. According to the present embodiment, since CRC can be applied for each optimum number of MSDUs, it is possible to make a trade-off between the overall length of the MPDU and the reliability of the transmission path.

  FIG. 28A shows a schematic configuration of a packet used in this embodiment. As shown in the figure, the packet includes MPDU type 2600, MAC number 2610, MAC information part 2620, CRC part 2630, CRCH 2640, and MSDU part 2650.

  Since the MPDU type 2600, the MAC number 2610, the MAC information unit 2620, and the CRCH 2640 correspond to the MPDU type 2000, the MAC number 2010, the MAC information unit 2020, and the CRCH 2030, the description thereof is omitted here. .

  As shown in FIG. 28 (b), the CRC unit 2630 includes a CRC unit number 3000 and CRC MSDU numbers 3010. The number of CRC parts 3000 is the number of CRCs included in the MSDU part 2650, which is m. In the example, the first CRC MSDU number 1 is x1, and the last CRC MSDU number m is xm.

  As the MSDU unit 2650, the MSDU unit example 3100 shown in FIG. 28C as corresponding to FIG. 23C, and the MSDU unit example shown in FIG. 28D corresponding to FIG. 3200 can be applied. As shown in these figures, CRC is applied to each of a plurality of MSDUs, and the number of MSDUs to which each CRC is applied corresponds to the CRC MSDU number 3010. In the example MSDU portion 3100, the first CRC 3120 is applied to the first x1 conventional MPDU 3110, and the last CRC 3120 is applied to the last xm conventional MPDU 3110. Similarly, in the example MSDU example 3200, the first CRC 3220 applies to the first x1 MSDUs 3210 and the last CRC 3220 applies to the last xm conventional MSDUs 3210. Others are the same as the corresponding contents, and the description is omitted here.

(Example 6-1)
In the present embodiment, an MPDU packet format in which CRC is applied to each of a fixed number of MSDUs will be described. According to the present embodiment, since CRC is applied to each of a plurality of MSDUs, it is possible to make a trade-off between the overall length of the MPDU and the reliability of the transmission path.

  A schematic configuration of a packet used in this embodiment is shown in FIG. As shown in the figure, the packet includes an MPDU type 3300, a MAC number 3310, a MAC information part 3320, a CRCMSDU number 3330, a CRCH 3340, and an MSDU part 3350.

  Since the MPDU type 3300, the MAC number 3310, the MAC information unit 3320, and the CRCH 3340 correspond to the MPDU type 2000, the MAC number 2010, the MAC information unit 2020, and the CRCH 2030, description thereof is omitted here. .

  The CRCMSDU number 3330 indicates a fixed number of MSDUs between CRCs. In the example, the number of MSDUs is m.

  As the MSDU unit 3350, the MSDU unit example 3700 shown in FIG. 28 (b) corresponding to FIG. 23 (c), and the MSDU unit example shown in FIG. 28 (c) corresponding to FIG. 24 (b). 3800 can be applied. As shown in these figures, CRC 3720 or CRC 3820 is applied to every m MSDU 3710 or MSDU 3810. Also, the last CRC 3720 or 3820 is always applied to the end of the MPDU.

(Example 7-1)
In the present embodiment, each packet format of BAR / BA performed when the packet transmission in the above-described embodiment 1-1 to embodiment 1-5 is performed will be described. In this case, Packet Aggregation is used for packets that are subject to BAR / BA, the destination of all packets is one MAC, and one CRC is applied to the entire MPDU. Whether to use ACK or BAR / BA burst is confirmed by the Ack Policy. Further, in a packet to be subjected to BAR / BA, the MPDU sequence number is added after the MPDU type.

  FIG. 30 shows an outline of the packet configuration of BAR4000 and the packet configuration of BA4100. The BAR 4000 includes a BAR MAC header portion 4010, the number of MPDUs 4020, and sequence numbers 4030.

  The number of MPDUs 4020 indicates the number of MPDUs for which confirmation is requested by the BAR4000. In the example, the number of MPDUs 4020 is n. The sequence number 4030 indicates the sequence number of the MPDU for which confirmation is requested. In the example, n sequence numbers 4030... Are included in the BAR4000. In the BAR4000, the order in which the sequence numbers 4030 ... are arranged is arbitrary.

  Further, the n MPDUs requested for confirmation are the MPDUs transmitted during the normal burst, but it is not necessary to limit the MPDUs during the burst.

  After receiving the BAR4000 as described above, the receiving side creates a BA 4100 and transmits it to the transmitting side. The BA 4100 includes a BA MAC header 4110 and n bits 4120. Each bit 4120 indicates the reception state of the MPDU corresponding to each sequence number 4030 requested to be confirmed by the BAR 4000. When the bit 4120 is 1, it indicates that the MPDU requested for confirmation has been successfully received, and when it is 0, it indicates that the reception has failed.

(Example 7-2)
In the present embodiment, the packet formats of BAR / BA performed when packets are transmitted in Embodiments 1-6, 2-1, and 3-1. In this case, Packet Aggregation is used for a packet that is a target of BAR / BA, and is transmitted to one MAC, and CRC is applied to one or a plurality of MSDUs in the MPDU. Whether to use ACK or BAR / BA burst is confirmed by the Ack Policy.

  FIG. 31 shows an outline of the packet configuration of the BAR 4200 and the packet configuration of the BA 4300. The BAR 4200 includes a BAR MAC header part 4210, an MSDU number 4220, and a sequence number 4230.

  The MSDU number 4220 indicates the number of MSDUs for which confirmation is requested by the BAR 4200. In the example, the number of MSDUs 4220 is n. The sequence number 4230 indicates the sequence number of the MSDU requesting confirmation. In the example, n sequence numbers 4230... Are included in the BAR 4200. In the BAR 4200, the order in which the sequence numbers 4230 ... are arranged is arbitrary.

  Note that the n MSDUs for which confirmation is requested are MSDUs transmitted during a normal burst, but need not be limited to MSDUs in a burst.

  After receiving the BAR 4200 as described above, the receiving side creates a BA 4300 and transmits it to the transmitting side. The BA 4300 includes a BA MAC header 4310 and n bits 4320. Each bit 4320 indicates the reception state of the MPDU corresponding to each sequence number 4230 requested to be confirmed by the BAR 4200. If bit 4320 is 1, it indicates that the MSDU requested for confirmation has been successfully received, and if 0, it may indicate that reception has failed.

(Example 7-3)
In the present embodiment, each packet format of BAR / BA performed when the packet transmission in the above-described embodiment 1-1 to embodiment 1-5 is performed will be described. In this case, Packet Aggregation is used for the BAR / BA target packet, and one CRC is applied to the entire MPDU. In addition, each destination of a BAR / BA target packet is a plurality of MACs. Note that the destination of the MSDU included in each packet is one MAC. Whether to use ACK or BAR / BA burst is confirmed by the Ack Policy. Further, in a packet to be subjected to BAR / BA, the MPDU sequence number is added after the MPDU type.

  FIG. 32 shows an outline of the packet configuration of the BAR 4400 and the packet configuration of the BA 4600. The BAR 4400 includes a BAR frame type 4410, a MAC number 4420, a MAC unit 4430, and a CRC 4440.

  The MAC number 4420 indicates the number of MACs that have transmitted MPDUs for which confirmation is requested by the BAR4000. In the example, the number of MACs 4420 is n.

  The MAC unit 4430 includes n pieces of MAC information 4450. Each MAC information 4450 includes MPDU number 4480 and MPDU sequence number 4490.

  The number of MPDUs 4480 indicates the number of MPDUs to be confirmation requests included in the MAC information 4450. In the case, the MPDU number 4480 is changed to i. m (meaning m included in the i-th MAC information 4450). The sequence number 4490 indicates the sequence number of the MPDU for which confirmation is requested. In the case, i. m sequence numbers 4490... are included in each MAC information 4450. In the MAC information 4450, the order in which the sequence numbers 4490... Are arranged is arbitrary.

  Note that i. The m MPDUs are usually MPDUs transmitted during a burst, but need not be limited to MPDUs in a burst.

  Note that, as shown in the embodiment 4-1, the reply time 4470 (corresponding to the reply time 2140 in the embodiment 4-1) may be included in the MAC information 4450. Here, the BAR frame type 4410 has a reply time Flag, and when the reply time 4470 is required, the reply time Flag is set to 1.

  After receiving the BAR 4400 as described above, the receiving side creates a BA 4600 and transmits it to the transmitting side. BA 4600 includes a BA MAC header 4610, and i. It includes m bits 4620. Each bit 4620 indicates the reception state of the MPDU corresponding to each sequence number 4490 requested to be confirmed by the BAR 4400. If bit 4620 is 1, it indicates that the MPDU requested for confirmation has been successfully received, and if 0, it may indicate that reception has failed.

(Example 7-4)
In this example, the above-described Example 1-1 to Example 1-5, Example 2-1, Example 3-1, Example 4-1 to Example 4-6, Example 5-1, and Each packet format of BAR / BA performed when the packet transmission in Example 6-1 is performed will be described. In this case, Packet Aggregation is used for the BAR / BA target packet, and CRC is applied to one or more MSDUs in the MPDU. In addition, the destination of the MSDU included in each packet to be BAR / BA is one or more MACs. Whether to use ACK or BAR / BA burst is confirmed by the Ack Policy.

  FIG. 33 shows an outline of the packet configuration of BAR4700 and the packet configuration of BA4900. The BAR 4700 includes a BAR frame type 4710, a MAC number 4720, a MAC unit 4730, and a CRC 4740.

  The MAC number 4720 indicates the number of MACs that transmitted the MSDU requesting confirmation by the BAR 4700. In the example, the number of MACs 4720 is n.

  The MAC unit 4730 includes n pieces of MAC information 4750. Each MAC information 4750 includes an MSDU number 4780 and an MSDU sequence number 4790.

  The MSDU number 4780 indicates the number of MSDUs to be a confirmation request included in the MAC information 4750. In the case, MSDU number 4780 is changed to i. m (meaning m included in the i-th MAC information 4450). The sequence number 4790 indicates the sequence number of the MSDU requesting confirmation. In the case, i. m sequence numbers 4790... are included in each MAC information 4750. In the MAC information 4750, the order in which the sequence numbers 4790 ... are arranged is arbitrary.

  Note that i. The m MSDUs are usually MSDUs transmitted during a burst, but need not be limited to MSDUs in a burst.

  Note that, as shown in the embodiment 4-1, the reply time 4770 (corresponding to the reply time 2140 in the embodiment 4-1) may be included in the MAC information 4750. Here, the BAR frame type 4710 has a reply time Flag, and when the reply time 4770 is required, the reply time Flag is set to 1.

  After receiving the BAR 4700 as described above, the receiving side creates a BA 4900 and transmits it to the transmitting side. BA 4900 includes a BA MAC header 4910, and i. It includes m bits 4920. Each bit 4920 indicates the reception state of the MSDU corresponding to each sequence number 4790 requested to be confirmed by the BAR 4700. If bit 4920 is 1, it indicates that reception of the MSDU requested for confirmation is successful, and if it is 0, it indicates that reception has failed.

(Example 8-1)
In this embodiment, the packet format of MPDU when MIMO is used will be described. A condition for transmission by MIMO is that signals are transmitted simultaneously by all antennas. Therefore, MIMO transmission can be realized by applying Packet Aggregation as a format of a packet transmitted by each antenna. Therefore, this example is based on Example 1-1 to Example 1-5, Example 2-1, Example 3-1, Example 4-1, Example 4-6, Example 5 of Packet Aggregation. 1 and an application example for packet transmission in the embodiment 6-1.

  When MIMO is used, since it is necessary to transmit data simultaneously with all antennas, the MSDU is appropriately divided and included in the MPDU. In this case, it is necessary to confirm transmission by ACK or BAR / BA in units of MSDU division. Therefore, the MSDU division number is also included in the MSDU sequence number in the MPDU.

(Example 8-2)
In this embodiment, an ACK packet format when transmitting to one MAC using MIMO and using one CRC for the entire MPDU will be described. The present embodiment is an application example for packet transmission in the embodiment 1-1 to the embodiment 1-5 using the packet aggregation.

  The ACK returned by all antennas is the same, and the format of each ACK is as shown in FIG. The ACK includes an ACK MAC header 5000 and n bits 5010. n is the number of antennas, and each bit 5010 is MPDU confirmation information of each antenna transmitted by MIMO. Each bit 5010 indicates the communication status of each MPDU according to the antenna order. If it is 1, it indicates that reception is successful, and if it is 0, it indicates that reception has failed. Good.

(Example 8-3)
In the present embodiment, a packet format of ACK when transmitting to one MAC using MIMO and using CRC for each one or a plurality of MSDUs will be described. The present embodiment is an application example to the first to sixth embodiments, the second embodiment, and the third embodiment using the packet aggregation.

  The ACK returned by all antennas is the same, and the format of each ACK is as shown in FIG. The number n of bits 5010 is the total number of MSDUs transmitted by all antennas, and each bit 5010 is confirmation information of these MSDUs. Each bit 5010 indicates the communication status of each MSDU according to the MSDU order of the transmitted antenna order.

(Example 8-4)
In the present embodiment, an ACK packet format when transmitting to a plurality of MACs using MIMO and using one CRC for the entire MPDU will be described. In addition, MPDU which transmitted the whole MPDU only to one MAC by one antenna is also included. The present embodiment is an application example to the embodiment 1-1 to the embodiment 1-5 using the packet aggregation.

  The ACK in all antennas returned from one MAC is the same, and the format of each ACK is as shown in FIG. The number n of bits 5010 is the number of antennas, and each bit 5010 is MPDU confirmation information of each antenna transmitted by MIMO. Each bit 5010 indicates the communication status of each MPDU according to the antenna order. Each MAC returns an ACK according to its reply time.

(Example 8-5)
In this embodiment, an ACK packet format when transmitting to a plurality of MACs using MIMO and using CRC for one or a plurality of MSDUs will be described. The present example is an application example to Example 4-1 to Example 4-6, Example 5-1, and Example 6-1 using Packet Aggregation.

  The ACK in all antennas returned from one MAC is the same, and the format of each ACK is as shown in FIG. The number n of bits 5010 is the total number of MSDUs transmitted by all antennas to the MAC that returns an ACK, and each bit 5010 is confirmation information of these MSDUs. Each bit 5010 indicates the communication status of each MSDU according to the MSDU order of the transmitted antenna order.

  Each MAC returns an ACK according to its reply time.

(Example 9-1)
In this embodiment, a packet format of BAR / BA when transmitting to one MAC using MIMO and using CRC for the entire MPDU will be described. The BAR / BA transmitted and received by all antennas is the same, and this embodiment is an application example to the embodiment 7-1.

  MPDUs to be confirmed by BAR are all MPDUs transmitted by all antennas, the transmitting side transmits the same BAR by all antennas, and the receiving side transmits the communication status (BA) for all these MPDUs by all antennas. Send back.

(Example 9-2)
In this embodiment, a packet format of BAR / BA when transmitting to one MAC using MIMO and using CRC for each one or a plurality of MSDUs will be described. The BAR / BA transmitted and received by all antennas is the same, and this embodiment is an application example to the embodiment 7-2.

  MSDUs to be checked by BAR are all MSDUs transmitted by all antennas, the transmitting side transmits the same BAR by all antennas, and the receiving side transmits the communication status (BA) for all these MSDUs by all antennas. Send back.

(Example 9-3)
In this embodiment, a packet format of BAR / BA when transmitting to a plurality of MACs using MIMO and using CRC for the entire MPDU will be described.

  The BAR transmitted and received by all antennas is the same, and the BAs of all antennas returned by one MAC are the same. This example is an application example to Example 7-3.

  MPDUs to be confirmed by the BAR are all MPDUs transmitted by all antennas for each transmitted MAC, and the transmission side transmits the same BAR by all antennas. The MAC on the receiving side returns the communication status (BA) for all MPDUs requested to be confirmed to itself at the BA reply time using all antennas.

(Example 9-4)
In this embodiment, a packet format of BAR / BA when transmitting to a plurality of MACs using MIMO and using CRC for one or a plurality of MSDUs will be described.

  The BAR transmitted and received by all antennas is the same, and the BAs of all antennas returned by one MAC are the same. This embodiment is an application example to the embodiment 7-4.

  The MSDUs confirmed by the BAR are all MSDUs transmitted by all antennas for each transmitted MAC, and the transmitting side transmits the same BAR by all antennas. The MAC on the receiving side returns the communication status (BA) for all MSDUs requested to be confirmed to itself at the BA reply time using all antennas.

  The present invention is not limited to the above-described embodiments and examples, and various modifications can be made within the scope shown in the claims, and technical means disclosed in different embodiments and examples respectively. Embodiments obtained by appropriate combinations are also included in the technical scope of the present invention.

  Note that each unit and each processing step of the transmission side communication device 1 and the reception side communication device 2 in the embodiment described above is a program stored in a storage unit such as a ROM (Read Only Memory) or a RAM by a calculation unit such as a CPU. It can be realized by executing and controlling communication means such as an interface circuit. Therefore, the computer having these means reads the recording medium in which the program is recorded and executes the program to perform the various functions and various processes of the transmission side communication device 1 and the reception side communication device 2 of the present embodiment. Can be realized. In addition, by recording the program on a removable recording medium, the various functions and various processes described above can be realized on an arbitrary computer.

  As this recording medium, a program medium such as a memory (not shown) such as a ROM may be used for processing by the microcomputer, or a program reader is provided as an external storage device (not shown). It may be a program medium that can be read by inserting a recording medium therein.

  In any case, the stored program is preferably configured to be accessed and executed by the microprocessor. Furthermore, it is preferable that the program is read out, and the read program is downloaded to a program storage area of the microcomputer and the program is executed. It is assumed that this download program is stored in advance in the main unit.

  The program medium is a recording medium configured to be separable from the main body, such as a tape system such as a magnetic tape or a cassette tape, a magnetic disk such as a flexible disk or a hard disk, or a disk such as a CD / MO / MD / DVD. Fixed disk, IC card (including memory card), etc., or semiconductor ROM such as mask ROM, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), flash ROM, etc. In particular, there are recording media that carry programs.

  In addition, if the system configuration is capable of connecting to a communication network including the Internet, the recording medium is preferably a recording medium that fluidly carries the program so as to download the program from the communication network.

  Further, when the program is downloaded from the communication network as described above, it is preferable that the download program is stored in the main device in advance or installed from another recording medium.

(The invention's effect)
A communication apparatus according to the present invention transmits aggregate packets generated by the aggregate packet generation means to the reception apparatus, and performs aggregate packet generation means for performing a process of combining a plurality of packets to be transmitted into one aggregate packet. A communication unit that performs error check processing for each packet to be transmitted. Thus, even if an error occurs in one of the packets included in the aggregate packet, the remaining packets can be transmitted normally. Therefore, there is an effect that transmission efficiency can be improved.

  The communication device according to the present invention includes a packet generation unit that generates a transmission packet, and a communication unit that transmits the transmission packet generated by the packet generation unit to the reception device, and the packet generation unit generates the transmission packet. A reply time calculating means for calculating a reply time of a delivery confirmation packet by the receiving side with respect to the transmission packet to be transmitted, wherein the packet generating means includes the reply time information in the transmission packet. Accordingly, for example, when transmission packets are simultaneously transmitted to a plurality of communication devices, it is possible to prevent a situation such as collision of transmission of delivery confirmation from each communication device.

  The communication apparatus according to the present invention includes: an aggregate packet generation unit that performs processing for collecting a plurality of packets to be transmitted into one aggregate packet; and transmission of an acknowledgment packet for each of the packets included in the aggregate packet. A delivery confirmation requesting means for generating a delivery confirmation request packet for making a request to the receiving side of the receiver, an aggregate packet generated by the aggregate packet generating means, and a delivery confirmation request packet generated by the delivery confirmation requesting means And a communication unit that transmits to the receiving device, wherein the delivery confirmation request packet includes information for specifying a packet that is a target for requesting delivery confirmation. Thus, there is an effect that it is possible to increase the number of packets to be confirmed for delivery only by adding information for identifying packets. Note that there is a limitation on the number of packets that represent the number of packets in the number of packets that are one delivery confirmation target. For example, when the information for the number of packets in the information specifying the packet is 16 bits, the limit on the number of packets is 2 ^ 16-1 = 65535.

  A communication apparatus according to the present invention transmits aggregate packets generated by the aggregate packet generation means to the reception apparatus, and performs aggregate packet generation means for performing a process of combining a plurality of packets to be transmitted into one aggregate packet. A common information extracting means for extracting common information common to all of the plurality of packets to be transmitted included in the aggregate packet, and including the common information in the aggregate packet. And an aggregate packet reconstruction means for generating the aggregate packet after deleting the common information from at least one of the packets to be transmitted. As a result, the size of the aggregate packet can be further reduced as compared to a case where a plurality of packets are simply combined into an aggregate packet. As a result, the packet transmission efficiency can be improved.

  A communication apparatus according to the present invention transmits aggregate packets generated by the aggregate packet generation means to the reception apparatus, and performs aggregate packet generation means for performing a process of combining a plurality of packets to be transmitted into one aggregate packet. And the aggregate packet generation means divides at least one packet among a plurality of packets to be transmitted into a plurality of packets, and allocates each divided packet to a plurality of aggregate packets. As a result, the degree of freedom of the configuration of the aggregate packet can be increased, and there is an effect that it is possible to appropriately cope with the case where the size of the aggregate packet needs to be adjusted for some reason. .

  The communication apparatus according to the present invention can be applied to, for example, a communication apparatus used for a transmission apparatus capable of transmitting stream data such as moving image data and other data to an external apparatus. Specifically, examples of the transmitting device include a device having a function of reproducing a moving image recorded as a digital code such as a DVD player, a DVD recorder, and an HDD recorder, and a broadcast receiving device such as a BS / CS tuner.

  The communication apparatus according to the present invention can be applied to a communication apparatus used for a reception apparatus that performs processing based on received stream data and other data, for example. Specifically, examples of the receiving device include a display device that displays moving image data as received stream data.

It is a block diagram which shows schematic structure of the transmission side communication apparatus which concerns on one Embodiment of this invention. It is a block diagram which shows schematic structure of the receiving side communication apparatus which concerns on one Embodiment of this invention. 1 is a block diagram showing a schematic configuration of a communication network system according to an embodiment of the present invention. It is a figure which shows the format example of a packet in the case of transmitting MSDU which is respectively different by a some antenna by MIMO. It is a figure which shows the other example of the format example in the case of transmitting MSDU which is respectively different by a some antenna by MIMO. It is a figure which shows the further another example of the format example of a packet in the case of transmitting MSDU which is respectively different by a some antenna by MIMO. It is a figure which shows the structural example of the packet in the case of performing an error check process for every MSDU contained in an aggregate packet. It is a figure which shows the structural example of the packet in the case of performing an error check process for every several MSDU contained in an aggregate packet. It is a figure which shows the example of the collective packet transmitted by each transmission antenna at the time of using two transmission antennas. In FIG. 6A, an ACK for an MSDU or an MSDU divided portion transmitted from a certain transmitting antenna is transmitted from a receiving antenna corresponding to the receiving antenna that has received the corresponding MSDU or MSDU divided portion. FIG. 4B is a diagram illustrating an example in which all MSDUs transmitted by a plurality of antennas or ACKs corresponding to divided parts of MSDUs are returned. FIG. 4A is a diagram illustrating an example in which a plurality of divided packets divided from one packet are transmitted by different antennas. FIG. 2B and FIG. It is a figure which shows the example by which the some divided | segmented packet is each transmitted by the same antenna. It is a figure which shows the example which applied the example of transmission shown to FIG.11 (b) and FIG.11 (c) to ACK. FIG. 4A is a diagram illustrating a configuration example of the MAC header in the MPDU, and FIG. 4B is a diagram illustrating a configuration example of the MAC header in the MSDU. FIG. 4A is a diagram showing a schematic configuration of a packet used in one embodiment of the present invention, and FIG. 2B is a diagram showing an example of a MAC information part used in one embodiment of the present invention. FIG. 4C is a diagram showing an example of the MSDU unit used in one embodiment of the present invention. FIG. 4A is a diagram showing an example of a MAC information unit used in another embodiment of the present invention, and FIG. 4B is a diagram showing an example of an MSDU unit used in another embodiment of the present invention. It is. It is a figure which shows the example of a MAC information part used in the further another Example of this invention. FIG. 5A is a diagram showing a schematic configuration of a packet used in still another embodiment of the present invention. FIG. 5B and FIG. 5C are diagrams in still another embodiment of the present invention. It is a figure which shows the MSDU part example used. FIG. 4A is a diagram showing a schematic configuration of a packet used in still another embodiment of the present invention, and FIG. 4B shows an example of a CRC unit used in still another embodiment of the present invention. FIG. 6C is a diagram showing an example of an MSDU unit used in still another embodiment of the present invention. It is a figure which shows the MSDU part example used in the further another Example of this invention. It is a figure which shows the example of application of CRCH and CRC. It is a figure which shows schematic structure of ACK used in the Example of this invention. FIG. 5A is a diagram showing a schematic configuration of a packet used in still another embodiment of the present invention. FIG. 5B and FIG. 5C are diagrams in still another embodiment of the present invention. It is a figure which shows the MSDU part example used. FIG. 4A is a diagram showing a schematic configuration of a packet used in still another embodiment of the present invention, and FIG. 4B is an example of a MAC information part used in still another embodiment of the present invention. FIG. 8C is a diagram showing an example of an MSDU unit used in still another embodiment of the present invention. FIG. 4A is a diagram showing an example of a MAC information unit used in still another embodiment of the present invention, and FIG. 4B is an example of an MSDU unit used in still another embodiment of the present invention. FIG. It is a figure which shows the example of a MAC information part used in the further another Example of this invention. FIG. 5A is a diagram showing a schematic configuration of a packet used in still another embodiment of the present invention. FIG. 5B and FIG. 5C are diagrams in still another embodiment of the present invention. It is a figure which shows the MSDU part example used. It is a figure which shows the order of the ACK reply by several MAC. FIG. 4A is a diagram showing a schematic configuration of a packet used in still another embodiment of the present invention, and FIG. 4B is a configuration of a CRC unit used in still another embodiment of the present invention. (C) and (d) are diagrams showing an example of an MSDU part used in still another embodiment of the present invention. FIG. 5A is a diagram showing a schematic configuration of a packet used in still another embodiment of the present invention. FIG. 5B and FIG. 5C are diagrams in still another embodiment of the present invention. It is a figure which shows the MSDU part example used. It is a figure which shows the outline of the packet structure of BAR used in the further another Example of this invention, and the packet structure of BA. It is a figure which shows the outline of the packet structure of BAR used in the further another Example of this invention, and the packet structure of BA. It is a figure which shows the outline of the packet structure of BAR used in the further another Example of this invention, and the packet structure of BA. It is a figure which shows the outline of the packet structure of BAR used in the further another Example of this invention, and the packet structure of BA. It is a figure which shows the outline of the packet structure of ACK used in the further another Example of this invention. It is a figure which shows schematic structure of the communication system using MIMO. FIG. 4A is a diagram showing a transmission form by a single link, and FIG. 4B is a graph showing a frequency spectrum of a signal at the time of transmission and a frequency spectrum of the signal at the time of reception. (C) is a figure which shows the transmission form by MIMO when the number of transmitting antennas and the number of receiving antennas are two. It is a schematic diagram of the packet sequence of the example which succeeded in the transmission of the QoS packet, and the example which failed. It is a figure which shows the transmission example at the time of using ACK. FIGS. 7A and 7B are diagrams illustrating an example of a packet sequence of a transmission packet using packet aggregation. It is a figure which shows the transmission frame (packet) processed in the MAC layer of IEEE802.11. FIGS. 4A and 4B are diagrams showing packet sequence examples of aggregate packets when Packet Aggregation is adapted to IEEE 802.11. It is a figure which shows the example in which the whole MPDU becomes an error when one MSDU becomes an error when Packet Aggregation is used. It is a figure which shows the example of a packet sequence when the system figure when one communication station transmits MSDU to two communication stations simultaneously, and the collision of ACK has arisen. The figure (a) is a figure which shows the example of a packet sequence when the collision of a system diagram when one communication station transmits MSDU to two communication stations simultaneously, and ACK collision is avoided, (b) These are a system diagram and a packet sequence example when two communication stations on the receiving side cannot grasp the communication status of each other. It is a figure which shows the state at the time of performing packet transmission in the same time in the some antenna from which transmission speed differs mutually. It is a figure which shows the state at the time of performing packet transmission of the same data amount in the some antenna from which a transmission speed differs mutually. It is a figure which shows the transmission form which transmits / receives one signal AB in MIMO which made the number of transmitting antennas and the number of receiving antennas two. It is a figure which shows the example in case transmission of BAR is performed when an error arises in ACK with respect to an aggregate packet. It is a figure which shows the example when the reply of ACK fails after transmission of an aggregate packet is performed. It is a figure which shows the example in case the aggregate packet number which identifies an aggregate packet is set to the aggregate packet, and transmission of an ACK resending request packet is performed. When the entire aggregate packet for which the aggregate packet number is set becomes an error, and the transmission side communication device detects the channel busy state at the ACK reception timing but the packet reception is not performed normally, the ACK retransmission request packet It is a figure which shows the example in case transmission is performed.

Claims (9)

A communication device for performing communication in a communication network,
Aggregate packet generation means for performing a process of combining a plurality of packets to be transmitted into one aggregate packet;
Communication means for transmitting the aggregate packet generated by the aggregate packet generation means to a receiving device;
The communication device further comprises a delivery confirmation request means for generating a delivery confirmation request packet for requesting the reception device to return delivery confirmation information for each packet included in the aggregate packet;
The communication means transmits the delivery confirmation request packet to the receiving apparatus when the communication means fails to normally receive the delivery confirmation packet for the aggregate packet at a timing at which it should be received from the receiving apparatus. Communication device.   The communication apparatus according to claim 1, wherein the delivery confirmation request packet includes information for identifying a packet that is a request for delivery confirmation. Communication apparatus according to claim 1, characterized in that it comprises identification information of the packet transmission acknowledgment request packet is included in the aggregation packet. The aggregate packet generation means adds an aggregate packet number for identifying each aggregate packet to each aggregate packet;
Communication apparatus according to claim 1, wherein said acknowledgment request unit is characterized in that it comprises a collection packet number relative to the delivery confirmation request packet.   2. The communication apparatus according to claim 1, further comprising error check processing means for performing error check processing for each of the one or more packets to be transmitted. A communication device that receives an aggregate packet from the communication device according to claim 2 or claim 3 ,
A reception state detection means for detecting a reception state of the aggregate packet or packet;
A delivery confirmation generating means for generating a bitmap corresponding to the aggregate packet or packet according to a detection result by the reception state detecting means, and generating a delivery confirmation packet including the bitmap;
And a communication unit that transmits the delivery confirmation packet. A communication method in a communication device for communicating with a receiving device in a communication network,
A collective packet generation process for performing a process of combining a plurality of packets to be transmitted into one collective packet;
A communication process of transmitting the aggregate packet generated by the aggregate packet generation process to the receiving device,
The communication process further includes a delivery confirmation request process for generating a delivery confirmation request packet for requesting a reception apparatus to return delivery confirmation information for each packet included in the aggregate packet;
The communication device transmits the delivery confirmation request packet to the receiving device when the communication device fails to receive the delivery confirmation packet for the aggregate packet from the receiving device at a timing at which it should be received normally. Communication method. The communication program which makes a computer perform each means with which the communication apparatus as described in any one of Claims 1 thru | or 6 is provided. Recording medium storing a communication program for executing the respective means provided in the communication apparatus according to a computer in any one of claims 1 to 6.

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